Cardioselective beta-blockade with metoprolol in rest angina: a randomized, double-blind, placebo-controlled,...

The antiischemic effects of the beta-1 selective beta-blocker metoprolol were studied in 9 hospitalized patients with rest angina in a double-blind, placebo-controlled, cross-over study. After 3 days of placebo treatment, the patients were randomized to metoprolol 100 mg or placebo bid for 2 days, followed by 2 days on the alternative treatment. During the last 24 hours of each period, Holter monitoring was performed. The patients marked angina attacks and NTG consumption on diary cards. Metoprolol significantly reduced the mean number of ST-changes (run-in: 5.7 +/- 0.6; metoprolol: 2.2 +/- 0.9; p = 0.013), the mean maximal ST-change during the attacks (run-in: 3.0 +/- 1.2 mm; metoprolol: 1.5 +/- 0.4 mm; p = 0.015), the mean duration of the ST-changes (run-in: 7.0 +/- 0.6 min; metoprolol: 3.2 +/- 1.0 min; p = 0.015), and the total ischemic time/24 (run-in: 41.1 +/- 7.6; metoprolol: 13.1 +/- 7.2 min; p = 0.008). None of these parameters was modified by placebo. However, the difference between metoprolol and the randomized placebo did not reach statistical significance. Metoprolol also reduced the number of chest pain attacks (p = 0.008), the duration of the attacks (p = 0.051), the severity score of the attacks (p = 0.008), and NTG consumption (p = 0.018) with respect to the run-in period. Six of the patients showed marked improvement on metoprolol while 3 showed only slight improvement or no change. No patients experienced worsening of angina or ST-changes.(ABSTRACT TRUNCATED AT 250 WORDS)