BACKGROUND: Coronary artery disease is the leading cause of death worldwide. It imposes an enormous symptomatic burden on patients, leaving many with residual disease despite optimal procedural therapy and up to one-thirds with debilitating angina amenable neither to procedures, nor to current pharmacological options. Semaglutide (SEM), a GLP-1 (glucagon-like peptide 1) agonist originally approved for management of diabetes, has garnered substantial attention for its capacity to attenuate cardiovascular risk. Although subgroup analyses in patients indicate promise, studies explicitly designed to isolate the impact of SEM on the sequelae of coronary artery disease, independently of comorbid diabetes or obesity, are lacking. METHODS: Yorkshire swine (n=17) underwent placement of an ameroid constrictor around the left circumflex coronary artery to induce coronary artery disease. Oral SEM was initiated postoperatively at 1.5 mg and scaled up in 2 weeks to 3 mg in treatment animals (n=8) for a total of 5 weeks, while control animals (n=9) received no drug. All then underwent myocardial harvest with acquisition of perfusion and functional data using microsphere injection and pressure-volume loop catheterization. Immunoblotting, immunohistochemistry, and immunofluorescence were performed on the most ischemic myocardial segments for mechanistic elucidation. RESULTS: SEM animals exhibited improved left ventricular ejection fraction, both at rest and during rapid myocardial pacing (both P <0.03), accompanied by increased perfusion to the most ischemic myocardial region at rest and during rapid pacing (both P <0.03); reduced perivascular and interstitial fibrosis (both P <0.03); and apoptosis ( P =0.008). These changes were associated with increased activation of the endothelial-protective AMPK (AMP-activated protein kinase) pathway ( P =0.005), coupled with downstream increases in eNOS (endothelial NO synthase; P =0.014). CONCLUSIONS: This study reveals the capacity of oral SEM to augment cardiac function in the chronically ischemic heart in a highly translational large animal model, likely through AMPK-mediated improvement in endothelial function and perfusion to the ischemic myocardium.

There is a significant body of literature to suggest that coronary artery disease (CAD) is a highly sex-specific disease. The study of sex-specific therapeutics and sex-specific responses to treatment for CAD remains underreported in the literature. Sodium-glucose transporter 2 (SGLT2) inhibitors are of growing interest in the treatment of ischemic heart disease and heart failure; however, the sex-specific response to SGLT2 inhibitors is unknown. We studied an SGLT2 inhibitor, canagliflozin, in a swine model of metabolic syndrome (MS) and chronic myocardial ischemia with emphasis on the sex-specific outcomes. Yorkshire swine (n = 21) were obtained at 6 weeks of age and fed a high-fat diet to induce MS. Left thoracotomy was performed on all swine at 11 weeks of age for the placement of an ameroid constrictor to model chronic myocardial ischemia. Swine recovered for two weeks, then were assigned to either the drug group, CAN 300 mg daily group (M = 5, F = 5), or the control group (CON, M = 5, F = 6). Both groups received 5 weeks of therapy. After completion of therapy, swine underwent functional assessment and terminal harvest. The male animals treated with CAN (CAN-M) had significant increases in stroke volume and cardiac output (p = 0.047, p < 0.001) compared to control males (CON-M), which were not seen in females treated with CAN (CAN-F) compared to control females (CON-F). Effective arterial elastance was decreased in CAN-M compared to CON-M. The CAN-F group had a significant increase in ischemic myocardial capillary density compared to CON-F (p = 0.04). There was no difference in capillary density between the CAN-M and CON-M groups. CAN treatment resulted in sex-specific changes in angiogenesis and myocardial function. The CAN-M group had significant improvements in cardiac function based on afterload reduction, stroke volume, and increased cardiac output not seen in the CAN-F group. The CAN-F group had increased ischemic myocardial capillary density. These findings provide a foundation for further investigation of the sex-specific effects of SGLT-2 inhibitors in humans.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is initiated by the viral spike proteins, which are key structural components that mediate host cell binding and entry and alter downstream signaling through multiple interactions with endothelial surface receptors. Endothelial dysfunction is a central consequence of COVID-19, contributing to vascular inflammation, barrier disruption, thrombosis, and multi-organ injury affecting the pulmonary, cardiovascular, cerebral, and renal systems. Emerging evidence demonstrates that spike protein-mediated effects, independent of productive viral infection, disrupt endothelial homeostasis through angiotensin-converting enzyme 2 (ACE2) dysregulation, integrin engagement, altered calcium signaling, junctional protein remodeling, oxidative stress, and pro-inflammatory and pro-apoptotic pathways. This review is intentionally focused on spike (S) protein-driven mechanisms of endothelial dysfunction; pathogenic vascular effects attributed to other SARS-CoV-2 structural proteins, including the nucleocapsid (N) protein, are beyond the scope of this discussion. In this review, we synthesize current experimental and translational data detailing the molecular mechanisms by which the SARS-CoV-2 spike protein drives endothelial dysfunction across multiple organ systems and discuss potential therapeutic strategies aimed at preserving endothelial integrity in acute COVID-19 and its long-term vascular sequela.