A Call for Pragmatic Bedside Assessment of Right Ventricular (RV) Function in Coronavirus Disease 2019 (COVID-19).

To the Editor:

We read with interest Isgro et al.’s recent article, describing the potential for right ventricular dysfunction (RVD) in critically ill patients with coronavirus disease 2019 (COVID-19). We agree that the combination of micro/macro thrombi, myocardial injury, sepsis with a profound systemic inflammatory response, along with the combination of Acute Respiratory Distress Syndrome and injurious invasive ventilation, are likely to reflect a perfect storm of pathophysiology in which right ventricular (RV) dysfunction is highly likely to occur.

The authors suggest that RVD is present when echocardiography parameters (including RV fractional area change, tricuspid annular plane systolic excursion and pulsed-Doppler S'Wave velocity) are “less than the lower value of the normal range.” While we wholeheartedly support the use of echocardiography as the cornerstone technique for assessment of RV function in this patient group, we call for a pragmatic approach that includes the combination of both qualitative and quantitative parameters.

The quantitative parameters described by the author have not yet been validated in this population, either to a clinical endpoint or against a reference method. In other settings, they have been shown to be inconsistent for prediction of poor RV function when compared with reference methods, and perhaps more challengingly, have been observed to vary in their predictive performance depending on the degree of RVD present.

Indeed, in the prospective study of 100 consecutive patients with COVID-19 presenting to the hospital by Szekely et al., even in the most critically ill cohort (those receiving invasive mechanical ventilation, n = ten), mean ± standard deviation values for pulsed Doppler S'Wave velocity and tricuspid annular plane systolic excursion were within the normal range (10.1 ± 3cm/s and 2.1±cm, respectively). Yet, in this cohort, RV dilatation (as measured by RVEDA) right ventricular end diastolic area was a common abnormality. Where quantitative parameters are used, their combination may allow better discrimination of normal and abnormal RV function. Two-dimensional speckle-tracked RV longitudinal strain has been suggested as a method to overcome some of the difficulties associated with the conventional quantitative parameters and, although showing promise in research settings, has not yet found widespread use in clinical practice.

During the pandemic, critical care echocardiography, delivered by clinicians at the bedside, has been essential for the management of critically ill patients with COVID-19. In such a setting, focused intensive care echocardiography often does not include the ability to measure quantitative parameters and is reliant on answering qualitative questions; is the RV dilated or not? Is there RV dysfunction or not? We have heard anecdotal reports of quantitative echocardiography (such as that offered by an accredited echocardiography service) not being available in “red-zone” (COVID) intensive care units due to concerns regarding staff safety.

We agree with Isgro et al. that there is a need for large-scale prospective echocardiography data in COVID-19 patients. To this end we are conducting a multicenter prospective transthoracic echocardiographic study, to explore the incidence of RV dysfunction in critically ill patients ventilated with COVID-19 (COVID-RV), which currently is recruiting in 12 Scottish intensive care units. Given the difficulties in RV assessment described, the presence of RVD for this study includes the qualitative parameters of RV dilatation, interventricular septal flattening, and a subjective description of “dysfunction.” These measures previously have been demonstrated to be associated without outcome in patients with acute respiratory distress syndrome. , The use of quantitative parameters, including speckle- racked longitudinal strain, will be explored off-line as secondary outcomes and will help provide further mechanistic insights.

Isgro et al. highlighted the need for prospective studies of RV protection in patients with COVID-19. We applaud this aim, and like them, we believe such an approach could lead to meaningful patient benefit. We urge, however, that any research forming such a study, or indeed when describing appropriate inclusion criteria for a trial, should include an echocardiographic definition of RVD that is sufficiently pragmatic to empower the bedside clinician to make the diagnosis.