A case of electromagnetic interference between HeartMate 3 LVAD and implantable cardioverter defibrillator.

Implantable cardioverter defibrillators (ICDs) have been shown to have a significant benefit in reducing sudden cardiac death (SCD) in patients with systolic heart failure. Additionally, cardiac devices as a bridge to transplant or destination therapy are often used in patients with end-stage systolic heart failure. As a result, most patients with left ventricular assist devices (LVADs) also have an ICD.

Non-pulmonary vein mediated atrial fibrillation: A novel sub-phenotype.

Background: Atrial fibrillation (AF) is a mechanistically heterogeneous disorder, and the ability to identify sub-phenotypes ("endophenotypes") of AF would assist in the delivery of personalized medicine. We used the clinical response to pulmonary vein isolation (PVI) to identify a sub-group of patients with non-PV mediated AF and sought to define the clinical associations.

Methods: Subjects enrolled in the Vanderbilt AF Ablation Registry who underwent a repeat AF ablation due to arrhythmia recurrence were analyzed on the basis of PV reconnection.

Genetic Risk Prediction of Atrial Fibrillation.

Background: Atrial fibrillation (AF) has a substantial genetic basis. Identification of individuals at greatest AF risk could minimize the incidence of cardioembolic stroke.

Methods: To determine whether genetic data can stratify risk for development of AF, we examined associations between AF genetic risk scores and incident AF in 5 prospective studies comprising 18 919 individuals of European ancestry.

Evaluation of a Prediction Model for the Development of Atrial Fibrillation in a Repository of Electronic Medical Records.

Importance: Atrial fibrillation (AF) contributes to substantial morbidity, mortality, and health care expenditures. Accurate prediction of incident AF would enhance AF management and potentially improve patient outcomes.

Objective: To validate the AF risk prediction model originally developed by the Cohorts for Heart and Aging Research in Genomic Epidemiology-Atrial Fibrillation (CHARGE-AF) investigators using a large repository of electronic medical records (EMRs).

Efficacy of a Bio-Absorbable Antibacterial Envelope to Prevent Cardiac Implantable Electronic Device Infections in High-Risk Subjects.

Introduction: Cardiac implantable electronic device (CIED) infections are potentially preventable complications associated with high morbidity, mortality, and cost. A recently developed bio-absorbable antibacterial envelope (TYRX™-A) might prevent CIED infections in high-risk subjects. However, data regarding safety and efficacy have not been published.

Genetic and clinical risk prediction model for postoperative atrial fibrillation.

Background: Postoperative atrial fibrillation (PoAF) is common after coronary artery bypass grafting. We previously showed that atrial fibrillation susceptibility single nucleotide polymorphisms (SNPs) at the chromosome 4q25 locus are associated with PoAF. Here, we tested the hypothesis that a combined clinical and genetic model incorporating atrial fibrillation risk SNPs would be superior to a clinical-only model.

Improved understanding of the pathophysiology of atrial fibrillation through the lens of discrete pathological pathways.

Atrial fibrillation (AF) is a common disorder with a complex and incompletely understood pathophysiology. Genetic approaches to understanding the pathophysiology of AF have led to the identification of several biological pathways important in the pathogenesis of the arrhythmia. These include pathways important for cardiac development, generation and propagation of atrial electrical impulses, and atrial remodeling and fibrosis.

A genome-wide association study to identify genomic modulators of rate control therapy in patients with atrial fibrillation.

For many patients with atrial fibrillation, ventricular rate control with atrioventricular (AV) nodal blockers is considered first-line therapy, although response to treatment is highly variable. Using an extreme phenotype of failure of rate control necessitating AV nodal ablation and pacemaker implantation, we conducted a genome-wide association study (GWAS) to identify genomic modulators of rate control therapy. Cases included 95 patients who failed rate control therapy.

A common variant on chromosome 4q25 is associated with prolonged PR interval in subjects with and without atrial fibrillation.

Single nucleotide polymorphisms (SNPs) at chromosome 4q25 (near PITX2) are strongly associated with atrial fibrillation (AF). We assessed whether a 4q25-tagging SNP (rs2200733) is associated with PR interval duration in patients with lone and typical AF and controls. Patients with lone (n = 169) and typical (n = 269) AF enrolled in the Vanderbilt AF registry and controls (n = 1,403) derived from the Vanderbilt DNA Biobank were studied.

Comparative outcomes of transvenous extraction of sprint fidelis and riata defibrillator leads: a single center experience.

Introduction: The FDA has issued class I advisories for Medtronic Sprint Fidelis(®) and St. Jude Medical Riata(TM) ICD lead families. Transvenous Riata(TM) ICD lead extraction is typically considered higher risk than Fidelis(®) extraction, based on longer duration from implant, presence of externalized conductors and lack of silicone backfill in the SVC and RV coils.

Use of an antibacterial envelope is associated with reduced cardiac implantable electronic device infections in high-risk patients.

Introduction: The incidence of cardiac implantable electronic device (CIED) infections has risen rapidly since 2004. A commercially available minocycline and rifampin impregnated antibacterial envelope has been associated with a low CIED infection rate. We performed a retrospective cohort study analyzing CIED infection rates in patients receiving an antibacterial envelope.

Genetic variation at the 9p21 locus predicts angiographic coronary artery disease prevalence but not extent and has clinical utility.

Background: Variants at the 9p21 locus have been associated with coronary heart disease, but their precise disease phenotype and utility for clinical risk assessment are uncertain.

Methods: Consenting patients with early-onset angiographic coronary artery disease (CAD) (n = 1,011) were compared with matched subjects (n = 545) free of angiographic disease and with a random population sample (n = 565). Cases and controls were genotyped for 4 variants, and ORs for angio-CAD were determined.

Multiple-polymorphism associations of 7 matrix metalloproteinase and tissue inhibitor metalloproteinase genes with myocardial infarction and angiographic coronary artery disease.

Background: Single nucleotide polymorphisms (SNPs) in matrix metalloproteinase (MMP) genes may be associated with myocardial infarction (MI) and coronary artery disease (CAD), but studies of multiple MMP genes and their tissue inhibitors (TIMPs) are scarce. Furthermore, differentiation of predictive ability by end point (MI vs CAD) has not been addressed. This study evaluated the association with MI of SNPs in genes encoding MMPs 1, 2, 3, and 9 and TIMPs 1, 2, and 3.

Multiple less common genetic variants explain the association of the cholesteryl ester transfer protein gene with coronary artery disease.

Objectives: The objective of this study was to identify associations of the cholesteryl ester transfer protein (CETP) gene with coronary artery disease (CAD) with tagging (t) single nucleotide polymorphisms (SNPs) chosen to optimally account for intra-genic variation.

Background: The CETP gene plays a critical role in lipoprotein metabolism, but the common and well-studied TaqIB variant is inconsistently predictive of CAD.

Methods: From a deoxyribonucleic acid bank of 10,020 individuals, nondiabetic nonsmoking patients (n = 4,811) with angiographically defined, clinically significant CAD (> or =70% stenosis) or normal coronaries were genotyped for 11 CETP tSNPs.

Genotypes of the cytochrome p450 isoform, CYP2C9, and the vitamin K epoxide reductase complex subunit 1 conjointly determine stable warfarin dose: a prospective study.

Background: Warfarin has a narrow therapeutic range and wide inter-individual dosing requirements that may be related to functional variants of genes affecting warfarin metabolism (i.e., CYP2C9) and activity (i.

Lipoprotein-associated phospholipase A2 independently predicts the angiographic diagnosis of coronary artery disease and coronary death.

Background: Whereas C-reactive protein (CRP) is a nonspecific marker of coronary artery disease (CAD) and cardiovascular (CV) events, Lp-PLA2 may be a nonvariable inflammatory biomarker. We evaluated the independent association of lipoprotein-associated phospholipase A2 (Lp-PLA2) to angiographic CAD and CV events adjusting for standard factors, lipids, and CRP.

Methods: Lipoprotein-associated phospholipase A2 (PLAC test, diaDexus, Inc, San Francisco, CA) and CRP were measured from samples donated by consecutive consenting patients (N = 1493) enrolled in the registry of the Intermountain Heart Collaborative Study.

High-resolution characterization of linkage disequilibrium structure and selection of tagging single nucleotide polymorphisms: application to the cholesteryl ester transfer protein gene.

Full characterization of intragenic variation may improve candidate gene associations. This study selected tagging (t) single nucleotide polymorphisms (SNPs) to comprehensively represent genetic variability in the cholesteryl ester transfer protein (CETP) gene. Nineteen SNPs were identified in 50 unrelated individuals in the SNP discovery phase, and 13 intronic SNPs were added from the literature.

The role of a common adenosine monophosphate deaminase (AMPD)-1 polymorphism in outcomes of ischemic and nonischemic heart failure.

Background: A common variant of the adenosine monophosphate deaminase (AMPD)-1 gene (C34T) results in enzymatic inactivity and may increase adenosine in cardiac muscle and confer cardioprotection through ischemic preconditioning.

Methods And Results: We hypothesized that AMPD1 carriers with ischemic heart failure (HF) in the Beta-Blocker Evaluation of Survival Trial (BEST) might have a relative survival advantage. Patients (n = 1038, 20% black) with ischemic (58%) and nonischemic (42%) HF were followed for an average of 2.

Toll-like receptor 4 gene Asp299Gly polymorphism is associated with reductions in vascular inflammation, angiographic coronary artery disease, and clinical diabetes.

Background: Coronary artery disease (CAD) and, increasingly, diabetes are recognized as having an inflammatory basis. Membrane toll-like receptors (TLRs) activate signaling pathways that up-regulate inflammation. We evaluated whether the Asp299Gly polymorphism in the TLR4 gene, which impairs inflammatory responses, is associated with reduced vascular inflammation (assessed by C-reactive protein [CRP]) and a decreased risk for CAD and diabetes.

Comparison of differing C-reactive protein assay methods and their impact on cardiovascular risk assessment.

A medium-sensitivity assay for C-reactive protein (CRP) was compared with a high-sensitivity, enhanced immunoturbidimetric assay in 803 angiographically studied patients. Different absolute CRP values were found by the assays, but there was a high correlation by quartile rank and similar predictive values for death and myocardial infarction. This suggests that the conclusions of previous studies performed using the medium-sensitivity assay are still valid but that cross-study comparisons should use percentile rank.