Brain natriuretic peptide as a biomarker of systemic right ventricular function in patients with transposition of great arteries after atrial switch operation.

Background: Assessment of systemic right ventricular (RV) function is inherently difficult. In adults, plasma brain natriuretic peptide (BNP) level has been shown to reflect systemic ventricular dysfunction. We sought to test the hypothesis that plasma BNP is a biomarker of systemic RV function in patients after atrial switch operation.

Methods: We determined the RV function in 44 patients, 35 after Senning and 9 after Mustard operation, aged 19.7+/-4.0 years, by tissue Doppler echocardiography and determination of myocardial performance index (MPI). The results were compared to the left ventricular function of 14 age-matched controls. Their plasma BNP levels were correlated with indices of systemic ventricular function.

Results: Compared with controls, the patients had greater MPI (p<0.001), lower systemic ventricular free wall-annular early diastolic (p<0.001), late diastolic (p<0.001), and systolic velocities (p=0.001), lower septal-annular early diastolic (p<0.001), late diastolic (p<0.001), and systolic velocities (p<0.001), and higher BNP levels (p=0.03). Plasma BNP levels correlated positively with MPI (r=0.43, p=0.001) and negatively with the free wall- and septal-annular myocardial velocities (r=-0.32 to -0.47, p<0.05). The area under the receiver operating characteristic curve for BNP to detect ventricular dysfunction (MPI >0.45) in patients was 0.67 (p=0.04). A BNP level of 36 pg/ml had a sensitivity of 55%, specificity of 86%, positive predictive value 80%, negative predictive value of 64%, and an accuracy of 70% for detecting systemic ventricular dysfunction.

Conclusions: Plasma BNP has modest accuracy in the detection of systemic RV dysfunction in patients after atrial switch operation.