Rarefaction of skin capillaries in patients with anginal chest pain and normal coronary arteriograms.

AIMS Patients with arterial hypertension often have a reduction in capillary density (rarefaction) and a reduction in coronary flow reserve because of functional and structural alterations of the coronary microcirculation. Patients with chest pain and normal coronary arteriograms may have coronary microvascular dysfunction, but it is not known whether capillary rarefaction plays a role in the pathogenesis of this syndrome. The aim of this study was to compare capillary density in hypertensive and normotensive subjects with anginal chest pain and normal coronary arteriograms vs asymptomatic hypertensives and healthy controls. METHODS AND RESULTS We studied 49 patients with typical anginal chest pain, positive exercise testing and normal coronary arteriograms; 22 were hypertensive and 27 were normotensive. We used intra-vital video-microscopy to examine the skin of the dorsum of the middle finger of the non-dominant hand before and after maximization of perfused capillaries with venous congestion. Mean capillary density was significantly lower in patients with chest pain and normal coronary arteriograms independent of their blood pressure level, compared to normotensive healthy controls. Differences were found both at baseline [51+/-2 (hypertensive) and 52+/-2 (normotensive) vs 65+/-2 (controls) per 0.56 mm(2) respectively], (P<0.0001) and after maximization [57+/-3 (hypertensive) and 59+/-2 (normotensive) versus 75+/-3 (controls) respectively] (P<0.0001). CONCLUSIONS Skin capillary density is significantly lower in patients with chest pain and normal coronary arteriograms compared to normotensive controls. The pathophysiological importance of capillary rarefaction in patients with chest pain and normal coronary arteriograms remains unknown. Further studies are needed to determine whether the abnormality is associated with myocardial flow disturbances such that the findings can be extended to the heart.