Increased intracellular calcium and decreased deformability of erythrocytes from prosthetic heart valve patients

The erythrocytes from twenty prosthetic cardiac valve recipients were studied for cellular deform ability (P₀) and levels of intracellular calcium. Deformability was measured by a filtration method and calcium content was determined by atomic absorption spectroscopy. Erythrocyte rigidity and levels of calcium were significantly increased compared to control subjects (p < 0.01). Prosthetic valve patients were divided into two groups on the basis of clinically significant hemolysis (cellular morphology and values of hematocrit and serum lactate dehydrogenase). Valve recipients with evidence of significant hemolysis had more rigid erythrocytes and higher intracellular calcium levels than patients without signs of extensive erythrocyte destruction. The deformability indicator P₀ correlated closely with values of the patients’ serum lactate dehydrogenase (p < 0.01), hematocrit (p < 0.00l) and erythrocyte intracellular calcium (p < 0.001). These data suggest a causal role for loss of cellular deformability and increased intracellular calcium in the shortened erythrocyte life span in patients with prosthetic cardiac valves.