Faculty Bibliography

BACKGROUND: . Unique identifier: NCT00798122

BACKGROUND: Mortality after ST-elevation myocardial infarction (STEMI) has reduced with reperfusion by primary percutaneous coronary intervention (PCI), which may have impacted on the adverse outcomes of cardiogenic shock (CS) and congestive heart failure (CHF). METHODS AND RESULTS: In the APEX-AMI trial, 5,745 patients with STEMI and planned primary PCI were randomly assigned pexelizumab or matching placebo. Post-randomization CS or CHF was adjudicated by a clinical endpoints committee. Treatment assignment to pexelizumab did not influence either endpoint or mortality rates. Cardiogenic shock developed in 196 patients (3.4%) at a median of 6.0 hours (interquartile range 3.9-28.3) post-randomization, and mortality at 90 days was 54.6%. Congestive heart failure occurred in 254 of patients (4.4%) at a median of 2.6 days (IQR 1.0-16.6), and mortality through 90 days was 10.2%; mortality among those with neither endpoint was 2.1%. Patients with CS or CHF were older, were more often female, and had more hypertension and diabetes, but smoked less compared with non-CS/CHF patients (all P < .05). Independent mortality predictors among those with CS or CHF were hyperlipidemia and a history of angina (interaction P = .011 and .008, respectively); procedural predictors among survivors to PCI were pre-PCI Thrombolysis In Myocardial Infarction (TIMI) flow 0-1 and post-PCI TIMI flow <3 (P = .013 and <.0001, respectively). CONCLUSIONS: Survival after CS remains poor despite aggressive reperfusion. Both CS and CHF remain the major causes of death among STEMI patients undergoing primary PCI. Future studies should examine treatments that aim to reduce mortality in these highest risk patients

BACKGROUND: A pooled analysis in cardiogenic shock due to acute coronary syndromes is desirable to assess the effect of early revascularization (ERV) across all ages and a wide spectrum of disease severity. METHODS: Only two randomized controlled trials (RCT), i.e. SMASH and SHOCK, met the inclusion criteria and were combined for a pooled analysis using individual patient data (n = 348). RESULTS: SMASH patients (n = 54, 16%) had more severe disease than SHOCK patients (n = 294, 84%). After adjustment for age, anoxic brain damage, non-inferior myocardial infarction, prior coronary artery bypass graft surgery, renal failure, systolic blood pressure, and selection for coronary angiography, one-year mortality was similar (relative risk SHOCK versus SMASH 0.87, 95% CI: 0.61-1.25). Relative risk of one-year death for ERV versus initial medical stabilization was 0.82 (95% CI: 0.70-0.96). There was no significant difference in the treatment effect by age (</=75 years relative risk at one year 0.79, 95% CI: 0.63-0.99; > 75 years relative risk at one year 0.93, 95% CI: 0.56-1.53; interaction P = 0.10). CONCLUSIONS: Only two RCT have been published emphasizing the difficulty of enrolling critically ill patients. Despite large differences in shock severity, ERV benefit is similar across all ages and not significantly different for the elderly

BACKGROUND: The Occluded Artery Trial (OAT) was a large, randomized controlled trial published in 2006 that demonstrated no benefit to routine percutaneous coronary intervention (PCI) of persistently totally occluded infarct-related arteries (IRA) identified a minimum of 24 hours (on calendar days 3-28) after myocardial infarction (MI). The purpose of this study was to determine the impact of OAT results and consequent change in guideline recommendations for PCI for treatment of persistently occluded IRAs. METHODS: We identified all patients enrolled in the CathPCI Registry, from 2005 to 2008, undergoing catheterization more than 24 hours after MI with a totally occluded native coronary artery and no major OAT exclusion criteria. We examined trends in monthly rates of PCI for occlusions after OAT publication and after guideline revisions. Because reporting of diagnostic catheterizations was not mandatory, we examined trends among hospitals in the highest quartile for reporting of diagnostic procedures. RESULTS: A total of 28 780 patient visits from 896 hospitals were included. Overall, we found no significant decline in the adjusted monthly rate of PCI of occlusions after publication of OAT (odds ratio [OR], 0.997; 95% confidence interval [CI], 0.989-1.006) or after guideline revisions (OR, 1.007; 95% CI, 0.992-1.022). Among hospitals consistently reporting diagnostic catheterizations, there was no significant decline after OAT publication (OR, 1.018; 95% CI, 0.995-1.042), and there was a trend toward decline after guideline revisions (OR, 0.963; 95% CI, 0.920-1.000). CONCLUSION: These findings suggest that the results of OAT and consequent guideline revisions have not, to date, been fully incorporated into clinical practice in a large cross-section of hospitals in the United States

BACKGROUND: In the Superior Yield of the New Strategy of Enoxaparin, Revascularization, and Glycoprotein IIb/IIIa Inhibitors (SYNERGY) study, patients assigned enoxaparin or unfractionated heparin (UFH) were treated with alternative anticoagulant therapy after randomization at physician discretion, a practice made possible because the trial was open label. Using SYNERGY as an example, we demonstrate the difficulty of evaluating the effect of postrandomization events in clinical trials and discuss possible methodology. METHODS AND RESULTS: Patients with and without postrandomization crossovers were characterized and event rates analyzed. Statistical modeling was performed using inverse probability weighting and landmark analyses to evaluate the potential impact of postrandomization crossovers on event rates and treatment effect. Of 9978 SYNERGY patients, 9613 (96.3%) received at least 1 dose of randomized therapy and are included in these analyses. Of these, 740 (7.7%; 554 enoxaparin; 186 UFH) had postrandomization crossover. Crossover patients had higher unadjusted rates of 30-day death/myocardial infarction (MI) (18.9% versus 14.0%), thrombolysis in MI (TIMI) bleeding (16.9% versus 7.6%), Global Use of Strategies to Open Occluded Coronary Arteries bleeding (4.5% versus 2.3%), and transfusions (32.3% versus 15.2%). Adjustment for timing of crossover relative to the events attenuated the difference noted in death/MI but accentuated the association with TIMI bleeding. After adjustment using the inverse probability weighting technique, only a modest difference in the absolute treatment effect was observed between enoxaparin and UFH on death/MI (0.6% [unadjusted] versus 0.8% [adjusted]) and TIMI major bleeding (1.5% [unadjusted] versus 1.0% [adjusted]). The landmark analysis indicated a significant association between crossover from enoxaparin to UFH and TIMI bleeding but not in the other direction, and no crossover association was found in death/MI. CONCLUSIONS: Postrandomization events in clinical trials are accompanied by substantial confounders that require careful consideration. In SYNERGY, postrandomization crossovers occurred in nearly 10% of patients, abetted by the open-label trial design. These patients had increased incidence of bleeding and death/MI, but after adjustment using several modeling techniques, only a modest impact of postrandomization crossovers on treatment effect was observed. The usual methods of analyzing end points cannot adequately address biases in changing treatment in these patients. The potential biases of membership in a postrandomization subgroup, as well as the methods used to account for the biases, should be considered when weighing the strength of results. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00043784