940-71 Relative Importance of Acute Left Ventricular Function, Infarct Artery Patency, and Improvement of Left Ventricular Function for Late Survival After Direct Angioplasty for Acute Myocardial Infarction

Of 663 pts with acute infarction treated with direct angioplasty, 576 hospital survivors were followed 5.3 yrs (median). Late ejection fraction (EF) data were obtained in 54% of pts at 6–8 mos. There were 48 late cardiac and 37 non-cardiac deaths. Late infarct related artery (IRA) patency was 92%. Multivariate predictors of late cardiac mortality by Cox regression were acute EF (P = 0.0001), improvement in EF (P = 0.0001), prior bypass surgery (P = 0.005), and female gender (P = 0.05). Late survival was excellent in pts with acute EF ≥ 45% vs pts with acute EF l 45% (7 yr survival 89% vs 71%, P = 0.004). Patency of the IRA was not a significant predictor of late survival in pts with acute EF ≥ 45%, but was a significant univariate predictor in pts with acute EF l 45% (6 yr survival patent vs occluded: 89% vs 35%, P = 0.004). Patency was important for improvement of left ventricular function (LVF) (late improvement in EF in patent vs occluded IRA: + 4.8% vs–4.8%, P = 0.0011. Although patency was important for survival in pts with depressed LVF by univariate analysis, in a multivariate model which included both patency and improvement in EF, only improvement in EF was a significant independent predictor (P = 0.0001). Conclusion Acute LVF is the most important determinate of late survival. IRA patency is important for late survival in pts with depressed acute LVF, but this appears to be related to its effect on improvement in LVF rather than through an independent effect.