Non-invasive coronary flow reserve after successful primary angioplasty for acute anterior myocardial infarction is an independent predictor of left ventricular adverse remodelling

To assess the usefulness of non-invasive coronary flow reserve (CFR) to predict left ventricular adverse remodelling (LVR) after ST-elevation myocardial infarction (STEMI). Sixty-five consecutive patients (mean age 58 +/- 13 years, 24 women) with a first anterior STEMI, underwent prospectively CFR in the distal part of the left anterior descending artery (LAD), using intravenous adenosine infusion (0.14 mg/kg/min, within 2 min), and a standard echocardiography during the same exam, performed within 24 h after successful primary coronary angioplasty, and 6 months later, while the patients were in stable haemodynamic situation. CFR was defined as the peak hyperaemic LAD flow velocity divided by the baseline flow velocity. LV end-systolic volume (ESV) and end-diastolic volume (EDV), and LV ejection fraction (LVEF) were measured using the biplane Simpson's rule. LVR was defined as an absolute increase of ESV >= 15%. Compared with patients without LVR, patients with LVR (n = 18) had higher peak troponin T levels, wall motion score (WMS), a worse initial angiographic TIMI flow grade, and less improved electrocardiographic ST-segment resolution (all P < 0.05), and lower CFR (1.43 +/- 0.2 vs. 1.97 +/- 0.5, P < 0.01). At 6 months, patients with LVR had higher WMS, ESV, EDV, and lower LVEF compared with patients without LVR (all P < 0.01). Furthermore, acute CFR was significantly correlated to the 6-month LVEF and ESV, and to change of LVEF and ESV (all P < 0.01). In the multivariate analysis, acute CFR and initial angiographic TIMI flow grade were the independent predictors of LVR (all P < 0.01). Receiver-operating characteristic curve analysis demonstrated that a cut-off value of 1.7 for CFR yields a sensitivity of 100% and a specificity of 62% to predict LVR at follow-up (P < 0.001, area under the curve 0.82). Non-invasive CFR is an independent predictor of LVR after successful primary angioplasty of anterior STEMI.