Admission ECG abnormalities, elevated cardiac troponins predict higher 30-day mortality in COVID-19

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The combination of myocardial injury with high-sensitivity cardiac troponin T (hs-cTnT) levels ≥ 20 ng/L, plus cardiac conduction perturbations, especially atrial fibrillation or atrial flutter (AF/AFL), upon hospital admission for coronavirus disease 2019 (COVID-19) is associated with “markedly increased” risk for mortality than either diagnostic abnormality alone, according to a study published in the Journal of the American Heart Association.

Timothy J Poterucha, MD, Columbia University Irving Medical Center, New York, New York, and colleagues analyzed 887 patients (aged 64±17 years) admitted with COVID-19 from March 1 to April 3, 2020, at Columbia University Irving Medical Center and New York-Presbyterian Allen Hospital who underwent with 12-lead electrocardiography (ECG) within 2 days of diagnosis. At 30 days follow-up, 556 patients (63%) were living without requiring mechanical ventilation, 123 (14%) were living and required mechanical ventilation, and 203 (23%) had expired. Common comorbidities included hypertension (61%), diabetes mellitus (39%), obesity (35%), chronic kidney disease (17%) and lung disease (16%). Comorbid cardiovascular disease included coronary artery disease (12%), heart failure with reduced ejection fraction (7%), and heart failure with preserved ejection fraction (5%).

ECG findings revealed that 582 (66%) patients had sinus rhythm, 226 (25%) had sinus tachycardia, 40 (5%) had atrial fibrillation, and 6 (1%) had atrial flutter. Meanwhile, ectopic atrial and ventricular beats were present in 67 (8%) and 48 (5%) of patients, respectively. Of the 46 patients with AF/AFL on the presenting ECG, 27 (59%) died, compared with 181 (21%) of the 841 patients with sinus rhythm, ectopic atrial rhythm, or atrially paced rhythm (p<0.001). Meanwhile, ST segment and T wave abnormalities were assessed in a total of 812 patients with a QRS duration less than 120 ms, with abnormal ST or T waves observed in 306 (38%) patients.

In an analysis of 830 patients who underwent both an ECG within 2 days of presentation and hs-cTnT testing, the researchers found that the combination of an abnormal ECG and hs-cTnT ≥ 20 ng/L was associated with increased 30-day mortality, with death occurring in 132 of 267 patients (49%) with both abnormal features versus 15 of 264 (6%) of those with a normal ECG and hs-cTnT < 20 ng/L (p<0.001).

Multivariable analysis incorporating age, comorbidities, AF/AFL, QRS abnormalities, ST-T wave changes, and initial hs-cTnT ≥ 20 ng/L, showed that increased age (hazard ratio [HR] 1.04/year), elevated hs-cTnT (HR 4.57), AF/AFL (HR 2.07), a history of coronary artery disease (HR 1.56) and active cancer (HR 1.87) were associated with increased mortality.

“The associations between elevated troponin and AF/AFL with adverse outcomes have several possible explanations,” the authors wrote. “First, direct COVID-19 myocarditis may occur, and case studies have been published of patients with clinically diagnosed COVID-19-related myocarditis or myopericarditis. Secondly, the systemic coagulopathy that has been documented in severe COVID-19 infection could lead to microvascular or epicardial coronary thrombosis. Thirdly, COVID-19 may result in a stress cardiomyopathy and cardiac injury from systemic inflammation, either as an isolated entity or accompanied by multi-system organ failure with hypoxemia and shock. Finally, systemic inflammation can also lead to increased sympathetic activation which may precipitate serious cardiac arrhythmias such as AF/AFL.”

The authors noted that it is possible that the troponin and AF/AFL seen in this study may be surrogates of more advanced age and pre-existing cardiovascular comorbidities, so they attempted to control for a number of important comorbidities and age in addition to ECG categorization and hs-cTnT using Cox proportional hazards models. “After multivariable adjustment, we found that elevated hs-cTnT and AF/AFL remained significantly associated with adverse outcomes. As a result, these tests provide important prognostic information even after controlling for baseline comorbidities and clearly identify a high-risk group of COVID-19 patients who warrant aggressive monitoring and treatment,” the authors said.

“Cardiac injury in the setting of COVID-19 can lead to myocardial injury and rhythm disturbances, and the findings of both an elevated cardiac troponin and atrial arrhythmias on admission portends an ominous prognosis. Further study is needed to clarify the mechanisms of cardiovascular involvement in COVID-19,” the authors concluded.