Biventricular dysfunction and lung congestion in post-COVID patients: a speckle tracking and stress lung echocardiography analysis

Abstract

Abstract Background Cardiovascular abnormalities have been observed in half of all COVID-19 patients in the acute phase of the infection. Additionally, 10-35% of these patients have various long-term symptoms diagnosed with post-acute sequelae of COVID-19 (PASC). Aim of this study was to evaluate the role of exercise stress echocardiography (ESE) with an integrated approach, inclusive of Speckle-Tracking Echocardiography (STE) with Myocardial Work (MW) analysis in the evaluation of patients after COVID infection. Methods We prospectively recruited a population of 370 post-COVID 19 patients (Group 1) (225 males; 55.8 ±8.3 years), and of 250 age- and sex-comparable healthy controls (Group 2). In Standard Doppler echocardiography, STE and MW analyses and lung ultrasound at rest and at peak supine-bicycle ESE were performed. Results Left ventricular (LV) wall thickness, diameters and mass index were comparable between the two groups. Both LV ejection fraction (EF) and right ventricular (RV) functional indexes (TAPSE and Tissue Doppler S’ wave) at rest did not show differences between the two groups. Conversely, baseline LV GLS (-16.2±2.8 vs. –20.4±3.3 %; p<0.01), MW efficiency (88.8±3.2 vs. 93.2±3.3 %; p<0.001), and RV strain (-16.4±2.8 vs. –20.4±4.3 %; p<0.01), were significantly reduced in Group 1. Also pulmonary artery systolic pressures (PASP) (33.5±3.8 vs. 24.6±3.1 mmHg; p<0.001), and LV E/e’ ratio were significantly increased in COVID group, while B-lines ( ≥ 2) at rest were found in 25.3% of Group 1 and 5.1% of Group 2 (p < 0.001). During effort, COVID patients showed reduced exercise time and exercise capacity (<0.001). Values of LVEF, RV strain and LV GLS (all with p value <0.01) and MWE (p<0001) were much lower in COVID patients when compared to Group 2. Additionally, COVID patients showed at peak effort an increased LV E/e’ ratio, pulmonary pressures and B-lines by lung ultrasound (all p <0.001). Multivariable analysis detected independent associations of baseline GLS and MWE with maximal workload (watts reached), LV E/e’ ratio and B-lines during effort (p<0.001), stronger than the association of LVEF with the same functional parameters (p<0.01). What’s more, RV strain (p<0.001) was significantly associated with PASP levels at peak effort. Conclusions In post-COVID patients, biventricular involvement with impairment of LV and RV systolic function is frequent, missed by conventional indices such as EF or TAPSE, and detected by more sensitive STE indices such as LV-GLS, ME, and RV-strain. These alterations are functionally significant and associated with shorter exercise -time, more pulmonary hypertension, and greater pulmonary congestion during stress.