Reverse remodeling of cardiac collagen protein expression after surgical therapy for experimental aortic stenosis.

BACKGROUND AND AIM OF THE STUDY

Reversal of myocardial collagen gene expression was examined in parallel to left ventricular reverse remodeling after surgical correction of experimental aortic stenosis.

METHODS

A standard growing sheep model (age at baseline 6-8 months) was used. Measurements were performed at baseline (point A) when inducing left ventricular hypertrophy (LVH) through supracoronary banding, at 8.3 +/- 1.0 months later at surgical correction (point B), and after another 10.1 +/- 2.0 months during final examinations (point C). Gene expression for collagen I and III was also studied.

RESULTS

Left ventricular function was stable throughout the study. The left ventricular mass index (LVMI) was 82 +/- 21 g/m2 at point A, 150 +/- 33 g/m2 at B, and 78 +/- 18 g/m2 at C (p <0.01). Myocardial fiber diameter was 11.3 +/- 0.8, 15.9 +/- 1.2 and 11.4 +/- 1 microm at points A, B and C, respectively (p <0.01). Protein expression for collagen I was 0.71 +/- 0.2 (at A), 1.13 +/- 0.3 (at B) and 0.85 +/- 0.4 (at C) (p <0.01), while that for collagen III was 0.72 +/- 0.4 (at A), 1.26 +/- 0.8 (at B) and 0.83 +/- 0.3 (at C) (p <0.01). There was a significant correlation between changes in LVMI and myocardial collagen expression.

CONCLUSION

Complete reverse remodeling with regression of LVH and myocardial collagen protein expression can be anticipated after surgical correction of experimental aortic stenosis.