The prognostic impact of renal function decline during hospitalization for myocardial infarction.

We analyzed the mortality risk of myocardial infarction (MI) patients according to renal function, observed during hospitalization. Patients hospitalized for MI between 2006 and 2018 were followed (n = 5659). We divided the sample into four groups by estimated glomerular filtration (eGFR) [ml/min]: normal functions (lowest eGFR during hospitalization >60); transiently moderate insufficiency (lowest eGFR >30 and ≤60, highest >60); permanently moderate insufficiency (highest eGFR >30 and ≤60); severe insufficiency (highest and lowest eGFR ≤30). Permanently moderate renal insufficiency indicates increased 5-years all-cause mortality (hazard risk ratio: 2.27 [95% CIs: 1.87-2.75], p < 0.0001), but a similar risk was found in patients with the only transient decline of renal functions (hazard risk ratio: 2.08 [95% CIs: 1.70-2.55], p < 0.0001). Both moderate insufficiency subgroups (transient/permanent) did not statistically differ regarding mortality risk. Even just fluctuation of eGFR toward moderate insufficiency during hospitalization represents an important prognostic indicator in MI patients.