左心室功能严重受损合并跨主动脉瓣压差减低的重度主动脉瓣狭窄患者的外科治疗

Surgery in patients of severe aortic stenosis with low transvalvular gradients and severe left ventricular dysfunction

目的探讨左心室功能严重受损合并跨主动脉瓣压差减低的重度主动脉瓣狭窄（As）患者行主动脉瓣置换（AVR）的手术效果及影响中、远期生存的可能危险因素。方法2005年至2011年，35例AS患者接受AVR手术，平均年龄（58±9）岁；NYHA心功能分级3～4级31例，有晕厥史15例、心绞痛史19例、呼吸困难史28例、急性左心衰史16例。术前主动脉瓣口面积（AVA）（0．70±0．09）cm2、左心室射血分数（LVEF）0．276±0．020、左心室舒张末期内径（LVEDD）（6．3±0．4）cm、主动脉跨瓣压差（TVG）（26．0±2．3）mmHg（1mmHg=0．133kPa）。置人人工瓣膜35枚，其中机械瓣20枚，生物瓣15枚，瓣膜直径（23±1）mm。同期行二尖瓣成形术5例，三尖瓣成形术3例，冠状动脉旁路移植术4例。结果围手术期死亡3例。余者术后早期LVEF0．358±0．047，明显高于术前（P=0．008），术后6个月时LVEF0．426±0．031。术后早期LVEDD（5．7±0．4）cm，较术前减小，差异无统计学意义（P=0．062）；术后6个月，LVEDD（5．3±0．3）cm，与术前相比差异有显著意义（P〈0．01）。术后随访（35±23）个月，13例死亡。1、2、5年生存率分别为78％、68％、60％。死亡患者与生存患者比较，接受手术时年龄明显较大[（63±10）岁对（54±11）岁，P=0．017]；NYHA心功能分级明显较高[（3．9±0．2）级对（2．9±0．3）级，P=0．003）；术后LVEDD明显偏大[（6．0±1．0）cm对（5．5±0．3）cm，P=0．031]。多数患者术后症状改善明显，3～4级比例低于术前（P〈0．01）。结论虽然AVR手术具有较高的手术风险，但可以得到相对满意的手术及中、远期效果。受损的左心室心肌是否具有收缩储备能力可能是影响AVR手术效果的关键因素。

Objective To assess the result of aortic valve replacement（ AVR ）for patients of severe aortic stenosis（AS） with low transvalvular gradients（TVG） and severe left ventricular dysfunction, and try to identify the determinants of survival, functional status and change in left ventricular ejection fraction（LVEF） during follow-up. Methods From 2005 to 2011 , 35 patients with aortic valve area（AVA） 〈 1 cm2 , LVEF 〈 0.40 and mean TVG 〈 30 mm Hg underwent AVR in our hospital. The average age of the patients was 58 years old, and 88.6% of the patients were in New York Heart Association （NYHA） functional class III/IV at admission to the hospital. The AVA was （0.70 ± 0.09） cm2 , LVEF was 0. 276 ± 0. 020, TVG was （26. 0 ± 2.3 ） mm Hg, and left ventricular end-diastolic diameter （LVEDD） was （6.3 ± 0.4） cm respectively. 35 prosthetic valves were implanted, including 20 mechanical prostheses and 15 biological prostheses with the mean sizs of （23 ± 1 ） mm. Concomitant procedures included mitral valvularplasty in 5, tricuspid valve repair in 3 and coronary artery bypass grafting in 4. Results The perioperative mortality was 8.6%. Follow-up period was 3 to 60 monthes. The survival rates were： 1 -year 78 %, 2-year 68%, 5-year 60%. LVEF increased significantly to 0. 358 ± 0. 047 one week postoperatively （ P = 0. 008 ） and 0. 426 ±0.031 six months later （P 〈0.01 ） ）. LVEDD decreased to （5.7 ±0.4）era one week later（P =0. 062） and （5.3 ± 0.3 ） cm 6 months postoperatively （ P 〈 0. 01 ）. NYHA functional class improved from 88.6% in class III/IV to 35% （ P 〈 0.01 ）. Compared with those who survived during follow-up, the patients who died during follow-up were older in the year of operation [ （63 ± 10） vs （54 ± 11 ）, P =0. 017], their NYHA functional class was higher[ （3.9 ±0.2） vs （2.9±0. 3）,P = 0. 003 ] and the LVEDD for them in one week postoperatively was larger [ （ 6.0 ± 1.0 ） cm vs （ 5.5 ± 0. 3 ） cm, P = 0. 031 ]. Conclusion The left ventricle contractile reserve seems to play an essential role for surgery in patients of severe aortic stenosis with low transvalvular gradients and severe left ventrieular dysfunction. AVR can be performed for them with acceptable results.