Outcomes of Surgical Bioprosthetic Aortic Valve Replacement in Patients Aged ≤65 and >65 Years.

Background: Implantation of a bioprosthetic valve is a reasonable choice for patients aged > 65 years. For middle-aged patients there is less certainty about whether a mechanical or bioprosthetic valve is best.

Methods: The Pericardial Surgical Aortic Valve Replacement (PERIGON) Pivotal Trial is evaluating the safety and efficacy of the Avalus bioprosthesis (Medtronic).

Biphasic effect of metformin on human cardiac energetics.

Metformin is the first-line medication for treatment of type 2 diabetes and has been shown to reduce heart damage and death. However, mechanisms by which metformin protects human heart remain debated. The aim of the study was to evaluate the cardioprotective effect of metformin on cardiomyocytes derived from human-induced pluripotent stem cells (hiPSC-CMs) and mitochondria isolated from human cardiac tissue.

Addiction Management in Hospitalized Patients With Intravenous Drug Use-Associated Infective Endocarditis.

Background: Infections related to intravenous drug use and opioid use disorders (OUDs) are increasing nationwide. Endocarditis is a recognized complication of intravenous drug use, and inpatient treatment typically focuses on infection management without attention to underlying addiction.

Objective: A comprehensive intervention for inpatients with infective endocarditis and intravenous drug use was implemented by a multidisciplinary team at a large midwestern hospital.

Characterizing Recurrence Following Hybrid Ablation in Patients With Persistent Atrial Fibrillation.

Purpose: It is widely accepted that atrial fibrillation (AF) accounts for half of arrhythmia recurrences following endocardial catheter ablation of AF. An epicardial-endocardial approach (hybrid) has emerged as an alternative to endocardial ablation alone for the treatment of AF, yet recurrence after a hybrid procedure has not been well characterized. This retrospective study is aimed at characterizing recurrence following hybrid ablation for patients with persistent AF.

Noninvasive biomarker-based risk stratification for development of new onset atrial fibrillation after coronary artery bypass surgery.

Background: Postoperative atrial fibrillation (PoAF) is a common complication after cardiac surgery. A pre-existing atrial substrate appears to be important in postoperative development of dysrhythmia, but its preoperative estimation is challenging. We tested the hypothesis that a combination of clinical predictors, noninvasive surrogate markers for atrial fibrosis defining abnormal left atrial (LA) mechanics, and biomarkers of collagen turnover is superior to clinical predictors alone in identifying patients at-risk for PoAF.

Chamber-specific differences in human cardiac fibroblast proliferation and responsiveness toward simvastatin.

Fibroblasts, the most abundant cells in the heart, contribute to cardiac fibrosis, the substrate for the development of arrythmogenesis, and therefore are potential targets for preventing arrhythmic cardiac remodeling. A chamber-specific difference in the responsiveness of fibroblasts from the atria and ventricles toward cytokine and growth factors has been described in animal models, but it is unclear whether similar differences exist in human cardiac fibroblasts (HCFs) and whether drugs affect their proliferation differentially. Using cardiac fibroblasts from humans, differences between atrial and ventricular fibroblasts in serum-induced proliferation, DNA synthesis, cell cycle progression, cyclin gene expression, and their inhibition by simvastatin were determined.

Selective downregulation of mitochondrial electron transport chain activity and increased oxidative stress in human atrial fibrillation.

Mitochondria are critical for maintaining normal cardiac function, and a deficit in mitochondrial energetics can lead to the development of the substrate that promotes atrial fibrillation (AF) and its progression. However, the link between mitochondrial dysfunction and AF in humans is still not fully defined. The aim of this study was to elucidate differences in the functional activity of mitochondrial oxidative phosphorylation (OXPHOS) complexes and oxidative stress in right atrial tissue from patients without (non-AF) and with AF (AF) who were undergoing open-heart surgery and were not significantly different for age, sex, major comorbidities, and medications.

Circulating Biomarkers Predictive of Postoperative Atrial Fibrillation.

Postoperative atrial fibrillation (PoAF), a common complication of cardiac surgery, contributes significantly to morbidity, mortality, and increasing healthcare costs. Despite advances in surgical and medical management, the overall incidence of PoAF has not changed significantly, partly because of the limited understanding of mechanisms underlying acute surgery-related factors, such as myocardial injury, inflammation, sympathetic activation, and oxidative stress, which play an important role in the initiation of PoAF, whereas a preexisting atrial substrate appears to be more important in the maintenance of this dysrhythmia. Thus, in a majority of patients, PoAF becomes a manifestation of an underlying arrhythmogenic substrate that is unmasked after acute surgical stress.

Pharmacological strategies for prevention of postoperative atrial fibrillation.

Atrial fibrillation (AF) complicating cardiac surgery continues to be a major problem that increases the postoperative risk of stroke, myocardial infarction, heart failure and costs and can affect long-term survival. The incidence of AF after surgery has not significantly changed over the last two decades, despite improvement in medical and surgical techniques. The mechanism and pathophysiology underlying postoperative AF (PoAF) is incompletely understood and results from a combination of acute and chronic factors, superimposed on an underlying abnormal atrial substrate with increased interstitial fibrosis.

Cost-effectiveness of the convergent procedure and catheter ablation for non-paroxysmal atrial fibrillation.

Objective: Patients with persistent or longstanding atrial fibrillation have modest success achieving sinus rhythm with catheter ablation or rhythm control medications. Their high risk of stroke, bleed, and heart failure leads to significant morbidity and health care costs. The convergent procedure has been shown to be successful in this population, with 80% of patients in sinus rhythm after 1 year.

Left atrial laceration with epicardial ligation device.

Many new devices and techniques are being developed to attempt a reduction in embolic stroke risk for patients with atrial fibrillation who are either unable or unwilling to maintain long-term anticoagulation. One of these new devices (LARIAT®, SentreHEART Inc., Redwood City, California, USA) employs delivery of an epicardial suture to ligate the left atrial appendage after percutaneous pericardial and transseptal access.

Exit vs. entrance block testing for cardiac lesion assessment.

Cardiac lesions are created to act as barriers which prohibit the transmission of cardiac myocyte contractile activity from one side of the lesion to the other. Testing for conduction block is the main way to acutely confirm the effectiveness of this therapy. There are two general methods used to test for conduction block.

Positive heparin-platelet factor 4 antibody complex and cardiac surgical outcomes.

Background: Given the large number of patients undergoing cardiac operations annually, it is important to identify populations at high risk for adverse outcomes. This observational study was conducted to determine the incidence of preoperative heparin-platelet factor 4 (HPF4) antibodies and to assess the associated risk of postoperative adverse outcomes in a nonselected cardiac surgery patient population.

Methods: Between March 2002 and December 2004, 1114 (92%) of 1209 patients undergoing cardiac surgery with heparin were tested in an unselected manner for HPF4 antibodies.

Intraoperative effects of the coapsys annuloplasty system in a randomized evaluation (RESTOR-MV) of functional ischemic mitral regurgitation.

Background: Functional ischemic mitral regurgitation (MR) frequently arises after myocardial infarction; it is characterized by annular enlargement or lateral displacement of the subvalvular apparatus. Coapsys is a ventricular-annular remodeling device designed to treat functional ischemic MR; it does not require cardiopulmonary bypass. Initial intraoperative results of the RESTOR-MV randomized clinical trial are presented.

Radiofrequency ablation of atrial fibrillation during mitral valve surgery.

Twenty-three patients underwent endocardial radiofrequency ablation of atrial fibrillation (AF) during mitral valve procedures with a previously described left atrial lesion pattern. A temperature-controlled 7-coil surgical probe delivered 60-second lesions at 80 degrees C. The left atrial appendage was oversewn after ablation.

Validation of a left atrial lesion pattern for intraoperative ablation of atrial fibrillation.

Background: Evidence that atrial fibrillation may begin in early stages from triggers or reentry circuits primarily in the left atrium suggests that the entire Maze 3 lesion pattern may be unnecessary. In the present study we describe a new left atrial lesion pattern for intraoperative linear ablation of chronic atrial fibrillation.

Methods: Endocardial radiofrequency ablation was performed on 12 dogs with chronic atrial fibrillation.