Evaluation of the Predictive Value of Left Anterior Fascicular Block on Determination of Left Main and/or Proximal Left Anterior Descending Coronary Artery Disease in Patients with Stable Angina: A Propensity Score Matching Analysis

Abstract

Introduction: Successful revascularization of lesions located in the left main and/or proximal left anterior descending (LM and/or pLAD) coronary artery improves survival than medical therapy only. Therefore, accurate identification of high-risk patients with suspected stable angina pectoris is critical for outpatient clinics. Since the septal perforators of the left anterior descending coronary artery are the main source of blood supply of the left anterior fascicle, we hypothesized that the presence of left anterior fascicular block (LAFB) can predict obstructive stenoses of LM and/or pLAD coronary arteries in patients with suspected stable angina pectoris. Methods: We consecutively enrolled 790 patients referred for invasive coronary angiography due to suspected stable angina pectoris. Results: The number of patients with LAFB5 was 68 (8.6%). Furthermore, 218 patients (27.6%) had obstructive coronary artery disease (CAD). The prevalence of obstructive CAD, revascularization with coronary artery bypass graft surgery, and obstructive LM and/or pLAD coronary artery lesions was higher in patients with LAFB. From univariate analysis, the presence of LAFB was significantly associated with predicting obstructive LM and/or pLAD lesions (odds ratio: 3,587; 95% confidence interval: 1,465-5,785; p=0.005). However, this association disappeared after adjustment for other cardiovascular risk factors. Conclusion: In patients with suspected stable angina pectoris, LAFB is not frequently a 'normal variant" and is associated with known cardiovascular risk factors. It acts as a marker rather than a determinant of obstructive LM and/or pLAD coronary artery lesions.