Elevated cardiac troponins or myocardial injury (defined as troponin levels above the 99th percentile upper reference range) are not uncommon in Covid-19, having been reported in ~10-30% of hospitalized patient and usually observed in the absence of acute coronary syndrome (ACS) (1-4).
Elevated troponins have been associated with increased risk of in-hospital mortality in Covid-19. The prevalence of elevated troponins among patients who died was 76% compared to 10% among survivors in 1 Chinese study (3). Another study from China found increasing troponin levels over a 22 day period among those who died while troponin levels remained low in those who survived (5).
Risk factors for elevated troponins in Covid-19 include older age, cardiovascular comorbidities (eg, hypertension, coronary heart disease, heart failure), diabetes, chronic obstructive pulmonary disease, chronic renal failure, and the presence of a high inflammatory state, as indicated by elevated inflammatory markers such as C-reactive protein (CRP) (3).
Several mechanisms have been proposed to explain elevated troponins in Covid-19, including cytokine-induced myocardial injury, microangiopathy due to prothrombotic state, myocardial infarction (type I due to plaque rupture or type II due to oxygen supply/demand imbalance), and myocarditis either due to direct viral invasion or indirectly through immune-mediated mechanisms (1,2).
Patients with Covid-19 and modest troponin elevation with rapid fall in the absence of signs or symptoms of ACS, may have type II myocardial infarction due to demand ischemia, particularly in the setting of coronary disease. In contrast, more protracted elevation of troponins associated with high inflammatory markers such as CRP is suggestive of hyperinflammatory myocardial injury (1).
It will be interesting to see if trials of anti-inflammatory agents, such as colchicine and anti-interleukin-I, will have an impact on the troponin levels in Covid-19 patients (1).
Liked this post? Download the app on your smart phone and sign up below to catch future pearls right into your inbox, all for free!
References
1. Cremer PC. SARS-CoV-2 and myocardial injury: few answers, many questions. Clev Clin J Med. Posted April 8, 2020. Doi:10.3949/ccjm.87a.ccc001 https://www.ccjm.org/content/early/2020/05/12/ccjm.87a.ccc001
2. Tersalvi G, Vicenzi M, Calabretta D, et al. Elevated troponin in patients with coronavirus disease 2019:possible mechanisms. J Card Failure 2020; https://pubmed.ncbi.nlm.nih.gov/32315733/
3. Shi S, Qin M, Cai Y, et al. Characteristics and clinical significance of myocardial injury in patients with severe coronavirus disease 2019. Eur Heart J 2020. https://pubmed.ncbi.nlm.nih.gov/32391877/
4. Richardson S, Hirsch JS, Narasimhan M, et al. Presenting characteristics, comorbidities, and outcomes among 5700 patients hospitalized with COVID-19 in the New York City area. JAMA 2020;323:2052-59. https://jamanetwork.com/journals/jama/fullarticle/2765184
5. Zhou F, YU T, Du R, et al. Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. Lancet 2020;395:1054-62. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30566-3/fulltext
Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Massachusetts General Hospital, Harvard Catalyst, Harvard University, its affiliate academic healthcare centers, or its contributors. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!
