Implication of the new definition of pulmonary hypertension in patients evaluated for heart transplantation

Background: The 2018 World Symposium on Pulmonary Hypertension (WSPH) changed the definition of pulmonary hypertension (PH) with a new threshold of mean pulmonary artery pressure (mPAP) above 20 mmHg.

Objective: To evaluate the profile and prognosis of patients with chronic heart failure (HF) considered for heart transplantation with the new definition of PH.

Methods: Patients with chronic HF considered for heart transplantation were classified as mPAP_≤20mmHg, mPAP _{20-25 mmHg}, and mPAP_≥25mmHg. Using a multivariate Cox model, we compared the mortality of patients with mPAP_20-25mmHg, and mPAP_≥25mmHg versus those with mPAP_≤20mmHg.

Results: Of 693 patients with chronic HF considered for heart transplantation, 12.7%, 77.5% and 9.8% were classified as mPAP_20-25mmHg, mPAP_{≥ 25mmHg} and mPAP_≤20mmHg. Patients of mPAP ≥ _25mmHg and mPAP _{20-25 mmHg} categories were older than mPAP ≤ _{20 mmHg} (56 versus 55 and 52 year-old, p = 0.02) with more frequent co-morbidities. Within 2.8 years, the mPAP_20-25mmHg category displayed a higher risk of mortality compared with those of the mPAP_≤20mmHg category (aHR 2.75, 95% CI 1.27-5.97, p = 0.01). Overall, the new PH definition using a threshold of mPAP >20 mmHg was associated with a higher risk of death (adj HR 2.71, 95% CI 1.26-5.80) than the previous definition (mPAP >25 mmHg, aHR: 1.35 95% CI 1.00-1.83, p = 0.05).

Conclusions: One out of 8 patients with severe HF are reclassified as having PH following the 2018 WSPH. Patients with mPAP_20-25 evaluated for heart transplantation displayed significant co-morbidities and high mortality rates.