Left ventriculo-arterial coupling in a contemporary cohort of patients with wild-type transthyretin cardiac amyloidosis treated with tafamidis

Background: Wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM) is characterized by a labile equilibrium between preload and afterload. A tailored approach to supporting medical therapy based on noninvasive parameters able to describe the properties of both heart and systemic vasculature, and their interactions is required. However, data on ventriculo-arterial coupling (VAC) in ATTRwt-CM is lacking. Objectives: To describe ventriculo-arterial coupling (VAC) and its clinical correlates in a contemporary cohort of patients with ATTRwt-CM. Methods: The VAC, defined as the ratio between arterial (Ea) and ventricular elastance (Ees) was evaluated noninvasively using the single-beat algorithm based on arm cuff blood pressure, Doppler stroke volume, pre-ejection time and total ejection time. Results: The study included 114 patients treated with the transthyretin stabilizer tafamidis from a national referral centre (median age 79 years; 89% males). Median values were 1.48 (1.22-1.84) mmHg/ml for Ea, 1.86 (1.49-2.29) mmHg/ml for Ees, and 1.24 (0.96-1.58) for VAC. Patients with upper-tertile VAC showed worse clinical (National Amyloidosis Centre (NAC)/Mondor stage, p < 0.001), laboratory (NT-pro-B-type natriuretic peptide levels, p < 0.001), instrumental features (left ventricular ejection fraction and stroke volume, p = 0.0001 for both), and they received more intensive heart failure supportive therapies. The Ea/Ees ratio, but not its single components, was associated with NT-proBNP levels. Finally, the Ea/Ees ratio was an independent determinant of a high NAC/Mondor stage at both univariate (OR[95% CI]:15.39[3.51-67.35], p < 0.001) and multivariate (OR[95% CI]:11.26[1.98-63.81], p = 0.006) logistic regression analyses. Conclusion: In ATTRwt-CM patients, arterial and ventricular elastances and VAC are independent predictors of worse clinical status and more advanced disease stage.