BACKGROUND An improved understanding of the natural history in NYHA functional class I patients with obstructive hypertrophic cardiomyopathy (oHCM) is needed. OBJECTIVES Using a multicenter registry (SHaRe [Sarcomeric Human Cardiomyopathy Registry]), this study described the natural history in patients with oHCM who were classified as NYHA functional class I at the initial visit compared with patients classified as NYHA functional class II and reported baseline characteristics associated with incident clinical events. METHODS Incident events assessed included a composite of NYHA functional class III to IV symptoms, left ventricular ejection fraction <50%, atrial fibrillation, stroke, ventricular arrhythmias, septal reduction therapy, ventricular assist device or transplantation, or death. Factors associated with incident events were determined using Kaplan-Meier, Cox proportional hazards, and restricted cubic spline models. RESULTS Of 7,964 patients with HCM in SHaRe, 1,239 patients with oHCM met inclusion criteria; 598 were in NYHA functional class I at the initial visit (age 48 ± 17 years; 31.1% female; peak gradient, 75 ± 40 mm Hg). At 5-year follow-up, the composite event rate of NYHA functional class I patients was 28% compared with 44% (P < 0.001) in 641 NYHA functional class II patients with oHCM (age 54 ± 16 years; 46.5% female; peak gradient, 83 ± 39 mm Hg). Left atrial (LA) diameter ≥45 mm (HR: 1.56 [95% CI: 1.14-2.12]; P = 0.005), female sex (HR: 1.61 [95% CI: 1.16-2.24]; P = 0.003), and older age (HR: 1.21 per 10 years [95% CI: 1.09-1.34]; P < 0.001), but not the magnitude of left ventricular outflow tract obstruction, were associated with a higher risk of the composite outcome in NYHA functional class I patients. CONCLUSIONS Although NYHA functional class I patients with oHCM fared better than NYHA functional class II patients, more than one-fourth experienced adverse events over 5-year follow-up, especially if they were older, female, and/or had LA enlargement. Strategies to reduce the rate of clinical outcomes in NYHA functional class I patients warrant further study.

中文翻译：

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NYHA 功能 I 级阻塞性肥厚型心肌病患者的临床轨迹。


背景 需要更好地了解 NYHA 功能等级 I 级阻塞性肥厚型心肌病 （oHCM） 患者的自然病程。目的 使用多中心登记处 （SHaRe [Sarcomeric Human Cardiomyopathy Registry]），本研究描述了初次就诊时被归类为 NYHA 功能分级 I 的 oHCM 患者的自然病程，与被归类为 NYHA 功能分级 II 的患者相比，并报告了与事件相关的基线特征。方法 评估的事件包括 NYHA 功能分级 III 至 IV 级症状、左心室射血分数 <50%、心房颤动、中风、室性心律失常、间隔复位治疗、心室辅助装置或移植或死亡的复合。使用 Kaplan-Meier、Cox 比例风险和受限三次样条模型确定与事件事件相关的因素。结果 在 SHaRe 的 7,964 例 HCM 患者中，1,239 例 oHCM 患者符合纳入标准;598 例在初次就诊时处于 NYHA 功能分级 I 级（年龄 48 ± 17 岁;31.1% 为女性;峰梯度为 75 ± 40 毫米汞柱）。在 5 年随访中，NYHA 功能分级 I 患者的复合事件发生率为 28%，而 641 例 NYHA 功能分级 II 级 oHCM 患者 （年龄 54 ± 16 岁;46.5% 女性;峰值梯度，83 ± 39 mm Hg）的复合事件发生率为 44% （P < 0.001）。左心房 （LA） 直径 ≥45 毫米 （HR： 1.56 [95% CI： 1.14-2.12];P = 0.005）、女性 （HR： 1.61 [95% CI： 1.16-2.24];P = 0.003）和高龄 （HR： 1.21/10 年 [95% CI： 1.09-1.34];P < 0.001），但与左心室流出道梗阻的程度无关，与 NYHA 功能分级 I 患者复合结局的较高风险相关。 结论 尽管 NYHA 功能 I 级 oHCM 患者预后优于 NYHA 功能 II 级患者，但超过 1/4 的患者在 5 年随访中经历了不良事件，特别是如果他们年龄较大、女性和/或有 LA 扩大。降低 NYHA 功能 I 类患者临床结局发生率的策略值得进一步研究。