RESUMO
OBJECTIVE: Postoperative atrial fibrillation (POAF) is associated with increased morbidity, mortality, and length of hospital stay. The objective of this study was to assess the utility of left atrial strain (LAS) to predict POAF in patients undergoing off-pump coronary artery bypass grafting (OPCABG). DESIGN: Retrospective observational study. SETTING: Tertiary care hospital. PARTICIPANTS: 103 patients undergoing OPCABG. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: In addition to comprehensive transthoracic echocardiography, LAS was measured for reservoir (R), conduction (CD), and contraction (CT) components. POAF was defined as new electrocardiographic evidence of AF requiring treatment. Logistic regression was done to assess factors associated with POAF. The diagnostic accuracy of variables in predicting POAF was assessed by receiver operating characteristic analysis. POAF was documented in 24 (23.3%) patients. There was no difference in ejection fraction, average global longitudinal strain, or proportion of left ventricular diastolic dysfunction grades between patients with POAF and patients without POAF. All three components of LAS: LAS R (19.2 ± 4.7 v 23.5 ± 4.8, p < 0.001), LAS CD (8.9 ± 3.7 v 12.3 ± 4.8, p = 0.1), and LAS CT (10.3 ± 3.9 v 12.1 ± 4.1, p = 0.04), were significantly lower among patients with POAF compared with patients without POAF, respectively. According to univariate analysis, all components of LAS were statistically significant predictors of POAF. In multivariate analysis, only age (odds ratio = 1.08, p = 0.025) and LAS R (odds ratio = 0.84, p = 0.004) were independently associated with POAF. LAS R was a better predictor of POAF, with an area under the curve (AUC) of 0.758, than LAS CD (AUC = 0.67) and LAS CT (AUC = 0.62). LAS R had an optimal cutoff of 23% with sensitivity of 95.8% (confidence interval: 78.9-99.9%) and specificity of 49.4% (37.9-60.9%) to predict POAF. CONCLUSIONS: LAS R is a significant predictor of POAF, and its use can be recommended for screening of OPCABG patients at high risk of POAF.
RESUMO
During surgery for colorectal cancer, the inferior mesenteric artery (IMA) may be ligated either directly at the origin of the IMA from the aorta (high ligation) or at a point just below the origin of the left colic artery (low ligation). Sixty patients of left colonic and rectal cancer undergoing elective curative surgery in 2007 and 2008 were selected for this observational study. The resected lymph nodes were grouped into three levels: along the bowel wall (D1), along IMA below left colic (D2), and along the IMA and its root (D3). Statistical analysis was performed with SPSS version 20.0. D2 level was involved pathologically in 20 (33.3 %) and D3 in six out of 44 (13.6 %) patients. The median nodal yield with high and low ligation were 33 and 25, respectively (p = 0.048). Median overall survival for high ligation was 62 months versus 42 months for low ligation (p = 0.190). High ligation of the IMA for rectal and left colonic cancers can improve lymph node yield, thus facilitating accurate tumor staging and thus better disease prognostication, but the survival benefit is not significant.