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 >or= 0.083 (mean level of the hypertensive cohort), RR = 2.34 [95% confidence interval (CI) 1.11-4.95], and with M: L >or= 0.098 (mean level of a normotensive control group + 2SD), RR = 2.49 (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.

Small artery structure during antihypertensive therapy is an independent predictor of cardiovascular events in essential hypertension.

OBJECTIVE: Structural changes of small resistance arteries occur early in the disease process of essential hypertension and predict cardiovascular events in previously untreated patients. We investigated whether on-treatment small artery structure also identifies patients at elevated risk despite normalization of blood pressure (BP). METHODS: We conducted a long-term follow-up survey of cardiovascular events in 134 moderate-risk patients with 9-12 months of well treated essential hypertension. All participants underwent subcutaneous biopsies with determination of small artery structure in terms of media to lumen ratio (M : L) before and during treatment. RESULTS: After 9-12 months of treatment SBP was lowered from 164 ± 15 to 134 ± 14 mmHg (P < 0.01) and M : L reduced from 0.084 ± 0.028 to 0.075 ± 0.024 (P < 0.01). Mean follow-up hereafter was 15 years representing a total of 2035 years for the entire cohort. During this period 47 patients suffered a predefined cardiovascular event. For patients with on-treatment M : L above the mean value of the cohort (≥0.075), the hazard ratio was 2.14 [95% confidence interval (CI) 1.19-3.84, P = 0.01] and also those with M : L above mean +2SD of a normotensive population (≥0.098) had an elevated risk (hazard ratio 2.99, 95% CI 1.60-5.58, P < 0.01). Both results were adjusted for heart score (a 10-year mortality risk estimate integrating age, sex, smoking status, cholesterol level and SBP). Analysis of changes in M : L during treatment showed significantly higher event rates among patients with increased M : L and vice versa (hazard ratio 1.36 per 25% change, 95% CI 1.07-1.73, P = 0.013). CONCLUSION: On-treatment small artery structure identifies individuals still at increased cardiovascular risk despite long-term BP normalization and may be an additional target for therapy to prevent cardiovascular events.