Background. In patients with myocardial infarction ( MI ), reduced kidney function is recognized as an important predictor of poor prognosis, but the impact of albuminuria, a representative measure of kidney damage, has not been extensively evaluated.
Methods and Results. In the SCREAM (Stockholm Creatinine Measurements) project (2006-2012), we identified 2469 patients with incident MI with dipstick proteinuria measured within a year before MI (427 patients also had urine albumin to creatinine ratio [ ACR ] measured concurrently) and obtained estimates for ACR with multiple imputation in participants with data solely on dipstick proteinuria. We quantified the association of ACR with the post- MI composite and individual outcomes of all-cause mortality, cardiovascular mortality, recurrent MI , ischemic stroke, or heart failure using Cox models and then evaluated the improvement in C statistic. During a median follow-up of 1.0 year after MI , 1607 participants (65.1%) developed the post- MI composite outcome. Higher ACR levels were independently associated with all outcomes except for ischemic stroke. Per 8-fold higher ACR (eg, 40 versus 5 mg/g), the hazard ratio of composite outcome was 1.21 (95% CI , 1.08-1.35). The addition of the ACR improved the C statistic of the post- MI composite by 0.040 (95% CI, 0.030-0.051). Largely similar results were obtained regardless of diabetic status and when ACR or dipstick was separately analyzed without imputation.
Conclusions. In patients with MI , albuminuria was a potent predictor of subsequent outcomes, suggesting the importance of paying attention to the information on albuminuria, in addition to kidney function, in this high-risk population.