Population-Based Incidence and Outcomes of Acute Aortic Dissection in Rural Areas of Japan

Acute aortic dissection (AAD) is a life-threatening cardiovascular disease. Although various nationwide registries have investigated the clinical characteristics of AAD, data on its incidence and outcomes, particularly in rural areas of Japan, remain limited. We conducted a population-based review of patients with AAD in the Rumoi medical area, a well-defined rural region of Hokkaido. Data were retrospectively collected for patients diagnosed with AAD between January 2014 and December 2023. A total of 67 cases of AAD were identified (type A, 59.7%; n = 40), and 32.8% of patients were dead on hospital arrival. The mean patient age was 75.7 ± 13.1 years, and 59.7% (40/67) were male. The age-adjusted incidence and mortality rates of AAD were 17.3 and 6.45 per 100,000 inhabitants per year, respectively. Of the 45 patients who arrived at the hospital alive, 14 with type A AAD and 10 with type B AAD were transferred to tertiary referral hospitals for emergency surgery or conservative treatment. All transferred patients with type A AAD underwent emergency open aortic surgery, and one patient with type B AAD underwent emergency endovascular surgery. This study demonstrated a higher incidence of AAD than that reported in several previous studies in Japan. In contrast, the 30-day mortality among patients who were alive on arrival was lower than in prior reports. These findings suggest that prompt diagnosis and early transfer to tertiary referral hospitals can reduce the mortality rate even in rural settings.