Cardiovascular Pharmacology

Osocimab: A Novel Agent in Preventing Venous Thromboembolism Abstract: The nature of orthopedic surgery, and specifically total knee arthroplasty, lends itself to the development of venous thromboembolism given endothelial injury from the surgical procedure, promotion of an acute hypercoagulable state, and the prolonged period of immobilization after surgery promoting stasis; all factors of Virchow's triad. Current guidelines recommend the direct acting oral anticoagulants, enoxaparin, fondaparinux, and warfarin as options for venous thromboembolism prevention. However, these agents may still be prone to unacceptable bleeding risk, given they mostly target the extrinsic pathway of the clotting cascade, and have other characteristics which can be problematic for use. Investigators have determined patients with factor XI deficiency seem to be protected for thrombotic risk and seem to be devoid of bleeding sequelae. This has led to the development of osocimab, a fully humanized monoclonal G1 antibody designed specifically to functionally neutralize factor XIa. Phase 1 clinical trials have demonstrated an agent with a long half-life (∼30 days) with minimal requirement of renal elimination and hepatic metabolism. Phase 2 trials have identified that an optimal dose range, 0.6–1.2 mg/kg, as a 1-time dose preoperatively or postoperatively is effective in preventing thrombotic complications with minimal bleeding risk compared with standard of care for elective total knee arthroplasty patients. Future clinical development will be able to clearly outline the role this agent will play in the future.

Role of Stem Cell–Derived Microvesicles in Cardiovascular Disease Abstract: The role of stem cells in augmenting reparative processes in the heart after ischemic injury has been successfully demonstrated in small and large animal models. However, the outcomes of cell therapy in clinical trials have been somewhat variable, with overall effects of autologous stem cell therapies demonstrating a modest improvement in cardiac structure and function. How stem cells repair the heart after cardiac injury is still not well understood. Most recent studies suggest that adult derived stem cells act primarily through paracrine signaling to exert beneficial effects, including modulation of immune response, stimulation of new blood vessel formation, or by inducing mature myocytes to transiently reenter the cell cycle, rather than robust direct differentiation of the transplanted cells into myocytes. In addition, data from multiple laboratory results confirmed clearance of stem cells themselves within a few days still leading to functional benefits further confirming the role of paracrine signaling in augmenting cardiac reparative processes rather than direct differentiation of cells. These findings rapidly evolved the field of extracellular vesicles specifically microvesicles (MVs) as they are active hubs of autocrine, paracrine, and endocrine signaling targeting different biological processes. The beneficial effects seen after stem cell transplantation could be linked to the cardioprotective factors packaged in the MVs secreted from stem cells. Therefore, stem cell MVs provide a new avenue for the treatment of cardiovascular disease through a multitude of mechanisms including cellular communication within the stem cell niches, delivery of genetic information, regulation of the immune system in the heart, and stimulation of angiogenesis which will be discussed in this review.

Role of Lipid-Lowering Therapy in Low-Density Lipoprotein Cholesterol Goal Attainment: Focus on Patients With Acute Coronary Syndrome Abstract: Dyslipidemia is a major risk factor for cardiovascular (CV) disease, which is the leading cause of death globally. Acute coronary syndrome (ACS) is a common cause of death, accounting for nearly half of the global burden of CV mortality. Epidemiologic studies have identified low-density lipoprotein cholesterol (LDL-C) as an independent CV risk factor, and this is now the primary target for initiating and adjusting lipid-lowering therapies in most current guidelines. Evidence from pivotal studies supports the use of high-intensity statin therapy and a lower level for optimal LDL-C in secondary prevention of atherosclerotic CV disease, especially in patients with ACS undergoing percutaneous coronary intervention. However, current research has identified a gap between the target LDL-C goal attainment and target LDL-C levels recommended by the guidelines. Statins have proven benefits in the management of CV disease and are the cornerstone of lipid-lowering management in patients with ACS. Recent randomized controlled trials have also demonstrated the benefits of cholesterol absorption inhibitors and proprotein convertase subtilisin/kexin type 9 inhibitors. This review summarizes the current evidence for LDL-lowering therapy in patients with ACS, with an emphasis on the importance of LDL-C goal attainment, rapid LDL-C lowering, and duration of LDL-C–lowering therapy.

Efficacy and Safety of Non-Vitamin K Antagonist Oral Anticoagulants in Patients With Atrial Fibrillation and Chronic Kidney Disease Stage G4: A Single-Center Experience Abstract: Atrial fibrillation (AF) is associated with increased stroke and bleeding risk in patients with chronic kidney disease (CKD). Little is known about the real-life use of non-vitamin K antagonist oral anticoagulants (NOACs) in CKD stage G4. In a retrospective cohort study, we enrolled 182 consecutive AF patients with CKD stage G4 including 90 (49%) subjects on NOAC, ie, 61 on apixaban 2.5 mg bid and 29 on rivaroxaban 15 mg qd, and 92 (51%) subjects on warfarin. Thromboembolic and bleeding events were recorded during a mean follow-up of 26.3 months. There were no differences in demographic, clinical, and laboratory variables at baseline between the 2 treatment groups. During follow-up, arterial thromboembolic events occurred in 11 (12.22%) subjects on NOAC and 7 (7.61%) on warfarin, (hazard ratio [HR] 1.70; 95% CI, 0.65–4.42), with similar risk of ischemic stroke (9 [10%] vs. 7 [7.61%], P = 0.56, respectively). Major bleedings or clinically relevant nonmajor bleeding occurred in 14 (15.56%) on NOAC and 13 (14.13%) on warfarin, (HR 1.12; 95% CI, 0.53–2.39), with similar risk of gastrointestinal bleeding (HR 0.70; 95% CI, 0.20–2.47). We observed no difference in all-cause mortality related to the type of anticoagulants, but it tended to be lower in the apixaban group compared with rivaroxaban group (14.7% vs. 31%, P = 0.07), without any differences in thromboembolic and bleeding events. The study suggests that AF patients with CKD stage G4 receiving reduced-dose NOAC or warfarin have similar risk of thromboembolism and bleeding in everyday practice of a tertiary anticoagulation center.

Effect of Secondary Prevention Medication on the Prognosis in Patients With Myocardial Infarction With Nonobstructive Coronary Artery Disease Abstract: Myocardial infarction with nonobstructive coronary arteries (MINOCA) has been and remained a puzzling clinical entity. The role of secondary prevention therapy in patients with MINOCA remains unclear. This study aimed to evaluate the associations between secondary prevention medications and outcomes in patients with MINOCA. A total of 259 patients with MINOCA were consecutively enrolled. Basic information and medication of patients were assessed. We defined major adverse cardiovascular events as the primary end point and angina rehospitalization as the secondary end point. Logistic regression models were used to assess the correlation between treatment and outcomes. The proportion of statins, aspirin, clopidogrel, angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers (ACEI/ARB), and β-blocker used at admission was 88.8%, 86.9%, 84.6%, 51.7%, and 61.4%, respectively. At discharge, patients with MINOCA were less likely to be released on statins, aspirin, clopidogrel, ACEI/ARB, and β-blocker. The use of secondary prevention medications was significantly lower at 2 years of follow-up with the most significant reductions being clopidogrel 29.4%, ACEI/ARB 39.0%, and aspirin 42.3%. About 19.1% of patients with MINOCA suffered adverse events during the follow-up period. Adverse events risk decreased when statins and ACEI/ARB were used, whereas the risk of adverse events was not lower in patients with aspirin, clopidogrel, and β-blocker. In conclusion, patients with MINOCA were less likely to receive secondary prevention medications at the time of discharge and early discontinuation of medications at the time of follow-up. Statins and ACEI/ARB were the only medications substantially associated with lower adverse events; by comparison, aspirin, clopidogrel, and β-blocker seem to have no impact on prognosis.

Combination of the Phosphodiesterase Inhibitors Sildenafil and Milrinone Induces Cardioprotection With Various Conditioning Strategies Abstract: Ischemic preconditioning and postconditioning are strong measures preserving the heart against ischemia–reperfusion injury in experimental setting but are too invasive and impractical for clinical routine. The cardioprotective effects of ischemic preconditioning and postconditioning can be imitated pharmacologically, for example, with the phosphodiesterase inhibitors sildenafil and milrinone. We hypothesize that sildenafil-induced preconditioning is concentration dependent and further that a combined treatment of "nonprotective" versus "protective" concentrations of sildenafil and milrinone leads to a significant infarct size reduction. Experiments were performed on isolated hearts of male Wistar rats, randomized into 12 groups, mounted onto a Langendorff system, and perfused with Krebs–Henseleit buffer. All hearts underwent 33 minutes ischemia and 60 minutes of reperfusion. For determination of a concentration-dependent effect of sildenafil, hearts were perfused with increasing concentrations of sildenafil (0.1–1 µM) over 10 minutes before ischemia. In a second series of experiments, hearts were treated with 0.3 µM sildenafil or 1 µM milrinone as the "protective" concentrations. A higher concentration of respective drugs did not further reduce infarct size. In addition, a combination of "protective" and "nonprotective" concentrations of sildenafil and milrinone was applied. Sildenafil and milrinone in lower concentrations led to significant infarct size reduction, whereas combining both substances in cardioprotective concentrations did not enhance this effect. Sildenafil in a concentration of 0.3 µM induces myocardial protection. Furthermore, treatment with sildenafil and milrinone in lower concentrations had an equally strong cardioprotective effect regarding infarct size reduction compared with the administration of "protective" concentrations.

Impact of RAAS Blockers on Contrast-Induced Nephropathy in Patients With Renal Insufficiency: A Meta-Analysis Abstract: The effect of renin-angiotensin-aldosterone system (RAAS) blockers [angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers] on Contrast-induced nephropathy (CIN) is unclear in patients with renal insufficiency. Thus, we conduct a meta-analysis to evaluate the association between the administration of RAAS blockers and CIN in patients with renal insufficiency. We searched PubMed, EMBASE, and Cochrane Library for relevant studies published before September 2019. The primary outcome was the incidence of CIN, and the secondary outcome was the changes in serum creatinine (SCr) from baseline to postprocedure (ΔSCr). Pooled odds ratio (OR) or weighted mean difference (WMD) with their 95% confidence interval (CIs) for the CIN incidence, ΔSCr were used to calculate original data. A total of 8 studies were included in the meta-analysis. Compared with controls, ACEI/angiotensin receptor blocker increased the risk of CIN (OR = 1.61, 95% CI 1.14–2.28, I2 = 30%; P = 0.007), whereas this association was not significant in Chinese patients (OR = 1.07, 95% CI 0.65–1.77, I2 = 19%, P = 0.79). The total weighted mean differences of the ΔSCr were 0.06 mg/dL (95% CI: 0.01–0.11, I2 = 82%; P = 0.03). Administration of RAAS blockers in patients with renal insufficiency was associated with a significantly higher incidence of CIN, whereas it did not show a significant effect on Chinese patients.

Effects of Carvedilol and Thyroid Hormones Co-administration on Apoptotic and Survival Proteins in the Heart After Acute Myocardial Infarction Abstract: Cellular death and survival signaling plays a key role in the progress of adverse cardiac remodeling after acute myocardial infarction (AMI). Therapeutic strategies, such as co-treatment with beta-blocker carvedilol and thyroid hormones (THs), give rise to new approaches that can sustain the cellular homeostasis after AMI. Therefore, we sought to investigate the effects of carvedilol and TH co-administration on apoptosis and survival proteins and on cardiac remodeling after AMI. Male Wistar rats were distributed in 5 groups as follows: sham-operated group (SHAM), infarcted group (MI), infarcted plus carvedilol group (MI+C), infarcted plus TH group (MI+TH), and infarcted plus carvedilol and TH co-treatment group (MI+C+TH). Echocardiographic analysis was performed, and hearts were collected for western blot evaluation. The MI group presented systolic posterior wall thickness loss, an increase in the wall tension index, and an increase in atrial natriuretic peptide tissue levels than the SHAM group. However, in the MI+C+TH group, these parameters were equally to the SHAM group. Moreover, whereas the MI group showed Bax protein expression elevated in relation to the SHAM group, the MI+C+TH group presented Bax reduction and also Akt activation compared with the MI group. In addition, the MI+TH group revealed beta-1 adrenergic receptor (β1AR) upregulation compared with the MI and MI+C groups, whereas the MI+C+TH group presented lower levels of β1AR in relation to the SHAM and MI+TH groups. In conclusion, we suggest that carvedilol and TH co-administration may mediate its cardioprotective effects against adverse cardiac remodeling post-AMI through the Bax reduction, Akt activation, and β1AR decrease.

Dexamethasone Does Not Inhibit Treadmill Training–Induced Angiogenesis in Myocardium: Role of MicroRNA-126 Pathway Abstract: Dexamethasone (DEX) has important anti-inflammatory activities; however, it induces hypertension and skeletal muscle microcirculation rarefaction. Nevertheless, nothing is known about DEX outcomes on cardiac microcirculation. By contrast, exercise training prevents skeletal and cardiac microvessel loss because of microRNA expression and a better balance between their related angiogenic and apoptotic proteins in spontaneously hypertensive rats. The purpose of this study was to investigate whether DEX and/or exercise training could induce microRNA alterations leading to cardiac angiogenesis or microvascular rarefaction. Animals performed 8 weeks of exercise training and were treated with DEX (50 μg/kg per day, subcutaneously) for 14 days. Cardiovascular parameters were measured, and the left ventricle muscle was collected for analyses. DEX treatment increased arterial pressure and did not cause cardiac microcirculation rarefaction. Treadmill training prevented the DEX-induced increase in arterial pressure. In addition, training, regardless of DEX treatment, increased microRNA-126 expression, phospho-protein kinase B/protein kinase B, and endothelial nitric oxide synthase levels associated with cardiac angiogenesis. In conclusion, this study suggests, for the first time, that treadmill training induces myocardial angiogenesis because of angiogenic pathway improvement associated with an increase in microRNA-126. Furthermore, DEX, per se, did not cause capillary density alterations and did not attenuate cardiac angiogenesis induced by training.

Anticontractile Effect of Perivascular Adipose Tissue But Not of Endothelium Is Enhanced by Hydrogen Sulfide Stimulation in Hypertensive Pregnant Rat Aortae Abstract: Perivascular adipose tissue (PVAT) modulates the vascular tone. Hydrogen sulfide (H2S) is synthetized by cystathionine gamma-lyase (CSE) in brown PVAT. Modulation of vascular contractility by H2S is, in part, adenosine triphosphate (ATP)-sensitive potassium channels dependent. However, the role of PVAT-derived H2S in hypertensive pregnancy (HTN-Preg) is unclear. Therefore, we aimed to examine the involvement of H2S in the anticontractile effect of PVAT in aortae from normotensive and hypertensive pregnant rats. To this end, phenylephrine-induced contractions in the presence and absence of PVAT and endothelium in aortae from normotensive pregnant (Norm-Preg) and HTN-Preg rats were investigated. Maternal blood pressure, fetal-placental parameters, angiogenesis-related biomarkers, and H2S levels were also assessed. We found that circulating H2S is elevated in hypertensive pregnancy associated with angiogenic imbalance, fetal and placental growth restrictions, which revealed that there is H2S pathway activation. Moreover, under stimulated H2S formation PVAT, but not endothelium, reduced phenylephrine-induced contractions in aortae from HTN-Preg rats. Also, H2S synthesis inhibitor abolished anticontractile effects of PVAT and endothelium. Furthermore, anticontractile effect of PVAT, but not of endothelium, was eliminated by ATP-sensitive potassium channels blocker. In accordance, increases in H2S levels in PVAT and placenta, but not in aortae without PVAT, were also observed. In conclusion, anticontractile effect of PVAT is lost, at least in part, in HTN-Preg aortae and PVAT effect is ATP-sensitive potassium channels dependent in normotensive and hypertensive pregnant rat aortae. PVAT but not endothelium is responsive to the H2S stimulation in hypertensive pregnant rat aortae, implying a key role for PVAT-derived H2S under endothelial dysfunction.

#

Medicine by Alexandros G. Sfakianakis,Anapafseos 5 Agios Nikolaos 72100 Crete Greece,00302841026182,00306932607174,alsfakia@gmail.com,

Telephone consultation 11855 int 1193,