Abstract 5903: Association Between Pneumococcal Vaccination and Fewer Adverse Outcomes in Patients Hospitalized With Acute Coronary Syndromes
Background: Prior studies have shown an association between the inflammatory responses generated by bacterial infections and the development of acute coronary syndrome (ACS).
Objective: To examine the association between pneumococcal vaccination and subsequent cardiovascular adverse outcomes in patients hospitalized with suspected ACS.
Methods: This is an observational study of 1436 patients hospitalized at a tertiary VA hospital with suspicion of an ACS that were eligible for pneumococcal vaccination based on current guidelines. We used Cox regression to model associations between pneumococcal vaccination and adverse outcomes, adjusting for influenza vaccination and relevant covariates. We also used propensity score adjustment to account for potential selection bias. The two primary outcomes were death and recurrent myocardial infarction (MI) within 6 months.
Results: Most patients were white (78.2%) and male (97.7%); 65.3% had received pneumococcal vaccination. Overall, 7.9% of vaccinated patients and 26.9% of unvaccinated patients died by 6 months, and 3.5% of vaccinated patients and 5.2% of unvaccinated patients had a subsequent MI. Compared to patients who did not receive either pneumococcal or influenza vaccinations, those who received pneumococcal vaccination had significantly reduced risk of death (HR=0.13; 95%; CI=0.07– 0.23; p<0.001 for those without influenza vaccine and HR of 0.66 (95% CI=0.47–0.92; P=0.02) for those who also received influenza vaccine). Patients who received influenza but not pneumococcal vaccine were at highest risk of death (HR=1.88; 95% CI=1.33–2.64; p<0.001). Patients who received pneumococcal vaccine also were at reduced risk of subsequent MI (HR=0.58; 95% CI=0.32–1.03 for those who did not receive influenza vaccine; p=0.06) and HR of 0.41, 95% CI, 0.21– 0.80, for those who also received influenza vaccine p<0.01). Results were unchanged by covariate or propensity score adjustment.
Conclusions: Among patients hospitalized with ACS, pneumococcal vaccination was associated with a significant reduction in death and borderline to significant reductions in MI. Pneumococcal vaccination may be an effective preventive measure to reduce adverse outcomes in patients at high risk of cardiovascular events.