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Featured topics and Editors' Picks from all of ACC's JACC Journals.

Anticoagulation Associated With Improved Outcomes in Hospitalized COVID-19 Patients


Systemic anticoagulation may be associated with improved outcomes among patients hospitalized with COVID-19, according to a research letter published in the Journal of the American College of Cardiology.

Ishan Paranjpe, BS, and Valentin Fuster, MD, PhD, MACC, et al., analyzed the association between in-hospital anticoagulation administration and mortality among patients hospitalized with COVID-19. The researchers adjusted for age; sex; ethnicity; history of hypertension, heart failure, atrial fibrillation and type 2 diabetes; anticoagulation use prior to hospitalization; and admission date. In addition, duration of anticoagulation treatment was used as a covariate and intubation was treated as a time-dependent variable.

Of 2,773 hospitalized COVID-19 patients, 786 (28%) received systemic anticoagulation during their hospital stay. The median length of stay was five days, while the median time from admission to anticoagulation initiation was two days and the median anticoagulation treatment was three days. Among patients who received anticoagulation, in-hospital mortality was 22.5% with a median survival of 21 days, compared with 22.8% and a median survival of 14 days among patients who did not receive anticoagulation.


Patients who received anticoagulation were more likely to require mechanical ventilation (29.8% vs. 8.1%). In-hospital mortality among patients requiring mechanical ventilation was 29.1% with a median survival of 21 days for those receiving anticoagulation vs. 62.7% with a median survival of nine days for patients not receiving anticoagulation.

Longer duration of anticoagulation treatment was associated with a reduced mortality risk (adjusted hazard ratio, 0.86 per day; 95% confidence interval 0.82 to 0.89; p<0.001). In addition, 24 patients (3%) who received anticoagulation had bleeding events, compared with 38 patients (1.9%) among those who did not receive anticoagulation. Bleeding events were more common among patients who were intubated (7.5%) vs. nonintubated patients (1.35%).

According to the researchers, anticoagulation may be associated with improved outcomes in COVID-19 patients, but the benefits should be weighed against the risk of bleeding. The findings provide clinical insights for hospitalized COVID-19 patients, but additional research is needed to determine whether systemic anticoagulation is associated with increased survival, the researchers conclude.

It must be noted that in an observational study like this, it is very difficult to gauge treatment effects in the presence of unmeasured confounders and inherent treatment biases that may exist, commented Kim A. Eagle, MD, MACC, ACC.org Editor-in-Chief.

"Nevertheless, studies to date suggest that COVID-19 is often associated with heightened coagulation and it stands to reason that anticoagulants have an important role to reduce clinically important procoagulant clinical events including deep vein thrombosis, pulmonary embolism and stroke."

Paranjpe I, Fuster V, Lala A, et al. J Am Coll Cardiol 2020;May 6:[Epub ahead of print].


Is High-Power Short-Duration Ablation Effective Long-Term For AFib?

JACC: Clinical Electrophysiology

High-power short-duration (HP-SD) ablation may improve pulmonary vein isolation (PVI) durability and shorten radiofrequency ablation time, according to research presented as part of the 2020 Heart Rhythm Scientific Sessions and simultaneously published in JACC: Clinical Electrophysiology.

Hagai D. Yavin, MD, et al., compared the acute safety and long-term lesion durability between HP-SD (45-50 W for 8-15 sec) and moderate-power moderate-duration (MP-MD) (20-40 W, 20-30 sec) ablation for the treatment of atrial fibrillation (AFib), including PVI and linear ablation.

Results showed that of the 112 patients with symptomatic paroxysmal or persistent AFib included in this prospective single-center study, the rate of PVI at the completion of the initial encirclement was similar between HP-SD ablation and MP-MD ablation in 112 historical controls (90.2% vs. 83%; p=0.006). However, the authors found the HP-SD strategy required shorter radiofrequency time (17.2 min vs. 31.1 min; p<0.001).


Furthermore, the incidence of chronic PV reconnection was found to be lower with HP-SD ablation, and in a higher proportion of HP-SD applications, catheter motion was less than 1 mm during 50% or more of application duration, allowing energy delivery with greater stability.

The authors found that both ablation strategies were effective for cavotricuspid isthmus; however, high-power short-duration was less effective for mitral annular line, requiring ablation at lower powers for longer durations to avoid steam pops. In an accompanying editorial comment, Felix Bourier, MD, and Philipp Sommer, MD, note this study "presents data on the effect of high-power short-duration on midterm outcome, but also highlights the importance of catheter stability on lesion formation and the rate of chronic pulmonary vein isolations." They add, "More and more data seem to justify that different patients may need different treatment strategies – and this may not only be true in terms of where to deploy the lesions but also in how to deploy the lesions."

Yavin HD, Leshem E, Shapira-Daniels A, et al. JACC Clin Electrophysiol 2020;May 5:Epub ahead of print].


ACC Council Perspective Provides Current Review of AFib


While significant progress has been made in addressing atrial fibrillation (AFib), a better understanding may be needed on substrate progression, evolution of nonpulmonary vein triggers and a comprehensive approach to multisystem risk factor modification, according to a perspective from ACC's Electrophysiology Council published in the Journal of the American College of Cardiology.

Mina K. Chung, MD, FACC, et al., review the current knowledge on the prevalence, pathophysiology, risk prediction, prophylaxis and treatment options, as well as new insights for optimizing treatment outcomes and emerging concepts of AFib. They note that AFib is a cardiovascular pandemic with a complex pathophysiology and contributes to significant patient morbidity and mortality.


In reviewing strategies for primary and secondary prevention of AFib, they explain that primary prevention has focused mostly on reversing the modifiable risk factors and secondary prevention has focused on reducing the burden of AFib and preventing its progression to more persistent forms. They discuss the potential of upstream targets and agents, and using genetics to target AFib therapy.

Following the initial assessment of patients with AFib, the authors state treatment strategies need to be developed with two major goals: 1) preventing thromboembolism, and 2) symptom control with either a rhythm control or rate control strategy. Along with a review of oral anticoagulation therapy and management of bleeding, they look at the use of left atrial appendage closure as well as rate and rhythm control strategies, including ablation.

While a "unifying hypothesis" that explains all causes of AFib has not emerged, the authors state AFib appears to be a "final common pathway" resulting from the influence of varied genetic, environmental, cellular stress and lifestyle factors. "Difficulties in predicting the consequences of AFib and its therapies and the limitations of current therapies make it imperative to study and improve preventive and therapeutic strategies," the authors conclude. "A hope is that basic and translational research will lead to more effective and safe therapeutic options, including pharmacological and nonpharmacological ablative approaches."

Chung MK, Refaat M, Shen W-K, et al. J Am Coll Cardiol 2020;75:1689-1713.


Research Finds HPCSP Mostly Safe in Patients Requiring Pacing Post TAVR

JACC: Clinical Electrophysiology

His Purkinje conduction system pacing (HPCSP) may be feasible and safe in the majority of patients requiring pacemakers post TAVR, according to research presented as part of the 2020 Heart Rhythm Scientific Sessions and simultaneously published in JACC: Clinical Electrophysiology.

Pugazhendhi Vijayaraman, MD, FACC, et al., analyzed patients at five centers who had His bundle pacing (HBP) or left bundle branch area pacing (LBBAP) attempted following TAVR. They assessed implant success rates, pacing characteristics, QRS duration and left ventricular ejection fraction (LVEF).

Results showed that HPCSP was overall successful in 55 of 65 (85%) patients post TAVR patients with a mean age of 79 years. HBP was found to be successful in 29 of 46 patients (63%) while LBBAP was successful in 26 of 28 patients (93%).


Furthermore, the authors found that HBP was more successful in patients with Sapien valves compared with those with CoreValves (69% vs. 44%), and that LBBAP was associated with higher success rates and lower pacing thresholds compared with HBP.

The authors also found pacing thresholds remained stable and LVEF remained unchanged during a mean follow-up of 12 months.

In an accompanying editorial comment, Jordana Kron, MD, FACC, and Santosh K. Padala, MD, FACC, write that "one of the most elegant findings of this work is the validation of the anatomic relationship between the prosthetic aortic valve location and the bundle of His, which can be used to guide physiologic pacing implanters." They add, "While further studies assessing long-term clinical outcomes with LBBAP are required, this study is a valuable contribution to the literature and provides an impetus for long-term physiologic pacing studies in the post TAVR population."

Vijayaraman P, Cano Ó, Koruth JS, et al. JACC Clin Electrophysiol 2020;May 5:Epub ahead of print].


PRECEPT Study: Contact Force-Sensing Catheter Safe, Effective in Treatment of Persistent AFib

JACC: Clinical Electrophysiology

Catheter ablation with a contact force (CF)-sensing catheter may be safe and effective in treatment of persistent atrial fibrillation (AFib), according to results of the PRECEPT study presented as part of the 2020 Heart Rhythm Scientific Sessions and simultaneously published in JACC: Clinical Electrophysiology.

Moussa Mansour, MD, FACC, et al., evaluated the safety and effectiveness of the Thermocool Smarttouch SF (STSF) catheter for the treatment of drug-refractory symptomatic persistent AFib. The study's primary safety endpoint was incidence of primary adverse events within seven days of initial and repeat ablation procedures using the STSF catheter.

The primary effectiveness endpoint was freedom from AFib/atrial flutter or atrial tachycardiac episodes of 30 seconds or longer and freedom from five variables at 15 months post procedure: acute procedural failure, use of nonstudy catheter, repeat procedures, use of new or higher-dose antiarrhythmic drug, and surgical ablation.


The study enrolled 381 participants at 27 sites across the U.S. and Canada. All patients had symptomatic persistent AFib, as well as documented nonresponse or intolerance to one or more antiarrhythmic drug. After ablation with the STSF catheter, patients were followed up at one, three, six, nine, 12 and 15 months.

Electrocardiograms were obtained at baseline and discharge and at six, nine, 12 and 15 months, while 24-hour Holter monitoring was performed at baseline and at six, 12 and 15 months. In addition, transtelephonic monitoring transmissions were performed monthly or when symptoms occurred during the nine-month follow-up period.

Of the 381 participants, 348 had the STSF catheter inserted and underwent radiofrequency (RF) ablation, comprising the safety population. Of these patients, 13 (3.8%) experienced a primary adverse event. The effectiveness population consisted of 333 patients. Of these, 330 (99.1%) achieved acute procedure success. After 15 months, the primary effectiveness success rate was 61.7% and the clinical success rate, defined as freedom from symptomatic AFib, was 80.4%.

According to the researchers, the findings demonstrate safety and effectiveness of persistent AFib ablation with CF-sensing catheters. Individualized ablation approaches based on a patient's clinical presentation could help optimize outcomes, they conclude. The researchers note that future research is needed to determine the decrease in atrial arrhythmia following catheter ablation treatment for persistent AFib.

In an accompanying editorial comment, Edward P. Gerstenfeld, MD, MS, FACC, and Joshua D. Moss, MD, FACC, write that the findings will likely result approval of the STSF catheter from the U.S. Food and Drug Administration but the "more interesting question is whether use of modern irrigated CF-sensing catheters has improved our overall results treating" persistent AFib. They add that treatment for persistent AFib has been "possibly further enhanced with the availability" of CF-sensing catheters.

Mansour M, Calkins H, Osorio J, et al. JACC Clin Electrophysiol 2020;May 8:[Epub ahead of print].


Clinical Topics: Arrhythmias and Clinical EP, EP Basic Science, Atrial Fibrillation/Supraventricular Arrhythmias

Keywords: ACC Publications, Cardiology Magazine, Atrial Fibrillation, Atrial Flutter, COVID-19, Pandemics, Pulmonary Veins, Incidence, Risk Factors, Prevalence, Hospital Mortality, Length of Stay, Prospective Studies, Stroke Volume, Ethnic Groups, Diabetes Mellitus, Type 2, Bundle of His

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