A NEW study has found that new-onset left bundle-branch block (LBBB) after surgical aortic valve replacement (SAVR) is linked to increased long-term mortality and occurs more frequently in patients with bicuspid aortic valve aortic stenosis (BAV-AS) than in those with tricuspid aortic valve aortic stenosis (TAV-AS).
The study aimed to investigate the incidence and outcomes of postoperative conduction disturbances, including third-degree atrioventricular (AV) block and LBBB, in BAV-AS and TAV-AS patients. By focusing on conduction disturbances, this research sought to enhance clinical understanding of complications that arise after SAVR, with implications for the management and follow-up of patients with different aortic valve morphologies.
A total of 1,147 patients undergoing isolated SAVR, either with or without accompanying ascending aortic surgery, were evaluated from January 2005 to December 2022. Participants were stratified into BAV (n=589) and TAV (n=558) groups, excluding those with pre-existing conduction disturbances. Incidence rates of postoperative third-degree AV block, requiring permanent pacemaker insertion, and new-onset LBBB were determined during initial hospitalization. Long-term survival impacts of new-onset conduction disturbances were tracked over a median follow-up of 8.2 years. Within the BAV group, patients were further categorized by valve morphology based on Sievers and Schmidtke’s classification, allowing analysis of subtype-specific risks. The results showed that 4.5% of patients developed third-degree AV block, and 7.8% developed LBBB. BAV-AS patients had a significantly higher risk of third-degree AV block (6.5% vs. 2.5%, P=0.001) and LBBB (9.7% vs. 5.7%, P=0.013) compared to TAV-AS patients. Moreover, new-onset LBBB was associated with increased all-cause mortality (adjusted hazard ratio 1.60, P=0.011), while third-degree AV block did not impact long-term survival. BAV-AS patients with fused right and non-coronary cusps showed the highest risk of conduction disturbances.
In conclusion, new-onset LBBB after SAVR presents a significant mortality risk and is more common in BAV-AS patients, especially in those with specific cusp fusions. These findings suggest that clinicians should consider valve morphology, particularly in BAV-AS cases, during preoperative planning and postoperative monitoring, as it may guide risk stratification and management strategies to improve patient outcomes.
Reference
Wedin JO et al. Conduction disturbances and outcome after surgical aortic valve replacement in patients with bicuspid and tricuspid aortic stenosis. Circulation. 2024;DOI:10.1161/CIRCULATIONAHA.124.070753.
