The regression of left ventricular hypertrophy by imidapril and the reduction of serum procollagen type III amino-terminal peptide in hypertensive patients

Angiotensin-converting enzyme (ACE) inhibitors are known to be the most eff ective antihypertensive drugs for reducing left ventricular mass in hyperte nsives when compared to other classes of drugs. In the pre sent study, we e valuated the effects of imidapril, an ACE inhibitor, on serum procollagen t ype III amino-terminal peptide (PIIIP) levels as well as the left ventricul ar mass index (LVMI). The subjects consisted of 15 patients (12 men and 3 w omen) in the outpatient clinic of our hospital who were diagnosed as essent ial hypertensives and who had not been treated with any antihypertensive me dication prior to the study. Left ventricular hypertrophy was observed in a ll of the patients. i.e., LVMI > 110 g/m(2) in men and > 106 g/m(2) in wome n. Blood pressure, LVMI, and serum PIIIP levels were measured before and af ter treatment with imidapril for 6 months. The starting dose of imidapril w as 5 mg, and this was increased to 10 mg. Finally, 1 mg of trichlormethiazi de was added to obtain adequate control of blood pressure. Blood pressure s ignificantly decreased in 12 patients, and the mean LVMI decreased signific antly from 153.1 +/- 9.0 to 135.4 +/- 6.3 (p < 0.01) after treatment. The c hanges in LVMI and PIIIP levels with treatment had significant correlation (r = 0.639, p < 0.05). The present study showed that imidapril reduces the left ventricular mass in hypertensives after 6 months of treatment, and tha t this may at least in part be due to a decrease in the collagen content of the hypertrophied heart, suggesting that serum PIIIP levels are a useful m arker of the regression of left ventricular hypertrophy.