Captopril versus atenolol to prevent expansion rate of thoracic aortic aneurysms: rationale and design.

Thoracic aortic aneurysms are correlated with significant mortality and morbidity. No therapy, however, is effective at limiting aneurysm expansion and preventing rupture. Angiotensin-converting enzyme inhibitors can reduce the wall shear stress and inflammation, both of which play vital roles in the expansion of the aneurysm. A total of 636 patients will be randomized into one of three parallel arms, receiving captopril, atenolol or placebo. The primary end point will be the rate of change in the absolute diameter of the aortic root and ascending aorta on MRI of the aorta after 36 months. The trial will investigate the efficacy of angiotensin-converting enzyme inhibitors versus beta-blocker therapy in reducing the growth rate of thoracic aortic aneurysms and rupture. Trial registration number: NCT04224675.