Long-term electric activation of the carotid sinus baroreflex in dogs with advanced heart failure increased LV ejection fraction by 4.0±2.4% compared to a 2.8±1.0% reduction in controls (P<0.05).
Does chronic bilateral carotid sinus baroreflex activation improve LV function and attenuate remodeling in dogs with advanced chronic heart failure?
In a canine model of advanced heart failure, chronic carotid sinus baroreflex activation improved LV function and partially reversed remodeling at the global, cellular, and molecular levels.
Absolute Event Rate: 4% vs -2.8%
p-value: p=<0.05
BACKGROUND: Autonomic abnormalities exist in heart failure and contribute to disease progression. Activation of the carotid sinus baroreflex (CSB) has been shown to reduce sympathetic outflow and augment parasympathetic vagal tone. This study tested the hypothesis that long-term electric activation of the CSB improves left ventricular (LV) function and attenuates progressive LV remodeling in dogs with advanced chronic heart failure. METHODS AND RESULTS: Studies were performed in 14 dogs with coronary microembolization-induced heart failure (LV ejection fraction ≈25%). Eight dogs were chronically instrumented for bilateral CSB activation using the Rheos System (CVRx Inc, Minneapolis, Minn) and 6 were not and served as controls. All dogs were followed for 3 months, and none received other background therapy. During follow-up, treatment with CSB increased LV ejection fraction 4.0±2.4% compared with a reduction in control dogs of −2.8±1.0% (P<0.05). Similarly, treatment with CSB decreased LV end-systolic volume -2.5±2.7 mL compared with an increase in control dogs of 6.7±2.9 mL (P<0.05). Compared with control, CSB activation significantly decreased LV end-diastolic pressure and circulating plasma norepinephrine, normalized expression of cardiac β(1)-adrenergic receptors, β-adrenergic receptor kinase, and nitric oxide synthase and reduced interstitial fibrosis and cardiomyocyte hypertrophy. CONCLUSIONS: In dogs with advanced heart failure, CSB activation improves global LV function and partially reverses LV remodeling both globally and at cellular and molecular levels.
Sabbah et al. (Sat,) conducted a other in Advanced chronic heart failure (n=14). Bilateral carotid sinus baroreflex (CSB) activation using the Rheos System vs. No CSB activation was evaluated on Change in left ventricular ejection fraction (p=<0.05). Long-term electric activation of the carotid sinus baroreflex in dogs with advanced heart failure increased LV ejection fraction by 4.0±2.4% compared to a 2.8±1.0% reduction in controls (P<0.05).