Background: Diastolic dysfunction might represent an important pathophysiological intermediate between hypertension and heart failure. Our aim was to determine whether inhibitors of the renin-angiotensin-aldosterone system, which can reduce ventricular hypertrophy and myocardial fibrosis, can improve diastolic function to a greater extent than can other antihypertensive agents.
Methods: Patients with hypertension and evidence of diastolic dysfunction were randomly assigned to receive either the angiotensin receptor blocker valsartan (titrated to 320 mg once daily) or matched placebo. Patients in both groups also received concomitant antihypertensive agents that did not inhibit the renin-angiotensin system to reach targets of under 135 mm Hg systolic blood pressure and under 80 mm Hg diastolic blood pressure. The primary endpoint was change in diastolic relaxation velocity between baseline and 38 weeks as determined by tissue doppler imaging. Analyses were done by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00170924.
Findings: 186 patients were randomly assigned to receive valsartan; 198 were randomly assigned to receive placebo. 43 patients were lost to follow-up or discontinued the assigned intervention. Over 38 weeks, there was a 12.8 (SD 17.2)/7.1 (9.9) mm Hg reduction in blood pressure in the valsartan group and a 9.7 (17.0)/5.5 (10.2) mm Hg reduction in the placebo group. The difference in blood pressure reduction between the two groups was not significant. Diastolic relaxation velocity increased by 0.60 (SD 1.4) cm/s from baseline in the valsartan group (p<0.0001) and 0.44 (1.4) cm/s from baseline in the placebo group (p<0.0001) by week 38. However, there was no significant difference in the change in diastolic relaxation velocity between the groups (p=0.29).
Interpretation: Lowering blood pressure improves diastolic function irrespective of the type of antihypertensive agent used.