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.

Predicting all-cause mortality by means of a multisensor implantable defibrillator algorithm for heart failure monitoring.

BACKGROUND: The HeartLogic algorithm (Boston Scientific) has proved to be a sensitive and timely predictor of impending heart failure (HF) decompensation. OBJECTIVE: The purpose of this study was to determine whether remotely monitored data from this algorithm could be used to identify patients at high risk for mortality. METHODS: The algorithm combines implantable cardioverter-defibrillator (ICD)-measured accelerometer-based heart sounds, intrathoracic impedance, respiration rate, ratio of respiration rate to tidal volume, night heart rate, and patient activity into a single index. An alert is issued when the index crosses a programmable threshold. The feature was activated in 568 ICD patients from 26 centers. RESULTS: During median follow-up of 26 months [25th-75th percentile 16-37], 1200 alerts were recorded in 370 patients (65%). Overall, the time IN-alert state was 13% of the total observation period (151/1159 years) and 20% of the follow-up period of the 370 patients with alerts. During follow-up, 55 patients died (46 in the group with alerts). The rate of death was 0.25 per patient-year (95% confidence interval [CI] 0.17-0.34) IN-alert state and 0.02 per patient-year (95% CI 0.01-0.03) OUT of the alert state, with an incidence rate ratio of 13.72 (95% CI 7.62-25.60; P <.001). After multivariate correction for baseline confounders (age, ischemic cardiomyopathy, kidney disease, atrial fibrillation), the IN-alert state remained significantly associated with the occurrence of death (hazard ratio 9.18; 95% CI 5.27-15.99; P <.001). CONCLUSION: The HeartLogic algorithm provides an index that can be used to identify patients at higher risk for all-cause mortality. The index state identifies periods of significantly increased risk of death.

Impact of synchronous atrioventricular delay optimization on left ventricle flow force angle evaluated by echocardiographic particle image velocimetry.

PURPOSE: To evaluate the improvement in electrical synchrony and left ventricle (LV) hemodynamics provided by combining the dynamic atrioventricular delay (AVD) of SyncAVTM CRT and the multiple LV pacing sites of MultiPoint pacing (MPP). METHODS: Patients with LBBB and QRS duration (QRSd) > 140 ms implanted with a CRT-D or CRT-P device and quadripolar LV lead were enrolled in this prospective study. During a post-implant follow-up visit, QRSd was measured from 12-lead surface electrograms by experts blinded to pacing configurations. QRSd reduction relative to intrinsic rhythm was evaluated during biventricular pacing (BiV) and MPP for two AVDs: nominal (140/110 ms paced/sensed) and SyncAV (patient-optimized SyncAV offset [10-60 ms] minimizing QRSd). Echocardiography particle imaging velocimetry (Echo-PIV) analysis was performed for each configuration. The resulting hemodynamic force LV flow angle (φ) was analyzed, which ranges from 0o (predominantly base-apex forces) to 90o (predominantly transverse forces). Higher angles indicate more energy dissipation at lateral walls due to transverse flow; lower angles indicate healthier flow aligned with the longitudinal base-apex path of the pressure gradient. RESULTS: Twelve patients (58% male, 17% ischemic, 32±7% ejection fraction, 165 ± 18 ms intrinsic QRSd) completed QRSd and Echo-PIV assessment. Relative to intrinsic rhythm, BiV and MPP with nominal AVD reduced QRSd by 10 ± 9% and 12 ± 9%, respectively. BiV+SyncAV and MPP+SyncAV further reduced QRSd by 19 ± 8%, (p < 0.05 vs. BiV with nominal AVD) and 23 ± 9% (p < 0.05 vs BiV+SyncAV), respectively. Echo-PIV showed similar sequential hemodynamic improvements. LV flow angular orientation during intrinsic activation (46 ± 3o) reduced with BiV+SyncAV (37 ± 4o, p < 0.05 vs intrinsic) and further with MPP+SyncAV (34 ± 4o, p < 0.05 vs BiV+SyncAV). CONCLUSION: These results suggest that SyncAV may improve electrical synchrony and influence LV flow patterns in patients suffering from heart failure compared to conventional CRT with a fixed AVD, with further improvement observed by combining with MPP.

Device-Related Complications and Inappropriate Therapies Among Subcutaneous vs. Transvenous Implantable Defibrillator Recipients: Insight Monaldi Rhythm Registry.

Introduction: In the context of randomized clinical trials, subcutaneous implantable cardiac defibrillators (S-ICDs) are non-inferior to transvenous ICDs (T-ICDs) concerning device-related complications or inappropriate shocks in patients with an indication for defibrillator therapy and not in need of pacing. We aimed at describing the clinical features of patients who underwent S-ICD implantation in our clinical practice, as well as the ICD-related complications and the inappropriate therapies among S-ICD vs. T-ICD recipients during a long-term follow-up. Materials and Methods: All patients undergoing ICD, both S-ICD and TV-ICD, at Monaldi Hospital from January 1, 2015 to January 1, 2019 and followed up at our institution were included in the present analysis. The clinical variables associated with S-ICD implantation were evaluated by logistic regression analyses. We collected the ICD inappropriate therapies, ICD-related complications (including both pulse generator and lead-related complications), ICD-related infections, appropriate ICD therapies, and overall mortality. Kaplan-Meier (KM) analyses were performed to assess the risk of clinical outcome events between the two subgroups. A time-dependent Cox regression analysis was performed to adjust the results. Results: Total 607 consecutive patients (mean age 53.8 ± 16.8, male 77.8%) with both TV-ICD (n: 290, 47.8%) and S-ICD (n: 317, 52.2%), implanted and followed at our center for a mean follow-up of 1614 ± 1018 days, were included in the study. At multivariate logistic regression analysis, an independent association between S-ICD implantation and ionic channel disease [OR: 6.01 (2.26-15.87); p < 0.0001] and ischemic cardiomyopathy [OR: 0.20 (0.12-0.35); p < 0.0001] was shown. The KM analysis did not show a significantly different risk of the inappropriate ICD therapies (log rank p = 0.64) between the two subgroups; conversely, a significant increase in the risk of ICD-related complications (log rank p = 0.02) and infections (log rank p = 0.02) in TV-ICD group was shown. The adjusted risk for ICD-related infections [OR: 0.07 (0.009-0.55), p = 0.01] and complications [0.31 (0.12-0.81), p = 0.01] was significantly lower among patients with S-ICD. Conclusions: The choice to implant S-ICD was mainly driven by younger age and the presence of ionic channel disease; conversely ischemic cardiomyopathy reduces the probability to use this technology. No significant differences in inappropriate ICD therapies were shown among S-ICD vs. TV-ICD group; moreover, S-ICD is characterized by a lower rate of infectious and non-infectious complications leading to surgical revision or extraction.

Early evaluation of atrial high rate episodes using remote monitoring in pacemaker patients: Results from the RAPID study.

Aim: Remote monitoring (RM) of implantable cardiac devices has enabled continuous surveillance of atrial high rate episodes (AHREs) with well-recognized clinical benefits. We aimed to add evidence on the role of the RM as compared to conventional follow-up by investigating the interval from AHRE onset to physician's evaluation and reaction time in actionable episodes. Methods and Results: A total of 97 dual-chamber pacemaker recipients were followed with RM (RM-ON group; N = 64) or conventional in-office visits (RM-OFF group; N = 33) for 18 months. In-office visits were scheduled at 1, 6, 12, and 18 months in the RM-OFF group and at 1 and 18 months in the RM-ON group. The overall AHRE rate was 1.98 per patient-year (95% confidence interval [CI], 1.76-2.20) with no difference between the two groups (RM-ON vs. RM-OFF weighted-HR, 0.88; CI, 0.36-2.13; p = .78). In the RM-ON group, 100% AHREs evaluated within 11 days from onset, and within 202 days in the RM-OFF group, with a median evaluation delay 79 days shorter in the RM-ON group versus the RM-OFF group (p < .0001). Therapy adjustment in actionable AHREs occurred 77 days earlier in the RM-ON group versus the control group (p < .001). In the RM-ON group, there were 50% less in-office visits as compared to the RM-OFF group (p < .001). Conclusions: In our pacemaker population with no history of atrial fibrillation, RM allowed significant reduction of AHRE evaluation delay and prompted treatment of actionable episodes as compared to biannual in-office visit schedule.

Implantable defibrillator-detected heart failure status predicts atrial fibrillation occurrence.

BACKGROUND: In heart failure (HF) patients, atrial fibrillation (AF) is associated with a worse prognosis. Implantable cardioverter-defibrillator (ICD) diagnostics allow continuous monitoring of AF and are equipped with algorithms for HF monitoring. OBJECTIVE: We evaluated the association between the values of the multisensor HF HeartLogic index and the incidence of AF, and assessed the performance of the index in detecting follow-up periods of significantly increased AF risk. METHODS: The HeartLogic feature was activated in 568 ICD patients. Median follow-up was 25 months [25th-75th percentile (15-35)]. The HeartLogic algorithm calculates a daily HF index and identifies periods of IN-alert state on the basis of a configurable threshold. The endpoints were daily AF burden ≥5 minutes, ≥6 hours, and ≥23 hours. RESULTS: The HeartLogic index crossed the threshold value 1200 times. AF burden ≥5 minutes/day was documented in 183 patients (32%), ≥6 hours/day in 118 patients (21%), and ≥23 hours/day in 89 patients (16%). The weekly time of IN-alert state was independently associated with AF burden ≥5 minutes/day (hazard ratio [HR] 1.95; 95% confidence interval [CI] 1.22-3.13; P = .005), ≥6 hours/day (HR 2.66; 95% CI 1.60-4.44; P <.001), and ≥23 hours/day (HR 3.32; 95% CI 1.83-6.02; P <.001), after correction for baseline confounders. Comparison of the episode rates in the IN-alert state with those in the OUT-of-alert state yielded HR ranging from 1.57 to 3.11 for AF burden from ≥5 minutes to ≥23 hours. CONCLUSIONS: The HeartLogic alert state was independently associated with AF occurrence. The intervals of time defined by the algorithm as periods of increased risk of HF allow risk stratification of AF according to various thresholds of daily burden.

Design and rationale of the Impact of MultiPoint pacing in CRT patients with reduced RV-to-LV delay (IMAGE-CRT) study.

BACKGROUND: Cardiac resynchronization therapy (CRT) is an established treatment in patients with heart failure and prolonged QRS duration. A biventricular device is implanted to achieve faster activation and more synchronous contraction of the ventricles. Despite the convincing effect of CRT, 30-40% of patients do not respond. We decided to investigate the role of multipoint pacing (MPP) in a selected group of patients with right ventricle (RV)-to-left ventricle (LV) intervals less than 80 ms that do not respond to traditional CRT. METHODS: We will enrol 248 patients in this patient-blinded, observational, clinical study aiming to investigate if MPP could decrease LV end-systolic volume (ESV) in patients with RV-to-LV interval less than 80 ms. MPP will be activated ON at implant in patients with RV-to-LV delay less than 80 ms and OFF in RV-to-LV at least 80 ms. At follow-up the activation of MPP will be related to CRT response. The primary study endpoint will be the responder rate at 6 months, defined as a decrease in LV ejection fraction, LV end-diastolic volume, LV end-systolic volume (LVESV) at least 15% from baseline. Secondary outcomes include 12 months relative percentage reduction in LVESV and a combined clinical outcome measure of response to CRT defined as the patient being alive, no hospitalization due to heart failure, and experiencing an improvement in New York Heart Association functional class (Composite-Score). CONCLUSION: Reducing the nonresponder rate continues to be an important goal for CRT.If an increase in reverse remodelling can be achieved by MPP, this study supports the conduct of larger trials investigating the role of MPP on clinical outcomes in selected patients treated, right now, only with traditional CRT. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02713308. Registered on 18 March 2016.

Time to therapy delivery and effectiveness of the subcutaneous implantable cardioverter-defibrillator.

BACKGROUND: At the time of subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation, successful termination of ventricular fibrillation (VF) is confirmed. A previous study reported cases of prolonged time to therapy during defibrillation testing. OBJECTIVES: We sought to evaluate the time to therapy, identify possible predictors of delay, and investigate the impact of delayed therapy on VF conversion. METHODS: We analyzed consecutive patients with S-ICDs who underwent initial conversion testing at a shock energy of 65 J in 53 Italian centers. RESULTS: We analyzed 570 patients (467 [82%] male; mean age 48 ± 15 years; mean body mass index 25 ± 6 kg/m2; mean ejection fraction 47% ± 17%). General anesthesia was used in 165 (29%) of patients, with sub- or intermuscular positioning of the generator in (422; 74%). Cardioversion was successful at 65 J in 557 (97.7%) of patients. In 12 patients (2.1%) the shock did not convert VF, and in 1 patient the shock was not delivered because of noise from entrapped subcutaneous air. All failures were successfully managed by reprogramming or repositioning the device. The mean time to therapy was 15 ± 3 seconds, and it exceeded 18 seconds in 51 patients (9%). Independent predictors of delayed therapy (18 seconds) were ejection fraction (odds ratio [OR] 0.98; 95% confidence interval [CI] 0.96-0.99; P = .016) and a 2× gain programmed (OR 3.66; 95% CI 1.44-9.30; P = .006). Effectiveness at 65 J was not associated with time to therapy (OR 1.13; 95% CI 0.97-1.32; P = .122). CONCLUSION: In this analysis of a large population of patients with S-ICDs, delayed therapy during defibrillation testing occurred less frequently than previously reported and had no effect on VF conversion success. Delayed therapies seemed more common when a vector with a 2× gain was programmed.

Budget impact analysis of rivaroxaban vs. warfarin anticoagulation strategy for direct current cardioversion in non-valvular atrial fibrillation patients: the MonaldiVert Economic Study.

BACKGROUND: Rivaroxaban is the first novel oral anticoagulant to receive regulatory approval for non-valvular atrial fibrillation (NVAF) patients who require cardioversion. The MonaldiVert real life experience showed positive benefit-risk profile of short term rivaroxaban administration for transesophageal echocardiogram guided cardioversion in patients who had not achieved adequate pre-procedural vitamin K antagonist (VKA) anticoagulation. METHODS: Aim of our study was to perform a budget impact analysis of MonaldiVert anticoagulation strategy for direct current cardioversion in NVAF patients and to compare the following costs borne by the Regional Healthcare System (RHS) with those for a hypothetical cohort of identical patients underwent from the beginning to early rivaroxaban treatment before direct current cardioversion. RESULTS: The mean costs per each NVAF patient treated with VKA strategy and rivaroxaban rescue strategy were € 134.53 and € 189.83, respectively. Considering a hypothetical scenario in which all study population would be treated from the beginning with rivaroxaban (rivaroxaban early strategy), the mean cost per patient would have been € 81.11. The total cost borne by the RHS, including the cost of the cardioversion procedure, for the two therapeutic strategies carried out at Monaldi Hospital (VKA strategy and Rivaroxaban rescue strategy) was € 88,458.53. The total cost would be borne by the RHS for rivaroxaban early strategy, if applied to all study population, would have been € 69,989.15 with a saving of € 18,469.38 compared to the actually applied strategy. CONCLUSIONS: Rivaroxaban rescue strategy for transesophageal echocardiography guided direct current cardioversion in NVAF patients, who had not achieved adequate pre-procedural VKA anticoagulation, is an effective and safe strategy, which allows to not delay the procedure, reducing times and wastage of cardioversion slots, without substantial costs increase.

Remote Monitoring of Atrial High Rate Episodes in Pacemaker Patients. The Rapid Study Design.

BACKGROUND: Remote Monitoring (RM) has been introduced for several years and nowadays most pacemakers are equipped with such a technology. RM can provide early detection of high atrial rate episodes (AHREs) onset and enable prompt medical intervention. However, there are still little data on the clinical reactions triggered by the AHRE detected by RM of pacemaker recipients and on their possible benefit on patients' outcome. METHODS/DESIGN: The RAPID study is a multicenter, prospective, non-interventional study designed to compare the time from onset to first physician's evaluation of AHRE episode with arrhythmic burden ≥5% (72 minutes) for pacemaker recipients without atrial fibrillation history, between patients followed with RM or conventionally with annual in-hospital visits. A total of 98 patients with implanted dual-chamber pacemaker, assigned to RM-OFF or RM-ON according to ordinary clinical site practice, will be followed for a total of 18 months. After the implant, patients will perform their first in-hospital follow-up visit at 1 month and then, in the RM-OFF group, patients will perform an in-hospital FU every 6 months, while in the active group, patients will be continuously monitored via RM until study termination. All AHREs and consequent medical interventions will be collected over the entire study period. DISCUSSION: The ongoing RAPID study will provide additional information on the role of RM in the management of AHRE detected in pacemaker patients without documented atrial fibrillation history in ordinary clinical practice.

[Cardiac resynchronization therapy: mortality, rehospitalization, and procedure-related complications. A three-year single-center observational study within the Italian Health System]. / Resincronizzazione cardiaca: morte, riospedalizzazione e complicanze correlate all'impianto. Studio osservazionale triennale in un singolo centro del Sistema Sanitario Nazionale.

BACKGROUND: The aim of this study was to evaluate whether the benefit of cardiac resynchronization therapy with an implantable defibrillator (CRT-D) may differ among classes of indications to device therapy. METHODS: All-cause mortality, first hospitalization for non-fatal heart failure, stable improvement of NYHA functional class (responders), and implant-related complications were evaluated retrospectively in 103 patients selected among those (n = 133) who received consecutively CRT-D between 2006 and 2009. Patients were divided into three groups: group IA (n = 65) included patients receiving CRT-D for a class IA indication; group IIa (n = 26) included patients with atrial fibrillation and QRS ≥ 130 ms receiving CRT-D for a class IA indication; nonconventional group (NC) (n = 12) included patients with an indication to defibrillator implantation extended to CRT-D because of NYHA class III-IV and echocardiographic evidence of electromechanical dyssynchrony. Echocardiographic examination was performed in all patients to identify wall target for left-side lead placement. RESULTS: Group IIa patients were slightly older than group IA patients (p<0.05); gender distribution, left ventricular ejection fraction at implantation, ischemic etiology, and heart failure treatment were comparable among groups (all p>0.5), except for a higher digitalis use in group IIa patients (p<0.05). In a mean observation period of 3 years (up to December 2010), the rates of fatal events (IA: 22%, IIa: 23%, NC: 20%), rehospitalization for worsening heart failure (IA: 30%, IIa: 33%, NC: 22%), clinical responders (IA: 78%, IIa: 78%, NC: 78%), implant-related complications requiring reintervention (IA: 15%, IIa: 19%, NC: 25%), including pocket or catheter infections (IA: 5%, IIa: 11%, NC: 8%) were comparable among groups (all p>0.5). CONCLUSIONS: In the "real world", the benefit of CRT-D in advanced heart failure patients might be comparable among class IA, IIa or NC indication.