Results
A total of 67,568 patients were identified who were ≥70 years old and older and underwent CABG. The data from our study shows that patients who were octogenarians had worse results (Figure 2). Specifically, compared to the Septuagenarians, the Octogenarians were more likely to develop more cardiac complications (OR [odds ratio] =1.20, 95% CI [confidence interval] 1.12-1.23. They were also more likely to develop more renal complications (OR 1.54 95% CI 1.48-1.61, P <0001), respiratory complications (OR 1.2, 95% CI 1.2-2.1, P <0001), and infectious complications (OR=1.41, 95% CI 1.34-1.48, P <0001). These complications lead to poor surgical outcomes. Our results are supported by previous studies with similar findings that older patients have worse results compared to younger patients. The unique study design was to separate elderly patients into Septuagenarians and Octogenarians allowing for the identification of important differences in outcomes.
In a study analyzing 8769 patients undergoing cardiac surgery, patients over the age of 70 were observed to have increased risk of postoperative complications including pneumonia, arrhythmia, and bleeding [4]. Similarly, a study published in 2011 demonstrated that risk factors for reoperation due to bleeding were related to older age [8]. As older patients undergo CABG, it is very useful to be able to risk stratify these patients and identify which age group above 70 years old have better outcomes and should be directed to CABG. Conversely, identifying which patients have worse outcomes can help steer these patients towards PCI.
The Octogenarians in our study were also more likely to bleed postoperatively (P <0.0001), and they had a higher mortality (OR 1.41 95% CI 1.36-1.61, P <0001) (Figure 3). Moreover, the older patients had a longer postoperative LOS (median 9 days IQR [interquartile range] 7-13 days compared to the Septuagenarians (median 8 days IQR 6-11 days). As expected with the longer LOS, the Octogenarians had an associated increased hospital cost (median $39,152 IQR $30, 0003.84 - $53, 272.84) compared to the Septuagenarians (median $35,996.16 IQR $27,735.94 - $48,134.38) (Figure 4 and 5). Furthermore, the female octogenarians had a higher mortality (OR 1.25 95% CI 1.07–1.46) compared to males in the same age group (Figure 1). The gender difference in the Octogenarians is a critical finding not previously reported in the literature. These worse outcomes for female Octogenarians extended to more postoperative complications including bleeding, respiratory complications, and infections (Figure 6-8).