Y. Sanaiha1, Y. Juo1, K. Bailey1, E. Aguayo1, A. Iyengar1, V. Dobaria1, Y. Seo1, B. Ziaeian2, P. Benharash1 1David Geffen School Of Medicine, University Of California At Los Angeles,Cardiac Surgery,Los Angeles, CA, USA 2David Geffen School Of Medicine, University Of California At Los Angeles,Cardiology,Los Angeles, CA, USA
Introduction:
Cardiovascular complications are the leading cause of death following noncardiac surgery. Major abdominal operations represent the largest category of procedures considered to have elevated risk of cardiovascular complications. The current aim was to examine trends in the incidence of mortality, postoperative myocardial infarction, and cardiac arrest after major abdominal operations and to determine the presence of potential volume-outcome relationships.
Methods:
We performed a retrospective analysis of the Nationwide Inpatient Sample (NIS) for patients having elective open gastrectomy, pancreatectomy, nephrectomy, splenectomy, and colectomy (major abdominal surgery: “MAS”) during 2008-2014. Chi-squared analysis was used to compare demographic and hospital characteristics between groups. Logistic regression was performed to determine predictors of in-hospital mortality, postoperative cardiac arrest (POCA) and myocardial infarction (POMI).
Results:
Of the 1,300,794 patients undergoing MAS, 49,589(3.70%) experienced in-hospital mortality, 16,542 (1.24%) POMI, and 9,496 (0.76%) POCA. The annual all-cause mortality and POMI rates remained stable while the incidence of POCA steadily rose. Average Elixhauser score also increased from 1.8 to 2.2 during this study period. Odds of mortality were significantly lower for medium and large volume hospitals compared to small volume hospitals after adjustment (Table). Hospital operative volume did not significantly impact the odds of POMI or POCA. In contrast, larger hospital bedsize was associated with higher odds of mortality and POCA. Subgroup analysis demonstrated lower odds of mortality with higher operative volume over 2008-2014 for all operations except for splenectomy. Significant risk factors for POMI/POCA included age > 65, peripheral vascular disease, and congestive heart failure, while female gender and higher income quartile had decreased odds of these complications (P<0.02).
Conclusion:
The rate of POCA amongst patients having MAS has increased in the US without a concomitant rise in POMI or mortality. Hospital operative volume appears to reduce odds of postoperative mortality over the entire study period. The effect of operative volume on rate of postoperative cardiac complications is not consistent over time as odds of POCA are significantly lower for higher volume hospitals only in 2008-2011 population. Operative volume does not significantly impact risk of POMI or POCA in the 2012-2014 subgroup. Increased odds of mortality and POCA at larger hospitals by bedsize could reflect patient or hospital factors that are not well represented in NIS. Non-ischemic causes of POCA need further investigation to delineate opportunities for quality improvement.
