Abnormal glucose tolerance, not small vessel diameter, is a determinant oflong-term prognosis in patients treated with balloon coronary angioplasty

Aims We sought to find out what factors are important for long-term prognos is, the small vessel itself or abnormal glucose tolerance, in patients trea ted with coronary angioplasty. Background Patients with coronary artery disease with diabetes mellitus oft en show diffuse and small cornary artery narrowing. Impaired glucose tolera nce has also been reported to be a risk factor for cardiovascular disease. Methods Among 584 patients who underwent first elective balloon coronary an gioplasty, diabetes mellitus and impaired glucose tolerance were present in 197 patients. Large and small vessels were defined by reference vessel dia meter before coronary angioplasty as either larger or smaller than 2.5 mm. Patients were categorized into the following four groups: 175 patients with normal glucose tolerance and reference diameter <25 mm (group SN), 212 pat ients with normal glucose tolerance and reference diameter <greater than or equal to>2.5 mm (group LN), 101 patients with abnormal glucose tolerance a nd reference diameter <2.5mm (group SD), and 96 patients with abnormal gluc ose tolerance and reference diameter <greater than or equal to>2.5 mm (Grou p LD). The cardiac events were compared for a period of 8 years after coron ary angioplasty among the four groups. Results There was no difference in the percentage diameter stenosis immedia tely after coronary angioplasty among the four groups. However, group SD sh owed unfavourable prognosis despite similar minimal lumen diameter after co ronary angioplasty compared with group SN. Event-free survival curve of gro up LD showed a sudden drop approximately 5 years after the coronary angiopl asty. In multivariate analysis, the cardiac events were associated with the presence or absence of abnormal glucose tolerance. Furthermore, patients w ith bad glycaemic control (HbA1c>6.0%) at index coronary angioplasty showed worse event free survival than those with good glycaemic control. Conclusions An important determinant for long-term prognosis after coronary angioplasty is a presence of abnormal glucose tolerance per sc and not sma ll vessel diameter. (Eur Heart J 2000; 21: 1790-1796, doi.10.1053/euhj. 200 0.2181) (C) 2000 The European Society of Cardiology.