Shingu Yasushige, Ooka Tomonori, Katoh Hiroki, Tachibana Tsuyoshi, Kubota Suguru, Matsui Yoshiro
Department of Cardiovascular and Thoracic Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
Department of Cardiovascular and Thoracic Surgery, Hokkaido University Hospital, Sapporo, Japan.
J Cardiol. 2018 Apr;71(4):329-335. doi: 10.1016/j.jjcc.2017.09.013. Epub 2017 Nov 7.
Although non-transplant surgical interventions for non-ischemic dilated cardiomyopathy (NIDCM) are relatively effective, their feasibility and limitations have not been fully elucidated. The aim of this study was to define the feasibility and limitations of mitral valve repair, with or without surgical ventricular reconstruction for patients with NIDCM in terms of postoperative low cardiac output syndrome (LOS).
Twenty non-transplant candidates (aged 57±13 years) with NIDCM and significant mitral regurgitation had undergone mitral valve repair combined with submitral procedures. Using a 72-mL plastic ellipsoidal sizer, left ventricular reconstruction was performed concomitantly in 14/20 (70%) patients with extremely large ventricles. Total stroke volume, deceleration time of early trans-mitral flow wave, and the slope (Mw) in the preload recruitable stroke-work relationship were assessed using transthoracic echocardiography. LOS was defined as in-hospital death due to heart failure or a cardiac index less than 2.2L/min/m before discharge.
There were three in-hospital deaths and four patients with postoperative cardiac index less than 2.2L/min/m [n=7 (35%), LOS group]. Preoperative total stroke volume, deceleration time, and the Mw were significantly lower in the LOS group compared to those in the non-LOS group; the predicted cut-off values for LOS were 84mL/beat (p=0.008), 133ms (p=0.015), and 45ergcm×10 (p=0.036), respectively. Preoperative left ventricular ejection fraction and ventricular size could not predict postoperative LOS. The one-year survival rate was 0% in the LOS group and 84% in the non-LOS group (p<0.001).
Mitral valve repair, with or without left ventricular reconstruction, could be contraindicated for NIDCM patients with low total stroke volume, deceleration time, and Mw in terms of high postoperative incidence of LOS. For high-risk patients, other therapeutic strategies might be necessary.
尽管非缺血性扩张型心肌病（NIDCM）的非移植手术干预相对有效，但其可行性和局限性尚未完全阐明。本研究的目的是从术后低心排血量综合征（LOS）方面，确定二尖瓣修复术（无论是否联合手术性心室重建）对NIDCM患者的可行性和局限性。
20例患有NIDCM且有严重二尖瓣反流的非移植候选患者（年龄57±13岁）接受了二尖瓣修复术并联合二尖瓣下手术。使用一个72毫升的塑料椭圆形测量器，在14/20（70%）心室极大的患者中同时进行了左心室重建。使用经胸超声心动图评估总心搏量、早期二尖瓣血流波减速时间以及前负荷可募集搏功关系中的斜率（Mw）。LOS定义为因心力衰竭导致的院内死亡或出院前心脏指数低于2.2L/min/m²。
有3例院内死亡，4例患者术后心脏指数低于2.2L/min/m² [n = 7（35%），LOS组]。与非LOS组相比，LOS组术前总心搏量、减速时间和Mw显著更低；LOS的预测临界值分别为84mL/次搏动（p = 0.008）、133ms（p = 0.015）和45erg·cm×10（p = 0.036）。术前左心室射血分数和心室大小无法预测术后LOS。LOS组的一年生存率为0%，非LOS组为84%（p < 0.001）。
就术后LOS发生率高而言，对于总心搏量、减速时间和Mw较低的NIDCM患者，二尖瓣修复术（无论是否联合左心室重建）可能是禁忌的。对于高危患者，可能需要其他治疗策略。
