Background The coronavirus disease (COVID-19) due to the novel SARS-CoV2 has rapidly spread as pandemic worldwide. COVID19 caused varying degrees of illness. The aim of the present study was to compare clinical and electrocardiographic characteristics of first-wave COVID-19 patients with a group of patients affected by community-acquired pneumonia.
Methods All-comer consecutive patients referred to the Emergency Department of Modena University Hospital from March the 16th to April the 15th 2020 and diagnosed with COVID19 were compared with a cohort of patients affected by community-acquired pneumonia (CAP) admitted during the same seasonal period of 2019. The primary endpoint was 30-day mortality. We also investigated 1-year mortality.
Results COVID-19 patients were younger (66,5±15,8 vs 71,2±20,5, p=0,041) compared to CAP-patients; the most common symptom in this setting was fever (87,9% vs 68,1%, p<0,001). COPD (26,4% vs 9,2%, p<0,001), smoking habit (15,3% vs 6,3%, p=0,019), cancer (18,1% vs 9,2%, p=0,035) and atrial fibrillation (23,6% vs 11,7%, p=0,012) were all more common in CAP-patients, who presented also higher levels of troponin (100,4±148,2 vs 44,57±46,5, p=0,029) and white blood count (8,9±4,4 vs 6,9±3,5, p<0,001). Radiological findings differed significantly between the two groups, with interstitial pneumonia as primary presentation in COVID-19 patients (83,3% vs 11,3%, p<0,001). ECG registrations, if available, showed frequent ventricular repolarization alterations in COVID-19 patients (21,2% vs 6,2%, p=0,008). The primary end-point was significantly higher in COVID-19 patients compared to CAP-patients (18.8% vs 4,2%, p=0,001), but no statistical difference was noted at 1-year (23.8% vs 20.8%, p=ns). During the first wave, COVID-19 patients presented 5-fold risk of 30-day mortality compared to CAP-patients (OR 5.81, 1.36-24.79, p=0.02). A Cox egression proportional hazards model was used to evaluate the correlation between ECG alterations and the primary endpoint. At multivariate analysis, after adjustment for confounding factors selected trough the stepwise backward selection, only age>75years remained an independent 30 day-mortality predictor for COVID-19 patients.
Conclusion In our retrospective case-control study, we confirmed that COVID-19 patients presented a higher 30-d mortality compared to CAP-patients. This difference seems to decrease in the long-term, probably due to the different clinical features of these two populations. Age>75 remained the strongest independent 30-day predictor of mortality in COVID-19 patients. Our results must be confirmed in larger and dedicated studies.