title: Clinical characteristics and prognosis of 60 patients with midventricular obstructive hypertrophic cardiomyopathy.
abstract: BACKGROUND
  Midventricular obstructive hypertrophic cardiomyopathy (MVOHCM) is a rare form of hypertrophic cardiomyopathy. Knowledge regarding the diagnosis, morbidity and cardiovascular mortality is limited. In this study, we aimed to describe the long-term outcomes of patients with MVOHCM followed in a tertiary referral centre.Methods A retrospective study of 60 patients with MVOHCM diagnosed at FuWai Hospital was performed. Clinical features, mortality and cardiovascular morbidity were analysed.
  
  
  RESULTS
  The 60 patients with MVOHCM represented 2.9% of all the hypertrophic cardiomyopathy cases (n = 2068). At diagnosis, the mean age was 40.2 ± 15.0 years. During 7.1 ± 6.3 years of follow-up after diagnosis, the cardiovascular mortality was 15.0%. The probability of survival at 10 years was 77.0 ± 8.0%. The following two predictors of cardiovascular mortality were identified: severe ventricular septal hypertrophy at least 30  mm (hazard ratio, 3.19; P = 0.031) and unexplained syncope (hazard ratio, 4.59; P = 0.002) at baseline. Thirty patients (50.0%) had one or more morbid events, and the most frequent was nonsustained ventricular tachycardia. Apical aneurysm formation was identified in 20% of patients, and the patients with apical aneurysms were more inclined to experience nonsustained ventricular tachycardia than patients without apical aneurysm (58.3 vs. 16.7%; P = 0.003). Peak pressure gradient at least 70  mm Hg (hazard ratio, 3.00; P = 0.01) at baseline was identified as the only predictor of apical aneurysm.
  
  
  CONCLUSIONS
  In Chinese patients, MVOHCM is associated with an unfavourable prognosis of cardiovascular mortality. One-half of these patients experience major cardiovascular events, and 20% develop an apical aneurysm, which significantly increases arrhythmia events. These data warrant measures to ensure the early recognition of MVOHCM followed by appropriate therapeutic interventions.
authors.affiliation: aKey Laboratory of Clinical Trial Research in Cardiovascular Drugs, Ministry of Health, State Key Laboratory of Cardiovascular Diseases bDepartment of Radiology cDepartment of Pathology and Physiology dDepartment of Echocardiography, FuWai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
authors.forename: Li-Rong
authors.initials: LR
authors.lastname: Yan
authors.forename: Shi-Hua
authors.initials: SH
authors.lastname: Zhao
authors.forename: Hong-Yue
authors.initials: HY
authors.lastname: Wang
authors.forename: Fu-Jian
authors.initials: FJ
authors.lastname: Duan
authors.forename: Zhi-Min
authors.initials: ZM
authors.lastname: Wang
authors.forename: Yin-Jian
authors.initials: YJ
authors.lastname: Yang
authors.forename: Xi-Ying
authors.initials: XY
authors.lastname: Guo
authors.forename: Chi
authors.initials: C
authors.lastname: Cai
authors.forename: Zhi-Min
authors.initials: ZM
authors.lastname: Xu
authors.forename: Yi-Shi
authors.initials: YS
authors.lastname: Li
authors.forename: Chao-Mei
authors.initials: CM
authors.lastname: Fan
mesh_terms: D000328:Adult; D002312:Cardiomyopathy, Hypertrophic / Q000150:complications / Q000175:diagnosis* / Q000628:therapy; D015150:Echocardiography, Doppler / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006322:Heart Aneurysm / Q000175:diagnosis / Q000209:etiology; D006801:Humans; D053208:Kaplan-Meier Estimate; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods; D011379:Prognosis; D012189:Retrospective Studies; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods