Cardiac Electronic Devices: Future Directions and Challenges

Figures & data

Table 1 Comparison of Implantable Cardioverter Defibrillators

	Transvenous ICD	Subcutaneous ICD	Substernal Lead
Intracardiac lead	+	–	–
Ventricular pacing	+	–	+
Antitachycardia pacing	+	–	+
Defibrillation efficacy	+	+	+
Shock energy	40 J	80 J	40 J
Implantation procedure	Feasible	Feasible	Feasible
Periprocedural complication rates	4%	4%	Unknown
Risk of infection	8.9/1,000 device-years	Low	Unknown

Note: Data from references 56, 57, 59, 61, and 113.

Abbreviation: ICD, implantable cardioverter defibrillator.

Table 2 Expected Advantages of Remote Monitoring of Cardiac Electronic Implantable Devices

Selection of patients who require urgent medical intervention

Key information about the function of the device

Reduction of in-person visits

Patient has an active role in therapeutic process

Economic issues: decreased use of health-care resources and cost savings

Essential part of the integrated medical care of patients with heart failure and arrhythmias

Safe, easy, and feasible method

Table 3 Remote Monitoring of Patients with Cardiac Resynchronization Therapy

Most Common “Unscheduled” Alerts	Most Common Medical Interventions	Medical Interventions
CRT pacing <95% (63%)	Any medical intervention (63.9%)	None — 36.1%
VT/VF episodes (24.9%)	Device reprogramming (46.8%)	One — 38.4%
AF de novo (15.7%)	Qualification for any ablation (12.6%)	≥Two or more — 25.5%

Notes: Data from Liberskaet al.64

Abbreviations: CRT, cardiac resynchronization therapy; VT, ventricular tachycardia; VF, ventricular fibrillation; AF, atrial fibrillation.

Table 4 Atrial High–rhythm Episodes: Common Causes of Atrial Fibrillation Misdetections,

Atrial undersensing

Ventricular far-field oversensing

Atrial noise: external interference/lead dislocation/lead fracture

Ineffective atrial pacing

Notes: Data from Jȩdrzejczyk-Patej et al67 and Gorenek et al.68

Table 5 Studies of Remote Monitoring of Cardiac Electronic Implantable Devices

	Type	Design	Follow-Up	Results	Findings
Hindricks et al^Citation91	RCT	n=716 patients with HF and ICD/CRT Telemonitoring group (n=333) vs control group (n=331)	12 months	Worsened composite clinical score: 18.9% vs 27.2%, OR 0.63 (95% CI 0.43–0.90) Death: 3.0% vs 8.2%	Telemonitoring improves clinical outcomes for HF patients
Sardu et al^Citation92	RCT	n=191 patients with HF and CRT Telemonitoring group (n=89) vs control group (n=94)	12 months	HF hospitalization: 15.7% vs 28.7% HR 0.6 (95% CI 0.42–0.79)	Telemonitoring may predict HF hospitalization
Morgan et al^Citation94	RCT	n=1,650 patients with HF and ICD/CRT Telemonitoring group (n= 824) vs control group (n=826)	24–42 months	Primary end point (first death from any cause or unplanned hospitalization for cardiovascular reasons): 42.4 vs 40.8%, HR 1.01 (95% CI 0.87–1.18)	Telemonitoring does not improve outcomes for HF patients
Boriani et al^Citation93	RCT	n= 865 patients with HF and CRT Telemonitoring group (n= 437) vs control group (n=428)	24 months	Primary end point (composite of death and cardiovascular and device-related hospitalization): 29.7% vs 28.7%, HR 1.02 (95% CI 0.80–1.30) 41% reduction in in-person visits in telemonitoring group	Telemonitoring does not improve outcomes for HF patients Better use of health-care resources and cost savings
Tajstra et al^Citation95	RCT	n=600 patients with HF and ICD/CRT Telemonitoring group (n=299) vs control group (n=301)	12 months	Primary end point (composite of all-cause death and cardiovascular-related hospitalization): 39.5% vs 48.5% OR 1.24 (95% CI 1.0–1.5)	Telemonitoring improves clinical outcomes for HF patients

Abbreviations: RCT, randomized controlled trial; HF, heart failure; ICD, implantable cardioverter defibrillator; CRT, cardiac resynchronization therapy.

Table 6 Wearable Technologies – an Insight from Observational Studies

	Apple Heart Study^Citation106,Citation107	Huawei Heart Study^Citation108
Type	Prospective cohort	Prospective cohort
Patients	n=419,297	n=187,912
Design	Individuals without AF monitored for irregular rhythm Possible AF, confirmed on ECG	Individuals monitored for pulse rhythm Possible AF, confirmed by clinical evaluation
Technology	Apple Watch	Wristband (Honor Band 4) or wristwatch (Huawei Watch GT, Honor Watch)
Follow-up	8 months	7 months
Results	2,161 participants (0.52%) received notifications of irregular pulse 34% of those were truly AF PPV: 84 (95% CI 76–92)	424 participants (0.23%) received a “suspected AF” notification 87% of those were truly AF PPV: 91.6 (95% CI 91.5–91.8)

Notes: Data fromTurakhia et al [2019]106, Perez et al [2019]107, Guo et al [2020].108

Abbreviations: ECG, electrocardiography; AF, atrial fibrillation; PPV, positive predictive value.

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