Large artery stiffness and carotid flow pulsatility in stroke survivors

Objective: Aortic stiffness is increased in lacunar stroke. The precise mechanism linking aortic stiffness to symptomatic lacunar stroke is not well understood. The aim of this study was to compare the effects of aortic stiffness, carotid stiffness, central blood pressure, and cerebrovascular resistance on carotid flow pulsatility according to stroke subtype. Methods: Two hundred and one consecutive patients were examined 13 months after hospitalization for their first-ever ischemic stroke. The stroke subtype was classified using the Causative Classification of Stroke System. Carotid-femoral pulse wave velocity (PWV) was used as a measure of aortic stiffness. Common carotid flow pulsatility was expressed as resistive index. Central blood pressure was measured using applanation tonometry. Results: Complete data were available for 174 patients (mean age horizontal ellipsis 67 +/- 10 years, 64% men). In patients with lacunar stroke, aortic PWV was higher (13.11 +/- 2.74 m/s) than in individuals with large artery atherosclerosis (9.98 +/- 1.87 m/s, P <0.001), cardioembolic (11.31 +/- 3.18 m/s, P = 0.04) or cryptogenic stroke (11.13 +/- 3.2 m/s, P = 0.01). Similarly, central SBP and resistive index were higher in patients with lacunar stroke (145 +/- 23 mmHg and 0.80 +/- 0.04, respectively) than those with large artery atherosclerosis (128 +/- 18 mmHg, P <0.01 and 0.74 +/- 0.07, P <0.01, respectively) or cryptogenic stroke (132 +/- 18 mmHg, P <0.01 and 0.76 +/- 0.07, P <0.05, respectively). In multivariate analysis, aortic stiffness and central pulse pressure were the main determinants of resistive index independent of stroke subtype. Conclusion: Our results suggest that aortic stiffening, by reducing the buffering function of the aorta and thereby increasing the transmission of pressure and flow pulsatility into the cerebral arterioles, may contribute to the pathogenesis of lacunar stroke.