A multicenter, randomized clinical trial of intravenous diltiazem in treatment of unstable angina
Zhonghua Xin Xue Guan Bing Za Zhi 33(3): 238-242
2005
ISSN/ISBN: 0253-3758 PMID: 15929820 Document Number: 589516
Objective To investigate the clinical efficacy and safety of intravenous diltiazem compared with nitroglycerin in the patients with unstable angina pectoris. Methods A multicenter, randomized, open-lable, parallel group trial was conducted. A total of 213 eligible patients were enrolled. They were randomized either to diltiazem or nitroglycerin treatment. The diltiazem was administered from 100 mu g/min at the initiation of treatment, the largest dosage was 200-300 mu g/min; the nitroglycerin was administered from 20 mu g/min at the initiation of treatment. The largest dosage was 80-100 mu g/min. Intravenous infusion was kept over 48 hours. The endpoints included refractory angina pectoris, acute myocardial infarction, death, emergency PTCA and CABG. Results ( I) Intravenous diltiazem was effective on the improvement of symptom and electrocardiogram, and its effects were similar to intravenous nitroglycerin. (2) Compared with nitroglycerin, intravenous diltiazem lowered heart rate and myocardial oxygen consumption index (systolic pressure x heart rate) to more extent significantly. ( 3)After treatment, the onsets of refractory angina pectoris were reduced more significantly in the diltiazem group than in nitroglycerin group[4(3.8%) vs13 (11.9%, RR 0.32 (95% CI 0.11-0.96), P < 0. 05]. (4) The patients whose heart rate were reduced significantly (<= 50 beats per minute) in the diltiazem group were more than in the nitroglycerin group[8(7.7%) vs 0 (0%), P < 0.01]. But these patients could tolerate the lower heart rate very well in the diltiazem group. (5) The needs of beta receptor blocker or calcium antagonists were reduced more significantly in the diltiazem group compared with those in the nitroglycerin group[2(1.9%) vs 13 (11.9%) P < 0.01]. Conclusion Intravenous diltiazem therapy is effective and safe for patients with unstable angina pectoris. It may significantly lower the risk of refractory angina pectoris compared with intravenous nitroglycerin.