The incidence of heart failure (HF) continues to increase, along with its associated morbidity, mortality, and cost. Novel therapeutic options have been proposed to address the needs of especially the patients who remain symptomatic despite optimal medical therapy. A number of factors lead to ongoing symptoms in patients with chronic heart failure (HF), including persistent abnormalities in myocardial function, neurohormonal dysregulation, and of the peripheral vascular system.~The Phase 3 VICTORIA trial examined the efficacy of Vericiguat, a novel oral soluble guanylate cyclase (sGC) stimulator in patients with HF and reduced ejection fraction (HFrEF). Vericiguat enhances the cyclic guanosine monophosphate (GMP) pathway by directly stimulating soluble guanylate cyclase independent of nitric oxide (NO). The VICTORIA study showed that patients who received Vericiguat 2.5 mg once daily up-titrated to 10 mg daily had a lower incidence of the primary endpoint of cardiovascular death or first HF hospitalization compared to placebo 1.~Determining the exact mechanism, or the respective contribution of different mechanisms, through which Vericiguat improves outcomes in HFrEF may allow for better tailoring of its use to individual patients. The preliminary results of an echocardiography sub-study indicate that there was no significant difference in the change of left ventricular ejection fraction (LVEF) between baseline and study end among patients assigned to the active drug vs placebo. We hypothesize that the beneficial effects of Vericiguat in HF may not be linked to improvement in myocardial contractility, but rather to the effects of sGC stimulation on the peripheral vasculature. This was not directly tested in VICTORIA.~Studies from our group 2, 3 and others 4, 5 have collectively identified a marked reduction in vascular function, as determined by flow-mediated vasodilation (FMD) testing, in patients with HFrEF despite optimized pharmacotherapy, indicative of a pervasive, disease-related reduction in endothelial health. Endothelial dysfunction is characterized by NO dysregulation, inflammation, and oxidative stress. These factors impair the capacity of the vascular endothelium to perform its numerous functions including regulation of vascular tone and inflammatory processes. Importantly, endothelial dysfunction is also associated with reduced quality of life 6 and decreased physical capacity 7, 8 in patients with HFrEF. These studies suggest that the consequences of vascular dysfunction are far-reaching and support the concept that interventions targeting the peripheral vasculature to induce systemic effects could prove beneficial in cardiovascular disease. This is particularly relevant given the known relationship between endothelial dysfunction and mortality risk in patients with HFrEF 9, 10. Improvement in peripheral vascular function in patients with HFrEF would in turn lead to improved physical capacity and health-related quality of life (hrQOL).~Preclinical studies provide evidence of sGC stimulation favorably affecting peripheral vascular function. In a rat model of HF, treatment with Ataciguat normalized endothelial function, improved sensitivity to NO, and reduced platelet activation 11. However, the impact of Vericiguat on vascular health has not been evaluated in human HF. A recent study also examined the effect of Vericiguat on inflammation and oxidative stress in HF 12. After 12 weeks of Vericiguat therapy, high sensitivity CRP (hsCRP) decreased significantly, and the probability of hsCRP value being ≤3.0 mg/L at the end of the study was higher in patients treated with Vericiguat compared to placebo. Although the impact of Vericiguat on upstream, inflammatory cytokines such as IL-1β and IL-18 have not been determined, there is strong evidence supporting elevation of these biomarkers that reflect NRLP3 inflammasome activation in patients with HFrEF13, 14. Given the recent success in clinical trials targeting the inflammasome in heart failure 15 and recent evidence for the efficacy of sGC stimulation to mitigate NLRP3 inflammasome activity in other organ systems 16, there is strong rationale for the expectation that Vericiguat may favorably impact both upstream (IL-1β, IL-18, TNF-α and IL-6) and downstream (hsCRP) inflammatory biomarkers. Importantly, an inverse correlation between biomarkers of inflammation and endothelial function has been observed in other patient groups 13, supporting the concept that Vericiguat treatment may result in greater improvements in vascular function in those individuals who experience the largest reductions in vascular inflammation.
The concept that direct stimulation of soluble guanylate cyclase (sGC) could be a particularly effective approach to increase cyclic guanosine monophosphate (cGMP) in conditions of increased inflammation/oxidative stress, endothelial dysfunction, and reduced nitric oxide (NO) bioavailability. Thus, the aim of the proposed study is to examine the effect of Vericiguat on peripheral vascular function, inflammatory status, and patient health status. The study also aims to identify patients who are particularly likely to benefit from Vericiguat treatment and predict that these patients will be defined by baseline peripheral vascular dysfunction and high inflammatory state.