Laurence Bisch

Prevalence and risk factors related to infections of cardiac resynchronization therapy devices

AIMS Device-related infections (DRI) are not well understood in patients implanted with a cardiac resynchronization therapy (CRT) device. The aims of this study were: (i) to evaluate the prevalence of CRT DRI; (ii) to establish the factors predictive of CRT DRI. METHODS AND RESULTS Between January 2001 and May 2007, CRT implantation was performed in 303 patients (247 men, 82%). The mean follow-up was 31 +/- 19 months. Population characteristics were a mean age of 70 +/- 10 years old; 56 female; aetiology includes (202 dilated and 101 ischaemic cardiomyopathy); NYHA class 3.2 +/- 0.3; LVEF (26 +/- 6%), and a QRS width of 171 +/- 31 ms. Thirteen patients developed a DRI: endocarditis in four, pocket erosion in three, pocket abscess in five, and septicaemia in one. The prevalence of DRI was 4.3%. By univariate analysis, predictive factors of DRI were: procedure time (skin to skin: median of 85 vs. 57.5 min; P = 0.03), re-intervention (54 vs. 6.5%; P < 0.0001), haematoma (31 vs. 8.6% P = 0.01), lead dislodgement (23 vs. 6.2%; P = 0.03), dialysis (23.1 vs. 1.72%; P = 0.003), and procedure type [CRT-ICD (8.6%) vs. CRT PM (1.6%) or system up-grade (1.5%); P = 0.03]. Significant correlations were found between re-intervention and lead dislodgement (r = 0.8; P < 0.001), haematoma (r = 0.2; P < 0.001). Four independent predictive factors of DRI were identified as procedure time (P = 0.002); dialysis (P = 0.0001); re-intervention (P = 0.006), and procedure type (CRT-ICD vs. other procedures; P = 0.01). CONCLUSION This study found that the prevalence of CRT DRI is close to 4.3% at 2.6 years (1.7% per year incidence). Four independent predictive factors of infections were identified including re-intervention, procedure time, dialysis, and primo CRT-ICD implantation. These parameters should be part of the risk-benefit evaluation in patients selected for CRT implantation.

Anatomical factors involved in difficult cardiac resynchronization therapy procedure: a non-invasive study using dual-source 64-multi-slice computed tomography.

AIMS In cardiac resynchronization therapy (CRT) procedure, left ventricular (LV) lead implantation is time consuming. In this clinical setting, no study has investigated the impact of right atrium anatomical parameters on both CRT implantation procedure duration and X-ray exposure. Additionally, only few studies have examined the coronary sinus (CS) using dual-source 64-multi-slice computed tomography (DS 64-MSCT), and its impact on CRT procedure parameters has not yet been investigated. The aim of this prospective study was to identify local anatomical predictive factors of difficult CRT implantation procedure using DS 64-MSCT. METHODS AND RESULTS Between January and July 2010, 50 consecutive patients underwent primo CRT implantation. The patient population had a mean age of 70 ± 10 years, and was 34% female, with New York Heart Association Class 3.2 ± 0.3 heart failure, left ventricle ejection fraction 30 ± 4%, and QRS width 157 ± 30 ms. Cardiac resynchronization therapy implantation was attempted in 50 patients, and first LV lead implantation was obtained in 49 of 50 patients (98% primary success). One implantation failed (2%) due to unsuccessful LV lead implant. Procedure parameters were as follows: LV threshold, 1.4 ± 0.8 V; LV wave amplitude, 17 ± 8 mV; LV impedance, 830 ± 240 Ω; median procedure time (skin to skin), 51 min (38 min); median fluoroscopy procedure time, 11.9 min (22 min); and median LV fluoroscopic time, 10.3 min (22 min). In 10 patients (20%), procedures were difficult requiring an implantation lasting ≥ 85 min. The only predictive factor for difficult CRT implantation was the insertion level of the CS ostium (CSO), evaluated by the distance between the CSO and the bottom floor of the right atrium (14.8 ± 4 vs. 9.5 ± 4; P= 0.01). Neither the right atrium dilation nor right ventricular dysfunction was associated with difficult CRT implantation procedures. CONCLUSIONS Today, despite improvements in the materials used, problems still remain in the CRT procedure. In this clinical setting, the only predictive factor for very long CRT procedures is the CSO-level insertion (located high). This anatomical anomaly identified by DS 64-MSCT prior to surgery is responsible for 20% of difficult CRT device implantation procedures.

Radiofrequency Catheter Selection Based on Cavotricuspid Angiography Compared with a Control Group with an Externally Cooled-Tip Catheter: A Randomized Pilot Study

Background: Radiofrequency ablation (RFA) of cavotricuspid isthmus (CTI)‐dependent atrial flutter (AFL) can be performed using either externally cooled‐tip RFA catheters or large‐tip (8 mm) catheters. However, experimental and clinical studies suggest that the efficacy of both catheters may vary with CTI anatomy and catheters orientation.

Remote-controlled magnetic pulmonary vein isolation using a new three-dimensional non-fluoroscopic navigation system: A single-centre prospective study

BACKGROUND Catheter ablation of atrial fibrillation (AF) focuses on pulmonary vein isolation (PVI), but the procedure is associated with significant X-ray exposure. Few data exist concerning the combination of remote magnetic navigation (RMN) and a new three-dimensional non-fluoroscopic navigation system (Carto(®) 3), which facilitates precise catheter navigation and limits X-ray exposure. AIMS To assess the efficacy and extent of fluoroscopic exposure associated with the combination of RMN and the Carto 3 system in patients requiring AF ablation. METHODS Between January and September 2011, catheter ablation was performed remotely using the Carto 3 system in 81 consecutive patients who underwent PVI for symptomatic drug-refractory AF. The radiofrequency generator was set to a fixed power ≤ 35W. The primary endpoint was wide-area circumferential PVI confirmed by spiral catheter recording during ablation and including additional lesion lines (left atrial roof and coronary sinus defragmentation) or complex fractionated atrial electrograms for persistent AF. Secondary endpoints included procedural data, complications and freedom from atrial tachycardia (AT)/AF. RESULTS Mean age was 60 ± 9 years; 20% were women; 73% had symptomatic paroxysmal AF; 27% had persistent AF. The CHA2DS2-VASc score was 1.2 ± 1. Median procedure time was 3.5 ± 1 hours; median total X-ray exposure time was 13 ± 7 minutes; transseptal puncture and catheter positioning took 8 ± 4 minutes, left atrium electroanatomical reconstruction 1 ± 4 minutes and catheter ablation 3.5 ± 5minutes. Recurrences were AT (n=3; 3.7%), paroxysmal AF (n=8; 9.9%) and persistent AF (n=4; 4.9%); redo ablation was performed in these 15 (19%) patients. After a median follow-up of 15 ± 6 months and a single procedure, 71% of patients were free of symptoms; 84% remained asymptomatic after two procedures. CONCLUSIONS RMN with irrigated catheters combined with the Carto 3 system can be effectively performed in patients requiring AF ablation with minimal use of fluoroscopy, but larger randomized studies are warranted.

Remote magnetic navigation and arrhythmia ablation

Radiofrequency treatment is the first-choice treatment for arrhythmias, in particular complex arrhythmias and especially atrial fibrillation, due to the greater benefit/risk ratio compared with antiarrhythmic drugs. However, complex arrhythmias such as atrial fibrillation require long procedures with additional risks such as X-ray exposure or serious complications including tamponade. Given this context, robotic magnetic navigation is a technique well suited to the treatment of complex arrhythmias, on account of its efficacy and reliability, the significant reduction in X-ray exposure for both patient and operator, and the very low risk of perforation. As ongoing developments will likely improve results and procedure times, this technology will become one of the most advanced for treating arrhythmias.

Remote-controlled magnetic pulmonary vein isolation combined with superior vena cava isolation for paroxysmal atrial fibrillation: A prospective randomized study

BACKGROUND Radiofrequency ablation (RFA) of paroxysmal atrial fibrillation (PAF) has focused on pulmonary vein isolation (PVI). However, despite initial positive results, significant recurrences have occurred, partly because of pulmonary vein (PV) reconnection or non-PV ectopic foci, including the superior vena cava (SVC). OBJECTIVES This prospective, randomized study sought to investigate the efficacy of additional SVCI combined with PVI in symptomatic PAF patients referred for ablation. METHODS From November 2011 to May 2013, RFA was performed remotely using a CARTO(®) 3 System in patients randomized to undergo PVI for symptomatic drug-refractory PAF, with (PVI+SVCI group) or without (PVI alone group) SVCI. PVI and SVCI were confirmed by spiral catheter recording during ablation. Procedural data, complications and freedom from atrial tachycardia (AT) and atrial fibrillation (AF) were assessed. RESULTS Over an 18-month period, 100 consecutive patients (56±9years; 17 women) with symptomatic PAF were included in the study (PVI+SVCI, n=51; PVI, n=49); the CHA2DS2-VASc score was 0.9±1. Median duration of procedure (±interquartile), 2.5±1hours; total X-ray exposure, 13.3±8minutes; transseptal puncture and catheter positioning, 8±5minutes; left atrium electroanatomical reconstruction, 3±2minutes; and catheter ablation, 3.7±3minutes. After a median follow-up of 15±8months, and having undergone a single procedure, 84% of patients were symptom free, while 86% remained asymptomatic after undergoing two procedures. The cumulative risks of atrial arrhythmias (AT or AF) were interpreted using Kaplan-Meier curves and compared using the log-rank test. Long-term follow-up revealed no significant difference between groups, with atrial arrhythmias occurring in six (12%) patients in the PVI+SVCI group and nine (18%) patients in the PVI alone group (P=0.6). One transient phrenic nerve palsy and one phrenic nerve injury with partial recovery occurred in the PVI+SVCI group. CONCLUSIONS SVCI combined with PVI did not reduce the risk of subsequent AF recurrence, and was responsible for two phrenic nerve injuries. Accordingly, the benefit-to-risk ratio argues against systematic SVCI.

A single-centre experience concerning the safety of Sprint Fidelis defibrillator lead extraction at the time of pulse generator replacement or in case of evidence of lead failure

BACKGROUND The reported failure rate of the Sprint Fidelis defibrillator lead (SFDL) has increased more than initially expected, with emerging evidence of accelerating fracture rates. Current consensus guidelines continue to discourage prophylactic lead extraction, citing major complication rates of 1.4-7.3%. Therefore, data relating to the risks of systematic SFDL extraction are lacking, with no methodical extraction protocol reported to date. Moreover, few statistical analyses have identified predictors of SFDL failure. OBJECTIVES The aims of this single-centre study were: to examine the safety and feasibility of systematic SFDL extraction at the time of pulse generator replacement or in case of lead failure; and to identify predictors of SFDL failure. METHODS Between January 2005 and October 2007, 218 consecutive patients underwent transvenous SFDL implantation in our centre. RESULTS During a mean follow-up of 43 ± 15 months, SFDL extraction was performed in 49 patients (22.5%) for the following reasons: inappropriate shocks (n = 21; 9.6%), systematic extraction at time of pulse generator extraction (n = 23; 10.5%), high impedance (n = 3; 1.4%), high SFDL threshold (n = 1; 0.4%) and cardiac device-related infection (n = 1; 0.4%). No severe complications occurred, although two minor complications were reported (lead dislodgments). SFDL fracture was observed in 25 patients (11.5%; 3.2%/year incidence). The only predictor associated with SFDL fracture was the number of leads (P = 0.01). CONCLUSION In our series, SFDL extraction at the time of pulse generator extraction or in case of evidence of lead failure was feasible and safe. Number of leads was identified as a new predictive factor for SFDL fracture.

Does a patent foramen ovale matter when using a remote-controlled magnetic system for pulmonary vein isolation?

BACKGROUND Pulmonary vein isolation (PVI) takes longer when using a patent foramen ovale (PFO) compared with a transseptal puncture in paroxysmal atrial fibrillation (AF) with manual catheter ablation. To our knowledge, no data exist concerning the impact of a PFO on AF ablation procedure variables when using a remote magnetic navigation (RMN) system. AIM To assess the impact of a PFO when using an RMN system in patients requiring AF ablation. METHODS Between December 2011 and December 2012, catheter ablation was performed remotely using the CARTO(®) 3 system in 167 consecutive patients who underwent PVI for symptomatic drug-refractory AF. The radiofrequency generator was set to a fixed power ≤ 35 W. The primary endpoint was wide-area circumferential PVI confirmed by spiral catheter recording during ablation for all patients and including additional lesion lines (left atrial roof) or complex fractionated atrial electrograms for persistent AF. Secondary endpoints included procedural data. RESULTS Mean age 58±10 years; 18% women; 107 (64%) patients with symptomatic paroxysmal AF; 60 (36%) with persistent AF; CHA2DS2-VASc score 1.2 ± 1. The PFO presence was evidenced in 49/167 (29.3%) patients during the procedure but in only 26/167 (16%) by transoesophageal echocardiography. Median procedure time 2.5 ± 1 hours; median total X-ray exposure time 14 ± 7 minutes; transseptal puncture and catheter positioning time 7.5 ± 5 minutes; left atrium electroanatomical reconstruction time 3 ± 2.3 minutes; catheter ablation time 3 ± 3 minutes. No procedure time or X-ray exposure differences were observed between patients with or without a PFO during magnetic navigation catheter ablation. X-ray exposure time was significantly reduced using a PFO compared with double transseptal puncture access. CONCLUSIONS A PFO does not affect magnetic navigation during AF ablation; procedure times and X-ray exposure were similar. Septal catheter probing is mandatory to limit X-ray exposure and prevent potential complications.

Single-centre experience with an 8-mm tip catheter for radiofrequency catheter ablation of outflow tract ventricular ectopic beats.

BACKGROUND Radiofrequency ablation (RFA) of outflow tract ventricular ectopic beats (OTVEBs) can be performed using a 4-mm or externally-cooled tip RFA catheter, but no data are available concerning the safety and efficacy of a large-tip (8-mm) catheter. AIMS To evaluate the feasibility of using an 8-mm tip catheter in patients with OTVEBs. METHODS In this prospective cohort study, the 8-mm tip catheter was tested in patients who were referred to our centre for RFA of symptomatic OTVEBs. RESULTS The mean age of the 16 patients recruited between September 2008 and March 2010 was 53±18 years and 56.3% were male. Mean left ventricular ejection fraction was 62±9%, mean ventricular ectopic beat width was 144±21 ms, and all patients had left bundle branch block. Fourteen patients had inferior axis QRS morphology and two had superior. The main symptoms were palpitations and pre-syncope. RFA parameters were: procedure time 94±35 min; duration of application 11±10 min; impedance 81±12 Ω; temperature 50±5 °C; and power 46±17 W. RFA succeeded in 15 over 16 patients (93.8%); and recurrence was seen in one patient after a mean follow-up time of 11±6 months. No complications were noted. CONCLUSIONS This preliminary study suggests that an 8-mm tip catheter may represent an alternative for RFA in patients with OTVEBs in whom a 4-mm tip was not successful. Larger randomized studies are therefore warranted.

218 Prevalence and Risk Factors Related to Infections of Cardiac Resynchronization Therapy Devices

Background Device related infections [DRI] are not well understood in patients implanted with a cardiac resynchronization therapy [CRT] device. Objectives The aim of this study was twofold: [1] to evaluate the prevalence of CRT DRI; [2] to analyze the predictive factors of CRT DRI. Methods and Results From January 2001 to May 2007, CRT implantation was obtained in 303 pts. The mean follow-up was 31±19 months. Population characteristics were: mean age of 70±10 years old; 56 female; aetiology [202 dilated and 101 ischemic cardiomyopathy]; NYHA class 3.2±.3; LVEF [26±6%]; QRS [171±31] ms. Thirteen patients developed a DRI: endocarditis in 4, pocket erosion in 3, pocket abscess in 5 and septicaemia in 1. The prevalence of DRI was 4.3%. By univariate analysis, predictive factors of DRI were: procedure time [skin to skin: median of 85 vs. 57.5 min; p=. 03], reintervention [54% vs. 6.5%; p Conclusions This study found that the prevalence of CRT DRI is close to 4.3% at 2.6 years [1.7% per year incidence]. Four independent predictive factors of infections were identified including reintervention, procedure time, dialysis, and primo CRT-ICD implantation. These parameters should be part of the risk-benefit evaluation in patients selected for CRTs implantation.