Small artery structure is an independent predictor of cardiovascular events in essential hypertension

Objective Structural abnormality of resistance arteries is a characteristic pathophysiological phenomenon in essential hypertension and can be assessed in vitro as an increase in the media : lumen ratio (M : L) of isolated small arteries. We have investigated whether M: L is a risk predictor in uncomplicated essential hypertensive patients. Recently, high M: L was demonstrated as a prognostic marker in patients at high cardiovascular risk, including normotensive type 2 diabetic patients. Since diabetes is associated with pressure-independent changes in M: L, the relevance of this finding to essential hypertension has been uncertain. Methods We conducted a follow-up survey of 159 essential hypertensive patients, who had previously been submitted to a M: L evaluation while participating in a clinical trial. They composed a homogeneous moderate-risk group, with no concomitant diseases, and represented 1661 years of follow-up. Results Thirty patients suffered a documented predefined cardiovascular event during follow-up. Increased relative risk (RR) was associated with M: L >= 0.083 (mean level of the hypertensive cohort), RRU2.34 [95% confidence interval (CI) 1.11-4.95], and with M: L >= 0.098 (mean level of a normotensive control group + R2SD), RRU2.49 ( 95% CI 1.21-5.11). Both results remained significant (RR = 2.19, 95% CI 1.04-4.64, and RR= 2.20, 95% CI 1.06-4.56, respectively) when adjusted for Heart Score level (10-year mortality risk-estimate, integrating age, gender, systolic blood pressure, cholesterol and smoking). Conclusion Abnormal resistance artery structure independently predicts cardiovascular events in essential hypertensive patients at moderate risk.