Reciprocal relationship between herpes zoster and cardiovascular diseases: A nationwide population‐based case–control study in Korea

Abstract Recently, herpes zoster ( HZ ) has been identified as a risk factor for stroke, but there have been few studies on the relationship between HZ and other cardiovascular diseases ( CVD ), including myocardial infarction ( MI ) and heart failure ( HF ). The purpose of this study was to investigate the risk of HZ occurrence after CVD and the occurrence of CVD after HZ . This was a retrospective case–control study based on the National Health Insurance System claims database for 20 311 patients with HZ and 13 980 patients with CVD and 1:5 age‐ and sex‐matched control subjects for each from January 2006 to December 2013. We evaluated the reciprocal relationship between HZ and CVD including MI , ischemic stroke and HF . Severe HZ requiring hospitalization independently increased the risk of subsequent MI (hazard ratio [ HR ], 1.831; 95% confidence interval [ CI ], 1.354–2.476)], ischemic stroke ( HR , 1.523; 95% CI , 1.212–1.915) and HF ( HR , 2.034; 95% CI , 1.615–2.562) during the study period. Likewise, patients with an episode of MI , ischemic stroke or HF were also at increased risk of HZ hospitalization (after MI : HR , 1.625; 95% CI , 1.144–2.308; after stroke: HR , 1.518; 95% CI , 1.177–1.957; and after HF : HR , 1.485, 95% CI 1.041–2.117). Our results suggest that there is a significant reciprocal relationship between severe HZ requiring hospitalization and CVD including MI , ischemic stroke and HF .