Long-term cardiovascular outcomes in patients with angina pectoris presenting with bundle branch block

Abstract

Long-term outcomes of unselected patients with angina pectoris and bundle branch block (BBB) on initial electrocardiogram are not well established. The Olmsted County Chest Pain Study is a community-based cohort of 2,271 consecutive patients presenting to 3 Olmsted County emergency departments with angina from 1985 through 1992. Patients were followed for major adverse cardiovascular events (MACEs) including death, myocardial infarction, stroke, and revascularization at 30 days and over a median follow-up period of 7.3 years and for mortality only through a median of 16.6 years. Cox models were used to estimate associations between BBB and cardiovascular outcomes. Mean age of the cohort on presentation was 63 years, and 58% were men. MACEs at 30 days occurred in 11% with right BBB (RBBB), 8.8% with left BBB (LBBB), and 6.4% in patients without BBB (p = 0.17). Over a median follow-up of 7.3 years, patients with BBB were at higher risk for MACEs (RBBB, hazard ratio [HR] 1.85, 95% confidence interval [CI] 1.44 to 2.38, p <0.001; LBBB, HR 2.04, 95% CI 1.62 to 2.56, p <0.001) compared to those without BBB. Over a median of 16.6 years, the 2 BBB groups had lower survival rates than patients without BBB (RBBB, HR 2.19, 95% CI 1.73 to 2.78, p <0.001; LBBB, HR 3.32, 95% CI 2.67 to 4.13, p ≤0.001), but after adjustment for multiple risk factors an increased risk of mortality for LBBB remained significant. In conclusion, appearance of LBBB or RBBB in patients presenting with angina predicts adverse long-term cardiovascular outcomes compared to patients without BBB.