Survivors of tuberculosis (TB) have a higher risk for ischemic heart disease (IHD), including myocardial infarction (MI), than the general population, according to the results of a large-scale, population-based, retrospective cohort study that used the Korean National Health Insurance Service database. Results of the study were published in the journal Clinical Infectious Diseases.
The study defined TB survivors based on the following criteria: patients with 2 or more health care uses (outpatient visits, emergency department visits, or hospitalizations) with the ICD-10 codes associated with active TB and specific insurance codes; and patients who were prescribed 2 or more anti-TB medications (isoniazid, rifampin, ethambutol, pyrazinamide, cyclosporine, and para-aminosalicylate) for 90 days or longer.
The primary study endpoint was IHD diagnosed during the follow-up period. The researchers also evaluated the participants for the presence of MI. The study enrolled a total of 60,602 TB survivors, along with an equal number of age- and sex-matched control patients. Mean patient age was 52.4 years and approximately 42.3% of the participants were women. All eligible participants were observed for 1 year after their TB diagnosis to the date of the IHD event, the date of death, or the end of the study period (December 31, 2018) whichever occurred first.
Results of the study showed that during a median 3.9 years of follow-up, 2.7% of the TB survivors and 2.0% of the control patients developed IHD. Further, 0.6% of the TB survivors and 0.4% of the control patients developed MI.
The overall risk for development of IHD and MI was higher among patients with TB (adjusted hazard ratio [aHR], 1.21; 95% CI, 1.12-132 for IHD; and aHR, 1.48; 95% CI, 1.23-1.78 for MI) than among the control patients. Based on stratified analysis, survivors of TB have an increased risk for IHD and MI regardless of their place of residence, income, alcohol consumption, smoking status, body mass index, physical activity, and Charlson comorbidity index.
Several limitations of the study include the investigators’ use of a database of insurance claims data, which creates the possibility of undetected or misclassified TB diagnoses. Additionally, because of the inherent limitations of claims data, the severity of TB and the presence of permanent sequelae, which can impact the development of IHD, could not be measured. Moreover, the possibility of reverse causality exists.
“Physicians should be aware of the risk of IHD in patients with TB and provide adequate preventive management,” the study authors wrote. “Further studies are needed to clarify the exact mechanisms underlying this association and to verify whether TB control strategies can reduce the risk of IHD.”
Lee HR, Yoo JE, Choi H, et al. Tuberculosis and the risk of ischemic heart disease: a nationwide cohort study. Clin Infect Dis. Published online December 15, 2022. doi:10.1093/cid/ciac946