Sex differences in resource use after on-pump and off-pump coronary artery bypass surgery: A propensity score-matched cohort

Abstract

B eating heart revascularization gained popularity several years previously as an attractive method to reduce the morbidity and mortality associated with cardiopulmonary bypass surgery (CPB). As technological advances improved the ability of surgeons to reproduce the results of 'off-pump' coronary artery bypass surgery (OPCAB), several clinical trials were initiated to compare the early clinical outcomes of OPCAB with those of standard myocardial revascularization using a CPB circuit (on-pump coronary artery bypass surgery [ONCAB]).While the majority of observational studies favoured clinical outcomes following OPCAB, these results were not substantiated in subsequent randomized clinical trials. Indeed, a recent meta-analysis (1) suggested very little benefit of OPCAB over conventional ONCAB. Despite these findings, most surgeons continue to believe that OPCAB is beneficial in certain high-risk subgroups. The present study examined whether there are sex-specific benefits of OPCAB, particularly with respect to hospital resource use. To adjust for the selected nature of OPCAB patients, a propensity score analysis was performed to match male and female cohorts with standard preoperative demographic characteristics. The present study demonstrates that the potential beneficial effects of OPCAB are not observed in female patients. In contrast, there were significant benefits in resource use for male patients undergoing isolated myocardial revascularization using an off-pump technique. BACkgROunD: Previous studies have demonstrated that off-pump coronary artery bypass surgery (OPCAB) is associated with less use of hospital resources compared with on-pump coronary artery bypass surgery (ONCAB). OBJECTiVE: To determine whether there is a sex effect between the two procedures regarding resource utilization. METHODS: Between 1996 and 2004, 13,522 patients (10,637 men and 2885 women) underwent coronary artery bypass grafting surgery at the Toronto General Hospital (Toronto, Ontario). Among the men, 10,121 patients underwent ONCAB and 516 underwent OPCAB. The female population consisted of 2723 ONCAB and 162 OPCAB patients. Both groups were matched to standard preoperative risk factors. A propensity score macro-matched 471 OPCAB men to 471 ONCAB men, and 148 OPCAB women to 148 ONCAB women. RESuLTS: The mean (± SD) postoperative length of stay (7.5±6.5 days versus 6.4±5.5 days; P<0.0001) was significantly higher in ONCAB compared with OPCAB in the male population. The mean length of stay in the intensive care unit and the mean ventilation time was similar between the groups. However, in the female population, there were no differences in mean posoperative length of stay (8±5.9 days versus 8±6 days; P=0.4), mean length of stay in the intensive care unit (43±38 h versus 53±81 h; P=0.4) or mean ventilation time (9.8±9.7 h versus 11±13 h; P=0.8). COnCLuSiOn: These results suggest that the benefits of OPCAB in terms of hospital resource use are influenced by sex. The potential beneficial effects are not demonstrated in the female ...

Off-pump versus on-pump revascularization in females: a meta-analysis of observational studies

“…Our search revealed eight studies fulfilling our inclusion criteria; [18][19][20][21][22][23][24][25] however, two were found to report duplicate data and were, therefore, excluded from our analysis (Figure 1). 24,25 The remaining six studies which were included incorporated 23,313 patients of whom 9596 underwent OPCAB and 13717 underwent ONCAB.…”

“…Five studies [18][19][20][21][22] reported the rate of peri/post-operative MI, which was statistically lower in the OPCAB group compared to ONCAB (1% vs. 1.9%; OR 0.65; 95%CI [0.51, 0.84], p=0.0009) without significant heterogeneity in either overall or subgroup analysis (Figure 2b).…”

“…Furthermore, risk adjustment for differences in pre-operative characteristics between ONCAB and OPCAB was only performed in two of these reports. 20,21 Due to the retrospective nature of these studies, inclusion criteria were also less robust, leading to a significant risk of selection bias. As such, no studies reported their criteria for defining myocardial infarction in either the pre-or the post-operative period, potentially introducing unquantifiable differences in pre-operative risk and generating heterogeneity in the post-operative MI outcome.…”

Left Ventricular Aneurysm Repair: Off-pump Linear Plication versus On-pump Patch Plasty

“…And the clinical outcomes might be more likely to be achieved with total revascularization and LIMA to the LAD [12] . In recent years, off-pump CABG, an effective surgical technique, has been demonstrated to benefit particularly the high-risk population, because this technique avoids the manipulation of the CPB and eliminates complications secondary to CPB [13,14] . Off-pump linear plication combined with off-pump CABG may be an acceptable strategy for patients with postinfraction LVA.…”