Sublingual microcirculation in pulmonary arterial hypertension.

Area of Science:

• Cardiovascular Research
• Pulmonary Medicine
• Microcirculation Studies

Background:

• Pulmonary arterial hypertension (PAH) is a severe condition characterized by high blood pressure in the pulmonary arteries, leading to right ventricular failure and increased mortality.
• Understanding the systemic microvascular alterations in PAH is crucial for developing effective therapeutic strategies.

Purpose of the Study:

• To investigate potential changes in the sublingual microcirculation of patients diagnosed with PAH.
• To compare microcirculatory parameters between PAH patients and age- and sex-matched healthy controls.

Main Methods:

• Utilized a CapiScope Handheld Video Capillaroscope to assess sublingual microvasculature.
• Measured microvasculature density, flow index, tortuosity, and curvature in PAH patients and controls.
• All measurements were performed by blinded investigators immediately after right heart catheterization.

Main Results:

• Patients with PAH demonstrated a significantly lower sublingual microvasculature flow index compared to controls (2 ± 0.66 vs. 2.7 ± 0.37, P < 0.001).
• A higher heterogeneity index was observed in PAH patients (0.63 ± 0.63 vs. 0.25 ± 0.25, P = 0.04).
• Sublingual microvasculature exhibited increased tortuosity in PAH patients (tort 0: 45 ± 19 vs. 23.6 ± 12, P = 0.001; tort 1: 0.2 ± 0.16 vs. 0.06 ± 0.04, P < 0.001), while density remained similar.

Conclusions:

• The sublingual microcirculation is altered in PAH patients, characterized by reduced flow and increased tortuosity.
• These findings suggest that sublingual capillaroscopy may offer insights into PAH pathophysiology.
• Further research is necessary to determine the clinical utility of this methodology for disease prognosis and treatment response assessment in PAH.