Atrial fibrillation: Epigenetic aspects and role of sodium-glucose cotransporter 2 inhibitors

Atrial fibrillation (AF) is the most frequent arrhythmia and is associated with substantial morbidity and mortality. Pathophysiological aspects consist in the activation of pro-fibrotic signaling and Ca²⁺ handling abnormalities at atrial level. Structural and electrical remodeling creates a substrate for AF by triggering conduction abnormalities and cardiac arrhythmias. The care of AF patients focuses predominantly on anticoagulation, symptoms control and the management of risk factors and comorbidities. The goal of AF therapy points to restore sinus rhythm, re-establish atrioventricular synchrony and improve atrial contribution to the stroke volume. New layer of information to better comprehend AF pathophysiology, and identify targets for novel pharmacological interventions consists of the epigenetic phenomena including, among others, DNA methylation, histone modifications and noncoding RNAs. Moreover, the benefits of sodium-glucose cotransporter 2 inhibitors (SGLT2i) in diabetic and non-diabetic patients at cardiovascular risk as well as emerging evidence on the ability of SGLT2i to modify epigenetic signature in cardiovascular diseases provide a solid background to investigate a possible role of this drug class in the onset and progression of AF. In this review, following a summary of pathophysiology and management, epigenetic mechanisms in AF and the potential of sodium-glucose SGLT2i in AF patients are discussed.

Sacubitril/valsartan in an experimental model of heart failure with preserved ejection fraction

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Ministry for Education, University and Research

Introduction

The majority of elderly patients with heart failure has a preserved ejection fraction (HFpEF) that constitutes a syndrome characterized by frequent hospitalizations and high mortality. Despite the growing social burden of HFpEF, the comprehension of its pathophysiology is incomplete, and treatment remains largely undefined. Aging itself may contribute independently to deterioration of diastolic function.

Methods

18-month old female Fischer 344 rats were treated with oral administration of either sacubitril/valsartan (60 mg/kg/die, 1:1 ratio) or valsartan alone (30 mg/kg/die) for 12 weeks. Tail-cuff method was used to monitor blood pressure weekly. Echocardiography and left ventricle catheterization were employed to assess systolic and diastolic function, at baseline, and before sacrifice. Cardiac tissue was used for molecular biology and histochemistry assays.

Results

Tail-cuff analysis indicated a comparable decrease in blood pressure between treatments. Hypertrophy also showed a significant reduction with both treatments. On the contrary, myocardial function analysis demonstrated that no treatment was efficacy on diastolic dysfunction. The lack of improvement of cardiac function could be attributed to the inability of the treatments to counteract the accumulation of fibrotic tissue in the left ventricle, which, in turn, is attributable to the failure to reduce the inflammatory process and oxidative stress, and to the inability to modulate angiotensin II pathway.

Conclusion

Our results evidenced that both sacubitril/valsartan or valsartan treatment was able to improve diastolic function and pro-fibrotic remodeling, partly due to a lack of effect on classical and non-classical pathways of angiotensin II.

Vascularized fibula free flap for implant rehabilitation in the case of extreme atrophy

The skeletal reconstruction in cases of extreme atrophy like a class VI Cawood classification can be carried out using free bone flaps. They represent a valid option for preprosthetic rehabilitation of atrophic maxillas. Over the last 5 years, the use of vascularized bone transplants, aimed at implant-prosthetic rehabilitation, has become a practice, which has gradually found the right indications and the range of applications, which are now widely acknowledged. The key to success in the use of free flaps lies in the identification of the correct indications for use, in meticulous programming and the particular motivation that this type of patient has for reacquiring optimum masticatory functions. The final prosthetic implant rehabilitation must be prosthetically guided and an accurate preoperative planning is of fundamental importance for restoring masticatory functions and esthetic harmony to the patient through a fixed prosthesis. The authors present a case of a rehabilitation of an extreme maxillary and mandibular atrophy.

Reconstruction of the anterior floor of the mouth using a peroneal perforator free flap. A case report

Personal experience is presented concerning a case in which reconstruction of the anterior floor of the mouth was carried out using a fascio-cutaneous free flap harvested from the lateral part of the leg; the flap pedicle is represented by perforating vessels originating from the peroneal vascular axis.

Iliac crest free flap in oromandibular reconstruction. 13 cases study

Oromandibular reconstruction following oncological resection is particularly challenging. In this past decade, great improvements have been made, in functional and aesthetic terms, following the introduction of composite free flaps. By means of this reconstructive technique, it is, in fact, possible to restore mandibular continuity, and, consequently, the morphology of the lower third of the face; rehabilitate mastication through osteointegrated implants, and optimise the reconstruction of soft tissue, employing the fascio-cutaneous or muscular portion of these flaps. Between January 1995 and January 2001, 70 oromandibular reconstructions employing osseous free flaps were performed in the Department of Maxillo-Facial Surgery of the Ospedale Maggiore in Parma, and in 13 of these the iliac crest free flap was used. Personal experience is described regarding the indications and use of this flap.

[The surgical verification of the periodontal probe and endoral radiography in assessing the bone substance loss in periodontal disease. A proposal for optimizing the methods]

It is difficult to compare levels of bone loss in periodontal disease measured by periodontal probe and X-ray and to verify them versus surgical techniques. In fact, there are relatively few published reports on the subject. To this purpose the Authors describe their personal experience using plates equipped with guide tracks and center-film boxes with personalized bites. The suitability of the two methods (probe, intraoral X-ray) to determine levels of bone loss similar to those revealed by surgical verification was assessed on the basis of an analysis of the respective bone loss in 44 sites surrounding 19 dental elements. This method, which is accurate but time-consuming, demonstrated an broadly analogous underestimate (approx. 20%) using both preoperative probe and X-ray techniques in comparison to the true level of bone loss measured during surgery.