Sublingual microcirculation in pulmonary arterial hypertension

Dababneh L, Cikach F, Alkukhun L, Dweik RA, Tonelli AR.(2014) Sublingual microcirculation in pulmonary arterial hypertension. Ann Am Thorac Soc. 11(4):504-12. PMID: 24601682. PMCID: PMC4225801.

RATIONALE:  Pulmonary arterial hypertension (PAH) is a pulmonary vasculopathy that leads to failure of the right ventricle and premature death.
OBJECTIVES:  To determine whether the sublingual microcirculation is affected in patients with PAH compared with healthy age- and sex-matched control subjects.
METHODS:  Using the CapiScope Handheld Video Capillaroscope we measured the sublingual microvasculature density, flow index, tortuosity, and curvature. Videos were acquired immediately after right heart catheterization, and determinations were made off-line by investigators blinded to the group assignment or hemodynamics.
MEASUREMENTS AND MAIN RESULTS:  In this cross-sectional pilot study, we included 26 patients with PAH (age, mean ± SD, 56.7 ± 10 yr; 77% women) and 14 healthy control subjects (age, 53.1 ± 12 yr; 71% women). Sublingual microvasculature flow index was lower (2 ± 0.66 vs. 2.7 ± 0.37, P < 0.001) with higher heterogeneity index (0.63 ± 0.63 vs. 0.25 ± 0.25, P = 0.04) in patients with PAH than control subjects. Microvasculature density was similar between the groups, but tortuosity was more pronounced in patients than control subjects (tort 0: 45 ± 19 vs. 23.6 ± 12, P = 0.001 and tort 1: 0.2 ± 0.16 vs. 0.06 ± 0.04, P < 0.001).
CONCLUSIONS:  Patients with PAH showed lower sublingual microvasculature flow index and higher tortuosity compared with healthy age- and sex-matched control subjects. Further investigations are needed to assess whether this methodology can provide information on disease prognosis and/or response to therapy in this condition.

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