Stable population-based incidence of acute type A and B aortic dissection

Abstract

Background. Aortic dissection (AD) and abdominal aortic aneurysm (AAA) share the same risk factors. Whereas the incidence of AAA is falling, it is unclear whether population-based incidences of acute type A and B AD have changed. The aim of this study was to investigate incidences of AD subtypes over time. Methods. Citizens in the municipality of Malmö, Sweden, diagnosed with AD in 2000–2004 and 2014–2016 were identified through the in-patient, clinical, and forensic autopsy registers. Results. The overall and gender-specific incidences of acute type A and B AD were stable over time. The overall autopsy rate declined from 25.2% in 2000–2004 to 16.1% in 2014–2016 (p =.0001) and patients with acute type A AD were more often encountered at autopsy (78% of cases) during the first time period, compared to 43% of cases during the second time period (p =.005), when the ratio of acute type A: acute type B AD was 2.6: 1. The proportion of individuals <65 years of age tended to be higher in acute type A AD compared to acute type B AD (p =.07). The frequencies of hypertension and smoking were 90% and 91%, respectively, in type A AD, and 86% and 86%, respectively in type B AD. Conclusions. Population-based incidences of acute type A and type B AD were stable over time, but the decreasing autopsy rate has led to a lower proportion of AD diagnosed at autopsy. Primary prevention towards hypertension and smoking seem necessary to reduce AD incidence.