Blood Pressure Control Determines Improvement in Diastolic Dysfunction in Early Hypertension

BACKGROUND: Diastolic dysfunction is common in early hypertension. We hypothesized that improvement in diastolic dysfunction is blood pressure (BP) dependent and may occur early with treatment in newly diagnosed untreated hypertensive patients. METHODS: Forty untreated hypertensive subjects (age 52 +/- 1.4 years, mean +/- s.e.m.) with diastolic dysfunction based on Canadian Consensus Guidelines, received either bendroflumethiazide 2.5 mg (1.25 mg for the first month), or candesartan 16 mg (8 mg for the first month). Left ventricular (LV) structure and function, early diastolic velocity (E') and systolic velocity, and systolic myocardial velocity (Sm) were assessed echocardiographically using M-mode, 2-dimensional, and tissue Doppler imaging (TDI) before and at 1 and 3 months following treatment. RESULTS: Antihypertensive treatment reduced BP significantly at 3 months (168 +/- 2/97 +/- 1-143 +/- 2/86 +/- 1 mm Hg, P < 0.0001). Both drugs had similar and significant effects on TDI E' which increased from 7.8 +/- 0.2 to 10 +/- 0.3 cm/s (P < 0.001). The improvement in TDI E' was independent of LV mass index (LVMI) regression but was significantly related to the improvement in Sm (r = 0.73, P < 0.0001) and the fall in systolic BP (R = 0.51, P < 0.001). Normalization of diastolic function was associated with better control of BP (130 +/- 4/81 +/- 2 mm Hg vs. 149 +/- 2/88 +/- 1 mm Hg, P < 0.05). In a stepwise regression model, reduction in systolic BP (P < 0.001) and TDI Sm (P < 0.0001) emerged as independent determinants of improvement in TDI E' with no contribution from age, gender or change in relative wall thickness (RWT) (R(2) = 0.68, P < 0.0001). CONCLUSIONS: Achieving good BP control and enhancement in systolic function determines the improvement in diastolic function in early hypertension.