Little is known about collagen metabolism in heart failure, with or without left ventricular systolic dysfunction. We studied serum concentrations of the carboxy-terminal propeptide of procollagen type I (PIP), a marker of collagen type-I synthesis, and of the carboxy-terminal telopeptide of collagen type I (ICTP), a marker of collagen type-I degradation, in 70 patients admitted for heart failure (35 with depressed left ventricular systolic function and 35 with preserved left ventricular systolic function) and in 30 control subjects. Patients with kidney failure, liver disease, metabolic bone disease, rheumatic disease, recent (within 3 months) major trauma or surgery, or serious wounds were excluded. The concentration of the collagen synthesis marker, PIP, was higher in heart failure patients than control subjects, at 140+/-56.38 mg/L vs 113.66+/-36.6 microg/L, respectively (P=.01). However, there was no difference in the concentration of the collagen degradation marker, ICTP, between heart failure patients and control subjects, at 2.89+/-2.37 mg/L vs 2.26+/-1.7 microg/l, respectively. In heart failure patients, left ventricular systolic function had nonsignificant effect on the PIP or ICTP concentration.