Relationships between changes in left ventricular mass and in clinic and ambulatory blood pressure in response to antihypertensive therapy

OBJECTIVE: To analyse the relationships between changes in left ventricular mass in response to 6-month antihypertensive therapy and changes in conventional and automated measurements of clinic blood pressure, average 24 h ambulatory blood pressure and daytime and night-time blood pressures. DESIGN: After a placebo run-in period, patients with essential hypertension (World Health Organization stages I-II) were treated for 6 months with one or a combination of two first-line antihypertensive drugs. METHODS: Investigations included echocardiography, conventional and automated clinic blood pressure measurements and ambulatory blood pressure monitoring. Daytime and night-time blood pressures were assessed according to two clock-time-dependent and two clock-time-independent methods, with a wide and a narrow approach for each technique. RESULTS: Fifty-four patients completed the 6-month treatment period. Left ventricular mass, adjusted for sex and body size, was correlated significantly to systolic and diastolic clinic blood pressures, both before (r = 0.57 and r = 0.48, P < 0.001) and during antihypertensive therapy (r = 0.43, P < 0.001 and r = 0.27, P < 0.05). Changes in left ventricular mass were significantly related to changes in blood pressure. The correlation coefficients amounted to 0.39 (P < 0.01) and 0.40 (P < 0.01) for the conventional and automated measurements of clinic systolic blood pressures, respectively, and to 0.45 (P < 0.001) for the average 24 h systolic blood pressure; these r values were 0.27 (NS), 0.20 (NS) and 0.43 (P < 0.01), respectively, for the diastolic blood pressure. The average 24 h blood pressure added 7.4% (P < 0.05) and 6.2% (P = 0.06) to the variance of the changes in mass explained in terms of the conventional and the automated measurements of clinic systolic blood pressures, respectively, and 11.2% (P < 0.05) and 14.5% (P < 0.01) for the diastolic blood pressures. The changes in daytime and night-time blood pressures predicted the changes in left ventricular mass significantly (P < 0.01) and to a similar extent, irrespective of the analytical method. CONCLUSIONS: The treatment-induced changes in left ventricular mass were significantly related to the changes in clinic, 24 h, daytime and night-time blood pressures; the changes in 24 h ambulatory blood pressure add to the variance of the changes in left ventricular mass explained in terms of clinic blood pressure data.