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Platelet Aggregation Before Aspirin Initiation in Pediatric Patients With Congenital Heart Disease at High Risk of
Zhong-Yuan Lu1, Zhi-Yuan Zhu1, Ju-Xian Yang1
1Pediatric Intensive Care Unit, Pediatric Cardiac Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China.
Insights
Pediatric cardiac surgery patients often have impaired platelet aggregation before aspirin therapy. Cardiopulmonary bypass, timing, and platelet count influence this response, necessitating baseline testing post-procedure.
Area of Science:
- Pediatric Cardiology
- Hematology
- Thrombosis Research
Background:
- Aspirin and unfractionated heparin are common anticoagulants for pediatric cardiac surgery patients at high risk of thrombosis.
- Platelet aggregation testing is crucial for assessing aspirin's effect on platelet function.
- However, the basal status of platelet aggregation and its clinical influencing factors before postoperative aspirin initiation in this population remain under-investigated.
Purpose of the Study:
- To investigate the basal platelet aggregation status in pediatric patients after cardiac surgery before initiating aspirin therapy.
- To identify clinical factors influencing basal platelet aggregation in this cohort.
Main Methods:
- A prospective cohort study involving 247 children undergoing cardiac surgery.
- Measurement of arachidonic acid-induced platelet aggregation (PAG-AA) using light transmission aggregometry (LTA) before the first postoperative aspirin dose.
- Collection of perioperative variables and analysis using univariate and multivariate logistic regression.
Main Results:
- The median basal PAG-AA was 20.70%, with a significant portion of patients exhibiting impaired aggregation (67.6% < 55%, 47.8% < 20%).
- Patients who underwent cardiopulmonary bypass (CPB) showed significantly lower basal PAG-AA compared to those who did not (p=0.013).
- Lower PAG-AA was also observed within 3 days after CPB (p=0.001). CPB use, test time point, and platelet count were identified as independent influencing factors.
Conclusions:
- Most children display impaired basal platelet aggregation responses prior to postoperative aspirin initiation.
- Cardiopulmonary bypass, timing of testing, and platelet count are key determinants of basal platelet aggregation.
- Establishing a baseline platelet aggregation profile should be done at least 3 days post-procedure to account for the diminishing effects of CPB.
Background:
Aspirin following unfractionated heparin is the most common anticoagulation strategy for pediatric patients who experienced cardiac surgery at high risk of thrombosis. The platelet aggregation test is the golden method to evaluate the aspirin effect on platelet function. However, the platelet aggregation basal status before postoperative aspirin initiation and the related clinical influencing factors hasn't been investigated systemically in this population.
Methods:
In a prospective cohort of 247 children, arachidonic acid-induced platelet aggregation (PAG-AA) was measured by means of light transmission aggregometry (LTA) before the first dose of aspirin after cardiac surgical procedure and the perioperative variables were also collected. Distribution of this population's PAG-AA basal status was described. Univariate and multivariate logistic regression analysis were performed to identify the main influencing factors of PAG-AA.
Results:
The median time of aspirin administration was 2 (1-27) days after surgery and the corresponding median value of basal PAG-AA was 20.70% (1.28-86.49%), with 67.6% population under 55% and 47.8% population under 20%. Patients undergoing cardiopulmonary bypass (CPB) had a significantly lower basal PAG-AA than those without (30.63 ± 27.35 vs. 57.91 ± 27.58, p = 0.013). While patients whose test done within 3 days after CPB had a significantly lower PAG-AA than those out of 3 days (25.61 ± 25.59 vs. 48.59 ± 26.45, p = 0.001). Univariate analysis implied that the influencing factors of the basal PAG-AA including CPB use, test time point, cyanosis, and platelet count. Multivariate regression analysis indicated that only CPB use, test time point, and platelet count were the main independent influencing factors for the basal PAG-AA.
Conclusion:
The majority of children have impaired basal platelet aggregometry responses before postoperative aspirin initiation. The main influencing factors are CPB use, test time point, and platelet count. To establish the platelet aggregometry baseline prior to commencement of aspirin therapy, testing should be performed 3 days later following the procedure when effect of CPB is basically over.
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