Tag Archives: controversy

The Controversies of Corticosteroids in Sepsis

Author: Brit Long, MD (@long_brit, EM Attending Physician at SAUSHEC, USAF) // Edited by: Jamie Santistevan, MD (@Jamie_Rae_EMdoc, Admin and Quality Fellow at UW, Madison, WI) and Alex Koyfman, MD (@EMHighAK, EM Attending Physician, UTSW Medical Center / Parkland Memorial Hospital) 

A 54-year-old male with a history of recent antibiotic therapy is currently being managed for pneumonia with IV antibiotics including cefepime, levofloxacin, and vancomycin. Despite 6L of IV fluids and norepinephrine at 20 micrograms/minute IV infusion, his blood pressure remains at 70/42, with a heart rate of 112. Bedside US reveals a hyperdynamic heart and IVC 2 cm in size. His electrolytes reveal a sodium of 135 and potassium of 4.9. What could you be missing? Should you start corticosteroids? What about the side effects?

Sepsis is a condition emergency providers manage daily, with over 750,000 septic patients seen in the emergency department (ED) per year.1-4 Septic shock is severe, with mortality ranging from 20% to 70%.1-4

Sepsis management requires rapid diagnosis, early administration of intravenous (IV) fluids with broad-spectrum antimicrobials, and source control. Early Goal-Directed Therapy (EGDT) first brought these elements to the forefront of emergency medicine,5 with further modifications in the ProCESS, ARISE, and ProMISe trials.6-9 Specific components of sepsis management remain essential including fluid resuscitation, broad-spectrum antimicrobials, and vasopressors.6-9

The Controversy

The systemic response of sepsis includes pro-inflammatory pathways and cytokines. Corticosteroids can act to attenuate these inflammatory molecules, suggesting a possible role for corticosteroid use.3,10 Vasomotor tone may decrease in septic shock, and corticosteroids can improve vascular function and organ perfusion.3,10

Septic shock can be associated with relative adrenal insufficiency, in which a patient’s endogenous cortisol levels are not sufficient to maintain hemodynamic status. Studies demonstrate conflicting results with steroid use in these patients. The role of corticosteroid therapy in patients with vasopressor-resistant septic shock remains controversial, specifically whether corticosteroids reduce mortality or reduce time of shock and vasopressor need. Despite recent meta-analyses, no clear guidance exists on corticosteroid indications and which patients truly benefit.11-17

Sepsis and the Hypothalamic–Pituitary–Adrenal (HPA) Axis

Sepsis has many effects on the body, including the HPA axis. The hypothalamus is responsible for stimuli integration and secretion of corticotropin-releasing hormone (CRH) during times of stress.10,11,16,17 This secretion of CRH results in initiation of adrenal corticotropin hormone (ACTH) synthesis in the anterior pituitary. ACTH results in cortisol production from the adrenals, with the entire system regulated through feedback. Severe sepsis and septic shock result in decreased albumin and corticosteroid binding proteins, which decrease total cortisol.16,17

Normal serum cortisol levels vary based on stress and time of day, ranging from 5 to 24 mcg/dL. Levels may reach 50 mcg/dL during periods of peak stress.16-21 Critical illness affects cortisol through multiple mechanisms.17,20-23

Physiologic Stress and Cortisol Effects
– Reduced cortisol breakdown, resulting in increased levels and decreased production.

– Increased cortisol due to decreased breakdown in the setting of renal dysfunction.

– Cortisol binding globulin and albumin decrease, increasing free cortisol.

– Cytokines with inflammatory effects increase steroid receptor affinity, decrease steroid inactivation, and increase peripheral production of cortisol.

Relative adrenal insufficiency is based on several factors. First, stress results in cortisol increase, and as stress increases, cortisol level increases. The incidence of relative adrenal malfunction can approach 50% in severe sepsis and septic shock, due to impaired glucocorticoid and vasopressin production and dysregulated cortisol response.11-17 Medications such as etomidate, antifungals, and chronic steroid use act to decrease intrinsic corticosteroid production and affect protein binding.24,25

Septic Shock and Steroids

Steroids have been utilized in the treatment of septic shock for over 50 years.26-33 From the 1950s to the 1980s, high-dose steroids such as methylprednisolone 30 mg/kg or dexamethasone 3-6 mg/kg were used to treat patients in septic shock.30-33 Schumer et al. compared high dose corticosteroids versus normal saline, finding patients in the normal saline group experienced higher mortality.28 However, the mid-1980s ushered in several trials that did not demonstrate improved mortality in high-dose steroids.34-36 Cronin et al. found increased rate of morbidity and mortality in the high-dose steroid groups.37 Specific subpopulations in these studies experienced harm with high-dose steroids, bringing to a close this therapy.

In the 1990s, physiologic-dose steroids for patients in septic shock demonstrated trends towards improved mortality. Two of the most commonly quoted studies include the Annane and CORTICUS trials. Annane et al. randomized 300 patients with septic shock within 8 hours of diagnosis to hydrocortisone 50 mg IV every 6 hours with fludrocortisone 50 micrograms for 7 days versus placebo.38 All patients underwent a 250 microgram IV ACTH stimulation to evaluate for adrenal dysfunction, which the investigators defined as < 9 microgram/dL increase in total cortisol at 60 minutes. The primary endpoint included 28-day survival for the ACTH nonresponders, with secondary outcomes of total mortality, length of vasopressor requirements, and adverse events from steroid treatment. Low-dose steroid therapy was associated with improved mortality (28-day mortality 53% in steroid group versus 63%), which is based on an adjusted analysis, with no change in adverse events between groups. However, analysis of the complete data set suggests no mortality benefit for steroids. The 28-day mortality rate was not significantly decreased in ACTH stimulation test nonresponders.38 Median time to vasopressor withdrawal was decreased in the steroid group (7 versus 10 days). Oppert et al. suggested improved shock reversal and decreased cytokines in patients treated with hydrocortisone 50 mg IV, followed by 0.18 mg/kg/hr IV infusion.39

These studies were followed by meta-analyses suggesting reduced mortality with physiologically dosed steroids, which found improved hemodynamic effects with corticosteroids at physiologic-doses.40-42 The CORTICUS trial released in 2008 slowed the momentum of support for low-dose steroids.43 This study was a multicenter, prospective, double-blind trial of patients randomized to receive hydrocortisone 50 mg IV every 6 hours versus placebo. Patients were included only if they experienced hypotension for > 1 hour, with primary outcome 28-day mortality in ACTH nonresponders. Investigators in this study found no difference between hydrocortisone and placebo groups in 28-day mortality (39% versus 36%, respectively).43 Similar to Annane et al., the CORTICUS trial found reduced time to shock reversal with hydrocortisone, but higher rates of hyperglycemia, hypernatremia, and superinfection were found in the steroid group.38,43,44

Study Patients Included Definition of shock Intervention Outcome Secondary Outcome
Annane 300 adults with onset of shock within 8 hours, higher illness severity (SAPS II score)

 

All had short corticotropin test

Sepsis with SBP < 90 mm Hg despite fluid replacement, >5ug/kg dopamine or current treatment with epinephrine/ norepinephrine, lactate > 2 mmol/L, need for mechanical ventilation, within 3 hours of onset Hydrocortisone 50 mg IV every 6 hours for 1 week with fludrocortisone 50 mcg once daily for 1 week vs. placebo Improved 28-day survival distribution from randomization in nonresponder short corticotropin test: median time to death 12 vs 24 days,

hazard ratio 0.67; 95% C.I. 0.47-0.95, P=0.02, NNT 7 (95% C.I. 4-49)

 

No statistical difference mortality in ACTH responders, 53% vs. 61% P=0.96, or all patients, 61% vs. 55%

Median time to vasopressor withdrawal in nonresponders: 7 days in treated group, 10 days in placebo group
CORTICUS 499 adults with onset of shock within 72 hours, lower illness severity Sepsis and shock defined by SBP < 90 mm Hg despite 1 hour of fluid resuscitation or need for vasopressors, organ dysfunction attributable to shock Hydrocortisone 50 mg IV every 6 hr, tapering from day 6 to day 12 vs. placebo No change in 28-day mortality in nonresponders: 39.2% in hydrocortisone vs. 36.1% in placebo group, not statistically different.

 

 

No difference in 28-day mortality in short corticotropin responders or all patients.

 

Reduction in time to shock reversal with hydrocortisone. 3.3 days vs. 5.8 days

 

Nonsignificant increase in superinfections in hydrocortisone group: 33% vs. 26% (95% CI 0.96-1.68)

 Shock Attenuation

Corticosteroids may not decrease mortality at physiologic doses, but they do possess important effects. Patients with septic shock given corticosteroids demonstrate decreased need for vasopressors, which has the potential benefit of improving peripheral vascular recovery and organ function.11-15,38,42 Sligl et al. in 2009 found no statistical difference in mortality (42.2% [369 of 875 patients] vs. 38.4% [384 of 1001]; RR, 1.00; 95% CI, 0.84-1.18), but did find a change in incidence of shock reversal at 7 days in the steroid versus placebo groups (64.9% [314 of 484 patients] vs. 47.5% [228 of 480]; RR, 1.41; 95% CI, 1.22-1.64) and no increase in superinfection.14 Wang et al. in a 2014 meta-analysis found low dose hydrocortisone therapy decreased shock at 7 and 28 days, with no change in mortality.45 Faster time to shock reversal but no mortality benefit has been observed in another meta-analysis.46

Steroid Adverse Events

Corticosteroids affect multiple organ systems, and excess amounts are associated with adverse events including hyperglycemia, secondary infection from immunosuppression, delayed healing, skin breakdown, and muscle weakness.14,43,46-48 The CORTICUS trial suggested an increase in infection, with relative risk 1.27 (95% CI 0.96-1.68).43 However, this risk is not statistically different among the groups. Other meta-analyses do not suggest any increase in superinfection with corticosteroids.43

Elevated blood sugar is common, specifically as the dose of steroids increases.47,48 Episodes of hyperglycemia may cause harm, but treating hyperglycemia with insulin increases risk of hypoglycemia. Other issues with steroids include decreased skin integrity and delayed healing, though these are seen in high-doses. ICU patients may experience increased risk of critical illness myoneuropathy, prolonged weakness, increased length of stay, and prolonged mechanical ventilation.47,48

Many of these risks are not significant with physiologic-dose steroids, and they are more relevant to critical care physicians, rather than the ED.

What about evaluating adrenal function?

A great deal of controversy surrounds measuring adrenal function. Cortisol levels drastically change hour to hour due to corticosteroid-binding protein levels and activity, albumin production, and cortisol production during illness.21,49-52 Total cortisol levels are usually measured, though only free cortisol is active. Thus, total cortisol levels are difficult to interpret.49-52 Literature repeatedly demonstrates random serum cortisol is not beneficial due to wide range of baseline levels. Free cortisol may accurately reflect HPA axis activity, but studies do not support correlation of plasma levels with true tissue levels.

Evaluating adrenal function classically entails drawing baseline cortisol levels, administration of cosyntropin (or corticotropin), and reassessment of cortisol at 30 and 60 minutes. Low dose stimulation test uses cosyntropin 1 microgram IV, while high dose uses 250 micrograms IV. However, patients undergoing high dose testing demonstrate response even if they possess adrenal insufficiency due to the high dose of cosyntropin.50 Studies suggest the low dose testing may be more sensitive in diagnosing adrenal insufficiency, though sensitivities for diagnosing adrenal insufficiency approximate 50%. Patients with less than 9 mcg/dL response have greater mortality, along with those with higher baseline levels (34 mcg/dL).56,57

However, testing adrenal function via ACTH stimulation tests in critically ill patients is not reliable. Some patients demonstrate cortisol response > 9 mcg/dL with no cosyntropin administration, questioning this threshold.50,57-61 Many laboratories use immunoassay tests that are not available in many institutions and take days to result, along with poor correlation with gold standard mass spectrometry. At this time, these tests are not reliable for ED use and are even questionable for the ICU.57-60

Steroid Considerations in the ED

The Surviving Sepsis Guidelines advise consideration of corticosteroids for septic shock refractory to fluids and vasopressors.2 They do not recommend the use of corticotropin testing.2 Steroids can improve hemodynamic status, but literature does not support mortality benefit.11-15,38,40,43 Steroids can be used to reduce duration of septic shock in fluid and vasopressor-resistant hypotension.11-15,38,43 However, steroids are associated with side effects including hyperglycemia, myopathy, and electrolyte derangements.47,48

In septic shock, rapid diagnosis and management is integral with antimicrobials, source control, and IV fluid resuscitation. Vasopressors should be used when fluids do not increase MAP above 65 mm Hg.2,10 If the patient does not respond to these treatments, providers should evaluate for steroid indications including patient chronic baseline steroid use, chronic adrenal insufficiency, and refractory hypotension. Patients responsive to fluids and/or vasopressors receive little benefit, if any, from steroids. Contraindications should be considered including potential risk of worsening myopathy, DKA, HIV, TB, recent surgery or open wounds, and active peptic ulcer disease. If these are present, steroids should be avoided if possible. Other considerations include patient physiologic reserve (presence of other comorbidities, response to treatment, and exposure to other adrenal-suppressing agents such as etomidate).

Regimens for corticosteroids include hydrocortisone 100 mg IV every 8 hours or 50 mg IV every 6 hours. Another option is 100 mg IV bolus followed by infusion of 0.18 mg/kg/hr IV. These regimens have not been compared directly. Fludrocortisone is not advised at this time, as the COIITSS study demonstrated increased risk of infection with fludrocortisone in conjunction with corticosteroids.61 The ADRENAL study is currently underway, comparing low-dose corticosteroids in ICU septic shock, with primary outcome of mortality at 90 days.62

Summary

– Sepsis management requires early recognition, fluid resuscitation, source control, broad spectrum antimicrobials, and vasopressors for those not responsive to IV fluids.

– Patients with septic shock unresponsive to fluid and vasopressor resuscitation warrant further management and consideration of other disease states.

– The pathophysiology of sepsis may include loss of vasomotor tone and relative adrenal insufficiency.

– High-dose corticosteroids may result in patient harm, but physiologic, or low-dose, corticosteroids may be used to decrease the need for vasopressors.

– Most current meta-analyses do not demonstrate a mortality benefit with steroids. The Surviving Sepsis Guidelines advise consideration of corticosteroids in patients with vasopressor and fluid resistant septic shock.

– Corticosteroids may decrease need for vasopressors and improve perfusion.

 

References/Further Reading

  1. Elixhauser A, Friedman B, Stranges E. Septicemia in U.S. Hospitals, 2009. Agency for Healthcare Research and Quality, Rockville, MD. http://www.hcup-us.ahrq.gov/reports/statbriefs/sb122.pdf
  2. Dellinger RP, Levy MM, Rhodes A, et al. Surviving sepsis campaign: international guidelines for management of severe sepsis and septic shock: 2012. Crit Care Med 2013;41:580–637.
  3. Russell JA. Management of sepsis. N Engl J Med 2006;355:699–713.
  4. Dombrovskiy VY, Martin AA, Sunderram J, Paz HL. Rapid increase in hospitalization and mortality rates for severe sepsis in the United States: a trend analysis from 1993 to 2003. Crit Care Med 2007;35: 1244-1250.
  5. Rivers E, Nguyen B, Havstad S, Ressler J, Muzzin A, Knoblich B, et al. Early goal-directed therapy in the treatment of severe sepsis and septic shock. N Engl J Med. 2001;345(19):1368–77.
  6. Process Investigators. Yealy DM, Kellum JA, Huang DT, Barnato AE, Weissfeld LA, et al. A randomized trial of protocol-based care for early septic shock. N Engl J Med. 2014;370(18):1683–93.
  7. ARISE Investigators, Anzics Clinical Trials Group. Peake SL, Delaney A, Bailey M, Bellomo R, Cameron PA, et al. Goal-directed resuscitation for patients with early septic shock. N Engl J Med. 2014;371(16):1496–506. doi: 10.1056/NEJMoa1404380.
  8. Mouncey PR, Osborn TM, Power GS, Harrison DA, Sadique MZ, Grieve RD, et al. Trial of early, goal-directed resuscitation for septic shock. N Engl J Med. 2015;372(14):1301–11.
  9. Nguyen HB, Jaehne AK, Jayaprakash N, et al. Early goal-directed therapy in severe sepsis and septic shock: insights and comparisons to ProCESS, ProMISe, and ARISE. Critical Care. 2016;20:160.
  10. Remick DG. Pathophysiology of Sepsis. Am J Pathol. 2007 May;170(5): 1435-1444.
  11. Annane D, Bellissant E, Bollaert PE, et al. Corticosteroids in the treatment of severe sepsis and septic shock in adults: a systematic review. JAMA 2009; 301:2362.
  12. Minneci PC, Deans KJ, Eichacker PQ, Natanson C. The effects of steroids during sepsis depend on dose and severity of illness: an updated meta-analysis. Clin Microbiol Infect 2009; 15:308.
  13. Minneci PC, Deans KJ, Natanson C. Corticosteroid therapy for severe sepsis and septic shock. JAMA 2009; 302:1643; author reply 1644.
  14. Sligl WI, Milner DA Jr, Sundar S, et al. Safety and efficacy of corticosteroids for the treatment of septic shock: A systematic review and meta-analysis. Clin Infect Dis 2009; 49:93.
  15. Annane D, Bellissant E, Bollaert PE, et al. Corticosteroids for treating sepsis. Cochrane Database Syst Rev 2015; :CD002243.
  16. Lamberts SW, Bruining HA, de Jong FH. Corticosteroid therapy in severe illness. N Engl J Med 1997; 337:1285.
  17. Cooper MS, Stewart PM. Corticosteroid insufficiency in acutely ill patients. N Engl J Med 2003; 348:727.
  18. Newsome HH, Rose JC. The response of human adrenocorticotrophic hormone and growth hormone to surgical stress. J Clin Endocrinol Metab 1971; 33:481.
  19. Hume DM, Bell CC, Bartter F. Direct measurement of adrenal secretion during operative trauma and convalescence. Surgery 1962; 52:174.
  20. Boonen E, Vervenne H, Meersseman P, et al. Reduced cortisol metabolism during critical illness. N Engl J Med 2013; 368:1477.
  21. Vadas P, Pruzanski W. Plasma cortisol levels in patients with septic shock. Crit Care Med 1991; 19:300.
  22. Beishuizen A, Thijs LG, Vermes I. Patterns of corticosteroid-binding globulin and the free cortisol index during septic shock and multitrauma. Intensive Care Med 2001; 27:1584.
  23. Hammond GL, Smith CL, Paterson NA, Sibbald WJ. A role for corticosteroid-binding globulin in delivery of cortisol to activated neutrophils. J Clin Endocrinol Metab 1990; 71:34.
  24. Mesotten D, Vanhorebeek I, Van den Berghe G. The altered adrenal axis and treatment with glucocorticoids during critical illness. Nat Clin Pract Endocrinol Metab 2008;4:496–505.
  25. Marik PE, Pastores SM, Annane D, Meduri GU, Sprung CL, Arlt W, Keh D, Briegel J, Beishuizen A, Dimopoulou I, et al. Recommendations for the diagnosis and management of corticosteroid insufficiency in critically ill adult patients: consensus statements from an international task force by the American College of Critical Care Medicine. Crit Care Med 2008;36:1937–1949.
  26. Balk RA. Steroids for septic shock: back from the dead? (Pro). Chest 2003;123:490S–499S.
  27. McGee S, Hirschmann J. Use of corticosteroids in treating infectious diseases. Arch Intern Med 2008;168:1034–1046.
  28. Schumer W. Steroids in the treatment of clinical septic shock. Ann Surg 1976; 184:333.
  29. Shine KI, Kuhn M, Young LS, Tillisch JH. Aspects of the management of shock. Ann Intern Med 1980; 93:723.
  30. Spink WW. ACTH and adrenocorticosteroids as therapeutic adjuncts in infectious diseases. N Engl J Med 1957; 257:1031.
  31. Wagner HN Jr, Bennett IL Jr, Lasagna L, et al. The effect of hydrocortisone upon the course of pneumococcal pneumonia treated with penicillin. Bull Johns Hopkins Hosp 1956; 98:197.
  32. Kass EH. Adrenocorticosteroids and the management of infectious diseases. AMA Arch Intern Med 1958; 102:1.
  33. Bennett, IL Jr, Finland, M, Hamburger, M. The effectiveness of hydrocortisone in the management of severe infections. JAMA 1963; 183:462.
  34. Bone RC, Fisher CJ Jr, Clemmer TP, Slotman GJ, Metz CA, Balk RA. A controlled clinical trial of high-dose methylprednisolone in the treatment of severe sepsis and septic shock. N Engl J Med 1987;317: 653–658.
  35. Veterans Administration Systemic Sepsis Cooperative Study Group. Effect of high-dose glucocorticoid therapy on mortality in patients with clinical signs of systemic sepsis. N Engl J Med 1987;317:659–665.
  36. Sprung CL, Caralis PV, Marcial EH, Pierce M, Gelbard MA, Long WM, Duncan RC, Tendler MD, Karpf M. The effects of high-dose corticosteroids in patients with septic shock: a prospective, controlled study. N Engl J Med 1984;311:1137–1143.
  37. Cronin L, Cook DJ, Carlet J, Heyland DK, King D, Lansang MA, Fisher CJ Jr. Corticosteroid treatment for sepsis: a critical appraisal and meta-analysis of the literature. Crit Care Med 1995;23:1430– 1439.
  38. Annane D, Sebille V, Charpentier C, Bollaert PE, Francois B, Korach JM, Capellier G, Cohen Y, Azoulay E, Troche G, et al. Effect of treatment with low doses of hydrocortisone and fludrocortisones on mortality in patients with septic shock. JAMA 2002;288:862–871.
  39. Oppert M, Schindler R, Husung C, Offermann K, Graf KJ, Boenisch O, Barckow D, Frei U, Eckardt KU. Low-dose hydrocortisone improves shock reversal and reduces cytokine levels in early hyperdynamic septic shock. Crit Care Med 2005;33:2457–2464.
  40. Moran JL, Graham PL, Rockliff S, Bersten AD. Updating the evidence for the role of corticosteroids in severe sepsis and septic shock: a Bayesian meta-analytic perspective. Crit Care 2010;14:R134.
  41. Minneci PC, Deans KJ, Banks SM, Eichacker PQ, Natanson C. Meta-analysis: the effect of steroids on survival and shock during sepsis depends on the dose. Ann Intern Med 2004;141:47–56.
  42. Keh D, Sprung CL. Use of corticosteroid therapy in patients with sepsis and septic shock: an evidence-based review. Crit Care Med 2004;32: S527–S533.
  43. Sprung CL, Annane D, Keh D, Moreno R, Singer M, Freivogel K, Weiss Y, Benbenishty J, Kalenka A, Forst H, et al. Hydrocortisone therapy for patients with septic shock. N Engl J Med 2008;358:111–124.
  44. Freivogel K, Weiss Y, Benbenishty J, Kalenka A, Forst H, et al. Hydrocortisone therapy for patients with septic shock. N Engl J Med 2008;358:111–124.
  45. Wang C, Sun J, Zheng J, Guo L, Ma H, Zhang Y, Zhang F, Li E. Low-dose hydrocortisone therapy attenuates septic shock in adult patients but does not reduce 28-day mortality: a meta-analysis of randomized controlled trials. Anesth Analg. 2014 Feb;118(2):346-57.
  46. Sherwin RL, Garcia AJ, Bilkovski R. Do low-dose corticosteroids improve mortality or shock reversal in patients with septic shock? A systematic review and position statement prepared for the American Academy of Emergency Medicine. J Emerg Med. 2012 Jul;43(1):7-12.
  47. Patel GP, Balk RA. Systemic steroids in severe sepsis and septic shock. Am J Respir Crit Care Med
2012;185(2):133-139.
  48. Stanbury R, Graham E. Systemic corticosteroid therapy—side effects and their management. The British Journal of Ophthalmology 1998;82(6):704-708.
  49. Melby JC, Spink WW. Comparative studies on adrenal cortical function and cortisol metabolism in healthy adults and in patients with shock due to infection. J Clin Invest 1958; 37:1791.
  50. Bouachour G, Roy PM, Guiraud MP. The repetitive short corticotropin stimulation test in patients with septic shock. Ann Intern Med 1995; 123:962.
  51. Sibbald WJ, Short A, Cohen MP, Wilson RF. Variations in adrenocortical responsiveness during severe bacterial infections. Unrecognized adrenocortical insufficiency in severe bacterial infections. Ann Surg 1977; 186:29.
  52. Schein RM, Sprung CL, Marcial E, et al. Plasma cortisol levels in patients with septic shock. Crit Care Med 1990; 18:259.
  53. Hamrahian AH, Oseni TS, Arafah BM. Measurements of serum free cortisol in critically ill patients. N Engl J Med 2004; 350:1629.
  54. Moran JL, Chapman MJ, O’Fathartaigh MS, et al. Hypocortisolaemia and adrenocortical responsiveness at onset of septic shock. Intensive Care Med 1994; 20:489.
  55. Rothwell PM, Udwadia ZF, Lawler PG. Cortisol response to corticotropin and survival in septic shock. Lancet 1991; 337:582.
  56. Marik PE, Zaloga GP. Adrenal insufficiency during septic shock. Crit Care Med 2003; 31:141.
  57. Siraux V, De Backer D, Yalavatti G, et al. Relative adrenal insufficiency in patients with septic shock: comparison of low-dose and conventional corticotropin tests. Crit Care Med 2005; 33:2479.
  58. Venkatesh B, Mortimer RH, Couchman B, Hall J. Evaluation of random plasma cortisol and the low dose corticotropin test as indicators of adrenal secretory capacity in critically ill patients: a prospective study. Anaesth Intensive Care 2005; 33:201.
  59. Loisa P, Uusaro A, Ruokonen E. A single adrenocorticotropic hormone stimulation test does not reveal adrenal insufficiency in septic shock. Anesth Analg 2005; 101:1792.
  60. Briegel J, Sprung CL, Annane D, et al. Multicenter comparison of cortisol as measured by different methods in samples of patients with septic shock. Intensive Care Med 2009; 35:2151.
  61. The COIITSS Study Investigators. Corticosteroid treatment and intensive insulin therapy for septic shock in adults: a randomized con- trolled trial. JAMA 2010;303:341–348.
  62. Venkatesh B, Myburgh J, Finfer S, Webb SA, Cohen J, Bellomo R, McArthur C, Joyce CJ, Rajbhandari D, Glass P, Harward M; ANZICS CTG investigators. The ADRENAL study protocol: adjunctive corticosteroid treatment in critically ill patients with septic shock. Crit Care Resusc. 2013 Jun;15(2):83-8.

Chest Pain Controversies: Coronary CTA Use (Part 2)

Authors: Brit Long, MD (@long_brit, EM Attending Physician at SAUSHEC, USAF) and Alex Koyfman, MD (@EMHighAK, EM Attending Physician, UTSW Medical Center / Parkland Memorial Hospital) // Edited by: Jamie Santistevan, MD (@Jamie_Rae_EMdoc, Admin and Quality Fellow at UW, Madison, WI)

A 53-year-old female presents with 5 hours of chest pain and diffuse weakness. She denies dyspnea, nausea/vomiting, and diaphoresis. Her vital signs, ECG, chest X-ray, and initial labs are completely normal, including troponin and TSH. You have low suspicion of PE, dissection, and other life-threatening diseases. Your center excels with coronary computed tomography angiogram (CCTA). Should you use this modality?

This is the second of a two-part series evaluating chest pain controversies in the ED. The American Heart Association (AHA) supports noninvasive cardiac imaging for further evaluation before or within 72 hours of discharge, which may consist of stress testing, CCTA, or no further testing at all.1 As discussed previously, a nonischemic ECG with negative cardiac biomarkers at 0 hr and 3 hr is associated with low risk of major cardiac adverse event (MACE).2,3 This post will examine the use of CCTA in the ED. Are there benefits? What are the adverse effects? 

Coronary computed tomography angiogram (CCTA)

CCTA has risen to the forefront of chest pain evaluation, providing an anatomical evaluation of coronary artery vasculature. This means that the test is asking one question: is there disease within the coronary arteries? It is important to note that unlike coronary angiogram, CCTA is unable to evaluate coronary blood flow.4-7 However, this test does have the potential to provide a safe, noninvasive measure that allows for a better means to diagnose CAD when compared to history, physical exam, ECG, and biomarkers.4-7

Current Guidelines

The American College of Cardiology Foundation (ACCF)/American Heart Association (AHA) and the European Society of Cardiology (ESC) guidelines list CCTA for use in patients with low or intermediate risk.4,5

Guideline Use of CCTA
ACCF/AHA – Low to intermediate risk patients, exercise capable: Class III, level of evidence C for patients with interpretable ECG. For patients with uninterpretable ECG, Class IIb, level of evidence B for CCTA.

Low to intermediate risk patients, exercise incapable: Class IIa, level of evidence C for CCTA.

– In patients with symptoms at high risk for disease, CCTA assumes a Class IIb, level of evidence C recommendation. Coronary angiogram possesses a Class I, level of evidence C recommendation.

*High risk categorized as presence of classic cardiovascular risk factors: advanced age, hypertension, diabetes mellitus, smoking, male.

ESC – Class IIa, level of evidence C recommendation for CCTA use in patients with lower range of intermediate risk as alternative to stress imaging or non-conclusive exercise ECG or stress imaging.

*Prerequisite of obtaining good imaging quality.

No role for CCTA in symptomatic patients with high pretest probability of disease.

Table 1: Current guidelines for the use of CCTA

The evidence surrounding CCTA 

The evidence for CCTA has shown a low rate of ACS/AMI within 30 days of testing, as well as decreased ED length of stay (LOS).4-10

In 2001, de Filippi et al. randomized 248 patients with normal ECG, negative biomarkers, and ages 20-65 years old to CCTA or exercise testing.8 Positive CCTA was defined by stenosis greater than 50%. Patients with negative CCTA had fewer returns (decreased by 20%) and hospital admissions (3% versus 16%) than patients with negative stress tests. The study revealed no death or MI in both groups at one year.8

The 2012 ACRIN-PA trial randomized 1,370 patients with TIMI score 0-2, ECG without ischemia, and negative first biomarker to CCTA versus standard stress test.9,11 Approximately 50% of patients in CCTA could be discharged, versus 22.7% in the stress arm, decreasing ED LOS.9

The ROMICAT-II trial evaluated CCTA and found that no coronary disease on imaging effectively ruled out ACS. However, if the CT revealed stenosis >/= 50%, sensitivity was reduced to 78.4% for ACS.12 In this population,  length of stay was 7.6 hours in the CCTA group, with a rate of ED discharge 47% in the CCTA group versus 12% in the standard evaluation arm. No difference in the rate of adverse cardiovascular events between groups was found.12

Chang et al. evaluated 32 patients who underwent repeat CCTA imaging at two years after their first imaging evaluation. No patient with less than the 50% stenosis threshold demonstrated > 50% stenosis on second imaging.13

Four large trials randomized low-risk patients to standard workup with stress testing or CCTA following ED evaluation with negative ECG and troponin.9,14-16 These studies in addition to a meta-analysis by Hulten et al. suggest decreased ED LOS, with negative predictive values approaching 99% with CCTA.17 However, no difference in MACE is found based on these large studies.9,14-17

CCTA provides sensitivities ranging from 81% to 99%, specificity 64% to 93%, positive predictive value (PPV) 64% to 92%, and negative predictive value (NPV) 83% to 99%.17-21 Obtaining these results requires an experienced reader and optimal imaging quality. A study in Canada found high variability in diagnostic capability and accuracy across four centers, questioning reproducibility when not interpreted by an experienced radiologist.21 Results demonstrate sensitivity 50% to 93%, specificity 92% to 100%, PPV 85% to 100%, and NPV 43% to 95%.21 Fractional flow reserve assessment with CCTA is a newer modality, with sensitivity 84% to 94% and NPV 72% to 80%.20-23

PROMISE

Two recent large studies have evaluated the use of CCTA in patients with chest pain. The PROMISE study randomized 10,003 patients to standard noninvasive testing or CCTA.24 This study recruited patients from outpatient settings, rather than ED, with new onset chest pain and negative biomarkers and ECG changes. No difference in death, MI, major procedural complications, or hospitalization for unstable angina between the CCTA and standard groups (3.3% versus 3.0%) was found. Patients in the CCTA group underwent more testing and intervention, 12.2% versus 8.1% for catheterization. An overall low mortality rate, 1.5%, and low rate of MI, 0.7%, were found in the population studied.24

SCOT-HEART

The SCOT-HEART trial enrolled 4,146 patients in Scotland, comparing exercise stress test versus evaluation with CCTA.25 Over 85% of patients underwent stress testing. After initial patient assessment, the physician estimated baseline risk of CAD and recommended further testing. Patients were then randomized to CCTA or standard testing only. After 6 weeks, physicians again estimated risk of CAD based on study results. In this trial, CCTA improved physician confidence in diagnosis of CAD and angina, and more patients were diagnosed with CAD in the CCTA group (23% versus 11%). This lead to more cardiac catheterizations. However, the rate of adverse cardiovascular outcomes during the follow up period of 1.7 years was not statistically different, 1.3% versus 2.0%. Patient outcomes were not affected, though physicians felt more comfortable.25

CCTA has repeatedly demonstrated the ability to decrease ED LOS. The majority of these studies incorporate low risk patients, who, with negative ECG and biomarkers, have a risk of less than 1%.2,3,26 CCTA is associated with increased rate of invasive angiography and downstream testing. The meta-analysis by Hulten et al. revealed more downstream testing, including invasive angiography.17

Muhlestein et al. evaluated close to 900 patients with diabetes type I and II, using CCTA for screening of CAD.27 Patients in the CCTA group underwent more catheterizations (13.3% versus 5.1%), more percutaneous interventions (6.0% versus 1.8%), and more bypass operations (2.9% versus 1.3%), with no change in adverse cardiac events.27 Given the increased rate of invasive testing without decreasing adverse events, use of CCTA in low risk patients is questionable.26

What is identified on CCTA?

CCTA detects coronary artery calcium and the degree of obstruction to the artery lumen. Non-obstructive CAD is that which causes <50% arterial stenosis, whereas stenosis of 50% or more defines significant CAD. Calcium plaques can be further characterized based on visual appearance and are considered at high risk for causing thrombosis if any of the following features are present: spotty calcium, remodeling of vasculature, low Housfield Units attenuation, large plaque volume and the napkin-ring sign.12 These radiographic features are based on histologic features of plaques that demonstrate high risk for rupture such as the presence of a necrotic, lipid-rich core, a thin-cap fiberatheroma and vascular remodeling.

napkin-ring

Figure 1: Cross-sectional CT showing coronary plaque with napkin-ring sign.37 a). Non-enhanced image b). Contrast-enhanced image c). Histopathology showing thin-cap fiberoatheroma with a necrotic core*.

Patient selection for CCTA

Patient selection to undergo CCTA is key for optimal imaging. Morbidly obese patients present challenges due to chest wall thickness, which interferes with imaging quality. Patients with known disease, heavy coronary calcifications, and prior coronary revascularization do not benefit. Studies demonstrate high risk patients should undergo angiogram rather than CCTA, which has better assessment of real-time coronary flow, presence of thrombotic material, and collateral circulation.28 Control of heart rate and rhythm is essential, as direct correlation exists with heart rate and ability to evaluate vasculature.29 Over 95% of coronary vasculature is evaluable with a heart rate less than 60 bpm. This decreases to 80% to 90% with rates of 60-65 bpm. As rates approach 70-80 bpm, 70% of the vasculature is evaluable.29 Patients with irregular rhythm, frequent premature atrial or ventricular ectopy, and uncontrolled tachycardia cannot be evaluated.29

Complications of CCTA

CCTA is associated increased radiation exposure, though this has decreased with improved technology. A 320-slice detector reduces radiation to 2-6 mSv.29-34 Despite this, cumulative radiation exposure increases with CCTA use due to increased downstream testing. Chronic kidney disease also warrants caution, as this test can lead to contrast nephropathy.35

Utility of CCTA

CCTA likely causes more harm than benefit in low risk patients, as it can lead to a greater number of false-positive results and further testing and increased radiation exposure.7,26  Utility of CCTA  exists for patients who may have difficulty obtaining further testing or lack of follow-up.4-8 A patient with no disease found on CCTA possesses an extremely low risk of ACS (less than 1%) and these patients can be safely discharged. No disease is found in one third to one half of low to intermediate risk patients.17 If follow-up is in place, CCTA benefit is controversial.7,17,26

If CAD of >50% stenosis is present or if there are high risk plaque features at any degree of stenosis, the patient may require aggressive medical management and should be admitted for further testing with stress test or angiography. In these cases, decision-making with a cardiologist about recommended medical or invasive management is recommended. If any degree of CAD is detected, these patients may also benefit from cardiology consult as further management should include shared decision-making with consideration of the risks and benefits of therapies and patient preferences.

Patients with intermediate risk based on history and other comorbidities may be candidates for further risk stratification with CCTA, as no disease on imaging lowers the risk of MACE.36 Further studies on the utility of CCTA for intermediate risk patients is required. Use in high risk patients should be avoided, as coronary artery disease is likely to be present on CCTA.7,26,36

Summary

– Missed ACS is a concern for patients and emergency providers. Nonischemic ECG and negative biomarker at 0 and 3 hours reduces risk of MACE to less than 1%.

– Stress testing and CCTA are commonly used for further evaluation of these patients, but their ability to further risk stratify low risk patients further is controversial.

– Use of CCTA has increased, with the goal to evaluate anatomical coronary artery disease.

– CCTA is associated with decreased ED LOS. However, CCTA is also associated with further downstream testing, with no evidence of improved outcome in low risk patients.

Intermediate risk patients, or those with difficulty obtaining follow up, may benefit from CCTA, though further studies are required in this patient subset.

References/Further Reading

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  2. Pope JH, Aufderheide TP, Ruthazer R, Woolard RH, Feldman JA, Beshansky JR, et al. Missed diagnoses of acute cardiac ischemia in the emergency department. N Engl J Med 2000; 342:1163–70.
  3. Weinstock MB, Weingart S, Orth F, VanFossen D, Kaide C, Anderson J, Newman DH. Risk for Clinically Relevant Adverse Cardiac Events in Patients With Chest Pain at Hospital Admission. JAMA Intern Med 2015 Jul;175(7):1207-12.
  4. Montalescot G, Sechtem U, Achenbach S, Andreotti F, Arden C, Budaj A, et al. 2013 ESC guidelines on the management of stable coronary artery disease: the Task Force on the management of stable coronary artery disease of the European Society of Cardiology. Eur Heart J 2013;34:2949–3003.
  5. Fihn SD, Gardin JM, Abrams J, Berra K, Blankenship JC, Dallas AP, et al; American College of Cardiology Foundation/American Heart Association Task Force. 2012 ACCF/AHA/ACP/AATS/PCnA/SCAI/STS guideline for the diagnosis and management of patients with stable ischemic heart disease: a report of the American College of Cardiology Foundation/American Heart Association task force on practice guidelines, and the American College of Physicians, American Association for Thoracic Surgery, Preventive Cardiovascular nurses Association, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. Circulation 2012;126:e354–e471.
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