Kidney disease (KD) in patients with acute myocardial infarction (AMI) is associated with major cardiovascular events (MACE). We sought to compare the long-term variation in KD in patients with AMI versus controls and its value as a risk factor for MACE in patients with AMI. A cohort of 300 outpatients with AMI, recruited between 2014 and 2016 in Barcelona, Spain, were compared with a control cohort matched 1:1 based on age and several risk factors for developing KD. Annual estimated glomerular filtration rate (eGFR) using MDRD-4 formula and albuminuria were collected and patients were followed up for the occurrence of MACE (death, heart failure hospitalization, AMI, or stroke). After a median follow-up of 5.3 years, the decline in eGFR was more pronounced in patients with AMI (−1.15 ml/min/1.73 m2/ per year in patients with AMI vs −0.81 ml/min/1.73 m2 per year in controls, p = 0.018 between the ß coefficients of both regression slopes). In patients with AMI, those with the greatest eGFR decline during follow-up had more MACE (hazard ratio [HR] for first vs fourth quartiles = 3.33, p <0.001). In multivariate analysis, after excluding patients with baseline KD, a newly diagnosed eGFR <60 ml/min/1.73 m2 during follow-up was associated with MACE (HR = 3.21, p <0.001), as well as new onset albuminuria >30 mg/g (HR = 6.93, p <0.001) and the combination of both (HR 5.63, p <0.001). In conclusion, the decline in eGFR after AMI is more pronounced than in the general population. A longitudinal drop in eGFR and newly diagnosed albuminuria during follow-up are associated with MACE and can be useful tools to reclassify the risk profile after AMI
