Implantable defibrillator-detected heart failure status predicts ventricular tachyarrhythmias.

INTRODUCTION: The prediction of ventricular tachyarrhythmias among patients with implantable cardioverter defibrillators is difficult with available clinical tools. We sought to assess whether in patients with heart failure (HF) and reduced ejection fraction with defibrillators, physiological sensor-based HF status, as summarized by the HeartLogic index, could predict appropriate device therapies. METHODS: Five hundred and sixty-eight consecutive HF patients with defibrillators (n = 158, 28%) or cardiac resynchronization therapy-defibrillators (n = 410, 72%) were included in this prospective observational multicenter analysis. The association of both HeartLogic index and its physiological components with defibrillator shocks and overall appropriate therapies was assessed in regression and time-dependent Cox models. RESULTS: Over a follow-up of 25 (15-35) months, 122 (21%) patients received an appropriate device therapy (shock, n = 74, 13%), while the HeartLogic index crossed the threshold value (alert, HeartLogic ≥ 16) 1200 times (0.71 alerts/patient-year) in 370 (65%) subjects. The occurrence of ≥1 HeartLogic alert was significantly associated with both appropriate shocks (Hazard ratios [HR]: 2.44, 95% confidence interval [CI]: 1.49-3.97, p = .003), and any appropriate defibrillator therapies. In multivariable time-dependent Cox models, weekly IN-alert state was the strongest predictor of appropriate defibrillator shocks (HR: 2.94, 95% CI: 1.73-5.01, p < .001) and overall therapies. Compared with stable patients, patients with appropriate shocks had significantly higher values of HeartLogic index, third heart sound amplitude, and resting heart rate 30-60 days before device therapy. CONCLUSION: The HeartLogic index is an independent dynamic predictor of appropriate defibrillator therapies. The combined index and its individual physiological components change before the arrhythmic event occurs.

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.

Association Between Device-Detected Sleep-Disordered Breathing and Implantable Defibrillator Therapy in Patients With Heart Failure.

BACKGROUND: Sleep-disordered breathing is highly prevalent in heart failure (HF) and has been suggested as a risk factor for malignant ventricular arrhythmias. The Respiratory Disturbance Index (RDI) computed by an implantable cardioverter-defibrillator (ICD) algorithm accurately identifies severe sleep apnea. OBJECTIVES: In the present analysis, the authors evaluated the association between ICD-detected sleep apnea and the incidence of appropriate ICD therapies in patients with HF. METHODS: We enrolled 411 HF patients who had received an ICD endowed with an algorithm that calculates the RDI each night. In this analysis, the weekly mean RDI value was considered. The endpoint was the first appropriate ICD shock. RESULTS: The median follow-up was 26 months (25th to 75th percentile: 16-35 months). During follow-up, 1 or more ICD shocks were documented in 58 (14%) patients. Patients with shocks were younger (age 66 ± 13 years vs 70 ± 10 years; P = 0.038), and had more frequently undergone implantation for secondary prevention (21% vs 10%; P = 0.026). The maximum RDI value calculated during the entire follow-up period did not differ between patients with and without shocks (55 ± 15 episodes/h vs 54 ± 14 episodes/h; P = 0.539). However, the ICD-detected RDI showed considerable variability during follow-up. The overall median of the weekly RDI was 33 episodes/h (25th to 75th percentile: 24-45 episodes/h). A time-dependent Cox regression model revealed that a continuously measured weekly mean RDI of ≥45 episodes/h was independently associated with shock occurrence (HR: 4.63; 95% CI: 2.54-8.43; P < 0.001), after correction for baseline confounders (age, secondary prevention). CONCLUSIONS: In HF patients, appropriate ICD shocks were more likely to be delivered during periods when patients exhibited more sleep-disordered breathing. (Arrhythmias Detection in a Real World Population [RHYTHM DETECT]; NCT02275637).

Effects of COVID-19 lockdown on arrhythmias in patients with implantable cardioverter-defibrillators in southern Italy.

Background: The effects of lockdown on non-COVID patients are varied and unexpected. The aim is to evaluate the burden of cardiac arrhythmias during a lockdown period because of COVID-19 pandemics in a population implanted with cardiac defibrillators and followed by remote monitoring. Methods: In this retrospective, multicentre cohort study, we included 574 remotely monitored implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy-defibrillator (CRT-D) recipients implanted before January 1, 2019, at seven hospitals in the Campania region, comparing the burden of arrhythmias occurred during the lockdown period because of COVID-19 epidemics (from March 9 to May 1, 2020) with the arrhythmias burden of the corresponding period in 2019 (reference period). Data collection was performed through remote monitoring. Results: During the lockdown period, we observed ventricular tachyarrhythmias (ventricular tachycardia or fibrillation) in 25 (4.8%) patients while in seasonal reference period we documented ventricular tachyarrhythmias in 12 (2.3%) patients; the comparison between the periods is statistically significant (P < .04). Atrial arrhythmias were detected in 38 (8.2%) subjects during the lockdown period and in 24 (5.2%) during the reference period (P < .004). Conclusion: In seven hospitals in the Campania region, during the pandemic lockdown period, we observed a higher burden of arrhythmic events in ICD/CRT-D patients through device remote monitoring.

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.

Decongestive treatment adjustments in heart failure patients remotely monitored with a multiparametric implantable defibrillators algorithm.

AIMS: HeartLogic algorithm combines data from multiple implantable defibrillators (ICD)-based sensors to predict impending heart failure (HF) decompensation. A treatment protocol to manage algorithm alerts is not yet known, although decongestive treatment adjustments are the most frequent alert-triggered actions reported in clinical practice. We describe the implementation of HeartLogic for remote monitoring of HF patients, and we evaluate the approach to diuretic dosing and timing of the intervention in patients with device alerts. METHODS: The algorithm was activated in 229 ICD patients at eight centers. The median follow-up was 17 months (25th-75th percentile: 11-24). Remote data reviews and patient phone contacts were undertaken at the time of HeartLogic alerts, to assess the patient's status and to prevent HF worsening. We analyzed alert-triggered augmented HF treatments, consisting of isolated increases in diuretics dosage. RESULTS: We reported 242 alerts (0.8 alerts/patient-year) in 123 patients, 137 (56%) alerts triggered clinical actions to treat HF. The HeartLogic index decreased after the 56 actions consisting of diuretics increase. Specifically, alerts resolved more quickly when the increases in dosing of diuretics were early rather than late: 28 days versus 62 days, p < .001. The need of hospitalization for further treatments to resolve the alert condition was associated with higher HeartLogic index values on the day of the diuretics increase (odds ratio: 1.11, 95% CI: 1.02-1.20, p = .013) and with late interventions (odds ratio: 5.11, 95% CI: 1.09-24.48, p = .041). No complications were reported after drug adjustments. CONCLUSIONS: Decongestive treatment adjustments triggered by alerts seem safe and effective. The early use of decongestive treatment and the use of high doses of diuretics seem to be associated with more favorable outcomes.

A mobile app for improving the compliance with remote management of patients with cardiac implantable devices: a multicenter evaluation in clinical practice.

BACKGROUND: The remote device management (RM) is recommended for patients with cardiac implantable electronic devices (CIEDs). RM underutilization is frequently driven by the lack of correct system activation. The MyLATITUDE Patient App (Boston Scientific) has been developed to encourage patient compliance with RM by providing information on communicator setup, troubleshooting, and connection status of the communicator. METHODS: At 14 centers, patients with CIEDs were invited to download and install the App on a mobile device. After 3 months, patients were asked to complete an ad hoc questionnaire to evaluate their experience. RESULTS: The App was proposed to 242 consecutive patients: 81 before RM activation, and 161 during follow-up. The App was successfully installed by 177 (73%) patients. The time required for activation of the communicator and the need for additional support were similar between patients who followed the indications provided by the App and those who underwent standard in-clinic training. During follow-up, notifications of lack of connection were received by 20 (11%) patients and missed transmission by 22 (12%). The median time from notification to resolution was 2 days. After 3 months, 175 (99%) communicators of the 177 patients who installed the App were in "Monitored" status versus 113 (94%) of 120 patients without the App installed (p=0.033). The use of the app made 84% of patients feel reassured. CONCLUSIONS: The App was well accepted by CIED patients and offered support for communicator management and installation. Its use enabled patients to remain connected with greater continuity during follow-up.

The "Defibrillation Testing, Why Not?" survey. Testing of subcutaneous and transvenous defibrillators in the Italian clinical practice.

BACKGROUND: Defibrillation testing (DT) can be omitted in patients undergoing transvenous implantable cardioverter-defibrillator (T-ICD) implantation, but it is still recommended for patients at risk for a high defibrillation threshold and for ICD generator changes. Moreover, DT is still recommended on implantation of subcutaneous ICD (S-ICD). The aim of the present survey was to analyze the current practice of DT during T-ICD and S-ICD implantations. METHODS: In March 2021, an ad hoc questionnaire on the current performance of DT and the standard practice adopted during testing was completed at 72 Italian centers implanting S-ICD and T-ICD. RESULTS: 48 (67%) operators reported never performing DT during de-novo T-ICD implantations, while no operators perform it systematically. The remaining respondents perform it for patients at risk for a high defibrillation threshold. DT is never performed at T-ICD generator change. At the time of de-novo S-ICD implantation, DT is never performed by 9 (13%) operators and performed systematically by 48 (66%). The remaining operators frequently omit DT in patients with more severe systolic dysfunction. DT is not performed at S-ICD generator change by 92% of operators. DT is conducted by delivering a first shock energy of 65 J by 60% of operators, while the remaining 40% test lower energy values. CONCLUSIONS: In current clinical practice, most operators omit DT at T-ICD implantation, even when still recommended in the guidelines. DT is also frequently omitted at S-ICD implantation, and a wide variability exists among operators in the procedures followed during DT.

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.

Multiparametric Implantable Cardioverter-Defibrillator Algorithm for Heart Failure Risk Stratification and Management: An Analysis in Clinical Practice.

BACKGROUND: The HeartLogic algorithm combines multiple implantable cardioverter-defibrillator sensors to identify patients at risk of heart failure (HF) events. We sought to evaluate the risk stratification ability of this algorithm in clinical practice. We also analyzed the alert management strategies adopted in the study group and their association with the occurrence of HF events. METHODS: The HeartLogic feature was activated in 366 implantable cardioverter-defibrillator and cardiac resynchronization therapy implantable cardioverter-defibrillator patients at 22 centers. The median follow-up was 11 months [25th-75th percentile: 6-16]. The HeartLogic algorithm calculates a daily HF index and identifies periods IN alert state on the basis of a configurable threshold. RESULTS: The HeartLogic index crossed the threshold value 273 times (0.76 alerts/patient-year) in 150 patients. The time IN alert state was 11% of the total observation period. Patients experienced 36 HF hospitalizations, and 8 patients died of HF during the observation period. Thirty-five events were associated with the IN alert state (0.92 events/patient-year versus 0.03 events/patient-year in the OUT of alert state). The hazard ratio in the IN/OUT of alert state comparison was (hazard ratio, 24.53 [95% CI, 8.55-70.38], P<0.001), after adjustment for baseline clinical confounders. Alerts followed by clinical actions were associated with less HF events (hazard ratio, 0.37 [95% CI, 0.14-0.99], P=0.047). No differences in event rates were observed between in-office and remote alert management. CONCLUSIONS: This multiparametric algorithm identifies patients during periods of significantly increased risk of HF events. The rate of HF events seemed lower when clinical actions were undertaken in response to alerts. Extra in-office visits did not seem to be required to effectively manage HeartLogic alerts. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02275637.

Is 40 Joules Enough to Successfully Defibrillate With Subcutaneous Implantable Cardioverter-Defibrillators?

OBJECTIVES: This study evaluated the efficacy of conversion test performed at 40 J (defibrillation margin ≥40 J), and factors potentially associated with test failure were identified. BACKGROUND: Current subcutaneous implantable cardioverter-defibrillator (S-ICD) devices deliver a maximum of 80 J. Functional defibrillation testing is recommended at S-ICD implantation, and it is usually conducted by delivering a shock energy of 65 J to ensure a safety defibrillation margin ≥15 J. Although high rates of successful conversion were reported at 65 J, limited data exist on the defibrillation margin extent. METHODS: Ventricular fibrillation was induced and conversion test was performed by delivering a 40-J shock in 308 patients. Success was defined as termination of ventricular fibrillation by the first shock delivered in standard polarity. The S-ICD system positioning was evaluated with the PRAETORIAN score using bidirectional chest X-rays. RESULTS: The generator was positioned in an intermuscular pocket in 301 patients (98%) and the lead was implanted by means of a 2-incision technique. The PRAETORIAN score was <90 (low risk of conversion failure) in 293 (95%) patients. Overall, ventricular fibrillation termination occurred in 259 (84%) patients with 40 J. Male gender (odds ratio [OR]: 3.79; 95% confidence interval [CI]: 1.09 to 13.14; p = 0.036), body mass index (OR: 1.09; 95% CI: 1.01 to 1.19; p = 0.036), dilated cardiomyopathy with reduced ejection fraction (OR: 0.42; 95% CI: 0.20 to 0.87; p = 0.019), and PRAETORIAN score >50 (OR: 2.93; 95% CI: 1.26 to 6.83; p = 0.013) were independently associated with conversion failure. CONCLUSIONS: The authors showed a high rate of defibrillation success with 40-J shocks in S-ICD systems implanted by means of modern surgical techniques. The variables associated with shock failure were male gender, higher body mass index, and suboptimal device position according to the PRAETORIAN score.

Single- and multi-site pacing strategies for optimal cardiac resynchronization therapy: impact on device longevity and therapy cost.

BACKGROUND: Multiple left ventricular pacing strategies have been suggested for improving response to cardiac resynchronization therapy (CRT). However, these programming strategies may sometimes entail accepting configurations with high pacing threshold and accelerated battery drain. We assessed the feasibility of predefined pacing programming protocols, and we evaluated their impact on device longevity and their cost-impact. METHODS: We estimated battery longevity in 167 CRT-D patients based on measured pacing parameters according to multiple alternative programming strategies: single-site pacing associated with lowest threshold, non-apical location, longest interventricular delay, and pacing from two electrodes. To determine the economic impact of each programming strategy, we applied the results of a model-based cost analysis using a 15-year time horizon. RESULTS: Selecting the electrode with the lowest threshold resulted in a median device longevity of 11.5 years. Non-apical pacing and interventricular delay maximization were feasible in most patients and were obtained at the price of a few months of battery life. Device longevity of > 10 years was preserved in 87% of cases of non-apical pacing and in 77% on pacing at the longest interventricular delay. The mean reduction in battery life when the second electrode was activated was 1.5 years. Single-site pacing strategies increased the therapy cost by 4-6%, and multi-site pacing by 12-13%, in comparison with the lowest-cost scenario. CONCLUSIONS: Modern CRT-D systems ensure effective pacing and allow multiple optimization strategies for maximizing service life or for enhancing effectiveness. Single- or multi-site pacing strategies can be implemented without compromising device service life and at an acceptable increase in therapy cost.

Electrical synchronization achieved by multipoint pacing combined with dynamic atrioventricular delay.

PURPOSE: Multipoint pacing (MPP) improves left ventricular (LV) electrical synchrony in cardiac resynchronization therapy (CRT). SyncAV automatically adjusts atrioventricular delay (AVD) according to intrinsic AV intervals and may further improve synchrony. Their combination has not been assessed. The objective was to evaluate the improvement in electrical synchrony achieved by SyncAV combined with MPP in an international, multicenter study. METHODS: Patients with LBBB undergoing CRT implant with a quadripolar lead (Abbott Quartet™) were prospectively enrolled. QRS duration (QRSd) was measured by blinded observers from 12-lead ECG during: intrinsic conduction, BiV pacing (conventional biventricular pacing, nominal static AVD), MPP (2 LV cathodes maximally spaced, nominal static AVD), BiV + SyncAV, and MPP + SyncAV. All SyncAV offsets were individualized for each patient to yield the narrowest QRSd during BiV pacing. QRSd changes were compared by ANOVA and post hoc Tukey-Kramer tests. RESULTS: One hundred and three patients were enrolled (65.7 ± 12.1 years, 67% male, 37% ischemic, EF 26.4 ± 6.5%, PR 190.3 ± 39.1 ms). Relative to intrinsic conduction (QRSd of 165 ± 16 ms), BiV reduced QRSd by 11.9% to 145 ± 18 ms (P < 0.001 vs intrinsic), and MPP reduced QRSd by 13.3% to 142 ± 19 ms (P < 0.001 vs intrinsic). However, enabling SyncAV with a patient-optimized offset nearly doubled this QRSd reduction. BiV + SyncAV reduced QRSd by 22.0% to 128 ± 13 ms (P < 0.001 vs BiV), while MPP + SyncAV reduced QRSd further by 25.6% to 122 ± 14 ms (P < 0.05 vs BiV + SyncAV). CONCLUSION: SyncAV can significantly improve acute electrical synchrony beyond conventional CRT, with further improvement achieved by superimposing MPP.

Prospective evaluation of the multisensor HeartLogic algorithm for heart failure monitoring.

BACKGROUND: The HeartLogic algorithm measures data from multiple implantable cardioverter-defibrillator-based sensors and combines them into a single index. The associated alert has proved to be a sensitive and timely predictor of impending heart failure (HF) decompensation. HYPOTHESIS: We describe a multicenter experience of remote HF management by means of HeartLogic and appraise the value of an alert-based follow-up strategy. METHODS: The alert was activated in 104 patients. All patients were followed up according to a standardized protocol that included remote data reviews and patient phone contacts every month and at the time of alerts. In-office examinations were performed every 6 months or when deemed necessary. RESULTS: During a median follow-up of 13 (10-16) months, the overall number of HF hospitalizations was 16 (rate 0.15 hospitalizations/patient-year) and 100 alerts were reported in 53 patients. Sixty alerts were judged clinically meaningful, and were associated with multiple HF-related conditions. In 48 of the 60 alerts, the clinician was not previously aware of the condition. Of these 48 alerts, 43 triggered clinical actions. The rate of alerts judged nonclinically meaningful was 0.37/patient-year, and the rate of hospitalizations not associated with an alert was 0.05/patient-year. Centers performed remote follow-up assessments of 1113 scheduled monthly transmissions (10.3/patient-year) and 100 alerts (0.93/patient-year). Monthly remote data review allowed to detect 11 (1%) HF events requiring clinical actions (vs 43% actionable alerts, P < .001). CONCLUSIONS: HeartLogic allowed relevant HF-related clinical conditions to be identified remotely and enabled effective clinical actions to be taken; the rates of unexplained alerts and undetected HF events were low. An alert-based management strategy seemed more efficient than a scheduled monthly remote follow-up scheme.

ICD-measured heart sounds and their correlation with echocardiographic indexes of systolic and diastolic function.

BACKGROUND: Novel implantable defibrillators (ICDs) allow first (S1) and third (S3) heart sounds to be measured by means of an embedded accelerometer. ICD-measured S1 and S3 have been shown to significantly correlate with hemodynamic changes in acute animal models. The HeartLogic algorithm (Boston Scientific) measures and combines multiple parameters, including S3 and S1, into a single index to predict impending heart failure decompensation. We evaluated the echocardiographic correlates of ICD-measured S1 and S3 in patients with ICD and cardiac resynchronization therapy ICD. METHODS: The HeartLogic feature was activated in 104 patients. During in-office visits, patients underwent echocardiographic evaluation, and parameters of systolic and diastolic function were correlated with S3 and S1 amplitude measured on the same day as the visit. RESULTS: S3 amplitude inversely correlated with deceleration time of the E-wave (r = -0.32; 95% CI -0.46 - -0.17; P < 0.001), and S1 amplitude significantly correlated with left ventricular ejection fraction (r = 0.17; 95% CI 0.03-0.30; P = 0.021). S3 > 0.9 mG detected a restrictive filling pattern with 85% (95% CI 72%-93%) sensitivity and 82% (95% CI 75%-88%) specificity, while S1 < 1.5 mG detected ejection fraction < 35% with 28% (95% CI 19%-40%) sensitivity and 88% (95% CI 80%-93%) specificity. CONCLUSION: ICD-measured heart sound parameters are significantly correlated with echocardiographic indexes of systolic and diastolic function. This confirms their utility for remote patient monitoring when used as single sensors and their potential relevance when considered in combination with other physiological ICD sensors that evaluate various aspects of heart failure physiology.

Preliminary experience with the multisensor HeartLogic algorithm for heart failure monitoring: a retrospective case series report.

AIMS: In the Multisensor Chronic Evaluation in Ambulatory Heart Failure Patients study, a novel algorithm for heart failure (HF) monitoring was implemented. The HeartLogic (Boston Scientific) index combines data from multiple implantable cardioverter defibrillator (ICD)-based sensors and has proved to be a sensitive and timely predictor of impending HF decompensation. The remote monitoring of HF patients by means of HeartLogic has never been described in clinical practice. We report post-implantation data collected from sensors, the combined index, and their association with clinical events during follow-up in a group of patients who received a HeartLogic-enabled device in clinical practice. METHODS AND RESULTS: Patients with ICD and cardiac resynchronization therapy ICD were remotely monitored. In December 2017, the HeartLogic feature was activated on the remote monitoring platform, and multiple ICD-based sensor data collected since device implantation were made available: HeartLogic index, heart rate, heart sounds, thoracic impedance, respiration, and activity. Their association with clinical events was retrospectively analysed. Data from 58 patients were analysed. During a mean follow-up of 5 ± 3 months, the HeartLogic index crossed the threshold value (set by default to 16) 24 times (over 24 person-years, 0.99 alerts/patient-year) in 16 patients. HeartLogic alerts preceded five HF hospitalizations and five unplanned in-office visits for HF. Symptoms or signs of HF were also reported at the time of five scheduled visits. The median early warning time and the time spent in alert were longer in the case of hospitalizations than in the case of minor events of clinical deterioration of HF. HeartLogic contributing sensors detected changes in heart sound amplitude (increased third sound and decreased first sound) in all cases of alerts. Patients with HeartLogic alerts during the observation period had higher New York Heart Association class (P = 0.025) and lower ejection fraction (P = 0.016) at the time of activation. CONCLUSIONS: Our retrospective analysis indicates that the HeartLogic algorithm might be useful to detect gradual worsening of HF and to stratify risk of HF decompensation.

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.

Remote monitoring of subcutaneous implantable cardioverter defibrillators.

BACKGROUND: Remote monitoring (RM) of implantable cardioverter defibrillators (ICD) has been shown to improve patient safety and reduce in-office visits. The subcutaneous ICD (S-ICD) is an effective alternative to transvenous ICD and has recently been endowed with the RM function. However, the RM communicator for S-ICD requires patient interaction to activate data transmission. We assessed patient compliance and acceptance. METHODS: Patients with S-ICD received the communicator and were followed up for 15 months. Weekly remote transmissions were programmed. Compliance with checks was measured as the number of checks performed by the patient divided by the number of automatic notifications by the communicator. A questionnaire on acceptance of the system was administered to patients. RESULTS: A total of 106 patients were analyzed. The proportion of weekly checks properly executed by the patients was 94% during the first 3 months and 93% from months 12 to 15. Of the checks performed, 93% were on the same day as the automatic notification. On a patient basis, compliance with weekly checks was > 85% (less than one check missed per month) in 88% of patients during the first 3 months and in 82% from months 12 to 15 (p = 0.615). No variables emerged as predictors of lower (≤ 85%) long-term compliance with weekly checks. During follow-up, 49 alerts were transmitted and the mean delay between the detected event and the patient transmission was 2 ± 2 days. The majority of patients found the system easy to use and felt confident about being remotely monitored. CONCLUSIONS: The level of patient compliance with remote checks is high with current technology for RM of S-ICD. The vast majority of data transmissions are consistently performed on a weekly basis on the day scheduled.