Indocyanine Green Clearance Test via Pulse Dye Densitometry for Portal Hypertension Diagnosis in cACLD.

BACKGROUND AND AIMS: Performance of pulse dye densitometry (PDD)-estimated indocyanine green 15-min retention rate (ICG-R15) in the diagnosis of clinically significant portal hypertension (CSPH) has not been studied. A prospective compensated advanced chronic liver disease (cACLD) cohort was used to explore the capability of ICG-R15 in the differentiation of CSPH as referenced by hepatic venous pressure gradient (HVPG).

PATIENTS AND

METHODS

Performance of ICG-R15 alone and combined with Baveno VII algorithm for CSPH differentiation was established with a monocentric set and validated with a bicentric set of patients with HVPG assessment.

RESULTS

In the training set (n = 96), ICG-R15 ≥ 14% could identify 63.6% (28/44) CSPH with 96.2% specificity and 93.3% positive predictive value (PPV). ICG-R15 < 4% was able to exclude 40.4% (21/52) non-CSPH with 95.5% sensitivity and 91.3% negative predictive value (NPV). In the validation set (n = 106), ICG-R15 ≥ 14% could identify 63.6% (28/44) CSPH with 95.2% specificity and 90.3% PPV. ICG-R15 < 4% could exclude 41.9% (26/62) non-CSPH with 95.5% sensitivity and 92.9% NPV. Sensitivity analysis in the total set of patients (n = 202) reinforced robustness. Combined ICG-R15 ≥ 14% with LSM ≥ 25 kPa improved performance with 72.7% (64/88) sensitivity, 85.3% PPV and 90.4% specificity. Meanwhile, ICG-R15 < 4% with LSM ≤ 15 kPa plus platelet count ≥ 150 × 109/L excluded CSPH with 95.5% sensitivity and 94.5% NPV, reducing diagnosis uncertainty (grey zone) to 26.7%.

CONCLUSION

PDD-estimated ICG-R15 ≥ 14% could identify CSPH and ICG-R15 < 4% to exclude CSPH in cACLD patients. ICG-R15 sequential with Baveno VII enhanced diagnostic capability, warranting multicentre validation.

TRIAL REGISTRATION: NCT04123509, NCT04820166 and NCT05251272.