Clinical course of hypertrophic cardiomyopathy patients implanted with a transvenous or subcutaneous defibrillator.

AIMS: The implantable cardioverter-defibrillator (ICD) is a life-saving therapy in patients with hypertrophic cardiomyopathy (HCM) at risk of sudden cardiac death. Implantable cardioverter-defibrillator complications are of concern. The subcutaneous ICD (S-ICD) does not use transvenous leads and is expected to reduce complications. However, it does not provide bradycardia and anti-tachycardia pacing (ATP). The aim of this study was to compare appropriate and inappropriate ICD interventions, complications, disease-related adverse events and mortality between HCM patients implanted with a S- or transvenous (TV)-ICD. METHODS AND RESULTS: Consecutive HCM patients implanted with a S- (n = 216) or TV-ICD (n = 211) were enrolled. Propensity-adjusted cumulative Kaplan-Meier curves and multivariate Cox proportional hazard ratios were used to compare 5-year event-free survival and the risk of events. The S-ICD patients had lower 5-year risk of appropriate (HR: 0.32; 95%CI: 0.15-0.65; P = 0.002) and inappropriate (HR: 0.44; 95%CI: 0.20-0.95; P = 0.038) ICD interventions, driven by a high incidence of ATP therapy in the TV-ICD group. The S- and TV-ICD patients experienced similar 5-year rate of device-related complications, albeit the risk of major lead-related complications was lower in S-ICD patients (HR: 0.17; 95%CI: 0.038-0.79; P = 0.023). The TV- and S-ICD patients displayed similar risk of disease-related complications (HR: 0.64; 95%CI: 0.27-1.52; P = 0.309) and mortality (HR: 0.74; 95%CI: 0.29-1.87; P = 0.521). CONCLUSION: Hypertrophic cardiomyopathy patients implanted with a S-ICD had lower 5-year risk of appropriate and inappropriate ICD therapies as well as of major lead-related complications as compared to those implanted with a TV-ICD. Long-term comparative follow-up studies will clarify whether the lower incidence of major lead-related complications will translate into a morbidity or survival benefit.

Remote monitoring of implantable cardiac monitors in patients with unexplained syncope: Predictors of false-positive alert episodes.

BACKGROUND: Remote monitoring is recommended for patients with implantable cardiac monitors (ICMs), but compared to other cardiac implantable devices, ICMs are less accurate and transmit a higher number of alerts. OBJECTIVE: The aim of this study was to investigate the predictors of false-positive (FP) arrhythmic alerts in patients with unexplained syncope who were implanted with ICM and followed by an automatic remote monitoring system. METHODS: We retrospectively evaluated all consecutive patients who received a long-sensing vector ICM for unexplained syncope between January 2019 to September 2021 at our Syncope Unit. The primary endpoint was the incidence of the first FP episode. The secondary endpoints included assessing the incidence of FP episodes for all types of algorhythms and indentifying the reasons for the misdetection of these episodes. RESULTS: Among 105 patients (44.8% males, median age 51 years), 51 (48.6%) transmitted at least one FP alert during a median follow-up of 301 days. The presence of pre-ventricular complexes (PVCs) on the resting electrocardiogram was the only clinical characteristic associated with an increased risk of FP alerts (adjusted Hazard ratio [HR] 5.76 [2.66-12.4], p = 0.010). The other significant device-related variables were a low-frequency filter at 0.05 Hz versus the default 0.5 Hz (adjusted HR 3.82 [1.38-10.5], p = 0.010) and the R-wave amplitude (adjusted HR 0.35 [0.13-0.99], p = 0.049). CONCLUSION: Patients who have PVCs are at higher risk of inappropriate ICM activations. To reduce the occurrence of FP alerts, it may be beneficial to target a large R-wave amplitude during device insertion and avoid programming a low-frequency filter at 0.05 Hz.

Ablate and pace: Comparison of outcomes between conduction system pacing and biventricular pacing.

BACKGROUND: Conduction system pacing (CSP), including His-bundle pacing (HBP) and left bundle branch area pacing (LBBAP), have been proposed as alternatives to biventricular pacing (BVP) in patients scheduled for ablate and pace (A&P) strategy. The aim of this study was to compare the clinical outcomes, including the rate and nature of device-related complications, between BVP and CSP in a cohort of patients undergoing A&P. METHODS: Prospective, multicenter, observational study, enrolling consecutive patients undergoing A&P. The risk of device-related complications and of heart failure (HF) hospitalization was prospectively assessed. RESULTS: A total of 373 patients (75.3 ± 8.7 years, 53.9% male, 68.9% with NYHA class ≥III) were enrolled: 263 with BVP, 68 with HBP, and 42 with LBBAP. Baseline characteristics of the three groups were similar. Compared to BVP and HBP, LBBAP was associated with the shortest mean procedural and fluoroscopy times and with the lowest acute capture thresholds (all p < .05). At 12-month follow-up LBBAP maintained the lowest capture thresholds and showed the longest estimated residual battery longevity (all p < .05). At 12-months follow-up the three study groups showed a similar risk of device-related complications (5.7%, 4.4%, and 2.4% for BVP, HBP, and LBBAP, respectively; p = .650), and of HF hospitalization (2.7%, 1.5%, and 2.4% for BVP, HBP, and LBBAP, respectively; p = .850). CONCLUSIONS: In the setting of A&P, CSP is a feasible pacing modality, with a midterm safety profile comparable to BVP. LBBAP offers the advantage of reducing procedural times and obtaining lower and stable capture thresholds, with a positive impact on the device longevity.

Air entrapment as a cause of early inappropriate shocks after subcutaneous defibrillator implant: A case series.

Inappropriate shock (IAS) is the most frequent device-related complication among patients with subcutaneous implantable cardioverter-defibrillator (S-ICD). Air entrapment (AE) has been described as an underdiagnosed cause of early postimplant IAS. We report 6 consecutive cases of early IAS after S-ICD implant, in whom the electrogram analysis (EGM) and/or chest radiography (CXR) were consistent with AE.

Impact of atrioventricular junction ablation and CRT-D on long-term mortality in patients with left ventricular dysfunction, permanent, refractory atrial fibrillation, and narrow QRS: Results of a propensity-matched analysis.

INTRODUCTION: In patients with symptomatic permanent atrial fibrillation (PEAF) and narrow QRS, atrio-ventricular junction ablation (AVJA) plus cardiac resynchronization therapy (CRT) is superior to medical therapy in reducing heart failure (HF) hospitalization and all-cause mortality. To compare the mortality of a population of patients with HF, reduced EF (rEF), and PEAF treated with AVJA plus CRT with that of a contemporary cohort of patients in sinus rhythm (SR) with similar baseline characteristics. METHODS AND RESULTS: In this prospective, multicentre, observational study, all-cause mortality in a group of consecutive patients undergoing AVJA and implantable cardioverter-defibrillator (ICD) combined with CRT implantation for HFrEF, narrow QRS, and PEAF with uncontrolled ventricular rate was compared with that of a contemporary cohort of patients in SR undergoing ICD implantation (not combined with CRT) for HFrEF and narrow QRS. Individual 1:1 propensity matching of baseline characteristics was performed. A total of 824 patients were enrolled. Propensity matching yielded 107 matched pairs. After a median follow-up of 52 months, all-cause mortality was similar in patients treated with AVJA plus CRT and in the control group (p = .434). In AVJA plus CRT patients, mortality was significantly lower than in control group patients with a history of paroxysmal/persistent AF (n = 45, p = .020), and similar to that of patients without a history of AF (n = 62, p = .459). CONCLUSIONS: After adjustment for patient characteristics, the long-term prognosis of patients with HFrEF, narrow QRS, and PEAF who underwent AVJA plus CRT was similar to that of a population of patients in SR with similar characteristics.

Add-on Therapy With Sacubitril/Valsartan and Clinical Outcomes in CRT-D Nonresponder Patients.

ABSTRACT: No data on the add-on sacubitril/valsartan (S/V) therapy among cardiac resynchronization therapy with a defibrillator (CRT-D) nonresponder patients are currently available in literature. We conducted a prospective observational study including 190 CRT-D nonresponder patients with symptomatic heart failure with reduced ejection fraction despite the optimal medical therapy from at least 1 year. The primary endpoint was the rate of additional responders (left ventricular end-systolic volume reduction >15%) at 12 months from the introduction of S/V therapy. At the end of the 12 months follow-up, 37 patients (19.5%) were deemed as "additional responders" to the combination use of CRT + S/V therapy. The only clinical predictor of additional response was a lower left ventricular ejection fraction [OR 0.881 (0.815-0.953), P = 0.002] at baseline. At 12 months follow-up, there were significant improvements in heart failure (HF) symptoms and functional status [New York Heart Association 2 (2-3) vs. 1 (1-2), P < 0.001; physical activity duration/day: 10 (8-12) vs. 13 (10-18) hours, P < 0.001]. Compared with the 12 months preceding S/V introduction, there were significant reductions in the rate of HF rehospitalization (35.5% vs. 19.5%, P < 0.001), in atrial tachycardia/atrial fibrillation burden [6.0 (5.0-8.0) % vs. 0 (0-2.0) %, P < 0.001] and in the proportions of patients experiencing ventricular arrhythmias (21.6% vs. 6.3%; P < 0.001). Our results indicate that S/V add-on therapy in CRT-D nonresponder patients is associated with 19.5% of additional responders, a reduction in HF symptoms and rehospitalizations, AF burden, and ventricular arrhythmias.

Rate and impact on patient outcome and healthcare utilization of complications requiring surgical revision: Subcutaneous versus transvenous implantable defibrillator therapy.

INTRODUCTION: Comparison data on management of device-related complications and their impact on patient outcome and healthcare utilization between subcutaneous implantable cardioverter-defibrillator (S-ICD) and transvenous ICD (TV-ICD) are lacking. We designed this prospective, multicentre, observational registry to compare the rate, nature, and impact of long-term device-related complications requiring surgical revision on patient outcome and healthcare utilization between patients undergoing S-ICD or TV-ICD implantation. METHODS AND RESULTS: A total of 1099 consecutive patients who underwent S-ICD or TV-ICD implantation were enrolled. Propensity matching for baseline characteristics yielded 169 matched pairs. Rate, nature, management, and impact on patient outcome of device-related complications were analyzed and compared between two groups. During a mean follow-up of 30 months, device-related complications requiring surgical revision were observed in 20 patients: 3 in S-ICD group (1.8%) and 17 in TV-ICD group (10.1%; p = .002). Compared with TV-ICD patients, S-ICD patients showed a significantly lower risk of lead-related complications (0% vs. 5.9%; p = .002) and a similar risk of pocket-related complications (0.6 vs. 2.4; p = .215) and device infection (0.6% vs. 1.2%; p = 1.000). Complications observed in S-ICD patients resulted in a significantly lower number of complications-related rehospitalizations (median 0 vs. 1; p = .013) and additional hospital treatment days (1.0 ± 1.0 vs. 6.5 ± 4.4 days; p = .048) compared with TV-ICD patients. CONCLUSIONS: Compared with TV-ICD, S-ICD is associated with a lower risk of complications, mainly due to a lower risk of lead-related complications. The management of S-ICD complications requires fewer and shorter rehospitalizations.

Effect of SAcubitril/Valsartan on left vEntricular ejection fraction and on the potential indication for Implantable Cardioverter Defibrillator in primary prevention: the SAVE-ICD study.

PURPOSE: Sacubitril/valsartan has been associated with a positive reverse left ventricular remodelling in patients with heart failure with reduced ejection fraction (HFrEF). These patients may also benefit from an ICD implant. We aimed to assess EF improvement after 6 months of treatment with sacubitril/valsartan, evaluating when ICD as primary prevention was no longer indicated. METHODS: Multicentre, observational, prospective study enrolling all consecutive patients with HFrEF and EF ≤ 35% with an ICD as primary prevention and starting treatment with sacubitril/valsartan (NCT03935087). Resynchronization therapy and patients experiencing appropriate ICD therapies before sacubitril/valsartan were excluded. RESULTS: Two-hundred-and-thirty patients were enrolled (73.9% males, mean age 64.3 ± 12.1 years) After 6 months of treatment, a reduction in left ventricular end-diastolic and end-systolic volumes was noted and LVEF increased from 28.3 ± 5.6% to 32.2 ± 6.5% (p < 0.001). At 6 months, a non-ischemic aetiology of cardiomyopathy and a final dose of sacubitril/valsartan > 24/26 mg twice daily were associated with a higher probability of an absolute increase of > 5% in LVEF. A total of 5.3% of primary prevention patients still had an arrhythmic event in the first 6 months after treatment with sacubitril/valsartan started. CONCLUSIONS: Sacubitril/valsartan improves systolic function in HFrEF, mainly due to reverse left ventricular remodelling. Improvement in EF after 6 months of treatment could help prevent ICD implantation in nearly one out of four patients, with important clinical and economic implications. However, the risk of sudden cardiac death in this recovered HFrEF population has not been thoroughly studied, and the present data should be interpreted only as hypothesis-generating.

Echocardiography in Advanced Heart Failure for Diagnosis, Management, and Prognosis.

Advanced heart failure, an end-stage disease characterized by high mortality and morbidity despite standard medical therapy, requires various therapeutic strategies like heart transplant and long-term mechanical circulatory support. Echocardiography is the main imaging technique to identify transitions to advanced stages of disease and guide risk stratification and therapeutic decision-making processes. Progressive development of advanced echocardiographic techniques allows more comprehensive assessment of the hemodynamic and structural profiles of patients with advanced heart failure, and its use in clinical practice continues to expand. This article provides an overview of basic and emerging echocardiographic tools to assess patients with advanced heart failure.

The role of atrial sensing for new-onset atrial arrhythmias diagnosis and management in single-chamber implantable cardioverter-defibrillator recipients: Results from the THINGS registry.

INTRODUCTION: Atrial tachycardia/fibrillation (AT/AF) episodes are common in implantable cardioverter-defibrillator (ICD) recipients and can be undetected by standard single-chamber devices. This study aims to explore whether a single-lead ICD with an atrial dipole (ICD DX; BIOTRONIK SE & Co, Berlin, Germany) could improve the AT/AF diagnosis and management as compared to standard ICD (ICD VR). METHODS AND RESULTS: We selected patients without AT/AF history from the THINGS registry which included consecutive patients implanted with ICD for standard indications. The ICD VR and the ICD DX groups included 236 (62.8%) and 140 (37.2%) patients, respectively, and had no significant differences in baseline characteristics. During a median follow-up of 27 months, there were 7 AT/AF diagnoses in the ICD VR and 18 in the ICD DX group. The 2-year incidence of AT/AF diagnosis was 3.6% (95% confidence interval [CI]: 1.6%-9.6%) for the ICD VR and 11.4% (95% CI: 6.8%-18.9%) for the ICD DX group (adjusted hazard ratio [HR]: 3.85 [95% CI: 1.58-9.41]; P = .003). Initiation of oral anticoagulation (OAC) due to AT/AF diagnosis was reported in 15 patients. The 2-year incidence of OAC onset was 3.6% (95% CI: 1.6%-7.8%) for the ICD VR and 6.3% (95% CI: 3.0%-12.7%) for ICD DX group (adjusted HR: 1.99 [95% CI: 0.72-5.56]; P = .184). CONCLUSION: We observed that atrial sensing capability in single-chamber ICD patients without evidence of atrial arrhythmias at implant is associated with a greater likelihood of detecting AT/AF episodes. The management of these diagnosed arrhythmias often led to clinical interventions, mainly represented by initiation of OAC therapy.

Atrial Fibrillation in COVID-19: From Epidemiological Association to Pharmacological Implications.

Coronavirus disease 2019 (COVID-19) outbreak is a public health emergency of international concerns because of a highly pathogenic human coronavirus (HCoV), actually named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Despite much emerging data about the epidemiological association between cardiovascular diseases and COVID-19, little is still known about atrial fibrillation and its optimal management in this clinical contest. The aim of our review is to describe the pharmacological interactions between cardiovascular drugs more commonly used in atrial fibrillation management and experimental COVID-19 therapies, based on EU and US summaries of product characteristics.

Risk of syncopal recurrences in patients treated with permanent pacing for bradyarrhythmic syncope: role of correlation between symptoms and electrocardiogram findings.

AIMS: To evaluate the risk of syncopal recurrences after pacemaker implantation in a population of patients with syncope of suspected bradyarrhythmic aetiology. METHODS AND RESULTS: Prospective, multicentre, observational registry enrolling 1364 consecutive patients undergoing pacemaker implantation for syncope of bradyarrhythmic aetiology (proven or presumed). Before pacemaker implantation, all patients underwent a cardiac work-up in order to establish the bradyarrhythmic aetiology of syncope. According to the results of the diagnostic work-up, patients were divided into three groups: Group A, patients in whom a syncope-electrocardiogram (ECG) correlation was established (n = 329, 24.1%); Group B, those in whom clinically significant bradyarrhythmias were detected without a documented syncope-ECG correlation (n = 877, 64.3%); and Group C, those in whom bradyarrhythmias were not detected and the bradyarrhythmic origin of syncope remained presumptive (n = 158, 11.6%). During a median follow-up of 50 months, 213 patients (15.6%) reported at least one syncopal recurrence. Patients in Groups B and C showed a significantly higher risk of syncopal recurrences than those in Group A [hazard ratios (HRs): 1.60 and 2.66, respectively, P < 0.05]. Failure to establish a syncope-ECG correlation during diagnostic work-up before pacemaker implantation was an independent predictor of syncopal recurrence on multivariate analysis (HR: 1.90; P = 0.002). CONCLUSION: In selecting patients with syncope of suspected bradyarrhythmic aetiology for pacemaker implantation, establishing a correlation between syncope and bradyarrhythmias maximizes the efficacy of pacing and reduces the risk of syncopal recurrences.

Real-life outcome of implantable cardioverter-defibrillator and cardiac resynchronization defibrillator replacement/upgrade in a contemporary population: observations from the multicentre DECODE registry.

AIMS: The benefit of prolonged implantable cardioverter-defibrillator (ICD)/cardiac resynchronization therapy defibrillator (CRT-D) therapy following device replacement is hindered by clinical and procedure-related adverse events (AEs). Adverse events rate is highest in more complex devices and at upgrades, as per the REPLACE registry experience, but is changing owing to the improvement in device technology and medical care. We aimed at understanding the extent and type of AEs in a contemporary Italian population. METHODS AND RESULTS: Detect long-term complications after ICD replacement (DECODE) was a prospective, single-arm, multicentre cohort study aimed at estimating medium- to long-term AEs in a large population of patients undergoing ICD/cardiac resynchronization defibrillator replacement/upgrade from 2013 to 2015. We prospectively analysed all clinical and device-related AEs at 12-month follow-up (FU) of 983 consecutive patients (median age 71 years, 76% male, 55% ischaemic, 47% CRT-D) followed for 353 ± 49 days. Seven percent of the patients died (60.6% for cardiovascular reasons), whereas 104 AEs occurred; 43 (4.4%) patients needed at least one surgical action to treat the AE. Adverse events rates were 3.3/100 years lead-related, 3.4/100 years bleedings, and 1.6/100 years infective. The primary endpoint was predicted by hospitalization in the month prior to the procedure [hazard ratio (HR) = 2.23, 1.16-4.29; 0.0169] and by upgrade (HR = 1.75, 1.02-2.99, 0.0441). One hundred and twelve (11.4%) patients met the combined endpoint of death from any cause, cardiac implantable electronic device (CIED)-related infection, and surgical action/hospitalization required to treat the AE. Hospitalization within 30 days prior to the procedure (HR = 2.07, 1.13-3.81; 0.0199), anticoagulation (HR = 1.97, 1.26-3.07; 0.003), and ischaemic cardiomyopathy (HR = 1.67, 95% confidence interval 1.06-2.63; P = 0.0276) were associated with the combined endpoint during FU. CONCLUSIONS: Adverse events following CIED replacement/upgrade are lower than previously reported, possibly owing to improved patients care. Hospitalization in the month prior to the procedure, upgrade, and clinical profile (anticoagulation, ischaemic cardiomyopathy) hint to increased risk, suggesting an individualized planning of the procedure to minimize overall AEs. CLINICAL TRIAL REGISTRATION: URL: http://clinicaltrials.gov/ Identifier: NCT02076789.

Effects of defibrillation shock in patients implanted with a subcutaneous defibrillator: a biomarker study.

Aims: Implantable cardioverter defibrillator (ICD) shocks are associated with a subsequent increased risk of death, and an elevation of cardiac enzymes has been measured after defibrillation testing (DFT). In an experimental swine study, subcutaneous ICD (S-ICD) shocks caused less myocardial damage than traditional ICD shocks. The aim of our study was to investigate the association between S-ICD shock and acute cardiac damage in humans, as evaluated by means of sensitive and highly specific circulating biomarkers. Methods and results: We calculated the variation in the serum levels of high-sensitivity cardiac troponin I (hs-CTnI) and creatine kinase-MB mass concentration (CK-MB mass), measured before and after an S-ICD shock delivered during intraoperative DFT. We also measured the degree of haemodynamic stress, as the variation in the serum levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and copeptin (CP), after the S-ICD shock. We analysed 30 consecutive patients who received an S-ICD and who underwent DFT by means of a single 65 J shock. The levels of biomarkers did not change from baseline to 1 h post-shock, i.e. hs-CTnI (from 0.029 ± 0.005 ng/mL to 0.030 ± 0.005 ng/mL, P = 0.079) and CK-MB mass (from 1.37 ± 0.17 ng/mL to 1.41 ± 0.18, P = 0.080) and remained stable 6 and 24 h after DFT. The plasma NT-proBNP did not change, whereas CP levels were significantly higher at 1 h post-shock evaluation. However, 6 h after DFT, the levels had returned to the baseline and remained stable at 24 h. Conclusion: The S-ICD shock did not seem to cause myocardial injuries. Although CP levels temporarily rose after DFT, they returned to basal levels within 6 h, which suggests that DFT does not have long-term prognostic implications. ICD shocks are associated with a subsequent increased risk of death, and an elevation of cardiac enzymes has been measured after DFT. We showed that serum levels of biomarkers of myocardial damage did not increase after high-energy DFT in patients who had undergone S-ICD device implantation. This suggests that S-ICD shock does not have long-term prognostic implications.

Appropriate implantable cardioverter-defibrillator interventions in cardiac resynchronization therapy-defibrillator (CRT-D) patients undergoing device replacement: time to downgrade from CRT-D to CRT-pacemaker? Insights from real-world clinical practice in the DECODE CRT-D analysis.

Aim: Ventricular tachycardia (VT)/ventricular fibrillation (VF) occurrence after cardiac resynchronization therapy-defibrillator (CRT-D) replacement is unknown; hence, there is no practical guideline to recommend either CRT-D or CRT-pacemaker at the time of device replacement. We observed the 1-year VT/VF occurrence after CRT-D replacement in a subanalysis of the Detect Long-term Complications after ICD Replacement (DECODE) registry. Methods and results: A total of 332 consecutive patients who had undergone CRT-D replacement from 2013 to 2015 were enrolled in 36 Italian centres. The primary endpoint was the number of patients with any appropriate implantable cardioverter-defibrillator (ICD) interventions during 12-month follow-up. The secondary endpoint comprised death from any cause and appropriate ICD interventions. At replacement, 214 (64.5%) patients had a left ventricular ejection fraction ≤ 35% and 138 (41.6%) patients had a secondary prevention indication for ICD. Seventy (21.1%) patients had no longer indication to ICD therapy. During a median follow-up period of 406.5 (362-533) days, VT/VF requiring therapy delivery occurred in 57 (17%) patients, specifically in 7% of those who no longer had an ICD indication. On multivariate analysis, number of criteria for ICD replacement independently predicted appropriate ICD intervention during follow-up [hazard ratio (HR) = 1.62, 95% confidence interval (CI) 1.07-2.46; log-rank P = 0.02]. The combined endpoint of death from any cause or appropriate ICD therapy occurred in 76 (23%) patients. Only NYHA class remained associated with this combined endpoint (HR = 1.97, 95% CI 1.23-3.14; P = 0.005). Conclusions: The DECODE registry showed the 'real-world' experience of CRT-D recipients approaching device replacement, in which 7% of patients who no longer had an indication for ICD therapy experienced appropriate ICD interventions.

Cardiac resynchronization therapy and electrical storm: results of the OBSERVational registry on long-term outcome of ICD patients (OBSERVO-ICD).

Aims: Electrical storm (ES) is a condition defined as three or more episodes of ventricular fibrillation (VF) or ventricular tachycardia (VT) within 24 h, and usually coexist with advanced heart failure in patients with structural heart disease. The aim of the present study is to test whether cardiac resynchronization therapy (CRT) can be associated with a lower incidence of ES. Methods and results: The OBSERVO-ICD (NCT02735811) is a multicentre, retrospective registry, enrolling all consecutive patients undergoing ICD or CRT-D implantation from 2010 to 2012 in five Italian high-volume arrhythmia centres. Propensity score matching was used to compare two equally sized cohorts of ICD and CRT-D patients with similar characteristics. The primary endpoint was the time free from ES. Secondary endpoints were time free from unclustered VT/VF episodes and time free from ES in CRT-D patients according to clinical or echographic response. CRT-D was associated with a 45% relative risk reduction in ES when compared with ICD (5.6% vs. 12.3%; log rank P = 0.014). CRT-responders presented lower rates of ES when compared with non-responders and negative responders according to both clinical and echographic criteria (log-rank P = 0.017 and 0.023, respectively). No ES was detected in any of the 133 full responders to CRT-D. Clinical and echographic positive responses, but not CRT-implant per se, were associated with lower estimate rates of unclustered VTs/VFs. Conclusion: Patients with CRT had a lower incidence of ES when compared with propensity-matched ICD patients. The long-term benefit of CRT seems to be due to the improved haemodynamics, as CRT-responders performed markedly better over a long-term follow-up.

Management of Bradyarrhythmias in Heart Failure: A Tailored Approach.

Patients with heart failure (HF) may develop a range of bradyarrhythmias including sinus node dysfunction, various degrees of atrioventricular block, and ventricular conduction delay. Device implantation has been recommended in these patients, but the specific etiology should be sought as it may influence the choice of the type of device required (pacemaker vs. implantable cardiac defibrillator). Also, pacing mode must be carefully set in patients with heart failure (HF) and left ventricular systolic dysfunction.In this chapter, we summarize the knowledge required for a tailored approach to bradyarrhythmias in patients with heart failure.

Effect of fixed-rate vs. rate-RESPONSIve pacing on exercise capacity in patients with permanent, refractory atrial fibrillation and left ventricular dysfunction treated with atrioventricular junction aBLation and bivEntricular pacing (RESPONSIBLE): a prospective, multicentre, randomized, single-blind study.

AIMS: Atrioventricular junction (AVJ) ablation followed by biventricular pacing is an established strategy for improving symptoms and morbidity in patients with permanent atrial fibrillation (AF), reduced left ventricular ejection fraction (LVEF), and uncontrolled ventricular rate. There is no clear evidence that such patients benefit from rate-responsive (RR) pacing. METHODS AND RESULTS: This prospective, randomized, single-blind, multicentre study was designed as an intra-patient comparison and enrolled 60 patients (age 69.5 ± 11.8 years, males 63.3%, NYHA 3.0 ± 0.6) with refractory AF and reduced LVEF (mean 32.4 ± 8.3%) treated with AVJ ablation and biventricular pacing. Two 6-minute walking tests (6MWT) were performed 1 week apart: one during VVI 70/min biventricular pacing and the other during VVIR 70-130/min biventricular pacing; patients were randomly and blindly assigned to Group A (n = 29, first 6MWT in VVIR mode) or B (n = 31, first 6MWT in VVI mode). Rate-responsive activation determined an increase of 18.8 ± 24.4 m in the distance walked during the 6MWT (P < 0.001). The increase was similar in both groups (P = 0.571). A >5% increase in the distance walked was observed in 76.7% of patients. The increase in the distance walked was linearly correlated with the increase in heart rate recorded during the 6MWT in the VVIR mode (r = 0.54; P < 0.001). CONCLUSION: In permanent AF patients with uncontrolled rate and reduced LVEF who had undergone AVJ ablation and biventricular pacing, RR pacing yields a significant gain in exercise capacity, which seems to be related to the RR-induced frequency during effort.

Economic impact of remote monitoring after implantable defibrillators implantation in heart failure patients: an analysis from the EFFECT study.

AIMS: Heart failure (HF) patients with implantable cardioverter-defibrillators (ICD) require admissions for disease management and out-patient visits for disease management and assessment of device performance. These admissions place a significant burden on the National Health Service. Remote monitoring (RM) is an effective alternative to frequent hospital visits. The EFFECT study was a multicentre observational investigation aiming to evaluate the clinical effectiveness of RM compared with in-office visits standard management (SM). The present analysis is an economic evaluation of the results of the EFFECT trial. METHODS AND RESULTS: The present analysis considered the direct consumption of healthcare resources over 12-month follow-up. Standard tariffs were applied to hospitalizations, in-office visits and remote device interrogations. Economic comparisons were also carried out by means of propensity score (PS) analysis to take into account the lack of randomization in the study design. The analysis involved 858 patients with ICD or CRT-D. Of these, 401 (47%) were followed up via an SM approach, while 457 (53%) were assigned to RM. The rate of hospitalizations was 0.27/year in the SM group and 0.16/year in the RM group (risk reduction =0.59; P = 0.0004). In the non-adjusted analysis, the annual cost for each patient was €817 in the SM group and €604 in the RM group (P = 0.014). Propensity score analysis, in which 292 RM patients were matched with 292 SM patients, confirmed the results of the non-adjusted analysis (€872 in the SM group vs. €757 in the RM group; P < 0.0001). CONCLUSION: There is a reduction in direct healthcare costs of RM for HF patients with ICDs, particularly CRT-D, compared with standard monitoring. CLINICAL TRIAL REGISTRATION: http://clinicaltrials.gov/Identifier, NCT01723865.

Clinically guided pacemaker choice and setting: pacemaker expert programming study.

AIM: The aim of this multicentre, observational, transversal study was to evaluate pacemaker (PM) choice and setting in a large number of patients, in order to understand their relationship with the patients' clinical characteristics. METHODS AND RESULTS: The study enrolled a total of 1858 patients (71 ± 14 years, 54% male), consecutively evaluated during scheduled PM follow-up visits in 7 Italian cardiac arrhythmia centres. To evaluate the appropriateness of PM choice in relation to the patients' clinical characteristics, we analysed their rhythm disorders at the time of device implantation and the characteristics of the devices implanted. To evaluate the appropriateness of device setting, current rhythm disorders and device setting at the time of enrolment were analysed. In the overall study population, 64.3% of the patients received a PM with all of the features required for their rhythm disorder [80.8% in persistent atrioventricular (AV) block, 76.5% in atrial fibrillation needing pacing, 71.0% in sinus node disease, 58.7% in non-persistent atrioventricular block (AVB), 52.7% in neuro-mediated syncope]. The most frequent cause of inappropriate PM choice was the lack of an algorithm to promote intrinsic AV conduction in non-persistent AVB patients (38.1%). In 76.2% of the patients with an appropriate PM (n = 1301), the PM was optimally set for their rhythm disorder. CONCLUSIONS: In the present 'real-world' registry, a large number of patients (35.7%) did not receive an optimal PM for their rhythm disorders. Moreover, one-fourth of appropriate PMs were not programmed according to the patients' clinical characteristics.