Usefulness of serum carboxy-terminal propeptide of procollagen type I in assessment of the cardioreparative ability of antihypertensive treatment in hypertensive patients

We investigated whether serum concentration of carboxy-terminal propeptide of procollagen type I (PIP), a marker of collagen type I synthesis, can be used to assess the ability of antihypertensive treatment to regress myocardial fibrosis in hypertensive patients. The study was performed in 37 patients with essential hypertension and hypertensive heart disease. After randomization, 21 patients were assigned to losartan and 16 patients to amlodipine treatment. At baseline and after 12 months, right septal endomyocardial biopsies were performed to quantify collagen volume fraction (CVF) on picrosirius red-stained sections with an automated image-analysis system. Serum PIP was measured by specific radioimmunoassay. Nineteen patients in the losartan group and 11 in the amlodipine group finished the study. Time-course changes in blood pressure during treatment were similar in the 2 groups of patients. In losartan-treated patients, CVF decreased from 5.65+/-2.03% to 3.96+/-1.46% (P