Icd primary prevention trials

This review will summarize the rationale for S-ICDs in the appropriate patient population, in the context of the most relevant literature.

A significant limitation of conventional ICDs is the implantation of transvenous leads, which lend themselves to a variety of potential complications. Such shocks can also occur as a result of myopotentials and T wave oversensing. This eliminates many of the potential risks previously outlined. Furthermore, fluoroscopy is not required during the procedure because insertion of the S-ICD system is guided by anatomical landmarks only.

The structure of S-ICD leads also allows for enhanced durability in comparison with transvenous leads. S-ICD leads do not require a stylet for placement and have no central lumen, which allows for higher tensile strength. However, it is important note that S-ICD infections are not associated with endocarditis and bacteremia. In a study by Bardy et al. They reported pocket infections in two of 55 patients enrolled in the European clinical trial. Among the patients in the IDE trial, 18 5.

Four of these infections required explant, and the remaining 14 were considered superficial or incisional infections 4. Reported infection rates have varied considerably between retrospective analyses. There were higher rates noted in studies by Jarman et al. Venous access is not used for S-ICD implantation but site complications such as hematoma and device erosion can still occur, although they are rare.

With regard to the risk of device erosion, large pulse generator size and implant location have been problematic. The highest rates of device erosion have been reported by Jaman et al. Trials have reported high success rates for tachyarrhythmia detection and shock efficacy for S-ICDs. Bardy et al. S-ICD shocks for spontaneous arrhythmias are non-programmable at 80J, but reverse polarity with successive shocks if additional shocks are required for successful defibrillation.

In their retrospective analysis, Do et al. This was further supported in the study by Francia et al. Posterior generator and coil positioning have been associated with lower DFTs. High impedance is also associated with inadequate coil depth and lower rate of defibrillator success. Inappropriate shocks as a result of oversensing or errors in arrhythmia discrimination had been one of the main drawbacks of S-ICDs with early generations of the device and programming.

Jarman et al. However, not all studies describe rates that high. Rates of 2. High shock rates in early S-ICD trials were often a result of T wave oversensing, lead migration, or supraventricular tachycardias SVTs at rates in the shock zone where discrimination algorithms are inactive.

However, the use of a conditional zone, where discriminators are active, in addition to a higher rate shock zone, improved discrimination. The importance of the conditional zone for discrimination was apparent in analyses of prospective trials and is now the standard programming used. This study demonstrated a complication free rate of Figure 1 shows the comparison of annual inappropriate shock rates between some of the major trials.

Annual Inappropriate Shock Rate Comparison. One of the major limitations of S-ICDs is the lack of pacemaker capability.

Unfortunately, this limits its use in the advanced heart failure population, as QRS prolongation, which may benefit from CRT, is an important component of therapy for this cohort. According to data from the European Regulatory Trial cohort, one of 55 patients 1. Such ATP is not available in the S-ICD, but explant of the device for this indication is uncommon, probably because of exclusion of patients with known monomorphic VT at rates likely to be pace terminated.

This confirms that proper patient selection can minimize the need for subsequent device upgrade for pacing. This was initially performed manually and could be time consuming. The quality of the long-term adverse events suffered from a lack of harmonized definitions and systematic ascertainment.

Future research is needed to address comparative effectiveness for quality of life and other patient reported outcomes and to explore treatment heterogeneity according to baseline risk. Consistent reporting of rates of SCD in the non-ICD trial arms would facilitate an assessment of how the mortality benefit may be correlated with the baseline risk. Conclusions: There is a high strength of evidence that ICD therapy for primary prevention of SCD, versus no ICD therapy, shows benefit with regard to all cause mortality and SCD in patients with reduced left ventricular ejection fraction and ischemic or nonischemic cardiomyopathy beyond the immediate post-MI or coronary revascularization periods.

Studies failed to show statistically significant differences for all-cause mortality across subgroups. Excerpt Background: Implantable cardioverter—defibrillators ICDs are battery-powered implantable devices that monitor heart rhythm and deliver therapy in the form of either electric shock or antitachycardia pacing ATP when a life-threatening ventricular arrhythmia is detected. Publication types Review.

A common scenario occurs with interference from electrocautery during surgical procedures. Advice from the heart rhythm specialist team may be required to avoid the consequences of such interactions.

Many times the placement of a magnet on the ICD generator, essentially inactivating the ICD portion of the device, while continuously monitoring the patient is all that is required to safely perform such procedures on patients. Patients with ICDs have an underlying cardiac condition in most if not all cases. Both CHF and CAD are progressive disease processes that require lifelong follow-up and require chronic medications for maintenance. Adherence to follow-up guidelines for ICDs may avoid complications.

Such evaluations include evaluation and prevention of inappropriate shock, management of recurrent arrhythmias, and regular follow-up for device function and battery status. The importance of medical compliance for the patients underlying cardiac condition is paramount in reducing hospitalization. In the case of ICDs, education in ICD management for surgical procedures will minimize device interference with other medical procedures.

N Engl J Med. Aggarwal, Wang. Heart Rhythm. DRG Cardiac defibrillator placement without cardiac catheterization. Anticipated length of stay for ICD placement is less than 24 hours for patients with observational status. In patients with more comorbidity or complexity, inpatient hospitalization may be required for anticoagulation management, heart failure management, or further invasive testing.

All rights reserved. No sponsor or advertiser has participated in, approved or paid for the content provided by Decision Support in Medicine LLC. Show More. Login Register. Read an unlimited amount by logging in or registering at no cost. Implantable Cardioverter-Defibrillators: What every physician should know. Continue Reading. Jump to Section I. Does your patient have or need an ICD? History Part 2: Prevalence: C. History Part 3: Competing diagnoses that can mimic dangerous Ventricular Arrhythmias.

Physical Examination Findings. What diagnostic tests should be performed? What laboratory studies if any should be ordered to help establish the diagnosis? How should the results be interpreted? What imaging studies if any should be ordered to help establish the diagnosis? Immediate management. Multicenter Automatic Defibrillator Implantation Trial investigators. N Engl J Med ; : — A randomized study of the prevention of sudden death in patients with coronary artery disease.

Multicenter Unsustained Tachycardia Trial investigators. Prophylactic implantation of a defibrillator in patients with myocardial infarction and reduced ejection fraction.

Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure. Implantable defibrillators for the prevention of mortality in patients with nonischemic cardiomyopathy: a meta-analysis of randomized controlled trials. JAMA ; : — 9. Defibrillator Implantation in patients with nonischemic systolic Heart failure. BMJ ; : b Syst Rev ; 1 : 2. Canadian implantable defibrillator study CIDS : a randomized trial of the implantable cardioverter defibrillator against amiodarone.

Circulation ; : — A comparison of antiarrhythmic-drug therapy with implantable defibrillators in patients resuscitated from near-fatal ventricular arrhythmias. Randomized comparison of antiarrhythmic drug therapy with implantable defibrillators in patients resuscitated from cardiac arrest : the Cardiac Arrest Study Hamburg CASH.

Cardiac-resynchronization therapy with or without an implantable defibrillator in advanced chronic heart failure. Cardiac-resynchronization therapy for mild-to-moderate heart failure. The effect of cardiac resynchronization on morbidity and mortality in heart failure. Cardiac-resynchronization therapy for the prevention of heart-failure events.

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Circulation ; : — 8. Amiodarone versus implantable cardioverter-defibrillator: randomized trial in patients with nonischemic dilated cardiomyopathy and asymptomatic nonsustained ventricular tachycardia--AMIOVIRT. J Am Coll Cardiol ; 41 : — Prophylactic defibrillator implantation in patients with nonischemic dilated cardiomyopathy. N Engl J Med ; : — 8. The cost-effectiveness of primary prophylactic implantable defibrillator therapy in patients with ischaemic or non-ischaemic heart disease: a European analysis.

Eur Heart J ; 34 : — 9. Implantable cardioverter-defibrillator for nonischemic cardiomyopathy: an updated meta-analysis. Circulation ; : — 3. Cause of death in clinical research: time for a reassessment? J Am Coll Cardiol ; 34 : — Footnotes Contributors AFB conceived the idea, performed data extraction and drafted the manuscript.