Microalbuminuria in non-diabetic STEMI: an independent predictor for acute kidney injury.

AIMS: To assess the impact of microalbuminuria on the development of acute kidney injury and to investigate its prognostic role at long term follow-up in 526 consecutive patients with ST elevation myocardial infarction without previously known diabetes.

METHODS

Microalbuminuria was measured using immunonephelemetry in the urine collected in the night.

RESULTS

Patients with microalbuminuria were older (p = 0.013). They showed higher values of peak glycemia (p = 0.017), peak Tn I (p < 0.001), NT-pro BNP (p = 0.020), ESR (p = 0.003), CRP (p = 0.020), and leukocyte count (p < 0.001). Lower eGFR was observed in patients with microalbuminuria both on admission and during ICCU stay (p = 0.048 and p = 0.003, respectively). A positive correlation was observed between CRP and microalbuminuria (Spearman's rho 0.114, p = 0.024). The composite end point was observed in 73 patients (18 patients died and 59 patients developed acute kidney injury). At multivariable regression analysis, microalbuminuria was an independent predictor of acute kidney injury. At follow-up [42.6 (25th-75th percentile, 17.5-56.8) months], Kaplan-Meier curve analysis showed that patients with microalbuminuria had a lower survival rate in respect to patients without microalbuminuria. Cox regression analysis documented that microalbuminuria was an independent predictor of long term mortality (HR: 1.089; 97% CI 1.036-1.145; p < 0.001).

CONCLUSIONS

In a large series of STEMI patients without previously known diabetes submitted to PCI, microalbuminuria, as a marker of endothelial permeability following higher systemic inflammatory activation and larger infarct lesions, is an independent predictor for the development acute kidney injury. Furthermore, microalbuminuria identifies a subset of patients at higher risk for long term mortality.