Purpose: Animal and human studies have suggested that beta-blockade may decrease the growth rate of aneurysms. We investigated whether propranolol decreases the growth rate of small abdominal aortic aneurysms (AAAs).
Methods: We randomly assigned patients with an asymptomatic AAA between 3.0 and 5.0 cm to receive either a placebo (n = 272) or propranolol (n = 276) in a double-blind fashion. Patients were observed for a mean of 2.5 years. The primary end point was the mean annual growth rate as determined by means of ultrasound scanning performed every 6 months. Secondary outcomes were death, surgery, withdrawal from study medication, and quality of life measured by means of the Short-form Health Survey (SF-36). The main analyses were performed by means of intention to treat.
Results: The two groups were similar at baseline: 84% were men with a mean age of 69 years and a mean AAA size of 3.8 cm. Fewer patients in the placebo group stopped their study medication (26.8% vs 42.4%; P =.0002). The annual growth rate was similar in the two groups (placebo, 0.26 cm/y vs propranolol 0.22 cm/y; P =.11). There was a trend toward more elective surgery in the placebo group (26.5% vs 20.3%; P =.11), but there was no difference in death rate (placebo, 9% vs propranolol, 12%; P =.36). Patients in the propranolol group had significantly poorer quality of life scores in the physical functioning, physical role, and vitality dimensions of the SF-36.
Conclusion: Patients with AAAs do not tolerate propranolol well, and the drug did not significantly affect the growth rate of small AAAs.