Diltiazem slow release and left ventricular hypertrophy: A volumetric approach of left ventricular mass using magnetic resonance imaging

Aims: This study was designed to assess the changes in left ventricular mass (LVM) in hypertensive patients with left ventricular hypertrophy under drug therapy with once-daily slow-release diltiazem. Magnetic resonance imaging (MRI) was used for this purpose because of its higher reproducibility than M-mode or two-dimensional echocardiography. Methods: Patients suffering from essential hypertension were included if their baseline LVM index (LVMI) was greater than or equal to 105g/m(2) in male or greater than or equal to 85g/m(2) in female patients, ie, equal or higher to the median values observed in hypertensive patients in our institution. MRI consisted in a true short-axis, electrocardiogram (ECG) gated spin-echo slice acquisition at baseline, after 3 and 6 months of therapy (M-0, M-3, and M-6). Data were stored on magnetic tapes and read subsequently under blind conditions and the control of an external auditor. Results: Thirty-five patients were included, of these, 14 patients (40%) were not previously treated. Inter- and intra-observer variability for LVMI measurement were 5.6 +/- 4.3% and 2.1 +/- 3.0%, respectively. Mean baseline LVMI was 110 +/- 16 g/m(2) in male and 96 +/- 16 g/m(2) in female patients. It decreased by 3.6% at M-3 (P = 0.05) and by 6.0% at M-6 (P = 0.02). A trend towards a greater LVMI reduction was observed in previously untreated patients. Conclusion: This study confirms that MRI is a reproducible technique for the measurement of LVM. It demonstrates a significant reduction in LVMI as early as the 3rd month of therapy in hypertensive patients treated with once-daily sustained release (SR) diltiazem, although baseline LVMI in the majority of participating patients was only moderately increased.