ICD Efficacy Should Be Evaluated at Implantation

Markowitz, Steven M.

doi:10.1016/j.ccep.2011.08.002

Cited by 3 publications

(5 citation statements)

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“…Complications associated with DSM testing are rare, but there is increasing controversy over whether the risks of testing are justifiable, especially in primary prevention patients, many of whom may have no other episodes of VF. 1,[19][20][21][22][23] However, a combination of anatomic and physiological factors still contributes to a small percentage of patients being inadequately protected at the time of implant. 1 No reliable method has been established for identifying these patients in advance, and there are no current guidelines for when ICD testing may be avoided ULV-based testing methods have the potential to significantly reduce VF inductions at ICD implantation testing, while providing adequate sensitivity to detect patients requiring system revision.…”

Section: Discussionmentioning

confidence: 99%

Automated Vulnerability Testing Identifies Patients With Inadequate Defibrillation Safety Margin

Birgersdotter‐Green

Ruetz

Anand

et al. 2012

Circ: Arrhythmia and Electrophysiology

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Background-Implantable cardioverter-defibrillator system efficacy is tested at implant by induction of ventricular fibrillation (VF). Defibrillation safety margin can be assessed without VF induction using upper limit of vulnerability methods, but these methods have required manual determination of T-wave timing. Methods and Results-To test the feasibility of an inductionless system of implant testing, a multicenter prospective study of an automated vulnerability safety margin system was conducted, which measured T-wave timing using an intracardiac electrogram during a ventricular pacing train. The system delivered up to 4 T-wave shocks of 18 J. Lack of VF induction by all 4 shocks was considered evidence of defibrillation adequacy. Patients subsequently underwent conventional defibrillation testing to meet a standard implant criterion. The 95% lower CI for defibrillation success at 25 J for noninduced patients was found using Bayesian statistics. Sixty patients were enrolled at 6 centers. Vulnerability testing and defibrillation success results were obtained from 54 patients. Vulnerability testing induced VF in 10 (19%) patients, of whom 2 required system revision. All patients not induced by vulnerability testing were successfully defibrillated twice at ≤25 J. The Bayesian credible interval was 97% to 100% for the population success rate of defibrillation at 25 J for automated vulnerability safety margin noninduced patients. Conclusions-An automated system identified all patients who failed conventional safety margin testing, while inducing only 19% of patients. Although limited by sample size, this study suggests the feasibility of automated implant testing that substantially reduces the need for VF induction in patients receiving implantable cardioverter-defibrillators. (Circ Arrhythm Electrophysiol. 2012;5:1073-1080.)

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Section: Discussionmentioning

confidence: 99%

Automated Vulnerability Testing Identifies Patients With Inadequate Defibrillation Safety Margin

Birgersdotter‐Green

Ruetz

Anand

et al. 2012

Circ: Arrhythmia and Electrophysiology

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“…The prevailing rationale for intraoperative ICD testing has been to identify DFT as basis for programming ICD shock parameters and to ensure appropriate detection of ventricular fibrillation/tachyarrhythmia, system integrity, and effective termination of arrhythmia. [4][5][6] DFT test represents repeated induction of ventricular fibrillation and subsequent application of testshocks with decreasing energy afterward to determine the threshold for effective defibrillation. In the last decade, a shift from DFT toward an intraoperative DT happened to reduce number of defibrillations and possible complications.…”

Section: Introductionmentioning

confidence: 99%

Intraoperative Defibrillation Testing Should Not Be Generally Abandoned for All ICD Procedures—A Multicenter Study on 4,572 Consecutive Patients

Ziegelhoeffer

Siebel

Markewitz

et al. 2016

Thorac cardiovasc Surg

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The ongoing technical advances in development of new implantable cardioverter defibrillator (ICD) systems led some investigators to question the routine use of intraoperative defibrillation testing (DT). Therefore, we evaluated retrospectively in a multicenter study effectiveness, safety, and usefulness of intraoperative DT on unbiased large patient population. Data from 4,572 consecutive patients undergoing any ICD intervention were retrospectively analyzed. Besides efficacy of DT, risk factors for DT failure were identified in a multiple logistic regression analysis. Overall 5,483 shock data from 4,532 patients were available. Not tested for medical reasons were 13.5%. DT-associated complications were not noted. Primary DT effectiveness was 95.8%, whereas 4.2% were ineffective. Optimization (51.6% increase of DT energy, 10.1% subcutaneous lead array (SQ array), 2% generator exchange, 4.8% lead reposition, 9.3% lead exchange, and 22.2% change of shock parameters) led to successful DT in 152 patients (96.2%). Subanalyses and logistic regression identified implantation of generator in any other position than left subpectoral, age, body mass index and left ventricular ejection fraction as independent predictors for primary DT failure. The number of patients, including those undergoing generator exchange, system upgrade, or system revision, with inappropriate intraoperative testshock is relatively high. The results of recent prospective clinical trials can be extrapolated only on first ICD implantations with high-energy generators. For patients undergoing subcutaneous ICD implantation, right-sided implantation, patients with channelopathies and hypertrophic cardiomyopathy, as well as for procedures on already implanted ICD systems, the intraoperative DT might still be recommended.

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“…The arguments and evidence against the determination of the DFTs include the risks of major complications related to the testing (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18). Death, stroke, myocardial infarction, and anesthesia-related complications related to DFT determination are reported in Ͻ1% of implants.…”

mentioning

confidence: 98%

“…Multiple arguments and lines of evidence support the routine evaluation of DFTs at ICD insertion (1)(2)(3). The prospective randomized trials demonstrating efficacy of the ICD for primary and secondary prevention of sudden death have required DFT testing.…”

mentioning

confidence: 99%

“…The prospective randomized trials demonstrating efficacy of the ICD for primary and secondary prevention of sudden death have required DFT testing. Evaluation of DFTs allows verification of sensing, integrity of the high-voltage system, and programming lower initial shock energy for ventricular fibrillation at 10 J over the DFT (1)(2)(3). Testing of defibrillation efficacy represent a historical standard of care, and eliminating the DFT testing may present a medical legal issue for the physician performing the implantation (1)(2)(3).…”

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confidence: 99%

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Defibrillation Testing

Estes

2012

Journal of the American College of Cardiology

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In 3 decades of clinical use of the implantable cardioverterdefibrillator (ICD), defibrillation threshold (DFT) testing has remained an integral part of the implantation procedure. The prevailing rationale for the routine evaluation of DFTs has been to ensure appropriate sensing of ventricular fibrillation, system integrity, and effective defibrillation (1-3). Early ICD systems using monophasic waveforms with epicardial patches or transvenous leads were associated with a substantial incidence of elevated DFTs, requiring additional intervention to ensure clinical efficacy (1-3). Technically, the DFT is a probabilistic phenomenon requiring multiple shocks to determine with precision. Clinically, the DFT is commonly approximated with 1 or more shocks to See page 981 terminate induced ventricular fibrillation and ensure a safety margin between the DFT and the maximum output of the ICD. Inadequate safety margins of Ͻ10 J between the DFT and maximum ICD energy delivery have been associated with worse clinical outcomes (3). Contemporary ICD systems using active cans, pectoralis pulse generators, biphasic waveforms, and intravascular high-voltage leads have considerably lowered the incidence of elevated DFTs (4 -13). The reliability of current ICD systems has led implanting physicians to abandon the practice of routine testing of defibrillation efficacy before hospital discharge and annually. Observational studies also have noted an elimination of DFT testing in one-third of initial implants and two-thirds of replacements (14 -16). Indeed, based on a growing body of evidence, the clinical utility of the determination of defibrillation efficacy during de novo implants has been questioned (4 -13). With this background, it is appropriate to re-evaluate whether DFT testing still should be routinely performed at the initial ICD insertion procedure.Multiple arguments and lines of evidence support the routine evaluation of DFTs at ICD insertion (1-3). The prospective randomized trials demonstrating efficacy of the ICD for primary and secondary prevention of sudden death have required DFT testing. Evaluation of DFTs allows verification of sensing, integrity of the high-voltage system, and programming lower initial shock energy for ventricular fibrillation at 10 J over the DFT (1-3). Testing of defibrillation efficacy represent a historical standard of care, and eliminating the DFT testing may present a medical legal issue for the physician performing the implantation (1-3). However, the evidence supporting continued DFT testing is limited by the absence of a prospective randomized trial with appropriate clinical outcomes.The arguments and evidence against the determination of the DFTs include the risks of major complications related to the testing (1-18). Death, stroke, myocardial infarction, and anesthesia-related complications related to DFT determination are reported in Ͻ1% of implants. However, registry and observational data may under-report the frequency of complications. Inadequate safety margins with current ICDs are ver...

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ICD Efficacy Should Be Evaluated at Implantation

Cited by 3 publications

References 54 publications

Automated Vulnerability Testing Identifies Patients With Inadequate Defibrillation Safety Margin

Automated Vulnerability Testing Identifies Patients With Inadequate Defibrillation Safety Margin

Intraoperative Defibrillation Testing Should Not Be Generally Abandoned for All ICD Procedures—A Multicenter Study on 4,572 Consecutive Patients

Defibrillation Testing

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