“…Studies have demonstrated a correlation between spontaneous platelet activation and LV hypertrophy in humans,10, 11 and increased P‐selectin expression has been documented in association both with congestive heart failure and HCM in humans 12, 13, 14. When considering the association of heart disease and platelet activation, an enlarged left atrium, endothelial damage, and the presence of mitral regurgitation all have the potential to generate high shear, resulting in platelet up‐regulation, release of alpha granule components, and increased sensitivity to agonists 15, 16. In vitro studies by Holme et al17 demonstrated shear‐induced platelet activation and development of platelet microparticles under flow conditions that may be similar to those associated with diastolic dysfunction in cats with HCM as suggested by Bedard et al 18…”