Monitoring of Antihypertensive Therapy for Reduction in Left Ventricular Mass

Abstract

Pressure pulse waveform features may predict treatment-induced regression of left ventricular (LV) mass better than casual brachial blood pressure (BP). We compared predictive power for LV mass reduction between the putative optimal pulse waveform feature (pulse amplification) and the putative optimal brachial cuff measurement (self BP monitoring at home). Forty-three patients with hypertension received standard medical treatment for 1 year. Self BP monitoring was used to determine home morning and evening BPs. Radial pressure waveforms recorded with applanation tonometry in the clinic were transformed to aortic waveforms, and pulse amplification (upper limb pulse pressure/central pulse pressure) was calculated. Antihypertensive therapy significantly (P < .05) reduced LV load, manifest by a decrease in both home BPs and by an increase in amplification. These changes were accompanied by significant reduction in echocardiographically determined LV mass index (LVMI). However, treatment-induced LVMI change did not correlate with change in any component of home BPs, but closely correlated with change in amplification (r = -0.54, P < .001). Amplification was a strong determinant of LVMI reduction, independent of age, gender, and home BP. Estimated subject numbers required for predicting a significant LVMI reduction were far less when the pulse waves were used rather than home BP; for alpha = 0.05 and beta = 0.20, numbers were 25 subjects for amplification but more than 1000 for home BP. Regression of LV mass is closely associated with reduction in wave reflection, and can be assessed more precisely and easily from radial tonometry than use of the brachial cuff measurement, even in the home setting.