Circulating Kidney Injury Molecule-1 Levels in Acute Heart Failure: Insights From the ASCEND-HF Trial (Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure).

OBJECTIVES This study sought to determine the relationship of KIM-1 levels with adverse clinical outcomes in acute decompensated heart failure (ADHF). BACKGROUND Kidney injury molecule (KIM)-1 is a biomarker expressed by the nephron in acute tubular injury, and is a sensitive and specific marker for early acute kidney injury. Although commonly measured in urine, KIM-1 levels are also detectable in plasma, but its clinical and prognostic utility in ADHF is unknown. METHODS Baseline, 48- to 72-h, and 30-day KIM-1 plasma levels were measured in 874 subjects in the ASCEND-HF (Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure) trial. Multivariable logistic and Cox models were used to assess the relationship between KIM-1 levels and outcomes during and after ADHF. RESULTS The median circulating KIM-1 level at baseline was 375.4 pg/ml (interquartile range [IQR]: 237.0 to 633.1 pg/ml), at 48 to 72 h was 373.7 pg/ml (IQR: 220.3 to 640.5 pg/ml), and at 30 days was 382.6 pg/ml (IQR: 236.5 to 638.0 pg/ml). There were no associations between KIM-1 levels and any 30-day outcomes. In univariable analysis, both baseline and follow-up KIM-1 were associated with greater 180-day mortality risk. However, after adjusting for blood urea nitrogen or creatinine in addition to established risk predictors from ASCEND-HF, higher KIM-1 at all time points during hospitalization was not associated with in-hospital or post-discharge outcomes (all p > 0.05), but KIM-1 levels measured at 30 days were associated independently with 180-day mortality (hazard ratio: 1.49; p = 0.04). CONCLUSIONS In our study cohort, circulating KIM-1 at baseline and during hospitalization was not associated with adverse clinical outcomes in ADHF after adjusting for standard indices of kidney function.