Echocardiographic characterisation in critical Covid19 - an observational study

Objective We aimed to investigate the acute cardiac effects of severe SARS-CoV-2. Methods This is an observational study generated from the first 79 patients admitted to Uppsala intensive care due to respiratory failure with SARS-CoV-2 infection. 34 underwent echocardiography of which 25 were included in the study and compared to 44 non-echo patients. Exclusion was based on absence of normofrequent sinus rhythm and mechanical respiratory support. Biomarker analysis was carried out on all patients. Results Mortality was increased in the echo compared to non-echo group (44 % vs. 16%, p<0.05). Right sided dimensions and functional parameters were not affected. Tricuspid regurgitation velocity indicated how increased pulmonary artery pressure was associated with mortality (survivors (n=5): 2.51 ± 0.01 m/s vs. non-survivors (n=5): 3.06 ± 0.11 m/s, p<0.05). Cardiac markers and D-dimer correlated to initiation of echocardiography (hs-TnI (ng/L): echo (n=23): 133 ± 45 vs. non-echo (n=41): 81.3 ± 45, p<0.01; NTproBNP (ng/L): echo (n=25): 2959 ± 573 vs. non-echo (n=42): 1641 ± 420, p<0.001; D-dimer (mg/L): echo (n=25): 16.1 ± 3.7 vs. non-echo (n=43: 6.1 ± 1.5, p<0.01) and mortality (hs-TnI (ng/L): survivors (n=48): 59.1 ± 21 vs. non-survivors (n=17): 211 ± 105, p<0.0001; NT-proBNP (ng/L): survivors (n=47): 1310 ± 314 vs. non-survivors (n=20): 4065 ± 740, p<0.0001; D-dimer (mg/L): survivors (n=50): 7.2 ± 1.5 vs. non-survivors (n=18): 17.1 ± 4.8, p<0.01). All intervals refer to standard error of the mean. Tricuspid regurgitation velocity was correlated with troponin I (r=0.93, r 2 =0.74, p<0.001, n=10). Conclusions These results suggest that there is no clear negative effect on cardiac function in critical SARS-CoV-2. There are indications that pulmonary pressure elevation carries a negative predictive outcome suggesting pulmonary disease as the driver of mortality. Cardiac biomarkers as well as D-dimer carry predictive value. Trial registration number Patients were included in “Clinical trials NCT04316884 ” Article summary Strength and limitations of this study - The patient body is recruited from all patients admitted to ICU in need of mechanical respiratory support independent of background which makes it relevant to clinical practice. - The echocardiographic image acquisition was carried out by hospital assigned agents on clinical indication, which makes the results applicable in a clinical setting. - Since the image acquisition was carried out on a clinical indication, the results may be skewed towards the false positive if applied to all Covid19 patients.