Resident University of Toronto Toronto, Ontario, Canada
Background: Pulmonary Hypertension (PH) influences outcomes for patients with heart failure (HF) and the allocation of advanced heart failure therapies (AHFT). Right heart catheterization (RHC) remains a key step in the evaluation of candidates for AHFT and in measuring and testing the reversibility of PH with a vasodilator challenge (VC). A recent publication from our group highlighted that only a small proportion of patients with severe PH meet the recommended thresholds for VC. Furthermore, contemporary definitions of PH characterize a large proportion of patients who, despite demonstrating PH, do not meet current criteria for VC. Notably, this population also has an increased risk of mortality compared to patients without PH. We hypothesized that changing the criteria for VC to align with contemporary definitions of PH would improve the classification of patients with reversible and non-reversible PH. We undertook a prospective, single-center study to test the implementation of a revised criteria for VC (NCT05672719). This abstract describes recruitment, clinical and hemodynamic characteristics of the study population.
METHODS AND RESULTS: Consecutive patients from the Advanced HF and Transplant Program at Toronto General Hospital were recruited at the time of RHC performed in the Cardiac Catheterization Clinical Research Laboratory at Mount Sinai Hospital. The inclusion criteria was a RHC to evaluate AHFT candidacy for HF with reduced ejection fraction ( < 40%). Our revised criteria for VC with Sodium nitroprusside (SNP) was a mean pulmonary artery pressure > 20 mmHg as long as PAWP > 12 mmHg. We recruited 77 unique patients who underwent 99 RHC procedures. Clinical characteristics of the population included a mean age of 56 ± 10 years, 39% female and a body mass index of 28 ± 5 kg/m2. Table 1 outlines baseline hemodynamic characteristics. Overall, 19 (25%) met the traditional criteria (Severe PH) for VC; and 14 of them received SNP. Using the 2022 European Society of Cardiology’s definition, 21 (27%) did not have PH. This left 37 (48%) patients, who had hemodynamic abnormalities of PH yet did not meet the traditional criteria for VC (Intermediate PH). VC was administered to 19 of these patients.
Conclusion: In this prospective study, we confirmed that up to 3/4 HF patients referred for consideration of AHFT have hemodynamic abnormalities of PH. Changing the threshold to test PH reversibility increased the frequency of VC administered over two-fold. Next steps include analyzing the hemodynamic responses to VC, and the relationship of these responses to AFHT related clinical outcomes.
