Introduction:

The risk of lactat acidosis in patients taking metformin is well known but seems overrated as serveral data the last years have shown. It is uncertain if patients with ST segment elevation myocardial infarction (STEMI) undergoing coronary angiography and taking metformin are at higher risk for renal failure, in-hospital mortality and longer in-hospital-stay.

Methods:

A retrospective analysis of 10.165 patients from the monocentric Bremen STEMI-Registry (BSR) was performed comparing patients without diabetes mellitus type 2, those with metformin-therapy and those with insulin-therapy. All patients underwent coronary angiography for STEMI. Differences in baseline-characteristics, acute renal failure, in-hospital-mortality and length of in-hospital-stay were examined. 

Results:

Patients with diabetes mellitus were older and more often received bypass-surgery (Table 1). They had higher creatinine-levels ad admission, but patients taking metformin were not at higher risk for acute renal failure (4,3% vs. 5,6%; p = 0,1) or in-hospital-death (7,9% vs. 9,4%; p = 0,08). 

Cardiogenic shock was less common in the metformin-group and creatinkinase-levels were significantly lower. The amount of contrast media was similar in the metformin-group compared to patients without diabetes. Patients with insulin-dependent diabetes more often presented in cardiogenic shock, had highest creatinine-levels ad admission, higher amount of contrast media, more often acute renal failure and a significantly higher risk for in-hospital death than the metformin-group. In-hospital-stay was slightly longer in patients receiving metformin (6,8±7 vs. 7,5±7,5 days; p < 0,01).

Conclusion:

“Real world”-Data show no significantly elevated risk for acute renal failure or in-hospital-death as surrogate parameters of severe lactat acidosis in patients taking metformin and undergoing coronary angiography for STEMI. Insulin-dependent diabetics with STEMI however represent a critically ill cohort at high risk for acute renal failure and in-hospital death, which need special clinical attention.

Table 1: