Nailfold capillaroscopy is a simple and non-invasive tool used to evaluate nailbed vascular remodeling in a variety of connective tissue diseases. While recent studies have shown that vascular remodeling may be present in extra-pulmonary vasculature in pulmonary arterial hypertension (PAH), it remains unknown whether vascular abnormalities are present in nailfolds of PAH patients. We sought to determine if nailfold capillary abnormalities exist in WHO Group 1 PAH.
Bilateral 2nd to 5th digit nailfolds of PAH, PH, and healthy controls were photographed using Dermlite DL4 dermatoscopes at 10X magnification in well-lit rooms. Demographic, clinical and hemodynamic data were collected. Patients with fewer than 2 fingers showing clearly visible capillaries and nails with visible trauma were excluded. Two independent readers analyzed images and graded for microhemorrhages, enlarged capillaries (>0.09mm capillary width), avascular regions (distance >0.5mm between capillaries in the distal row) and tortuous capillaries. Data were expressed in mean±SEM.
We screened 44 PH patients and included 23 WHO group 1 PAH, 7 Non-Group 1 PH compared to 8 control subjects. Majority of PAH cohort included IPAH (26%), CTD-APAH (22%), and D&T-APAH (17%). Mean age was 51.8±2.9 yrs and 70% were female (Table 1). Majority of patients (N=17, 74%) were NYHA II and III class with a 6MWD of 472±29 meters. Total mean microhemorrhage count per finger (Table 2) appeared to be highest in PAH (0.62±0.2) versus controls (0.27±0.13) or PH (0.3±0.11). Total mean enlarged capillary count was 0.99±0.3 in PAH versus 0.38±0.13 for controls and 0.23±0.07 in PH. Total mean avascular regions and tortuous capillaries were similar across cohorts.
Patients with PAH appear to demonstrate evidence of peripheral vascular abnormalities. Future studies should evaluate nailfold changes in larger cohorts and consider mechanistic implications of these findings.