Coronary revascularization (surgical or percutaneous) decreases mortality after the first year in diabetic subjects but not in nondiabetic subjects with multivessel disease: an analysis from the Medicine, Angioplasty, or Surgery Study (MASS II).

BACKGROUND

It is currently unknown whether revascularization procedures are associated with an improvement in mortality among diabetic subjects, as compared with a more conservative medical treatment.

METHODS AND RESULTS

In MASS II, a total of 611 patients with stable multivessel coronary disease were randomly assigned to medical treatment, surgery, or angioplasty. From these, 190 patients had diabetes (medical, 75 patients; angioplasty, 56 patients; surgery, 59 patients) and comprised the present study population. Mortality rates were analyzed for the entire 5 years of follow-up. Separate analyzes were also performed for mortality at 2 time intervals: during the first year and after the first year of follow-up. We calculated the probability of death conditional on surviving to the start of the interval analyzed. The cumulative 5-year mortality as well as the mortality during the first year of follow-up was not significantly different among treatment groups, both for diabetic and for nondiabetic subjects. Also, during years 2 to 5, the mortality of the 3 treatment groups was not different for nondiabetic subjects. Among diabetic subjects, however, patients randomized to angioplasty or surgery had a significantly lower mortality between years 2 and 5 than those allocated to medical treatment (P=0.039).

CONCLUSIONS

Surgery, angioplasty, and medical treatment appear to be associated with similar mortality rates for non-diabetic subjects. For diabetic subjects, however, coronary revascularization (percutaneous or surgical) significantly decreased the risk of death after the first year and up to 5 years, compared with medical treatment alone.