Follow-up of incidentally detected mild to moderate ascending aortic dilation and risk factors for rapid progression in a Swedish middle-aged population.

Background: Thoracic aortic aneurysm is a life-threatening disease due to the risk for acute aortic syndromes, and subjects with dilated ascending aortas are recommended surveillance imaging to assess the need for preventive surgery. Our objectives were to investigate the progression of dilated ascending aortas and risk factors for rapid progression in a prospectively enrolled general population-based cohort of subjects aged 50-65 years.

Methods: From the 5058 subjects prospectively enrolled in the general population-based Swedish CArdioPulmonary bioImage Study (SCAPIS) in Linköping, we followed all 74 subjects (22% female, mean age 59±4 years) with ascending aortic dilation (≥40 mm) identified by CT angiography, thoracic CT or transthoracic echocardiography. Office and home blood pressure (BP), pulse wave velocity, coronary artery calcification and carotid plaques were assessed at baseline. Transthoracic echocardiography was used to follow ascending aortic diameters over time.

Results: Three subjects underwent acute or elective aortic repair before the first follow-up examination. Among the remaining subjects, the mean progression rate of ascending aortic diameter was 0.4 mm/year (range 0-1.8 mm/year) during a mean follow-up of 6.1±1.3 years. In 10 (14%) subjects, all men, no progression was seen. In multivariable analysis, higher 7-day home systolic BP was the only factor associated with faster progression rate.

Conclusions: Progression of mild to moderate ascending aortic dilation was in general slow. Our findings emphasise the benefit of home BP measurements over office BP and underline the importance of BP control in subjects with a dilated ascending aorta.