Treatment of silent ischemia in unstable angina: A randomized comparison of sustained‐release verapamil versus metoprolol

Silent ischemia is a frequent finding in patients with unstable angina and portends a poor prognosis. We compared the efficacy of sustained-release (SR) verapamil and metoprolol in reducing silent ischemia in patients with unstable angina and assessed whether detection of silent ischemia was related to unfavorable outcomes in the contemporary setting of concurrent therapy with heparin and aspirin. Holter monitoring (leads a VF, V2, V5) for the first 72 h was used to assess the frequency and duration of ST-shift episodes. There were 37 patients in the verapamil-SR group and 40 patients in the metoprolol group, with both groups having similar baseline characteristics. There were more episodes of angina in the verampamil-SR group (29 vs. 12, p = 0.05). There was no difference between the two groups in the frequency (51 vs. 49 episodes, p = 0.9) or duration (23 +/- 48 vs. 18 +/- 50 min, p = 0.6) of ST-shift episodes. There were 20 unfavorable in-hospital outcomes distributed equally between the two groups (p = 0.9). Patients with unfavorable outcomes had ST shift more often (50 vs. 28%, p = 0.07) and for a longer duration (40 +/- 69 vs. 13 +/- 38 min, p = 0.03). Patients with ST shift > or = 60 min had a 60% probability of unfavorable outcome compared with 33% for ST shift of 1-59 min duration and 20% for no ST shift (p = 0.04). We conclude that metoprolol appears to reduce symptoms better than verapamil-SR, but no difference in silent ischemia or unfavorable outcomes was seen. Silent ischemia remains a common occurrence in these patients despite heparin and aspirin therapy and its detection continues to have prognostic value.