Potential Protective Effect of Long-Term Therapy with Xuezhikang on Left Ventricular Diastolic Function in Patients with Essential Hypertension

Abstract

To investigate the benefits of long-term therapy with Xuezhikang, a cholestin extract, in combination with calcium channel blockers for improvement of left ventricular (LV) hypertrophy and function in patients with essential hypertension, as determined using echocardiography. Fifty-five (55) hypertensive patients with normal blood low-density lipoprotein cholesterol (LDL-C) levels were randomly assigned to the Xuezhikang group (n = 28, 1200 mg/d of Xuezhikang) or the placebo group (n = 27, matched placebo). All of the patients were treated with extended-release nifedipine (20 mg twice daily). Thirty (30) normotensive subjects, matched for age and gender, were selected as a control group. Conventional echocardiography and tissue Doppler imaging were used to measure the left ventricle (LV) wall thickness and LV diastolic function at weeks 0, 24, and 72 during the period of observation. The serum levels of lipids, carboxy-terminal propeptide of procollagen type I (PIP), and C-reactive protein (CRP) were determined as well. The hypertensive patients had significantly elevated PIP and CRP levels in serum, increased LV wall thickness, and impaired LV diastolic function compared with the normotensive subjects (0.01 < p < 0.05). Compared with the placebo group, the transmitral flow velocities (E/A ratio) (1.11 +/- 0.36 versus 0.85 +/- 0.24, p < 0.01) and the myocardial motion velocities (Em/Am ratio) at the septal mitral annulus (0.90 +/- 0.19 versus 0.70 +/- 0.18, p < 0.05) and the lateral mitral annulus (1.06 +/- 0.20 versus 0.86 +/- 0.14, p < 0.01) were significantly increased, while there was no significant change in the LV wall thickness after 72 weeks of therapy with Xuezhikang. The serum levels of PIP (0.43 +/- 0.13 ng/mL versus 0.51 +/- 0.20 ng/mL, p < 0.05) and CRP (0.32 +/- 0.13 mg/L versus 0.40 +/-0.17 mg/L, p < 0.05) were significantly reduced compared to placebo treatment. There was no significant correlation between changes in LV diastolic function and blood pressure or lipid profile with Xuezhikang therapy. Long-term therapy with Xuezhikang improved LV diastolic function, probably mediated through antifibrotic and anti-inflammatory effects and independent of blood pressure and lipid profiles in patients with essential hypertension.