Correlation of myocardial interstitial collagen in the right ventricular septum with ventricular function of patients with ischemic cardiomyopathy.

Background: Myocardial collagen content influences ventricular relaxation, contraction, and morphology. Its relationship with ventricular function in patients (Pts) with ischemic cardiomyopathy (ICMP) has not yet been fully studied in humans.

Objective: To assess the relationship between interstitial collagen content in non-infarcted areas of the right ventricular septum and ventricular function in ICMP.

Methods: 31 pts with coronary artery disease were divided into four groups as follows:The control group consisted of 7 pts with normal left (LVEF) and right (RVEF) ventricular ejection fraction (group C); Group 1: 5 patients with RVEF < 40%; Group 2: 9 pts with LVEF < 40%; and Group 3, 10 pts with biventricular dysfunction. RVEF and LVEF were measured by radionuclide angiography. For quantitative analysis of interstitial collagen volume fraction (CVF), endomyocardial biopsy specimens were taken from the right ventricle and stained with picrosirius red.

Results: Mean CVF was significantly higher in group 3, compared with the control group and with groups 1 and 2 (30.2 +/- 7.9% vs. 6.8 +/- 3.3% vs. 15.8 +/- 4.1% vs. 17.5+/-7.7%, respectively; p =0.0001). It was also significantly higher in patients belonging to group 2, compared with those in the control group (17.5 +/- 7.7% vs. 6.8 +/- 3.3%, p =0.0001). CVF was inversely correlated with RVEF (r = - 0.50, p = 0.003) and LVEF (r = -0.70, p = 0.0001).

Conclusion: In ICMP, CVF is elevated in non-infarcted areas of the right ventricular septum and inversely correlated with right and left ventricular function.