In December of 2019, Coronavirus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged, resulting in a global pandemic with 125 million cases worldwide. Few prospective echocardiographic studies have been performed to characterize cardiac manifestations of patients who have recovered from acute COVID-19 infection. There are limited data on the residual echocardiographic findings including strain analysis of post-COVID patients. One aim of our CIHR-funded study is to prospectively phenotype post-COVID patients using conventional echocardiography including strain imaging.
METHODS AND RESULTS
All patients discharged from hospital following acute COVID-19 infection are systematically followed in the Post-COVID-19 Recovery Clinic at Vancouver General Hospital and St. Paul's Hospital. At about 4-12 weeks post diagnosis, patients undergo comprehensive echocardiographic assessment with conventional echocardiography including strain analysis. Left ventricular ejection fraction (LVEF) was assessed by 3D, 2D Biplane Simpson's, or visual estimate. Left ventricular global longitudinal strain (GLS), was measured using a vendor-independent 2D speckle-tracking software (TomTec). A total of 127 patients (53% female, mean age 58 years) were included in our analyses. At baseline, cardiac conditions were present in 58% of the patients (15% coronary artery disease, 4% heart failure, 44% hypertension, 10% atrial fibrillation), while the remainder were free of cardiac conditions. COVID-19 serious complications were present in 79% of the patients (76% pneumonia, 37% ICU admission, 21% intubation, 1% myocarditis). Normal LVEF was seen in 96% of cohort defined in this study as EF≥54%, and 97% had normal RV systolic function. A high proportion (53%) had abnormal LV GLS defined as < 18%. Average LV GLS in septal and inferior segments were lower compared to the rest. In patients without pre-existing cardiac conditions, LVEF was abnormal in only 1.9% but LV GLS was abnormal in 46%.
Most post-COVID patients had normal LVEF at 4-12 weeks post positive test, but over half had abnormal LV GLS. Even when patients with pre-existing cardiac conditions were excluded, 46% had abnormal global strain. There appeared to be a high predilection for septal, and to a lesser extent, inferior wall involvement, giving an appearance of a “C” sign on the bullseye strain map. Further studies are needed to confirm whether these abnormalities are consistently found and to understand the long-term cardiac sequelae of SARS-CoV-2 infection.