The value of the addition of β-blockers to coronary vasodilator therapy in the treatment of patients with unstable angina at rest is controversial. We conducted a double-blind, randomized, placebo-controlled 4 week trial of propranolol in 81 patients with unstable angina, 39 of whom were assigned to placebo and 42 of whom received propranolol in a dose of at least 160 mg daily. All patients were also treated with coronary vasodilators, including 80 mg nifedipine daily and long-acting nitrates. The incidences of cardiac death, myocardial infarction, and requirement for bypass surgery or coronary angioplasty did not differ between the two groups (propranolol = 16; placebo = 18). The propranolol group had a lower cumulative probability of experiencing recurrent resting angina than the placebo group (p = .013), and over the first 4 days of the trial the mean number of clinical episodes of angina (propranolol 0.9 ± 0.2, placebo 1.8 ± 0.3, p = .036), duration of angina (propranolol 15.1 ± 4.3 min, placebo 38.1 ± 8.4, p = .014), and nitroglycerin requirement (propranolol 1.1 ± 0.3 tablets, placebo 3.5 ± 0.8, p = .003) were also fewer. Continuous electrocardiographic recording for ischemic ST segment changes revealed fewer daily ischemic episodes in the propranolol group (2.0 ± 0.5) than in the placebo group (3.8 ± 0.7, p = .03), and a shorter duration of ischemia (propranolol 43 ± 10 min, placebo 104 ± 28 min, p = .039). Thus propranolol, in patients with unstable angina, in the presence of nitrates and nifedipine is not detrimental and reduces the frequency and duration of symptomatic and silent ischemic episodes.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine
- Physiology (medical)