EFFECT OF CALCIUM-ANTAGONISTS ON EXERCISE TESTS

The aim of this study was to investigate the anti-ischemic and antianginal activity and the duration of the new dihydropyridine calcium blocker nisoldipine (NIS) in patients with stable angina pectoris. The research was carried out on 16 patients, all male, 41-68 (mean of 58) years of age, with stable angina pectoris and fixed ischemic threshold (variations <15%). After a 10-day washout period, patients were randomized to treatment with either 10 mg of nisoldipine or placebo (PL), twice daily for 21 days, according to a double-blind, crossover design. Patients underwent maximal symptom-limited exercise testing at 10 W/min on a bicycle ergometer, twice during the washout period, and once at the end of each treatment period, 3 and 12 h after oral administration of the drugs. In comparison with placebo, nisoldipine increased the ischemic threshold (N, 704 +/- 45 s: PL, 548 +/- 35 s; p < 0.01) and anginal threshold (N, 766 +/- 44 s; PL, 699 +/- 42 s; p < 0.01) for at least 12 h, and the ST-segment depression significantly decreased at maximal work (PL, 2.4 +/- 0.1 mm; N, 1.8 +/- 0.2 mm; p < 0.01) and at maximal common work (PL, 2.4 +/- 0.1 mm; N, 1.15 +/- 0.2 mm; p < 0.01). Similar to placebo the rate-pressure product was not significantly changed at higher submaximal effort after N, but it was significantly increased at the level of ischemic threshold, suggesting an increase in coronary blood flow to ischemic zones. Nisoldipine possesses anti-ischemic and antianginal activity lasting at least 12 h. This activity seems to be due to an increase in coronary blood flow to ischemic zones.