We examined the relations between right bundle branch block (RBBB) and clinical characteristics, management, and outcomes among a broad spectrum of patients with acute coronary syndrome (ACS). Admission electrocardiograms of patients enrolled in the Global Registry of Acute Coronary Events (GRACE) electrocardiogram substudy and the Canadian ACS Registry I were analyzed independently at a blinded core laboratory. We performed multivariable logistic regression analysis to assess the independent prognostic significance of admission RBBB on in-hospital and 6-month mortality. Of 11,830 eligible patients with ACS (mean age 65; 66% non-ST-elevation ACS), 5% had RBBB. RBBB on admission was associated with older age, male sex, more cardiovascular risk factors, worse Killip class, and higher GRACE risk score (all p < 0.01). Patients with RBBB less frequently received in-hospital cardiac catheterization, coronary revascularization, or reperfusion therapy (all p < 0.05). The RBBB group had higher unadjusted in-hospital (8.8% vs 3.8%, p < 0.001) and 6-month mortality rates (15.1% vs 7.6%, p < 0.001). After adjusting for established prognostic factors in the GRACE risk score, RBBB was a significant independent predictor of in-hospital death (odds ratio 1.45, 95% CI 1.02 to 2.07, p = 0.039), but not cumulative 6-month mortality (odds ratio 1.29, 95% CI 0.95 to 1.74, p = 0.098). There was no significant interaction between RBBB and the type of ACS for either in-hospital or 6-month mortality (both p > 0.50). In conclusion, across a spectrum of ACS, RBBB was associated with preexisting cardiovascular disease, high-risk clinical features, fewer cardiac interventions, and worse unadjusted outcomes. After adjusting for components of the GRACE risk score, RBBB was a significant independent predictor of early mortality.

BACKGROUND: While prior work has suggested that a high-grade atrioventricular block (HAVB) in the setting of an acute coronary syndrome (ACS) is associated with in-hospital death, limited information is available on the incidence of, and death associated with, HAVB in ACS patients receiving contemporary management. METHODS AND RESULTS: The incidence of HAVB was determined within The Global Registry of Acute Coronary Events (GRACE). The clinical characteristics, in-hospital therapies, and outcomes were compared between patients with and without HAVB. Factors associated with death in patients with HAVB were determined. A total of 59 229 patients with ACS between 1999 and 2007 were identified; 2.9% of patients had HAVB at any point during the index hospitalization; 22.7% of whom died in hospital [adjusted odds ratio (OR) = 4.2, 95% confidence interval (CI), 3.6-4.9, P < 0.001]. The association between HAVB and in-hospital death varied with type of ACS [OR: ST-segment elevation myocardial infarction (STEMI) = 3.0; non-STEMI = 6.4; unstable angina = 8.2, P for interaction < 0.001]. High-grade atrioventricular block present at the time of presentation to hospital (vs. occurring in-hospital) and early (12 h or no intervention) were associated with improved in-hospital survival, whereas temporary pacemaker insertion was not. Patients with HAVB surviving to discharge had similar adjusted survival at 6 months compared with those without HAVB. A reduction in the rate of, but not in-hospital mortality associated with, HAVB was noted over the study period. CONCLUSION: Although the incidence of HAVB is low and decreasing, this complication continues to have a high risk of in-hospital death.

BACKGROUND: The prognostic impact of atrial fibrillation (AF) in the setting of acute coronary syndrome (ACS) is controversial. Furthermore, there are limited real-world data on the management of ACS patients with history of AF. METHODS: The Global Registry of Acute Coronary Events (GRACE/GRACE2) and Canadian Registry of Acute Coronary Events (CANRACE) enrolled 14,285 patients across Canada between 1999 and 2008. Patients were stratified by the presence of history of AF. We compared clinical characteristics, medical therapies, cardiac procedures, and clinical outcomes between the 2 groups. RESULTS: Overall, 1333 of the enrolled patients (9.3%) had history of AF, of whom 51.5% presented with non-ST-segment elevation myocardial infarction, 29.5% with unstable angina, and 19.1% with ST-segment elevation myocardial infarction. Compared with the group without, patients with a history of AF less frequently received evidence-based antiplatelet and antithrombin therapies, left ventricle ejection fraction assessment, and coronary angiography (all P < 0.001); they also had higher unadjusted rates of in-hospital death, myocardial (re)infarction, and heart failure. However, in multivariable analysis, history of AF was not found to be independently associated with in-hospital mortality (adjusted odds ratio [OR] = 1.12; 95% confidence interval (CI), 0.73-1.73; P = 0.61) or death and/or myocardial reinfarction (adjusted OR = 1.15; 95% CI, 0.87-1.5; P = 0.34). CONCLUSIONS: History of AF is common among ACS patients. They received less evidence-based medical and invasive therapies than ACS patients without history of AF. History of AF is a negative independent predictor of in-hospital coronary angiography but was not found to be independently associated with adverse outcomes. All rights reserved.

Angiotensin-converting enzyme (ACE) inhibitor use in patients at high risk of coronary artery disease has been associated with a decrease in the risk of myocardial infarction (MI) and death. However, it is unclear whether chronic use of these agents modifies the course and outcome of an acute coronary syndrome (ACS). This study assessed the association between chronic use of ACE inhibitors and clinical outcomes in patients with ACS. From 1999 through 2008, 13,632 Canadian patients with ACS were identified in the Global Registry of Acute Coronary Events (GRACE), the expanded GRACE (GRACE(2)), and the Canadian Registry of Acute Coronary Events (CANRACE). Patients were stratified by previous use of an ACE inhibitor. Clinical characteristics, in-hospital treatment, and outcomes were compared between the 2 groups. Multivariable logistic regression analysis adjusting for GRACE risk score and other clinical factors was performed. Patients receiving an ACE inhibitor before the ACS had a higher prevalence of diabetes (40.6% vs 21.2%, p <0.001), previous MI (51.8% vs 23.3%, p <0.001), heart failure (18.0% vs 6.9%), and higher GRACE scores at presentation (133 vs 124, p <0.001). Multivariable analysis demonstrated no significant association between previous ACE inhibitor use and death (adjusted odds ratio [OR] 1.15, confidence interval [CI] 0.90 to 1.49, p = 0.27), in-hospital re-MI (adjusted OR 0.99, CI 0.78 to 1.25, p = 0.91), or the composite end point of death/re-MI (adjusted OR 1.01, CI 0.84 to 1.20, p = 0.94). In conclusion, previous use of an ACE inhibitor is not independently associated with improved in-hospital outcomes after an ACS.