[Diltiazem versus intravenous nitroglycerin in the treatment of unstable angina pectoris. A randomized study]

Prognosis of unstable angina pectoris is related to admission EKG changes and prompt symptom control. The aim of this study was to compare the clinical effects of intravenous diltiazem (DTZ) or nitroglycerin (NTG) in patients with unstable angina pectoris. We studied 43 patients admitted to the hospital with a history of rest angina within the last 48 hours, associated with EKG evidence of ischemia. All subjects received intravenous heparin and oral aspirin, 23 were randomly assigned to receive intravenous DTZ and 20 to receive intravenous NTG. Both groups had similar baseline features and the endpoints of treatment were recurrence of angina, myocardial infarction, death during hospitalization and secondary side effects. Treatment with DTZ, when compared to NTG, resulted in a significant reduction of recurrent angina (8.7 and 59% respectively; p < 0.005), number of angina episodes per patient (0.18 +/- 0.5 and 0.9 +/- 1.2 respectively; p < 0.05) and lower need for dose increment to control symptoms (3 and 9 patients respectively; p < 0.05). The most common side effects observed were cephalea with NTG (60% of patients) and asymptomatic sinus bradicardia with DTZ (28% of patients). In each group, one patient had a myocardial infarction and one patient died. It is concluded that intravenous DTZ reduces myocardial ischemia to a greater extent than NTG and can be safely used in patients with unstable angina pectoris.