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Impact of pre-existing right or left bundle branch block on patients undergoing surgical aortic valve replacement.

OBJECTIVES
Contemporary data on the prognostic impact of pre-existing left or right bundle branch block on clinical outcomes after aortic valve (AV) replacement are limited. The aim of this study was to evaluate the impact of pre-existing bundle branch block on clinical outcomes in patients undergoing AV replacement.


METHODS
Data from patients who underwent AV replacement surgery between 2004 and 2020 were obtained from our departmental database.


RESULTS
Of the 2704 study patients, 203 (7.5%) had pre-existing bundle branch block and 2501 (92.5%) had normal atrioventricular conduction. The mean age was 68 (13) years, 1697 (63%) were male and 683 (25%) had a unicuspid or bicuspid AV. The in-hospital mortality rate was higher in patients with pre-existing bundle branch block compared to those without on admission (5.9% vs 2.9%, P = 0.032), and more frequent in patients with left compared with right bundle branch block (11.9% vs 4.3%, P = 0.003). New pacemaker implantation was most frequent in those patients with pre-existing left bundle branch block, followed by right and no bundle branch block on admission (28.6% vs 7.5% vs 2.8% respectively, P < 0.001; odds ratio 4.96 95% confidence interval 2.96-8.08, P < 0.001). The 10-year cumulative survival rate was lower in patients with bundle branch block compared with patients with no bundle branch block (76.8% vs 82.8%, log-rank P < 0.001; hazard ratio 0.73, confidence interval 0.54-0.99, P = 0.042).


CONCLUSIONS
This study indicates that patients with pre-existing bundle branch block have a higher incidence of pacemaker implantation and all-cause mortality after AV replacement compared with patients without a conduction disturbance.