Right ventricular longitudinal strain: a tool for diagnosis and prognosis in light-chain amyloidosis.

OBJECTIVES: Light-chain (AL) amyloidosis can lead to an infiltrative cardiomyopathy with increased wall thickness (IWT) of very poor prognosis. Our primary aim was to analyse the right ventricle (RV) in patients with IWT to discriminate AL amyloidosis from IWT due to hypertrophic cardiomyopathy (HCM) or to arterial hypertension (HTN). Our secondary aim was to assess if RV dysfunction predicts overall mortality in cardiac AL amyloidosis. METHODS: We retrospectively and consecutively compared clinical, biological and echocardiographic data of 315 patients with IWT: 105 biopsy-proven AL amyloidosis patients, 105 patients with HCM and 105 patients with HTN. The prognostic value of these parameters was analysed in the AL amyloidosis group. RESULTS: Free-wall right ventricular longitudinal strain (FWRVLS) worse than -21.2% discriminates AL amyloidosis [area under the curve (AUC) = 0.744)] from patients with IWT due to other aetiologies. In AL amyloidosis, FWRVLS is the strongest echocardiographic prognostic marker with AUC =0.722 and -16.5% as the optimal cut-off value, beyond which overall mortality increases significantly. It is also the only independent echocardiographic predictor of overall mortality (HR =1.113; 95%CI 1.029-1.204; p = .007), even when adjusted to the Mayo stage and global left ventricular longitudinal strain. CONCLUSIONS: FWRVLS should be considered in the diagnostic and prognostic workup in light-chain amyloidosis.

Resting right ventricular function is associated with exercise performance in PAH, but not in CTEPH.

Aims: To assess whether resting right ventricular (RV) function assessed by Global RV longitudinal strain (RVLS) and RV fractional area change (FAC) is associated with exercise performance in pulmonary arterial hypertension (PAH) and in chronic thromboembolic pulmonary hypertension (CTEPH). Methods and results: We prospectively recruited 46 consecutive patients with PAH and 42 patients with CTEPH who were referred for cardio-pulmonary exercise testing (CPET) and transthoracic echocardiography. Resting RV systolic function was assessed with RVLS and FAC. CPET parameters analyzed were percentage of predicted maximal oxygen consumption (VO2max) and the slope of ventilation against carbon dioxide production (VE/VCO2). Spearman correlation was performed between echocardiographic measurements and CPET measurements. In PAH, spearman correlation found an association between RVLS and VE/VCO2 (coefficient = 0.556, P < 0.001) and percentage predicted VO2max (coefficient = -0.393, P = 0.007), while FAC was associated with VE/VCO2 (coefficient = -0.481, P = 0.001) and percentage of predicted VO2max (coefficient = 0.356, P = 0.015). Conversely, in CTEPH, resting RV function was neither associated with percentage of predicted VO2max nor with VE/VCO2, whether assessed by RVLS or FAC. Conclusion: In PAH, resting RV function as assessed by FAC or RVLS is associated with exercise performance and could therefore make a significant contribution to non-invasive assessment in PAH patients. This association is not found in CTEPH, suggesting a disconnection between resting RV function and exercise performance, with implications for the use of exercise measurements as a prognostic marker and clinical/research endpoint in CTEPH.