Population-based study of incidence and outcome of acute aortic dissection and premorbid risk factor control: 10-year results from the Oxford Vascular Study.

BACKGROUND: Acute aortic dissection is a preventable life-threatening condition. However, there have been no prospective population-based studies of incidence or outcome to inform an understanding of risk factors, strategies for prevention, or projections for future clinical service provision. METHODS AND
RESULTS: We prospectively determined incidence and outcomes of all acute aortic dissections in a population of 92 728 in Oxfordshire, United Kingdom, from 2002 to 2012. Among 155 patients with 174 acute aortic events, 54 patients had 59 thoracoabdominal aortic dissections (52 incident events: 6/100 000, 95% confidence interval, 4-7; 37 Stanford type A, 15 Stanford type B; 31 men, mean age=72.0 years). Among patients with type A incident events, 18 (48.6%) died before hospital assessment (61.1% women). The 30-day fatality rate was 47.4% for patients with type A dissections who survived to hospital admission and 13.3% for patients with type B dissections, although subsequent 5-year survival rates were high (85.7% for type A; 83.3% for type B). Even though 67.3% of patients were on antihypertensive drugs, 46.0% of all patients had at least 1 systolic BP ≥180 mm Hg in their primary care records over the preceding 5 years, and the proportion of blood pressures in the hypertensive range (>140/90 mm Hg) averaged 56.0%. Premorbid blood pressure was higher in patients with type A dissections that were immediately fatal than in those who survived to admission (mean/standard deviation pre-event systolic blood pressure=151.2/19.3 versus 137.9/17.9; P<0.001).
CONCLUSIONS: Uncontrolled hypertension remains the most significant treatable risk factor for acute aortic dissection. Prospective population-based ascertainment showed that hospital-based registries will underestimate not only incidence and case fatality, but also the association with premorbid hypertension.