Gelfand Eli V, Haffajee Jessica A, Hauser Thomas H, Yeon Susan B, Goepfert Lois, Kissinger Kraig V, Delatorre Ralph, Manning Warren J
Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
J Heart Valve Dis. 2010 Jan;19(1):43-50.
For patients with chronic severe mitral regurgitation (MR), one consideration for the timing of mitral valve surgery is the desire to have a preserved postoperative left ventricular ejection fraction (LVEF). It was hypothesized that the preoperative left ventricular (LV) volume and effective forward LVEF (defined as the ratio of forward aortic stroke volume and LV end-diastolic volume (LVEDV)) would accurately predict the intermediate (three-month) LVEF following surgery. It was also hypothesized that at years after successful surgical correction, there would be ongoing positive ventricular remodeling with improvements in systolic function. A quantitative volumetric cardiovascular magnetic resonance (CMR) system was used prospectively to study these relationships, and to define predictors of postoperative LV systolic function after surgery for chronic severe MR.
Twenty patients (eight females, 12 males; mean age 52 +/-12 years) with chronic severe MR, who had been referred for elective mitral valve repair or replacement with chordal preservation, were prospectively enrolled. All patients underwent quantitative CMR with assessment of LV volume, LVEF, and effective forward LVEF prior to, and at three months after, surgery. Fourteen of the patients returned at a median of 27 months after valve surgery for repeat CMR.
The preoperative LVEF was normal in 90% of patients (0.62 +/- 0.09), but the effective forward LVEF was depressed in all subjects (0.36 +/- 0.09). Compared to preoperative values, at three months after surgery the LVEF had declined by 0.16 +/- 0.08 (p < 0.001), whereas the effective forward LVEF was increased by 0.09 +/- 0.10 (p < 0.001) and the LV end-diastolic volume index (LVEDVI) had declined by 32% (p < 0.001). Multivariate analysis demonstrated a significant correlation between postoperative LVEF and both preoperative LV end-systolic volume index (LVESVI) (p = 0.003) and the preoperative effective forward LVEF (p = 0.05). A depressed postoperative LVEF (< 0.50) during the early period was best predicted by a preoperative effective forward LVEF < 0.40 (sensitivity 100%, specificity 75%). At the 27-month follow up, 12 of the 14 patients (86%) had a normal LVEF, and there was a continuing normalization of other LV parameters, including the LVEDVI and LV mass index.
Among patients with chronic severe MR, the preoperative LVESVI best correlated with the three-month postoperative LVEF. A preoperative effective forward LVEF < 0.40 accurately predicted a depressed postoperative LVEE. Over the succeeding two years, there will be ongoing positive LV remodeling. If confirmed in a larger series, the effective forward LVEF may serve as a useful clinical guide for the timing of corrective surgery in this population.
对于慢性重度二尖瓣反流（MR）患者，二尖瓣手术时机的一个考量因素是期望术后左心室射血分数（LVEF）得以保留。研究假设术前左心室（LV）容积和有效前向LVEF（定义为主动脉前向搏出量与左心室舒张末期容积（LVEDV）之比）能够准确预测术后三个月的LVEF。还假设在成功进行手术矫正数年之后，会持续存在正向心室重构，收缩功能得到改善。使用定量容积心血管磁共振（CMR）系统前瞻性地研究这些关系，并确定慢性重度MR手术后左心室收缩功能的术后预测指标。
前瞻性纳入20例慢性重度MR患者（8例女性，12例男性；平均年龄52±12岁），这些患者因择期二尖瓣修复或保留腱索的置换术前来就诊。所有患者在手术前和术后三个月均接受了定量CMR检查，评估左心室容积、LVEF和有效前向LVEF。其中14例患者在瓣膜手术后中位27个月返回进行重复CMR检查。
90%的患者术前LVEF正常（0.62±0.09），但所有受试者的有效前向LVEF均降低（0.36±0.09）。与术前值相比，术后三个月LVEF下降了0.16±0.08（p<0.001），而有效前向LVEF增加了0.09±0.10（p<0.001），左心室舒张末期容积指数（LVEDVI）下降了32%（p<0.001）。多因素分析显示，术后LVEF与术前左心室收缩末期容积指数（LVESVI）（p = 0.003）和术前有效前向LVEF（p = 0.05）均显著相关。术前有效前向LVEF<0.40最能预测术后早期LVEF降低（<0.50）（敏感性100%，特异性75%）。在27个月的随访中，14例患者中有12例（86%）LVEF正常，包括LVEDVI和左心室质量指数在内的其他左心室参数也持续正常化。
在慢性重度MR患者中，术前LVESVI与术后三个月的LVEF相关性最佳。术前有效前向LVEF<0.40可准确预测术后LVEF降低。在随后的两年中，会持续存在正向左心室重构。如果在更大规模的系列研究中得到证实，有效前向LVEF可能成为该人群矫正手术时机的有用临床指导。
