Effect of propanolol on the expansion of abdominal aortic aneurysms: a randomized study

Background: This study investigated whether propanolol reduces the growth rate of small screen‐detected abdominal aortic aneurysms (AAAs). Methods: This was a prospective blinded randomized study of men with an aneurysm between 3 and 4·5 cm detected in a community‐based screening programme. Results: Some 477 patients were randomized: 256 to take propanolol 40 mg and 221 controls. The mean growth rate in the propanolol group was 0·06 (95 per cent confidence interval 0–0·14) versus 0·1 (0·02–0·19) mm in the control group ( P = 0·48). Propanolol decreased growth in 59 patients with an AAA larger than 3·9 cm (0·13 (0–0·31) versus 0·43 (0·26–0·60) mm in controls; P = 0·02). Compliance with propanolol treatment was poor: 31 per cent of the active treatment group were on beta blockers compared with 15 per cent in the control group. The growth in patients actually taking beta blockers was 0·24 (0·11–0·38) versus 0·25 (0·17–0·33) mm ( P = 0·91). Stiffness measurements did not differ significantly between patients taking beta blockers and controls. Subgroup analysis showed an increased stiffness in the patients on beta blockers (mean(s.d.) 31·1(4·2) versus 23·4(1·9) in controls in aortas larger than 3·4 cm; P = 0·057). Conclusion: Propanolol is not associated with a significant reduction in the growth of small aneurysms. Propanolol reduces the growth of aneurysms larger than 4 cm. Compliance with propanolol treatment for small aneurysms is low. Treatment of small screen‐detected aneurysms with propanolol cannot be recommended. © 2000 British Journal of Surgery Society Ltd