Pulmonary hypertension in chronic obstructive pulmonary disease. Multivariate analysis

Area of Science:

• Cardiology
• Pulmonology
• Medical Diagnostics

Background:

• Pulmonary hypertension (PH) is a serious complication of stable chronic obstructive pulmonary disease (COPD).
• Accurate prediction of PH in COPD patients is crucial for timely intervention and management.

Purpose of the Study:

• To evaluate the severity of PH in COPD patients using right cardiac catheterization.
• To identify predictors of PH among anthropometric, spirometric, radiographic, and gas-exchange variables.
• To assess the diagnostic value of arterial blood gas criteria for PH in COPD.

Main Methods:

• Right cardiac catheterization was performed on 89 stable COPD patients at rest and during exercise.
• Correlation and stepwise multiple linear regression analyses were used to identify predictors of mean pulmonary arterial pressure (mPAP).
• Arterial blood gas (PaO2, PaCO2), spirometric, and radiographic data were analyzed.

Main Results:

• Thirty-one patients had resting PH (mPAP ≥ 20 mm Hg); three developed exercise-induced PH (mPAP ≥ 35 mm Hg).
• Arterial oxygen pressure (PaO2) at maximum exercise was highly correlated with resting mPAP (r = -0.67).
• Right descending pulmonary artery diameter and PaCO2 also contributed to mPAP prediction. Arterial blood gas thresholds (PaO2 < 60 mm Hg or PaCO2 > 40 mm Hg) were accurate PH predictors, outperforming spirometry and radiography.

Conclusions:

• Arterial blood gas measurements, specifically PaO2 and PaCO2, are valuable and superior predictors of pulmonary hypertension in COPD patients.
• Spirometric indices and radiographic findings showed poor correlation with PH severity and were not useful predictors.
• The study highlights the utility of arterial blood gas criteria for early PH diagnosis in COPD, preceding overt cor pulmonale.