Blood pressure and the risk of major adverse cardiovascular events among firefighters

Abstract

No long-term follow-up study has investigated the effect of blood pressure (BP) on cardiovascular disease mortality and morbidity in firefighters. To investigate the effects of BP on the risk of major adverse cardiovascular events (MACEs) using a national representative population-matched cohort. We enrolled all firefighters (N = 8242) and 28 678 referent controls aged more than 40 years who underwent baseline health examinations in 2002 and 2003. Records of hospitalization and mortality until 2015 were checked. To evaluate the causal effect of BP on MACE, subcohort analysis using a propensity score-matched (PSM) cohort with respect to job classification (firefighter vs. control) was performed. Hypertension significantly increased the risk of MACEs compared with normal BP in both firefighters and the age--sex matched cohort, but in participants with elevated BP, significantly increased risk of MACEs [hazards ratio 1.41, 95% confidence interval (CI) 1.06-1.88] was observed only among firefighters. In the PSM cohort, firefighters had a significantly higher risk of death or hospitalization from MACEs (hazard ratio 1.29, 95% CI 1.14-1.47), myocardial infarction (hazard ratio 1.24, 95% CI 1.07-1.43), and ischemic stroke (hazard ratio 1.43, 95% CI 1.12-1.82) than controls. Firefighters with elevated BP (hazard ratio 1.58, 95% CI 1.04-2.40), stage 1 (hazard ratio 1.24, 95% CI 1.00-1.52), and stage 2 (hazard ratio 1.39, 95% CI 1.13-1.71) hypertension had higher risk of MACEs than PSM controls. Firefighters showed significantly higher cardiovascular risk than referent controls when comparing those within the same BP category, suggesting that firefighters with elevated BP and hypertension may be at high risk of adverse prognosis.