Optical coherence tomography for hypertensive pulmonary vasculature

Area of Science:

• Cardiovascular Imaging
• Pulmonary Hypertension Research
• Vascular Biology

Background:

• Optical coherence tomography (OCT) is an intravascular imaging technique offering near-histologic resolution.
• Pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) involve significant vascular remodeling.
• Assessing distal pulmonary artery changes is crucial for diagnosing and managing these conditions.

Purpose of the Study:

• To evaluate the utility of OCT in identifying vascular changes associated with PAH and CTEPH.
• To correlate OCT findings with disease severity and hemodynamic parameters.
• To assess OCT's capability in detecting angiographically occult lesions.

Main Methods:

• OCT imaging of distal pulmonary arteries was performed in 87 patients (64 PAH, 23 CTEPH) during right heart catheterization.
• Intimal thickness and luminal diameter were measured.
• Correlation analysis was performed between OCT findings, pulmonary arterial pressure, and pulmonary vascular resistance.

Main Results:

• Intimal thickening was significantly increased in all PAH and CTEPH groups compared to controls (p<0.05).
• An intimal thickness ≥0.176mm demonstrated a 91% positive predictive value for pulmonary hypertension.
• Intravascular webs were identified in 60.9% of CTEPH patients.
• Intimal thickness moderately correlated with pulmonary arterial pressure and resistance (r=0.423, 0.439; p<0.001).

Conclusions:

• OCT provides critical insights into pulmonary arterial remodeling in PAH patients.
• OCT improves the diagnostic accuracy for detecting distal-thrombotic lesions in CTEPH, especially those missed by angiography.
• OCT is a valuable tool for comprehensive assessment of pulmonary hypertension.