Abstract Body (Do not enter title and authors here): Aim: Right ventricle to pulmonary circulation (RV-Pc) uncoupling represents a mainstay in staging progression of heart failure (HF), being an independent predictor of mortality. In addition, N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) is a well-established diagnostic and prognostic serum biomarker. In lack of clear clinical evidences on the relationship between exercise levels of NT-proBNP and RV-Pc uncoupling, this represents the aim of our investigation.

Methods and Results: A cohort of 13 HF stable patients (mean age 71.6 ± 8.1; 48% female, mean left ventricular ejection fraction 57±13%) underwent maximal exercise stress echocardiographic and cardiopulmonary exercise testing (iCPET) with RV 3D-imaging analysis and were compared with a control population. Natriuretic peptides levels were obtained at rest and peak exercise. RV-Pc coupling was addressed by using the length-force relationship TAPSE/PASP ratio (tricuspid annular plane systolic/excursion pulmonary arterial systolic pressure). As expected, HF patients exhibited a higher level of NT-pro-BNP compared to controls (mean 831 ng/ml vs 131 ng/ml, at rest; mean 793.3 vs 138 ng/ml at peak). In HF, TAPSE/PAPS at peak exercise decreased compared to rest (0.73 ± 0.19 vs 0.47 ± 0.15 respectively) with an inverse correlation between NT-pro-BNP and TAPSE/PAPS exercise (r=0.60, p<0.01). See figure.

Conclusion: Our investigation demonstrates a parallel trend between peak TAPSE/PASP and peak NT-pro-BNP. These findings suggest that natriuretic peptide may serve as a surrogate of underlying RV to Pc uncoupling and the right heart plays a crucial role in the biomarker activity during maximal exercise in advanced HF.