OBJECTIVES:

Streptococcus pneumoniae is a common cause of diseases such as community-acquired pneumonia, meningitis, and sepsis across all age groups. In Japan, routine pneumococcal vaccinations are carried out for children aged ≤5 years and older persons aged ≥65 years due to their higher risk of infection. Acute S. pneumoniae infections are reported to elevate the risk of subsequent cardiovascular events such as coronary heart disease, heart failure, arrhythmia, and stroke. In order to generate evidence for the development of optimal vaccination strategies, this study analyzed the effects of S. pneumoniae infections on the risk of subsequent cardiovascular events.

METHODS:

The study was performed using insurance claims data from 3 Japanese municipalities between April 2014 and March 2020. Patients with S. pneumoniae infections were identified through recorded diagnoses in the claims data. Using ICD-10 codes, we examined the occurrence of subsequent cardiovascular events (coronary heart disease, heart failure, arrhythmia, and stroke). Non-infected patients were matched with infected patients according to age (within 5 years), sex, and Charlson Comorbidity Index score. Matched infected and non-infected patients were followed-up from the first S. pneumoniae infection date of each infected patient. The Kaplan-Meier method and Cox proportional hazards models were used to estimate the cumulative incidences and hazard ratios of cardiovascular events.

RESULTS:

We analyzed 253,791 eligible subjects, with 489 cases of S. pneumoniae infections. The overall hazard ratios of stroke and arrhythmia for infected patients (relative to non-infected patients) were 1.84 and 1.64, respectively. The Kaplan-Meier method also revealed that S. pneumoniae infections were significantly associated with higher incidences of stroke and arrhythmia.

CONCLUSIONS:

S. pneumoniae infections elevate the risk of subsequent cardiovascular events such as stroke and arrhythmia. Identifying the increased risk of various life-threatening complications after S. pneumoniae infections can inform the expansion and optimization of vaccination strategies.