Coronary Flow Reserve and Small Artery Remodelling in Hypertensive Patients

Abstract

Objective: To evaluate the relationship between subcutaneous small arteries structure and coronary flow reserve in patients with essential hypertension. Methods: Eighteen patients with mild to moderate essential hypertension and normal epicardial coronary arteries were included in the study and underwent a biopsy of the subcutaneous fat from the gluteal region. Subcutaneous small arteries were dissected and mounted on a micromyograph. The media thickness, the normalized internal diameter and the media: lumen ratio were then calculated. Measurement of coronary flow velocity in the left anterior descending artery before and during maximal pharmacological vasodilatation was performed by transesophageal Doppler echocardiography. Results: Mean and peak coronary flow reserve (CFR) as well as minimum coronary resistance were significantly correlated to both media: lumen ratio and normalized internal diameter of subcutaneous small arteries. Those patients with a mean CFR (mCFR) of <2.69 (i.e. 1 SD below the mean of values in our normal reference subjects) had a greater media: lumen ratio and a smaller internal diameter compared with those with a mCFR of ≥2.69. Similarly, patients with a media: lumen ratio of ≥0.109 had a smaller mCFR compared with those with a media: lumen ratio of <0.109. Conclusions: These results are in keeping with the hypothesis of a generalized remodelling of small arteries, that may also be responsible for a reduced coronary vasodilator capacity even in patients with mild to moderate essential hypertension.