Richard Balasubramaniam

Uninterrupted rivaroxaban vs. uninterrupted vitamin K antagonists for catheter ablation in non-valvular atrial fibrillation

Aims VENTURE-AF is the first prospective randomized trial of uninterrupted rivaroxaban and vitamin K antagonists (VKAs) in patients with non-valvular atrial fibrillation (NVAF) undergoing catheter ablation (CA). Methods and results Trial size was administratively set at 250, the protocol-specified target. Events were independently and blindly adjudicated. We randomly assigned 248 NVAF patients to uninterrupted rivaroxaban (20 mg once-daily) or to an uninterrupted VKA prior to CA and for 4 weeks afterwards. The primary endpoint was major bleeding events after CA. Secondary endpoints included thromboembolic events (composite of stroke, systemic embolism, myocardial infarction, and vascular death) and other bleeding or procedure-attributable events. Patients were 59.5 ± 10 years of age, 71% male, 74% paroxysmal AF, and had a CHA2DS2-VASc score of 1.6. The average total heparin dose used to manage activated clotting time (ACT) was slightly higher (13 871 vs. 10 964 units; P < 0.001) and the mean ACT level attained slightly lower (302 vs. 332 s; P < 0.001) in rivaroxaban and VKA arms, respectively. The incidence of major bleeding was low (0.4%; 1 major bleeding event). Similarly, thromboembolic events were low (0.8%; 1 ischemic stroke and 1 vascular death). All events occurred in the VKA arm and all after CA. The number of any adjudicated events (26 vs. 25), any bleeding events (21 vs. 18), and any other procedure-attributable events (5 vs. 5) were similar. Conclusion In patients undergoing CA for AF, the use of uninterrupted oral rivaroxaban was feasible and event rates were similar to those for uninterrupted VKA therapy. Name of the Trial Registry Clinicaltrials.gov trial registration number is NCT01729871.

No Benefit of Complex Fractionated Atrial Electrogram Ablation in Addition to Circumferential Pulmonary Vein Ablation and Linear Ablation: Benefit of Complex Ablation Study.

Background—The optimal ablation strategy for persistent atrial fibrillation (AF) remains unclear. Methods and Results—This multicentre randomized study compared circumferential pulmonary vein ablation+linear ablation (control arm) versus circumferential pulmonary vein ablation+linear ablation+complex fractionated atrial electrogram (CFAE) ablation (CFAE arm) in patients with persistent AF. Circumferential pulmonary vein ablation was performed followed by roof and mitral isthmus ablation, before CFAE ablation in the CFAE arm. Ablation strategy was maintained at the first redo procedure. Sixty-five patients were recruited in each arm. The mean age was 61±10 years, 75% were men, median AF duration was 2 years, 42% had long-lasting persistent AF, 68% had associated cardiovascular disease, mean left atrial dimension was 46±6 mm, and median CHA2DS2-VASc score was 2. Ablation and procedure times were significantly longer in the CFAE arm (70±20 versus 55±17; 201±35 versus 152±45 minutes; P<0.005). After a mean follow-up of 35±5 months, single-procedural success off antiarrhythmic drugs at 12 months (CFAE: 30/65 [46%] versus control: 37/65 [57%]; P=0.29) and multiprocedural success (CFAE: 51/65 [78%] versus control: 52/65 [80%]; P=1.0) were not significantly different. At the first redo procedure, patients in the CFAE arm had a higher incidence of organized atrial tachycardia/flutter (24/33 [73%] versus 11/31 [35%]; P=0.005) and gap-related macro–re-entrant flutter (8/33[24%] versus 1/31[3%]; P=0.03). Early recurrence of atrial arrhythmia was an independent predictor of late recurrence. Conclusions—CFAE ablation did not confer incremental benefit when performed in addition to circumferential pulmonary vein ablation and linear ablation. It was associated with a higher incidence of gap-related flutter. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT01711047.

No Benefit OF Complex Fractionated Atrial Electrogram (CFAE) Ablation in Addition to Circumferential Pulmonary Vein Ablation and Linear Ablation: BOCA Study

Background—The optimal ablation strategy for persistent atrial fibrillation (AF) remains unclear. Methods and Results—This multicentre randomized study compared circumferential pulmonary vein ablation+linear ablation (control arm) versus circumferential pulmonary vein ablation+linear ablation+complex fractionated atrial electrogram (CFAE) ablation (CFAE arm) in patients with persistent AF. Circumferential pulmonary vein ablation was performed followed by roof and mitral isthmus ablation, before CFAE ablation in the CFAE arm. Ablation strategy was maintained at the first redo procedure. Sixty-five patients were recruited in each arm. The mean age was 61±10 years, 75% were men, median AF duration was 2 years, 42% had long-lasting persistent AF, 68% had associated cardiovascular disease, mean left atrial dimension was 46±6 mm, and median CHA2DS2-VASc score was 2. Ablation and procedure times were significantly longer in the CFAE arm (70±20 versus 55±17; 201±35 versus 152±45 minutes; P<0.005). After a mean follow-up of 35±5 months, single-procedural success off antiarrhythmic drugs at 12 months (CFAE: 30/65 [46%] versus control: 37/65 [57%]; P=0.29) and multiprocedural success (CFAE: 51/65 [78%] versus control: 52/65 [80%]; P=1.0) were not significantly different. At the first redo procedure, patients in the CFAE arm had a higher incidence of organized atrial tachycardia/flutter (24/33 [73%] versus 11/31 [35%]; P=0.005) and gap-related macro–re-entrant flutter (8/33[24%] versus 1/31[3%]; P=0.03). Early recurrence of atrial arrhythmia was an independent predictor of late recurrence. Conclusions—CFAE ablation did not confer incremental benefit when performed in addition to circumferential pulmonary vein ablation and linear ablation. It was associated with a higher incidence of gap-related flutter. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT01711047.

Is cardiac resynchronisation therapy feasible, safe and beneficial in the very elderly?

Objective To evaluate whether cardiac resynchronisation therapy (CRT) implantation was feasible and safe in octogenarians and the association with symptoms. Methods Consecutive patients undergoing CRT implantation were recruited from two UK centers. Patients grouped according to age: < 80 & ≥ 80 years. Baseline demographics, complications and outcomes were compared between those groups. Results A total of 439 patients were included in this study, of whom 26% were aged ≥ 80 years. Octogenarians more often received cardiac resynchronization therapy pacemaker in comparison to cardiac resynchronisation therapy-defibrillator. Upgrade from pacemaker was common in both groups (16% < 80 years vs. 22% ≥ 80 years, P = NS). Co-morbidities were similarly common in both groups (overall diabetes: 25%, atrial fibrillation: 23%, hypertension: 45%). More patient age ≥ 80 years had significant chronic kidney disease (CKD, estimated glomerular filtration rate < 45 mL/min per 1.73 m2, 44% vs. 22%, P < 0.01). Overall complication rates (any) were similar in both groups (16% vs. 17%, P = NS). Both groups demonstrated symptomatic benefit. One-year mortality rates were almost four fold greater in octogenarians as compared with the younger cohort (13.9% vs. 3.7%, P < 0.01). Conclusions CRT appears to be safe in the very elderly despite extensive co-morbidity, and in particular frequent severe CKD. Symptomatic improvement appears to be meaningful. Strategies to increase the appropriate identification of elderly patients with CHF who are potential candidates for CRT are required.

Type 1 Brugada ECG unmasked by intracoronary contrast media

A 48-year-old man was admitted with chest discomfort. His ambulance electrocardiograph (ECG) documented ST-segment elevation in V1–V3. Immediate coronary angiography demonstrated smooth, normal, coronary arteries with no evidence of thrombus, plaque disease or coronary spasm. It was noted that injection of contrast medium (Omnipaque) resulted in further ST-segment deviation. The changes resembled those seen in a type 1 Brugada pattern. Subsequent Cardiac MRI scanning …

Extended bipolar left ventricular pacing as a possible therapy for late electrical storm induced by cardiac resynchronization therapy

Although cardiac resynchronization therapy (CRT) has become a well-established treatment option for patients with drug-refractory severe systolic heart failure, there has been some evidence of adverse proarrhythmic events. We report a case of a patient with ischemic cardiomyopathy who underwent CRT with a defibrillator for primary prevention of sudden cardiac death. Two years after the implantation, the patient presented with electrical storm, which was completely terminated by modifying the left ventricular (LV) pacing configuration from true to extended bipolar LV pacing. We discuss the possible pathophysiologic mechanisms of this phenomenon through a brief review of the literature on CRT-induced proarrhythmia.

52 Immediate Management Following Cardiac Implantable Electronic Device Procedures; Wide Variation in Practice from a UK Survey

Introduction Following the implantation of a CIED a number of checks are made to document device function and exclude procedure complications. Traditionally these have been performed the day after the procedure, mandating an overnight admission. Recently, both the need for these investigations and their timings have been questioned, especially in the context of same day discharge practices. Methods Staff at the largest volume device implant centres in the UK as well as to a selection of other implant centres chosen on an ad hoc basis were surveyed. Responses were received from 31 centres. The aim of the study was to assess the range of post implant practice currently used in the UK relating to device procedures where a new lead was introduced. Results A range of practices were described relating to the timing and use of both CXR and device checks. 35.5% of centres did not mandate a post procedure CXR. At these centres, the most common reasons for requiring a CXR were the type of access used and the suspicion of procedure complication. Use of device checks once a patient had left theatre also varied. Most centres performed a full interrogation, however 4 used only a 12 lead ECG, one a magnet check and one required no further check other than that performed on the table at the end of the case. Timings for the CXR and check were similar within a centre but differed significantly between centres. 65% of centres responded to indicate that both investigations could be performed after a wait of 4 h or less from the time of implant. Same day discharge following bradycardia device implant was considered at 68% of centres and 55% of centres following ICD/CRT device procedures. A number of factors were said to be used to guide its suitability. Routine echo optimisation of all CRT devices was only reported by 16% of centres. Conclusion There is a broad range of different practice between UK centres, relating to both the timing and use of CXR and device checks. Although still carried out in a large number of centres, traditional next day checks are no longer the norm.

Successful release of an entrapped circular mapping catheter using a snare and a multidisciplinary approach

A 44-year-old attended for pulmonary vein isolation procedure as treatment for highly symptomatic, paroxysmal atrial fibrillation. SLO sheaths (St Jude Medical, USA) were used to facilitate introduction of a 3.5-mm irrigated tip ablation catheter and a 15-mm circular mapping catheter (Lasso®, Biosense Webster, USA) into the left atrium via trans-septal access. Geometry for a non-contact mapping system was collected using the circular mapping catheter. During manipulation of the catheter, it became entangled in the mitral valve apparatus (Fig. 1). Following a number of unsuccessful manoeuvres to free the catheter including gentle clockwise or anticlockwise rotation whilst either advancing or withdrawing the catheter, performing the same motions with the sheath advanced to the fixed portion of the catheter, and trying to free the catheter using a pigtail catheter introduced retrograde via the femoral artery (Fig. 1D), we sought assistance from an Interventional Radiology colleague. Our hypothesis from fluoroscopic and echocardiographic imaging was that a pair of chordae had entwined the point of intersection of the catheter in opposite directions, thus fixing it and preventing release by rotation in either direction. The distal tip of the circular mapping catheter was captured using a snare (9–15 mm EN SnareTM Endovascular Snare System, Merit Medical, USA) delivered through a trans-septal AgilisTM steerable sheath (St. Jude Medical, USA), positioned in place of the free SLO. By combining the experience of the radiologist in utilising snare devices and the detailed cardiac anatomical knowledge and catheter manipulation skills of the electrophysiologist, we were able to fix the distal tip of the mapping catheter and provide counter traction as it was rotated, thus facilitating its safe release from the mitral valve apparatus (Fig. 2). Transthoracic echocardiography directly after catheter release and at 4 weeks post procedure demonstrated no significant mitral regurgitation. The patient has since undergone successful pulmonary vein isolation without incident. The rotational techniques of manipulation and the shape of a circular mapping catheter are such that it is now well established that it can entangle in the mitral valve apparatus and become trapped. Measures to prevent this complication include using only clockwise rotation of the catheter (Fig. 3) and deliberate manipulation of the catheter along the posterior rather than anterior aspect of the left atrium. Specific features that may contribute to the tendency include the bulbous distal tip and the inherent “shape memory” from the Nitinol composition of the catheter. The incidence of entrapment as a complication is not well understood; some publications place it as high as 0.9% [Kesek M et al. Heart Rhythm, 2007; 4: 17–91]. Reported consequences of the phenomenon include surgical extraction of the catheter [Grove R et al. Clin Res Cardiol, 2008; 97: 628–629], severe damage to the valve requiring surgical repair during percutaneous removal of the catheter, and a small number of reports of techniques used to affect safe, percutaneous release of the device. Ours is the first to document the successful use of a snare to facilitate catheter release. We believe that co-operation between the 2 interventional specialists was a major component of the safe release of the instrument.