Metformin and contrast-induced acute kidney injury in diabetic patients treated with primary percutaneous coronary intervention for ST segment elevation myocardial infarction: Amulticenter study.

AIM: To analyze the association between chronic metformin treatment and the development of contrast-induced acute kidney injury (CI-AKI) after primary percutaneous coronary intervention (PCI) for ST segment elevation myocardial infarction (STEMI).

METHODS: Patients with type 2 diabetes mellitus (T2DM) treated with PCI <24h in 2 coronary care units were included. Serum creatinine (Cr) was measured before and <48h after PCI. CI-AKI was defined as an increase in Cr>27μmol/l (0.3mg/dl) or >50% over baseline after PCI. Since PCI was urgent, metformin could not be withheld prior to PCI but was usually stopped after PCI.

RESULTS: Among the 372 patients included, 147 (40%) were using metformin, which had older diabetes, but had risk factors similar to patients without metformin. Baseline eGFR was better in patients under metformin therapy. After PCI, we observed an increase of ≈10% in Cr, for both groups. There was a trend toward a lower rate of CI-AKI in patients under metformin (16% vs 25%, p=0.051). In patients with chronic kidney disease, 31 (26%) were under metformin therapy, and the rate of CI-AKI was similar in both groups (41% vs 40%, p=0.915). By multivariate analysis, metformin showed a trend toward a reduced rate of CI-AKI, even when adjusted for confounding (OR (95% CI): 0.548 (0.276-1.087)). No case of lactic acidosis was reported during the hospital stay. Moreover, there was no increased rate of cardiogenic shock or death with metformin treatment.

CONCLUSION: In this multicenter observational study, chronic metformin treatment prior to primary PCI had no significant impact on CI-AKI.