Restenosis and Progression of Coronary Disease after Balloon Angioplasty in Patients with Diabetes Mellitus

BACKGROUND: Patients with diabetes mellitus (D) (both insulin-requiring D [IRD] and non-IRD) who undergo angioplasty have worse long-term outcome than do non-D patients. Few data are available in the literature that explain these findings. HYPOTHESIS: The study was undertaken to compare restenosis and progression of coronary disease after angioplasty in IRD patients, in non-IRD patients, and in non-D patients. METHODS: Diabetic patients who underwent coronary angioplasty were separated into two subgroups: IRD and non-IRD patients. Their angiographic outcome was compared with non-D patients. We examined retrospectively 353 coronary angiograms of patients who were referred for diagnostic angiography > 1 month after successful angioplasty. Quantitative angiography was used to determine the outcome in dilated narrowings (restenosis) and in nondilated narrowings (disease progression). RESULTS: Baseline clinical and angiographic characteristics were similar in all groups. Restenosis rate was higher in IRD (61%) than in non-IRD (36%) and non-D (35%) patients (p = 0.04). Late luminal loss after angioplasty was two times greater in IRD patients than in the other two groups (p = 0.01). Disease progression of nondilated narrowings was significantly more prominent in non-IRD than in non-D patients: Diameter stenoses were similar in the initial angiogram, but narrowings were significantly more severe (p = 0.02) in the final angiogram (70 +/- 27% and 60 +/- 33%, respectively). New narrowings were more common in non-IRD than in non-D patients: there was a 23% increase in the number of narrowings in the follow-up angiogram in non-IRD patients compared with only 12% in non-D patients (p < 0.003). These new narrowings were more common (p = 0.01) in angioplasty arteries (57 narrowings on 420 arteries--13.6%) than in nonangioplasty arteries (54 narrowings on 639 arteries--8.5%). CONCLUSION: Restenosis is more common in IRD patients and explains the high rate of adverse cardiac events within the first year after coronary intervention in these patients (mainly target lesion revascularization). Disease progression (including new narrowings) is the main determinant of patient outcome > 1 year after coronary intervention and is accelerated in non-IRD compared with non-D patients.