Danish Study of Type A and B Aortic Dissections
- In a nationwide, population-based registry study of Danish hospital admissions from 1996–2016, the overall mean annual incidence of aortic dissection was 4.2/100,000 patient-years.
- The respective 30-day mortality rates for type A aortic dissection (TAAD) and type B aortic dissection (TBAD) were 22.0% and 13.9% (p < 0.001), with no significant changes over time or between sexes.
- Among 30-day survivors, the all-cause 5-year mortality was comparable to the general hypertensive population for patients with TAAD, but significantly higher for patients with TBAD.
What are the clinical characteristics, incidences, and mortality rates for adult patients admitted with type A aortic dissection (TAAD) or type B aortic dissection (TBAD)?
In a nationwide, population-based registry study, all cases of registered aortic dissection (AD) with International Classification of Diseases, Tenth Revision codes in the Danish National Patient Registry at the time of admission to a hospital from 1996–2016 and with available medical records underwent validation. Data were merged between nationwide health registries, including the cause of death registry. Patients with validated AD were matched 1:10 based on sex and age with patients with hypertension from the general Danish population.
Of 5,018 registered cases of AD, 4,183 cases underwent review and 3,023 (60.2%) were confirmed as AD. After exclusions, the respective distribution of validated TAAD and TBAD was 1,620 (60.5%) and 1,059 (39.5%, p < 0.001), of whom 67.5% and 67.0% were men, with respective mean ages at dissection of 63.5 ± 12.9 and 67.5 ± 12.2 years (p < 0.001). The most prevalent comorbidities for TAAD were hypertension (55.2%), thoracic aortic aneurysms (14.6%), and chronic obstructive pulmonary disease (COPD; 13.1%); for TBAD, the most prevalent comorbidities were hypertension (64.1%), aortic aneurysms at any location (7.5-12.0%), and COPD (15.7%). The overall mean annual incidence rate was 4.2/100,000 patient-years. The incidence was significantly higher for TAAD (2.2/100,000) compared with TBAD (1.5/100,000, p < 0.001). The respective 30-day mortality rates for validated TAAD and TBAD were 22.0% and 13.9% (p < 0.001), with no significant changes over time or between sexes. Compared to the general hypertensive population, the adjusted 5-year overall mortality rates for TAAD and TBAD were hazard ratio 3.2 (2.9-3.5, p < 0.001; aortic-related cause of death 57.0%) and hazard ratio 2.1 (1.9-2.4, p < 0.001; aortic-related cause of death 42.8%), respectively. Among patients who survived 30 days from dissection, the adjusted 5-year overall mortality rates were hazard ratio 1.1 (1.0-1.3, p = 0.12; aortic-related cause of death 23.2%) for TAAD, and hazard ratio 1.4 (1.2-1.6, p < 0.001; aortic-related cause of death 25.6%) for TBAD.
Hypertension, aortic aneurysms, and COPD were the most prevalent comorbidities among patients admitted with AD. The 30-day mortality rates were consistent over time, with no significant differences between sexes. The 5-year mortality rate was higher for TAAD than TBAD. However, if a patient survived 30 days from dissection, the mortality rate for patients with TAAD was comparable to that of the general hypertensive population, whereas the mortality rate was significantly higher among patients with TBAD.
Most data about AD are derived from high-volume centers such as the International Registry of Acute Aortic Dissections (IRAD). The present study describes the nationwide, population-based epidemiology and outcomes of AD using data from the Danish National Patient Registry merged with other Danish health care registries over a 2-decade interval from 1996 to 2016. Findings include a predominance of male sex in both TAAD and TBAD; increased frequency of AD in people >60 years of age (with AD presenting at an older age in women than in men); 30-day mortality rates that were stable over time with no significant differences between sexes; and higher 5-year mortality associated with TAAD compared to TBAD; and higher mortality compared to the general hypertensive population among 30-day survivors of TBAD but not 30-day survivors of TAAD. Although data from a national patient registry could tend to underestimate the true incidence of AD owing to death prior to hospital admission, and with other limitations inherent to any registry-based study, this study provides important insight into the epidemiology and outcomes of AD over an extended interval.
Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Prevention, Vascular Medicine, Aortic Surgery, Cardiac Surgery and Arrhythmias, Interventions and Vascular Medicine, Hypertension
Keywords: Aneurysm, Dissecting, Aortic Aneurysm, Thoracic, Cardiac Surgical Procedures, Comorbidity, Hypertension, Pulmonary Disease, Chronic Obstructive, Secondary Prevention, Survival Rate, Vascular Diseases
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