Cristea, Ecaterina

Aims: Establishing epicardial flow with percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) is necessary but not sufficient to ensure nutritive myocardial reperfusion. We evaluated whether adding myocardial blush grade (MBG) and quantitative reperfusion ventricular arrhythmia “bursts” (VABs) surrogates provide a more informative biosignature of optimal reperfusion in patients with Thrombolysis in Myocardial Infarction (TIMI) 3 flow and ST-segment recovery (STR). Methods and results: Anterior STEMI patients with final TIMI 3 flow had protocol-blinded analyses of simultaneous MBG, continuous 12-lead electrocardiogram (ECG) STR, Holter VABs, and day 5–14 SPECT imaging infarct size (IS) assessments. Over 20 million cardiac cycles from >4500 h of continuous ECG monitoring in subjects with STR were obtained. IS and clinical outcomes were examined in patients stratified by MBG and VABs. VABs occurred in 51% (79/154) of subjects. Microcirculation (MBG 2/3) was restored in 75% (115/154) of subjects, of whom 53% (61/115) had VABs. No VABs were observed in subjects without microvascular flow (MBG of 0). Of 115 patients with TIMI 3 flow, STR, and MBG 2/3, those with VABs had significantly larger IS (median: 23.0% vs 6.0%, p=0.001). Multivariable analysis identified reperfusion VABs as a factor significantly associated with larger IS ( p=0.015). Conclusions: Despite restoration of normal epicardial flow, open microcirculation, and STR, concomitant VABs are associated with larger myocardial IS, possibly reflecting myocellular injury in reperfusion settings. Combining angiographic and ECG parameters of epicardial, microvascular, and cellular response to STEMI intervention provides a more predictive “biosignature” of optimal reperfusion than do single surrogate markers.

Background— The clinical significance of incomplete coronary revascularization (ICR) after percutaneous coronary intervention in patients with acute coronary syndromes is unknown. Methods and Results— We performed quantitative angiography of the entire coronary tree in 2954 patients with acute coronary syndromes in the Acute Catheterization and Urgent Intervention Triage Strategy (ACUITY) trial. ICR was variably defined if any lesion with diameter stenosis (DS) cutoffs ranging from ≥30% to ≥70% with reference vessel diameter ≥2.0 mm remained after percutaneous coronary intervention. The primary outcome was 1-year composite rate of major adverse cardiac events (death, myocardial infarction, or ischemia-driven unplanned revascularization). With the use of DS cutoffs ≥30%, ≥40%, ≥50%, ≥60%, and ≥70%, the prevalence of ICR after percutaneous coronary intervention was 75%, 55%, 37%, 25%, and 17%, respectively. The 1-year major adverse cardiac event rate was increased among patients with ICR using all of the DS cutoffs. ICR (≥50% DS) was associated with higher 1-year rates of myocardial infarction (12.0% versus 8.2%; hazard ratio, 1.50; 95% confidence interval, 1.18–1.89; P =0.0007) and ischemia-driven unplanned revascularization (15.7% versus 10.2%; hazard ratio, 1.58; 95% confidence interval, 1.28–1.96; P <0.0001), with a trend toward increased mortality (3.1% versus 2.2%; hazard ratio, 1.43; 95% confidence interval, 0.90–2.27; P =0.13). By multivariable analysis, ICR (≥50% DS) was an independent predictor of 1-year major adverse cardiac events (hazard ratio, 1.36; 95% confidence interval, 1.12–1.64; P =0.002). The impact of ICR on major adverse cardiac events was similar regardless of chronic total occlusion presence, but it was more pronounced with a greater number of nonrevascularized lesions. Conclusions— Depending on the threshold of percent DS, ICR was present in 17% to 75% of patients with acute coronary syndromes after percutaneous coronary intervention. Regardless of the threshold, ICR was strongly associated with 1-year myocardial infarction, ischemia-driven unplanned revascularization, and major adverse cardiac events. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00093158.