Vincent See

Percutaneous patent foramen ovale and atrial septal defect closure in adults: Results and device comparison in 100 consecutive implants at a single center

Closure of interatrial septal defects with percutaneous devices is increasingly common. However, the indications for closure and techniques for device implantation are diverse. We reviewed our first 100 consecutive implants to assess and compare the indications, results, complications, and evolution of techniques for percutaneous patent foramen ovale (PFO) and atrial septal defect (ASD) closure. The mean age of patients was 52 years and 70% were female. Paradoxical embolism was the predominant indication (94%) for PFO closure and significant left‐to‐right shunt was the most frequent indication (89%) for ASD closure. Implantation success was 94% with major complications in 3 patients (2.8%). Transesophageal echocardiography was utilized in the initial 27 procedures and then replaced by intracardiac echocardiography in subsequent ones, with an associated reduction in procedure and physician time. During 6 months of follow‐up, 3 patients were readmitted for atrial arrhythmias (2 patients) and an MRI‐negative neurologic event (1 patient). Echocardiography at 6 months in 83% of the PFO patients revealed moderate and severe positive contrast studies for right‐to‐left shunting in one third of patients, with differences between devices and insertion techniques. This single‐center experience with percutaneous device closure of PFO and ASD in adults demonstrates excellent results with few complications. Catheter Cardiovasc Interv 2005;64:197–203.

Effect of Atorvastatin on Postcardiac Transplant Increase in Low-Density Lipoprotein Cholesterol Reduces Development of Intimal Hyperplasia and Progression of Endothelial Dysfunction

Following cardiac transplantation, accelerated coronary disease limits long-term survival. Because statins may reduce the progression of the disease in part by their anti-inflammatory effects, this study was designed to assess if atorvastatin prevented neointimal hyperplasia and endothelial dysfunction independently of baseline cholesterol levels. Patients were randomized to usual therapy (n = 13) or to 10 to 20 mg of atorvastatin (n = 12). Control subjects received niacin when their low-density lipoprotein (LDL) cholesterol levels were >130 mg/dl (n = 4). Neointimal hyperplasia by intracoronary ultrasonography, endothelial dependent vascular reactivity, and coronary flow reserve were measured at baseline and 1 year. Control group total cholesterol (203 +/- 11 to 200 +/- 13 mg/dl) and LDL (116 +/- 10 to 119 +/- 11 mg/dl) remained stable, whereas there was a nonsignificant reduction at 12 months in the atorvastatin group (total cholesterol 216 +/- 28 to 178 +/- 21 mg/dl; LDL 126 +/- 17 to 100 +/- 18 mg/dl). At 2 to 3 months there was a significant increase in total cholesterol and LDL cholesterol that was reduced with atorvastatin. At 1 year, patients taking atorvastatin showed a decrease in new or progressing lesions (2.5 +/- 1.7 vs 4.2 +/- 1.8 lesions/patient, p = 0.02), progression of maximal intimal thickness (0.12 +/- 0.07 vs 0.52 +/- 0.17 mm, p = 0.04), and percent area stenosis (5.9 +/- 2.2% vs 19.0 +/- 5.5%, p = 0.04). Atorvastatin ameliorated progressive endothelial dysfunction, whereas coronary flow reserve was unchanged in both groups. Atorvastatin administered to patients with normal or mild hypercholesterolemia in the initial year after transplant reduced the initial increase in LDL cholesterol, and, by doing so, prevented the development and progression of coronary artery lesions and endothelial dysfunction with only mild long-term decreases in cholesterol levels.

Three-dimensional 123I-meta-iodobenzylguanidine cardiac innervation maps to assess substrate and successful ablation sites for ventricular tachycardia: feasibility study for a novel paradigm of innervation imaging.

Background—Innervation is a critical component of arrhythmogenesis and may present an important trigger/substrate modifier not used in current ventricular tachycardia (VT) ablation strategies. Methods and Results—Fifteen patients referred for ischemic VT ablation underwent preprocedural cardiac 123I- meta-iodobenzylguanidine (123I-mIBG) imaging, which was used to create 3-dimensional (3D) innervation models and registered to high-density voltage maps. 3D 123I-mIBG innervation maps demonstrated areas of complete denervation and 123I-mIBG transition zone in all patients, which corresponded to 0% to 31% and 32% to 52% uptake. 123I-mIBG denervated areas were ≈2.5-fold larger than bipolar voltage–defined scar (median, 24.6% [Q1–Q3, 18.3%–34.4%] versus 10.6% [Q1–Q3, 3.9%–16.4%]; P<0.001) and included the inferior wall in all patients, with no difference in the transition/border zone (11.4% [Q1–Q3, 9.5%–13.2%] versus 16.6% [Q1–Q3, 12.0%–18.8%]; P=0.07). Bipolar/unipolar voltages varied widely within areas of denervation (0.8 mV [Q1–Q3, 0.3–1.7 mV] and 4.0 mV [Q1–Q3, 2.9–5.6 mV]) and 123I-mIBG transition zones (0.8 mV [Q1–Q3, 0.4–1.8 mV] and 4.6 mV [Q1–Q3, 3.2–6.3 mV]). Bipolar voltages in denervated areas and 123I-mIBG transition zones were <0.5 mV, 0.5 to 1.5 mV, and >1.5 mV in 35%, 36%, and 29%, as well as 35%, 35%, and 30%, respectively (P>0.05). Successful ablation sites were within bipolar voltage–defined scar (7%), border zone (57%), and areas of normal voltage (36%), but all ablation sites were abnormally innervated (denervation/123I-mIBG transition zone in 50% each). Conclusions—123I-mIBG innervation defects are larger than bipolar voltage–defined scar and cannot be detected with standard voltage criteria. Thirty-six percent of successful VT ablation sites demonstrated normal voltages (>1.5 mV), but all ablation sites were within the areas of abnormal innervation. 123I-mIBG innervation maps may provide critical information about triggers/substrate modifiers and could improve understanding of VT substrate and facilitate VT ablation. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique Identifier: NCT01250912.

Inflammation and sudden cardiac death in a community-based population of older adults: The Cardiovascular Health Study

BACKGROUND Inflammation is linked to adverse cardiovascular events, but its association with sudden cardiac death (SCD) has been controversial. Older subjects, who are at particular risk for SCD, were underrepresented in previous studies addressing this issue. OBJECTIVE The purpose of this study was to study the association between inflammation and SCD in a community-based population of older adults. METHODS In the Cardiovascular Health Study, 5806 and 5382 participants had measurements of C-reactive protein (CRP) and interleukin-6 (IL6), respectively, and were followed for up to 17 years. SCD risk as a function of baseline IL-6 and CRP was assessed in the overall population and in a group of participants without known prevalent cardiac disease. RESULTS In univariate analyses, both IL-6 (hazard ratio [HR] 1.79 for 1+ log IL-6, 95% confidence interval [CI] 1.50-2.13; 5th vs 1st quintile HR 3.36, 95% CI 2.24-5.05) and CRP (HR 1.31 for 1+ log CRP, 95% CI 1.18-1.45; 5th vs 1st quintile HR 2.00, 95% CI 1.40-2.87) were associated with SCD risk. In covariate-adjusted analyses, accounting for baseline risk factors, incident myocardial infarction, and heart failure, the association with SCD risk persisted for IL-6 (HR 1.26 for 1+ log IL-6, 95% CI 1.02-1.56; 5th vs 1st quintile HR 1.63, 95% CI 1.03-2.56) but was significantly attenuated for CRP (HR 1.13 for 1+ log CRP, 95% CI 1.00-1.28; 5th vs 1st quintile HR 1.34, 95% CI 0.88-2.05). Similar findings were observed in participants without prevalent cardiac disease. CONCLUSION Greater burden of inflammation, assessed by IL-6 levels, is associated with SCD risk beyond traditional risk factors, incident myocardial infarction, and heart failure.

Impact of ICD Artifact Burden on Late Gadolinium Enhancement Cardiac MR Imaging in Patients Undergoing Ventricular Tachycardia Ablation

Cardiac magnetic resonance imaging (CMRI) is the gold standard for myocardial scar evaluation. Although ideal for substrate assessment in ventricular tachycardia (VT), most patients have an implantable cardioverter‐defibrillator (ICD) at presentation for ablation. This study evaluates the ICD artifact burden during standard late gadolinium enhancement CMRI (LGE‐CMRI) evaluation of myocardial scar in VT patients with ICDs.

Relative contributions of intimal hyperplasia and vascular remodeling in early cardiac transplant-mediated coronary artery disease.

The relative contribution of intimal hyperplasia and vascular remodeling in early transplant coronary artery disease (TxCAD) is unknown. This study was designed to determine the contributions of vascular remodeling and intimal hyperplasia in the initial year after transplantation by intravascular ultrasound (IVUS). Twenty-five patients underwent baseline (<6 weeks after transplant) and 1-year angiography and IVUS to evaluate total vessel, luminal, and intimal + medial areas in >or=3 segments of the coronary artery. Nine patients had donor atherosclerotic disease on baseline study (23% of segments), and at 1-year, 21 patients (84%) had intimal hyperplasia (70% of segments). Fourteen patients had positive remodeling in all arterial segments, whereas the remaining 11 had positive and negative remodeling in the same vessel. Mean plaque area and total vessel area increased significantly (p = 0.0001) in proximal, mid, and distal segments, whereas total vessel area was most pronounced in distal segments. Luminal area did not change over time. Of the 87 segments evaluated, 68 (78%) had an increase in total vessel area, 57 (66%) had intimal growth, and 54 (62%) had an increase in luminal area. Although changes in total vessel and luminal area were closely correlated, a decrease in luminal area was associated with positive and negative remodeling. In conclusion, luminal area is generally maintained during the initial transplant year despite significant intimal hyperplasia due to positive remodeling. Reduction in the luminal area results from either inadequate positive remodeling or negative remodeling without intimal growth and often occurs in the same artery.

Global and Regional Myocardial Innervation Before and After Ablation of Drug-Refractory Ventricular Tachycardia Assessed with 123I-MIBG

Cardiac innervation is a critical component of ventricular arrhythmogenesis that can be noninvasively assessed with 123I-MIBG. However, the effect of ventricular tachycardia (VT) ablation on global and regional left ventricular sympathetic innervation and clinical outcomes has not been previously assessed. Methods: In this prospective, single-center feasibility study, 13 patients with cardiomyopathy (n = 9 ischemic, n = 4 nonischemic) who were scheduled to undergo ablation of drug-refractory VT underwent 15-min and 4-h 123I-MIBG scans before and 6 mo after the ablation procedure. Planar and arrhythmia-specific 757-segment analysis of short-axis SPECT images was performed in all datasets. Results: Global innervation assessed with heart-to-mediastinal ratio and washout rates was preserved in all patients at baseline (1.8 [continuous variables are expressed as median and quartile: Q1–Q3, 1.7–2.4] and 54% [Q1–Q3, 47%–67%]) and did not change significantly at the 6-mo follow-up (1.9 [Q1–Q3, 1.6–2.2], P = 0.9; and 56% [Q1–Q3, 41%–62%], P = 0.6). However, segmental analysis demonstrated that ischemic patients had larger areas of abnormal innervation at baseline (52.1% vs. 19.6%, P = 0.011) and at the 6-mo follow-up (56.7% vs. 27.5%, P = 0.011) than the nonischemic patients. Innervation defects affected 40% of the inferior segments in all ischemic cardiomyopathy patients, whereas they affected only 10% of inferior segments in 75% of nonischemic patients. When segmental data were further analyzed in denervated (DZ), transition (TZ), and normal (NZ) zones, there were changes in these designated innervation categories from baseline to the 6-mo follow-up for ischemic (19% DZ, 59% TZ, 22% NZ) and nonischemic (6% DZ, 45% TZ, 15% NZ) patients. In ischemic patients, relative changes were significantly greater in the TZ segments than in the DZ, which demonstrated the second highest proportional changes (P = 0.028). Receiver operating characteristic curves defined best cutoffs of DZ, TZ, and NZ as less than 30.5%, 30.6%–47.1%, and more than 47.1%, respectively. Conclusion: Patients with ischemic cardiomyopathy have larger areas of abnormal innervation than those with nonischemic cardiomyopathy. Although VT ablation did not change global innervation, a novel arrhythmia-specific segmental analysis demonstrated significant dynamic changes in innervation categories and allowed quantitative definitions of DZ, TZ, and NZ. These findings provide novel insights into the mechanics of sympathetic innervation in patients undergoing VT ablation and may have diagnostic and therapeutic implications.

Safety of computed tomography in patients with cardiac rhythm management devices: Assessment of the U.S. food and drug administration advisory in clinical practice

OBJECTIVES To assess the safety of computed tomography (CT) imaging in patients with cardiac rhythm management (CRM) devices, which was subject to an advisory from the U.S. Food and Drug Administration (FDA) in 2008. BACKGROUND The FDA warned about potential interference of CT imaging with CRM devices and made recommendations for clinical practice despite only limited evidence. METHODS All 516 CT scans that involved direct radiation exposure of CRM devices (332 defibrillators, 184 pacemakers) at 2 large-volume centers between July 2000 and May 2010 were included. The primary outcome was a composite endpoint of death, bradycardia or tachycardia requiring termination of the scan or an immediate intervention, unplanned hospital admission, reprogramming of the device, inappropriate defibrillator shocks, or device replacement/revision thought to be due to CT imaging. Significant changes in device parameters were sought as a secondary outcome (control group 4:1 ratio). RESULTS The main finding was that none of the CTs were associated with the primary outcome. With serial device interrogations, there were no differences in changes in battery voltage or lead parameters between devices exposed to radiation and their controls. Potentially significant changes in device parameters were observed in a small group of devices (both the CT group and control group), but no definitive link to CT was confirmed, and there were no associated clinical consequences. CONCLUSIONS The findings suggest that the presence of CRM devices should not delay or result in cancellation of clinically indicated CT imaging procedures, and provide evidence that would be helpful when the FDA advisory is re-evaluated.

Acute Management of Atrial Fibrillation : From Emergency Department to Cardiac Care Unit

Atrial fibrillation (AF) is the most common tachyarrhythmia encountered in clinical practice. One-third of hospitalizations in the United States are attributed to AF, with increasing rates in the past decade. Significant morbidity and mortality, including ∼15% to 20% of all ischemic strokes, result from AF. AF is associated with many causes and comorbidities. Hallmarks of acute AF management are accurate diagnosis, clinical stabilization, symptom relief through rate or rhythm control, thromboembolic stroke risk modification, and treatment of underlying causes. Meticulous and individualized acute evaluation based on these goals facilitates successful transition to long-term collaborative optimization of outcomes.

Validation of a novel CARTOSEG™ segmentation module software for contrast-enhanced computed tomography-guided radiofrequency ablation in patients with atrial fibrillation: IMANLI et al.

Visualization of left atrial (LA) anatomy using image integration modules has been associated with decreased radiation exposure and improved procedural outcome when used for guidance of pulmonary vein isolation (PVI) in atrial fibrillation (AF) ablation. We evaluated the CARTOSEG™ CT Segmentation Module (Biosense Webster, Inc.) that offers a new CT‐specific semiautomatic reconstruction of the atrial endocardium.