Nailfold capillaroscopic changes after six months of antihypertensive therapy in young adults with newly diagnosed essential hypertension: a prospective observational study

Longitudinal data on nailfold capillaroscopic changes in young adults with essential hypertension are limited. This exploratory study evaluated baseline capillaroscopic findings and changes after six months of guideline-directed antihypertensive therapy. In this prospective, single-centre, single-arm observational study, 146 treatment-naive patients with newly diagnosed essential hypertension (82 men; mean age 33.4 ± 5.8 years) underwent 24-hour ambulatory blood pressure monitoring and nailfold capillaroscopy at baseline and six months. No normotensive or untreated comparator group was included. Images were evaluated by two rheumatologists blinded to patient identity and clinical data, but not to time point. The change in capillary density was the primary longitudinal outcome; all remaining analyses were exploratory, and p values were adjusted using the Benjamini–Hochberg false discovery rate procedure. At baseline, left ventricular hypertrophy was present in 24.7% of patients and hypertensive retinopathy in 20.5%. All ambulatory blood pressure parameters decreased significantly after six months (all FDR-adjusted p < 0.001). The prevalence of dilated capillaries decreased from 32.2% to 16.1%, avascular areas from 10.5% to 2.1%, microaneurysms from 12.6% to 3.5%, and microhaemorrhages from 30.8% to 6.3% (all FDR-adjusted p ≤ 0.003). Median capillary density increased from 29 to 35 loops/mm² (FDR-adjusted p < 0.001). However, blood pressure reduction was not independently associated with capillary density change after correction for multiple testing, and a multivariable regression model explained only a small proportion of the variance (adjusted R² = 0.069). Capillaroscopic abnormalities were common at diagnosis and less frequent after six months. However, given the single-arm design and the absence of an association between blood pressure reduction and capillaroscopic change, treatment-induced microvascular reversibility cannot be inferred. Controlled studies are needed.