Pegg Tammy J, Selvanayagam Joseph B, Francis Jane M, Karamitsos Theodoros D, Maunsell Zoe, Yu Ly-Mee, Neubauer Stefan, Taggart David P
Department of Cardiology, Flinders Dr, Flinders Medical Centre, Bedford Park SA5042, Australia.
Circulation. 2008 Nov 18;118(21):2130-8. doi: 10.1161/CIRCULATIONAHA.108.785105. Epub 2008 Nov 3.
Beating heart coronary artery bypass grafting (CABG) improves early postoperative cardiac function in patients with normal ventricular function, but its effect in patients with impaired function is uncertain. We compared a novel hybrid technique of on-pump beating heart CABG (ONBEAT) with conventional on-pump CABG (ONSTOP) in patients with impaired ventricular function.
In a single-center randomized trial, 50 patients with impaired ventricular function were randomly assigned to ONBEAT or ONSTOP. Patients underwent cardiac magnetic resonance imaging for function and delayed hyperenhancement early and later after surgery. Serial assessment of biochemical markers was also undertaken. Preoperative characteristics were well matched; cardiac index was 2.85+/-0.53 (ONBEAT) and 2.62+/-0.59 L x min(-1) x m(-2) (ONSTOP). Early after surgery, there was a trend toward a greater reduction in end-systolic volume index in ONSTOP patients versus ONBEAT (-9+/-8 versus -4+/-11 mL x m(-2); P=0.06). The changes were sustained and significant at 6 months (-14+/-18 versus -2+/-19 mL x m(-2); P=0.04). Furthermore, the incidence of new hyperenhancement at 6 days was higher in ONBEAT patients (P=0.05), with 6 of 17 (35%) sustaining 8.2+/-5.2 g of new hyperenhancement each versus 2 of 23 (9%) in the ONSTOP group, each with 9.8+/-9.0 g (P=0.86). Finally, median area under the curve for troponin was higher in ONBEAT at 461 (interquartile range, 226 to 1141) microg/L versus 160 (interquartile range, 98 to 357) microg/L for ONSTOP (P=0.002).
The incidence of new irreversible myocardial injury was significantly higher in ONBEAT than in ONSTOP patients. Furthermore, at 6 months, only ONSTOP patients demonstrated an improvement in ventricular geometry. The most likely mechanism is inadequate coronary perfusion to distal myocardial territories in patients with severe proximal coronary disease.
心脏不停跳冠状动脉搭桥术（CABG）可改善心室功能正常患者术后早期的心功能，但其对心功能受损患者的效果尚不确定。我们比较了一种新型的体外循环心脏不停跳CABG（ONBEAT）与传统体外循环CABG（ONSTOP）在心室功能受损患者中的疗效。
在一项单中心随机试验中，50例心室功能受损患者被随机分配至ONBEAT组或ONSTOP组。患者在术后早期及后期接受心脏磁共振成像以评估心功能及延迟强化情况。同时进行生化标志物的系列评估。术前特征匹配良好；心脏指数在ONBEAT组为2.85±0.53，在ONSTOP组为2.62±0.59L·min⁻¹·m⁻²。术后早期，ONSTOP组患者的收缩末期容积指数下降幅度有大于ONBEAT组的趋势（-9±8 vs -4±11mL·m⁻²；P=0.06）。这种变化在6个月时持续存在且具有显著性差异（-14±18 vs -2±19mL·m⁻²；P=0.04）。此外，ONBEAT组患者在术后6天时新出现延迟强化的发生率更高（P=0.05），ONBEAT组17例中有6例（35%）持续出现8.2±5.2g的新延迟强化，而ONSTOP组23例中有2例（9%）出现，分别为9.8±9.0g（P=0.86）。最后，ONBEAT组肌钙蛋白曲线下面积中位数为461（四分位间距，226至1141）μg/L，高于ONSTOP组的160（四分位间距，98至357）μg/L（P=0.002）。
ONBEAT组患者新发生的不可逆心肌损伤发生率显著高于ONSTOP组。此外，在6个月时，只有ONSTOP组患者的心室几何形态得到改善。最可能的机制是严重近端冠状动脉疾病患者的远端心肌区域冠状动脉灌注不足。
