Serial Echocardiographic Assessment of Right Ventricular Function and Its Association With Functional Capacity, Dyspnea, and Pulmonary Diffusion in Post-COVID-19 Survivors

Abstract

Background

Survivors of post-COVID-19 may experience persistent functional impairment and late cardiopulmonary sequelae. The right ventricle (RV) is particularly susceptible to injury, and RV free wall longitudinal strain (RVFWLS), measured by 2D speckle-tracking echocardiography (2D-STE), can detect subclinical RV systolic dysfunction.

Objective

To evaluate longitudinal changes in RV systolic function, assessed by RVFWLS, tricuspid annular plane systolic excursion (TAPSE), fractional area change (FAC), and tricuspid annular systolic velocity (S′), and to investigate their associations with functional capacity (30-second sit-to-stand test [30STS]), functional status (Post-COVID-19 Functional Status Scale [PCFS]), dyspnea (modified Medical Research Council [mMRC] scale), and carbon monoxide transfer coefficient (KCO) in post-COVID-19 survivors.

Methods

This observational analysis included participants from a prospective post-COVID-19 cohort evaluated at two follow-up visits (AV1 and AV2), approximately 4 and 13 months after the acute infection. Adults with confirmed SARS-CoV-2 infection and analyzable transthoracic echocardiography using 2D-STE were included. Statistical significance was defined as a two-sided p < 0.05.

Results

A total of 49 patients were included; 55.1% were women, the mean age was 50.7 ± 10.3 years, 63.3% had obesity, 77.6% required intensive care unit admission, and 67.3% underwent invasive mechanical ventilation. Performance on the 30STS improved (10.1 ± 3.3 vs 11.6 ± 3.1 repetitions; p = 0.004), and KCO increased (4.1 ± 0.7 vs 4.3 ± 0.8 mL/min/mmHg/L; p = 0.002), whereas mMRC scores (p = 0.43) and median PCFS scores (p = 0.11) remained unchanged. TAPSE decreased modestly but remained within the normal reference range (2.2 ± 0.3 vs 2.1 ± 0.2 cm; p = 0.03), while RVFWLS, FAC, and S′ showed no significant changes over time. Cross-sectional correlations between RV systolic indices and clinical outcomes were weak and nonsignificant at both AV1 and AV2 (|r| 0.05). Longitudinally, changes in RVFWLS were positively correlated with changes in KCO (r = 0.33; p = 0.05), whereas changes in FAC were inversely correlated with changes in PCFS scores (r = −0.35; p = 0.02).

Conclusios

In this cohort of post-COVID-19 survivors, functional capacity and pulmonary diffusing capacity improved over time, whereas RVFWLS remained persistently reduced without significant longitudinal change. These exploratory findings suggest that RV systolic indices should not be interpreted in isolation as markers of functional limitation during the late post-COVID-19 period and support the use of an integrated, multiparametric approach to patient assessment.