Differential effects of antihypertensive drug therapy on arterial compliance

Abstract

Although vascular compliance, ΔV/ΔP, is abnormal in essential hypertension and can be improved by antihypertensive drug therapy, it is not clear whether drug-induced changes in compliance are attributable solely to lower achieved blood pressure (BP), and thus equally likely with different drugs possessing similar antihypertensive efficacy. Therefore, we used computerized arterial pulse waveform analysis (CAPWA) to measure capacitive (C1) and oscillatory (C2) components of arterial compliance in essential hypertensive subjects ( n = 39) before, and 1 and 3 months after achieving normotensive BP values with administration of either dihydropyridine calcium channel antagonists (CaBl, n = 11), converting enzyme inhibitors (CEI, n = 9), angiotensin receptor blockers (ARB, n = 9), or β-blockers (BBl, n = 10). Despite equivalent effects on BP (CaBl: −19 ± 4/−15 ± 2 mm Hg; CEI: −12 ± 3/−13 ± 2 mm Hg; ARB: −10 ± 3/−12 ± 2 mm Hg; and BBl: −14 ± 3/−12 ± 2 mm Hg; P < .005 for each drug v pretreatment), CaBl, CEI, and ARB significantly increased arterial compliance (CaBl: %ΔC1 = 30.0 ± 5.8, %Δ C2 = 43.7 ± 23.3; CEI: %ΔC1 = 32.7 ± 5.4, %ΔC2 = 26.7 ± 7.1; ARB: %ΔC1 = 36.3 ± 11.8, %ΔC2 = 43.6 ± 23.1; P < .01 for CaBl, CEI, and ARB v pretreatment), but BBl did not (%ΔC1 = −3.9 ± 7.6, %ΔC2 = −7.0 ± 11.5, P = not significant v pretreatment, sig = 0.01 v other drugs). We conclude that for an equivalent effect on BP, arterial compliance improves after therapy with some, but not all antihypertensive drugs. We hypothesize that a greater clinical benefit may result from the preferential use of drugs that concomitantly improve arterial compliance.