Sitges Marta, Vidal Barbara, Delgado Victoria, Mont Lluis, Garcia-Alvarez Ana, Tolosana Jose M, Castel Angeles, Berruezo Antonio, Azqueta Manel, Pare Carles, Brugada Josep
Thorax Clinic Institute, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain.
Am J Cardiol. 2009 Aug 1;104(3):383-8. doi: 10.1016/j.amjcard.2009.03.060. Epub 2009 Jun 6.
Cardiac resynchronization therapy (CRT) has been shown to reduce functional mitral regurgitation (MR). The aims of this study were to analyze the underlying mechanisms leading to this reduction and to identify the best candidates with functional MR for this therapy. Changes in mitral geometry, left ventricular (LV) remodeling, and LV synchrony were studied in patients who underwent CRT acutely and at 6- and 12-month follow-up. Of 151 patients (mean age 69 +/- 9 years, 82% men) who underwent CRT, 57 (38%) had nontrivial MR (regurgitant orifice area > or =10 mm(2)). The median reduction of MR with CRT was 18% acutely and 38% at 12-month follow-up. CRT induced an acute improvement in LV systolic function (LV dP/dt from 508 +/- 143 to 700 +/- 249 mm Hg, p <0.05) and a reduction in dyssynchrony (interventricular delay from 51 +/- 31 to 29 +/- 27 ms, p <0.05). At 12-month follow-up, additional reverse global and local LV remodeling (LV end-systolic volume from 183 +/- 77 to 151 +/- 50 ml, tenting area from 3.36 +/- 0.98 to 2.78 +/- 0.75 cm, p <0.05 for both) and a reduction in LV dyssynchrony (septal-lateral delay from 90 +/- 63 to 53 +/- 42 ms, p <0.05) were found. Significant reductions in MR were found in 28 patients (49%) and similarly observed in either ischemic MR or functional MR of other causes. Baseline mitral tenting area was the strongest predictor of significant MR reduction with CRT. In conclusion, CRT induced acute and sustained reductions in functional MR in almost 50% of patients by initially improving LV systolic function and dyssynchrony; long-term reverse LV remodeling contributed to this sustained effect. Patients with larger mitral valve tenting areas are less amenable to benefit from CRT.
心脏再同步治疗（CRT）已被证明可减少功能性二尖瓣反流（MR）。本研究的目的是分析导致这种减少的潜在机制，并确定最适合接受这种治疗的功能性MR患者。对接受CRT治疗的患者在急性治疗时以及随访6个月和12个月时的二尖瓣几何形状、左心室（LV）重构和LV同步性变化进行了研究。在151例接受CRT治疗的患者（平均年龄69±9岁，82%为男性）中，57例（38%）有显著MR（反流口面积≥10 mm²）。CRT治疗后，MR的中位数急性减少18%，随访12个月时减少38%。CRT使LV收缩功能急性改善（LV dP/dt从508±143 mmHg增至700±249 mmHg，p<0.05），并减少了不同步性（室间延迟从51±31 ms降至29±27 ms，p<0.05）。在随访12个月时，发现有额外的整体和局部LV逆向重构（LV收缩末期容积从183±77 ml降至151±50 ml，帐篷面积从3.36±0.98 cm降至2.78±0.75 cm，两者p均<0.05）以及LV不同步性降低（室间隔-侧壁延迟从90±63 ms降至53±42 ms，p<0.05）。28例患者（49%）的MR显著降低，在缺血性MR或其他原因的功能性MR中也有类似观察结果。基线二尖瓣帐篷面积是CRT治疗后MR显著降低的最强预测因素。总之，CRT通过最初改善LV收缩功能和不同步性，使近50%的患者功能性MR急性和持续降低；长期的LV逆向重构促成了这种持续效应。二尖瓣帐篷面积较大的患者从CRT中获益较少。
