Very long-term survival and late sudden cardiac death in cardiac resynchronization therapy patients.

AIMS: The very long-term outcome of patients who survive the first few years after receiving cardiac resynchronization therapy (CRT) has not been well described thus far. We aimed to provide long-term outcomes, especially with regard to the occurrence of sudden cardiac death (SCD), in CRT patients without (CRT-P) and with defibrillator (CRT-D). METHODS AND RESULTS: A total of 1775 patients, with ischaemic or non-ischaemic dilated cardiomyopathy, who were alive 5 years after CRT implantation, were enrolled in this multicentre European observational cohort study. Overall long-term mortality rates and specific causes of death were assessed, with a focus on late SCD. Over a mean follow-up of 30 months (interquartile range 10-42 months) beyond the first 5 years, we observed 473 deaths. The annual age-standardized mortality rates of CRT-D and CRT-P patients were 40.4 [95% confidence interval (CI) 35.3-45.5] and 97.2 (95% CI 85.5-109.9) per 1000 patient-years, respectively. The adjusted hazard ratio (HR) for all-cause mortality was 0.99 (95% CI 0.79-1.22). Twenty-nine patients in total died of late SCD (14 with CRT-P, 15 with CRT-D), corresponding to 6.1% of all causes of death in both device groups. Specific annual SCD rates were 8.5 and 5.8 per 1000 patient-years in CRT-P and CRT-D patients, respectively, with no significant difference between groups (adjusted HR 1.0, 95% CI 0.45-2.44). Death due to progressive heart failure represented the principal cause of death (42.8% in CRT-P patients and 52.6% among CRT-D recipients), whereas approximately one-third of deaths in both device groups were due to non-cardiovascular death. CONCLUSION: In this first description of very long-term outcomes among CRT recipients, progressive heart failure death still represented the most frequent cause of death in patients surviving the first 5 years after CRT implant. In contrast, SCD represents a very low proportion of late mortality irrespective of the presence of a defibrillator.

Do women benefit equally as men from the primary prevention implantable cardioverter-defibrillator?

Women traditionally have been and are still underrepresented in research in many important areas of cardiology, and guideline recommendations which also encompass women are mostly based on research conducted predominantly in men. However, there is plausible cause to believe that sex may have a potential influence on the benefit derived from the implantable cardioverter-defibrillators (ICD), alone or in association with cardiac resynchronization therapy. We assessed the possible relationship between sex and outcome with ICD implantation in the setting of primary prevention, by pooling the results of MUSTT, MADIT-II, DEFINITE, COMPANION, SCD-HeFT and DANISH trials in a meta-analysis. We pooled results for female and male patients separately. The results suggest that women as a group do not seem to obtain a significant survival benefit from the primary prevention ICD, contrary to men. This in turn may also have contributed to a relative underestimation of the ICD benefit among males when looking at the results in total. It is time for the medical and research communities to actively question the presumed overarching benefit of ICDs irrespective of sex and engage in systematic scientific efforts to definitively evaluate the value of this intervention in women.

Improved outcome and cost effectiveness in ablation of persistent atrial fibrillation under general anaesthetic.

Aims: Outcome of persistent atrial fibrillation (AF) ablation remains suboptimal. Techniques employed to reduce arrhythmia recurrence rate are more likely to be embraced if cost-effectiveness can be demonstrated. A single-centre observational study assessed whether use of general anaesthesia (GA) in persistent AF ablation improved outcome and was cost-effective. Methods and results: Two hundred and ninety two patients undergoing first ablation procedures for persistent AF under conscious sedation or GA were followed. End points were freedom from listing for repeat ablation at 18 months and freedom from recurrence of atrial arrhythmia at 1 year. Freedom from atrial arrhythmia was higher in patients who underwent ablation under GA rather than sedation (63.9% vs. 42.3%, hazard ratio (HR) 1.87, 95% confidence interval (CI): 1.23-2.86, P = 0.002). Significantly fewer GA patients were listed for repeat procedures (29.2% vs. 42.7%, HR 1.62, 95% CI: 1.01-2.60, P = 0.044). Despite GA procedures costing slightly more, a saving of £177 can be made per patient in our centre for a maximum of two procedures if all persistent AF ablations are performed under GA. Conclusions: In patients with persistent AF, it is both clinical and economically more effective to perform ablation under GA rather than sedation.

Patients upgraded to cardiac resynchronization therapy due to pacing-induced cardiomyopathy are at low risk of life-threatening ventricular arrhythmias: a long-term cause-of-death analysis.

Aims: Upgrade to cardiac resynchronization therapy (CRT) should be offered to patients who have developed pacing-induced cardiomyopathy with conventional right ventricular pacing. The extent to which these patients would also benefit from defibrillator back-up at the time of CRT upgrade is, however, unknown. Methods and results: Retrospective observational cohort study of 199 patients with pacing-induced cardiomyopathy and no history of sustained ventricular arrhythmia, including 104 upgraded to CRT-Pacemaker (CRT-P) and 95 upgraded to CRT-Defibrillator (CRT-D). The incidence of ventricular arrhythmias and the risk of sudden arrhythmic death obtained through a cause-of-death analysis based on clinical data and necropsy results were assessed and compared between the two groups. During a mean follow-up of 66 ± 24 months, 40 (38.5%) CRT-P patients died: three from primary arrhythmic death, while the remaining died of different causes (especially progressive heart failure), giving an incidence of 6.2 sudden arrhythmic deaths per 1000 patient-years. No episode of sustained VT was observed in the study group. There were no sudden arrhythmic deaths in the CRT-D group during a shorter follow-up, but the small and non-significant difference in all-cause mortality between CRT-Pacemaker (CRT-P) and CRT-D groups was mostly accounted for by an increase in non-sudden death. Women upgraded to CRT were at particularly low risk of all-cause mortality compared with men (HR 0.232, P = 0.048). Conclusion: Our findings suggest that patients who develop pacing-induced cardiomyopathy and are upgraded to CRT may not derive any significant benefit from the addition of the defibrillator in the absence of a history of ventricular arrhythmias.

Applicability of a risk score for prediction of the long-term benefit of the implantable cardioverter defibrillator in patients receiving cardiac resynchronization therapy.

AIMS: The Goldenberg risk score, comprising five clinical risk factors (New York Heart Association class >2, atrial fibrillation, QRS duration >120 ms, age >70 years, and urea >26 mg/dL), may help identify patients in whom the survival benefit of the defibrillator may be limited. We aim at assessing whether this score can accurately predict the long-term all-cause mortality risk of patients receiving cardiac resynchronization therapy (CRT) and identify those who are more likely to benefit from the defibrillator. METHODS AND RESULTS: In this retrospective observational cohort study, 638 patients with ischaemic or non-ischaemic dilated cardiomyopathy who had CRT-defibrillator (CRT-D) (n = 224) vs. CRT-pacemaker (CRT-P) (n = 414) implantation were prospectively followed up for survival outcomes. The long-term outcome of patients with CRT-D vs. CRT-P was compared within risk score categories and in patients with severe renal dysfunction. Mean follow-up in surviving and deceased patients was 62.7 and 32.5 months, respectively. This score showed higher discriminative performance in all-cause mortality prediction in CRT-D vs. CRT-P patients (area under the curve 0.718 ± 0.041 vs. 0.650 ± 0.032, respectively, P = 0.001). In those with scores 0-2, a CRT-D device decreased mortality rates in the first 4 years of follow-up compared with CRT-P (11.3 vs. 24.7%, P = 0.041), but this effect attenuated with longer follow-up duration (21.2 vs. 32.7%, P = 0.078). In this group, the benefit of CRT-D during the follow-up was seen after adjusting for traditional mortality predictors (hazard ratio 0.339, P = 0.001). No significant differences in mortality rates were seen in patients with score ≥3 (57.9% with CRT-D vs. 56.9%, P = 0.8) and those with severe renal dysfunction (92.9% in CRT-D vs. 76.2%, P = 0.17). Similar results were seen following propensity score matching. CONCLUSION: A simple risk stratification score comprising five clinical risk factors may help identify CRT patients who are more likely to benefit from the presence of the defibrillator.

Cardioverter-defibrillator implantation and generator replacement in the octogenarian.

AIMS: Increase in life expectancy has led to increased rate of implantable cardioverter-defibrillator (ICD) implantation in patients in their 80s, but there are no current formal recommendations to guide physicians when elderly patients with ICDs require elective unit replacement (EUR). This study aims at assessing survival and rates of ICD therapies in patients who have had ICD implantation or EUR above the age of 80, focusing on the latter. METHODS AND RESULTS: Retrospective analysis of a prospectively kept database of all ICD-related procedures carried out in a single tertiary centre. Patients 80 years of age or older submitted to ICD implantation (n = 42) or EUR (n = 34) between November 1991 and May 2012 were included. Using collected baseline and outcome data from this cohort, we assessed survival of these patients and the rates of ICD therapies. Median additional years of life after ICD implantation and ICD EUR in patients who died before data retrieval was 2.5 and 1.2, respectively, and while 65% of deceased patients after ICD implantation died in the first 3 years after the procedure, 50% of deceased post-ICD EUR patients died within the first year. Mortality rates at 1 and 2 years post-EUR were 23.1 and 38.1%, respectively. Furthermore, ventricular tachycardia occurred in a small minority of patients after EUR (16.7%) and no ventricular fibrillation-triggered ICD therapies were reported in both groups. CONCLUSION: In octogenarians who are due for an ICD EUR, careful thought should be given to the current clinical status, comorbidities, and general frailty prior to considering them for the procedure. A survival benefit from ICD EUR in this age stratum is not likely.

Oral amiodarone provoking inferior ST elevation and unmasking Brugada-like electrocardiogram feature.

A woman presented with broad complex tachycardia. She was converted to sinus rhythm with intravenous amiodarone and continued on oral amiodarone. The amiodarone was stopped 3 weeks later as she was pregnant. Electrocardiogram (ECG) then revealed coved-type ST elevation in C1, suggestive of Brugada syndrome, and widespread inferior ST elevation. Electrocardiogram several months later showed resolution of inferior ST elevation.

Supraventricular arrhythmias late after orthotopic cardiac transplantation: electrocardiographic and electrophysiological characterization and radiofrequency ablation.

AIMS: Cardiac transplantation (CTX) is an effective treatment for end-stage heart disease. Cardiac arrhythmias are increasingly recognized and associated with significant morbidity and mortality. We aim to describe the clinical and electrophysiological characteristics of patients with atrial arrhythmias occurring late after CTX. METHODS AND RESULTS: Sixteen patients with prior CTX who presented with late atrial arrhythmias for electrophysiological studies (EPS) were identified at two cardiac transplant centres. Among 859 patients, 16 (mean age 52 ± 14 years, 11 of 16 were men) patients underwent EPS for atrial arrhythmias presenting 8.6 ± 5.7 years following CTX. Among 16 patients, 14 underwent cardiac alone and 2 included lung transplantation. There were no cases of cardiac rejection. Arrhythmias were due to counterclockwise cavotricuspid-dependent atrial flutter (AFL) in 10 of 16, atrial tachycardia (AT) in 6 (1 patient had AFL and AT), and 1 due to atrioventricular nodal re-entrant tachycardia. Recipient-donor atrial electrical connection was seen in two of six AT and in no cases of AFL. In two cases, a focal AT was mapped to the remnant atrium conducting 2 : 1 or at variable block to the donor atrium. In four cases a focal/micro re-entrant AT originated within the vicinity of the interatrial suture scar. All cases were successfully ablated with radiofrequency energy; however, one case of AFL required a repeat ablation. Patients remained free of arrhythmia at 34 ± 15 months post-ablation. CONCLUSION: Typical AFL and AT are the most frequent supraventricular arrhythmias occurring late following CTX. Focal ATs may originate in low-voltage or border zones immediately adjacent to the atrio-atrial anastomosis. Radiofrequency ablation is an effective treatment strategy with high long-term success.

Novel aggregated multiposition noncontact mapping of atrial tachycardia in humans: From computational modeling to clinical validation.

BACKGROUND: A novel aggregated multiposition noncontact mapping (AMP-NCM) algorithm is proposed to diagnose cardiac arrhythmias. OBJECTIVE: The purpose of this study was to computationally determine an accuracy threshold and to compare the accuracy and clinical utility of AMP-NCM to gold standard contact mapping. METHODS: In a cellular automata model, the number of catheter positions and chamber coverage were varied to establish accuracy requirements for clinically relevant AMP-NCM. This guided the clinical study protocol. In a prospective cohort of patients with atrial tachycardia (AT), noncontact mapping (NCM) recordings from a single position (SP) and multiple positions were compared to contact mapping with a high-density multipolar catheter using morphology and timing differences of reconstructed signals. Identification of AT mechanisms and ablation targets using both AMP-NCM and contact mapping were randomly evaluated by 5 blinded reviewers. RESULTS: AMP-NCM accuracy was asymptotic at 60 catheter positions in computational modeling. Twenty patients (age 65 ± 12 years; 19 male) with 26 ATs (5 focal, 21 reentrant) were studied. Morphologic correlation of signals derived from AMP-NCM was significantly better than those from SP-NCM compared to contact signals (median 0.93 vs 0.76; P <.001). AMP-NCM generated maps more rapidly than contact mapping (3 ± 1 minutes vs 13 ± 6 minutes; P <.001) and correctly diagnosed AT mechanisms in 25 of 26 maps (96%). Overall, 80% of arrhythmia mechanisms were correctly identified using AMP-NCM by blinded reviewers. CONCLUSION: Once 60 catheter positions were achieved, AMP-NCM successfully diagnosed mechanisms of AT and identified treatment sites equal to gold standard contact mapping in 3 minutes of procedural time.

Impact of VV optimization in relation to left ventricular lead position: an acute haemodynamic study.

AIMS: Left ventricular (LV) lead placement to the most delayed segment offers the greatest potential benefit to cardiac resynchronization therapy (CRT). We assessed the impact of interventricular (VV) optimization on acute changes in cardiac output (CO) in patients with and without LV pacing of the most delayed segment. METHODS AND RESULTS: In 124 patients, the most delayed segment was defined by speckle tracking radial strain and the LV lead position by biplane fluoroscopy. Patients were classified as either a concordant (LV lead at latest site), adjacent (within one segment), or remote (two or more segments away) LV lead. Atrioventricular (AV) and VV delays were optimized by echocardiography. Cardiac output was measured non-invasively and a >20% increase in CO from baseline (intrinsic) defined acute response. Changes in CO in patients with concordant, adjacent, or remote LV leads were recorded following atrioventricular optimization alone (AV OPT) and after combined AV and VV optimization (AV/VV OPT). Compared with AV OPT pacing, AV/VV OPT produced a greater rise in CO (5.45 ± 1.1 vs. 5.76 ± 1.2 L/min, P< 0.001) and higher acute response rates (48.4 vs. 61.3%, P= 0.041). In adjacent patients, compared with AV OPT pacing, AV/VV OPT settings increased the response rate from 36.4 to 63.6% (P= 0.037). VV optimization had no effect on acute response rates in patients with remote (26.7 vs. 33.3%, P = 0.581) or concordant LV leads (65.6 vs. 72.1%, P = 0.438). CONCLUSION: VV optimization overcomes some but not all of the deleterious effects of a suboptimal LV lead position.

Cardiac resynchronization therapy optimization using noninvasive cardiac output measurement.

AIMS: Noninvasive cardiac output (CO) measurement (NICOM) is a novel method to assess ventricular function and offers a potential alternative for optimization of cardiac resynchronization therapy (CRT) devices. We compared the effect of NICOM-based optimization to no optimization (empiric settings) on CRT outcomes. METHODS: Two hundred and three patients undergoing CRT were assessed in two consecutive nonrandomized groups; an empiric group (n = 54) was programmed to "out of the box" settings with a fixed AV delay of 120 ms and a VV delay of 0 ms; and the optimization group (n = 149) underwent adjustments of both the AV and VV delays according to the greatest improvement in resting CO. The primary endpoints were improvements in left ventricular (LV) volumes and function from baseline at 6 months. Secondary endpoints were change in New York Heart Association (NYHA) class, quality of life score, and 6-minute walk test (6 MWT) performance. RESULTS: After 6 months of CRT, the optimization group had a better clinical response with lower NYHA class (2.1 ± 0.8 vs 2.4 ± 0.8, P = 0.048) and quality of life scores (35 ± 18 vs 42 ± 20, P = 0.045) but no differences in 6-MWT performance (269 ± 110 vs 277 ± 114 m, P = 0.81). Echocardiographic response was also better in the optimization group with lower LV end systolic volume (108 ± 51 vs 126 ± 60 mL, P = 0.048) and higher ejection fraction (30 ± 7 vs 27 ± 8, P = 0.01) compared to empiric settings. CONCLUSION: Device optimization using noninvasive measures of CO is associated with better clinical and echocardiographic response compared to empiric settings.

The impact of the right ventricular lead position on response to cardiac resynchronization therapy.

INTRODUCTION: Left ventricular (LV) lead placement to the latest contracting area (concordant LV lead) is associated with better response to cardiac resynchronization therapy (CRT) compared to a discordant LV lead. However, the effect of the right ventricular (RV) lead site on CRT response is unclear. We investigated the relationship of the RV and LV lead positions on CRT response. METHODS: In 131 CRT patients, the LV lead was positioned preferentially in a lateral or posterolateral vein and the RV lead to either the RV septum (RVS, n = 55) or RV apex (RVA, n = 76). The latest site of contraction was determined with two-dimensional speckle tracking radial strain imaging and patients had a concordant LV lead position if pacing the latest segment, and discordant if not. Response was defined as ≥15% reduction in LV end systolic volume (LVESV) at 6-month follow-up. RESULTS: There were no significant differences in mean reduction of LVESV at follow-up (RVS vs RVA: -23.3 ± 16% vs 22.1 ± 18%, P = 0.70) or rate of responders (58.2% vs 57.9%, P = 0.97) between the two groups. In patients with a concordant LV lead (n = 71), the response rate was significantly higher than those with a discordant lead (76.1% vs 36.7%, P < 0.001). There were no differences in outcomes in patients with a concordant or discordant LV lead according to the RV lead location. CONCLUSION: The extent of LV reverse remodeling following CRT is not related to the RV lead position, but is significantly higher in patients with a concordant LV lead.

Left ventricular lead placement in cardiac resynchronization therapy: where and how?

Cardiac resynchronization therapy (CRT) offers proven benefit to patients with refractory symptomatic chronic heart failure (New York Heart Association Class III or IV), severe left ventricular (LV) systolic dysfunction (LV ejection fraction <35%), and LV dyssynchrony (QRS width >120 ms). Cardiac resynchronization therapy has the potential to improve survival and functional capacity, reduce hospital admissions, and promote LV reverse remodelling. Although difficult to truly evaluate, up to 30% of patients do not attain symptomatic benefit. Factors associated with a poor outcome include inappropriate patient selection, inadequate device programming, presence of myocardial scar, and suboptimal LV lead placement. Left ventricular dyssynchrony is an important determinant of CRT response, although at present no reliable single measure to identify patients beyond QRS width has been identified. In this review, we discuss the effect of LV lead placement to pace the region of maximal dyssynchrony, the impact of total scar burden on response, and the relationship between LV lead position and localized scar. Consideration is also given to prospectively defining placement of the LV lead including surgical epicardial lead positioning.

Characterization of the suitability of coronary venous anatomy for targeting left ventricular lead placement in patients undergoing cardiac resynchronization therapy.

AIMS: Recent studies suggest differences in coronary venous anatomy between patients with ischaemic (I) and non-ischaemic (N) cardiomyopathy. We hypothesize that these differences may affect the potential for left ventricular (LV) lead targeting in patients undergoing cardiac resynchronization therapy. METHODS AND RESULTS: The retrograde contrast venograms were retrospectively reviewed in 133 patients (age 68 +/- 9 years, 101 males). The quantity and distribution of veins were recorded as well as the final lead position. There were no major differences in the distribution of LV lead positions between I and N [posterior vein, 14.0% (I) vs. 15.8% (N); posterolateral vein, 21.1 vs. 18.4%; lateral vein, 59.7 vs. 50.0%; anterolateral vein, 3.5 vs. 13.2%; P= NS]. Excluding the middle and great cardiac veins, in total only 59 of 133 patients had more than one suitable vein as potential targets for LV lead placement (I, 36.8% vs. N, 50.0%; P = 0.16). CONCLUSION: Underlying aetiology does not affect the quantity and distribution of coronary veins available for LV lead placement. The limitations of venous anatomy restrict LV lead placement to a single vein with little scope for site selection in almost half of all the patients. Given these limitations, in many patients, prospective targeting of LV lead placement may require a direct surgical approach.

Non-invasive cardiac output measurements based on bioreactance for optimization of atrio- and interventricular delays.

AIMS: Non-invasive cardiac output monitoring (NICOM) based on bio-reactance offers a portable method to assess ventricular function. Optimization of cardiac resynchronization therapy (CRT) by echocardiography is labour-intensive. We compared the ability of NICOM and echocardiography to facilitate optimum CRT device programming. METHODS AND RESULTS: Forty-seven patients in sinus rhythm were evaluated within 14 days of CRT implantation. The atrio- (AV) and interventricular (VV) delay intervals were incrementally adjusted and at each setting, NICOM and echocardiographic data were recorded. Left ventricular (LV) volumes and function were assessed by echocardiography at baseline and 3 months. Response to CRT was defined as a reduction in LV end-systolic volume (LVESV) by >15%. In all patients, cardiac output (CO) increased significantly at optimized settings compared with baseline (5.66 +/- 1.4 vs. 4.35 +/- 1.1 L/min, P < 0.001). A 20% increase in acute CO following CRT predicted LVESV reduction of >15% with a sensitivity of 81% and specificity of 92% (AUC 0.86). The optimum AV delay determined by NICOM was confirmed by echocardiography in 40 of 47 patients (85%, r = 0.89, P < 0.01) and for VV delay in 39 of 47 patients (83%, r = 0.89, P < 0.01). CONCLUSION: Non-invasive cardiac output monitoring is a simple, reliable, and portable alternative to echocardiography to program CRT devices.

Sudden-onset severe presyncope in a 67-year-old man.

A 67-year-old man presented to the emergency department with sudden onset of severe presyncope. He reported that he had a permanent pacemaker implanted in 2006 following atrioventricular node ablation for persistent atrial fibrillation (AF). After suffering increasing shortness of breath, he underwent upgrade to cardiac resynchronisation therapy (CRT) in 2016. He denied any recent falls, interventions or changes in medication. ECG monitoring showed AF with a broad ventricular escape rhythm at around 25 bpm with pauses of up to 3 s. Placement of a magnet over the device resulted in pacing (figure 1A). The implanted device (Medtronic Syncra C2TR01) was interrogated (figure 1B), and a chest radiograph was obtained (figure 2). heartjnl;105/8/657/F1F1F1Figure 1(A) Twelve-lead ECG demonstrating intrinsic rhythm and pacing after application of magnet. (B) Device interrogation with right ventricular threshold test. heartjnl;105/8/657/F2F2F2Figure 2(C) Anteroposterior chest radiograph demonstrating lead position on admission. QUESTION: What was the cause of this presentation?Noise oversensing on the right ventricular (RV) lead due to lead fracture.The RV septal lead has displaced into the right atrial (RA).RA and RV leads were switched in the can during the CRT upgrade.Increase in threshold of RV and left ventricular (LV) leads resulting in loss of capture.

Ablation of Complex Fractionated Electrograms Improves Outcome in Persistent Atrial Fibrillation of Over 2 Year's Duration.

AIM: There is controversy and sparse data on whether substrate based techniques in addition to pulmonary vein isolation (PVI) confer benefit in the catheter ablation of persistent atrial fibrillation (AF), especially if long standing. We performed an observational study to assess whether substrate based ablation improved freedom from atrial arrhythmia. METHODS: A total of 286 patients undergoing first ablation procedures for persistent AF with PVI only(n = 79), PVI plus linear ablation(n = 85), or PVI plus complex fractionated electrogram (CFAE) and linear ablation(n = 107) were followed. Primary end point was freedom from atrial arrhythmia at one year. RESULTS: Mean duration of pre-procedure time in AF was 28+/-27 months.There were no differences in baseline characteristics between groups except a higher proportion of patients with a severely dilated LA in those receiving PVI+CFAEs+lines. Freedom from atrial arrhythmia was higher with a PVI+CFAE+lines strategy then for PVI alone (HR 1.56, 95% CI: 1.04-2.34, p=0.032) but was not higher with PVI+lines. Benefit of substrate modification was conferred for preprocedure times in AF of over 30 months. The occurrence of atrial tachycardia was higher when lines were added to the ablation strategy (HR 0.08, 95% CI: 0.01-0.59, p=0.014). Freedom from atrial arrhythmia at 1 year was higher with lower patient age, use of general anaesthetic (GA), normal or mildly dilated left atrium and decreasing time in AF. CONCLUSIONS: In patients with long standing persistent AF of over 30 months duration,CFAE ablation resulted in improved freedom from atrial arrhythmia. Increased freedom from atrial arrhythmia occurs in patients who are younger and have smaller atria, and with GA procedures. Linear ablation did not improve outcome and resulted in a higher incidence of atrial tachycardia.

Device complications with addition of defibrillation to cardiac resynchronisation therapy for primary prevention.

OBJECTIVE: In patients indicated for cardiac resynchronisation therapy (CRT), the choice between a CRT-pacemaker (CRT-P) versus defibrillator (CRT-D) remains controversial and indications in this setting have not been well delineated. Apart from inappropriate therapies, which are inherent to the presence of a defibrillator, whether adding defibrillator to CRT in the primary prevention setting impacts risk of other acute and late device-related complications has not been well studied and may bear relevance for device selection. METHODS: Observational multicentre European cohort study of 3008 consecutive patients with ischaemic or non-ischaemic dilated cardiomyopathy and no history of sustained ventricular arrhythmias, undergoing CRT implantation with (CRT-D, n=1785) or without (CRT-P, n=1223) defibrillator. Using propensity score and competing risk analyses, we assessed the risk of significant device-related complications requiring surgical reintervention. Inappropriate shocks were not considered except those due to lead malfunction requiring lead revision. RESULTS: Acute complications occurred in 148 patients (4.9%), without significant difference between groups, even after considering potential confounders (OR=1.20, 95% CI 0.72 to 2.00, p=0.47). During a mean follow-up of 41.4±29 months, late complications occurred in 475 patients, giving an annual incidence rate of 26 (95% CI 9 to 43) and 15 (95% CI 6 to 24) per 1000 patient-years in CRT-D and CRT-P patients, respectively. CRT-D was independently associated with increased occurrence of late complications (HR=1.68, 95% CI 1.27 to 2.23, p=0.001). In particular, when compared with CRT-P, CRT-D was associated with an increased risk of device-related infection (HR 2.10, 95% CI 1.18 to 3.45, p=0.004). Acute complications did not predict overall late complications, but predicted device-related infection (HR 2.85, 95% CI 1.71 to 4.56, p<0.001). CONCLUSIONS: Compared with CRT-P, CRT-D is associated with a similar risk of periprocedural complications but increased risk of long-term complications, mainly infection. This needs to be considered in the decision of implanting CRT with or without a defibrillator.

Adding Defibrillation Therapy to Cardiac Resynchronization on the Basis of the Myocardial Substrate.

BACKGROUND: Patients with nonischemic dilated cardiomyopathy (DCM) may be at lower risk for ventricular arrhythmias compared with those with ischemic cardiomyopathy (ICM). In addition, DCM has been identified as a predictor of positive response to cardiac resynchronization therapy (CRT). OBJECTIVES: The aim of this study was to investigate the impact of an additional implantable cardioverter-defibrillator over CRT, according to underlying heart disease, in a large study group of primary prevention patients with heart failure. METHODS: This was an observational, multicenter, European cohort study of 5,307 consecutive patients with DCM or ICM, no history of sustained ventricular arrhythmias, who underwent CRT implantation with (n = 4,037) or without (n = 1,270) a defibrillator. Propensity-score and cause-of-death analyses were used to compare outcomes. RESULTS: After a mean follow-up period of 41.4 ± 29.0 months, patients with ICM had better survival when receiving CRT with a defibrillator compared with those who received CRT without a defibrillator (hazard ratio for mortality adjusted on propensity score and all mortality predictors: 0.76; 95% confidence interval [CI]: 0.62 to 0.92; p = 0.005), whereas in patients with DCM, no such difference was observed (hazard ratio: 0.92; 95% CI: 0.73 to 1.16; p = 0.49). Compared with recipients of defibrillators, the excess mortality in patients who did not receive defibrillators was related to sudden cardiac death in 8.0% among those with ICM but in only 0.4% of those with DCM. CONCLUSIONS: Among patients with heart failure with indications for CRT, those with DCM may not benefit from additional primary prevention implantable cardioverter-defibrillator therapy, as opposed to those with ICM.