Comparison of peri-procedural anticoagulation with rivaroxaban and apixaban during radiofrequency ablation of atrial fibrillation.

INTRODUCTION: Prospective studies on rivaroxaban and apixaban have shown the safety and efficacy of direct anticoagulation agents (DOAC)s used peri-procedurally during radiofrequency ablation (RFA) of atrial fibrillation (AF). Studies comparing the two agents have not been performed. METHODS: Consecutive patients from a prospective registry who underwent RFA of AF between April 2012 and March 2015 and were on apixaban or rivaroxaban were studied. Clinical variables and outcomes were noted. RESULTS: There were a total of 358 patients (n = 56 on apixaban and n = 302 on rivaroxaban). There were no differences in baseline characteristics between both groups. The last dose of rivaroxaban was administered the night before the procedure in 96% of patients. In patients on apixaban, 48% of patients whose procedure was in the afternoon took the medication on the morning of the procedure. TIA/CVA occurred in 2 patients (0.6%) in rivaroxaban group with none in apixaban group (p = 0.4). There was no difference in the rate of pericardial effusion between apixaban and rivaroxaban groups [1.7% vs 0.6% (p = 0.4)]. Five percent of patients in both groups had groin complications (p = 0.9). In apixaban group, all groin complications were small hematomas except one patient who had a pseudoaneurysm (1.6%). One pseudo-aneurysm, 1 fistula and 3 large hematomas were noted in patients on rivaroxaban (1.7%) with the rest being small hematomas. DOACs were restarted post procedure typically 4 h post hemostasis. CONCLUSIONS: Peri-procedural uninterrupted use of apixaban and rivaroxaban during AF RFA is safe and there are no major differences between both groups.

Safety and efficacy of leadless pacemaker for cardioinhibitory vasovagal syncope.

BACKGROUND: Single-chamber leadless pacemakers (LPs) have been shown to be an effective alternative to conventional transvenous pacemakers (CTPs), but their benefit in the context of cardioinhibitory vasovagal syncope (CI-VVS) is unknown. OBJECTIVE: The purpose of this study was to evaluate the safety and efficacy of LP compared with dual-chamber CTP for CI-VVS. METHODS: We conducted a multicenter, retrospective study comparing patients who received LP or dual-chamber CTP for drug-refractory CI-VVS. CI-VVS was diagnosed clinically and supported by cardiac monitoring and head-up tilt table testing. The primary efficacy endpoint was freedom from syncope during follow-up. Secondary endpoints included device efficacy and safety estimated by device-related major and minor adverse events (AEs). RESULTS: Seventy-two patients (24 LP, 48 CTP; age 32 ± 5.5 years; 90% female; syncope frequency 7.6 ± 3.4 per year) were included. At 1 year, 91% of patients (22/24) in the LP group and 94% of patients (43/48) in the CTP group met the primary efficacy endpoint (P = .7). Device efficacy endpoint was met in 92% of the LP group and 98% of the CTP group (P = .2). Early major AEs occurred in 2 of 24 in the LP group and 3 of 48 in the CTP group (P = .4). Late major AEs occurred in 0 of 24 in the LP group and 2 of 48 in the CTP group (P = 1). CONCLUSION: In patients with CI-VVS, single-chamber LP demonstrated equivalent efficacy in reducing syncopal events compared to dual-chamber CTP, with a similar safety profile.

Peri-procedural use of direct anticoagulation agents during cardiac device implantation: vitamin K antagonists vs direct oral anticoagulants.

BACKGROUND: Warfarin is deemed safe compared to bridging with heparin in the peri-procedure setting while implanting cardiac devices. The timing of discontinuation and re-initiation of direct anticoagulant agents (DOACs) such as dabigatran, apixaban, and rivaroxaban in the peri-procedural setting in comparison to warfarin is not well studied. OBJECTIVE: We wanted to compare three DOAC agents with warfarin during cardiac device implantation. METHODS: Consecutive patients on treatment with dabigatran, rivaroxaban, or apixaban (group A) undergoing a cardiac device generator change, upgrade, or new implantation procedure were compared to those on warfarin (group B). Incidence of hematoma, infection, effusion, stroke, and other complications were noted at 1 day, 1 week, and 3 months. RESULTS: A total of 311 patients in group A underwent the above procedures with 73 patients on dabigatran, 153 on rivaroxaban, and 85 on apixaban. There were 467 patients on warfarin in group B. Mean age of the total population was 68 ± 12 years with 67% males and > 80% Caucasians. The last dose of the DOAC was the night prior to the procedure and resumed the night of the procedure (single dose interruption for apixaban and dabigatran and no un-interruption for rivaroxaban). There was no difference noted in the incidence of minor or major hematoma (9% vs 8.5%, p = 0.7). No stroke occurred in either group. CONCLUSION: Use of DOAC agents with transient interruption of one dose is as safe as warfarin in the peri-procedural setting during implantation of cardiac devices.

Myocarditis Causing Premature Ventricular Contractions: Insights From the MAVERIC Registry.

BACKGROUND: Premature ventricular contractions are a common clinical presentation that drives further diagnostic workup. We hypothesize the presence of underlying inflammation is often unrecognized in these patients with a potential for continued disease progression if not diagnosed and treated early in the disease course. METHODS: This is a single-center, prospective study including 107 patients with frequent symptomatic premature ventricular contractions (>5000/24 h) and no known ischemic heart disease. Patients underwent a combination of laboratory testing, 18F-fluorodeoxyglucose positron emission tomography scan, cardiac magnetic resonance imaging, and biopsy. Patients were diagnosed with myocarditis based on a multidisciplinary approach and treated with immunosuppressive therapy. RESULTS: The mean age of the cohort was 57±15 years, 41% were males, and left ventricular ejection fraction was 47±11.8%. Positive positron emission tomography scan was seen in 51% (55/107), of which 51% (28/55) had preserved left ventricle function. Based on clinical profile, 18F-fluorodeoxyglucose-positron emission tomography imaging, cardiac magnetic resonance, and histological data 58% patients (32/55) received immunosuppressive therapy alone and 25.4% (14/55) received immunosuppressive therapy and catheter ablation. Optimal response was seen in 67% (31/46) over a mean follow-up of 6±3 months. In patients with left ventricle systolic dysfunction, 37% (10/27) showed an improvement in mean left ventricular ejection fraction of 13±6%. CONCLUSIONS: Approximately 51% of patients presenting with frequent premature ventricular contractions have underlying myocardial inflammation in this cohort. 18F-fluorodeoxyglucose-positron emission tomography scan can be a useful modality for early diagnosis and treatment with immunosuppressive therapy in selected patients can improve clinical outcomes.

Assessment of DNA Damage After Ionizing Radiation Exposure in Patients Undergoing Cardiac Resynchronization Therapy Device Implantation or Atrial Fibrillation Ablation (The RADAR Study).

BACKGROUND: There is limited data regarding effect of prolonged radiation exposure during electrophysiological (EP) procedures on direct DNA damage. Comet test has shown to assess DNA damage following radiation exposure. METHODS: We performed a single-center prospective observational study assessing direct DNA damage using the quantitative comet assay in patients undergoing cardiac resynchronization (CRT) and atrial fibrillation (AF) catheter ablation procedures. Venous comet assay was performed pre, immediately post procedure and at 3-month duration in twenty-two (N=22) patients who underwent catheter ablation for symptomatic AF and fourteen (N=14) patients who underwent CRT implantation. RESULTS: The median [interquartile range (IQR)] fluoroscopy time, radiation dose and dose area product (DAP) were 34.3 (27.97 - 45.48) minutes, 853.07 (611.36 - 1334.76) mGy and 16,994.10 (9,023.65 - 58,845.00) UGym2 in the ablation group and 30.05 (18.75 - 37.33) minutes, 345.00 (165.09 - 924.79) mGy and 11,837.20 [7182.67 - 35567.75] UGym2 in the CRT group. When compared with pre-procedure, there was a statistically significant increase in median (IQR) DNA migration on comet assay in the ablation group immediately post procedure [+6.55 µm (0.78, 10.25, p=0.02)] that subsequently decreased at 3 months [-1.00 µm (-2.20, 0.78), p=0.03] but not in the CRT group. CONCLUSION: There was a significant increase in DNA damage as detected by comet assay immediately post procedure that normalized at 3 months in patients undergoing AF ablation. Further large prospective studies are warranted to evaluate the impact of this prolonged radiation exposure and DNA damage on long-term follow up.

Epicardial Left Atrial Appendage Exclusion Reduces Blood Pressure in Patients With Atrial Fibrillation and Hypertension.

BACKGROUND: Percutaneous left atrial appendage exclusion (LAAE) has evolved as an alternative strategy for stroke prevention in atrial fibrillation (AF). Recent observational data have suggested that epicardial LAAE can have substantial impact on arrhythmia burden and hemodynamic profile. OBJECTIVES: The authors aimed to study the impact of epicardial versus endocardial LAAE on systemic blood pressure in hypertensive AF patients. METHODS: This was a prospective, nonrandomized study comparing 247 patients who underwent epicardial LAAE with 124 patients with endocardial exclusion. Clinical outcomes were measured at 3 months and 1 year. Primary outcome was improvement in systolic blood pressure (SBP) between both groups compared with baseline. Secondary outcome included changes in diastolic pressures (DBP), serum electrolytes, and creatinine. RESULTS: There was no significant difference in baseline SBP between epicardial and endocardial groups. SBP was significantly lower in the epicardial group both at 3 months (122 ± 11.8 mm Hg vs. 129.7 ± 8.2 mm Hg; p < 0.001) and 1 year (123 ± 11.6 mm Hg vs. 132.2 ± 8.8 mm Hg; p < 0.001) compared with the endocardial group. An adjusted multivariate linear mixed effects model demonstrated that epicardial LAAE significantly decreased SBP by 7.4 mm Hg at 3 months and by 8.9 mm Hg at 1 year (p < 0.0001). There was a trend toward lower DBP with epicardial LAAE at 3 months by 1.3 mm Hg (p = 0.2) and at 1 year by 1.8 mm Hg (p = 0.09). There was no significant difference in serum electrolytes and creatinine between both groups. CONCLUSIONS: In hypertensive AF patients, epicardial LAAE significantly decreases SBP both at 3 and 12 months compared with endocardial exclusion.

Safety and feasibility of leadless pacemaker in patients undergoing atrioventricular node ablation for atrial fibrillation.

BACKGROUND: Atrioventricular node (AVN) ablation and permanent pacing is an established strategy for rate control in the management of symptomatic atrial fibrillation (AF). Leadless pacemakers (LPs) can overcome some of the short-term and long-term limitations of conventional transvenous pacemakers (CTPs). OBJECTIVES: The purpose of this study was to compare the feasibility and safety of LP with those of single-chamber CTP in patients with AF undergoing AVN ablation. METHODS: We conducted a multicenter observational study of patients undergoing AVN ablation and pacemaker implantation (LP vs single-chamber CTP) between February 1, 2014 and November 15, 2016. The primary efficacy end points were acceptable sensing (R wave amplitude ≥5.0 mV) and pacing thresholds (≤2.0 V at 0.4 ms) at follow-up. Safety end points included device-related major and minor (early <1 month, late >1 month) adverse events. RESULTS: A total of 127 patients with LP (n = 60) and CTP (n = 67) were studied. The median follow-up was 12 months (interquartile range 12-18 months). Ninety-five percent of the LP group and 97% of the CTP group met the primary efficacy end point at follow-up (57 of 60 vs 65 of 67; P = .66). There was 1 major adverse event (loss of pacing and sensing) in the LP group and 2 (lead dislodgement) in the CTP group (1 of 60 vs 2 of 67; P = 1.00). There were 6 minor adverse events (5 early and 1 late) in the LP group and 3 (early) in the CTP group (6 of 60 vs 3 of 67; P = .30). CONCLUSION: Our results demonstrate the feasibility and safety of LP compared with CTP in patients undergoing AVN ablation for AF.

Mechanical function of the left atrium is improved with epicardial ligation of the left atrial appendage: Insights from the LAFIT-LARIAT Registry.

BACKGROUND: Left atrial (LA) strain (ε) and ε rate (SR) analysis by 2-dimensional speckle tracking echocardiography is a novel method for functional assessment of the LA. OBJECTIVE: The purpose of this study was to determine the impact of left atrial appendage (LAA) exclusion by Lariat epicardial ligation on mechanical function of the LA by performing ε and SR analysis before and after the procedure. METHODS: A total of 66 patients who underwent successful LAA exclusion were included in the study. Of these 66 patients, 32 had adequate paired data for ε and SR analysis. SR during ventricular systole (LA-SRs) represents LA reservoir function, and SR during early ventricular diastole (LA-SRe) represents LA conduit function. ε and SR were determined from apical 4- and 2-chamber views using the electrocardiographic QRS as a reference point. LA volume index as surrogate for LA remodeling was measured from apical views. RESULTS: Mean patient age was 70 ± 9.2 years. LAA ligation resulted in improved reservoir function (LA-SRs: pre 0.72, confidence interval [CI] 0.63-0.83 vs post 0.81, CI 0.73-0.98; P = .043) and conduit function (LA-SRe: pre 0.74, CI 0.67-0.99 vs post 0.89, CI 0.82-1.07; P = .025). LA volume index improved significantly with the Lariat (pre 35.4, CI 29.4-37.2 vs post 29.2, CI 28.2-35.9; P <.023). CONCLUSION: LAA exclusion seems to improve mechanical function of the LA and results in reverse LA remodeling.

Impact of Radiofrequency Ablation of Atrial Fibrillation on Pulmonary Vein Cross Sectional Area: Implications for the Diagnosis of Pulmonary Vein Stenosis.

INTRODUCTION: Restoration of normal sinus rhythm by radiofrequency ablation (RFA) in atrial fibrillation (AF) patients can result in a reduction of left atrial (LA) volume and pulmonary vein (PV) dimensions. It is not clear if this PV size reduction represents a secondary effect of overall LA volume reduction or true PV stenosis. We assessed the relationship between LA volume reduction and PV orifice area pre- and post-RFA. METHODS: A retrospective cohort study was conducted at a tertiary care academic hospital. Pre- and post-RFA cardiac computed tomography (CT) studies of 100 consecutive AF patients were reviewed. Studies identifying obvious segmental PV narrowing were excluded. Left atrial volumes and PV orifice cross-sectional areas (PVOCA) were measured using proprietary software from the CT scanner vendor (GE Healthcare, Waukesha, WI). RESULTS: The cohort had a mean age of 60 ± 8 years, 73% were male, and 90% were Caucasian. Non-paroxysmal AF was present in 76% of patients with a mean duration from diagnosis to RFA of 55 ± 54 months. Mean procedural time was 244 ± 70 min. AF recurred in 27% at 3 month follow-up. Pre-RFA LA volumes were 132 ± 60 ml and mean PVOCA was 2.89 ± 2.32 cm2. In patients with successful ablation, mean LA volume decreased by 10% and PVOCA decreased by 21%. PVOCA was significantly reduced in patients with successful RFA compared to those who had recurrence (2.18 ± 1.12 vs. 2.8 ± 1.9 cm2, p = 0.04) but reduction in LA volume between groups was not significant (118 ± 42 vs. 133 ± 54 ml, p=0.15). CONCLUSIONS: The study demonstrates that both PV orifice dimensions and LA volume are reduced after successful AF ablation. These data warrant a reassessment of criteria for diagnosing PV stenosis based on changes in PV caliber alone, ideally incorporating LA volume changes.

Replacing warfarin with a novel oral anticoagulant: Risk of recurrent bleeding and stroke in patients with warfarin ineligible or failure in patients with atrial fibrillation (The ROAR study).

BACKGROUND: A significant proportion of patients treated with warfarin for atrial fibrillation (AF) become warfarin ineligible (WI) due to major bleeding events (MBE) or systemic thromboembolism (STE). We report a large multicenter real-world experience of the use of direct oral antagonists (DOACs) in these WI patients. METHODS: We report the outcomes of 263 WI patients treated with DOACs. The primary objective was to evaluate clinical outcomes of STE and MBE with DOACs. Secondary objective was to assess clinical predictors of repeat MBE and STE on DOACs. RESULTS: Note that 63% (166 of 263) patients had a repeat MBE on DOACs. Repeat MBE was significantly higher in patients with prior gastrointestinal bleeding (74.5% vs. 30%, P < 0.0001). Five percent (12 of 263) developed repeat STE. Higher mean CHA2DS2VASC (6.5 ± 1.7 vs. 3.3 ± 1.6 = 0.001) score was associated with repeat STE. About 34% (57 of 166) of patients had an intervention to manage repeat MBE. LAAO devices were successfully used in 67% (12 of 18) high-risk patients who underwent major interventions to manage MBE. CONCLUSION: In WI patients rechallenged with DOACs, a significant proportion developed repeat MBE. LAAO devices seem reasonable in those patients who undergo major interventions to manage MBE with cautious and temporary continuation of DOAC.

Risk of ventricular tachyarrhythmias following improvement of left ventricular ejection fraction in patients with implantable cardiac defibrillators implanted for primary prevention of sudden cardiac death.

PURPOSE: In patients who undergo implantable cardiac defibrillator (ICD) implantation for primary prevention of sudden cardiac death (SCD), data is unclear whether their ICD generator needs to be replaced at end of life if their left ventricular ejection fraction (EF) improves. Despite improvement in EF, the underlying scar may represent a potential substrate for ventricular arrhythmias. METHODS: Data on 280 patients who underwent ICD implantation for primary prevention of SCD was obtained from two centers. Patients were followed for any improvement in EF to ≥35%. All arrhythmic events during follow-up, including appropriate and inappropriate shocks/ATP, were recorded. RESULTS: Thirty percent (n = 86/280) of patients improved their EF to >35% of which 41% (n = 37) underwent a generator change by the study ending period with the rest not yet at ERI. Mean baseline EF in patients with and without target EF improvement was 26 ± 7 and 23 ± 7% (p = 0.2). After excluding patients whose arrhythmic events data were unavailable, the final sample consisted of 62 patients in the EF improvement group and 156 patients in the group without EF improvement. In the group with EF improvement, appropriate events (shock + ATP) were noted in 19% of patients (n = 12/62) and inappropriate shocks and ATP in 6% of (n = 4/62) patients after their EF improved to >35%. Four patients received appropriate therapies when their EF was low prior to improvement. In contrast, in patients who had no improvement in EF, 27% (n = 43/156) received an appropriate therapy (p = 0.6) while 11% (n = 18/156) (p = 0.2) received inappropriate shocks and ATP. All-cause mortality was higher in patients without subsequent improvement in EF versus those with EF improvement (31 vs. 15% (p = .005). CONCLUSIONS: There was no significant difference in the number of appropriate therapies received by each group. Patients continue to be at high risk for sudden cardiac death despite improvement in EF.

Systemic Octreotide Therapy in Prevention of Gastrointestinal Bleeds Related to Arteriovenous Malformations and Obscure Etiology in Atrial Fibrillation.

OBJECTIVES: The present study describes the use of octreotide (OCT) in patients with atrial fibrillation (AF) receiving oral anticoagulation (OAC) who have gastrointestinal (GI) bleeding related to arteriovenous malformations (AVMs), as well as its effect on OAC tolerance and subsequent rebleeding. BACKGROUND: AVMs cause significant GI bleeding, especially in patients with AF who are receiving OAC for stroke prevention. OCT has been shown to minimize recurrent GI bleeds related to AVMs. METHODS: In a multicenter, observational study, 38 AF patients with contraindications to OAC because of AVM-related GI bleeding were started on 100 µg of subcutaneous OCT twice daily. OAC was resumed in all patients within 48 h. Incidence of recurrent GI bleeds was calculated, and hemoglobin levels were recorded at enrollment and at 3 and 6 months' follow-up. RESULTS: After a median follow-up of 8 months, 36 patients (mean age 69 ± 8.0 years; mean CHA2DS2-VASc score 3 ± 1 and mean HAS-BLED score 3 ± 1) were available for analysis. All were able to successfully resume OAC, and 28 of 36 (78%) remained on OAC at the conclusion of the study, whereas 8 underwent left atrial appendage closure with subsequent OAC discontinuation. No systemic thromboembolic events occurred in follow-up. Of the 28 patients who continued receiving OAC, 19 (68%) were free of recurrent GI bleed, 4 had minor GI bleeds, 4 required transfusion, and 1 required colectomy for GI bleeding. Mean hemoglobin levels in all patients receiving OAC were significantly higher at 3- and 6-month follow-up than at baseline (p < 0.001). CONCLUSIONS: Subcutaneous OCT therapy is an attractive option in AF patients receiving OAC who have AVM-related GI bleeds. It allows successful reinitiation of OAC as a bridge to left atrial appendage exclusion or short-term relief from bleeding.

Safety and Efficacy of Inpatient Initiation of Dofetilide versus Sotalol for atrial fibrillation.

BACKGROUND: We sought to investigate and compare the safety and efficacy of two commonly used antiarrhythmic drugs, Dofetilide (DF) and Sotalol (SL), during inpatient drug initiation in patients with symptomatic atrial fibrillation (AF). METHODS: We performed a single center retrospective study of consecutive patients, admitted for initiation of either DF or SL, for AF between 2012 and 2015. Rates of successful cardioversion, QT interval prolongation, adverse events and drug discontinuations were calculated and compared. A two-tailed p value less than 0.05 was considered statistically significant. RESULTS: Of 378 patients, 298 (78.8%) received DF and 80 (21.2%) SL, mean age was 64 ± 11 years, 90% were Caucasians and 66% were males. Among the patients who remained in AF upon admission (DF: 215/298 (72%) vs. SL: 48/80 (60%)), no significant differences were noted in pharmacological cardioversion rates (DF: 125/215(58%) vs. SL: 30/48 (62.5%); p = 0.58). Baseline QTc was similar between the groups, with higher dose dependent QTc prolongation with DF (472.25± 31.3 vs. 458± 27.03; p = 0.008). There were no significant differences in the rates of adverse events such as bradycardia (7.4% vs. 11.3%; p = 0.26), Torsades de pointes (1.3% vs. 1.2%; p = 1.00), and drug discontinuation (9.0% vs. 5.0%; p = 0.47) between the two groups.

Catheter Ablation for Atrial Fibrillation in Patients With Watchman Left Atrial Appendage Occlusion Device: Results from a Multicenter Registry.

BACKGROUND: There have been an increasing number of atrial fibrillation (AF) patients with Watchman left atrial appendage occlusion (LAAO) device, requiring catheter ablation (CA) for maintenance of normal sinus rhythm. In this study, we describe our experience with the feasibility and safety of CA in patients with a preexisting Watchman LAAO device. METHODS: This was a retrospective multicenter AF registry of 60 patients with Watchman LAAO device who underwent CA for AF. Baseline clinical and procedural characteristics of the included subjects were retrieved from review of medical records and were analyzed. RESULTS: The mean age was 72.7 ± 4.9 years and the mean CHADS2 score was 2.3 ± 0.6. All patients had successful pulmonary vein isolation (PVI). The left atrial appendage (LAA) was electrically active in 34 (56%) while reentrant tachycardia and AF triggers were seen in 17 (28%) patients. Electrical isolation was attempted in these 17 patients with only 10 achieving complete LAA isolation. Repeat imaging showed new peri-device leaks in 30% (12/40) patients, while new significant peri-device leaks (≥5 mm) were noted in 10% (10/40) of patients after RFA, respectively, requiring continuation of oral anticoagulation. There were a higher proportion of patients with severe peri-device leaks (≥5 mm) after LAA isolation. However, >50% of those leaks sealed off on follow-up transesophageal echocardiogram. CONCLUSION: AF ablation is a feasible and safe in patients with preexisting Watchman LAAO device. Electrical isolation of the LAA could be difficult and when attempted can result in increased risk of short-term peri-device leak and recurrence of AT/AF in almost all patients.

Partial Brain Tissue Oxygen Levels Predict Arrhythmia and Prognosis in Patients With Brain Injury.

The objective of this study was to examine the clinical determinants of incidence and prognosis of arrhythmias in the setting of acute brain injury. Acute brain injury is known to cause electrocardiographic abnormalities and cardiac arrhythmias. The relation between partial brain tissue oxygen (PBTO) and intracranial pressure (ICP) with arrhythmia incidence and prognosis remains unknown. Consecutive patients with acute brain injury and intracranial bleed admitted to the neurosurgical intensive care unit were enrolled in the study. Baseline characteristics [demographics, medical history, etiology of brain injury, Glasgow Coma Scale (GCS) score, blood pressure, and respiratory rate] were documented. Patient's telemetry recordings were reviewed for daily mean heart rates and arrhythmias. If arrhythmia was noted, PBTO levels at the beginning of arrhythmia, ICP, brain tissue temperature, and outcomes were recorded. A total of 106 subjects (53% men, age 39 ± 18 years, 65 traumatic and 41 nontraumatic brain injuries) were studied. Overall, 62% of subjects developed a total of 241 arrhythmia episodes. Ventricular arrhythmias were associated with significantly higher daily mean heart rates, low PBTO levels, and low GCS scores, whereas atrial arrhythmias were associated with lower daily mean heart rates, normal PBTO levels, and higher GCS and ICP. Three or more episodes of arrhythmia predicted worse outcomes, including mortality (P = 0.001). In patients with acute brain injury, poor PBTO levels are associated with higher incidence of ventricular tachyarrhythmias. In contrast, atrial tachyarrhythmias occur in patients with normal PBTO levels and higher ICP. Incidence of ventricular arrhythmia in those with poor PBTO is associated with increased mortality.

Short and long-term outcomes of percutaneous left atrial appendage suture ligation: Results from a US multicenter evaluation.

BACKGROUND: Published studies of epicardial ligation of left atrial appendage (LAA) have reported discordant results. OBJECTIVE: The purpose of this study was to delineate the safety and efficacy of LAA closure with the LARIAT device. METHODS: This is a multicenter registry of 712 consecutive patients undergoing LAA ligation with LARIAT at 18 US hospitals. The primary end point was successful suture deployment, no leak by intraprocedural transesophageal echocardiography (TEE), and no major complication (death, stroke, cardiac perforation, and bleeding requiring transfusion) at discharge. A leak of 2-5 mm on follow-up TEE was the secondary end point. RESULTS: LARIAT was successfully deployed in 682 patients (95.5%). A complete closure was achieved in 669 patients (98%), while 13 patients (1.8%) had a trace leak (<2 mm). There was 1 death related to the procedure. Ten patients (1.44%) had cardiac perforation necessitating open heart surgery, while another 14 (2.01%) did not need surgery. The risk of cardiac perforation decreased significantly after the introduction of a micropuncture (MP) needle for pericardial access. Delayed complications (pericarditis requiring >2 weeks of treatment with nonsteroidal anti-inflammatory drugs/colchicine and pericardial and pleural effusion after discharge) occurred in 34 (4.78%) patients, and the risk decreased significantly with the periprocedural use of colchicine. Follow-up TEE (n = 480) showed a leak of 2-5 mm in 6.5% and a thrombus in 2.5%. One patient had a leak of >5 mm. CONCLUSION: LARIAT effectively closes the LAA and has acceptable procedural risks with the evolution of the use of the micropuncture needle for pericardial access and the use of colchicine for mitigating the postinflammatory response associated with LAA ligation and pericardial access.

Impact of Tricuspid Regurgitation on the Success of Atrioventricular Node Ablation for Rate Control in Patients With Atrial Fibrillation: The Node Blast Study.

Atrioventricular node (AVN) ablation is an effective treatment for symptomatic patients with atrial arrhythmias who are refractory to rhythm and rate control strategies where optimal ventricular rate control is desired. There are limited data on the predictors of failure of AVN ablation. Our objective was to identify the predictors of failure of AVN ablation. This is an observational single-center study of consecutive patients who underwent AVN ablation in a large academic center. Baseline characteristics, procedural variables, and outcomes of AVN ablation were collected. AVN "ablation failure" was defined as resumption of AVN conduction resulting in recurrence of either rapid ventricular response or suboptimal biventricular pacing. A total of 247 patients drug refractory AF who underwent AVN ablation at our center with a mean age of 71 ± 12 years with 46% being males were included. Ablation failure was seen in 11 (4.5%) patients. There were no statistical differences between patients with "ablation failure" versus "ablation success" in any of the baseline clinical variables. Patients with moderate-to-severe tricuspid regurgitation (TR) were much more likely to have ablation failure than those with ablation success (8 [73%] vs 65 [27%]; p = 0.003). All 11 patients with ablation failure had a successful redo procedure, 9 with right and 2 with the left sided approach. On multivariate analysis, presence of moderate-to-severe TR was found to be the only predictor of failure of AVN ablation (odds ratio 9.1, confidence interval 1.99 to 42.22, p = 0.004). In conclusion, moderate-to-severe TR is a strong and independent predictor of failure of AVN ablation.

Initial real world experience with a novel insertable (Reveal LinQ(@Medtronic)) compared to the conventional (Reveal XT(@Medtronic)) implantable loop recorder at a tertiary care center - Points to ponder!

INTRODUCTION: Limited data is available regarding the novel Reveal LinQ (LinQ) which is a new generation implantable loop recorders (ILRs). METHODS: We performed a prospective, observational study of all consecutive patients undergoing conventional (Reveal XT; XT) and LinQ devices at our institution between January 2012 and December 2014. RESULTS: A total of 217 patients underwent ILR implantation. XT was implanted in 105 and LinQ in 112 patients. There were no significant differences in baseline characteristics between the two groups. LinQ implantation using the manufacturer's technique termed, "manufacturer's method" group had significantly higher incidence of pocket infection compared to XT (6/50, 12% vs 3/105, 3%, p=0.032). With modifications to the LinQ implantation technique (using a conventional scalpel and placing a suture when needed to the incision) termed "modified method" group, the rate of infection has decreased significantly compared to "manufacturer's method group" (0/62, 0% vs 6/50, 12%, p=0.004) (Table 3). In multivariate regression analysis, the only independent predictors of infection were younger age (OR 0.95; p=0.04), insertion of LinQ device (OR 30.02; p=0.006) and procedure time (OR 1.07; p=0.03). CONCLUSION: In our single-center, prospective, observational study we found that with the current implantable techniques, the novel insertable LinQ device is associated with increased risk of complications.

Electrolyte and hemodynamic changes following percutaneous left atrial appendage ligation with the LARIAT device.

PURPOSE: The left atrial appendage (LAA) is a well-known source of atrial natriuretic peptide (ANP) and therefore plays an important role in homeostasis. The neurohormonal impact of epicardial exclusion of the LAA with the LARIAT procedure is unknown. In this proof-of-concept study, we postulated that LAA exclusion would impact homeostasis as evidenced by changes in electrolytes and blood pressure (BP). METHODS: A total of 76 patients who underwent successful LAA exclusion were enrolled in this retrospective observational study utilizing a prospective registry. Electrolytes, BP, and heart rate (HR) were monitored before LARIAT and post-LARIAT (24 and 72 h and 6 months). RESULTS: There was a significant reduction of systolic BP (mmHg) at 24 h (113.3 ± 16.0; p < 0.0001) and 72 h (119.0 ± 18.4 mmHg; p < 0.0001) post-LARIAT when compared with pre-LARIAT BP (138.2 ± 21.3). The reduction in systolic BP persisted at 6-month follow-up (128.8 ± 17.3; p = 0.0005). There was significant reduction in serum sodium (mmol/L) at 24 h (135.4 ± 3.6; p < 0.0001) and 72 h (136.3 ± 3.7; p < 0.001) post-LARIAT when compared to pre-LARIAT (138.7 ± 3.2). The reduction in sodium was not persistent at 6-month follow-up (138.4 ± 3.3; p = 0.453). CONCLUSIONS: LAA exclusion results in an early and persistent decrease in systolic BP. Additionally, there is an early decline in serum sodium, which normalizes at long-term follow-up. The underlying mechanism leading to these changes is not entirely clear; however, it is likely related to neurohormonal changes post LAA exclusion.

Under-Utilization of Implantable Cardioverter Defibrillators in Patients with Heart Failure - The Current State of Sudden Cardiac Death Prophylaxis.

BACKGROUND: Despite ACC/AHA guidelines indicating implantable cardioverter defibrillator (ICD) as class I therapy for primary prevention of sudden cardiac death in patients with EF≤35%, ICD utilization rates in real world practice have been low. OBJECTIVE: To determine the rate of ICD implantation at a tertiary care academic center and to assess the reasons for under-utilization of the same. METHODS: Review of a prospectively collected database which included all patients diagnosed with an EF≤35% was performed to assess the rate of ICD implantation and mortality. Reasons for non-implantation of ICD were then assessed from detailed chart review. RESULTS: A total of 707 patients (age 69.4 ± 14.1 years) with mean EF of 26±7% were analyzed. Only 28% (200/707) of patients had ICDs implanted. Mortality was lower in the group with ICD (25% vs 37%, p=0.004). When patients who either died or were lost to follow-up prior to 2005 were excluded, ICD utilization rate was still low at 37.6%. The most common reason for non-implantation of ICD was physicians not discussing this option with their patients. Patient refusal was the second most common reason. CONCLUSIONS: ICD Implantation rates for primary prevention of SCD in patients with EF≤35% is low. Physician and patient education should be addressed to improve the utilization rates.