Arun Raghav Mahankali Sridhar

The Impact of Atrial Fibrillation and Its Treatment on Dementia

Atrial fibrillation (AF) is a very common tachyarrhythmia and is becoming increasingly prevalent, while dementia is a neurological condition manifested as loss of memory and cognitive ability. Both these conditions share several common risk factors. It is becoming increasingly evident that AF increases the risk of dementia. There are several pathophysiological mechanisms by which AF can cause dementia. AF increases the stroke risk and strokes are strongly associated with dementia. Besides stroke, altered cerebral blood flow in AF and cerebral microbleeds from anticoagulation may enhance the risk of dementia. Maintaining sinus rhythm may therefore decrease this risk. Catheter ablation is emerging as an effective alternative to maintain patients in sinus rhythm. This procedure has also shown promise in decreasing the risk of all types of dementia. Besides maintaining sinus rhythm and oral anticoagulation, aggressive risk factor modification may reduce the likelihood or delay the onset of dementia.

Neuronal control of experimental colitis occurs via sympathetic intestinal innervation

Vagus nerve stimulation is currently clinically evaluated as a treatment for inflammatory bowel disease. However, the mechanism by which this therapeutic intervention can have an immune‐regulatory effect in colitis remains unclear. We determined the effect of intestine‐specific vagotomy or intestine‐specific sympathectomy of the superior mesenteric nerve (SMN) on dextran sodium sulfate (DSS)‐induced colitis in mice. Furthermore, we tested the efficacy of therapeutic SMN stimulation to treat DSS‐induced colitis in rats.

Left atrial thrombus formation after successful left atrial appendage ligation: case series from a nationwide survey.

Percutaneous left atrial appendage (LAA) exclusion can be performed using endocardial occlusion devices or an endoepicardially placed suture delivery device (1-3). Thrombus formation on endocardial occlusion devices (Watchman, Boston Scientific, Marlborough, Massachusetts; or Amplatzer Cardiac Plug [ACP], St. Jude Medical, St. Paul, Minnesota) (1,2) has been attributed to platelet aggregation in the setting of a foreign body in the left atrium (LA). With the percutaneous endoepicardial ligation technique (Lariat, SentreHEART, Redwood City, California), there is no foreign body left behind, and the risk of thrombus formation should be insignificant. This study describes the clinical course of LA thrombi after the Lariat procedure in 19 patients. We conducted a nationwide survey of physicians performing procedures with the Lariat device in the United States to identify patients who developed LA thrombus after the procedure. Our study cohort comprised patients found to have LA thrombus post-procedure. Post-procedure surveillance imaging was not uniform across centers. Most patients underwent transesophageal echocardiogram (TEE)/computed tomography at 1 to 3 months post-procedure. Anticoagulation/antiplatelet therapy was initiated immediately after detection of LA thrombus. We collected demographic, clinical, and pre-procedural imaging characteristics of patients. Procedural variables and clinical course of patients after thrombus detection were recorded. Statistical analyses were performed using SPSS version 19.0 for Windows (SPSS, Inc., Chicago, Illinois). A total of 47 operators participated in the survey. Routine post-procedure imaging was performed by 44 (93.6%) operators. Three (6.4%) operators performed imaging only if clinically indicated. Routine post-procedure follow-up imaging was performed at 1 to 3 months and 3 to 6 months by 80% and 40% of the operators, respectively. Of the 964 patients who underwent the procedure, 19 (2%) had an LA thrombus. Table 1 lists some patient characteristics and includes follow-up data of the 19 patients. TABLE 1 Patient Characteristics and Follow-Up (n = 19) LA thrombus was detected within 90 days in 15 (79%) patients. TEEs performed in the first 6 months were negative for thrombi in 2 patients with clots discovered >200 days after the procedure. Eighteen patients received oral anticoagulants after detection of LA thrombus, whereas 1 patient received antiplatelet therapy. Thrombus remained unchanged at 90 days in the latter patient, requiring a switch to rivaroxaban. Serial TEEs were performed until thrombus resolution. Oral anticoagulation was discontinued in 16 patients after clot resolution, whereas 3 patients with unresolved thrombi remained on anticoagulation (30, 58, and 80 days, respectively). None of the patients had clinical evidence of stroke or peripheral embolism during follow-up. Our study highlights that the risk of LA thrombus formation with the device is low (2%). Most (79%) cases were detected within the first 90 days. Prompt initiation of anticoagulation can lead to thrombus resolution. This is the first investigation to describe the clinical course of LA thrombus post-procedure in a large cohort of patients receiving the Lariat device. In a clinical study involving 89 patients, no case of LA thrombus was detected on the 30-day post-procedure TEE. However, 1 patient had an LA thrombus away from the site of occlusion at 1-year follow-up (3). Our study is consistent in that, although uncommon, an LA thrombus can develop after the procedure. The pathophysiology of LA thrombus formation after the Lariat procedure remains unclear. Focal endocardial damage and inflammation around the LAA orifice secondary to tissue compression from the Lariat suture, causing edema and ischemic necrosis around the ligation site, can increase the propensity for LA thrombus formation. In our study, 17 of 19 (89%) patients developed a thrombus at the ligation site. Currently, there are no clear guidelines on LA thrombus surveillance after LAA ligation. We strongly support a follow-up TEE 30 to 90 days post-procedure. Given that the risk of thrombus formation is greatest during the first 3 months post-procedure, it may be appropriate for patients to receive antiplatelet or anticoagulant therapy during this period. The risk of LA thrombus in the absence of anticoagulation use post-procedure is low and is more frequently seen during the first 3 months after LAA ligation. Periodic imaging studies are essential for early detection of an LA thrombus. With prompt initiation of anticoagulation and close supervision, an LA thrombus can be managed safely.

Impact of gender on outcomes after atrial fibrillation ablation

a Metrohealth Medical Center, Case Western Reserve University, Cleveland, OH, United States b Division of Cardiovascular Diseases, Cardiovascular Research Institute, Mid-America Cardiology, University of Kansas Hospital & Medical Center, Kansas City, KS, United States c Division of Cardiovascular Medicine, State University of New York Downstate Medical Center, NY, United States d Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, NY, United States e Texas Cardiac Arrhythmia Institute, Austin, TX, United States f Department of Biomedical Engineering, University of Texas, Austin, TX, United States g Cardiovascular Division, Hospital of the University of Pennsylvania, Philadelphia, PA, United States

Cardiac Resynchronization Therapy US Trends and Disparities in Utilization and Outcomes

Background—The use of cardiac resynchronization therapy (CRT) has increased significantly since its initial approval in 2001 for use in patients with advanced heart failure. However, trends in utilization of CRT have not been systematically characterized. Methods and Results—We used the Nationwide Inpatient Sample database to identify all patients with CRT implantation during 2002 to 2010. The overall trends in CRT device implantation, patient characteristics, and outcomes were examined in detail and compared among demographic subgroups. During 2002 to 2010, a total of 374 202 CRT procedures were recorded. Significant and persistent gender and racial disparities favoring men (71.4%) and white (79.6%), respectively, were noted in all years. The highest number of CRT devices were implanted in the 65- to 84-year age group (64.6%), with significant increase in number of CRT implants in older patients ≥85 years over the years (P=0.02). The CRT-associated in-hospital mortality improved from 1.08% in 2003 to 0.70% in 2010 (P=0.03). The correlates of higher mortality included males (0.93% versus 0.71% in females; P=0.04) and older age (age ≥85 years had 1.5% mortality versus 0.8% for age <85 year; P<0.001). The mean hospital length of stay for CRT decreased, while mean CRT-associated hospital charges increased progressively over the years. Factors associated with higher charges were gender (males>females), older age, and greater comorbidities. Conclusions—CRT implantation is a relatively safe procedure that has become safer in higher risk patients. However, significant disparities in CRT utilization exist in certain demographic subgroups, and these disparities have persisted across the years.

Impact of haematoma after pacemaker and CRT device implantation on hospitalization costs, length of stay, and mortality: a population-based study

AIMS Pocket haematoma is a common complication following pacemaker implantation. Impact of this complication on post-procedural outcomes has previously not been systematically studied. We sought to identify the incidence of pocket haematoma after a de novo pacemaker and cardiac resynchronization therapy (CRT) device implantation and evaluate its impact on the hospital outcomes using a large all-payer national inpatient database. METHODS AND RESULTS Data from Nationwide Inpatient Sample 2010 was queried to identify all primary implantations of single chamber, dual chamber pacemakers, and biventricular devices during the year 2010 using the appropriate ICD-9 codes. Patients who experienced a procedure-related haematoma during the hospital stay were identified. Of a total of 78,751 primary pacemaker implantations in the year 2010, 1677 (2.1%) of the implantations were complicated by a pocket haematoma. Higher age groups, more complex pacemaker types (BiV > dual chamber > single chamber), and comorbidities such as congestive heart failure and coagulopathy were associated with an increased risk of pocket haematoma formation post-pacemaker implantation. Patients who developed a pocket haematoma had a longer length of stay (8.7 vs. 4.8 days, P < 0.001), higher hospitalization costs (

LEFT ATRIAL APPENDAGE LIGATION AND ABLATION FOR PERSISTENT ATRIAL FIBRILLATION (LAALA-AF REGISTRY)

48,815 vs.

HYPONATREMIA AND HEMODYNAMIC CHANGES FOLLOWING PERCUTANEOUS LEFT ATRIAL APPENDAGE LIGATION WITH THE LARIAT DEVICE

34,324, P < 0.001) and higher in-hospital mortality (2.0 vs. 0.7%, P < 0.001) compared with patients who did not develop a haematoma. CONCLUSIONS Haematoma is a relatively common complication associated with pacemaker implantation; however, it adversely impacts in-hospital outcomes.

VERNAKALANT FOR RAPID CARDIOVERSION OF RECENT ONSET ATRIAL FIBRILLATION: A META-ANALYSIS

Left atrial appendage (LAA) isolation is known to be an important adjunctive therapy to improve outcomes of pulmonary vein isolation in patients with persistent AF. Percutaneous endo-epicardial LAA closure system (LARIAT) can result in both mechanical and electrical exclusion of the LAA and may

PERI-PROCEDURAL USE OF NOVEL ANTICOAGULATION AGENTS DURING CARDIAC DEVICE IMPLANTATION

introduction: The left atrial appendage (LAA) is a major source of ANP (atrial natriuretic peptide). ANP secretion post-MAZE has been shown to be reduced, resulting in volume overload and hyponatremia. However, the physiologic effects of LAA ligation have not been previously studied. We intended to study the changes in electrolytes and blood pressure (BP) following percutaneous LAA ligation using the LARIAT device.