Cardiac device-induced right to left shunt causing significant hypoxemia: A case report and review of literature.

We describe a patient where a pacemaker lead induced tricuspid valve changes that caused a right to left shunt through a preexisting patent foramen ovale resulting in significant hypoxemia. This event occurred years after the pacemaker had been placed. Surgical closure of the patent foramen ovale resolved the patient's hypoxemia and dyspnea. We also reviewed the previous cases published in the medical literature concerning significant hypoxemia from cardiac device-induced right to left shunts. Three of the four reported cased occurred 4 or more years after device placement. Therefore, late onset hypoxemia in setting of cardiac device placement without an alternative cause should raise the possibility of this complication.

Outcomes of prednisone-tapering regimens for cardiac sarcoidosis: A retrospective analysis demonstrating a benefit of infliximab.

BACKGROUND: The optimal treatment strategy for cardiac sarcoidosis has not been standardized. We examined the effectiveness of three prednisone-tapering treatment regimens for cardiac sarcoidosis. METHODS: We retrospectively reviewed prednisone-tapering treatment regimens for cardiac sarcoidosis that contained prednisone alone (P), prednisone plus methotrexate (P-M), and prednisone plus infliximab containing regimens (P-I). We defined the success of each regimen as the ability to lower the daily prednisone dose to 7.5 mg or less for 6 or more months without developing an adverse cardiac event. We also examined the lowest effective daily prednisone dose achieved without developing an adverse cardiac event. RESULTS: We identified 61 treatment regimens in 33 cardiac sarcoidosis patients that were analyzed. The success rate of prednisone-tapering regimens was significantly different P: 8/30, 27%; P-M: 3/23, 13%; P-I: 6/8, 75%., p = 0.04. The lowest effective daily prednisone dose for the regimens was also significantly different: P: 14.1 ± 10.1 mg; P-M: 16.9 ± 9.4 mg; infliximab: 7.8 ± 4.9 mg, (p = 0.03); by both measures the success was greatest with the P-I regimen. CONCLUSIONS: For the treatment of cardiac sarcoidosis, prednisone-tapering regimens containing infliximab are superior to those containing prednisone alone or prednisone plus methotrexate in terms of reaching 7.5 mg/day of prednisone for more than 6 months and achieving the lowest effective prednisone.

Increased incidence of electrical abnormalities in a pacemaker lead family.

INTRODUCTION: Several recent studies have raised concern about noise detections on Tendril pacemaker leads, which may represent insulation failure or algorithm-driven overreporting of physiologic signals. METHODS: We identified all pacemaker leads actively followed at Albany Medical Center, of which 1111 leads (262 Abbott Tendril, 576 Medtronic CapSure, 30 Fineline, 195 Ingevity, 48 Dextrus) in 703 patients were included in this observational study. Electrical abnormalities, comprising low-impedance measurements <200 Ω and repeated noise detections, were catalogued, as was initial management and subsequent need for surgical intervention. RESULTS: During 54 months median follow-up (interquartile range 24-105), 63 leads (5.7%) demonstrated electrical abnormalities, including low impedances in 21 and noise in 59. Tendril leads manifested abnormalities most frequently (n = 50; 19.1%) compared with CapSure (n = 9; 1.6%), Fineline (n = 0), Ingevity (n = 0), and Dextrus (n = 4; 8.3%) leads. The risk of abnormalities was significantly higher in Tendril leads (HR 9.6, 95% CI 5.2-17.6; p < .001). Low impedances were measured on 19 Tendril leads, a significantly higher risk than on other leads (HR 23.8, 95% CI 5.5-102.1; p < .001). Although observation and reprogramming sensitivity were the initial management strategy for 45 and 7 leads, respectively, 18 ultimately required surgical intervention, including 15 Tendrils. No electrical abnormalities were observed in 12 non-Tendril leads attached to Abbott devices compared with 48 of 252 Tendrils attached to Abbott devices (log-rank p = .035). CONCLUSION: Tendril leads demonstrate significantly higher risk of repeated low impedances and noise compared to other manufacturers' models, raising concern that these findings reflect early insulation failure. Increased scrutiny is warranted.

Severe chronic kidney disease is associated with poor survival after initial CRT-defibrillator tachyarrhythmia therapy.

BACKGROUND: Implantable cardioverter-defibrillator (ICD) recipients who receive appropriate device therapies have limited survival, and survival benefit in chronic kidney disease (CKD) has been questioned. We examined the association between CKD and survival after cardiac resynchronization therapy (CRT)-defibrillator tachyarrhythmia therapies. METHODS: We compared overall survival after appropriate shocks or anti-tachycardia pacing in 439 CRT-defibrillator recipients with left ventricular ejection fraction (LVEF) ≤35%, non-right bundle-branch block QRS pattern, and QRS duration >130 ms according to glomerular filtration rate (GFR) at implant, including 31 patients with GFR ≤30, 164 patients with GFR 31-60, and 244 patients with GFR >60. At least one shock occurred in 302 patients (24 with GFR ≤30, 102 with GFR 31-60, and 176 with GFR >60). Serial echocardiograms were also compared. RESULTS: Patients were followed 64 months (interquartile range [IQR]: 29-94) after implant, including 32 months (IQR: 12-61) after first therapy. Time to first therapy or shock was similar across GFR groups. However, survival after first therapy declined directly with declining GFR (P < .001), with median postshock survival of 90 days for GFR ≤30 (95% confidence of interval [CI]: 0-233), 612 days (95% CI: 365-859) for GFR 31-60, and 1672 days (95% CI: 1396-1948) for GFR >60. Declining GFR category, ischemic heart disease, diabetes, and increasing age were independently associated with increased postshock mortality. Echocardiographic response was similar across GFR groups and was not associated with post-therapy survival. CONCLUSIONS: Survival after appropriate tachyarrhythmia therapies, particularly shocks, is attenuated in patients with GFR ≤30. This raises concern over potential lack of survival benefit conferred by CRT-defibrillators versus CRT-pacemakers in this population.

Implications of Neurological Status on Defibrillator Therapy and Long-Term Mortality of Sudden Cardiac Arrest Survivors.

OBJECTIVES: This study sought to investigate the impact of the neurological status of sudden cardiac arrest (SCA) survivors on implantable cardioverter-defibrillator (ICD) insertion and long-term mortality. BACKGROUND: The neurological status of SCA survivors may impact the decision to insert an ICD insertion and influence long-term survival. METHODS: In 1,433 survivors of SCA between 2002 and 2012, we examined the neurological status immediately after the arrest using the Pittsburgh Cardiac Arrest Category (PCAC) and prior to hospital discharge using the cerebral performance category (CPC) score. Patients were followed up to the endpoints of ICD implantation and all-cause mortality. RESULTS: Over a median follow-up period of 3.6 years, 389 (27%) patients received an ICD, and 674 (47%) died. The PCAC (adjusted hazard ratio [HR]: 0.79; 95% confidence interval [CI]: 0.69 to 0.90) and CPC (adjusted HR: 0.73; 95% CI: 0.64 to 0.84) scores were highly predictive of the time to ICD insertion and of all-cause mortality (PCAC score, adjusted HR: 1.39; 95% CI: 1.24 to 1.57; CPC score, adjusted HR: 2.03; 95% CI: 1.77 to 2.34). ICD therapy was associated with better survival even after adjusting for neurological status (HR: 0.56; 95% CI: 0.43 to 0.73). A significant proportion of patients in the worse CPC categories had a >1-year survival after the index SCA. CONCLUSIONS: In SCA survivors, worse neurological performance was associated with lower likelihood of ICD insertion and higher mortality. ICD insertion was associated with improved survival even after accounting for neurological performance. ICD discussion should therefore not be omitted in these patients.

Oral Anticoagulation for Atrial Fibrillation Thromboembolism Prophylaxis in the Chronic Kidney Disease Population: the State of the Art in 2019.

Atrial fibrillation (AF) is the most common cardiac rhythm disturbance and is associated with increased risk of thromboembolism. Oral anticoagulants are effective at reducing rates of thromboembolism in patients with AF in the general population. Patients with AF and concurrent chronic kidney disease (CKD) have higher risk of thromboembolism and bleeding compared with patients with normal renal function. Among moderate CKD and end-stage renal disease (ESRD) patients on chronic dialysis, the use of oral anticoagulants is controversial. Use of warfarin, while beneficial in non-CKD patients, raises a number of concerns such as increased bleeding risk, labile anticoagulant effect, and calciphylaxis, especially in the ESRD population. The newer direct oral anticoagulant (DOAC) agents have demonstrated comparable efficacy and improved safety profiles compared with coumadin but are not as well studied in the CKD population. This review highlights the efficacy and safety of coumadin and the DOACs for thromboembolism prophylaxis in non-valvular AF patients with CKD.

Trends in Hospital Admissions for and Readmissions After Cardiac Implantable Electronic Device Procedures in the United States: An Analysis From 2010 to 2014 Using the National Readmission Database.

OBJECTIVE: To evaluate inpatient trends in de novo complete cardiac implantable electronic device (CIED) procedures and subsequent all-cause 30-day readmissions in the United States. PATIENTS AND METHODS: We accessed the National Readmission Database to identify CIED implantation-related hospitalizations between January 1, 2010, and December 31, 2014, using International Classification of Diseases, Ninth Revision, Clinical Modification procedure codes. In-hospital mortality and postprocedure all-cause 30-day readmissions were also analyzed. RESULTS: During the study period, a total of 800,250 CIED implantation hospitalizations were identified across the United States, with an in-hospital mortality rate of 0.9% (7423 of 800,250) and a 29% decrease in CIED-related index hospitalizations (188,086 in 2010 vs 134,276 in 2014). The all-cause 30-day readmission rate for the entire cohort was 13% (106,505 of 800,250), decreasing from 14% (26,134 of 188,085) in 2010 to only 13% (17,154 of 134,276) by 2014. Dual-chamber pacemakers were the most frequently implanted in-hospital CIEDs (473,615 of 800,250 [59%]). The most common cause for readmission was heart failure exacerbation, which remained unchanged over the study period. CONCLUSION: Our data reveal a steady decline in overall in-hospital CIED implantations and only a modest decline in readmission rates. The cause for this decline may be an impact of medical and regulatory changes guiding CIED implantations, but it deserves further investigation.

Sex-specific clinical outcomes after cardiac resynchronization therapy in left bundle branch block-associated idiopathic nonischemic cardiomyopathy: A NEOLITH II substudy.

BACKGROUND: Sex differences in clinical outcomes for left bundle branch block (LBBB)-associated idiopathic nonischemic cardiomyopathy (NICM) after cardiac resynchronization therapy (CRT) are not well described. METHODS: A retrospective cohort study at an academic medical center included subjects with LBBB-associated idiopathic NICM who received CRT. Cox regression analyses estimated the hazard ratios (HRs) between sex and clinical outcomes. RESULTS: In 123 total subjects (mean age 62 years, mean initial left ventricular ejection fraction 22.8%, 76% New York Heart Association class III, and 98% CRT-defibrillators), 55 (45%) were men and 68 (55%) were women. The median follow-up time after CRT was 72.4 months. Similar risk for adverse clinical events (heart failure hospitalization, appropriate implantable cardioverter-defibrillator shock, appropriate antitachycardia pacing therapy, ventricular assist device implantation, heart transplantation, and death) was observed between men and women (HR, 1.20; 95% confidence interval [CI] 0.57-2.51; p = 0.63). This persisted in multivariable analyses. Men and women had similar risk for all-cause mortality in univariable analysis, but men had higher risk in the final multivariable model that adjusted for age at diagnosis, QRS duration, and left ventricular end-diastolic dimension index (HR, 4.55; 95% CI, 1.26-16.39; p = 0.02). The estimated 5-year mortality was 9.5% for men and 6.9% for women. CONCLUSIONS: In LBBB-associated idiopathic NICM, men have higher risk for all-cause mortality after CRT when compared to women.

Characterization of pulmonary vein reconnection post Cryoballoon ablation.

BACKGROUND: The Arctic Front Cryoballoon System is a technology in which substrate alterations in patients with atrial fibrillation (AF) recurrence have not been well characterized. In this study, we evaluated sites of pulmonary vein (PV) reconnections and the accuracy of the Achieve™ circular mapping catheter in detecting these reconnections after cryoablation. METHODS: This study included 15 patients undergoing redo AF ablation after a prior single cryoablation procedure. PV reconnection sites were determined by measuring PV signals and high output pacing from 4 vectors of the Achieve catheter. The results were compared with a roving mapping catheter guided by rotational intracardiac echocardiography (ICE) in the left atrium. RESULTS: All patients had PV reconnections (2.1 ±â€¯0.8 veins/patient). The left superior PV was most commonly reconnected (n = 11), whereas the right inferior PV was least likely (n = 3). Both carinas (left: n = 11; right: n = 7) and left atrial appendage ridge (n = 11) were also frequently reconnected. Mapping with the Achieve catheter showed a positive predictive value (PPV) 100% and negative predictive value (NPV) 96% when compared with ICE guided mapping. In 2 patients, right superior PV reconnection was not identified by the Achieve. CONCLUSION: During redo AF ablation after index cryoablation, multiple PVs are usually reconnected, with both carinas and left atrial appendage ridge being common sites of reconnection. The Achieve mapping catheter was able to identify reconnection with high positive and negative predictive values.

Wearable Cardioverter-Defibrillator Therapy for the Prevention of Sudden Cardiac Death: A Systematic Review and Meta-Analysis.

OBJECTIVES: This study sought to synthesize the available evidence on the use of the wearable cardioverter-defibrillator (WCD). BACKGROUND: Observational WCD studies for the prevention of sudden cardiac death have provided conflicting data. The VEST (Vest Prevention of Early Sudden Death) trial was the first randomized controlled trial (RCT) showing no reduction in sudden cardiac death as compared to medical therapy only. METHODS: We searched PubMed, EMBASE, and Google Scholar for studies reporting on the outcomes of patients wearing WCDs from January 1, 2001, through March 20, 2018. Rates of appropriate and inappropriate WCD therapies were pooled. Estimates were derived using DerSimonian and Laird's method. RESULTS: Twenty-eight studies were included (N = 33,242; 27 observational, 1 RCT-WCD arm). The incidence of appropriate WCD therapy was 5 per 100 persons over 3 months (95% confidence interval [CI]: 3.0 to 6.0, I2 = 93%). In studies on ischemic cardiomyopathy, the appropriate WCD therapy incidence was lower in the VEST trial (1 per 100 persons over 3 months; 95% CI: 1.0 to 2.0) as compared with observational studies (11 per 100 persons over 3 months; 95% CI: 11.0 to 20.0; I2 = 93%). The incidence of inappropriate therapy was 2 per 100 persons over 3 months (95% CI: 1.0 to 3.0; I2 = 93%). Mortality while wearing WCD was rare at 0.7 per 100 persons over 3 months (95% CI: 0.3 to 1.7; I2 = 94%). CONCLUSIONS: The rate of appropriately treated WCD patients over 3 months of follow-up was substantial; higher in-observational studies as compared with the VEST trial. There was significant heterogeneity. More RCTs are needed to justify continued use of WCD in primary prevention.

Amiodarone is associated with adverse outcomes in patients with sustained ventricular arrhythmias upgraded to cardiac resynchronization therapy-defibrillators.

INTRODUCTION: Amiodarone reduces recurrent ventricular tachyarrhythmias (VTA) but may worsen cardiovascular outcomes in heart failure (HF) patients. Cardiac resynchronization therapy (CRT) may also be antiarrhythmic. When patients with prior sustained VTA are upgraded to CRT defibrillators (CRT-D) from conventional implantable cardioverter-defibrillators (ICDs), should concomitant amiodarone be continued or is CRT's antiarrhythmic potential sufficient? METHODS AND RESULTS: We identified 67 patients from a prospective CRT registry with spontaneous sustained VTA, New York Heart Association (NYHA) II-IV HF, and left bundle-branch block (LBBB) who were upgraded to CRT defibrillators from conventional ICDs. We compared changes in QRS duration and left ventricular ejection fraction (LVEF) pre- and post-CRT, time to death, transplant or ventricular assist device (VAD), and time to recurrent VTA therapies between 37 patients continuing amiodarone therapy and 30 amiodarone-naïve patients. Amiodarone-treated patients had worse renal function and a higher prevalence of prior VTA storm compared with amiodarone-naïve patients. After CRT, amiodarone-treated patients demonstrated less QRS narrowing (8 vs 20 ms; P = 0.021) and less LVEF improvement (-2.7 vs +5.2%; P = 0.006). Over 29 months, 31 (47%) patients died and 13 (20%) received transplant or VAD. Risk of death, transplant, or VAD was greater in amiodarone-treated than -naïve patients (corrected hazard ratio [HR], 2.14; 95% confidence interval [CI], 1.12-4.11; P = 0.022). Appropriate CRT-D therapies occurred in 37 (55%) patients; amiodarone use was not associated time to first therapy (HR, 1.13; 95% CI, 0.59-2.16; P = 0.72). CONCLUSION: In patients with sustained VTA and LBBB upgraded from conventional ICDs to CRT defibrillators, concomitant amiodarone use is associated with less QRS narrowing, less LVEF improvement, greater risk of death, transplant, or VAD, and similar risk of recurrent VTA.

Myocardial recovery after cardiac resynchronization therapy in left bundle branch block-associated idiopathic nonischemic cardiomyopathy: A NEOLITH II substudy.

BACKGROUND: Baseline predictors of myocardial recovery after cardiac resynchronization therapy (CRT) in left bundle branch block (LBBB)-associated idiopathic nonischemic cardiomyopathy (NICM) are unknown. METHODS: A retrospective study included subjects with idiopathic NICM, left ventricular ejection fraction (LVEF) ≤35%, and LBBB. Myocardial recovery was defined as post-CRT LVEF ≥50%. Logistic regression analyses described associations between baseline characteristics and myocardial recovery. Cox regression analyses estimated the hazard ratio (HR) between myocardial recovery status and adverse clinical events. RESULTS: In 105 subjects (mean age 61 years, 44% male, mean initial LVEF 22.6% ± 6.6%, 81% New York Heart Association class III, and 98% CRT-defibrillators), myocardial recovery after CRT was observed in 56 (54%) subjects. Hypertension, heart rate, and serum blood urea nitrogen (BUN) had negative associations with myocardial recovery in univariable analyses. These associations persisted in multivariable analysis: hypertension (odds ratio (OR), 0.40; 95% confidence interval (CI), 0.17-0.95; p = 0.04), heart rate (OR per 10 bpm, 0.69; 95% CI, 0.48-0.997; p = 0.048), and serum BUN (OR per 1 mg/dl, 0.94; 95% CI, 0.88-0.99; p = 0.04). Subjects with post-CRT LVEF ≥50%, when compared to <50%, had lower risk for adverse clinical events (heart failure hospitalization, appropriate implantable cardioverter-defibrillator shock, appropriate anti-tachycardia pacing therapy, ventricular assist device implantation, heart transplantation, and death) over a median follow-up of 75.9 months (HR, 0.38; 95% CI, 0.16-0.88; p = 0.02). CONCLUSION: In LBBB-associated idiopathic NICM, myocardial recovery after CRT was associated with absence of hypertension, lower heart rate, and lower serum BUN. Those with myocardial recovery had fewer adverse clinical events.

Improvement in ejection fraction after cryoballoon pulmonary vein isolation for atrial fibrillation in individuals with systolic dysfunction.

BACKGROUND: Cryoballoon pulmonary vein isolation (PVI) is commonly used for rhythm control of atrial fibrillation (AF). Data are limited examining the outcomes of cryoballoon PVI in patients with systolic dysfunction. We evaluate the impact of cryoballoon PVI in patients with systolic dysfunction. METHODS: We evaluated a single-center prospective registry of patients undergoing cryoballoon PVI between 8/2011 and 6/2016. Patients with systolic dysfunction (EF < 55%) between the time of AF diagnosis and their cryoballoon PVI procedure were assessed for AF recurrence at 6 months and 1 year post-procedure, with a 3-month blanking period. RESULTS: Final analysis included 66 patients with systolic dysfunction undergoing cryoballoon PVI. An AF diagnosis for ≥ 1 year prior to PVI was present in 62.1% (n = 41), and 53.0% (n = 35) had systolic dysfunction for ≥ 1 year pre-procedure. The proportion of AF-free patients at 1 year was 51.5%. Of patients with echocardiograms performed at 1 year (n = 43), a greater proportion of individuals without AF recurrence had an improvement in EF of ≥ 10% than in those with AF recurrence (54.2% vs. 25.0%, p = 0.039). Of the patients who had systolic dysfunction at the time of the ablation (EF < 55%), there was a significant increase in EF post-procedure (36.5% pre-procedure vs. 48.3% post-procedure, mean change 11.8%, p < 0.001). CONCLUSION: In patients with systolic dysfunction, cryoballoon PVI provides an acceptable AF recurrence-free rate at 1 year. AF recurrence-free individuals were more likely to have improvement in EF. Further evaluation is needed to determine the potential role of early cryoballoon PVI in patients with a new diagnosis of systolic dysfunction and AF.

Implantable cardioverter-defibrillator therapy in device recipients who survived a cardiac arrest associated with a reversible cause.

BACKGROUND: Guideline recommendations for implantable cardioverter-defibrillators (ICD) for secondary prevention of sudden cardiac arrest (SCA) have excluded patients with reversible causes. We previously demonstrated mortality benefit with the ICD in survivors of SCA associated with reversible causes other than myocardial infarction (MI) or ischemia treated with coronary revascularization. In the current study, we examined the incidence of ICD therapy in patients with SCA related to reversible causes. METHODS: Data were collected for all patients over the age of 18 years who had survived to hospital discharge after SCA between 2002 and 2012. ICD recipients with reversible causes were divided into 2 groups based on their reversible etiology of SCA: MI + ICD (n = 132) and non-MI + ICD (n = 75). Delivered ICD therapy was examined. RESULTS: Over a follow-up period of 3.8 ± 3.1 years, more patients without MI/ischemia who received an ICD experienced appropriate (adjusted HR, 3.96; 95% CI, 1.32-11.84) but not inappropriate (adjusted HR, 0.65; 95% CI, 0.14-2.97) ICD therapy compared with patients without MI/ischemia. The proportion of patients receiving appropriate (P = 0.012) but not inappropriate (P = 0.80) ICD therapy was also higher in the non-MI + ICD compared with the MI + ICD group. CONCLUSION: We show higher rates of appropriate ICD therapy in survivors of SCA associated with reversible causes other than MI/ischemia. This finding, in conjunction with the previously demonstrated lower all-cause mortality noted in the presence of an ICD in SCA survivors with reversible etiology other than MI/ischemia, further supports consideration of ICD implantation in this population.

Scar burden, not intraventricular conduction delay pattern, is associated with outcomes in ischemic cardiomyopathy patients receiving cardiac resynchronization therapy.

BACKGROUND: Patients with nonspecific intraventricular conduction delay (IVCD) benefit less from cardiac resynchronization therapy (CRT) than patients with left bundle branch block (LBBB). OBJECTIVE: The purpose of this study was to determine whether post-CRT outcome differences in patients with ischemic cardiomyopathy (ICM) relate to intrinsic QRS pattern and/or scar burden. METHODS: We analyzed 393 consecutive ICM patients with left ventricular ejection fraction (LVEF) ≤35%, QRS duration >120 ms, and LBBB or nonspecific IVCD who underwent single-photon emission computed tomography myocardial perfusion imaging and CRT-defibrillator implant. We compared scar burden; QRS duration; LVEF change; risk of death, transplant, or ventricular assist device; and risk of appropriate device shocks between LBBB and IVCD patients, using multivariable analyses to determine relative associations between QRS pattern vs scar burden and outcomes. RESULTS: Nonspecific IVCD is associated with greater scar burden and narrower baseline QRS duration than LBBB. IVCD patients demonstrated less QRS narrowing with CRT than LBBB patients, even when excluding IVCD patients with QRS duration <150 ms. LVEF improved less in patients with IVCD vs LBBB, but only scar burden not QRS morphology or duration was associated with LVEF increase ≥5%. During 39-month follow-up, IVCD was associated with shorter survival free from transplant/ventricular assist device and shorter time to first appropriate device shock. Scar burden but not QRS morphology was independently associated with these outcomes on multivariate analysis. CONCLUSION: IVCD is associated with greater scar burden than LBBB in ICM CRT-defibrillator recipients. Scar burden, not QRS pattern, is independently associated with adverse clinical outcomes.

Oral anticoagulation and left atrial thrombi resolution in nonrheumatic atrial fibrillation or flutter: A systematic review and meta-analysis.

BACKGROUND: Oral anticoagulation (OAC) is prescribed for left atrial thrombi (LAT) in nonrheumatic atrial fibrillation (AF) and/or atrial flutter (AFL). The study objective was to review the existing evidence regarding LAT resolution in nonrheumatic AF and/or AFL with OAC agents. METHODS: Data sources included PubMed, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) between January 1, 1991 and February 10, 2017. English-language studies that assessed LAT resolution with OAC agents in subjects with nonrheumatic AF and/or AFL, by serial transesophageal echocardiography, and with follow-up times ≥ 3 weeks and < 1 year, were selected. Study quality was assessed using recommendations adapted from the Agency for Healthcare Research and Quality. Pooled LAT resolution rates were evaluated for vitamin K antagonist (VKA) studies and low risk of bias warfarin studies. RESULTS: The pooled LAT resolution rate of 619 subjects from 16 VKA studies was 63.7% (95% confidence interval [CI], 53.3%-72.9%). The pooled LAT resolution rate of 94 subjects from four studies that specified warfarin use, exclusion of prior long-term therapeutic OAC, and target international normalized ratio (INR) ≥ 2.0 and/or average achieved INR ≥ 2.0 was 79.3% (95% CI, 69.8%-86.4%). Two studies in direct-acting oral anticoagulants (DOACs) reported LAT resolution rates of 89.5% (17 of 19) for dabigatran and 41.5% (22 of 53) for rivaroxaban. CONCLUSIONS: Warfarin is the most studied initial OAC agent for treating LAT in nonrheumatic AF and/or AFL with a resolution rate of nearly 80%. Further studies in DOACs are warranted.

Implantable Defibrillator Therapy in Cardiac Arrest Survivors With a Reversible Cause.

BACKGROUND: Current guidelines recommend implantable cardioverter-defibrillator (ICD) therapy in survivors of sudden cardiac arrest (SCA), except in those with completely reversible causes. We sought to examine the impact of ICD therapy on mortality in survivors of SCA associated with reversible causes. METHODS AND RESULTS: We evaluated the records of 1433 patients managed at our institution between 2000 and 2012 who were discharged alive after SCA. A reversible and correctable cause was identified in 792 (55%) patients. Reversible SCA cause was defined as significant electrolyte or metabolic abnormality, evidence of acute myocardial infarction or ischemia, recent initiation of antiarrhythmic drug or illicit drug use, or other reversible circumstances. Of the 792 SCA survivors because of a reversible and correctable cause (age 61±15 years, 40% women), 207 (26%) patients received an ICD after their index SCA. During a mean follow-up of 3.8±3.1 years, 319 (40%) patients died. ICD implantation was highly associated with lower all-cause mortality (P<0.001) even after correcting for unbalanced baseline characteristics (P<0.001). In subgroup analyses, only patients whose SCA was not associated with myocardial infarction extracted benefit from ICD (P<0.001). CONCLUSIONS: In survivors of SCA because of a reversible and correctable cause, ICD therapy is associated with lower all-cause mortality except if the SCA was because of myocardial infarction. These data deserve further investigation in a prospective multicenter randomized controlled trial, as they may have important and immediate clinical implications.

Effect of body mass index on survival after sudden cardiac arrest.

BACKGROUND: Although elevated body mass index (BMI) is a risk factor for cardiac disease, patients with elevated BMI have better survival in the context of severe illness, a phenomenon termed the "obesity paradox." HYPOTHESIS: Higher BMI is associated with lower mortality in sudden cardiac arrest (SCA) survivors. METHODS: Data were collected on 1433 post-SCA patients, discharged alive from the hospitals of the University of Pittsburgh Medical Center between 2002 and 2012. Of those, 1298 patients with documented BMI during the index hospitalization and follow-up data constituted the study cohort. RESULTS: In the overall cohort, 30 patients were underweight (BMI <18.5 kg/m2 ), 312 had normal weight (BMI 18.5-24.9 kg/m2 ), 417 were overweight (BMI 25.0-29.9 kg/m2 ), and 539 were obese (BMI ≥30 kg/m2 ). As expected, the prevalence of coronary artery disease, myocardial infarction, diabetes mellitus, and hypertension increased significantly with increasing BMI. Over a median follow-up of 3.6 years, 602 (46%) patients died. Despite higher prevalence of cardiovascular comorbidities in more obese patients, a higher BMI was associated with lower all-cause mortality on univariate analysis (hazard ratio: 0.86 per increase by 1 BMI category, 95% confidence interval: 0.78-0.94, P = 0.002) and multivariate analysis after adjusting for unbalanced baseline comorbidities (hazard ratio: 0.86 per increase by 1 BMI category, 95% confidence interval: 0.77-0.96, P = 0.009). CONCLUSIONS: Higher BMI is associated with lower all-cause mortality in survivors of SCA, suggesting that the obesity paradox applies to the post-arrest population. Further investigation into its mechanisms may inform the management of post-SCA patients.