Clinical Characteristics, Management, and Outcomes of Acute Coronary Syndrome in Patients With Right Bundle Branch Block on Presentation
Center for Outcomes Research
Cardiology | Cardiovascular Diseases | Health Services Research
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.
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Citation: Chan WK, Goodman SG, Brieger D, Fox KA, Gale CP, Chew DP, Udell JA, Lopez-Sendon J, Huynh T, Yan RT, Singh SM, Yan AT; ACS I and GRACE Investigators. Clinical Characteristics, Management, and Outcomes of Acute Coronary Syndrome in Patients With Right Bundle Branch Block on Presentation. Am J Cardiol. 2016 Mar 1;117(5):754-9. doi: 10.1016/j.amjcard.2015.12.005. Epub 2015 Dec 12. PubMed PMID: 26762726. Link to article on publisher's site
Chan, William K.; Goodman, Shaun G.; Brieger, David; Fox, Keith A. A.; Gale, Chris P.; Chew, Derek P.; Udell, Jacob A.; Lopez-Sendon, Jose; Huynh, Thao; Yan, Raymond T.; Singh, Sheldon M.; Yan, Andrew T.; and ACS I and GRACE Investigators, "Clinical Characteristics, Management, and Outcomes of Acute Coronary Syndrome in Patients With Right Bundle Branch Block on Presentation" (2016). GRACE Publications. 123.