What’s the connection between elevated troponins and Covid-19?

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).

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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!

 

What’s the connection between elevated troponins and Covid-19?

Can syncope be related to acute pulmonary embolism in the absence of hemodynamic instability or right ventricular failure?

Although we often think of syncope caused by acute pulmonary embolism (APE) in the setting of submassive or massive APE and right ventricular failure or shock (1,2), less massive APE may potentially cause syncope as well by triggering a vaso-vagal reflex (3).

For sure, a significant association between submassive or massive APE and syncope has been reported (1,2).  More specifically, patients with syncope and APE may be more likely to have systolic blood pressure <90 mmHg, right ventricular dilation and right ventricular hypokinesis (1). Another study reported a higher rate of central embolism (83% vs 43%), right ventricular dysfunction (91% vs 68%) and troponin positivity (80% vs 39%), but not 30 day mortality (2).

In contrast, 1 study found that patients with syncope as a presenting symptom of APE did not show a more serious clinical picture (e.g. shock) than those without syncope (3), while another found EKG signs of acute right ventricle overload in only 25% of patients with syncope (4).  

So while massive APEs may be associated with syncope, they don’t seem to be a prerequisite for this condition.

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References

1.  Omar HR, Mirsaeidi M, Weinstock MB, et al. Syncope on presentation is a surrogate for submassive and massive acute pulmonary embolism. Am J Emerg Med 2018;36:297-300. https://www.ncbi.nlm.nih.gov/pubmed/29146419

2. Altinsoy B, Erboy F, Tanriverdi H, et al. Syncope as a presentation of acute pulmonary embolism. Ther Clin Risk Manag 2016;12:1023-28. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4930221/

3. Castelli R, Tarsia P, Tantardini G et al. Syncope in patients with pulmonary embolism: comparison between patients with syncope as the presenting symptom of pulmonary embolism and patients with pulmonary embolism without syncope. Vascular Medicine 2003;8:257-261. https://journals.sagepub.com/doi/abs/10.1191/1358863x03vm510oa

4. Miniati M, Cenci, Monti S, et al. Clinical presentation of acute pulmonary embolism: survey of 800 cases. PloS One 2012;7:e30891.

 

 

Can syncope be related to acute pulmonary embolism in the absence of hemodynamic instability or right ventricular failure?