The impact of preinfarct angina on the incidence of acute kidney injury in patients with myocardial infarction: interaction with pre-existent chronic kidney disease.

AIM: Remote ischemic conditioning may reduce acute kidney injury (AKI) in patients undergoing a coronary intervention. As preinfarct angina (PIA) might act as a preconditioning stimulus in patients with ST-elevation myocardial infarction (STEMI), we aimed to study whether PIA reduces AKI in accordance to pre-existing chronic kidney disease.

PATIENTS AND METHODS: We conducted a retrospective study including 891 consecutive STEMI patients who underwent primary coronary intervention from January 2008 to March 2016. AKI was determined on the basis of KDIGO criteria. The impact of PIA was evaluated in three groups according to the baseline glomerular filtration rate: less than 45 ml/min/1.73 m (group 1, n=89), 45-59 ml/min/1.73 m (group 2, n=117), and greater than or equal to 60 ml/min/1.73 m (group 3, n=642). Univariate and multivariate predictors for AKI were determined.

RESULTS: AKI developed in 13.8% of patients (n=117) and was more prevalent in patients with worse baseline renal function (35% in group 1; 22% in group 2; and 9% in group 3, P<0.01). The prevalence of PIA was similar across groups (28-34%, P=0.2). Only in group 1 did patients with PIA have a significantly lower rate of AKI than patients without PIA (19 vs. 42%, P=0.033). In multivariate analysis, the absence of PIA in group 1 patients conferred an almost three-fold risk of developing AKI (odds ratio=2.92, P=0.009), whereas no differences were found for the other groups. Age, total ischemic time, and intra-aortic balloon pump utilization were also related independently to AKI.

CONCLUSION: In our series, STEMI patients with at least stage 3B chronic kidney disease had a three-fold risk of developing AKI in the absence of PIA. These findings suggest that patients with worse renal function may be more susceptible to the renoprotective effect of myocardial ischemic preconditioning.