Long-Term Natural Course of Patients with Pulmonary Artery Pressures in the Range of 21-24 mmHg: Insights from a Single-Center Study.

Objective: Slightly elevated mean pulmonary artery pressure (mPAP) was previously termed as ''borderline pulmonary hypertension (PH)''. We examined the long-term prognosis of patients with mPAP values between 21 and 24 mmHg, who were referred with the suspicion of pulmonary hypertension.
Methods: Our retrospective study included patients with moderate-to-high echocardiographic risk who underwent right heart catheterization (RHC) between 2008 and 2021 and were followed for at least 1 year. Patients with mPAP <21 mmHg and mPAP 21-24 mmHg were compared. Demographic and clinical characteristics and prognoses of the groups were compared. All-cause mortality over a mean follow-up of 5 years (min 1-max 13 years) was evaluated.
Results: A total of 140 patients (mean age 53.1 ± 14.8 years, female 74.5%) with mPAP values <25 mmHg measured of the 395 diagnostic RHCs. Mean follow-up was 4.92 ± 3.13 years. NT-pro-BNP and 6-min walking distance were better in patients with mPAP <21 mmHg. Echocardiographic findings suggestive of PH were more common in mPAP 21-24 mmHg group (P < 0.05). Both the pulmonary artery wedge pressure and cardiac index values were significantly deteriorated in individuals with mPAP 21-24 mmHg (P = 0.001). All-cause mortality tended to be higher in the borderline PH group but did not reach to statistical significance.
Conclusion: Our single-center observational study revealed that the individuals with an mPAP of 21-24 mmHg tended to have a worser prognosis than those with mPAP of <21 mmHg for up to 13-year follow-up.