Echocardiographic correlates of acute kidney injury in cardiac intensive care unit patients.

BACKGROUND

Acute kidney injury (AKI) is prevalent in the cardiac intensive care unit (CICU) population. We evaluated the association between transthoracic echocardiogram (TTE)-derived hemodynamics and AKI among CICU patients.

METHODS

We included adults admitted to an academic CICU from 2007 to 2018 who had a consultative TTE within 24 h. De novo AKI was defined by modified Kidney Disease: Improving Global Outcomes criteria using serum creatinine. Pressure-adjusted heart rate (PAHR), in beats per minute (BPM), was defined as (right atrial pressure ÷ mean arterial pressure) × heart rate. The primary outcome was the association between TTE hemodynamics and AKI incidence, and the secondary outcome was the association between AKI and mortality.

RESULTS

Among 7027 patients, AKI occurred in 2157 (30.7%), of whom 585 (8.3%) had moderate/severe AKI. More severe AKI was associated with worse left ventricular, right ventricular (RV), and biventricular function (all P < 0.001). TTE markers of RV function demonstrated greater discrimination for moderate/severe AKI compared to left-sided indices. Among TTE variables, PAHR ≥7.5 BPM provided the highest discrimination and identified a higher-risk hemodynamic phenotype for moderate/severe AKI (13.1% for PAHR ≥7.5 BPM vs. 3.8% for PAHR <7.5 BPM, P < 0.001). More severe AKI was associated with higher in-hospital and one-year mortality (both P < 0.001).

CONCLUSIONS

Among CICU patients, moderate/severe AKI was associated with biventricular systolic dysfunction and congestion as assessed by TTE. PAHR demonstrated the greatest discrimination among TTE variables and identified a higher-risk hemodynamic phenotype for moderate/severe AKI. TTE measurements may facilitate early identification of patients at risk of AKI.