Determinants of left ventricular systolic function after acute myocardial infarction: the role of residual myocardial ischaemia

Background: Left ventricular systolic function (LVSF) is one of the major d eterminants of survival after acute myocardial infarction (AMI). Some facto rs such as the infarct size and localization, and the patency of the infarc t-related artery are known determinants of LVSF. However, the long-term eff ect of myocardial ischaemia on LVSF has been poorly studied in clinical set tings. Objectives To assess the acute and long-term effects of myocardial ischaemi a on LVSF in patients recovering from an AMI. Methods A cohort of 74 patients recovering from AMI was studied. Myocardial ischaemia was detected by means of ambulatory electrocardiogram (ECG) moni toring at recruitment (4 +/-2 days after AMI), exercise ECG test and stress echocardiography at discharge (7 +/-4 days after AMI). LVSF was studied by means of two-dimensional echocardiography at recruitment, at discharge, an d at 1,3, 6 and 12 months after AMI. Results Patients with myocardial ischaemia on ambulatory ECG monitoring and stress echocardiography had worse LVSF at recruitment than those without i schaemia. The presence of myocardial ischaemia on ambulatory ECG monitoring was an independent determinant of LVSF at recruitment, together with infar ct localization and size (assessed by creatine kinase MB isoenzyme (CK-MB) levels). Patients with signs of myocardial ischaemia on ambulatory ECG moni toring and stress echocardiography had a progressive left ventricular dysfu nction compared with those without ischaemia. Conclusions Residual ischaemia is an independent determinant of LVSF after AMI and its presence implied a progressive worsening of the LVSF. Because l eft ventricular systolic dysfunction is a major determinant of survival aft er AMI, its precursors, among them residual myocardial ischaemia, should be identified. Treatment of ischaemia is known to be associated with improved prognosis and improved LVSF. Coron Artery Dis 2001, 12:393-400 (C) 2001 Li ppincott Williams & Wilkins.