Importance of stratifying acute kidney injury in cardiogenic shock resuscitated with mechanical circulatory support therapy.

OBJECTIVE: Although the outcomes of patients with cardiogenic shock remain poor, short-term mechanical circulatory support has become an increasingly popular modality for hemodynamic assistance and organ preservation. Because the kidney is exquisitely sensitive to poor perfusion, acute kidney injury is a common sequela of cardiogenic shock. This study examines the incidence and clinical impact of acute kidney injury in patients with short-term mechanical circulatory support for cardiogenic shock.

METHODS: Retrospective review was performed of 293 consecutive patients with cardiogenic shock who were treated with short-term mechanical circulatory support. The well-validated 2014 Kidney Disease Improving Global Outcomes criteria were used to stage acute kidney injury. Outcomes of interest were long-term mortality and renal recovery.

RESULTS: Acute kidney injury developed in 177 of 293 patients (60.4%), of whom 113 (38.6%) were classified with stage 3 (severe). Kaplan-Meier survival estimates indicated a 1-year survival of 49.2% in the nonsevere (stages 0-2) acute kidney injury cohort versus 27.3% in the severe acute kidney injury cohort (P < .001). Multivariable Cox regression demonstrated that severe acute kidney injury was a predictor of long-term mortality (hazard ratio, 1.54; confidence interval, 1.10-2.14; P = .011). Among hospital survivors, renal recovery occurred more frequently (82.4% vs 63.2%, P = .069) and more quickly (5.6 vs 24.5 days, P < .0001) in the nonsevere than in the severe acute kidney injury group.

CONCLUSIONS: Acute kidney injury is common and frequently severe in patients in cardiogenic shock treated with short-term mechanical circulatory support. Milder acute kidney injury resolves with survival comparable to patients without acute kidney injury. Severe acute kidney injury is an independent predictor of long-term mortality. Nonetheless, many surviving patients with acute kidney injury do experience gradual renal recovery.