Lai, Yongqiang

Background: Myocardial bridging (MB) is commonly treated in patients with hypertrophic cardiomyopathy (HCM). However, whether and how MB should be treated in patients with hypertrophic obstructive cardiomyopathy (HOCM) who underwent septal myectomy remain unclear. Methods: A total of 823 adults with HOCM who underwent septal myectomy at the Fuwai Hospital from 2011 to 2017 were retrospectively studied. Results: Overall, 31 events occurred: 24 patients died and 7 had nonfatal myocardial infarction (MI). The 3-year cumulative event-free survival of all-cause death (97.9% vs 100% vs 100% vs 98.4%, p=0.89) and cardiovascular death (98.3% vs 100% vs 100% vs 98.4%, p=0.63) were similar among the four groups (non-MB, CABG, unroofing, untreated, respectively). The 3-year cumulative event-free survival of nonfatal MI (100% vs 97.5% vs 98.0% vs 89.9%, p<0.001) and combined endpoints (97.9% vs 97.5% vs 98.0% vs 88.4%, p=0.02) were significantly lowest in untreated MB. Cox regression analysis indicated that untreated MB was a significant independent predictor of combined endpoints (hazard ratio [HR]: 4.06, 95% confidence interval [CI]: 1.60–10.32, p<0.001). Moreover, 49 patients underwent coronary artery computed tomography after surgery. The patency rate of the saphenous vein graft (SVG) was significantly higher than that of the left internal mammary artery (LIMA) (13.3% vs 84.2%, p<0.001). No MB was detected in the unroofing group. Conclusions: Surgical MB treatment could be beneficial and performed safely during septal myectomy. Myocardial unroofing is the recommended treatment for MB, and unroofing when technically possible may be preferable for long-term outcomes.

AbstractBackgroundObstructive sleep apnea (OSA) is a common disease associated with worse structural and functional impairment of the heart in patients with hypertrophic obstructive cardiomyopathy (HOCM).HypothesisThe presence and severity of OSA can decrease the right ventricular ejection fraction (RVEF) in patients with HOCM.MethodsIn total, 151 consecutive patients with a confirmed diagnosis of HOCM at Fuwai Hospital between September 2017 and September 2018 were included. Polysomnography and cardiac magnetic resonance imaging were performed in all patients.ResultsOverall, 84 (55.6%) patients were diagnosed with OSA. The RVEF significantly decreased with the severity of OSA (none, mild, moderate‐severe: 46.1 ± 8.2 vs 42.9 ± 7.5 vs 41.4 ± 7.4, P = .009). The apnea‐hypopnea index (AHI) was significantly high in patients with RVEF<40% among the different OSA groups (mild, moderate:7.7 ± 2.4 vs 9.6 ± 2.9, P = .03; 24.4 ± 9.0 vs 36.3 ± 18.0, P = .01). In the multiple linear regression model, the right ventricular end‐systolic volume (β = −0.28, P < .001), AHI (β = −0.09, P = .02), and oxygen desaturation index (β = −0.11, P = .04) were independently associated with a decrease in RVEF (adjusted R2 = 0.347, P < .001). Furthermore, the prevalence of RVEF<40% was high in patients with OSA. Compared with RVEF>40%, RVEF<40% was associated with more symptoms, mainly chest pain, chest distress, NYHA class III or IV, pulmonary hypertension, and moderate or severe mitral regurgitation.ConclusionIn patients with HOCM, the presence and severity of OSA is independently associated with a lower RVEF. In addition, compared with patients with RVEF>40%, those with RVEF<40% had more symptoms, including chest pain, chest distress, and NYHA class III or IV.