Invasive haemodynamics at rest and exercise in cardiac amyloidosis

Abstract 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.