Can echocardiographic parameters predict mortality in COVID-19?
Authors: Babu A , Eden N , Meng Z , Lamb D , Bhatia R , Voon V 
Published: October 2021

Abstract

Introduction
The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), otherwise known as the coronavirus (COVID-19) pandemic presents one of the greatest medical challenges of our generation. Whilst commonly causing a viral pneumonitis, myocardial damage has also been suggested by elevated serum troponin values greater than the 99th centile in up to 30% of individuals who require hospitalisation and correlates with increased mortality.

Purpose
We aim to identify whether transthoracic echocardiography (TTE) parameters can elucidate the phenomenon of abnormal troponin levels. Furthermore, we seek to characterise the most frequent demographic, biochemical, echocardiographic features and co-morbidities associated with adverse outcomes in this cohort.

Methods
A retrospective analysis was conducted utilising electronic patient records of consecutive hospitalised patients with a positive COVID-19 swab between 1st March and 31st October 2020 who underwent a TTE at our institution. Pertinent variables were collected including: the clinical indication, demographics including cardiovascular (CV) risk factors, peak troponin values and fundamental echocardiographic parameters.

Results
During this 8-month period, a total of 90 patients underwent a TTE. The mean age of the cohort was 63 years of age and 56% were male. More than half (56.6%) were admitted to the intensive care unit (ICU). A salient 41.1% (n=37) of our cohort succumbed to this devastating virus. Notably, 38.9% (n=35) were of black and minority ethnic origin (BAME). A striking 64.9% (n=24) of patients who died had hypertension. The mean troponin levels were 168.7 ng/L and 176.6 ng/L (0–34 ng/L) in the survivors and non-survivors group respectively. With regards to TTE, the left ventricular parameters were similar between both groups with a mean left ventricular ejection fraction (LVEF) of 60.6% in the non-survivors. Conversely, both right ventricular (RV) dysfunction (37.8%) and raised pulmonary artery systolic pressures (PASP) (51.4%) were markedly more frequent in the patients who perished due to COVID-19 infection.

Conclusion
Remarkably, in this extremely ill group of patients who died, 91.9% of patients had a preserved LVEF. There were no overt differences between troponin levels in the survivors and non-survivors. However, hypertension, RV dysfunction and raised PASP were distinctly more prominent in the non-survivors. Thus, providing insight that a normally functioning left ventricle does not preclude to poor outcomes. Overall, this single-centre retrospective study demonstrates that the echocardiographic phenotype associated with mortality is consistent with a severe respiratory illness rather than direct myocardial injury from COVID-19. A multi-modality imaging approach may facilitate the identification of adverse tissue characterisation changes associated with this novel virus as well as guiding further risk stratification and patient management on a case-by-case basis.

Funding Acknowledgement
Type of funding sources: None.