Rationale and design of the Lead Evaluation for Defibrillation and Reliability study: Safety and efficacy of a novel ICD lead design

BACKGROUND

Implantable cardioverter defibrillators (ICD) are indicated for primary and secondary prevention of sudden cardiac arrest. Despite enhancements in design and technologies, the ICD lead is the most vulnerable component of the ICD system and failure of ICD leads remains a significant clinical problem. A novel, small-diameter, lumenless, catheter-delivered, defibrillator lead was developed with the aim to improve long-term reliability.

METHODS AND RESULTS

The Lead Evaluation for Defibrillation and Reliability (LEADR) study is a multi-center, single-arm, Bayesian, adaptive design, pre-market interventional pivotal clinical study. Up to 60 study sites from around the world will participate in the study. Patients indicated for a de novo ICD will undergo defibrillation testing at implantation and clinical assessments at baseline, implant, pre-hospital discharge, 3 months, 6 months, and every 6 months thereafter until official study closure. Patients may be participating for a minimum of 18 months to approximately 3 years. Fracture-free survival will be evaluated using a Bayesian statistical method that incorporates both virtual patient data (combination of bench testing to failure with in-vivo use condition data) with clinical patients. The clinical subject sample size will be determined using decision rules for number of subject enrollments and follow-up time based upon the observed number of fractures at certain time points in the study. The adaptive study design will therefore result in a minimum of 500 and a maximum of 900 patients enrolled.

CONCLUSION

The LEADR Clinical Study was designed to efficiently provide evidence for short- and long-term safety and efficacy of a novel lead design using Bayesian methods including a novel virtual patient approach.

Performance of first pacemaker to use smart device app for remote monitoring

Background

High adherence to remote monitoring (RM) in pacemaker (PM) patients improves outcomes; however, adherence remains suboptimal. Bluetooth low-energy (BLE) technology in newer-generation PMs enables communication directly with patient-owned smart devices using an app without a bedside console.

Objective

To evaluate the success rate of scheduled RM transmissions using the app compared to other RM methods.

Methods

The BlueSync Field Evaluation was a prospective, international cohort evaluation, measuring the success rate of scheduled RM transmissions using a BLE PM or cardiac resynchronization therapy PM coupled with the MyCareLink Heart app. App transmission success was compared to 3 historical “control” groups from the Medtronic de-identified CareLink database: (1) PM patients with manual communication using a wand with a bedside console (PM manual transmission), (2) PM patients with wireless automatic communication with the bedside console (PM wireless); (3) defibrillator patients with similar automatic communication (defibrillator wireless).

Results

Among 245 patients enrolled (age 64.8±15.6 years, 58.4% men), 953 transmissions were scheduled through 12 months, of which 902 (94.6%) were successfully completed. In comparison, transmission success rates were 56.3% for PM manual transmission patients, 77.0% for PM wireless patients, and 87.1% for defibrillator wireless patients. Transmission success with the app was superior across matched cohorts based on age, sex, and device type (single vs dual vs triple chamber).

Conclusion

The success rate of scheduled RM transmissions was higher among patients using the smart device app compared to patients using traditional RM using bedside consoles. This novel technology may improve patient engagement and adherence to RM.

P577Early experience with the first pacemakers to directly connect with smart devices for remote monitoring

Background

Remote monitoring is associated with improved patient outcomes; however, adoption and adherence to remote monitoring via home-based consoles remains suboptimal. BlueSync technology in new generation pacemaker and CRT-P models enables the implanted device to communicate directly with patient-owned, Bluetooth-equipped smartphones/tablets and an app (MyCareLink Heart). The app can automatically retrieve information from the cardiac device and transmit the data to the remote network, eliminating the need for traditional remote monitoring consoles.

Objectives

To characterize the communication process between implanted pacemakers and smart device remote monitoring apps by assessing the success of prescheduled remote transmissions in the first month of follow-up. Additionally, to assess the feedback of both patients and clinicians about the process of device pairing.

Methods

Enrollment in the BlueSync Field Evaluation began in April 2018 and was completed November 2018. Follow-up is ongoing. Prior to enrollment in the evaluation, patients completed the device pairing process with the app using their own compatible smartphone or tablet. Patient and clinician questionnaires were completed at the time of the device pairing process. After enrollment, successful completion of scheduled transmissions occurring in the first month were analyzed.

Results

Preliminary data includes 241 enrolled patients with mean age of 64.7±15.5 yrs (min 20, max 90 yrs), who completed device pairing between their implanted device and their smart device app. Of enrolled patients, 79% felt that the device paring was easy to do, 85% were satisfied with the amount of time it took to complete it, and 93% felt that they would be comfortable using the app. Clinicians reported that 67% of the device pairings took less than 20 minutes and 78% felt patients would be able to use the app independently. At the time of analysis 174 patients had at least one scheduled transmission within the first month, and collectively had a total of 322 scheduled transmissions. Out of these, 309 (96%, 95% CI: 93%-98%) were successfully completed.

MyCareLink Heart App

Conclusions

Initial experience with the world's first app based remote monitoring system for Bluetooth enabled pacemakers demonstrated success to scheduled transmissions in the first month across a wide range of patient ages. Patients and clinicians reported high satisfaction with this novel technology.

Acknowledgement/Funding

Medtronic PLC

Design of the Primary Prevention Parameters Evaluation (PREPARE) trial of implantable cardioverter defibrillators to reduce patient morbidity [NCT00279279]

BACKGROUND

Implantable Cardioverter Defibrillator (ICD) therapy has been proven to be beneficial and efficacious for the treatment of serious ventricular tachyarrhythmias in primary prevention patients. However, primary prevention patients appear to have a lower incidence of ventricular arrhythmias in comparison to secondary prevention patients and consequently likely experience a higher proportion of detections due to supraventricular arrhythmias. Recent trials have demonstrated that strategic and specific programming choices reduce the number of inappropriate shocks and that anti-tachycardia pacing (ATP) is an effective alternative to shock therapy for many sustained ventricular arrhythmias.

METHODS

The Primary Prevention Parameters Evaluation (PREPARE) study is a multi-center cohort study, evaluating the efficacy of a pre-specified strategic profile of VT/VF detection and therapy settings in 700 primary prevention patients in an effort to safely reduce the number of shock therapies delivered. The patients, both with and without cardiac resynchronization therapy, are compared to a well-qualified set (n = 691) of historical controls derived from the MIRACLE ICD and EMPIRIC trials. This manuscript describes the design of the PREPARE study. The study results, to be presented separately, will characterize the efficacy of this programming set (PREPARE) compared with physician-tailored programming (MIRACLE ICD and EMPIRIC).

Detection and management of an implantable cardioverter defibrillator lead failure: incidence and clinical implications

OBJECTIVES

This study evaluated the long-term reliability of an implantable cardioverter defibrillator (ICD) lead to determine the incidence, clinical presentation, and management of lead failure.

BACKGROUND

Despite recent advances in ICD technology, the long-term reliability of ICD leads remains a significant problem.

METHODS

Concern about long-term reliability of coaxial polyurethane ICD leads caused us to systematically study all patients implanted with Medtronic (Minneapolis, Minnesota) 6936 lead at our institution. We performed follow-up of 74 patients with 76 ICD leads that were implanted from February 28, 1995 to September 8, 1997. Thirty-seven patients underwent routine clinical ICD follow-up testing and ventricular fibrillation induction to determine the status of their ICD lead after a mean follow-up of 68.6 +/- 8.2 months.

RESULTS

The lead survival analysis shows a cumulative failure probability of 37% (confidence interval, 24% to 54%) at 68.6 months. Six patients demonstrated a previously undescribed mode of ICD lead failure: prolonged oversensing immediately after shock therapy. The use of short interval counters to monitor nonphysiologic R-R intervals and the measurement of ring-to-coil impedance detected early lead failures in five patients.

CONCLUSIONS

This analysis shows: 1) problems with ICD leads may not become apparent until late during follow-up and may become a significant late problem, 2) a "signature" mode of lead failure for the 6936 consisting of oversensing of electrical noise following shocks, 3) early detection of lead failure with a short interval counter algorithm or measurement of ring-to-coil impedance may be clinically useful.

Using ratios to measure hospital financial performance: can the process be simplified?

Evaluation of a hospital's financial condition is often contingent upon the analysis of financial ratios. This study of 114 Illinois hospitals sought to simplify the financial assessment process by exploring the empirical dimensions that underlie 25 financial ratios. Results of a factor analytic solution suggest that there are five underlying factors which account for approximately 77% of the total variance. Uses of summative scaled measures in health services financial management and research are discussed.

An analytical review of hospital financial performance measures

Hospital administrators must have timely, valid, and interpretable financial information that allows them to make operational decisions in response to the threats of the changing health care environment. Aggregate indexes that reflect dimensions of hospital financial performance and simplify the information in financial ratios are needed to aid in decision making. This article reviews the development and use of hospital financial performance measures and lays the groundwork for research into deriving a multidimensional measure.