Aspirin Resistance in Children with Congenital Heart Disease and Its Relationship with Laboratory and Clinical Parameters

Patients with congenital heart disease (CHD) are more prone to thromboembolism. Aspirin is the most commonly used medication around the world to prevent thrombosis in cardiovascular diseases.

This study aimed to define the frequency of aspirin resistance in pediatric patients with CHD and to evaluate the correlation of clinical and laboratory parameters with aspirin resistance.

The study population consisted of 103 patients using aspirin, including 53 cases of cyanotic CHD and 50 cases of noncyanotic CHD. Platelet aggregation was measured by the AggreGuide A-100 ADP Assay.

The prevalence of aspirin resistance was 36.9% in children with CHD. Although aspirin resistance in cyanotic CHD patients (41.5%) was higher than in non-cyanotic patients (32%), the difference was not statistically significant (P = 0.414). There was no significant association between aspirin responsiveness or resistance and the patient’s sex, age, duration of aspirin use, and concomitant medication use. Comparison of the laboratory data of aspirin-responsive and -resistant patients showed no significant difference between these groups, except for albumin (P = 0.032) and serum fibrinogen (P = 0.0001) levels. The fibrinogen level and thromboembolism history were independent risk factors for aspirin resistance. Also, there was a significant correlation between platelet aggregation in peripheral blood smears and aspirin resistance (P = 0.0001).

Our findings suggest that measurement of the serum fibrinogen level and platelet aggregation in blood smears may be the first step to predict aspirin resistance.