Renin Angiotensin System Inhibitors Reduce Aortic Stiffness and Flow Reversal After a Cryptogenic Stroke

Abstract

Background: Blood flow reversal is a possible mechanism for retrograde embolism in the setting of high-risk atherosclerotic plaques in the descending aorta (DAo). Evidence suggests that pulse wave velocity (PWV) is a determinant of blood flow reversal and can be reduced by the destiffening effect of renin-angiotensin system inhibitors (RASI).

Purpose: To evaluate the impact of antihypertensive therapy on in vivo changes in PWV and flow reversal in patients with cryptogenic stroke.

Study type: Prospective.

Population: Sixteen patients (69 ± 9 years; 10 males) included after cryptogenic stroke.

Field strength/sequence: 3T. 4D flow sequence (temporal resolution = 19.6 msec) ASSESSMENT: Patients underwent aortic MRI at baseline and at 6-month follow-up. Patients received standard-of-care antihypertensive therapy that were classified as RASI vs. non-RASI medications (ie, destiffening vs. nondestiffening).We compared aortic PWV, flow reversal fraction (FRF), aortic measurements, cardiac function, and other aortic and cardiac measurements in the antihypertensive therapy groups.

Statistical tests: Two-tailed paired or unpaired Student's t-tests (normal distributions) or Wilcoxon tests (nonnormal distribution). Univariate correlations using Pearson correlation coefficients.

Results: There was a significant decrease in PWV in the RASI (n = 10) group (9.4 ± 1.6 m/s vs. 8.3 ± 1.9 m/s; P < 0.05), as well as FRF (18.6% ± 4.1% vs. 16.3% ± 4.0%; P < 0.05) between baseline and the 6-month MRI studies. There were no changes in PWV or FRF in the non-RASI (n = 6) group (P = 0.146 and P = 0.32). A decrease in FRF was significantly correlated with a decrease in PWV (r = 0.53; P < 0.05).

Data conclusion: The findings of our study suggest that RASI therapy after cryptogenic stroke resulted in a decrease of blood flow reversal and aortic stiffness.

Evidence level: 1 TECHNICAL EFFICACY STAGE: 4.

Keywords: aortic stiffness; pulse wave velocity; renin-angiotensin system inhibitors; stroke.