Growth Differentiation Factor-15 Correlates Inversely with Protease-Activated Receptor-1-Mediated Platelet Reactivity in Patients with Left Ventricular Assist Devices

Cellular and Molecular Mechanisms Activated by a Left Ventricular Assist Device

Left ventricular assist devices (LVADs) represent the final treatment for patients with end-stage heart failure (HF) not eligible for transplantation. Although LVAD design has been further improved in the last decade, their use is associated with different complications. Specifically, inflammation, fibrosis, bleeding events, right ventricular failure, and aortic valve regurgitation may occur. In addition, reverse remodeling is associated with substantial cellular and molecular changes of the failing myocardium during LVAD support with positive effects on patients' health. All these processes also lead to the identification of biomarkers identifying LVAD patients as having an augmented risk of developing associated adverse events, thus highlighting the possibility of identifying new therapeutic targets. Additionally, it has been reported that LVAD complications could cause or exacerbate a state of malnutrition, suggesting that, with an adjustment in nutrition, the general health of these patients could be improved.

Growth Differentiation Factor-15 and Clinical Outcomes in Japanese Patients With Ischemic Heart Disease

Background

Despite a reduction in the rate of thrombotic events, ischemic heart disease (IHD) remains a key medical problem associated with high major bleeding and mortality in Asian patients with IHD. Growth differentiation factor (GDF)-15, a stress-response cytokine belonging to the transforming growth factor beta superfamily, is reportedly associated with poor clinical outcomes in Western patients with IHD. However, the clinical significance of GDF-15 in Asian patients with IHD has not yet been fully elucidated.

Objectives

The aim of the present study was to examine the impact of serum GDF-15 on clinical outcomes in Japanese patients with IHD.

Methods

Serum GDF-15 levels were evaluated in 632 consecutive patients with IHD. All patients were followed up for a median period of 2.8 years. The primary endpoint was the all-cause mortality rate. Secondary endpoints were major adverse cardiovascular events (MACE), heart failure (HF)-related rehospitalization, bleeding, and thrombotic events.

Results

Serum GDF-15 levels were elevated in acute coronary syndrome, severe coronary artery disease, and the major Japanese version of the high bleeding risk criteria. Multivariate Cox proportional hazards regression analysis demonstrated that GDF-15 was an independent predictor of all-cause mortality, MACE, HF-related rehospitalizations, and bleeding events after adjusting for confounding risk factors but not for thrombotic events. Adding GDF-15 to risk factors significantly improved the net reclassification index and integrated discrimination improvement for all-cause deaths, MACE, HF-related rehospitalization, and bleeding events.

Conclusions

Serum GDF-15 could be a feasible marker for major bleeding and adverse clinical outcomes in Japanese patients with IHD.

Impact of ABO Blood Group on Thromboembolic and Bleeding Complications in Patients with Left Ventricular Assist Devices

BACKGROUND

 The ABO blood group system is linked to hemostasis via its relationship with von Willebrand factor (VWF) and factor VIII (FVIII). In the current study, we investigated the association of the ABO system with clinical outcomes as well as VWF and platelet function in patients with left ventricular assist devices (LVADs).

METHODS

 Bleeding and thromboembolic complications were assessed in 111 patients during 1 year after LVAD implantation. In 67 LVAD patients, VWF antigen, VWF activity, VWF ristocetin cofactor, VWF collagen-binding, and FVIII activity were assessed. Platelet surface P-selectin and activated glycoprotein IIb/IIIa were determined by flow cytometry, and soluble P-selectin was measured with an enzyme-linked immunoassay. Platelet aggregation was assessed by light transmission and impedance aggregometry.

RESULTS

 Thirty-six patients (32.4%) experienced a bleeding and 22 patients (19.8%) a thromboembolic event. In univariate analyses, patients with blood group O had numerically more bleeding complications and less thromboembolic events as compared to patients with blood group non-O (both p ≥ 0.05). After multivariable adjustment, blood group O was significantly associated with a higher risk of bleeding (hazard ratio 2.42 [95% confidence interval 1.03-5.70], p = 0.044) but not linked to thromboembolic complications.

CONCLUSION

 Patients with blood group O had significantly lower levels of VWF and FVIII (all p < 0.05), whereas P-selectin expression in response to thrombin-receptor activating peptide and soluble P-selectin were higher as compared to patients with blood group non-O (both p < 0.05). LVAD patients with blood group O are at an increased bleeding risk, potentially due to lower VWF and FVIII levels.

Growth Differentiation Factor 15 Is Associated with Platelet Reactivity in Patients with Acute Coronary Syndrome

Bleeding events in patients with acute coronary syndrome (ACS) are a risk factor for adverse outcomes, including mortality. We investigated the association of growth differentiation factor (GDF)-15, an established predictor of bleeding complications, with on-treatment platelet reactivity in ACS patients undergoing coronary stenting receiving prasugrel or ticagrelor. Platelet aggregation was measured by multiple electrode aggregometry (MEA) in response to adenosine diphosphate (ADP), arachidonic acid (AA), thrombin receptor-activating peptide (TRAP, a protease-activated receptor-1 (PAR-1) agonist), AYPGKF (a PAR-4 agonist) and collagen (COL). GDF-15 levels were measured using a commercially available assay. GDF-15 correlated inversely with MEA ADP (r = -0.202, p = 0.004), MEA AA (r = -0.139, p = 0.048) and MEA TRAP (r = -0.190, p = 0.007). After adjustment, GDF-15 was significantly associated with MEA TRAP (β = -0.150, p = 0.044), whereas no significant associations were detectable for the other agonists. Patients with low platelet reactivity in response to ADP had significantly higher GDF-15 levels (p = 0.005). In conclusion, GDF-15 is inversely associated with TRAP-inducible platelet aggregation in ACS patients treated with state-of-the-art antiplatelet therapy and significantly elevated in patients with low platelet reactivity in response to ADP.