<prompt> A 56-year-old man presents with a 2-week history of fatigue. The patients past medical history is significant for aoic and mitral valve replacement 5 months ago. A CBC shows moderate anemia with an increased reticulocyte count. Which of the following best explains the pathogenesis of anemia in this patient?Complement-mediated hemolysisDecreased blood flowDirect red cell traumaSludging of erythrocytes  <response>: - Features given in the question point towards Macroangiopathic hemolytic anemia; most commonly results from direct red cell trauma dt abnormal vascular surface e.g., prosthetic hea valve - Red cell fragmentation syndromes: Disorders in which erythrocytes are subjected to mechanical disruption as they circulate in the blood intravascular hemolysis. Classified as macroangiopathic large vessels, as in this case; microangiopathic capillaries, according to site of hemolysis. Caused dt alteration of endothelial surface of blood vessels or disturbances in blood flow patterns resulting in turbulence increased shear stress. 