Background: Structural alterations in the microcirculation may be considered an important mechanism of organ damage. An increased tunica media to internal lumen ratio of subcutaneous small-resistance arteries (M:L) may predict the development of cardiovascular events in a high-risk population. However, it is not known whether structural alterations of small arteries may also predict major cardiovascular events.
Methods: Three hundred three subjects were included in the present study. There were 65 normotensive subjects, 111 patients with essential hypertension (33% of them with diabetes mellitus), 109 patients with secondary forms of hypertension, and 18 normotensive diabetic patients. Small-resistance arteries were dissected from subcutaneous fat biopsies and mounted on an isometric myograph, and the M:L was measured. Subjects were reevaluated after an average follow-up time of 6.9 years to assess the occurrence of cardio-cerebrovascular events.
Results: Eleven subjects died of a fatal cardio-cerebrovascular event (FCE), 14 had a major, nonfatal cardiovascular event (stroke or myocardial infarction) (SMI), 23 had a minor cardiovascular event (MCE), and 255 had no cardiovascular event (NCE). A significant difference was observed in M:L and in event-free survival between patients with FCEs+SMIs+MCEs and those with NCE and between patients with FCEs+SMIs and those with NCE. Similar results were obtained by restricting the analysis to patients with essential hypertension.
Conclusions: Structural alterations of small-resistance arteries may predict FCE and SMI. The prognostic role of small-resistance artery structure also applies to medium-risk patients with essential hypertension, at least when MCEs are included in the analysis.