Drag reducing polymers may decrease atherosclerosis by increasing shear in areas normally exposed to low shear stress

Area of Science:

• Cardiovascular Science
• Biomedical Engineering
• Pharmacology

Background:

• Atherosclerosis, characterized by plaque formation, often develops in regions of low shear stress within arteries.
• The precise mechanism by which drag reducing polymers (DRPs) inhibit atherosclerosis remains largely unknown.
• Understanding DRPs' mechanism is crucial for developing targeted therapies against atherosclerosis.

Purpose of the Study:

• To investigate whether drag reducing polymers (DRPs) can increase blood flow shear stress in areas typically experiencing low shear stress.
• To elucidate the potential mechanism of DRPs in preventing plaque formation in atherosclerosis.

Main Methods:

• Surgical aortic plication was performed in six dogs to create areas of low shear stress.
• A specialized Doppler ultrasound probe measured blood flow velocity and calculated shear rates before and after DRP administration.
• Paired t-tests were used to compare shear rates, with blood viscosity maintained at a constant 0.04 poise.

Main Results:

• In the plicated (stenosed) aorta, maximum shear rates significantly increased from 9.96/sec to 14.27/sec after DRP administration (P=.0240).
• Conversely, on the unstenosed aortic wall, maximum shear rates decreased from 57.25/sec to 44.80/sec post-DRP (P=.0081).

Conclusions:

• DRPs appear to inhibit atherosclerosis by increasing shear stress in low-flow arterial regions.
• This finding suggests a potential therapeutic pathway for developing novel anti-atherosclerosis pharmaceutical agents.
• Targeting shear stress modulation could be a key strategy in managing cardiovascular disease.