Journal of Invasive Cardiology

Angiographic analysis. Angiographic images were acquired using a GE INOVA-2000 single-plane system (GE Healthcare, Wauwatosa, Wisconsin) at a cine rate of 30 frames per second. Basal TIMI flow and collateral circulation to the culprit vessel were evaluated on the first angiogram. TIMI flow grades (TFGs), corrected TIMI frame count (CTFC) and TIMI myocardial perfusion grade (TMPG) were graded on the angiograms taken immediately after PCI. Epicardial blood flow was assessed by use of either TFGs18 or CTFC,19,20 and myocardial perfusion by use of TMPG.21 A latero-lateral view for the left anterior descending (LAD) coronary artery, a left anterior oblique 45° view for the right coronary artery (RCA), and a caudal 45° or right anterior oblique 30° view for the circumflex artery were used in most cases. Ten seconds of cine filming were required to allow some filling of the venous system and to evaluate the washout phase of contrast dye. To facilitate the subjective grading of TMPG, angiograms were digitized and a logarithmic nonmagnified mask-mode background subtraction was applied to the image subset to eliminate non-contrast medium densities. The TMPGs were assessed as previously defined by Gibson et al in 2000.21 In brief, in TMPG 0, there is minimal or no myocardial blush; in TMPG 1, dye stains the myocardium and this stain persists on the next injection; in TMPG 2, dye enters the myocardium but washes out slowly so that dye is strongly persistent at the end of the injection; and in TMPG 3, normal entrance and exit of dye are in the myocardium so that dye is mildly persistent at the end of the injection. Every case was analyzed by the two cardiologists who were blinded to the patients’ identity, ECG and echocardiographic outcome, and a third cardiologist provided the final result if there was disparity in the TFGs and TMPGs between the two cardiologists. CTFC for every case was calculated by the mean value of the two cardiologists’ measurements.

Electrocardiography analysis. An 18-lead ECG was recorded just before and at the end of the procedure. Analysis was performed by one observer who was unaware of the clinical and angiographic data. The sum of ST-segment elevation (ΣSTe) was measured manually 20 ms after the end of QRS complex from leads exploring the infarct area. Resolution of ΣSTe after PCI was quantified as a percentage of the value obtained from the basal ECG. A > 50% reduction of the initial value was considered significant ΣSTe recovery.

Echocardiography analysis. A two-dimensional echocardiogram was performed in-hospital and at 1-year follow up for the evaluation of left ventricular (LV) wall motion and LV ejection fraction (LVEF). The analysis was carried out by two observers blinded to the clinical and angiographic data.

Clinical follow up. Clinical follow-up data were obtained from out-patient examinations or by the investigators who made telephone contact with patients at about 1 year post PCI. In-hospital and 1-year complications included death, heart failure, reinfarction and angina requiring revascularization.