Comparison of ECG Features, Cardiac Biomarkers, and Clinical Outcomes In Three Waves of Hospitalized COVID-19 Pneumonia Patients with Cardiovascular Events

Background Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is a rapidly evolving virus that can severely impact the cardiovascular system. With new variants, it is important to characterize wave-specific (defined by dominant circulating variants) clinical changes. Methods A multi-center retrospective cohort study of patients hospitalized with SARS-CoV-2 community acquired pneumonia at eight adult acute-care hospitals in the city of Louisville, KY was conducted. Patients hospitalized with Coronavirus Disease 2019 (COVID-19) community acquired pneumonia who experienced a cardiovascular event between March 2020 and July 2022 were included in this analysis. Variant assignment was based on temporal prevalence rather than genomic confirmation, and gaps between study periods reflected intervals during which the three variants were not dominant. Results Wave 1 showed significantly higher right bundle branch block (RBBB) (19.4% vs. 6.1%, P = 0.019) and brain natriuretic peptide (BNP) levels (4,598.73±7,764.72 vs. 1,161.33±3,305.48 pmol/L, P = 0.016) in cardiovascular patients on the first electrocardiogram (ECG). On the event triggered ECG, Wave 1 had higher ventricular/pacing rhythm and ST elevation than Wave 2 (8.9% vs. 2.3%, P = 0.033; 6.9% vs. 1.6%, P = 0.039). Wave 2 demonstrated elevated heart rate on the event triggered ECG among non-survivors (115.23±30.7 vs. 99.23±32.2, P = 0.012) and was associated with intensive care unit [1] length of stay (LOS) (ρ = 0.288, P = 0.045). First troponin and BNP levels in sinus rhythm were higher in Wave 3 than Wave 1 (1.7±3.6 vs. 0.2±0.7, P = 0.046). Wave 3 had shorter hospital LOS for survivors at first ECG (median: 8 days), but higher mortality rates for sinus rhythm at event triggered ECG compared to Wave 1 (7.1% vs. 51.6%, P = 0.029). Conclusion Distinct patterns in ECG parameters, cardiac biomarkers, and clinical outcomes in hospitalized COVID-19 patients offer valuable insight into cardiac manifestations of COVID-19, especially as vaccination rates and clinical practices evolve.