Exercise stress echocardiography shows impaired left ventricular function after hospitalization with COVID-19 without overt myocarditis: A pilot study.

Usual clinical testing rarely reveals cardiac abnormalities persisting after hospitalization for COVID. Such testing may overlook residual changes causing increased adverse cardiac events post-discharge. To clarify status post-hospitalization, we related exercise stress echocardiography (ESE) in 15 recovering patients (RP) age 30-63 without myocarditis to matching published data from healthy subjects (HS). RP exercise, average duration 8.2 ± 2.2 SD, was halted by dyspnea or fatigue. RP baselines matched HS except for higher heart rate. At peak stress, RP had significantly lower mean left ventricular (LV) ejection fraction (67% ± 7 vs. 73% ± 5, p < 0.0017) and higher peak early mitral inflow velocity/early mitral annular velocity (E/e', 9.1 ± 2.5 vs. 6.6 ± 2.5, p < 0.006) compared with HS performing equal exercise (8.5 ± 2.6 min). Thus, when stressed, patients without known cardiac impairment showed diminished systolic contractile function and diastolic LV compliance vs. HS. RP peak heart rate was significantly higher (172 ± 18 vs. 153 ± 20); peak systolic blood pressure trended higher (192 ± 31 vs. 178 ± 19). Pulmonary artery systolic pressures among RP remained normal. ESE uniquely identified residual abnormality in cardiac contractile function not evident unstressed, exposing previously unrecognized residual influence of COVID-19. This may reflect autonomic dysfunction, microvascular disease, or diffuse interstitial changes; these results may have implications for clinical management and later prognosis.