New-onset aortic dilatation in the population: a quarter-century follow-up.

Background: Aortic size tends to increase with aging but the extent of this dynamic process has not been evaluated in long-term longitudinal population-based studies. We investigated the incidence of new-onset aortic root (AR) dilatation and its principal correlates among middle-aged adults over a 25-year time period.

Methods: A total of 471 participants with measurable echocardiographic parameters at baseline and after a 25-year follow-up were included in the analysis. Sex-specific upper limits of normality for absolute AR diameter, AR diameter indexed to body surface area (BSA) and to height were derived from healthy normotensive PAMELA participants.

Results: New AR dilatation occurred in 7.4% (AR/BSA), 9.1% (AR/height) and 14.6% (absolute AR), respectively. According to the AR/height index, the risk of new dilation was similar in men and women. As for echocardiographic parameters, baseline AR diameter emerged as a key predictor of AR dilation, regardless of the diagnostic criteria and the 10-year change in LVMI was positively associated to new AR/height dilatation. No significant relationship was observed between baseline office and ambulatory systolic/diastolic blood pressure or their changes over time with incident AR dilatation. Baseline and the 25-year change in 24-h pulse pressure were negatively related to new AR dilatation.

Conclusions: The incidence of AR dilatation from mid to late adulthood occurs in a small but clinically relevant fraction of participants and is unaffected by both office and out-office BP. It is significant related to baseline AR diameter and to the 25-year change in LVMI. Our data suggest that echocardiography performed in middle-aged individuals of both sexes may identify those at increased risk of future AR dilatation; moreover, preventing LVH may reduce the risk of progressive AR enlargement.