Early patency of she infarct-related artery after myocardial infarction preserves diastolic filling

A patent infarct-related artery (IRA) following myocardial infarction has b een associated with lower mortality, increased systolic function, decreased left ventricular remodeling, and electrical stability. The purpose of this study was to determine whether coronary artery patency early after myocard ial infarction is associated with greater early diastolic filling than a cl osed artery. Radionuclide ventriculograms were performed at a central labor atory on 167 patients who received alteplase for an acute myocardial infarc tion and had infarct artery potency determined by cardiac catheterization. The peak early filling rate (PEFR) was assessed by 4 different methods: (1) PEFR (EDV/s)-normalized to the end-diastolic volume; (2) PEFR (SV/s)-norma lized to the stroke volume; (3) PEFR (ml/s/m(2))-an absolute diastolic fill ing rate; and (4) PEFR (PER)-normalized to the peak ejection rate. Patients with a closed IRA (n = 16, Thrombolysis In Myocardial Infarction [TIMI] 0 or 1 few) and patients with an open IRA (n = 151, TIMI 2 or 3 flow) had sim ilar ages, ejection fractions, and cardiac volumes. However, among patients with an occluded IRA, the PEFR was decreased by 12% to 18% by the 4 measur es of diastolic filling (3 of 4 methods, p <0.05). PEFR (EDV/s) was 1.69 <p lus/minus> 0.9 in the occluded group versus 2.06 +/- 0.4 EDV/s in the open artery group (p = 0.005). By multivariate analysis, IRA potency was an inde pendent predictor of the PEFR by all 4 methods. Early coronary artery poten cy after an acute myocardial infarction preserves diastolic filling. Improv ed diastolic function may in past explain part of the long-term benefits of a patent IRA after thrombolytic therapy when there is no documented improv ement in the ejection fraction. (C) 2001 by Excerpta Medico, Inc.