Efficacy of diltiazem in variant angina. Results of a double-blind crossover study in CCU by Holter monitoring. The possible occurrence of a withdrawal syndrome.
The short and long term efficacy of diltiazem, a calcium-entry blocker, has been evaluated in a group of ten patients with Prinzmetal's variant angina admitted to a CCU. In the short term part of the study, after a run-in period, diltiazem 60 mg tid and placebo were administered alternatively during 4 randomized 72 hour periods. Response was assessed using continuous Holter monitoring, measuring the frequency of transient ischemic attacks. During the run-in period the number of episodes/day/patient was 16.1. No episodes of transient ST segment elevation were recorded during both periods of diltiazem treatment in 3 patients and during one of the two periods in 4. For the group as a whole the number of episodes during the first placebo period was not statistically different from that during the run-in period (208 versus 161). No statistically significant difference was also found in 8 patients comparing the number of episodes during the second placebo period and the run-in period (166 versus 101). During each period of diltiazem treatment an highly significant reduction in the number of episodes was observed (43 and 5, p = .006 and p = .02). Two patients did not complete the study protocol. Both patients had a worsening of angina during the first placebo period following diltiazem treatment. One of them developed an acute myocardial infarction. The possible occurrence of a rebound phenomenon after withdrawal of diltiazem seems to be indicated, in 6 patients, by a significant increase in the number of ischemic episodes recorded during the placebo period following active treatment in respect to the number during the first placebo period (159 versus 73, p = .04).(ABSTRACT TRUNCATED AT 250 WORDS)
D000368:Aged; D000788:Angina Pectoris, Variant / Q000188:drug therapy*; D004110:Diltiazem / Q000008:administration & dosage / Q000627:therapeutic use*; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004562:Electrocardiography; D004992:Ethics, Medical; D005080:Exercise Test; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D011897:Random Allocation; D012008:Recurrence
D004110:Diltiazem