Potential Clinical Impact of Revised Pulmonary Hypertension Definitions at Moderate Altitude

Area of Science:

• Cardiology
• Pulmonology
• Medical Diagnostics

Background:

• Pulmonary hypertension (PH) and precapillary PH definitions were revised in 2018 and 2022.
• Previous definitions used a mean pulmonary arterial pressure (mPAP) ≥ 25 mm Hg and pulmonary vascular resistance (PVR) ≥ 3 Wood units.
• Revised definitions lowered the mPAP threshold to 20 mm Hg and PVR to > 2 Wood units.

Purpose of the Study:

• To evaluate the impact of revised PH and precapillary PH definitions at moderate altitude.
• To determine if revised definitions capture similar patient populations at altitude compared to sea level.
• To assess the prognostic implications of these revised definitions on patient mortality and disease progression.

Main Methods:

• Analysis of hemodynamic data from right heart catheterization procedures in 2,382 patients residing at 1,609 m.
• Extraction of clinical data on PH diagnosis, progression, and mortality from electronic medical records and the National Death Index.
• Comparison of patient cohorts and mortality outcomes based on pre-2018, post-2018, and post-2022 diagnostic criteria.

Main Results:

• Applying the post-2018 definition significantly reduced the prevalence of PH diagnoses compared to pre-2018 criteria (59.2% vs. 12.8%).
• The post-2022 definition increased the prevalence of precapillary PH diagnoses (P < .05).
• Patients diagnosed with PH under revised criteria exhibited lower mortality than pre-2018 PH patients but higher than those without PH. Post-2022 precapillary PH patients showed lower mortality compared to pre-2018 precapillary PH patients.

Conclusions:

• Revised PH definitions at moderate altitude identify patients with mortality risks comparable to sea-level findings.
• The post-2022 precapillary PH definition identifies a population with lower mortality and no significant disease progression.
• Further research is warranted to understand the clinical implications and management of this newly identified precapillary PH population at altitude.