ANTIHYPERTENSIVE TREATMENT WITH FELODIPINE BUT NOT WITH A DIURETIC REDUCES EPISODES OF MYOCARDIAL-ISCHEMIA IN ELDERLY PATIENTS WITH HYPERTENSION

Episodes of transient myocardial ischaemia can frequently be observed in hypertensive patients. To assess the effects of antihypertensive tr eatment with the calcium antagonist felodipine or the diuretic combina tion hydrochlorothiazidel triamterene on episodes of ischaemic-type ST -segment depression (ST-D), simultaneous ambulatory electrocardiograph ic and blood pressure (BP) monitoring was performed in 42 elderly hype rtensives without manifest coronary artery disease. All patients (mean age 79 +/- 6 years, office BP greater-than-or-equal-to 160/95 mmHg) w ere evaluated off any antihypertensive or anti-ischaemic therapy and a fter 3 months treatment with either felodipine or the diuretic (random ized, double-blind study) for episodes of significant ST-D (greater-th an-or-equal-to 0.1 mV, duration greater-than-or-equal-to 1 min, interv al greater-than-or-equal-to 1 min). The reduction in office BP and day time ambulatory BP was similar for both agents, as was a significant r eduction in the heart rate x systolic BP product (DP) over 24 h (felod ipine: 12 441 +/- 2076 vs 11 643 +/- 1953 mmHg.min-1; P=0.048; diureti c: 12 366 +/- 2782 vs 11 062 +/- 2012 mmHg.min-1; P=0.03). While felod ipine 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 t he 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.m in-1) and decreased with the diuretic (16 210 +/- 312 vs 14 092 +/- 31 9 mmHg.min-1). In conclusion, antihypertensive treatment with felodipi ne reduces blood pressure and episodes of transient myocardial ischaem ia in elderly hypertensive patients, while hydrochlorothiazide/triamte rene increases these episodes despite a similar BP reduction. Felodipi ne may influence structural and functional factors at the coronary mic rocirculation level. These mechanisms improve coronary blood flow and increase the ischaemic threshold.