Abstract 14140: Flow-dependent Cardiac Dysfunction and Pressure-dependent Endothelial Activation in Patients With Atrial Septal Defect
Background and objectives: Pulmonary blood flow and pulmonary arterial pressure are increased to a variable extent in patients with atrial septal defect (ASD). However, the way these variables influence specific markers of cardiac and endothelial dysfunction is not completely understood. We therefore analyzed the possible impact of the disease duration (patient age), size of the communication and magnitude of hemodynamic changes on patient’s functional capacity, and circulating levels of brain natriuretic peptide (BNP, a marker of cardiac dysfunction) and von Willebrand factor antigen (VWF:Ag, a marker of endothelial activation).
Patients and methods: Forty patients were enrolled (age 13 to 69 years, median 47.5 years), with ASD diameter ranging from 8 to 35 mm (median 20 mm). The pulmonary-to-systemic blood flow ratio (Qp/Qs) was 1.05 to 5.47 (median 2.66) and pulmonary artery systolic pressure (PAPsys) of 30 to 106 mmHg (median 41 mmHg). Plasma BNP (chemiluminescent immunoassay), VWF:Ag (enzyme-linked immunoassay) and the six-minute walked distance (6MWD, a measure of physical capacity) were analyzed as dependent variables in the regression models, whereas patient age, the ASD diameter, the Qp/Qs ratio and PAPsys were selected to be investigated as independent factors.
Results: Most patients were in functional class II (6MWD 550 ± 89m). The physical capacity was influenced only by the age (r = -0.34, p=0.0324). Plasma BNP (6 to 1953 pg/ml in patients, normal level < 100 pg/ml) was directly related to the age (r=0.34, p=0.0329) and Qp/Qs ratio (r=0.36, p=0.0233), but was not influenced by PAPsys. Plasma VWF:Ag was increased in patients (117±16 U/dL vs. 88±21 U/dL in controls, p<0.0001), but its biological activity was decreased (66±21% vs. 101±44% in controls, p=0.0002). Levels of VWF:Ag were directly related to patient’s age (r=0.38, p=0.157) and PAPsys (r=0.77, p<0.0001), but not influenced by the Qp/Qs ratio. The ASD size itself did not influence any of the dependent variables.
Conclusions: In patients with ASD, cardiac and endothelial functions seem to be affected differentially by hemodynamic changes. Alternatively, those with a more impressive endothelial activation might be at a higher risk of developing a high pulmonary pressure profile.
- © 2013 by American Heart Association, Inc.