High Mortality with Acute Kidney Injury after Mechanical Support for Cardiogenic Shock

Mechanical circulatory support devices (MCSD) have been increasingly used for patients with cardiogenic shock (CS). Exquisitely sensitive to states of poor perfusion, renal injury is a common sequela of CS. This study examines the attributes of renal injury and its association with outcomes in MCS therapy for CS. In our program, patients in CS refractory to medical management are treated with a short-term MCSD, either with veno-arterial extracorporeal membrane oxygenation (ECMO) or external short-term ventricular assist device (ST-VAD). This is a retrospective review of patients treated with MCSD for CS from 2007 to 2013 at our institution. KDIGO 2014 criteria were used to stage acute kidney injury based on a comparison of creatinine within the first 7 postoperative days to a preoperative baseline. A total of 387 device runs of MCSD for CS were recorded during this period. Multiple device runs and patients with ESRD were excluded. 285 patients were eligible for analysis in this study. Etiologies of CS included postcardiotomy shock in 89 patients (31.1%), acute myocardial infarction in 78 (27.3%), acute decompensated heart failure in 48(16.8%), and graft dysfunction in 37(12.9%). Only 97 (39.4%) were free from any AKI. Twenty seven (11%) experienced Stage 1 AKI, 22(8.9%) had Stage 2 AKI, while 100 patients (40.7%) had Stage 3 AKI. In-hospital mortality between patients with non-severe renal insult (Stage 1, 2, or none) and those with severe AKI (Stage 3) was 42.3% (N=60) and 64.5% (N=60, p=.001) respectively. Survival analysis showed that 51.2% of the non-severe AKI group survived to 1-year compared to 24.6% of the Stage 3 AKI group. Multivariable logistic regression indicated that the presence of severe AKI was associated with a higher risk of in-hospital mortality (OR:2.8, CI:1.1-7.0, p=.028). AKI is very common after CS treated with MCS. Stage 3 AKI seems to be a strong predictor of in-hospital mortality with hospital discharge expected in less than 40% of patients with severe AKI.