Abstract 17817: The Incidence and Mortality Risk of Acute Thoracic Aortic Dissection: Results From a Nationwide Population-based Study

Abstract

Introduction: Acute thoracic aortic dissection is a potentially lethal disease associated with high morbidity, however, contemporary data on incidence and mortality risk are lacking. Utilizing a nationwide data comprising the Icelandic population we aimed to determine the incidence, mortality and the time-dependent mortality risk of acute thoracic aortic dissection. Methods: Data was retrospectively collected using hospital discharge registries in Iceland from 1992-2013 as well as autopsy database from Medical Examiner Office. To capture all cases diagnostic codes for dissection (ICD-9: 441.1 and ICD-10: I71.0) were queried as well as for aortic aneurysm and arterial dissection. Total of 1811 charts were reviewed resulting in 153 confirmed diagnoses of acute thoracic aortic dissection. Demographics, medical history, risk factors and clinical symptoms were collected for all patients. Incidence was calculated using age and gender specific information provided by National Statistics Iceland. Results: Age and gender-adjusted incidence of acute thoracic aortic dissection was 2.5/100,000/year and no significant change in incidence was observed. The mean age was 66.9±13.6 years, 61% (94/153) were males and 66% (101/153) were Stanford type A. Of all patients diagnosed with dissection 18% (27/153) died prior to hospital arrival while the risk of death for all patients that arrived alive to a hospital was 21% (27/126) within 24 hours and 45% (57/126) at 30 days. Predictors for short-term mortality included female sex, renal disease and family history of dissection. The overall 10-year survival was 39% of which negative predictors included age, coronary artery disease, renal disease, peripheral vascular disease and family history of dissection. During the course of the study the 30-day mortality rate decreased by 0.96/year, (95% CI: 0.92- 0.99) and the 10-year survival improved significantly (p=0.04). Conclusions: Acute thoracic aortic dissection is uncommon but a lethal condition where two thirds of patients die within 30 days of the index event. The incidence remained constant but a decline in short-term mortality and increased long-term survival was observed indicating improved overall outcome in patients diagnosed with this complex condition.