# COVID-19 vaccination and mortality among coronary care patients with severe acute respiratory infection in Bangladesh: a prospective study (2021–2024)

## TL;DR

This study found that COVID-19 vaccination was linked to lower mortality in Bangladeshi patients with severe respiratory infections and heart complications.

## Contribution

The study provides new evidence on the protective effect of COVID-19 vaccination in reducing mortality among patients with cardiovascular complications and SARI in Bangladesh.

## Key findings

- Vaccinated patients had an 89.6% survival rate compared to 81.4% in unvaccinated patients.
- AMI was associated with higher mortality, while vaccination was protective against all-cause mortality.
- SARS-CoV-2 and influenza were detected in 6.8% and 4.8% of patients, respectively.

## Abstract

COVID-19 increases cardiovascular risk, and vaccination reduces adverse outcomes and mortality. We analysed national hospital-based sentinel surveillance data from Bangladesh, and the aim of the study was to identify factors associated with all-cause mortality among patients with cardiovascular complications.

We included patients from coronary care units in nine tertiary-hospitals between February 2021 and December 2024 with severe acute respiratory infections (SARI). Nasopharyngeal and oropharyngeal swabs were tested for SARS-CoV-2 and influenza viruses by multiplex rRT-PCR. Patients were followed up from hospital admission to 30 days post-discharge. Survival was assessed with Kaplan–Meier estimates stratified by vaccination status and compared using log-rank test. Risk factors for all-cause mortality were analysed using multivariable Cox proportional hazards regression, stratified by hospital type.

We enrolled 396 patients (median age 60, IQR: 48–65 years), and 70.5% (279/396) were male. The Median follow-up time was 33 days (IQR: 32–34 days). There were 13.9% (55/396) deaths, 41.2% (163/396) had acute myocardial infarction (AMI) and 71.2% (286/396) were COVID-19 vaccinated patients. SARS-CoV-2 and influenza viruses were detected among 6.8% (27/396) and 4.8% (19/396) patients, respectively. At follow-up, the survival rate was 89.6% in COVID-19 vaccinated patients compared to 81.4% in unvaccinated patients (P-value = 0.041). AMI was associated with higher mortality [HR = 1.74, (95% CI: 1.01–3.02), P-value = 0.048] while COVID-19 vaccination was protective [HR = 0.55, (95% CI: 0.32–0.96), P-value = 0.037].

COVID-19 vaccination was associated with reduced all-cause deaths among SARI patients with cardiovascular complications.

Centres for Disease Control and Prevention (CDC), Atlanta, Georgia, USA (U01GH002259). ZA is supported by UNSW by a UIPA PhD scholarship.