Increasing Knowledge about Implantable Cardioverter Defibrillators at the End of Life, an Effective Approach for Hospice Workers to Improve Patient Care

BACKGROUND

Implantable cardioverter defibrillators (ICDs) decrease mortality in high-risk patients but can also cause distressing shocks near death. Patients who lack knowledge about their ICDs are more likely to have an active device at the end of life. Many hospice workers lack sufficient knowledge to educate patients about ICDs.

MEASURES

An ICD educational video created for use in a diverse, underserved patient population was shown to hospice workers from two large community hospices and attendees of a regional conference. A validated 10 question survey was given to participants before and after the video.

OUTCOMES

Significant improvement in ICD knowledge scores was seen in all participants (W = 3119.5, P < 0.0001). While doctors and nurses showed higher pretest knowledge, post-test knowledge scores equalized across all participants.

CONCLUSIONS/LESSONS LEARNED

An ICD patient educational video designed for a diverse, underserved patient population effectively improved ICD knowledge to a uniform excellent level for a broad range of hospice workers.

A comprehensive review on efficient artificial intelligence models for classification of abnormal cardiac rhythms using electrocardiograms

Deep learning has made many advances in data classification using electrocardiogram (ECG) waveforms. Over the past decade, data science research has focused on developing artificial intelligence (AI) based models that can analyze ECG waveforms to identify and classify abnormal cardiac rhythms accurately. However, the primary drawback of the current AI models is that most of these models are heavy, computationally intensive, and inefficient in terms of cost for real-time implementation. In this review, we first discuss the current state-of-the-art AI models utilized for ECG-based cardiac rhythm classification. Next, we present some of the upcoming modeling methodologies which have the potential to perform real-time implementation of AI-based heart rhythm diagnosis. These models hold significant promise in being lightweight and computationally efficient without compromising the accuracy. Contemporary models predominantly utilize 12-lead ECG for cardiac rhythm classification and cardiovascular status prediction, increasing the computational burden and making real-time implementation challenging. We also summarize research studies evaluating the potential of efficient data setups to reduce the number of ECG leads without affecting classification accuracy. Lastly, we present future perspectives on AI's utility in precision medicine by providing opportunities for accurate prediction and diagnostics of cardiovascular status in patients.

Development of the Implantable Cardioverter-Defibrillator: JACC Historical Breakthroughs in Perspective

Implantable cardioverter-defibrillators (ICDs) represent transformational technology, arguably the most significant advance in cardiovascular medicine in 50 years. The vision and determination of pioneers Mirowski and Mower was fundamental to this monumental achievement, working with limited resources and confronted by skepticism/criticism from medical establishment. The inventors were followed >35 years in which a multitude of innovative clinical scientists and engineers introduced technological advances leading to the sophisticated devices in practice today. A pivotal patient experiment with automated termination of ventricular fibrillation (1980) led to U.S. Food and Drug Administration approval. Transvenous lead systems converted ICDs from thoracotomy-based secondary prevention to primary prevention of sudden death devices in countless patients worldwide. ICD acceptance was solidified by prospective randomized controlled trials showing reduced mortality superior to antiarrhythmic drugs. ICDs eventually expanded from coronary disease to inherited arrhythmia conditions (eg, hypertrophic cardiomyopathy). The ICD breakthrough story demonstrates how significant progress is possible in medicine against all odds, given fearless imagination to pursue novel ideas that conflict with accepted wisdom.

Direct anchoring technique for pacing and defibrillation leads inserted through cephalic vein: insight for a single high-volume center

BACKGROUND

Direct anchoring of PM and ICD leads over cephalic vein body is officially discouraged by manufactures due to a supposed risk of conductor fracture or insulation failure, however careful tightening of anchoring knots can probably prevent lead damage. Direct anchoring (DA) technique is routinely used in our center for all leads inserted by cephalic vein while standard anchoring sleeves are used to secure subclavian leads only. Aim of the study is to assess short- and long-term safety of cephalic direct anchoring technique.

METHODS

All patients undergoing PM and ICD implantation in our center from November 2014 to March 2016 were consecutively enrolled. Primary endpoints were acute lead fracture, lead dislodgement and chronic lead failure. Secondary endpoint was a composite of short-term surgical complications (pocket hematoma, pneumothorax, and pericardial effusion) plus device infections. Subclavian leads secured with sleeve anchoring (SA) were used as control.

RESULTS

A total of 550 leads were implanted in 310 consecutive patients. DA involved 323 leads (59%) while SA was used for 227 (41%). Median follow-up was 50 months (IQR 24-62 months). 17 lead malfunctions (3.1%) were observed during follow-up. No difference was observed between groups (10 DA vs. 7 SP, P=ns). Survival analysis found no difference between groups. Secondary endpoints were not statistically different between groups (5 vs. 1, P=0.08).

CONCLUSIONS

Direct anchoring technique of PM and ICD leads is a safe technique and does not increase lead malfunction risk.

Implantable cardioverter defibrillators - the past, present and future

Since their formal introduction in 1980, implantable cardioverter defibrillators (ICDs) have undergone innumerable design modifications through several generations. They are indispensable today in successfully managing fatal ventricular arrhythmias. Their role in averting sudden cardiac death is recognized beyond doubt. Their applications and indications have continuously expanded over the last two decades. This article reviews the salient features in the evolution of ICDs, their current indications, recent advances and future directions. With more advanced detection algorithms, the potential integration with leadless pacing, and the possibility to serve as a remote monitoring device to recognize atrial fibrillation, acute ischemia, or electrolyte imbalance, the application of ICDs is rapidly evolving.

High shocking and pacing impedances due to defibrillation lead calcification

Purpose

We have reported the calcification of Endotak defibrillation leads that required replacement. The aim of this study was to assess calcified Endotak Reliance leads in the Food and Drug Administration Manufacturer and User Facility Device Experience (MAUDE) database and compare them to calcified Sprint Fidelis, Sprint Quattro Secure, Riata, and Durata leads in MAUDE.

Methods

We searched the MAUDE database from 2008 to 2019 for defibrillation lead calcification using the terms “calcium,” “calcification,” and “calcified”. Included were explanted leads whose manufacturers found calcium on the shocking and/or pacing electrode.

Results

The MAUDE search identified 113 calcified defibrillation leads that qualified for the study, including 109 Endotak Reliance leads, 1 Sprint Quattro Secure lead, 2 Durata leads, 1 Riata ST lead, and no Sprint Fidelis lead. The sign of calcification was a gradual increase in shocking or pacing impedance. Average implant time was 7.4 ± 3.1 (range: 1.3–16.5) years. Only Endotak Reliance leads had shocking coil calcification (n = 72; 66.0%) and five (6.9%) of these failed defibrillation threshold (DFT) testing. Distal pacing electrode calcification affected 55 (50.4%) Endotak Reliance leads. The four other leads had pacing ring electrode calcification only.

Conclusion

Endotak Reliance defibrillation leads appear prone to shocking coil and/or distal pacing electrode calcification. High impedances may compromise defibrillation and pacing therapy. Patients who have these leads should be monitored; those exhibiting high shocking impedances should be considered for DFT testing. Lead replacement should be considered for pacemaker-dependent patients whose leads exhibit progressively high impedances.

Analysis of early failure of Biotronik Linox Smart implantable cardioverter-defibrillator leads: A comparative study of three defibrillator leads

BACKGROUND AND OBJECTIVES

Early failure of Biotronik Linox and Linox Smart leads (Biotronik, Berlin, Germany) has been reported in numerous recent publications. The aim of this study was to assess the performance of this lead compared with that of two other contemporary leads.

METHODS

We conducted an ambispective study of all consecutive first implantations of defibrillator leads carried out in our center: Endotak (model 148, 158, Boston Scientific, Marlborough, MA, USA) (n = 173), Sprint Quattro (model 6644, 6947, Medtronic, Dublin, Ireland) (n = 145), and Linox Smart (Biotronik, model SD 65/16) (n = 120).

RESULTS

During a median follow-up of 4.6 ± 2.1 years, failure occurred in nine Linox Smart (7.5%), one Endotak Reliance (0.6%), and no Sprint Quattro leads. The survival probability of the Linox Smart group was significantly lower than that of the Endotak and Sprint Quattro groups measured by the log-rank test (Linox vs Endotak; P < 0.001 and Linox vs Sprint Quattro; P < 0.001). Nonphysiological signals not due to external interference were observed in all Linox Smart leads, with normal parameters and without visible anomalies on chest x-ray.

CONCLUSIONS

In this single-center experience, the survival rate of Linox Smart leads was 88% at 5 years of follow-up, which was significantly lower than that of the other leads. Comprehensive vigilance of Linox Smart leads, including home monitoring, may be advisable to facilitate early detection of lead failure and avoid inappropriate shocks.

Comparative study of the failure rates among 3 implantable defibrillator leads

BACKGROUND

After the introduction of the Biotronik Linox S/SD high-voltage lead, several cases of early failure have been observed.

OBJECTIVE

The purpose of this article was to assess the performance of the Linox S/SD lead in comparison to 2 other contemporary leads.

METHODS

We used the prospective Erasmus MC ICD registry to identify all implanted Linox S/SD (n = 408), Durata (St. Jude Medical, model 7122) (n = 340), and Endotak Reliance (Boston Scientific, models 0155, 0138, and 0158) (n = 343) leads. Lead failure was defined by low- or high-voltage impedance, failure to capture, sense or defibrillate, or the presence of nonphysiological signals not due to external interference.

RESULTS

During a median follow-up of 5.1 years, 24 Linox (5.9%), 5 Endotak (1.5%), and 5 Durata (1.5%) leads failed. At 5-year follow-up, the cumulative failure rate of Linox leads (6.4%) was higher than that of Endotak (0.4%; P < .0001) and Durata (2.0%; P = .003) leads. The incidence rate was higher in Linox leads (1.3 per 100 patient-years) than in Endotak and Durata leads (0.2 and 0.3 per 100 patient-years, respectively; P < .001). A log-log analysis of the cumulative hazard for Linox leads functioning at 3-year follow-up revealed a stable failure rate of 3% per year. The majority of failures consisted of noise (62.5%) and abnormal impedance (33.3%).

CONCLUSION

This study demonstrates a higher failure rate of Linox S/SD high-voltage leads compared to contemporary leads. Although the mechanism of lead failure is unclear, the majority presents with abnormal electrical parameters. Comprehensive monitoring of Linox S/SD high-voltage leads includes remote monitoring to facilitate early detection of lead failure.

[ICD leads]

Implantable cardioverter-defibrillator (ICD) leads have to fulfill particular requirements: safe pacing and sensing, detection, and termination of ventricular tachyarrhythmias, if necessary by (multiple) high-energy shocks. At the same time, their implantation has to be simple, they need to provide excellent long-term stability and they must be completely and safely extractable. Numerous technical developments have enabled currently available ICD leads to fulfill these expectations to a high extent. However, some changes of lead design, materials, and manufacturing processes have led to increased lead failure, especially in two lead models (Medtronic Sprint Fidelis®, St. Jude Medical Riata®). The high rate of lead failure was identified only several years after market release, in part because there are no appropriate registries of ICD leads. This review presents background and developments of ICD lead technology and their association with the clinical usage of ICD therapy. To also benefit patients with only slightly-to-moderately increased risk of ventricular tachyarrhythmia, optimum ICD therapy requires optimal leads and sufficiently experienced implanters.