Abstract 17060: Effect of Septal Myectomy on Obstructive Sleep Apnea Syndrome in Patients With Hypertrophic Obstructive Cardiomyopathy

Introduction: Hypertrophic cardiomyopathy (HCM) has a higher prevalence of OSA. The impact of obstructive sleep apnea on perioperative complications in hypertrophic obstructive cardiomyopathy (HOCM) patients undergoing septal myectomy and the impact of septal myectomy on OSA are not yet clear. Therefore, we sought to examine the association between HOCM and OSA before and after septal myectomy. Methods: We studied 69 consecutive patents with a confirmed diagnosis of HOCM who underwent septal myectomy. All patients performed polysomnography before and three months after operation. Results: Of all the patients, 41 (59.4%) were diagnosed with OSA. Compared to patients without OSA, patients with OSA were significantly older. The incidence of atrial fibrillation increased significantly during perioperative period in patients with OSA (31.7% vs 10.7%, p=0.048). Three months after operation, the severity of OSA increased significantly, as reflected by AHI, OAI and HI (11.7[7.2-22.1] vs 25.6(17.7-33.8), p<0.001; 11.6[6.8-17.6] vs 15.1[9.5-20.8], p=0.024;) 4.4[2.5-7.1] vs 8.3[4.1-12.0], p=0.003) while the CAI decreased (0.4[0.0-2.1] vs 0.2[0.0-0.8], p=0.008). In a multivariate linear regression analysis, mean oxygen desaturation and time% with Spo2 <90% during sleep were significantly associated with an increased AHI independently of sex, BMI and gender (p=0.026 and p=0.007, adjusted R 2 =0.365). Conclusions: The severity of OSA increased significantly three months after septal myectomy as reflected by AHI, OAI and HI. The mean oxygen saturation and time% with Spo2 <90% during sleep are independently associated with the increase of AHI.