One-year outcomes of pulmonary vein isolation with a novel cryoballoon: Primary results of the FROZEN AF trial.

INTRODUCTION: Cryoablation therapy for pulmonary vein isolation (PVI) to treat paroxysmal atrial fibrillation (PAF) is well established. A novel 28 mm cryoballoon system designed to operate under low pressure to safely reach a lower nadir temperature and maintain constant balloon size during cooling has not been prospectively studied in a large patient population for safety and efficacy. The FROZEN AF (NCT04133168) trial was an international multicenter, open-label, prospective, single-arm study on the safety and performance of a novel cryoballoon system for treatment of PAF. METHODS AND RESULTS: The study enrolled patients at 44 sites in 10 countries across North America, Europe, and Asia. Subjects were indicated for PVI treatment of PAF and had failed or were intolerant of one or more antiarrhythmic drugs. Procedural outcomes were defined based on the 2017 HRS consensus statement. Follow-up was performed at 7 days, 3, 6, and 12 months. Data are reported as mean ± SD or median (IQR). PVI was performed with a 28 mm cryoballoon in 325 drug refractory PAF patients. Complete PVI was achieved in 95.7% of patients. In cryoablation lesions longer than 60 s, 60.1% of PV isolations required only a single cryoballoon application. Procedure related complications included: phrenic nerve palsy [temporary 4 (1.2%), persistent 0 (0.0%)], cardiac tamponade/perforation 2 (0.6%), and air embolism 1 (0.3%). Freedom from documented atrial arrhythmia recurrence at 12 months was 79.9% (AF 82.7%, AFL 96.5%, AT 98.1%), antiarrhythmic drugs (AAD) were continued or re-initiated in 26.8% of patients after the 3-month blanking period. Additionally, an extension arm enrolled 50 pts for treatment with 28/31 mm variable size cryoballoon. A single temporary PNP occurred in this group, which resolved before discharge. Freedom from documented recurrence at 12 months in these pts was 82.0%. CONCLUSIONS: This novel cryoballoon may facilitate PVI to treat PAF, providing more options to address the variety of anatomies present in patients with PAF. This cryoballoon system proved to be safe and effective for treatment of patients with drug refractory or drug intolerant PAF.

Cardiac resynchronisation therapy in anthracycline-induced cardiomyopathy.

INTRODUCTION: Chemotherapy-induced cardiomyopathy has been increasingly recognised as patients are living longer with more effective treatments for their malignancies. Anthracyclines are known to cause left ventricular (LV) dysfunction. While heart failure medications are frequently used, some patients may need consideration for device-based therapies such as cardiac resynchronisation therapy (CRT). However, the role of CRT in anthracycline-induced cardiomyopathy (AIC) is not well understood. METHODS: We performed a retrospective review of all patients undergoing CRT implantation at our centre from 2003 to 2019 with a diagnosis of AIC. The LV remodelling and survival outcomes of this population were obtained and then compared with consecutive patients with other aetiologies of non-ischaemic cardiomyopathy (NICM). RESULTS: A total of 34 patients underwent CRT implantation with a diagnosis of AIC with a mean age of 60.5±12.7 years, left ventricular ejection fraction (LVEF) of 21.7%±7.4%, and 11.3±7.5 years and 10.2±7.4 years from cancer diagnosis and last anthracycline exposure, respectively. At 9.6±8.1 months after CRT implantation, there was an increase of LVEF from 21.8%±7.6% to 30.4%±13.0% (p<0.001). Patients whose LVEF increased by at least 10% post-CRT implant (42.5% of cohort) survived significantly longer than patients who failed to improve their LVEF by that amount (p=0.01). A propensity matched analysis between patients with AIC and 369 consecutive patients with other aetiologies of NICM who underwent CRT implantation during the same period revealed no significant differences in improvement in LVEF or long-term survival. CONCLUSIONS: Patients with AIC undergo LV remodelling with CRT at rates similar to other aetiologies of NICM. Furthermore, AIC post-CRT responders have a favourable long-term mortality compared with non-responders.

Acute safety, efficacy, and advantages of a novel cryoballoon ablation system for pulmonary vein isolation in patients with paroxysmal atrial fibrillation: initial clinical experience.

AIMS: Cryoballoon pulmonary vein isolation (PVI) is a safe and effective treatment for atrial fibrillation (AF). Current limitations include incomplete vein occlusion due to balloon rigidity and inconsistent electrogram recording, which impairs identification of isolation. We aimed to evaluate the acute safety and performance of a novel cryoballoon system. METHODS AND RESULTS: The system includes a steerable sheath, mapping catheter, and a balloon that maintains uniform inflation pressure and size following initiation of ablation. Protocol-directed cryoablation was delivered for 180 s for isolation documented in ≤60 s, otherwise freeze duration was 240 s. Primary endpoints were acute safety and vein isolation. Pulmonary vein isolation was confirmed at ≥30 min post-isolation. Data were compared across vein locations. Thirty patients with paroxysmal AF were enrolled at two centres and underwent PVI. Pulmonary vein isolation was achieved with cryoablation only in 100% of veins (120/120). Nadir temperature was -53.1 ± 5.3°C. The number of applications to achieve PVI was 1.4 ± 0.4 per vein. Of the 120 veins, 89 were isolated with a single cryothermal application (10/30 patients required only 4 total cryoablations). There were no procedural- or device-related serious adverse events at 30 days post-procedure. A subset (24/30) of patients was followed for 1-year and 71% (17/24) remained free of atrial arrhythmias. Six patients with arrhythmia recurrence were remapped and three had durable PVI for all four veins. CONCLUSION: In this first human experience, the novel cryoballoon platform was safe, efficacious, and demonstrated a high proportion of successful single ablation isolation.

Remote Hemodynamic-Guided Therapy of Patients With Recurrent Heart Failure Following Cardiac Resynchronization Therapy.

Background Patients with recurring heart failure (HF) following cardiac resynchronization therapy fare poorly. Their management is undecided. We tested remote hemodynamic-guided pharmacotherapy. Methods and Results We evaluated cardiac resynchronization therapy subjects included in the CHAMPION (CardioMEMS Heart Sensor Allows Monitoring of Pressure to Improve Outcomes in New York Heart Association Class III Heart Failure Patients) trial, which randomized patients with persistent New York Heart Association Class III symptoms and ≥1 HF hospitalization in the previous 12 months to remotely managed pulmonary artery (PA) pressure-guided management (treatment) or usual HF care (control). Diuretics and/or vasodilators were adjusted conventionally in control and included remote PA pressure information in treatment. Annualized HF hospitalization rates, changes in PA pressures over time (analyzed by area under the curve), changes in medications, and quality of life (Minnesota Living with Heart Failure Questionnaire scores) were assessed. Patients who had cardiac resynchronization therapy (n=190, median implant duration 755 days) at enrollment had poor hemodynamic function (cardiac index 2.00±0.59 L/min per m2), high comorbidity burden (67% had secondary pulmonary hypertension, 61% had estimated glomerular filtration rate <60 mL/min per 1.73 m2), and poor Minnesota Living with Heart Failure Questionnaire scores (57±24). During 18 months randomized follow-up, HF hospitalizations were 30% lower in treatment (n=91, 62 events, 0.46 events/patient-year) versus control patients (n=99, 93 events, 0.68 events/patient-year) (hazard ratio, 0.70; 95% CI, 0.51-0.96; P=0.028). Treatment patients had more medication up-/down-titrations (847 versus 346 in control, P<0.001), mean PA pressure reduction (area under the curve -413.2±123.5 versus 60.1±88.0 in control, P=0.002), and quality of life improvement (Minnesota Living with Heart Failure Questionnaire decreased -13.5±23 versus -4.9±24.8 in control, P=0.006). Conclusions Remote hemodynamic-guided adjustment of medical therapies decreased PA pressures and the burden of HF symptoms and hospitalizations in patients with recurring Class III HF and hospitalizations, beyond the effect of cardiac resynchronization therapy. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT00531661.

Comparative Analysis of Procedural Outcomes and Complications Between De Novo and Upgraded Cardiac Resynchronization Therapy.

OBJECTIVES: This study compared rates of procedural success and complications between de novo cardiac resynchronization therapy (CRT) implantation versus upgrade, including characterization of technical challenges. BACKGROUND: CRT upgrade is common, but data are limited on the incidence of procedural success and complications as compared to de novo implantation. METHODS: All patients who underwent a transvenous CRT procedure at a single institution between 2013 and 2018 were reviewed for procedure outcome, 90-day complications, reasons for unsuccessful left ventricular lead delivery, and the presence of venous occlusive disease (VOD) that required a modified implantation technique. RESULTS: Among 1,496 patients, 947 (63%) underwent de novo implantation and 549 (37%) underwent device upgrade. Patients who received a device upgrade were older (70 ± 12 years vs. 68 ± 13 years; p < 0.01), with a male predominance (75% vs. 66%; p < 0.01) and greater prevalence of comorbidities. There was no difference in the rate of procedural success between de novo and upgrade CRT procedures (97% vs. 96%; p = 0.28) or 90-day complications (5.1% vs. 4.6%; p = 0.70). VOD was present in 23% of patients who received a device upgrade and was more common among patients with a dual-chamber versus a single-chamber device (26% vs. 9%; p < 0.001). Patients with and without VOD had a similar composite outcome of procedural failure or complication (8.0% vs. 7.8%; p = 1.0). CONCLUSIONS: Rates of procedural success and complications were no different between de novo CRT implantations and upgrades. VOD frequently increased procedural complexity in upgrades, but alternative management strategies resulted in similar outcomes. Routine venography before CRT upgrade may aid in procedural planning and execution of these strategies.

Ablation of Atrial Fibrillation Without Left Atrial Appendage Imaging in Patients Treated With Direct Oral Anticoagulants.

BACKGROUND: Many centers continue to routinely perform transesophageal echocardiograms before atrial fibrillation (AF) ablation procedures in patients treated with direct oral anticoagulants (DOACs). One study suggested that the procedures could be done without transesophageal echocardiogram but used intracardiac echocardiography imaging of the appendage from the right ventricular outflow. This study aimed to assess the safety of ablation for AF without transesophageal echocardiogram screening or intracardiac echocardiography imaging of the appendage in DOAC compliant patients. METHODS: All patients undergoing AF ablation at the Cleveland Clinic (2011-2018) were enrolled in a prospectively maintained data registry. All consecutive patients presenting with AF or atrial flutter on DOAC were included. Periprocedural thromboembolic complications were assessed. RESULTS: A total of 900 patients were included. Their median CHA2DS2-VASc score was 2 (interquartile range 1-3). All were on DOACs (333 rivaroxaban, 285 dabigatran, 281 apixaban, and 1 edoxaban). Thromboembolic complications occurred in 4 patients (0.3%): 2 ischemic strokes, 1 transient ischemic attack without residual deficit, and 1 splenic infarct; all with no further complications. Bleeding complications occurred in 5 patients (0.4%): 2 pericardial effusions (1 intraoperative, 1 after 30 days, both drained), 3 groin hematomas (1 of them due to needing heparin for venous thrombosis, none required interventions). No patients required emergent surgeries. CONCLUSIONS: In DOAC compliant patients who present for ablation in AF/atrial flutter, the procedures could be performed without transesophageal echocardiogram screening or intracardiac echocardiography imaging of the appendage; with low risk of complications.

Remote Management of Pacemaker Patients With Biennial In-Clinic Evaluation: Continuous Home Monitoring in the Japanese At-Home Study: A Randomized Clinical Trial.

BACKGROUND: Current expert consensus recommends remote monitoring for cardiac implantable electronic devices, with at least annual in-office follow-up. We studied safety and resource consumption of exclusive remote follow-up (RFU) in pacemaker patients for 2 years. METHODS: In Japan, consecutive pacemaker patients committed to remote monitoring were randomized to either RFU or conventional in-office follow-up (conventional follow-up) at twice yearly intervals. RFU patients were only seen if indicated by remote monitoring. All returned to hospital after 2 years. The primary end point was a composite of death, stroke, or cardiovascular events requiring surgery, and the primary hypothesis was noninferiority with 5% margin. RESULTS: Of 1274 randomized patients (50.4% female, age 77±10 years), 558 (RFU) and 550 (Conventional follow-up) patients reached either the primary end point or 24 months follow-up. The primary end point occurred in 10.9% and 11.8%, respectively (P=0.0012 for noninferiority). The median (interquartile range) number of in-office follow-ups was 0.50 (0.50-0.63) in RFU and 2.01 (1.93-2.05) in conventional follow-up per patient-year (P<0.001). Insurance claims for follow-ups and directly related diagnostic procedures were 18 800 Yen (16 500-20 700 Yen) in RFU and 21 400 Yen (16 700-25 900 Yen) in conventional follow-up (P<0.001). Only 1.4% of remote follow-ups triggered an unscheduled in-office follow-up, and only 1.5% of scheduled in-office follow-ups were considered actionable. CONCLUSIONS: Replacing periodic in-office follow-ups with remote follow-ups for 2 years in pacemaker patients committed to remote monitoring does not increase the occurrence of major cardiovascular events and reduces resource consumption. Registration: URL: https://clinicaltrials.gov; Unique identifier: NCT01523704.

Incidence and predictors of late atrioventricular conduction recovery among patients requiring permanent pacemaker for complete heart block after cardiac surgery.

BACKGROUND: New-onset complete heart block (CHB) commonly complicates cardiac surgery, for which some patients require a permanent pacemaker (PPM). Little is known regarding late atrioventricular (AV) conduction recovery. OBJECTIVE: The purpose of this study was to characterize the incidence and predictors of late AV conduction recovery among patients requiring PPM after cardiac surgery. METHODS: Consecutive patients receiving PPM for CHB after cardiac surgery at a high-volume U.S. center from 2000 to 2014 were evaluated. The primary outcome was late AV conduction recovery, defined as a reduction in ventricular pacing requirement to <10% beyond 1 month postimplant. Regression analysis was performed to evaluate predictors of AV recovery. RESULTS: Among 301 patients evaluated over 4 ± 4 years of follow-up, the incidence of late AV conduction recovery was 12% (n = 37), for whom the median ventricular pacing requirement decreased from 96% at implant to <1% at 6 months and persisted throughout study follow-up. AV recovery was less common when preoperative conduction abnormalities were present, including no recovery among patients with preoperative PR >200 ms and QRS >120 ms (n = 42). Multivariable analysis identified only female sex and transient AV conduction postoperatively as independent predictors of recovery (odds ratio 3.5; P <.01 for each). Neither cardiac surgery subtype nor PPM implant timing postoperatively was significantly associated with recovery. CONCLUSION: Late AV conduction recovery is not uncommon after cardiac surgery, occurring in 1 of 8 patients within 6 months postoperatively. Preoperative AV conduction abnormalities were associated with decreased recovery, whereas female sex and transient postoperative AV conduction were associated with increased recovery.

Safety of Catheter Ablation for Atrial Fibrillation in Patients With Prior Cerebrovascular Events.

OBJECTIVES: This study sought to report on the safety of catheter ablation for atrial fibrillation (AF) in patients with prior cerebrovascular events (CVEs), at a large-volume tertiary care center over the course of the past 15 years. BACKGROUND: Many patients with drug-refractory AF have a history of a prior CVE. These patients are considered to be at high procedural risk for catheter ablation but data are scant. METHODS: All consecutive patients undergoing AF ablation at the Cleveland Clinic were enrolled in a prospectively maintained data registry, which was used to identify patients with a prior CVE. Strict periprocedural anticoagulation protocols were in place. Extreme care was taken with sheath and catheter manipulation to prevent thrombus formation or air embolism. All thromboembolic and hemorrhagic events occurring periprocedurally and up to 3 months of follow-up were identified. RESULTS: Of 9,413 consecutive patients who underwent AF ablation, 247 patients with a prior CVE were identified (median age, 64 years; 40.1% female; median CHA2DS2-VASC score, 4). Anticoagulants used were warfarin (n = 192), dabigatran (n = 32), rivaroxaban (n = 15), and apixaban (n = 8). All patients received intravenous heparin before transseptal access (activated clotting time target during procedure, 350 to 400 seconds). The energy source was radiofrequency in 242 patients and cryoenergy in 5 patients. Acute procedural complications included 5 groin hematomas (1 requiring transfusion), 5 pericardial effusions with associated tamponade physiology in 2 (1 required pericardiocenthesis, 1 required surgery), and 1 arteriovenous fistula (managed conservatively). Importantly, none of the patients had a periprocedural thromboembolic event. CONCLUSIONS: Patients with a prior history of cerebrovascular events do not seem to be predisposed to a significant risk of clinical CVE recurrence when undergoing catheter ablation for AF without interruption of therapeutic anticoagulation.

Infected cardiac-implantable electronic devices: prevention, diagnosis, and treatment.

Cardiac implantable electronic device (CIED) infection, according to current trends, appears to be an increasing problem. It can be indolent and its diagnosis challenging. Cardiac implantable electronic device infections are potentially lethal, and timely diagnosis and early initiation of correct treatment are of highest importance for patient prognosis. For reducing CIED infections, careful patient selection, preventative measures, and appropriate choice of device are key. The current review presents available data and consensus opinion within the field of CIED infection and identifies important current practice points and aspects for future development. Strategies for reducing CIED infection should be tested in sufficiently powered and well-designed multicentre randomized controlled trials.

Device features for managing patients with heart failure.

Implanted devices in heart failure patients improve survival, but requires correct prescription, programming, and monitoring. Requirements change since heart failure is a dynamic condition. Repeated episodes of acute decompensation increase mortality. Events involve several processes converging to manifest with fluid congestion. Implantable devices identify changes such as those in rhythm, device function or hemodynamics. Incorporation of remote monitoring technology (TRUST Trial), enables tracking of these parameters and prompt notification of deviations, even if the patient remains asymptomatic. This may facilitate management of large patient volumes and enable pre-emptive treatment to improve outcomes in these high-risk patients.

Surface electrocardiographic patterns and electrophysiologic characteristics of atrial flutter following modified radiofrequency MAZE procedures.

INTRODUCTION: The radiofrequency MAZE is becoming a common adjunct to cardiac surgery in patients with atrial fibrillation. While a variety of postoperative arrhythmias have been described following the original Cox-MAZE III procedure, the electrophysiological characteristics and surgical substrate of post-radiofrequency MAZE flutter have not been correlated. We sought to determine the location, ECG patterns, and electrophysiological characteristics of post-radiofrequency MAZE atrial flutter. METHODS: Nine consecutive patients with post-radiofrequency MAZE flutter presented for catheter ablation 9 +/- 10 months after surgery. RESULTS: Only one patient (11%) had an ECG appearance consistent with typical isthmus-dependent right atrial (RA) flutter. However, on electrophysiological study, 3/9 patients (33%) had typical right counter-clockwise flutter entrained from the cavo-tricuspid isthmus, despite description of surgical isthmus ablation. Six patients (67%) had left atrial (LA) circuits. These involved the mitral annulus in 5/6 cases (83%) despite description of surgical mitral isthmus ablation in the majority (60%). LA flutters had a shorter cycle length compared with RA flutters (253 +/- 39 msec and 332 +/- 63 msec respectively, P < 0.05). After a mean of 8 +/- 4 months following ablation, 8/9 patients (89%) were in sinus rhythm. CONCLUSION: Up to one-third of post-radiofrequency MAZE circuits are typical isthmus-dependent RA flutters, despite a highly atypical surface ECG morphology. Therefore, diagnostic electrophysiological studies should commence with entrainment at the cavo-tricuspid isthmus in order to exclude typical flutter, regardless of the surface ECG appearance. Incomplete surgical lesions at the mitral and cavo-tricuspid isthmus likely predispose to the development of post-radiofrequency MAZE flutter.