Hypertrophic Cardiomyopathy Center, Division of Cardiology, Tufts Medical Center, Boston, Massachusetts.
Hypertrophic Cardiomyopathy Center, Division of Cardiology, Tufts Medical Center, Boston, Massachusetts.
J Am Coll Cardiol. 2016 Mar 29;67(12):1399-1409. doi: 10.1016/j.jacc.2016.01.023.
Left ventricular outflow tract gradients are absent in an important proportion of patients with hypertrophic cardiomyopathy (HCM). However, the natural course of this important patient subgroup remains largely unresolved.
The authors systematically employed exercise (stress) echocardiography to define those patients without obstruction to left ventricular outflow at rest and/or under physiological exercise and to examine their natural history and clinical course to create a more robust understanding of this complex disease.
We prospectively studied 573 consecutive HCM patients in 3 centers (44 ± 17 years; 66% male) with New York Heart Association functional class I/II symptoms at study entry, including 249 in whom left ventricular outflow tract obstruction was absent both at rest and following physiological exercise (<30 mm Hg; nonobstructive HCM) and retrospectively assembled clinical follow-up data.
Over a median follow-up of 6.5 years, 225 of 249 nonobstructive patients (90%) remained in classes I/II, whereas 24 (10%) developed progressive heart failure to New York Heart Association functional classes III/IV. Nonobstructive HCM patients were less likely to experience advanced limiting class III/IV symptoms than the 324 patients with outflow obstruction (1.6%/year vs. 7.4%/year rest obstruction vs. 3.2%/year provocable obstruction; p < 0.001). However, 7 nonobstructive patients (2.8%) did require heart transplantation for progression to end stage versus none of the obstructive patients. HCM-related mortality among nonobstructive patients was low (n = 8; 0.5%/year), with 5- and 10-year survival rates of 99% and 97%, respectively, which is not different from expected all-cause mortality in an age- and sex-matched U.S. population (p = 0.15).
HCM patients with nonobstructive disease appear to experience a relatively benign clinical course, associated with a low risk for advanced heart failure symptoms, other disease complications, and HCM-related mortality, and largely without the requirement for major treatment interventions. A small minority of nonobstructive HCM patients progress to heart transplant.
在很大一部分肥厚型心肌病（HCM）患者中，左心室流出道梯度并不存在。然而，这一重要亚组患者的自然病程在很大程度上仍未得到解决。
作者系统地采用运动（压力）超声心动图来确定那些在静息和/或生理运动时左心室流出道无梗阻的患者，并检查他们的自然病史和临床病程，以更深入地了解这种复杂的疾病。
我们前瞻性地研究了 3 个中心的 573 例连续 HCM 患者（44 ± 17 岁；66%为男性），这些患者在研究开始时具有纽约心脏协会功能 I/II 级症状，其中 249 例在静息和生理运动后（<30mmHg；非梗阻性 HCM）均无左心室流出道梗阻，我们回顾性地收集了临床随访数据。
在中位数为 6.5 年的随访中，249 例非梗阻性患者中有 225 例（90%）仍处于 I/II 级，而 24 例（10%）发展为纽约心脏协会功能 III/IV 级的进行性心力衰竭。非梗阻性 HCM 患者发生晚期限制 III/IV 级症状的可能性低于有流出道梗阻的 324 例患者（1.6%/年 vs. 静息梗阻 7.4%/年 vs. 可诱导梗阻 3.2%/年；p < 0.001）。然而，7 例（2.8%）非梗阻性患者因进展为终末期心力衰竭而需要进行心脏移植，而梗阻性患者中无一例需要移植。非梗阻性患者的 HCM 相关死亡率较低（n = 8；0.5%/年），5 年和 10 年的生存率分别为 99%和 97%，与年龄和性别匹配的美国人群的全因死亡率无差异（p = 0.15）。
非梗阻性疾病的 HCM 患者似乎经历了相对良性的临床病程，发生晚期心力衰竭症状、其他疾病并发症和 HCM 相关死亡率的风险较低，且无需进行主要治疗干预。少数非梗阻性 HCM 患者进展为心脏移植。
