Right Ventricular to Pulmonary Artery Uncoupling Is Associated With Impaired Exercise Capacity in Patients With Transthyretin Cardiac Amyloidosis

• Published in: Circulation Journal p. CJ-24-0402
• Main Authors: Hashimoto, Toru, Ikuta, Kei, Yamamoto, Shoei, Yoshitake, Tomoaki, Suenaga, Tomoyasu, Nakashima, Shunsuke, Kai, Takashi, Misumi, Kayo, Fujino, Takeo, Shinohara, Keisuke, Matsushima, Shouji, Atsumi, Rina, Isoda, Takuro, Kinugawa, Shintaro, Abe, Kohtaro
• Format: Journal Article
• Language: English
• Published: Japan The Japanese Circulation Society 28.09.2024
• Subjects: Cardiopulmonary exercise test; Exercise capacity; Right ventricular dysfunction; Right ventricular-pulmonary artery coupling; Transthyretin cardiac amyloidosis; Cardiopulmonary exercise test; Right ventricular-pulmonary artery coupling; Exercise capacity; Transthyretin cardiac amyloidosis; Right ventricular dysfunction
• ISSN: 1346-9843; 1347-4820; 1347-4820
• DOI: 10.1253/circj.CJ-24-0402

Background: Exercise capacity is related to mortality and morbidity in heart failure (HF) patients. Determinants of exercise capacity in transthyretin cardiac amyloidosis (ATTR-CA) have not been established.Methods and Results: This single-center study retrospectively evaluated ATTR-CA patients and patients with non-amyloidosis HF with preserved/mildly reduced ejection fraction (HFpEF/HFmrEF) (n=32 and n=51, respectively). In the ATTR-CA group, the median age was 75.5 years (interquartile range [IQR] 71.3–78.8 years), 90.6% were male, and the median left ventricular (LV) ejection fraction was 53.5% (IQR 41.4–65.6%). Cardiopulmonary exercise tests revealed a median peak oxygen consumption and anaerobic threshold of 15.9 (IQR 11.6–17.4) and 10.6 (IQR 8.5–12.0] mL/min/kg, respectively, and ventilatory efficiency (minute ventilation/carbon dioxide production [V̇E/V̇CO2] slope) of 35.5 (IQR 32.0–42.5). Among exercise variables, V̇E/V̇CO2slope has the greatest prognostic value. Univariate analysis revealed a significant correlation between V̇E/V̇CO2slope and age, LV global longitudinal strain, tricuspid annular plain systolic excursion/pulmonary arterial systolic pressure (TAPSE/PASP) ratio, and mixed venous oxygen saturation. In multivariate analyses, the TAPSE/PASP ratio was an independent predictor of V̇E/V̇CO2slope (95% confidence interval −44.5, −10.8; P=0.0067). In non-amyloidosis HFpEF/HFmrEF patients, the TAPSE/PASP ratio was not independently correlated with V̇E/V̇CO2slope.Conclusions: Right ventricular–pulmonary artery coupling estimated by the TAPSE/PASP ratio determines exercise capacity in ATTR-CA patients. This highlights the importance of early therapeutic intervention against underappreciated right ventricular dysfunction associated with ATTR-CA.