Impact of Diabetes on 10-Year Outcomes of Patients With Multivessel Coronary Artery Disease in the Medicine, Angioplasty, or Surgery Study II (MASS II) Trial

Eduardo Gomes Lima, MD; Whady Hueb, MD, PhD; Rosa Maria Rahmi Garcia,MD, PhD; Alexandre Costa Pereira,MD, PhD; Paulo Rogério Soares, MD, PhD; Desiderio Favarato, MD, PhD; Cibele Larrosa Garzillo, MD, PhD; Ricardo D'Oliveira Vieira, MD; Paulo Cury Rezende, MD; Myrthes Takiuti, RN, PhD; Priscyla Girardi, RN, PhD; Alexandre Ciappina Hueb, MD, PhD; José A. F. Ramires, MD, PhD; Roberto Kalil Filho,MD, PhD


Am Heart J. 2013;166(2):250-257. 

In This Article

Abstract and Introduction


Introduction Diabetes mellitus is a major cause of coronary artery disease (CAD). Despite improvement in the management of patients with stable CAD, diabetes remains a major cause of increased morbidity and mortality. There is no conclusive evidence that either modality is better than medical therapy alone for the treatment of stable multivessel CAD in patients with diabetes in a very long-term follow-up. Our aim was to compare 3 therapeutic strategies for stable multivessel CAD in a diabetic population and non-diabetic population.
Methods It was compared medical therapy (MT), percutaneous coronary intervention (PCI), and coronary artery bypass graft (CABG) in 232 diabetic patients and 379 nondiabetic patients with multivessel CAD. Endpoints evaluated were overall and cardiac mortality.
Results Patients (n = 611) were randomized to CABG (n = 203), PCI (n = 205), or MT (n = 203). In a 10-year follow-up, more deaths occurred among patients with diabetes than among patients without diabetes (P = .001) for overall mortality. In this follow-up, 10-year mortality rates were 32.3% and 23.2% for diabetics and non-diabetics respectively (P = .024). Regarding cardiac mortality, 10-year cardiac mortality rates were 19.4% and 12.7% respectively (P = .031).Considering only diabetic patients and stratifying this population by treatment option, we found mortality rates of 31.3% for PCI, 27.5% for CABG and 37.5% for MT (P = .015 for CABG vs MT) and cardiac mortality rates of 18.8%, 12.5% and 26.1% respectively (P = .005 for CABG vs MT).
Conclusions/interpretation Among patients with stable multivessel CAD and preserved left ventricular ejection fraction, the 3 therapeutic regimens had high rates of overall and cardiac-related deaths among diabetic compared with non-diabetic patients. Moreover, better outcomes were observed in diabetic patients undergoing CABG compared to MT in relation to overall and cardiac mortality in a 10-year follow-up.


Diabetes is a known condition associated with coronary artery disease (CAD). Its role as a promoter of atherosclerosis has been described, and diabetes has been associated with a greater plaque burden,[1,2] more diseased coronary segments,[3] and more complex coronary lesions.[4–6]

Previous studies have found that diabetic patients with CAD have a worse prognosis than non-diabetic patients with CAD regarding major adverse cardiovascular events[7] even when they undergo a revascularization procedure.[8] In the last decade, the BARI study[9] demonstrated, in a subgroup analysis, a lower rate of mortality in diabetic patients who were assigned to coronary artery bypass graft (CABG) compared to those who underwent balloon angioplasty. The difference in long-term mortality between the study groups was mostly explained by the larger degree of completeness of revascularization in the surgical arm, compared with patients randomized to balloon angioplasty. There was no exclusive medical treatment arm in this study.

After that, larger trials were designed to specifically study the diabetic population, such as BARI 2D.[10] No difference in mortality was observed comparing intervention with CABG or PCI using bare metal stents (BMS) with no intervention. More recently, the FREEDOM Trial[11] found significant higher mortality rates in diabetic patients undergoing PCI using drug eluting stents (DES) compared to patients undergoing CABG. Other studies directed to answer these questions have conflicting results. A collaborative analysis of individual patient data from 10 randomized trials comparing CABG to PCI using BMS in multivessel CAD found a significantly higher rate of mortality was found in the PCI group compared to the CABG group among diabetic patients but not in non-diabetic patients.[12] Even when we consider most recent studies comparing DES to CABG, results are conflicting and the length of follow-up is still short to answer these questions.[11,13] Thus, there is uncertainty regarding the best treatment option for multivessel CAD among diabetic patients regarding mortality in a very long-term follow-up.

In this study, we aimed to analyze the 10-year mortality rates in patients with and without diabetes randomized to 3 different treatment regimens in the MASS II trial.