Predictive Effect of Atypical Right Bundle-Branch Block on In-Hospital Sudden Cardiac Death and Cardiac Rupture and Long-Term Prognosis in Patients With Acute Myocardial Infarction Who Underwent Percutaneous Coronary Intervention

Abstract

Background: A study was conducted to explore the predictive effect of atypical right bundle-branch blocks (ARBBB) on in-hospital sudden cardiac death (SCD), cardiac rupture (CR), and long-term prognosis in patients with acute myocardial infarction undergoing percutaneous coronary intervention with a drug-eluting stent.

Methods and results: A total of 13 886 patients with first-episode acute myocardial infarction who underwent percutaneous coronary intervention with a drug-eluting stent at 3 centers from January 2017 to January 2022 were included in this retrospective study. Patients were categorized into 4 groups: ARBBB (n=348), typical right BBB (n=374), left BBB (n=366), and non-BBB (n=12 798). The primary end points were in-hospital SCD and CR, the secondary end points were 2-year major adverse cardiovascular and cerebrovascular events. During the in-hospital observation period, 334 patients (2.4%) experienced SCD, with 98 (0.7%) attributed to CR. The incidences of in-hospital SCD and CR in the group with ARBBB were significantly higher than those in the other 3 groups (ARBBB versus left BBB versus typical right BBB versus non-BBB: SCD, 10.6% versus 5.7% versus 4.3% versus 2.0%, P=0.001; CR, 5.7% versus 2.7% versus 1.3% versus 0.5%, P<0.001). ARBBB was a statistically significant predictor of in-hospital SCD (hazard ratio [HR], 2.45 [95% CI, 1.65-4.78], P<0.001) and CR (HR, 3.32 [95% CI, 1.77-7.74], P<0.001). ARBBB could also predicted the 2-year major adverse cardiovascular and cerebrovascular events (HR, 2.99 [95% CI, 1.65-5.53], P<0.001).

Conclusions: ARBBB is a predictor of in-hospital SCD, CR, and 2-year major adverse cardiovascular and cerebrovascular events in patients with first-episode acute myocardial infarction undergoing percutaneous coronary intervention with a drug-eluting stent.

Keywords: MACCE; acute myocardial infarction; atypical right bundle‐branch block; cardiac rupture; percutaneous coronary intervention; sudden cardiac death.

Figure 1. Flow diagram of participant selection.

AMI indicates acute myocardial infarction; CABG, coronary artery bypass grafting; DES, drug‐eluting stent; MI, myocardial infarction; and PCI, percutaneous coronary intervention.

Figure 2. Performance of different types of bundle‐branch block on electrocardiography.

A, TRBBB; B, LBBB. Performance of ARBBB on ECG: Notches were observed in the ascending segment of the R‐wave in the V1 lead, which can be classified into different types as qR (C, red arrow), QR (D, red arrow), and M (E, red arrow) according to the morphology of the QRS wave in the V1 lead. Additionally, a single R‐wave‐like change was also observed in the V1 lead without prominent Q and S waves, with no notch in either the rising or falling segment (F, red arrow). ARBBB indicates atypical right bundle‐branch block; BBB, bundle‐branch block; LBBB, left bundle‐branch block; NBBB, nonbundle‐branch block; and TRBBB, typical right bundle‐branch block.

Figure 3. ECG and coronary angiogram of a typical AMI case with ARBBB that developed CR after DES‐PCI.

A notch appeared in the ascending segment of the R‐wave in lead V1 on ECG (A, red arrow). Coronary angiography showed the proximal acute occlusion of the LAD (B, red arrow). The LAD lesion was successfully opened via DES‐PCI (C, red arrow). A pigtail catheter was used for left ventriculography, and the X‐ray image indicated contrast agent leakage into the pericardium through the free wall of the left ventricle (D through E, red arrow). AMI indicates acute myocardial infarction; ARBBB, atypical right bundle‐branch block; CR, cardiac rupture; DES‐PCI, percutaneous coronary intervention with drug‐eluting stent; and LAD, left anterior descending coronary artery.

Figure 4. Kaplan–Meier curves for SCD and CR in all patients with first‐episode AMI after DES‐PCI.

The log‐rank comparison test showed significant differences in the cumulative rates of SCD and CR among the 4 groups stratified by BBB type. A, SCD, P<0.001; B, CR, P<0.001. The time of occurrence of SCD in the groups with ARBBB and LBBB was similar and were earlier than in the groups with TRBBB and NBBB (C, P<0.05). The time of occurrence of CR in the group with ARBBB was the earliest, followed by the groups with LBBB, TRBBB, and NBBB (D, P<0.05). *Compared with the group with NBBB, P<0.05; ^&Compared with the group with TRBBB, P<0.05; ^#Compared with the group with LBBB, P<0.05. AMI indicates acute myocardial infarction; ARBBB, atypical right bundle‐branch block; CR, cardiac rupture; DES‐PCI, percutaneous coronary intervention with drug‐eluting stent; LBBB, left bundle‐branch block; NBBB, nonbundle‐branch block; SCD, sudden cardiac death; and TRBBB, typical right bundle‐branch block.