Improvement of global and regional left ventricular function by percutaneous transluminal coronary angioplasty after myocardial infarction.

OBJECTIVES

This study was designed to evaluate how elective percutaneous transluminal coronary angioplasty of the infarct-related vessel after acute myocardial infarction affects global ejection fraction and regional wall function.

BACKGROUND

The severity of the residual stenosis of the infarct-related artery after thrombolysis is an important predictor of changes in left ventricular function; however, the optimal time to restore complete perfusion in the infarct area has not been determined.

METHODS

We prospectively evaluated patients with a first myocardial infarction, postinfarction ischemia and residual high grade stenosis with reduced flow in the infarct-related artery who underwent successful coronary angioplasty. The group comprised 74 patients (61 men, 13 women with a mean age +/- SD of 55.9 +/- 9.9 years). Global ejection fraction and infarct region function (expressed as area ejection fraction) were angiographically measured before coronary angioplasty (3.9 +/- 2.1 weeks after infarction) and on routine follow-up study 6 +/- 1 months after angioplasty.

RESULTS

Restenosis with reduced flow occurred in 15 patients (20%). The global ejection fraction in patients with complete flow at follow-up increased significantly from 56.8% +/- 12% to 62.3% +/- 12.5% (p < 0.001). Regional wall motion of the infarct area increased from 12.1% to 22.5% (p = 0.001) in patients with anterior wall infarction and from 20.4% to 28.5% (p = 0.002) in those with inferior wall infarction. In patients with restenosis there was no difference at follow-up either in global ejection fraction (from 47.7% +/- 7.7% to 47.1% +/- 12.7%, p = 0.57) or in regional wall motion of the infarct area.

CONCLUSIONS

Global and regional myocardial dysfunction due to postinfarction ischemia lessens significantly after successful coronary angioplasty of the infarct-related coronary artery with long-term sustained normal, complete flow. In contrast, restenosis with reduced flow prevents long-term improvement of left ventricular function.