In symptomatic obstructive hypertrophic cardiomyopathy (oHCM) patients, mavacamten is commercially approved to help improve left ventricular (LV) outflow tract (LVOT) gradients, symptoms, and reduce eligibility for septal reduction therapy (SRT) under the risk evaluation and mitigation strategy (REMS) program. We sought to prospectively report the initial real-world clinical experience with the use of commercially available mavacamten in a multi-hospital tertiary healthcare system. We studied the first 150 consecutive oHCM patients (mean age 65 years, 53% women, 83% on betablockers and 61% in New York Heart Association [NYHA] class III) who were initiated on 5 mg of mavacamten with dose titrations using symptom assessment and echocardiographic measurements of LVOT gradient and LV ejection fraction (LVEF) measurements. We measured changes in NYHA class, LVEF, LVOT gradients (resting and Valsalva) at baseline, 4, 8 and 12 weeks. At 261 ± 143 days (range of 31–571 days), 69 (46%) patients had ≥1 NYHA class, and 27 (18%) additional patients had ≥2 NYHA class improvement. The mean Valsalva LVOT gradient decreased from 72 ± 43 mmHg at baseline to 29 ± 31 mmHg at 4 weeks, 29 ± 28 mmHg at 8 weeks and 30 ± 29 mmHg at 12 weeks ( < 0.001). At baseline, 100% patients had Valsalva LVOT gradients ≥30 mmHg, which reduced to 29% at 4 weeks, 28% at 8 weeks and 30% at 12 weeks. In 40 patients who reported no symptomatic improvement, the mean Valsalva LVOT gradient decreased from 73 ± 39 mmHg at baseline to 34 ± 27 mmHg at 4 weeks, 35 ± 28 mmHg at 8 weeks and 30 ± 24 mmHg at 12 weeks ( < 0.001). The mean LVEF at baseline was 66 ± 6% and changed to 64 ± 5% at 4 weeks, 63 ± 5% at 8 weeks and 62 ± 7% at 12 weeks ( < 0.0001). No patient underwent SRT, developed LVEF ≤30% or developed heart failure requiring admission. Three (2%) patients needed temporary interruption of mavacamten due to LVEF<50%. In a real-world study in symptomatic oHCM patients at a multi-hospital tertiary care referral center, we demonstrate the efficacy and safety, along with the logistic feasibility of prescribing mavacamten under the REMS program.

中文翻译：

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mavacamten 治疗梗阻性肥厚型心肌病的真实经验：来自三级护理中心的观察

在有症状的梗阻性肥厚型心肌病 (oHCM) 患者中，mavacamten 已获得商业批准，可帮助改善左心室 (LV) 流出道 (LVOT) 梯度、症状，并根据风险评估和缓解策略 (REMS) 降低室间隔复位治疗 (SRT) 的资格） 程序。我们试图前瞻性地报告在多医院三级医疗保健系统中使用市售 mavacamten 的初始真实临床经验。我们研究了前 150 名连续的 oHCM 患者（平均年龄 65 岁，53% 为女性，83% 服用β受体阻滞剂，61% 为纽约心脏协会 [NYHA] III 级），这些患者开始服用 5 mg mavacamten，并根据症状评估进行剂量滴定以及 LVOT 梯度和 LV 射血分数 (LVEF) 测量的超声心动图测量。我们测量了基线、第 4、8 和 12 周时 NYHA 分级、LVEF、LVOT 梯度（静息和 Valsalva）的变化。在 261 ± 143 天（范围为 31-571 天）时，69 名 (46%) 患者具有 ≥1 NYHA 等级，另外 27 名 (18%) 患者具有 ≥2 NYHA 等级改善。平均 Valsalva LVOT 梯度从基线时的 72 ± 43 mmHg 降至 4 周时的 29 ± 31 mmHg、8 周时的 29 ± 28 mmHg 和 12 周时的 30 ± 29 mmHg (< 0.001)。基线时，100% 的患者 Valsalva LVOT 梯度≥30 mmHg，第 4 周时降至 29%，第 8 周时降至 28%，第 12 周时降至 30%。在 40 名症状无改善的患者中，平均 Valsalva LVOT 梯度从基线时的 73 ± 39 mmHg 降至 4 周时的 34 ± 27 mmHg、8 周时的 35 ± 28 mmHg 和 12 周时的 30 ± 24 mmHg (< 0.001) 。基线时的平均 LVEF 为 66 ± 6%，第 4 周时变为 64 ± 5%，第 8 周时变为 63 ± 5%，第 12 周时变为 62 ± 7% (< 0.0001)。没有患者接受 SRT、出现 LVEF ≤ 30% 或出现需要入院的心力衰竭。三名 (2%) 患者因 LVEF<50% 需要暂时中断 mavacamten。在多医院三级护理转诊中心对有症状的 oHCM 患者进行的一项真实世界研究中，我们证明了根据 REMS 计划开出 mavacamten 的有效性和安全性以及后勤可行性。