Herpes zoster infection associated with acute coronary syndrome: a population-based retrospective cohort study

Background Vasculopathy in varicella zoster virus (VZV) infection and a proposed association between herpes virus infection and atherosclerosis suggest a possible link between VZV infection and vascular thrombosis. Objectives To determine the risk of acute coronary syndrome (ACS) associated with herpes zoster infection. Methods We used the Taiwan National Health Insurance Research Database to identify 57 958 patients newly diagnosed with herpes zoster between 1999 and 2010; 231 832 patients without herpes zoster were examined as the control group. Both cohorts were followed up until the end of 2010 to measure the incidence of ACS. Cox proportional-hazards regression and Kaplan-Meier analyses were used to measure the hazard ratios (HR) and the cumulative incidences of ACS, respectively. Results The incidence of ACS was 1.24-fold higher in the herpes zoster group than in the control group [36.8 vs. 29.6 per 10 000 person-years, 95% confidence interval (CI) 1.16-1.33]. After adjusting for age, sex and comorbidities, the HR of ACS for the herpes zoster group compared with the control group was 1 . 15 (95% CI 1.07-1.24). Analysis by the time lag (<= 3 months, <= 1 year, > 1 year) showed that the incidence of ACS remained significantly higher in the herpes zoster group than in the control group, with an adjusted HR of 1 . 10 (95% CI 1.02-1.19) after the 1-year follow-up period. The Kaplan-Meier survival curve showed that the risk of ACS was significantly higher in the herpes zoster group than in the control group (P < 0.001). Conclusion Herpes zoster infection is associated with an increased risk of ACS.