Impact of obstructive sleep apnea on new-set atrial fibrillation after septal myectomy in patients with hypertrophic obstructive cardiomyopathy

BACKGROUND: Obstructive sleep apnea (OSA) is associated with a higher prevalence of postoperative atrial fibrillation in patients who underwent cardiac surgery. However, whether OSA is a risk factor for postoperative atrial fibrillation after septal myectomy remains unclear. We hypothesized that OSA was associated with postoperative atrial fibrillation after septal myectomy. METHODS: A total of 99 patients with hypertrophic obstructive cardiomyopathy who underwent septal myectomy were included in our manuscript. Polysomnography was performed in all patients, and the heart rhythm was continuously monitored during the perioperative period. RESULTS: In the present study, 25 (25.3%) patients developed postoperative atrial fibrillation after septal myectomy. The prevalence of postoperative atrial fibrillation was significantly higher in patients with OSA and increased with the worsening severity of OSA. Notably, the apnea-hypoxia index was significantly higher in patients with postoperative atrial fibrillation among the different OSA groups. In receiver operating characteristic analysis, the area under the curve for the apnea-hypopnea index was 0.785 (95% CI: 0.684–0.887, P<0.001); an apnea-hypopnea index of 10.4 was the optimal cutoff point to predict postoperative atrial fibrillation. In the multivariable analysis, apnea-hypopnea index ≥10.4 (odds ratio: 6.29, 95% CI: 2.18–18.14, P=0.001), moderate-to-severe OSA (odds ratio: 4.88, 95% CI: 1.42–16.86, P=0.01), and left atrium diameter (odds ratio: 1.12, 95% CI: 1.03–1.22, P=0.01) were independent risk factors associated with postoperative atrial fibrillation after adjusting for relevant variables. However, the association between the diagnosis of OSA and postoperative atrial fibrillation was no longer statistically significant. CONCLUSIONS: The severity of OSA reflected by the apnea-hypopnea index in patients with obstructive hypertrophic cardiomyopathy who underwent surgery is an independent risk factor for postoperative atrial fibrillation, which is associated with adverse clinical outcomes.