Impact of microvascular integrity and local viability on left ventricular remodelling after reperfused acute myocardial infarction.

OBJECTIVE To assess left ventricular remodelling in patients with reperfused acute myocardial infarction and to study its relation to microvascular damage. PATIENTS 25 patients successfully treated by primary percutaneous coronary angioplasty for acute myocardial infarction. SETTING University hospital METHODS Indexed end diastolic (EDVi) and end systolic (ESVi) volumes were assessed on admission and repeated at days 1 and 8. Coronary flow reserve (CFR) was assessed in the infarct related artery on day 1. Myocardial blood volume was assessed on admission and at day 8 by myocardial contrast echocardiography. In patients who manifested persistent myocardial dysfunction at hospital discharge (n = 21), local inotropic reserve was assessed by dobutamine echocardiography at day 7. RESULTS On admission, patients with and without local viability had similar EDVi and ESVi (EDVi 67 (9) and 73 (14) ml/m(2), respectively; ESVi 34 (8) and 40 (11) ml/m(2), respectively; NS). EDVi increased to 97 (22) ml/m(2) in patients without local viability (p < 0.01 v admission) but remained unchanged at 70 (11) ml/m(2) in patients with viable myocardium (NS v admission). For pooled patient data, the percentage change in EDVi correlated with CFR (r = 0.76, p < 0.0001) and myocardial blood volume in the infarct territory (r = 0.80, p < 0.0001). CONCLUSION Left ventricular dilatation may preferably occur in patients without local viability and is correlated with early CFR and extent of myocardial blood volume in the infarct territory.