Hidden systolic dysfunction of the right ventricle in patients with increased pulmonary vascular resistance 3 months after COVID-19 pneumonia.

Aim      To study the relationship of echocardiographic right ventricular (RV) structural and functional parameters and indexes of pulmonary vascular resistance (PVR) in patients 3 months after COVID-19 pneumonia.Material and methods  This cross-sectional, observational study included 96 patients aged 46.7±15.2 years. The inclusion criteria were documented diagnosis of COVID-19-associated pneumonia and patient's willing to participate in the observation. Patients were examined upon hospitalization and during the control visit (at 3 months after discharge from the hospital). Images and video loops were processed, including the assessment of myocardial longitudinal strain (LS) by speckle tracking, according to the effective guidelines. The equation [tricuspid regurgitation velocity/ time-velocity integral of the RV outflow tract × 10 + 0.16] was used to determine PRV. Patients were divided into group 1 (n=31) with increased PRV ≥1.5 Wood units and group 2 (n=65) with PRV <1.5 Wood units.Results At baseline, groups did not differ in main clinical functional characteristics, including severity of lung damage by computed tomography (32.7±22.1 and 36.5±20.4 %, respectively. р=0.418). Echocardiographic linear, planimetric and volumetric parameters did not significantly differ between the groups. In group 1 at the control visit, endocardial LS of the RV free wall (FW) (-19.3 [-17.9; -25.8] %) was significantly lower (р=0.048) than in group 2 (-23.4 [-19.8; -27.8] %), and systolic pulmonary artery pressure (sPAP) according to C. Otto (32.0 [26.0; 35.0] mm Hg and 23.0 [20.0; 28.0] mm Hg) was significantly higher than in group 2 (р<0.001). According to the logistic regression, only endocardial RV FW LS (odds ratio, OR, 0.859; 95 % confidence interval, CI, 0.746-0.989; р=0.034) and sPAP (OR, 1.248; 95 % CI, 1.108-1405; р<0.001) were independently related with the increase in PVR. Spearman correlation analysis detected a moderate relationship between PVR and mean PAP according to G. Mahan (r=0.516; p=0.003) and between PVR and the index of right heart chamber functional coupling with the PA system (r=-0.509; p=0.007) in group 1 at the control visit.Conclusion      In patients 3 months after COVID-19 pneumonia, hidden RV systolic dysfunction defined as depressed endocardial RV FW LS to -19.3% is associated with increased PVR ≥1.5 Wood units.