| Summary: | 碩士 === 中國醫藥大學 === 臨床醫學研究所碩士班 === 101 === Introduction
A link between infection and the incidence of acute coronary syndrome (ACS) has been suggested. The reason of infection leading to ACS maybe explained by increased inflammation, hemoconcentration, imbalance between oxygen demand and supply. Of all bacterial infections, pneumonia is mostly associated with the development of ACS.Streptococcus pneumonia is the most common causative pathogen of community acquired pneumonia, and Streptococcus pneumonia infection is asscociated with clinically severe form of pneumonia. However, relatively few studies have specifically discussed the association between pneumococcal pneumonia and ACS. This study focuses on investigating the association between pneumococcal pneumonia and the development of ACS. This is an important research topic, because it may provide a rationale for implementing pneumococcal vaccination in preventing ACS, especially in Asian populations.
Materials and methods
We conducted a longitudinal cohort study from the Taiwan National Health Institute Research Database (NHIRD). The study sample consisted of 20111 patients who received the first diagnoses of pneumococcal pneumonia between 1997 and 2010. We age and sex-matched these participants with 80444 control patients without a previous diagnosis of either pneumococcal pneumonia or ACS. We first compared the differences of baseline demographics between the two groups with chi-square test.We consider hypertension, diabetes, hyperlipidemia, and chronic obstructive pulmonary disease as potential covariates. We used the follow-up person-years to assess the incidence density rates until ACS was either identified or censored.We used Poisson regression models to evaluate the ratios of the pneumococcal pneumonia cohort to the controls (relative risk) and 95% confidence intervals (CI). We used the Cox proportional-hazards model to investigate whether pneumococcal pneumonia is independently associated with ACS after adjusting for all potential risk factors. We then used Kaplan-Meier analysis and the log-rank test to compare the cumulative risk of developing ACS between the 2 groups.
Results
The incidence of ACS was 43.1 per 10000 person-years in the pneumococcal pneumonia and 22.4 per 10000 person-years in the control group.(Incidence rate ratio: 1.92; 95% confidence interval: 1.70-2.17). Higher proportions of hypertension, diabetes, hyperlipidemia and chronic obstructive pulmonary disease are noted in the pneumococcal pneumonia group. After adjusting for age, sex, and comorbidities, we found that the risk of ACS was 47% higher in the pneumococcal pneumonia group than in the control group (95% confidence interval: 1.24-1.73). We divided the time lag into 3 periods, (≤ 3 mo, 3 mo to 1 y and >1 y), and found that the highest relative risk of incidence of ACS between the 2 groups was within the first 3 months after infection with pneumococcal pneumonia (Incidence rate ratio: 3.90; 95% confidence interval: 2.46-6.18). The Kaplan-Meier survival curve showed that the risk of ACS was higher in the pneumococcal pneumonia group than in the control group (Log-rank test, P<0.0001).
Conclusion
Pneumococcal pneumonia is associated with an increased incidence of ACS, and the relative risk of incidence of ACS between the two groups is highest within the first three months. Our study implied that pneumococcal vaccination may be considered as an option for prevention of incidence of ACS.
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