Low molecular weight heparin versus regular heparin or aspirin in the treatment of unstable angina and silent ischemia.

OBJECTIVES: This study was designed to test the hypothesis that low molecular weight heparin may lessen the severity of ischemic events in patients with unstable angina. BACKGROUND: Unstable angina is a thrombotic process that requires intensive medical treatment. Although current treatments can reduce the number of complications, serious bleeding continues to occur. Nadroparin calcium, a low molecular weight heparin, seems to be a safe therapeutic agent that does not require laboratory monitoring. METHODS: A total of 219 patients with unstable angina entered the study at a mean time of 6.17 h after the last episode of rest pain. Patients were randomized to receive aspirin (200 mg/day [group A]), aspirin plus regular heparin (400 IU/kg body weight per day intravenously and titered by activated partial thromboplastin time [group B]) and aspirin plus low molecular weight heparin (214 UIC/kg anti-Xa twice daily subcutaneously [group C]). The major end points determined for the in-hospital period were 1) recurrent angina, 2) myocardial infarction, 3) urgent revascularization, 4) major bleeding, and 5) death. Minor end points were 1) silent myocardial ischemia, and 2) minor bleeding. Event rates were tested by chi-square analysis. RESULTS: Recurrent angina occurred in 37%, 44% and 21% of patients in groups A, B and C, respectively, and was significantly less frequent in group C than in either group A (odds ratio 2.26, 95% confidence interval [CI] 1 to 5.18, p = 0.03) or group B (odds ratio, 3.07, 95% CI 1.36 to 7.00, p = 0.002). Nonfatal myocardial infarction was present in seven patients in group A, four in group B and none in group C (group B vs. A, p = 0.5; group C vs. A, p = 0.01). Urgent revascularization was performed in nine patients in group A, seven in group B and one in group C (C vs. A, p = 0.01). Two episodes of major bleeding occurred in group B. Silent myocardial ischemia was present in 38%, 41% and 25% of patients in groups A, B and C, respectively, and was significantly less frequent in group C than group B (odds ratio 2.12, 95% CI 0.97 to 4.69, p = 0.04). Minor bleeding was detected in 10 patients in group B, 1 patient in group C (B vs. C, p = 0.01) and no patient in group A (A vs. B, p = 0.003). CONCLUSIONS: In this study, treatment with aspirin plus a high dose of low molecular weight heparin during the acute phase of unstable angina was significantly better than treatment with aspirin alone or aspirin plus regular heparin.

ST-segment computerized monitoring before and after angioplasty: clinical correlation with recurrent angina during the short-term follow-up.

The purpose of this study was to determine whether computerized ST-segment monitoring previous to percutaneous transluminal coronary angioplasty (PTCA) and after performance of this procedure may be useful to discern a pattern of recurrent angina. For this purpose, we analyzed 57 patients (11 women and 46 men, mean age 60 years) before and after treatment with balloon procedure. These patients were followed up during the next 3 months. A computerized electrocardiographic (ECG) device was used which was capable of recording simultaneously all 12 leads at rest. It was programmed to store a complete ECG every 5 min and was capable of detecting any abnormal ST alteration > than 0.5 mV at 80 ms after J junction, including R-wave amplitude. Measurements were started before (mean time 7.26 h) and after (mean time 7.96 h) the procedure. The value for ST amplitude at the J junction was used as the 0 point; then the most negative depression or the most positive elevation value was considered as the most abnormal ST alteration during monitoring. The patients were followed up for 3 months for the purpose of recognizing recurrent angina or establishing the occurrence of death. Twelve patients (30%) had recurrent angina. Discriminant function analysis revealed that ST monitoring in these patients showed significant difference after PTCA in comparison with controls, both in the frontal plane [ST depression 170 +/- 52 mV vs. 231 +/- 23 (p = 0.02)] and in precordial leads [176 +/- 16 vs. 80 +/- 6.19 mV (p = 0.0001)].(ABSTRACT TRUNCATED AT 250 WORDS)