Holt MF;  Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
Flø A;Ravnestad H; Bjørnø V; Gullestad L; Andreassen AK; DBroch K; Gude E

ESC heart failure [ESC Heart Fail] 2023 Dec 29.
Date of Electronic Publication: 2023 Dec 29.

Aims: Our aim was to investigate haemodynamics at rest and during exercise in patients with transthyretin cardiomyopathy (ATTR-CM) in light of the 2022 European Society of Cardiology (ESC) and European Respiratory Society (ERS) guidelines on pulmonary hypertension (PH).
Methods and Results: We performed right heart catheterization (RHC) in 57 subjects with ATTR-CM. The proportion of patients with PH was 77% according to the 2022 guidelines versus 47% when applying the 2015 guidelines. Isolated post-capillary PH and combined pre- and post-capillary PH were most prevalent. Thirty-six patients underwent a supine bicycle cardiopulmonary exercise test during RHC. Exercise-induced PH was defined as an increase in mean pulmonary arterial pressure from rest to exercise per increase in cardiac output (ΔmPAP/ΔCO) of > 3 mmHg/L/min. An increase in pulmonary arterial wedge pressure per change in cardiac output (ΔPAWP/ΔCO) from rest to exercise >2 mmHg/L/min was considered suggestive of post-capillary exercise-induced PH. All but two patients who exercised during RHC developed exercise-induced PH. The median ΔmPAP/ΔCO was 7.2 mmHg/L/min and ΔPAWP/ΔCO was 5.1 mmHg/L/min. The median ΔRAP/ΔCO was 3.6 mmHg/L/min and ΔRAP/ΔPAWP was 0.6 mmHg/L/min.
Conclusions: Most patients with ATTR-CM have isolated post-capillary or combined pre- and post-capillary PH at rest, and almost all patients develop exercise-induced PH with a large post-capillary component. There was a pronounced, but balanced increase in atrial pressures on exercise.