Complementary prognostic utility of myocardial blush grade and ST-segment resolution after primary percutaneous coronary intervention: Analysis from the HORIZONS-AMI trial Sorin J. Brener, MD, a,b Jose M. Dizon, MD, b,c Roxana Mehran, MD, b,d Alejandra Guerchicoff, PhD, b Alexandra J. Lansky, MD, e Michael Farkouh, MD, d Bruce Brodie, MD, f Giulio Guagliumi, MD, g Bernhard Witzenbichler, MD, h Martin Fahy, MS, b Helen Parise, ScD, b and Gregg W. Stone, MD b,c Brooklyn and New York, NY; New Haven, CT; Greensboro, NC; Bergamo, Italy; and Berlin, Germany Background Both ST-segment resolution (STR) and myocardial blush grade (MBG) have prognostic utility after primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction. We sought to clarify how frequently MBG and STR provide discordant measures of reperfusion success and to determine the independent prognostic significance of each on long-term outcomes. Methods In HORIZONS-AMI, core laboratory measures of both MBG and STR were assessed in 2,367 patients undergoing primary PCI. Four groups were identified based on MBG (grades 2/3 vs 0/1) and STR (≥50% vs b50%). A multivariable model identified predictors of death and major adverse cardiac events at 3 years. Results Myocardial blush grade 2/3 was achieved in 77.7% of patients, and STR ≥50% was achieved in 75.1% of patients. Myocardial blush grade and STR were discordant in 765 patients (30.9%). By multivariable analysis, MBG 2/3 compared with 0/1 was an independent predictor of lower mortality at 3 years (4.4% vs 8.4%, adjusted hazard ratio [HR] = 0.57 [0.39, 0.82], P = .003). In contrast, STR ≥50% compared with b50% was not associated with mortality (5.1% vs 5.9%, adjusted HR = 1.11 [0.68, 1.56], P = .89). However, repeated revascularization at 3 years was less frequent when STR ≥50% (12.4% vs 17.6%, adjusted HR = 0.74 [0.58, 0.95], P = .02). In contrast, MBG 2/3 vs 0/1 was not associated with reduced repeated revascularization (13.6% vs 14.1%, adjusted HR = 1.02 [0.79, 1.33], P = .85). Conclusions In HORIZONS-AMI, MBG and STR after primary PCI were concordant in only 70% of patients and provided complementary prognostic information. Myocardial blush grade predicted long-term survival, whereas STR predicted freedom from repeated revascularization. (Am Heart J 2013;0:1-8.) In patients with ST-segment elevation myocardial infarction (STEMI), rapid reperfusion with primary percutaneous coronary intervention (PCI) provides substantial benefits compared with fibrinolytic therapy or no reperfusion. 1 The success of primary PCI can be assessed angiographically by evaluating Thrombolysis in Myocardial Infarction (TIMI) flow and myocardial blush grade (MBG) 2 in the infarct-related artery, and electro- cardiographically by assessing the extent of ST-segment resolution (STR) after PCI. 3 Myocardial blush grade and STR can be evaluated in central core laboratories and provide objective evidence of reperfusion. In different studies, these indicators of reperfusion have been correlated with survival and freedom from major adverse cardiac events (MACE) during follow-up. Few prior studies have examined the comparative prognostic utility of MBG versus STR in patients under- going primary PCI. This question is particularly relevant in cases in which MBG and STR provide discordant mea- sures of reperfusion success; for example, MBG is favor- able (grade 2 or 3) but STR is not (b50%), or vice versa. From the a New York Methodist Hospital, Brooklyn, NY, b Cardiovascular Research Foundation, New York, NY, c Columbia University Medical Center, New York, NY, d Mount Sinai Hospital, New York, NY, e Yale University, New Haven, CT, f LeBauer Cardiovascular Research Foundation, Greensboro, NC, g Ospedali Riuniti di Bergamo, Bergamo, Italy, and h Charité Campus Benjamin Franklin, Berlin, Germany. NCT00433966. Submitted April 29, 2013; accepted July 26, 2013. Reprint requests: Sorin J. Brener, MD, FACC, Professor of Medicine, Director, Cardiac Catheterization Laboratory, NY Methodist Hospital, 506 6th St, KP-2, Brooklyn, NY 11215. E-mail: sjb9005@nyp.org 0002-8703/$ - see front matter © 2013, Mosby, Inc. All rights reserved. http://dx.doi.org/10.1016/j.ahj.2013.07.025