Antihypertensive treatment with felodipine but not with a diuretic reduces episodes of myocardial ischaemia in elderly patients with hypertension

Episodes of transient myocardial ischaemia can frequently be observed in hypertensive patients. To assess the effects of antihypertensive treatment with the calcium antagonist felodipine or the diuretic combination hydrochlorothiazidel triamterene on episodes of ischaemic-type ST-segment depression (ST-D), simultaneous ambulatory electrocardio-graphic and blood pressure (BP) monitoring was performed in 42 elderly hypertensives without manifest coronary artery disease. All patients (mean age 79 ± 6 years, office BP≥ 160/95 mmHg) were evaluated off any antihypertensive or anti-ischaemic therapy and after 3 months treatment with either felodipine or the diuretic (randomized, double-blind study) for episodes of significant ST-D (≥0.1 mV, duration ≥1 min, interval ≥1 min). The reduction in office BP and daytime ambulatory BP was similar for both agents, as was a significant reduction in the heart rate × systolic BP product (DP) over 24 h (felodipine: 12 441 ±2076 vs 11 643 ± 1953 mmHg. min−1; P=0.048; diuretic: 12 366 ± 2782 vs 11 062 ± 2012 mmHg. min−1; P=0.003). While felodipine significantly decreased the total number of ST-D (from 40 to six episodes; P=0.03), the total number of ST-D remained unchanged with the diuretic (non-significant increase from 31 to 45 episodes; P=0.24). The same trend was observed for the number of patients with ST-D. The ischaemic threshold, defined as DP at the onset of the episodes of ST-D, increased with felodipine (12 171 ±340 vs 13 770 ± 138 mmHg. min−1) and decreased with the diuretic (16 210 ±312 vs 14 092 ± 319 mmHg. min−1). In conclusion, antihypertensive treatment with felodipine reduces blood pressure and episodes of transient myocardial ischaemia in elderly hypertensive patients, while hydrochlorothiazidel triamterene increases these episodes despite a similar BP reduction. Felodipine may influence structural and functional factors at the coronary micro circulation level. These mechanisms improve coronary blood flow and increase the ischaemic threshold.