Decreased no-reflow in patients with anterior myocardial infarction and pre-infarction angina

Aims Pre-infarction angina is associated with better outcome after myocardial infarction. The aim of this study was to assess whether pre-infarction angina is associated with decreased no-reflow after coronary recanalization. Methods and Results Twenty-three patients underwent intracoronary myocardial contrast echocardiography during the acute phase of anterior myocardial infarction after successful recanalization, and before hospital discharge. Myocardial perfusion was graded semi-quantitatively in the area at risk (dyssynergic segments). Global left ventricular function was assessed by radionuclide angiography on days 8 and 42 and regional wall motion was assessed by 2D echocardiography on days 0 and 42. Fourteen patients had pre-infarction angina (angina less than 7 days before myocardial infarction) and nine did not. Baseline characteristics were similar in the two groups. The myocardial contrast echocardiography perfusion score in the area at risk after recanalization was higher in the patients with pre-infarction angina than in those without (0·72±0·19 vs 0·53±0·22, P=0·04), and the incidence of no-reflow (myocardial contrast echocardiography perfusion score ≤0·5) was lower (14% vs 56%,P =0·04). This difference persisted 8±2 days after myocardial infarction (0·87±0·11 vs 0·69±0·26, P=0·04), and was associated with greater mid-term (day 42) improvement in left ventricular function in patients with pre-infarction angina than in those without, as assessed by changes in radionuclide left ventricular ejection fraction (+5·8±8·1% vs −3·3±4·6%, respectively;P=0·01) and by changes in regional wall motion score on 2D echocardiography (−0·61±0·39 vs −0·24±0·17, respectively;P=0·04). Conclusion Pre-infarction angina is associated with preservation of the microvasculature, reflected by reduced no-reflow. This may be a mechanism underlying greater recovery of left ventricular function in patients with pre-infarction angina.