The Clinical Role of Right Ventricle Changes in COVID-19 Respiratory Failure Depends on Disease Severity.

To The Editor:

We read with great interest the paper by Paternoster et al. addressing the prognostic role of right ventricle (RV) dysfunction in patients with COVID-19 respiratory failure. We agree with Paternoster et al. that growing evidence (and the experience of our center) , indicate that the right ventricle (RV) should be the main target of the echocardiographic assessment in COVID-19 disease, including accurate measurements of its dimensions, function, and estimation of systolic pulmonary arterial pressures (sPAP). The relationship between RV dysfunction and mortality in patients with COVID-19 seems to be dependent on the severity of disease. While papers selected in the meta-analysis by Paternoster et al. included heterogeneous populations, studies including only critically ill patients with COVID-19 failed to document a relationship between mortality and RV dysfunction. , Bearing in mind the complex relationship among RV dysfunction, COVID-19 disease severity, and mortality, it is important to define the clinical significance of RV changes in COVID-19 infection.

Serial echocardiography and an appreciation of the characteristic features of COVID-19–induced respiratory failure may provide insights. As discussed by Dandel , and others, , RV dilatation and dysfunction reflect and follow COVID-19–induced pulmonary thrombotic microangiopathy, a feature recognized as a characteristic pattern of COVID-19. , Thus, RV dilatation and dysfunction may be considered a marker of COVID-19 disease severity but may not fully explain why these changes are not directly related to mortality, especially in critically ill patients. , In contrast, RV dilatation is known to adversely affect prognosis in adult respiratory distress syndrome resulting from other causes. ,

COVID-19–related respiratory changes also demonstrate atypical heart-lung interactions. The relationship between the RV and the pulmonary vasculature in COVID-19 respiratory failure is emphasized by the role of echocardiographic indices of coupling between RV function and pulmonary circulation as prognostic indicators, such as the tricuspid annular plane systolic excursion-to-sPAP ratio. The tricuspid annular plane systolic excursion and/or sPAP recently was investigated in 92 patients with COVID-19–related acute respiratory failure (64%) requiring ventilatory support, and was shown to be an independent predictor of death, with a calculated cut-off of 0.635 mm/mmHg. Because RV failure is more frequent and pronounced in more severe forms of COVID-19 respiratory failure, it can be presumed that different echocardiographic patterns may be detectable across disease severity progression, probably from isolated systolic pulmonary hypertension to overt RV dilatation and dysfunction. Accordingly, in 28 patients with COVID-19–related acute respiratory distress syndrome (ARDS) admitted to our intensive care unit (ICU) assessed by serial echocardiography, sPAP was elevated in all patients on ICU admission but subsequently declined during ICU stay. In mechanically ventilated patients with COVID-19 weaned from extracorporeal membrane oxygenation support, serial echocardiography documented a progressive reduction in sPAP. In nonsurvivors (all on extracorporeal membrane oxygenation support), 2 different echocardiographic patterns were identifiable. One group was characterized by RV dysfunction; all of these patients died because of unfavorable progression of COVID-19 pulmonary disease characterized by bilateral pulmonary consolidations. The second group showed higher values of left ventricular ejection fraction and normal RV dimensions and function, but these patients died from septic shock.

Thus, the detection of RV dilatation and dysfunction in a patient with a COVID-19 infection suggests a severe form of COVID-19, characterized by increased pulmonary vascular resistance and RV afterload increase. Echocardiographic monitoring is strongly suggested to detect dynamic RV changes.

Conflict of Interest

None.