Angiotensin-converting enzyme inhibitor helps prevent late remodeling after left ventricular aneurysm repair in rats.

BACKGROUND

We reported in a previous study that the initial effects of left ventricular (LV) repair (LVR) for LV aneurysm were not long lasting. Angiotensin-converting enzyme inhibitor (ACE-I) is known to attenuate remodeling after myocardial infarction, and could be effective after LVR.

METHODS AND RESULTS

Left ventricular aneurysms were developed in rats after left anterior descending artery ligation. Rats were divided into 3 groups: sham operation with ACE-I (lisinopril 10 mg/kg/d) (n=10; group A), LVR (by plicating the LV aneurysm) with placebo (n=8; group R), and LVR with ACE-I (n=10; group RA). LV function was evaluated by echocardiography and catheterization. Oxidative stress in the myocardium was estimated by immunohistochemistry for 8-hydroxy-2'-deoxyguanosine. One week after LVR, LV end-diastolic area was smaller and fractional area change was better in the 2 LVR groups. Four weeks after LVR, LV end-diastolic area, and fractional area change deteriorated in group R but not so much in group RA; E-max was higher in group RA (0.79+/-0.20 mm Hg/mL) than in groups A (0.25+/-0.03 mm Hg/mL; P<0.01) and group R (0.27+/-0.03 mm Hg/mL; P<0.01). Oxidative stress was much lower in the 2 ACE-I groups.

CONCLUSIONS

LVR improved LV size and systolic function only in the early phase. Adjuvant use of ACE-I was useful for preventing redilation and maintaining LV systolic function, was associated with suppressed oxidative stress, and may make LVR a more effective surgical procedure for LV aneurysm.