Cardiovascular Imaging and Hemodynamic Laboratory, Tufts Medical Center, Boston, Massachusetts 02111, USA.
JACC Cardiovasc Imaging. 2011 Aug;4(8):833-40. doi: 10.1016/j.jcmg.2011.03.019.
The purpose of this study was to examine whether left atrial (LA) mechanical function, as measured by LA total emptying fraction (TEF), is a predictor for the development of post-operative atrial fibrillation (POAF) following cardiac surgery.
POAF is an important and frequent complication of cardiac surgery. LA enlargement has been reported to be a risk factor for POAF, but the relationship between LA mechanical function and POAF is not well understood. We examined the relationship between pre-operative LA function and POAF in patients without a history of atrial fibrillation.
A total of 101 subjects (mean age 64 ± 13 years) underwent pre-operative transthoracic echocardiograms and were followed for occurrence of POAF during the hospitalization for cardiac surgery. The left atrial maximum volume (LAVmax) and left atrial minimum volume (LAVmin) were measured and indexed to body surface area (LAVmaxI and LAVminI, respectively). LA TEF was calculated as: {[(LAVmax - LAVmin)/LAVmax] × 100%}. Univariate and multivariate analyses examined clinical and echocardiographic predictors of POAF.
POAF occurred in 41% of subjects. Mean LA TEF was 49 ± 15%, mean LAVmaxI was 38 ± 15 ml/m(2), and mean LAVminI was 20 ± 13 ml/m(2). Age, LA TEF, and LAVminI were independent predictors of POAF. LA TEF was lower in patients with POAF compared with those without POAF (43 ± 15% vs. 55 ± 13%, p < 0.001), and patients with a LA TEF <50% had a high risk of POAF (odds ratio: 7.94, 95% confidence interval: 3.23 to 19.54, p < 0.001). Compared with LAVmaxI >32 ml/m(2), LA TEF <50% had higher discriminatory power for POAF, which remained significantly higher when adjusted for age (p = 0.04).
LA TEF is an independent predictor of POAF and is a stronger predictor of POAF than LAVmaxI is. Impaired LA mechanical function may help to identify patients who are most likely to benefit from prophylaxis for POAF.
本研究旨在探讨左心房（LA）机械功能（通过 LA 总排空分数（TEF）测量）是否可预测心脏手术后发生术后心房颤动（POAF）。
POAF 是心脏手术后的一种重要且常见的并发症。已有研究报道 LA 扩大是 POAF 的危险因素，但 LA 机械功能与 POAF 之间的关系尚不清楚。我们在无房颤病史的患者中检查了术前 LA 功能与 POAF 之间的关系。
共纳入 101 例患者（平均年龄 64±13 岁），在心脏手术住院期间，通过经胸超声心动图检查来观察 POAF 的发生情况。测量左心房最大容积（LAVmax）和左心房最小容积（LAVmin），并将其按体表面积指数化（分别为 LAVmaxI 和 LAVminI）。LA TEF 计算方法为：{[(LAVmax - LAVmin)/LAVmax] × 100%}。单变量和多变量分析检查了 POAF 的临床和超声心动图预测因素。
41%的患者发生了 POAF。平均 LA TEF 为 49±15%，平均 LAVmaxI 为 38±15ml/m²，平均 LAVminI 为 20±13ml/m²。年龄、LA TEF 和 LAVminI 是 POAF 的独立预测因素。与无 POAF 患者相比，POAF 患者的 LA TEF 较低（43±15% vs. 55±13%，p<0.001），且 LA TEF<50%的患者 POAF 风险较高（比值比：7.94，95%置信区间：3.23 至 19.54，p<0.001）。与 LAVmaxI>32ml/m²相比，LA TEF<50%对 POAF 的预测能力更高，且在调整年龄后仍具有显著差异（p=0.04）。
LA TEF 是 POAF 的独立预测因素，并且比 LAVmaxI 更能预测 POAF。LA 机械功能受损可能有助于识别最有可能从 POAF 预防中获益的患者。
