Abnormal conduit artery shear rate patterns during mental stress in patients with cardiometabolic risk

Abstract

Disturbed flow patterns, characterized by the presence of retrograde and oscillatory shear stress, are associated with proatherogenic phenotype. Mental stress consistently induces forearm vasodilation, and evidence suggests that increased cardiometabolic risk (CMR) blunts this response. Importantly, whether this altered vascular response of CMR patients during mental stress impacts the conduit artery shear rate patterns remains unknown. To begin to examine this, 7 CMR patients (36±3 years) and 4 healthy subjects (controls; 34±5 years) underwent a 3‐min mental stress test (Stroop color‐word test), while beat‐to‐beat blood pressure (finger photoplethysmography), brachial blood flow (BF; Doppler ultrasound) and forearm vascular conductance (FVC; BF/mean BP) were continuously monitored. Mental stress significantly increased BP and FVC in controls (P<0.05). In CMR patients, however, while BP was similarly augmented during mental stress, increases in FVC were abolished (−26±12%; P>0.05). Flow patterns were similar between groups at rest but clear differences in retrograde shear (−15.1±4 CMR vs. −3.49±1 s‐1 controls; P<0.05) and oscillatory shear index (0.27±0.04 CMR vs. 0.11±0.06 a.u., controls; P<0.05) were noted during mental stress. These preliminary findings suggest that the blunted vascular responses of CMR patients during mental stress test are associated with disturbed flow patterns.