Long-term outcomes of coronary artery bypass grafting patients supported preoperatively with an intra-aortic balloon pump

Early and late outcomes of single versus bilateral internal thoracic artery revascularization for patients in critical condition

OBJECTIVE

The optimal surgical approach for critically ill patients with complex coronary disease remains uncertain. We compared outcomes of bilateral internal thoracic artery (BITA) versus single ITA (SITA) revascularization in critical patients.

METHODS

We evaluated 394 consecutive critical patients with multi-vessel disease who underwent CABG during 1996-2001. Outcomes measured were early mortality, strokes, myocardial-infarctions, sternal infections, revisions for bleeding, and late survival. The critical preoperative state was acknowledged concisely by one or more of the following: preoperative ventricular tachycardia/fibrillation, aborted sudden cardiac death, or the need for mechanical ventilation or for preoperative insertion of intra-aortic-balloon counter-pulsation.

RESULTS

During the study period, 193 of our patients who underwent SITA and 201 who underwent BITA were in critical condition. The SITA group was older (mean 68.0 vs. 63.3 years, p = 0.001) and higher proportions were females (28.5% vs. 18.9% p = 0.025), after recent-MI (69.9% vs. 57.2% p = 0.009) and with left-main disease (38.3% vs. 49.3% p = .029); the median logistic EuroSCORE was higher (0.2898 vs. 0.1597, p<0.001). No statistically significant differences were observed between the SITA and BITA groups in 30-day mortality; and in rates of early CVA, MI and sternal infections (13.0% vs. 8.5%, p = 0.148; 4.1% vs. 6.0%, p = 0.49; 6.7% vs. 4.5%, p = 0.32 and 2.1% vs. 2.5%, p>0.99, respectively). Long-term survival (median follow-up of 15 years, interquartile-range: 13.57-15) was better in the BITA group (median 14.39 vs. 9.31± 0.9 years, p = 0.001). Propensity-score matching (132 matched pairs) also yielded similar early outcomes and improved long-term survival (median follow-up of 15 years, interquartile-range: 13.56-15) for the BITA group (median 12.49±1.71 vs. 7.63±0.99 years, p = 0.002). In multivariable analysis, BITA revascularization was found to be a predictor for improved survival (hazard-ratio of 0.419, 95%CI 0.23-0.76, p = 0.004).

CONCLUSIONS

This study demonstrated long-term survival benefit for BITA revascularization in patients in a critical pre-operative state who presented for surgical revascularization.

Higher Mortality in Women after Coronary Artery Bypass: Meta-analysis & Bias Analysis of Confounding

BACKGROUND

Some studies suggest the observed higher mortality in women than men after coronary artery bypass grafting (CABG) is due to confounding. Our meta-analysis aimed to 1) summarize the effect of sex on mortality following CABG and 2) identify whether unmeasured confounding likely explains the apparent higher mortality in women.

METHODS

MEDLINE, Embase, and CENTRAL databases were searched for studies examining sex and 30-day mortality following CABG. We used random-effects meta-analysis to estimate the summary odds ratio (OR) of mortality in women versus men using 1) unadjusted study results and 2) adjusted study results. Available confounders data from included studies was identified. Using the OR of measured confounders and the risk of death to inform unmeasured confounding effects, we performed bias analysis simulation to correct potential unmeasured confounding in our summary OR.

RESULTS

From 7138 retrieved studies, 112 were included (N=5,008,262 patients), 25 studies reported adjusted OR (N=770,450 patients). The overall 30-day mortality was 4.9% in women vs. 3.3% in men. The unadjusted summary OR (1.81, 95% CI 1.72 to 1.91) and adjusted summary OR (1.40, 95% CI 1.35 to 1.45) demonstrated that women had an increased risk of 30-day mortality compared to men. Simulations correcting for unmeasured confounding that mostly ranged from 1.05 to 1.80, supporting a higher risk of death in women after CABG.

CONCLUSIONS

The findings of this review suggest confounding is unlikely to account for the increased risk of mortality in women after CABG and that biological factors have a casual effect.

Emergency Coronary Artery Bypass Grafting: Indications and Outcomes from 2003 through 2013

Emergency coronary artery bypass grafting (CABG) is associated with increased in-hospital mortality rates and adverse events. This study retrospectively evaluated indications and outcomes in patients who underwent emergency CABG. The Society of Thoracic Surgeons database for a single center (Jewish Hospital) was queried to identify patients undergoing isolated CABG. Univariate analysis was performed. From January 2003 through December 2013, 5,940 patients underwent CABG; 212 presented with emergency status. A high proportion of female patients (28.2%) underwent emergency surgery. Emergency CABG patients experienced high rates of intra-aortic balloon pump support, bleeding, dialysis, in-hospital death, and prolonged length of stay. The proportion of emergency coronary artery bypass grafting declined during years 2008-2013 compared with 2003-2007 (2.2% vs. 4.5%, P < 0.001), but the incidence of angiographic accident (5.3% vs. 29.2%) increased as an indication. Ongoing ischemia remains the most frequent indication for emergency CABG, yet the incidence of angiographic accident has greatly increased. In-hospital mortality rates and adverse events remain high. If we look specifically at emergency CABG cases arising from angiographic accident, we find that 14 (15%) of all 93 emergency CABG deaths occurred in that subset of patients. Efforts to improve outcomes should therefore be focused on this high-risk group.

Temporal Trends of In-Hospital Mortality in Patients Treated with Intra-Aortic Balloon Pumping: A Nationwide Population Study in Taiwan, 1998-2008

Intra-aortic balloon pumping (IABP) is widely used for hemodynamic support in critical patients with cardiogenic shock (CS). We examined whether the in-hospital mortality of patients in Taiwan treated with IABP has recently declined. We used Taiwan’s National Health Insurance Research Database to retrospectively review the in-hospital all-cause mortality of 9952 (7146 men [71.8%]) 18-year-old and older patients treated with IABP between 1998 and 2008. The mortality rate was 13.84% (n = 1377). The urbanization levels of the hospitals, and the number of days in the intensive care unit, of hospitalization, and of IABP treatment, and prior percutaneous coronary intervention (PCI) were associated with mortality. Seven thousand six hundred thirty-five patients (76.72%) underwent coronary artery bypass grafting (CABG) surgery, and 576 (5.79%) underwent high-risk PCI with IABP treatment. The number of patients treated with IABP significantly increased during this decade (p_trend < 0.0001), the in-hospital all-cause mortality for patients treated with IABP significantly decreased (p_trend = 0.0243), but the in-hospital all-cause mortality of patients who underwent CABG and PCI plus IABP did not decrease. In conclusion, the in-hospital mortality rate of IABP treatment decreased annually in Taiwan during the study period. However, high-risk patients who underwent coronary revascularization with IABP had a higher and unstable in-hospital mortality rate.