Background: Glucometabolic status (GS) in patients with acute myocardial infarction (AMI) has an impact on prognosis, but it may change over time.

Aim: To evaluate the prognosis after AMI treated invasively with respect to changes in GS assessed by oral glucose tolerance test at discharge and at mid-term follow-up visit (FU-visit).

Methods: Glucometabolic status was assessed by two-hour post-load glycaemia and defined as abnormal glucose tolerance (AGT) or normal glucose tolerance (NGT). Out of 454 in-hospital AMI survivors, 368 (81%) patients completed an FU-visit and were divided into four groups with respect to GS at discharge and FU-visit: group 1 — AGT at discharge and FU-visit (n = 101); group 2 — AGT at discharge and NGT at FU-visit (n = 48); group 3 — NGT at discharge and AGT at FU-visit (n = 114); and group 4 — NGT at discharge and FU-visit (n = 105). All-cause mortality was compared between groups with log-rank test.

Results: Median time from AMI to FU-visit was seven months. Median remote follow-up duration after AMI was 31 months. Two-hour post load glycaemia was significantly higher in patients with confirmed AGT at FU-visit than in other groups. Mortality was higher in group 1 (11.9%) than in group 2 (2.1%; p = 0.034) and group 4 (2.9%; p = 0.009). Mortality rates between group 2 and 4 were similar (2.1% vs. 2.9%; p = 0.781). There was no significant difference in mortality between group 1 and group 3 (11.9% vs. 6.1%; p = 0.114). Mortality in group 3 was over two-fold higher than in group 4; however, this difference was statistically non-significant (6.1% vs. 2.9%; p = 0.247).

Conclusions: Prognosis for patients with confirmed AGT was unfavourable; however, patients with AGT at discharge, in whom GS improved, had similar mortality to subjects with persistent NGT. The major clinical implication from this study is the finding that reassessment of GS by repeated oral glucose tolerance test has significant prognostic value and makes initial risk stratification performed at discharge more reliable.