Rotational thromboelastometry (RT) and whole blood impedance aggregometry (IA) may have utility in identifying coagulation patterns in patients with cyanotic congenital heart diseases (CCHD) compared with patients with noncyanotic congenital heart diseases (NCCHD), according to a study published in the American Journal of Cardiology.

CCHD can give rise to disruptions in coagulation and may predispose patients to both thrombosis and excessive bleeding.

The research included 76 patients with CCHD and 48 patients with NCCHD from an outpatient facility in Germany. Blood samples were taken from each patient and subjected to multiple routine blood tests, as well as RT to measure coagulation characteristics and IA to assess platelet function.

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Numerous differences were found between CCHD and NCCHD for the features examined. Patients with CCHD showed significantly lower mean oxygen saturation compared with patients with NCCHD (81.5% vs 98%; P <.001). Eisenmenger syndrome was present in 51.3% of patients with CCHD but in no patients with NCCHD. Pulmonary hypertension was present in 72% of patients with CCHD compared with 2% of patients with NCCHD.

Thrombocytopenia was more common in patients with CCHD (P <.001). Measures of hematocrit, hemoglobin, and reticulocytes were also significantly higher with CCHD (P <.001 for each).

RT and IA analyses were effective at showing differences in blood samples between the 2 patient groups. Higher platelet counts showed stronger coagulation metrics; the reverse was true for hematocrit. Extended clotting times and lower clot firmness were found in RT analyses of patients with CCHD compared with patients with NCCHD.

Platelet aggregation was significantly lower for patients with CCHD in all tests and was lower than the reference range for most patients with CCHD, even after the use of triggering agents.

RT and IA analyses showed that blood from patients with CCHD had a marked tendency for hypocoagulability. Patients with NCCHD also showed some hypocoagulability, but to a much lesser degree and frequency than those with CCHD.

The authors noted that thromboembolism remains a risk with CCHD, although CCHD was not found to be associated with hypercoagulability. They concluded that “RT and IA analysis facilitate measurement of coagulation and platelet function in CCHD.”


  1. Pujol C, Stöckl A, Mebus S, et al. Value of rotational thromboelastometry and impedance aggregometry for evaluating coagulation disorders in patients with cyanotic and nongenetic congenital heart disease [published online February 23, 2019]. Am J Cardiol. doi: 10.1016/j.amjcard.2019.02.031