The biomarker plasma galectin-3 in advanced heart failure and survival with mechanical circulatory support devices

Background: During screening of heart transplantation (HTx) candidates supported by ventricular assist devices (VADs) for plasma biomarkers we found that galectin-3 (Gal-3) was increased pre-operatively in patients who later died during VAD support. Therefore, we analyzed the predictive value of plasma Gal-3 in the context of other potential clinical risk factors for death on device (DOD) in a cohort of 175 VAD patients.

Methods: We analyzed numerous clinical factors and plasma Gal-3 levels of 175 VAD patients before device implantation. Eighty VAD patients were successfully bridged to HTx (BTT, 45.7%), 80 (45.7%) died on VAD, 2 recovered on device (BTR, 1.1%) and 13 (7.4%) were still on device. Uni- and multivariate analyses were performed to assess the importance of Gal-3 with respect to other clinical factors. Myocardial gene expression of Gal-3 was investigated in apex samples by RT-PCR (n = 30) and Western blotting (n = 45).

Results: Plasma Gal-3 levels were higher in VAD patients than in controls (16.6 ± 9.3 vs 9.5 ± 3.9 ng/ml, p < 0.0001). Cox regression showed several clinical factors and type of VAD as independent outcome predictors, but Gal-3 was not among them. Using the regression equation we grouped patients according to their factor constellation for prediction of survival on VAD. We propose a calculation method for VAD survival prediction. Gal-3 mRNA and protein were detectable in failing myocardium, but did not correlate with its plasma concentration.

Conclusions: Galectin-3 levels are associated with severe heart failure but do not provide sufficient discrimination for prediction of outcomes after VAD implantation. Importantly, we were unable to confirm myocardial tissue as a primary source for the observed plasma elevations of Gal-3.