Comprehensive temporal analysis of right ventricular function and pulmonary haemodynamics in mechanically ventilated COVID-19 ARDS patients

Background Cardiac injury is frequently reported in COVID-19 patients, the right ventricle (RV) is mostly affected. We systematically evaluated the cardiac function and longitudinal changes in severe COVID-19 acute respiratory distress syndrome (ARDS) admitted to the intensive care unit (ICU) and assessed the impact on survival. Methods We prospectively performed comprehensive echocardiographic analysis on mechanically ventilated COVID-19 ARDS patients, using 2D/3D echocardiography. We defined left ventricular (LV) systolic dysfunction as ejection fraction (EF) < 40%, or longitudinal strain (LS) > − 18% and right ventricular (RV) dysfunction if two indices among fractional area change (FAC) < 35%, tricuspid annulus systolic plane excursion (TAPSE) < 1.6 cm, RV EF < 44%, RV–LS > − 20% were present. RV afterload was assessed from pulmonary artery systolic pressure (PASP), PASP/Velocity Time Integral in the right ventricular outflow tract (VTI RVOT ) and pulmonary acceleration time (PAcT). TAPSE/PASP assessed the right ventriculoarterial coupling (VAC R ). Results Among 176 patients included, RV dysfunction was common (69%) (RV–EF 41.1 ± 1.3%; RV–FAC 36.6 ± 0.9%, TAPSE 20.4 ± 0.4mm, RV–LS:− 14.4 ± 0.4%), usually accompanied by RV dilatation (RVEDA/LVEDA 0.82 ± 0.02). RV afterload was increased in most of the patients (PASP 33 ± 1.1 mmHg, PAcT 65.3 ± 1.5 ms, PASP/VTI RVOT , 2.29 ± 0.1 mmHg/cm). VAC R was 0.8 ± 0.06 mm/mmHg. LV–EF < 40% was present in 21/176 (11.9%); mean LV–EF 57.8 ± 1.1%. LV–LS (− 13.3 ± 0.3%) revealed a silent LV impairment in 87.5%. A mild pericardial effusion was present in 70(38%) patients, more frequently in non-survivors ( p < 0.05). Survivors presented significant improvements in respiratory physiology during the 10th ICU-day (PaO 2 /FiO 2 , 231.2 ± 11.9 vs 120.2 ± 6.7 mmHg; PaCO 2 , 43.1 ± 1.2 vs 53.9 ± 1.5 mmHg; respiratory system compliance—C RS , 42.6 ± 2.2 vs 27.8 ± 0.9 ml/cmH 2 O, all p < 0.0001). Moreover, survivors presented significant decreases in RV afterload (PASP: 36.1 ± 2.4 to 20.1 ± 3 mmHg, p < 0.0001, PASP/VTI RVOT : 2.5 ± 1.4 to 1.1 ± 0.7, p < 0.0001 PAcT: 61 ± 2.5 to 84.7 ± 2.4 ms, p < 0.0001), associated with RV systolic function improvement (RVEF: 36.5 ± 2.9% to 46.6 ± 2.1%, p = 0.001 and RV–LS: − 13.6 ± 0.7% to − 16.7 ± 0.8%, p = 0.001). In addition, RV dilation subsided in survivors (RVEDA/LVEDA: 0.8 ± 0.05 to 0.6 ± 0.03, p = 0.001). Day-10 C RS correlated with RV afterload (PASP/VTI RVOT , r: 0.535, p < 0.0001) and systolic function (RV–LS, 0.345, p = 0.001). LV–LS during the 10th ICU-day, while ΔRV–LS and ΔPASP/RVOT VTI were associated with survival. Conclusions COVID-19 improvements in RV function, RV afterload and RV–PA coupling at day 10 were associated with respiratory function and survival.