Efficacy of Commonly Used 3D Mapping Systems in Acute Success Rates of Catheter Ablation Procedures.

Introduction: This systematic review aims to summarize the procedural arrhythmia termination rates in catheter ablation (CA) procedures of atrial or ventricular arrhythmias using the commonly used mapping systems (CARTO, Rhythmia and EnSite/NavX). Materials and Methods: A systematic search in MEDLINE and Cochrane databases through February 2021 was performed. Results: With regard to atrial fibrillation ablation procedures, acute success rates ranged from 15.4 to 96.0% and 9.1 to 100.0% using the CARTO and EnSite/NavX mapping systems, respectively; acute atrial tachycardia (AT) termination to sinus rhythm ranged from 75 to 100% using the CARTO system. The acute success rate for different types of AT ranged from 75 to 97% using Rhythmia, while the NavX mapping system was also found to have excellent efficacy in the setting of AT, with acute arrhythmia termination rates ranging from 73 to 99%. With regard to ventricular tachycardia, in the setting of ischaemic cardiomyopathy, acute success rates ranged from 70 to 100% using CARTO and 64% using EnSite/NavX systems. The acute success rate using the Rhythmia system ranged from 61.5 to 100.0% for different clinical settings. Conclusions: Mapping systems have played a crucial role in high-density mapping and the observed high procedural success rates of atrial and ventricular CA procedures. More data are needed for the comparative efficacy of mapping systems in acute arrhythmia termination, across different clinical settings.

Incidence and Predictors for Recurrence of Ventricular Arrhythmia Presenting During Acute Myocarditis: A Multicenter Study.

BACKGROUND: Management of acute myocarditis (AM) patients experiencing ventricular arrhythmia (VA) during acute illness is controversial, especially regarding early implantable cardioverter-defibrillator (ICD) implantation. OBJECTIVES: The purpose of this study was to evaluate the prevalence of and find predictors for long-term sustained VA recurrence and overall mortality among AM patients with VA. METHODS: This was a multicenter retrospective analysis of AM patients (verified by cardiac magnetic resonance imaging or myocardial biopsy) with documented VA during the acute illness ("initial VA"). Patients with history of myocardial infarction, heart failure, or VA were excluded. The study endpoint was a composite of sustained VA and overall mortality during follow-up. RESULTS: The study included 69 AM patients with initial VA: sustained monomorphic ventricular tachycardia (MMVT) (n = 25), sustained polymorphic ventricular tachycardia (VT)/ventricular fibrillation (n = 13), and nonsustained VT (n = 31). Age was 44 ± 13 years, and 23 of 69 (33.3%) were women. During median follow-up of 5.5 years, 27 of 69 (39%) patients reached the composite endpoint including sustained VA (n = 24) and death (n = 11). Initial MMVT, predischarge left ventricular dysfunction (left ventricular ejection fraction <50%), and anteroseptal delayed enhancement on cardiac magnetic resonance imaging were significantly associated with the composite endpoint. On multivariable analysis, initial MMVT (HR: 5.17; 95% CI: 1.81-14.6; P = 0.001) and predischarge LV dysfunction (HR: 4.57; 95% CI: 1.83-11.5; P = 0.005) were independently associated with the composite endpoint. Using these 2 predictors, we could delineate subgroups with low (∼4%), medium (∼42%), and high (∼82%) 10-year incidence of composite endpoint. CONCLUSIONS: AM patients presenting with VA have high incidence of sustained VA recurrence and mortality posthospitalization. Initial MMVT and predischarge LV dysfunction are independently associated with VA recurrence and mortality. Implantable cardioverter-defibrillator implantation may be considered in such high-risk patients.

Patient Characteristics Associated With Using Transcatheter Left Atrial Appendage Occlusion Versus Oral Anticoagulants for Atrial Fibrillation.

BACKGROUND: Transcatheter left atrial appendage occlusion (LAAO) is an alternative to oral anticoagulants (OACs) for stroke prevention in patients with atrial fibrillation, but the predictors of LAAO use in routine care are unclear. We aimed to assess the utilization trends of LAAO and compare the change in characteristics of LAAO users versus OACs since its marketing. METHODS: Using the US Medicare claims database (March 15, 2015, to December 31, 2020), we identified patients with atrial fibrillation, ≥65 years, and CHA2DS2-VASc score ≥2 (men) or ≥3 (women), with either first implantation of an LAAO device or initiation of OACs, including apixaban, dabigatran, rivaroxaban, edoxaban, or warfarin. Patient characteristics, measured 365 days before the first LAAO or OAC use date, were compared using logistic regression. RESULTS: There were 30 058 LAAO recipients (mean age, 77.74 years; female, 42.1%) and 792 600 OAC initiators (mean age, 78.48; female, 53.3%). In 2020, patients had higher odds of initiating LAAO use than in 2015 (0.52 versus 9.32%; adjusted odds ratio [aOR], 13.64 [95% CI, 12.56-14.81]). Old age (ie, >85 versus 65-75 years; aOR, 0.84 [95% CI, 0.80-0.88]), female sex (aOR, 0.74 [95% CI, 0.71-0.76]), Black race (aOR, 0.63 [95% CI, 0.58-0.68]) versus White race, and Medicaid eligibility (aOR, 0.61 [95% CI, 0.58-0.64]) were associated with lower odds of receiving LAAO. Among clinical characteristics, frailty, cancer, fractures, and venous thromboembolism were associated with lower odds of LAAO use, while history of intracranial and extracranial bleeding, coagulopathy, and falls were associated with higher odds of receiving LAAO. CONCLUSIONS: Among patients with atrial fibrillation receiving stroke-preventive therapy, LAAO use increased rapidly from 2015 to 2020 and was positively associated with the risk factors for OAC complications but negatively associated with old age, advanced frailty, and cancer. Black race and female sex were associated with a lower likelihood of receiving LAAO.

Multicenter experience with andexanet alfa for refractory pericardial bleeding during catheter ablation of atrial fibrillation.

INTRODUCTION: Pericardial bleeding is a rare but life-threatening complication of atrial fibrillation (AF) ablation. Patients taking uninterrupted oral anticoagulation (AC) may be at increased risk for refractory bleeding despite pericardiocentesis and administration of protamine. In such cases, andexanet alfa can be given to reverse rivaroxaban or apixaban. In this study, we aim to describe the rate of acute hemostasis and thromboembolic complications with andexanet for refractory pericardial bleeding during AF ablation. METHODS AND RESULTS: In this multicenter, case series, participating centers identified patients who received a dose of apixaban or rivaroxaban within 24 h of AF ablation, developed refractory pericardial bleeding during the procedure despite pericardiocentesis and administration of protamine and received andexanet. Eleven patients met inclusion criteria, with mean age of 73.5 ± 5.3 years and median CHA2 DS2 -VASc score 4 [3-5]. All patients received protamine and pericardiocentesis, and 9 (82%) received blood products. All patients received a bolus of andexanet followed, in all but one, by a 2-h infusion. Acute hemostasis was achieved in eight patients (73%) while three required emergent surgery. One patient (9%) experienced acute ST-elevation myocardial infarction after receiving andexanet. Therapeutic AC was restarted after a mean of 2.2 ± 1.9 days and oral AC was restarted after a mean of 2.9 ± 1.6 days, with no recurrent bleeding. CONCLUSION: In patients on uninterrupted apixaban or rivaroxaban, who develop refractory pericardial bleeding during AF ablation, andexanet can achieve hemostasis thereby avoiding the need for emergent surgery. However, there is a risk of thromboembolism following administration.

Longitudinal Outcomes of Subcutaneous or Transvenous Implantable Cardioverter-Defibrillators in Older Patients.

BACKGROUND: The subcutaneous (S-) implantable cardioverter-defibrillator (ICD) is an alternative to the transvenous (TV-) ICD that is increasingly implanted in younger patients; data on the safety and effectiveness of the S-ICD in older patients are lacking. OBJECTIVES: The purpose of this study was to compare outcomes among older patients who received an S- or TV-ICD. METHODS: The authors compared S-ICD and single-chamber TV-ICD implants in Fee-For-Service Medicare beneficiaries using the National Cardiovascular Data Registry ICD Registry. Outcomes were ascertained from Medicare claims data. Cox regression or competing-risk models (with TV-ICD as reference) with overlap weights were used to compare death and nonfatal outcomes (device reoperation, device removal for infection, device reoperation without infection, and cardiovascular admission), respectively. Recurrent all-cause readmissions were compared using Anderson-Gill models. RESULTS: A total of 16,063 patients were studied (age 72.6 ± 5.9 years, 28.4% women, ejection fraction 28.3 ± 8.9%). Compared with TV-ICD patients (n = 15,072), S-ICD patients (n = 991, 6.2% overall) were more often Black, younger, and dialysis dependent and less likely to have history of atrial fibrillation or flutter. In adjusted analyses, there were no differences between device type and risk of all-cause mortality (HR: 1.020; 95% CI: 0.819-1.270), device reoperation (subdistribution [s] HR: 0.976; 95% CI: 0.645-1.479), device removal for infection (sHR: 0.614; 95% CI: 0.138-2.736), device reoperation without infection (sHR: 0.975; 95% CI: 0.632-1.506), cardiovascular readmission (sHR: 1.087; 95% CI: 0.912-1.295), or recurrent all-cause readmission (HR: 1.072; 95% CI: 0.990-1.161). CONCLUSIONS: In a large representative national cohort of older patients undergoing ICD implantation, risk of death, device reoperation, device removal for infection, device reoperation without infection, and cardiovascular and all-cause readmission were similar among S- and TV-ICD recipients.

Outcome of high-power short-duration radiofrequency ablation in combination with half-normal saline irrigation for the treatment of atrial fibrillation.

BACKGROUND: Data regarding the use of high-power short-duration (HPSD) radiofrequency (RF) in combination with half-normal saline irrigation for catheter irrigation are limited. OBJECTIVES: This study investigated the safety and efficacy of using HPSD RF ablation in combination with half-normal saline irrigation for the treatment of AF. METHODS: One hundred consecutive patients with AF underwent RF ablation using HPSD combined with half-normal saline for catheter irrigation. In addition, the following ablation strategies were used: 1 mm tags for the display of ablation lesions on the mapping system, high-frequency jet ventilation (HFJV), low contact force, pacing after ablation to verify areas of noncapture, atrial/ventricular pacing at 500 to 700 ms to aid in catheter stability, use of two skin electrodes to reduce impedance, and postablation adenosine infusion. Power was started at 40 to 45 W and was modulated manually based on impedance changes. RESULTS: The average age of patients was 65.2 years and 70% were male. Forty seven percent had paroxysmal AF and the average CHA2 DS2 -VASc score was 2.1 ± 1.6. The average power and lesion duration were 38.1 ± 3.3 W and 8.1 ± 2.3 s, respectively. During a median follow-up period of 321 ± 139 days, 89% of the patients remained free from any atrial arrhythmias after a single RF ablation procedure. No procedure-related death, stroke, pericardial effusion, or atrioesophageal fistula occurred during follow-up. CONCLUSIONS: Catheter ablation using HPSD RF lesions in combination with half-normal saline irrigation and is safe and effective, and results in high rate of freedom from AF.

The relationship between the body mass index and in-hospital mortality in patients admitted for sudden cardiac death in the United States.

While obesity has been shown to be associated with elevated risk for Sudden Cardiac Death (SCD), studies examining its effect on outcomes in SCD victims have shown conflicting results. We aimed to describe the body mass index (BMI) distribution in a nationwide cohort of patients admitted for an out of hospital SCD (OHSCD), and the relationship between BMI and in-hospital mortality. We drew data from the U.S. National Inpatient Sample (NIS), to identify cases of OHSCD. Patients were divided into six groups based on their BMI (underweight, normal weight, overweight, obese I, obese II, extremely obese). Socio-demographic and clinical data were collected, mortality and length of stay were analyzed. Multivariate analysis was performed to identify predictors of mortality. Among a weighted total of 2330 hospitalizations for OHSCD in patients with documented BMI, the mean age was 62.3 ± 29 years, 52.4% were male and 62% were white. The overall rate of in-hospital mortality was 69.3%. A U-shaped relationship between the BMI and mortality was documented, as patients with 25 < BMI < 40 exhibited significantly lower mortality (60.7%) compared to the other BMI groups (75.2%), p < .001. BMI of 25 kg/m2 and below or 40 kg/m2 and above, were independent predictors of in-hospital mortality in a multivariate analysis along with prior history of congestive heart failure and Deyo Comorbidity Index of ≥2. A U-shaped relationship between the BMI and in-hospital mortality was documented in patients hospitalized for an out of hospital sudden cardiac death in the United States in the recent years.

Ventricular arrhythmia ablation in the presence of mechanical valve utilization and complications of catheter ablation for ventricular arrhythmia in patients with mechanical prosthetic valves.

BACKGROUND: Catheter ablation (CA) for ventricular arrhythmias (VAs) is increasingly utilized in recent years. We aimed to investigate the nationwide trends in utilization and procedural complications of CA for VAs in patients with mechanical valve (MV) prosthesis. METHODS: We drew data from the US National Inpatient Sample database to identify cases of VA ablations, including premature ventricular contraction and ventricular tachycardia, in patients with MVs, between 2003 and 2015. Sociodemographic and clinical data were collected and the incidence of catheter ablation complications, mortality, and length of stay were analyzed. We compared the outcomes to a propensity-matched cohort of patients without prior valve surgery. RESULTS: The study population included a weighted total of 647 CA cases in patients with prior MVs. The annual number of ablations almost doubled, from 34 ablations on average during the "early years" (2003-2008) to 64 on average during the "late years" (2009-2015) of the study (p = .001). Length of stay at the hospital did not differ significantly between patients with MVs and 649 matched patients without prior MVs (5.4 ± 0.4, 4.7 ± 0.3 days, respectively, p = .12). The data revealed a trend toward a higher incidence of complications (12.6% vs. 7.5% respectively, p = .14) and mortality (3.7% vs. 0.7%, respectively, p = .087) among patients with MVs compared to the matched control group, not reaching statistical significance. CONCLUSION: The data show increased utilization of VA ablations in patients with MVs and a trend toward a higher incidence of in-hospital mortality and complications compared to the propensity-matched control group without MVs.

Catheter Ablation for Brugada Syndrome.

We report a case of catheter ablation of Brugada syndrome in a patient with refractory ventricular fibrillation despite quinidine therapy. We performed epicardial substrate mapping, which identified an area of abnormal fractionated, prolonged electrogram in the anterior right ventricular outflow tract. Warm saline infusion into the pericardial space induced further delay of the local electrogram, consistent with Brugada syndrome physiology. Coronary angiography confirmed that the area was distant from major coronary arteries. Ablation was performed in this area, which eliminated local abnormal electrograms and led to the disappearance of coved-type ST elevation in V1-V2. No ventricular fibrillation had recurred by five months of follow-up.

Optimizing Durability in Radiofrequency Ablation of Atrial Fibrillation.

Radiofrequency ablation (RFA) remains a highly effective therapy in the management of paroxysmal atrial fibrillation (PAF) and is an important therapeutic option in the management of persistent atrial fibrillation (PeAF) when clinically indicated. Lesion size is influenced by many parameters, which include those related to energy application (RFA power, temperature, and time), delivery mechanism (electrode size, orientation, and contact force), and the environment (blood flow and local tissue contact, stability, and local impedance). Successful durable RFA is dependent on achieving lesions that are reliably transmural and contiguous, whilst also avoiding injury to the surrounding structures. This review focuses on the variables that can be adjusted in connection with RFA to achieve long-lasting lesions that enable patients to derive the maximum sustained benefit from pulmonary vein isolation and additional lesion sets if utilized.

The Care of Patients With Atrial Fibrillation and Heart Failure.

Atrial fibrillation (AF) and heart failure (HF) are the 2 emerging epidemics in global cardiovascular disease. AF remains the most common cardiac arrhythmia, affecting over 33 million adults worldwide, and continues to increase in prevalence as the populations of many nations age. The prevalence of HF also surges, now afflicting 37 million adults globally. Interestingly, these 2 disease processes share many of the same risk factors and stem from many of the same pathophysiologic derangements, with AF occurring in over half of all patients with HF and HF occurring in over one third of all patients with AF. Furthermore, exacerbation of one of these ailments often drives decompensation or compromises therapy of the other, and it has been widely reported that coexistence of AF in patients with HF portends a poorer prognosis. As a result, many clinicians now routinely face the problem of AF in the patient with HF. In this review, we highlight the fundamental pathologic forces embedded in the relationship between AF and HF and then proceed to a discussion on the management of these complex patients with a detailed exploration of the clinical data.

A Blueprint for Productive Maintenance of Certification, But Is the American Board of Internal Medicine up to the Challenge?

The future of the American Board of Internal Medicine Maintenance of Certification (MOC) program is at a crossroads. The current MOC program lacks a clear visible mission, adds to modern health care's onerous bureaucracy, and thus pulls physicians from the most important humanistic aspects of their profession. The aim of the MOC program should be to promote the best patient care by ensuring certified physicians maintain core skills through continuous education and evaluation. The program should focus on education and be designed with the rigorous obligations of practicing physicians in mind. Moving forward, the American Board of Internal Medicine should cocreate MOC with the physician community and apply innovative adult education techniques. Over time, data-driven methods and member feedback should be used to provide continuous program improvement. This review describes the origins of the current state of MOC, explores its evidence base, provides examples of model programs for the maintenance of complex professional skills, and outlines guiding principles for the future of MOC.

Stress-Induced Cardiomyopathy Secondary to COVID-19.

A 67-year-old female with prior medical history of HTN and asthma presented with acute-onset dyspnea and nausea for 4 days prior to admission. Upon initial encounter in the emergency room, she was found to have findings of abnormal pulmonary infiltrates and consequent workup revealed COVID-19. During further hospital course, the patient developed abnormal EKG and echocardiographic findings consistent with stress-induced cardiomyopathy.

Left Atrial Appendage Anatomy: Implications for Endocardial Catheter-based Device Closure.

This clinical review focuses on both current devices approved by the United States Food and Drug Administration and investigational devices available for left atrial appendage (LAA) closure. Specifically, the article describes the anatomical considerations that are particularly relevant from a procedural standpoint. In addition, we have also focused on the technical aspects of the procedure.