The diabetic disadvantage: historical outcomes measures in diabetic patients undergoing cardiac surgery -- the pre-intravenous insulin era.

Seven percent of the United States population is diabetic. However, diabetics are two to five times more likely to develop cardiovascular disease and therefore populate 30% of open heart procedures in this country. In addition, it has been well documented that diabetic cardiac surgery patients are further disadvantaged with worse outcomes following those procedures. This has been termed the "Diabetic Disadvantage." To benchmark these specific disadvantages, we evaluated the short- and long-term outcomes for diabetics and nondiabetics undergoing coronary artery bypass graft (CABG), CABG/valve, and aortic or mitral valve replacement surgery before the broader acceptance and use of intravenous insulin infusions in this patient population in 2001. All such patient records (n = 1,369,961) from the Society of Thoracic Surgeons national database operated on between 1990 and 2000 were assessed for short-term outcomes. Ten-year survival was evaluated among 36,835 patients from the Northern New England Cardiovascular Disease Study Group longitudinal registry. The diabetic population was found to have higher rates of 30-day mortality, deep sternal wound infection, stroke, and longer length of stay than the nondiabetic population. In addition, diabetic patients had approximately two-fold worse 10-year survival. All differences were statistically significant (P < 0.001). In summary, The Diabetic Disadvantage in the pre-intravenous insulin era is characterized by worse short- and long-term outcomes for diabetic patients undergoing cardiac surgery in the United States and Canada.