Abstract 2746: Left Ventricular Diastolic Function Assessed By Tissue Doppler Echocardiography Is Impaired By β-blocker + Diuretic-based Therapy Compared With Calcium Antagonist + Ace Inhibitor-based Therapy: An ASCOT Substudy.
Background: Different anti-hypertensive therapies may vary in their effect on left ventricular diastolic function. The Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) randomized patients to β-blocker (atenolol) + diuretic (bendroflumethiazide-K)-based therapy (BB/D) or calcium antagonist (amlodipine) + ACE inhibitor (perindopril)-based therapy (CA/ACEI). We compared left ventricular diastolic function in the two treatment groups.
Methods: Echocardiography including Tissue Doppler Imaging was performed on 977 subjects at two centres participating in ASCOT (St Mary’s Hospital, London, UK & Beaumont Hospital, Dublin, Eire) to assess left ventricular diastolic function after 12 months of treatment. Data are means (SD).
Results: Systolic blood pressure (SBP) was similar in both treatment groups (BB/D = 137(17), CA/ACEI = 136(14); p = 0.3), but heart rate was significantly lower in BB/D group (BB/D = 57(10), CA/ACEI = 73(12); p<0.001). Ejection fraction did not differ between groups (BB/D = 69.5 (11.3)%, CA/ACEI = 69.2 (12.2)%, p = 0.8), but early diastolic mitral annular velocity (E’), a measure of diastolic relaxation, was significantly lower in BB/D group (BB/D = 7.9(1.8), CA/ACEI = 8.8 (2.0); p <0.001). E/E’, a measure of left ventricular filling pressure, was also significantly higher in BB/D group (8.1 (2.4) vs. 7.8 (2.1), p=0.01). Differences in E’ or E/E’ remained highly significant (<0.001) after adjustment for covariates (age, sex, fasting plasma glucose, body mass index and cholesterol). Further adjustment for SBP and heart rate had no impact on differences in mean E’ (p<0.001), but differences in E/E’ were attenuated.
Conclusions: BB/D based therapy is associated with impaired diastolic function compared with CA/ACEI therapy. Differences in the effect of anti-hypertensive therapy on diastolic function could influence the risk of heart failure and other cardiovascular events in hypertensive patients with preserved systolic function.