Cardiac Rehabilitation Protects Against the Expansion of Abdominal Aortic Aneurysm.

Background Virtually no reports on the effects of exercise in patients with a small abdominal aortic aneurysm ( AAA ) exist. Methods and Results We conducted a retrospective cohort study on 1515 patients with a small AAA before surgery at 2 high‐volume hospitals in Tokyo, Japan, from April 2004 to September 2015. A carefully modified cardiac rehabilitation program without excessive blood pressure elevation during exercise was prescribed to 50 patients with an AAA . Using propensity score matching, mortality and clinical outcomes, including AAA expansion rate, were compared between 2 groups: rehabilitation group and nonrehabilitation group. The background characteristics of the rehabilitation group (n=49) and the nonrehabilitation group (n=163) were almost identical. The risk for AAA repair was much lower in the rehabilitation group after matching (before matching: hazard ratio, 0.43; 95% confidence interval, 0.25–0.72; P =0.001; and after matching: hazard ratio, 0.19; 95% confidence interval, 0.07–0.50; P <0.001). AAA expansion rate was slower in the rehabilitation group (before matching: rehabilitation versus nonrehabilitation group, 2.3±3.7 versus 3.8±3.4 mm/y [ P =0.008]; after matching: rehabilitation versus nonrehabilitation group, 2.1±3.0 versus 4.5±4.0 mm/y [ P <0.001]). Elevation of blood pressure during exercise was positively correlated with AAA expansion rate after the rehabilitation program ( r =0.569, P <0.001). Conclusions Cardiac rehabilitation protects against the expansion of small AAA s and mitigates the risk associated with AAA repair, possibly because of the decreased elevation of blood pressure during exercise. Clinical Trial Registration URL: upload.umin.ac.jp . Unique identifier: UMIN 000028237.