Myocardial injury is significantly associated with fatal outcome of COVID-19, while the prognosis of patients with underlying (CVD) but without myocardial injury is relatively favourable according to a recent study in JAMA Cardiology1.
In this retrospective single-centre case series, the authors analysed consecutive hospitalized patients with COVID-19 at the Seventh Hospital of Wuhan City, China, from January 23, 2020, to February 23, 2020. Cardiac injury was defined as serum levels of troponin T (TnT) above the 99th percentile upper reference limit.
Among 187 patients with confirmed COVID-19, the mean age of the patients was 58.5 (±14.6), and about half were male. Overall, 35.3% had underlying CVD including hypertension, coronary heart disease, and cardiomyopathy, and 27.8% exhibited myocardial injury. Compared with patients with normal TnT levels, patients with myocardial injury were older, with higher proportion of men and had significantly higher rates of comorbidities.
In-hospital mortality was different according to the presence of CVD and myocardial injury. The mortality rate was 7.62% for patients without underlying CVD and normal TnT levels, 13.33% for those with underlying CVD and normal TnT levels. And 37.50% for those without underlying CVD but elevated TnT levels, and 69.44% for those with underlying CVD and elevated TnTs.
The authors also found that TnT levels are significantly associated with levels of C-reactive protein (β = 0.530, P < .001) and N-terminal pro-B-type natriuretic peptide (β = 0.613, P < .001), thus linking myocardial injury to severity of inflammation and ventricular dysfunction. Also dynamic changes in TnT and NT-proBNP were observed, with significantly increased levels during hospitalization in those who ultimately died, but no such dynamic changes were evident in survivors.
Evidence is growing regarding the presence of myocardial injury in coronavirus disease. Huang et al2 reported that 12% of patients with COVID-19 were diagnosed as having acute myocardial injury, manifested mainly by elevated levels of high-sensitive troponin I. From other recent data, among 138 hospitalized patients with COVID-19, 7.2% had acute myocardial injury3. In a recently summarized study in Heart Blog, Shi S et al4 found that approximately 20% of patients had cardiac injury, and as previously reported these patients were older and had more comorbid conditions. However specific information characterizing whether patients with COVID-19 with underlying CVD who develop myocardial injury during hospitalization face greater risk and have worse in-hospital outcomes was lacking. The authors of this study conclude that in this preliminary assessment myocardial injury appears to have a significant association with the fatal outcome of COVID-19, while the prognosis of patients with underlying CVD but without myocardial injury is relatively favourable. Therefore, it seems reasonable to classify patients with COVID-19 according to the presence of underlying CVD and evidence of myocardial injury.
This study is single-centre case series with consecutive patients, it is important to mention that the authors excluded 69 patients because of incomplete data. The results were evaluated in the short term. An association between troponin levels and mortality was observed. The adjusted prognostic effect estimates were not analyzed. This is extremely important considering the differences in the baseline characteristics of patients who had myocardial injury from those who did not. Furthermore, it does not mention whether the events adjudication was blinded to troponin levels.
More studies are needed to evaluate if these patients need different treatment with aggressive strategies. And data from larger populations of multiple centres with long-term observation are warranted to further confirm the prognosis of cardiac injury in COVID-19.
1. Guo T, Fan Y, Chen M, et al. Cardiovascular Implications of Fatal Outcomes of Patients With Coronavirus Disease 2019 (COVID-19). JAMA Cardiol. 2020. Doi: 10.1001/jamacardio.2020.1017.
2. Huang C, Wang Y, Li X, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet. 2020;395(10223):497-506. doi:10.1016/S0140-6736(20)30183-5
3. Wang D, Hu B, Hu C, et al. Clinical characteristics of 138 hospitalized patients with 2019 novel coronavirus-infected pneumonia in Wuhan, China. JAMA. Published February 7, 2020. doi:10.1001/jama.2020.1585
4. Shi S, Qin M, Shen B, Cai Y, Liu T, Yang F, et al. Association of cardiac injury with mortality in hospitalized patients with COVID-19 in Wuhan, China. JAMA Cardiol. 2020. Doi:10.1001/jamacardio.2020.0950