Left Ventricular Diastolic Function in Nigerian Patients with Essential Hypertension: A Retrospective Study to Compare Angiotensin Converting Enzyme Inhibitors, Calcium Channel Blockade or Their Combination

Background. Hypertension in blacks imposes a greater left ventricular hypertrophy, and accelerated heart failure onset. We evaluated and compared the echocardiographically determined systolic and left ventricular diastolic functional indices in Nigerian hypertensive patients, associated with the chronic use of ACE inhibitors, Calcium channel blockers (CCB) or their combinations.

Methods. Ejection fraction -EF, intraventricular relaxation time (IVRT), E/A peak velocity ratio, E wave deceleration time] as well as the left ventricular mass index (LVMI) was undertaken among 41 Nigerian patients with essential hypertension only, on treatment for 4–6 months prior. The 41 patients (aged 59 ± 10 years, 40% females) were divided into three groups; those receiving (i) ACE inhibitors; or (ii) CCB or (iii) combination of ACEI and CCB. All the three groups had a background of diuretic treatment for optimal blood pressure control.

Results. There were no statistically significant differences in the mean LVMI or sitting blood pressure between treatment groups. E/A ratio for ACEI treatment was 1.06 ± 0.44, CCB 0.74 ± 0.19, and for ACEI + CCB 0.87 ± 0.26 (F = 3.29, P = 0.048 anova). The 95% confidence interval for the E/A ratio on ACEI was 0.8 to 1.33. The A wave duration time integral (AVVTi) were all abnormally large, but showed a significant between treatment group difference (P = 0.037, anova). The values were 21.9 ± 4.7 for ACEI, 25.3 ± 6.3 for CCB, and least at 20.1 ± 3.6 cm for the ACE + CCB combination. Similarly, the IVRT was lowest and <100 ms with ACEI + CCB being 93 ± 18 ms, ACEI 115 ± 23 ms, and CCB being 117 ± 22 ms (F = 4.92, P = 0.01, anova). The 95% CI for IVRT on ACEI + CCB was 82 to 104 ms. There were no between treatment group differences in systolic contractility, (fractional shortening or EF).

Conclusions. The results indicate that use of an antihypertensive drug regime inclusive of an ACE inhibitor (±CCB) may be associated with greater salutary effect on indices of diastolic function, (E/A > 1, lower AVVTi, IVRT < 100 ms) even in the presence of an equivalent effect on systolic function and blood pressure.