Background: A subgroup of patients with acute kidney injury (AKI) do not fulfil the functional criteria for AKI diagnosis but show elevated levels of new biomarkers reflecting tubular injury, suggesting that these patients suffer “subclinical AKI”. We investigated the incidence and possible implications of “subclinical AKI”, compared to no and clinical AKI among ST elevation myocardial infarction patients (STEMI) treated with primary coronary intervention (PCI). Methods: We included 223 patients with STEMI treated with PCI. Neutrophil gelatinase-associated lipocalin (NGAL) was used as a marker of renal tubular damage in the absence of functional AKI, with NGAL levels ≥100 ng/mL suggesting subclinical AKI. Patients were assessed for the occurrence of in-hospital adverse outcomes. Results: Of the study patients, 45 (25%) had subclinical AKI. These patients were more likely to have left ventricular ejection fraction ≤45% (33% vs. 23%. p = 0.01), in-hospital adverse outcomes (73% vs. 48%; p = 0.005), and a combination of the two. The multivariate regression model demonstrated that subclinical AKI was independently associated with in-hospital adverse outcomes (OR 3.71, 95% CI 1.30–10.62, p = 0.02). Conclusions: Subclinical AKI is common among STEMI patients and is independently associated with adverse outcomes, even in the absence of functional AKI.

Background: The risk of contrast-induced acute kidney injury (CI-AKI) following coronary intervention is particularly high among patients with chronic kidney disease (CKD). Among these patients, baseline neutrophil gelatinase-associated lipocalin (NGAL), a marker of tubular damage, reflects the severity of renal impairment. We evaluated whether the baseline serum NGAL level may be a marker for the development of CI-AKI following percutaneous coronary intervention (PCI). Methods: Eighty-eight CKD patients treated with PCI were included. Serum NGAL levels were drawn upon hospital admission. Receiver operator characteristic (ROC) methods were used to identify the optimal sensitivity and specificity for the observed NGAL level compared with the estimated glomerular filtration rate (eGFR) calculated for patients with CI-AKI. Results: Overall CI-AKI incidence was 43%. Baseline serum NGAL levels were significantly higher in patients with CI-AKI than in patients without CI-AKI (150 vs. 103 ng/mL, p < 0.001). According to the ROC curve, baseline NGAL levels performed better than eGFR to predict CI-AKI (AUC 0.753 vs. 0.604), with the optimal cutoff value for baseline NGAL to predict CI-AKI being 127 ng/mL (sensitivity of 68% and specificity of 68%, p < 0.001). In a multivariate logistic regression model, the NGAL level >127 ng/mL ng/mL was independently associated with CI-AKI (HR 9.84, 95% CI: 1.96–40.3; p = 0.01). Conclusion: Baseline serum NGAL levels in CKD patients may identify a high-risk population for CI-AKI following PCI. Further studies on larger populations are required to validate the potential utility of NGAL measurements in monitoring specific CKD-associated conditions.

Background: Among patients with rhabdomyolysis, the leakage of intracellular skeletal muscle content such as creatine phosphokinase (CPK) into the bloodstream has been associated with an increased risk of acute kidney injury (AKI). We evaluated the possible relationship between serum CPK levels and AKI occurrence among patients with myocyte injury secondary to ST-elevation myocardial infarction (STEMI). Methods: We retrospectively included 2794 patients with STEMI. Patients were stratified according to peak serum CPK levels into mild (5000 U/L, n = 80) categories. The occurrence of AKI was defined by the KDIGO criteria as an increase in serum creatinine (sCR) ≥0.3 mg/dL within 48 h following PCI. The predictive value of CPK for the risk of AKI occurrence was assessed using multivariate logistic regression models. Results: The overall occurrence of AKI was 10.4%. Incidence of AKI showed a gradual increase between patients with mild, moderate, and severe serum CPK level elevations (7.8% vs. 11% vs. 26% respectively; p < 0.001). In multivariate logistic regression models, both moderate or higher (OR 1.6, 95% CI 1.1–2.2; p = 0.01) and severe (OR 2.8 95% CI 1.4–5.6; p = 0.004) serum CPK level elevations were independently associated with AKI. Conclusions: Among STEMI patients, elevated CPK levels were associated with AKI. This association is presumably independent; however, it remains unclear whether it is due to direct toxic (myoglobin-related) or hemodynamic effects (poor left ventricular function). Further studies are required to reveal the underlying mechanism.

Background: Primary percutaneous coronary intervention (PCI) is the preferred treatment strategy for patients with ST-elevation myocardial infarction (STEMI); however, its efficacy remains unclear in very older adult patients with STEMI.Methods: This retrospective single-center observational study included 530 patients aged >75 years admitted to Tel Aviv Sourasky Medical Center with a diagnosis of acute STEMI. Primary PCI was performed for patients with symptoms ≤12 hours in duration, while the other patients were conservatively treated. We evaluated 30-day mortality and complications occurring during hospitalization based on data from patient records.Results: Among the study patients, only 28/530 (5%) were conservatively treated. In-hospital complications, including the use of inotropes or intra-aortic balloon counterpulsation and the need for mechanical ventilation, did not differ significantly between the groups. The only parameter that showed a trend toward significance was the incidence of heart failure during hospitalization (p=0.042). The risk for 30-day mortality was substantially higher in the conservative treatment group than in the invasive treatment group (27% vs. 10%; p = 0.02).Conclusion: Our data suggested that despite concerns regarding the safety of the primary PCI strategy in the older adult STEMI population, this treatment strategy was associated with a survival benefit.