Predicting chronic left ventricular dysfunction 90 days after ST-segment elevation myocardial infarction: An Assessment of Pexelizumab in Acute Myocardial Infarction (APEX-AMI) Substudy.

The purpose of this study was to determine predictors of 90-day left ventricular function following acute ST-segment elevation myocardial infarction (STEMI) using variables from clinical presentation, biomarker testing, and cardiovascular magnetic resonance imaging (CMR). Identifying patients with acute STEMI who experience adverse remodeling and develop left ventricular dysfunction 3 months post-MI is a priority for guiding subsequent therapy. The Assessment of Pexelizumab in Acute Myocardial Infarction trial tested pexelizumab treatment in STEMI patients presenting within 6 hours of symptom onset who were to undergo primary percutaneous coronary intervention. We studied 64 patients within this trial according to a prespecified substudy that included paired core laboratory delayed-enhancement CMR at days 3 and 90 as well as plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP; in picograms per milliliter) measured at randomization and 24 hours. A multivariable model predicting day 90 left ventricular ejection fraction (LVEF) was developed from clinical, biomarker, and imaging findings. Patients had a median age of 60 years (52-68), 89% were male, and 60% had anterior STEMI. Time from symptom onset to percutaneous coronary intervention was 3 hours. The median baseline LVEF was 48% (38%-56%) and was 50% (40%-54%) at 90 days: 7 patients (11%) had an LVEF <35% at 90 days. Patients with a lower 90-day LVEF (as a continuous variable) had a higher 24-hour NT-proBNP (P = .02) and a larger baseline infarct size by CMR (median 15% LV [8%-20% LV]) (P < .01). Microvascular obstruction (no reflow) was greater as measured by CMR (median 2.8% [1.4%-6.1%]) in patients with a lower 90-day LVEF (P < .01). Median baseline and 24-hour NT-proBNP levels were 94 pg/mL (54-292 pg/mL) and 1,448 pg/mL (958-2,599 pg/mL), respectively. In a multivariable model with clinical, biomarker, and imaging variables, only 3 variables independently predicted 90-day LVEF: 24-hour NT-proBNP, baseline CMR infarct size, and microvascular obstruction. Three key pathophysiologic variables of the post-STEMI myocardium measuring baseline infarct size and the extent of microvascular obstruction on CMR and wall tension (24-hour NT-proBNP) independently predicted 90-day LVEF. Further studies linking these measures with earlier use of clinical therapies may be warranted.

Ezekowitz JA ，Armstrong PW ，Granger CB ，Theroux P ，Stebbins A ，Kim RJ ，Patel MR ... -  《-》

Comparison of usefulness of N-terminal pro-brain natriuretic peptide as an independent predictor of cardiac function among admission cardiac serum biomarkers in patients with anterior wall versus nonanterior wall ST-segment elevation myocardial infarction

The purpose of the present study was to determine the prognostic value of N-terminal pro-brain natriuretic peptide (NT-pro-BNP), among other serum biomarkers, on cardiac magnetic resonance (CMR) imaging parameters of cardiac function and infarct size in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention. We measured NT-pro-BNP, cardiac troponin T, creatinine kinase-MB fraction, high-sensitivity C-reactive protein, and creatinine on the patients' arrival at the catheterization laboratory in 206 patients with ST-segment elevation myocardial infarction. The NT-pro-BNP levels were divided into quartiles and correlated with left ventricular function and infarct size measured by CMR imaging at 4 to 6 months. Compared to the lower quartiles, patients with nonanterior wall myocardial infarction in the highest quartile of NT-pro-BNP (> or = 260 pg/ml) more often had a greater left ventricular end-systolic volume (68 vs 39 ml/m(2), p <0.001), a lower left ventricular ejection fraction (42% vs 54%, p <0.001), a larger infarct size (9 vs 4 g/m(2), p = 0.002), and a larger number of transmural segments (11% of segments vs 3% of segments, p <0.001). Multivariate analysis revealed that a NT-pro-BNP level of > or = 260 pg/ml was the strongest independent predictor of left ventricular ejection fraction in patients with nonanterior wall myocardial infarction compared to the other serum biomarkers (beta = -5.8; p = 0.019). In conclusion, in patients with nonanterior wall myocardial infarction undergoing primary percutaneous coronary intervention, an admission NT-pro-BNP level of > or = 260 pg/ml was a strong, independent predictor of left ventricular function assessed by CMR imaging at follow-up. Our findings suggest that NT-pro-BNP, a widely available biomarker, might be helpful in the early risk stratification of patients with nonanterior wall myocardial infarction.

Haeck JD ，Verouden NJ ，Kuijt WJ ，Koch KT ，Van Straalen JP ，Fischer J ，Groenink M ，Bilodeau L ，Tijssen JG ，Krucoff MW ，De Winter RJ ... -  《-》

Pexelizumab and infarct size in patients with acute myocardial infarction undergoing primary percutaneous coronary Intervention: a delayed enhancement cardiac magnetic resonance substudy from the APEX-AMI trial.

The purpose of the study was to understand determinants of infarct size in a primary percutaneous intervention (PCI) population treated with pexelizumab compared with placebo. In the multicenter APEX-AMI (Pexelizumab in Conjunction With Angioplasty in Acute Myocardial Infarction) trial, pexelizumab did not reduce 90-day mortality. Cardiac magnetic resonance (CMR) with delayed enhancement was used in a substudy evaluating infarct size and left ventricular ejection fraction (LVEF). Consecutive patients undergoing primary PCI for first myocardial infarction (MI) as part of the APEX-AMI trial were enrolled in this substudy at 5 centers. The CMR was completed on days 3 to 5 (n=99) and day 90 (n=83) following PCI. Central core lab-masked analyses for quantified LVEF, volumes, and infarct size by planimetry were performed. Patients were 60+/-12 years of age, male (n=83 [84%]), had similar time from symptom onset to presentation (median 2.6 h vs. 2.5 h; p=1.0), and similar baseline ST-segment deviation (13.5 mm vs. 14 mm; p=0.59) in both groups. Pexelizumab-treated patients had smaller infarct size (day 3 LV 10.5% vs. 16.2%, p=0.022; day 90 LV 5.9% vs. 12.4%, p=0.015) and higher LVEF (day 3 50.3% vs. 46.2%, p=0.073; day 90 53.9% vs. 49.3%, p=0.036) compared with placebo-treated patients. The median peak creatine kinase in the pexelizumab group was also significantly less than placebo (922 mg/dl vs. 1,973 mg/dl; p=0.03). Notably, the pexelizumab group had lower Thrombolysis In Myocardial Infarction (TIMI) flow grade pre-PCI (46.9% vs. 75.0%; p=0.018), a difference not seen in the overall APEX-AMI study. A multivariate model including baseline features and pexelizumab treatment found anterior MI location and pre-PCI TIMI flow to be significant independent predictors infarct size (p=0.001), whereas pexelizumab was not (p=0.29). No death, heart failure, or shock was noted in either substudy group at 90 days. In a CMR substudy of pexelizumab in MI, baseline TIMI flow grade and anterior location were the only predictors of infarct size, with a reduction of pre-PCI TIMI flow grade 0 by 28%, leading to a 35% reduction in infarct size. (The APEX-AMI Trial; NCT00091637).

Patel MR ，Worthley SG ，Stebbins A ，Dill T ，Rademakers FE ，Valeti US ，Barsness GW ，Van de Werf F ，Hamm CW ，Armstrong PW ，Granger CB ，Kim RJ ... -  《-》

Relative role of NT-pro BNP and cardiac troponin T at 96 hours for estimation of infarct size and left ventricular function after acute myocardial infarction.

Steen H ，Futterer S ，Merten C ，Jünger C ，Katus HA ，Giannitsis E ... -  《JOURNAL OF CARDIOVASCULAR MAGNETIC RESONANCE》

N-terminal pro-B-type natriuretic peptide is associated with adverse short-term clinical outcomes in patients with acute ST-elevation myocardial infarction underwent primary percutaneous coronary intervention.

Kwon TG ，Bae JH ，Jeong MH ，Kim YJ ，Hur SH ，Seong IW ，Cho MC ，Seung KB ，Jang YS ，Park SJ ，Korea Acute Myocardial Infarction Registry Investigators ... -  《-》