Time course and determinants of left ventricular function recovery after primary angioplasty in patients with acute myocardial infarction

OBJECTIVES We sought to evaluate the importance of time in relation to trea tment, time course and determinants of recovery of left ventricular (LV) fu nction in patients with acute myocardial infarction (AMI) undergoing primar y percutaneous transluminal coronary angioplasty (PTCA). BACKGROUND Myocardial salvage has been shown to be dependent an the time el apsed fram the onset of AMI to reperfusion. METHODS Left ventricular function was evaluated at hospital admission, afte r angioplasty, at 24 h and 6 months by both echocardiography and angiograph y and at 1, 7, 30, 90 and 180 days by echocardiography in 101 consecutive p atients. RESULTS Patients were allocated to three groups according to interval betwe en symptom onset and angioplasty: <2 h (group A), 2 to 4 h (group B) and >4 h (group C). Patients in groups A and B showed a progressive improvement o f LV function between day 7 and day 90, which became statistically signific ant at day 30 (p < 0.01). No LV function changes were noted in group C pati ents. Thrombolysis In Myocardial Infarction (TIMI) flow grade <3 at 24 h wa s not associated with any significant change in LV volume and function duri ng the six-month follow-up period. Restenosis, when associated with TIMI fl ow grade 3 in the infarct-related vessel, did not influence LV function. Fl ow grade <3 of the infarct-related artery was not associated with any impro vement of cardiac events independently from the time to treatment at the in itial procedure. CONCLUSIONS Patients undergoing primary PTCA for AMI have a good recovery o f LV function if TIMI flow grade 3 is restored within 4 h. Coronary angiopl asty limits further remodeling of the LV in patients treated after 4 h. (J Am Coll Cardiol 2001;38:464-71) (C) 2001 by the American College of Cardiol ogy.