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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, METHODS, RESULTS. Meshes: Analysis of Variance, Blood Flow Velocity, Blood Platelet Disorders, Cardiac Surgical Procedures, Cardiopulmonary Bypass, Child, Child, Preschool, Cohort Studies, Confidence Intervals, Echocardiography, Doppler, Female, Follow-Up Studies, Heart Defects, Congenital, Humans, Infant, Infant, Newborn, Kaplan-Meier Estimate, Male, Platelet Function Tests, Predictive Value of Tests, Preoperative Period, Retrospective Studies, Risk Assessment, Survival Analysis, Treatment Outcome.
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Does high flow velocity through congenital cardiac lesions predict preoperative platelet dysfunction? Context: Platelet dysfunction resulting from abnormal fluid shear stress has been reported in adults with aortic stenosis. Blood flowing through a congenital heart defect at greater than normal velocity is subjected to increased shear stress. The primary aim was to determine whether peak flow velocity through congenital cardiac lesions predicts preoperative platelet dysfunction. The charts of 402 patients who underwent cardiopulmonary bypass and had preoperative platelet function analysis were evaluated. Platelet dysfunction was measured as a prolonged closure time (CT) in seconds with a platelet function analyzer. Echocardiography was used to determine peak velocity. The relationship between peak velocity and CT was analyzed using linear regression and Kaplan-Meier estimation. The distribution of peak velocity was bimodal. The mean velocity of the lower group was 1.9 m/second and the higher group was 4.2 m/second. Univariate analysis showed age, weight, peak velocity, hematocrit, and Risk Adjustment for Congenital Heart Surgery score to be associated with prolonged CT. Using multivariable analysis, prolonged CT was significantly associated with peak velocity (p < 0.001). For each 1m/second increase in peak velocity the CT increased by over 9 seconds (p < 0.001). In addition, a median CT increase of more than 6 seconds was also associated with a 5 percentage point drop in hematocrit (p = 0.04).
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Platelet dysfunction is associated with high blood flow velocity through congenital cardiac lesions. Lower preoperative hematocrit was associated with prolonged CT, which may suggest subclinical bleeding secondary to platelet dysfunction. Final Decision: yes