Bicuspid aortic valve stenosis was associated with higher rates of new-onset LBBB after SAVR compared to tricuspid morphology (9.7% vs 5.7%), increasing mortality risk (HR 1.60; 95% CI 1.12-2.30).
Cohort (n=1,147)
Does bicuspid aortic valve morphology increase the risk of new-onset conduction disturbances after surgical aortic valve replacement in patients with aortic stenosis compared to tricuspid aortic valve morphology?
Patients with bicuspid aortic valve stenosis, particularly those with fusion of the right- and non-coronary cusps, have a significantly higher risk of developing new-onset LBBB and third-degree AV block after surgical aortic valve replacement, with new-onset LBBB being associated with increased long-term mortality.
Absolute Event Rate: 6.5% vs 2.5%
p-value: p=0.001
BACKGROUND: This study aimed to compare the incidence and prognostic implications of new-onset conduction disturbances after surgical aortic valve replacement (SAVR) in patients with bicuspid aortic valve (BAV) aortic stenosis (AS) versus patients with tricuspid aortic valve (TAV) AS (ie, BAV-AS and TAV-AS, respectively). Additionally, the study included stratification of BAV patients according to subtype. METHODS: In this cohort study, the incidence of postoperative third-degree atrioventricular (AV) block with subsequent permanent pacemaker requirement and new-onset left bundle-branch block (LBBB) was investigated in 1147 consecutive patients without preoperative conduction disorder who underwent isolated SAVR (with or without ascending aortic surgery) between January 1, 2005, and December 31, 2022. The groups were stratified by aortic valve morphology (BAV, n=589; TAV, n=558). The outcomes of interests were new-onset third-degree AV block or new-onset LBBB during the index hospitalization. The impact of new-onset postoperative conduction disturbances on survival was investigated in BAV-AS and TAV-AS patients during a median follow-up of 8.2 years. BAV morphology was further categorized according to the Sievers and Schmidtke classification system (possible in 307 BAV-AS patients) to explore association between BAV subtypes and new-onset conduction disturbances after SAVR. RESULTS: The overall incidence of third-degree AV block and new-onset LBBB after SAVR was 4.5% and 7.8%, respectively. BAV-AS patients had a higher incidence of both new-onset third-degree AV block (6.5% versus 2.5%; P =0.001) and new-onset LBBB (9.7% versus 5.7%; P =0.013) compared with TAV-AS patients. New-onset LBBB was associated with an increased all-cause mortality during follow-up (adjusted hazard ratio, 1.60 95% CI, 1.12–2.30; P =0.011), whereas new-onset third-degree AV block was not associated with worse prognosis. Subgroup analysis of the BAV cohort revealed that BAV-AS patients with fusion of the right- and non-coronary cusps had the highest risk of new-onset third-degree AV block (adjusted odds ratio aOR, 8.33 95% CI, 3.31–20.97; P <0.001, with TAV as reference group) and new-onset LBBB (aOR, 4.03 95% CI, 1.84–8.82; P <0.001, with TAV as reference group), whereas no significant association was observed for the other BAV subtypes. CONCLUSIONS: New-onset LBBB after SAVR is associated with increased all-cause mortality during follow-up, and is more frequent complication in BAV AS patients compared with TAV-AS patients. BAV-AS patients with fusion of the right- and non-coronary cusps have an increased risk for conduction disturbances after SAVR. This should be taken into consideration when managing these patients.
Wedin et al. (Wed,) conducted a cohort in Bicuspid and Tricuspid Aortic Stenosis (n=1,147). Surgical aortic valve replacement in bicuspid aortic valve stenosis vs. Surgical aortic valve replacement in tricuspid aortic valve stenosis was evaluated on New-onset third-degree AV block during index hospitalization (p=0.001). Bicuspid aortic valve stenosis was associated with higher rates of new-onset LBBB after SAVR compared to tricuspid morphology (9.7% vs 5.7%), increasing mortality risk (HR 1.60; 95% CI 1.12-2.30).