Post-challenge hyperglycaemia is strongly associated with future macrovascular events and total mortality in angiographied coronary patients

The prevalence of post-challenge hyperglycaemia in coronary patients is high. Until now, it is unclear whether post-challenge hyperglycaemia is associated with an increased risk for future macrovascular events in this clinically important patient population. We enrolled 1040 patients undergoing coronary angiography for the evaluation of suspected or established coronary artery disease. In patients without previously established diabetes mellitus, an oral glucose tolerance test (oGTT) was performed. Prospectively, mortality and macrovascular events were recorded over a mean follow-up period of 3.8 years. From our patients, 394 had normal glucose tolerance (NGT), 280 post-challenge hyperglycaemia (this subgroup includes both impaired glucose tolerance and post-challenge diabetes) and 366 had conventional diabetes. The incidence of macrovascular events was significantly higher in patients with post-challenge hyperglycaemia as well as in patients with conventional diabetes than in subjects with NGT (23.6 and 29.5% vs. 18.5%; P = 0.013 and P < 0.001, respectively). Adjusted hazard ratios were 1.46 (95% CI 1.03-2.07, P = 0.033) for patients with post-challenge hyperglycaemia and 1.73 (1.25-2.37, P = 0.001) for patients with conventional diabetes. Post-challenge hyperglycaemia is associated with future macrovascular events in patients undergoing coronary angiography for the evaluation of stable coronary artery disease (CAD). Oral glucose tolerance tests in this high-risk population thus identify patients with a particularly unfavourable prognosis.