Open Access Research article

Prevalence of Dysglycemia Among Coronary Artery Bypass Surgery Patients with No Previous Diabetic History

Joseph T McGinn12, Masood A Shariff1*, Tariq M Bhat3, Basem Azab3, William J Molloy1, Elaena Quattrocchi14, Mina Farid1, Ann M Eichorn5, Yosef D Dlugacz5 and Robert A Silverman567

Author Affiliations

1 Cardiothoracic Surgery Department, Heart Institute at Staten Island University Hospital, 475 Seaview Ave, Staten Island, New York, USA

2 State University of New York Health Science Center at Brooklyn, 450 Clarkson Avenue, Brooklyn, New York, USA

3 Department of Internal Medicine, Staten Island University Hospital, 475 Seaview Ave, Staten Island, New York, USA

4 Pharmacy Clinic, Long Island University, Brooklyn, New York, USA

5 Krasnoff Quality Management Institute, North Shore-Long Island Jewish Health System, 600 Northern Boulevard, Great Neck, New York, USA

6 Department of Emergency Medicine, Long Island Jewish Medical Center, North Shore-Long Island Jewish Health System, 270-05 76th Avenue, New Hyde Park, New York, USA

7 Hofstra North Shore-LIJ School of Medicine, Hofstra University, Hempstead, New York, USA

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Journal of Cardiothoracic Surgery 2011, 6:104  doi:10.1186/1749-8090-6-104

Published: 2 September 2011

Abstract

Background

Dysglycemia is a major risk factor for atherosclerosis. In many patient populations dysglycemia is under-diagnosed. Patients with severe coronary artery disease commonly have dysglycemia and there is growing evidence that dysglycemia, irrespective of underlying history of diabetes, is associated with adverse outcome in coronary artery bypass graft (CABG) surgery patients, including longer hospital stay, wound infections, and higher mortality. As HbA1c is an easy and reliable way of checking for dysglycemia we routinely screen all patients undergoing CABG for elevations in HbA1c. Our hypothesis was that a substantial number of patients with dysglycemia that could be identified at the time of cardiothoracic surgery despite having no apparent history of diabetes.

Methods

1045 consecutive patients undergoing CABG between 2007 and 2009 had HbA1c measured pre-operatively. The 2010 American Diabetes Association (ADA) diagnostic guidelines were used to categorize patients with no known history of diabetes as having diabetes (HbA1c ≥ 6.5%) or increased risk for diabetes (HbA1c 5.7-6.4%).

Results

Of the 1045 patients with pre-operative HbA1c measurements, 40% (n = 415) had a known history of diabetes and 60% (n = 630) had no known history of diabetes. For the 630 patients with no known diabetic history: 207 (32.9%) had a normal HbA1c (< 5.7%); 356 (56.5%) had an HbA1c falling in the increased risk for diabetes range (5.7-6.4%); and 67 (10.6%) had an HbA1c in the diabetes range (6.5% or higher). In this study the only conventional risk factor that was predictive of high HbA1c was BMI. We also found a high HbA1c irrespective of history of DM was associated with severe coronary artery disease as indicated by the number of vessels revascularized.

Conclusion

Among individuals undergoing CABG with no known history of diabetes, there is a substantial amount of undiagnosed dysglycemia. Even though labeling these patients as "diabetic" or "increased risk for diabetes" remains controversial in terms of perioperative management, pre-operative screening could lead to appropriate post-operative follow up to mitigate short-term adverse outcome and provide high priority medical referrals of this at risk population.

Keywords:
HbA1c; coronary artery bypass grafting (CABG); coronary artery disease (CAD); dysglycemia; increased risk of diabetes; diabetes