Improvement in left ventricular function following successful rescue percutaneous coronary intervention is independent of time-to-reperfusion.

Objective: To study the influence of clinical and angiographic factors on global and regional left ventricular (LV) function after rescue percutaneous coronary intervention (PCI) in acute myocardial infarction (AMI).
Methods: We performed repeat cardiac catheterization in 102 patients who underwent rescue PCI at our centre. Eighty-two patients had suitable baseline and follow-up ventriculograms, which were analyzed offline by an automated edge detection technique.
Results: The mean (standard deviation [SD]) follow-up period was 22 (15) months. PCI was completed in all patients between 3 to 24 hours following the onset of pain. Improved global and regional LV systolic function was observed in 55 (67%) patients, and deterioration in 27 (33%). On univariate analysis, baseline ejection fraction (p = 0.005) and coronary stenting (p = 0.05) were associated with improved LV systolic function. Preprocedure TIMI flow, postprocedure TMP grade, time-to-reperfusion, and use of glycoprotein (GP) IIb/IIIa inhibitors did not influence LV systolic function. On multivariate analysis, ejection fraction at the time of rescue PCI (odds ratio [95% confidence interval]: 0.427 [0.234, 0.780]; p = 0.006) and stenting 3.944 (1.182, 13.156; p = 0.026) were predictors of improved LV systolic function.
Conclusion: Successful rescue PCI was associated with improved LV function at follow up in the majority of patients. Stenting, but not GP IIb/IIIa inhibitor therapy, predicted improved LV function in the area supplied by the infarct-related artery. These improvements in regional wall motion were independent of the time taken to establish reperfusion, provided the intervention was carried out between 3 to 24 hours from the onset of pain.