Echo Aids Diagnosis, Risk Prediction in Severe COVID-19

Echocardiography can identify a range of cardiac abnormalities in COVID-19 patients who have biomarkers indicative of myocardial injury, a new study shows. Importantly, the combination of both abnormalities on transthoracic echo (TTE) and elevated troponin is associated with an increased risk of mortality compared with biomarker evidence of cardiac injury alone.

Lead author on the study, Gennaro Giustino, MD (Icahn School of Medicine at Mount Sinai, New York, NY), stressed that the retrospective series was highly selected, looking only at SARS-CoV-2-positive patients for whom the treating physicians had ordered an echocardiogram—usually because of troponin elevation. But the results underscore the range of echocardiographic findings seen in severe COVID-19, offering avenues to improve care.

“Understanding the substrate gives you information on whether you need further diagnostic workup or if you need to adopt specific treatments,” he said. “If you have wall motion abnormalities, that can be secondary to thrombosis in the epicardial coronary arteries or in the microcirculation. If you have global dysfunction, that would be, perhaps, myocarditis. If you have right ventricular dysfunction, that can be very bad respiratory failure or pulmonary embolism. All that starts to give you some sense of what is happening pathophysiologically to a patient."

Giustino and colleagues published their findings online today in the Journal of the American College of Cardiology.

Exploring Injury

The retrospective study involved 305 patients (67% men) with confirmed COVID-19 who got a TTE and an ECG during their hospital admission at one of seven centers in New York City or Milan between March 5 and May 2, 2020. Giustino stressed that these were patients whose cardiac symptoms or biomarker results prompted additional cardiac testing and that the study by no means captured all patients presenting to these hospitals, all of them hit hard in the early months of the pandemic.

Overall, 62.3% of patients were found to have had myocardial injury, defined as a cardiac troponin elevation at any time during admission. This group was more likely to also have electrocardiographic changes and increased inflammatory markers, as well as cardiac abnormalities on echo (found in 63.2%), than patients who didn’t have myocardial injury (21.7%). These included regional LV wall motion abnormalities, global LV dysfunction, grade II or III diastolic dysfunction, RV dysfunction, and pericardial effusions. Left ventricular volumes, LV wall thickness, and left atrial volumes were all more likely to be greater in patients with biomarker evidence of myocardial injury.

Seeing these cardiac changes on echo should trigger warning bells, Giustino and colleagues write. “Compared with patients without myocardial injury, those with myocardial injury had higher rates of in-hospital death (26.8% vs 5.2%; P < 0.0001), intensive care unit admission, mechanical ventilation, acute respiratory distress syndrome, acute kidney injury, and cardiocirculatory shock.”

An Expanding Role

To TCTMD, Giustino stressed that any hint of cardiac involvement means an echo should be ordered, if feasible and safe for healthcare providers.

“It may be helpful for two reasons,” he said, “both for risk stratification, because we've shown that these patients have worse prognosis despite the fact that we are talking about a very selective cohort, and for patient management. . . . Particularly when everyone was saying, oh, we saw a reduction in STEMIs, where did all the MIs go? It may be that some were missed because we were underdiagnosing them, because we were not performing the right tests.”

Their series was restricted to patients who underwent full TTE exams; patients screened only with point-of-care echo were excluded from the analysis. But as Carl “Chip” Lavie, MD (John Ochsner Heart and Vascular Institute, New Orleans, LA), and colleagues point out in an accompanying editorial, other investigators have made the case for handheld echo “as a potential fast, efficient, and cost-effective echocardiographic screening modality” in patients testing positive for COVID-19.

Lavie and colleagues point out that current American College of Cardiology recommendations stipulate that cardiac troponin should be measured when a diagnosis of acute MI is suspected in the setting of COVID-19. “This indication seems somehow inadequate according to the information collected by Giustino et al, whereby there is now evidence that troponin-positive COVID-19 patients may benefit from routine TTE, which would allow practitioners to garner useful prognostic information and to establish specific therapeutic options in patients with cardiac injury,” the editorialists write.

Indeed, Giustino said his center now is routinely measuring troponin in all emergency department patients.

In the early months of the pandemic, an Israeli team headed by Yan Topilsky, MD (Tel Aviv Medical Center, Israel), published one of the first papers describing echocardiographic features of COVID-19 in 32 consecutive patients. Commenting on the current analysis, Topilsky called the paper “important and interesting,” noting that it confirms the major forms of cardiac injury documented in their smaller series, with the disadvantages of being retrospective and confined to patients with an indication for TTE.

“Thus, it does not advance our knowledge about cardiac injury patterns and the predictive role of TTE in other (more common) patients with COVID 19, with milder forms of disease,” he said in an email. Nevertheless, the paper “clarifies again that it is ‘worth’ getting an echo in a person with other signs of myocardial injury. It will be interesting to follow up on the role of TTE in patients with milder forms of COVID 19 infection, with or without laboratory signs of myocardial injury,” something his team is currently working on.

Giustino, too, said he and co-investigators plan to follow their cohort to see whether the kinds of injuries seen acutely have lasting implications for the heart.