UCLA

Background

A significant minority of patients receiving cardiac resynchronization therapy (CRT) remain nonresponsive to this intervention.

Objective

This study aimed to determine whether coronary sinus (CS) or baseline peripheral venous (PV) levels of established and emerging heart failure (HF) biomarkers are predictive of CRT outcomes.

Methods

In 73 patients (aged 68 ± 12 years; 83% men; ejection fraction 27% ± 7%) with CS and PV blood samples drawn simultaneously at the time of CRT device implantation, we measured amino-terminal pro-B-type natriuretic peptide (NT-proBNP), galectin-3 (gal-3), and soluble ST2 (sST2) levels. NT-proBNP concentrations >2000 pg/mL, gal-3 concentrations >25.9 ng/mL, and sST2 concentrations >35 ng/mL were considered positive on the basis of established PV cut points for identifying "high-risk" individuals with HF. CRT response was adjudicated by the HF Clinical Composite Score. A major adverse cardiovascular event (MACE) was defined as the composite end point of death, cardiac transplant, left ventricular assist device, and HF hospitalization at 2 years.

Results

NT-proBNP concentrations were 20% higher in the CS than in the periphery, while gal-3 and sST2 concentrations were 10% higher in the periphery than in the CS (all P < .001). There were 45% CRT nonresponders at 6 months and 16 (22%) patients with MACE. Triple-positive CS values yielded the highest specificity of 95% for predicting CRT nonresponse. Consistently, CS strategies identified patients at higher risk of developing MACE, with >11-fold adjusted increase for triple-positive CS patients compared to triple-negative patients (all P ≤ .04). PV strategies were not predictive of MACE.

Conclusion

Our findings suggest that CS sampling of HF biomarkers may be better than PV sampling for predicting CRT outcomes. Larger studies are needed to confirm our findings.