Is kidney function affecting the management of myocardial infarction? A retrospective cohort study in patients with normal kidney function, chronic kidney disease stage III-V, and ESRD

Patients with chronic kidney disease (CKD) are three times more likely to have myocardial infarction (MI) and suffer from increased morbidity and higher mortality. Traditional and unique risk factors are prevalent and constitute challenges for the standard of care. However, CKD patients have been largely excluded from clinical trials and little evidence is available to guide evidence-based treatment of coronary artery disease in patients with CKD. Our objective was to assess whether a difference exists in the management of MI (ST-segment elevation myocardial infarction and non-ST-segment elevation myocardial infarction) among patients with normal kidney function, CKD stage III-V, and end-stage renal disease (ESRD) patients. We conducted a retrospective cohort study on patients admitted to Staten Island University Hospital for the diagnosis of MI between January 2005 and December 2012. Patients were assigned to one of three groups according to their kidney function: Data collected on the medical management and the use of statins, platelet inhibitors, beta-blockers, and angiotensin converting enzyme inhibitors/angiotensin receptor blockers were compared among the three cohorts, as well as medical interventions including: catheterization and coronary artery bypass graft (CABG) when indicated. Chi-square test was used to compare the proportions between nominal variables. Binary logistic analysis was used in order to determine associations between treatment modalities and comorbidities, and to account for possible confounding factors. Three hundred and thirty-four patients (mean age 67.2 +/- 13.9 years) were included. In terms of management, medical treatment was not different among the three groups. However, cardiac catheterization was performed less in ESRD when compared with no CKD and CKD stage III-V (45.6% vs 74% and 93.9%) (P<0.001). CABG was performed in comparable proportions in the three groups and CABG was not associated with the degree of CKD (P=0.078) in binary logistics regression. Cardiac catheterization on the other hand carried the strongest association among all studied variables (P<0.001). This association was maintained after adjusting for other comorbidities. The length of stay for the three cohorts (non-CKD, CKD stage III-V, and ESRD on hemodialysis) was 16, 17, and 15 days, respectively and was not statistically different. Many observations have reported discrimination of care for patients with CKD considered suboptimal candidates for aggressive management of their cardiac disease. In our study, medical therapy was achieved at high percentage and was comparable among groups of different kidney function. However, kidney disease seems to affect the management of patients with acute MI; percutaneous coronary angiography is not uniformly performed in patients with CKD and ESRD when compared with patients with normal kidney function.