Tafamidis induces improvement of right ventricle-to-pulmonary artery coupling in patients with transthyretin amyloid cardiomyopathy

Background:

Patients with transthyretin amyloid cardiomyopathy (ATTR-CM) often develop right ventricular (RV) dysfunction even at early disease stages. Right ventricle-to-pulmonary artery (RV-PA) coupling has emerged as a robust tool to evaluate RV dysfunction and has been reported as an important prognostic factor in patients with ATTR-CM. However, the potential of tafamidis to improve RV-PA coupling has not been previously investigated.

Objective:

The purpose of this study was to evaluate the effect of tafamidis on RV-PA coupling over 12 months of treatment.

Methods:

This retrospective study included 93 patients with ATTR-CM treated with 61 mg tafamidis daily who underwent multimodality imaging evaluation at baseline by cardiovascular magnetic resonance (CMR) and speckle tracking echocardiography. All patients underwent 12 months follow-up including echocardiographic assessment of RV-PA coupling. RV-PA coupling was assessed using the tricuspid annular plane systolic excursion/ pulmonary artery systolic pressure (TAPSE/PASP) ratio. A significant improvement of RV-PA coupling was defined as a >10 % improvement in RV-PA coupling from baseline.

Results:

At baseline, patients presented with a mean RV ejection fraction of 49±5% and a reduced TAPSE/PASP ratio of 0.4±0.1 mm/mmHg. 12 months after tafamidis initiation, 18.3% of patients experienced a significant improvement in TAPSE/PASP ratio from 0.42±0.05 mm/mmHg to 0.54±0.07 mm/mmHg, P=0.001. In multivariable regression analysis, baseline NT-proBNP (HR 0.998, 95% CI 0.997-0.999, P=0.003) and CMR derived RV end-systolic volume (HR 0.88, 95% CI 0.75-0.99, P=0.041) independently predicted improvement of RV-PA coupling.

Conclusion:

Patients with ATTR-CM treated with tafamidis at an earlier stage of the disease experience significant improvement in RV-PA coupling.