Objectives Coronary flow reserve in the non-infarcted myocardium has been reported to be impaired after the onset of myocardial infarction, however, the clinical significance of microvascular dysfunction in the non-infarcted myocardium has not fully examined. This study was designed to assess the relationship between coronary flow reserve in the remote region and left ventricular remodelling in the 6-month follow-up after acute myocardial infarction.
Methods We studied 36 patients (mean age 58.8), with single-vessel AMI treated by successful revascularisation, and 10 normal subjects (mean age 53.4). We utilised two-dimensional echocardiography (2-DE) and real-time myocardial contrast echocardiography to assess left ventricular function and coronary flow reserve 1 week after percutaneous coronary intervention, respectively. And 6 months later 2-DE was repeated. Cardial Troponin I was routinely taken to estimate the peak concentration.
Results 1 week after PCI, CFR was 2.05 in the infarcted region and 1.54 in the remote (p < 0.01). According to the value of CFR in the remote region, patients were divided into two groups. GroupI Patients with impaired CFR had higher peak cTnI level at admission than GroupII with preserved CFR (36.40:21.38, P < 0.05). Furthermore, in GroupI patients, left ventricular end diastolic volume was higher compared with that in GroupII patients.
Conclusions Microvascular dysfunction in remote myocardium was common and had great significance in clinical. Higher value of CFR in the remote region was prognostic for lack of remodelling after AMI at follow-up.