Intrarenal Doppler Ultrasound Renal Venous Stasis Index Correlates With Acute Cardiorenal Syndrome in Patients With Acute Decompensated Heart Failure

BACKGROUND: Acute cardiorenal syndrome (ACRS) is associated with adverse outcomes in patients with acute decompensated heart failure (ADHF). Intrarenal venous blood flow can be assessed using Doppler ultrasound and has prognostic significance in ADHF. Although intrarenal Doppler (IRD) may be sensitive to renal congestion, an association between IRD parameters and ACRS has not been demonstrated in an ADHF population. METHODS: Hospitalized patients with ADHF (n = 21) or acute coronary syndrome (ACS; n = 21) were prospectively enrolled. Patients underwent echocardiography, including IRD, using a standard cardiac ultrasound transducer. Intrarenal venous flow was quantified with the renal venous stasis index (RVSI), defined as the duration of absent venous flow time divided by cardiac cycle duration. The primary outcome was acute kidney injury (AKI) as assessed using the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. RESULTS: ADHF patients had a similar cardiac index (2.0 ± 0.6 vs 2.1 ± 0.4 L/min per m(2), P = 0.91) but higher estimated central venous pressure (13.0 ± 3.2 vs 4.6 ± 2.4 mm Hg, P < 0.001) measured using echocardiography, compared with ACS patients. IRD was abnormal in all ADHF patients and normal in all ACS patients (RVSI 0.62 ± 0.20 vs 0.0 ± 0, P < 0.001). AKI stage II/III occurred in 10 of 21 ADHF patients (48%) vs 0 of 21 ACS patients (P < 0.001), with a mean rise in serum creatinine of 97.7 ± 79.3 vs 16.8 ± 10.9 μmol/L (P < 0.001), respectively. RVSI was correlated with AKI severity in ADHF patients (r = 0.57; P = 0.004). CONCLUSIONS: RVSI is associated with AKI among ADHF patients and may be a useful diagnostic biomarker for ACRS in this setting. Further studies are needed to validate this finding and evaluate the potential efficacy of IRD-guided decongestive therapy in this setting.