Defibrillation Testing should be routinely performed at the time of ICD implantation. Jeff Healey MD, MSc, FHRS McMaster University

Transcription

1 Defibrillation Testing should be routinely performed at the time of ICD implantation Jeff Healey MD, MSc, FHRS McMaster University

2 Presenter Disclosure Information Jeff S. Healey, MD, MSc, McMaster University, Canada Sub-clinical atrial tachyarrhythmia and stroke FINANCIAL DISCLOSURES: Grants/Research Support: Boston Scientific, St. Jude Medical, Boehringer Ingelheim and Astra-Zeneca The ASSERT trial was sponsored by St. Jude Medical Principal Investigator of SIMPLE randomized trial of DFT Testing at time of ICD implantation Advisory Boards: Sanofi-Aventis, Boehringer Ingelheim UNLABELED/UNAPPROVED USES DISCLOSURE: None

3 Why Conduct Defibrillation Testing? Ensure integrity of HV circuit Ensure sensing during VF Ensure success of defibrillation Was performed in all pivotal ICD trials Included on product labeling Still considered by many as standard of care 3

4 Drawbacks of DT? Takes time Resource requirements (anesthesia) Risk of complications Shortcomings as a surrogate for clinical shock efficacy

5 Why We Should Routinely Perform DT? Shocks do fail and we cannot easily predict in which patients. Risk of complications is overstated Incremental costs are small In most cases when DT not performed, no true contra-indication exists DT may identify uncommon, but potentially fatal problems with ICD function

6 USA Consecutive Patients Type of Testing Done Full Defibrillation Threshold (n = 129) 2003 Clinical First Shock Efficacy* 91 % Defibrillation Safety Margin (n = 503) 91 % No Testing (n = 203) 92 % Pires LA, J. Cardiovasc. Electrophysiol 2006; 17(2): St. John Hospital, Detroit, Michigan, USA * Every clinical episode successful treated with 1 or 2 shocks

7 Retrospective chart review of all ICDs implanted at LHSC over 4 year period Determined # of cases in which DFT testing made a difference to final ICD programming Complete implant data obtained on 293 patients 168 patients with DFT testing and full data Average age 61.6 years 77% male

8 Predictors of Failed DFT Variable Odds Ratio (95% confidence interval) Male 0.96 ( ) Age (per year) 0.98 ( ) Ejection fraction vs > ( ) Ejection fraction <20 vs > ( ) Coronary artery disease 0.93 ( ) Dilated cardiomyopathy 2.83 ( ) Syncope 3.47 ( ) LVEDD >64mm vs <=64mm 0.56 ( ) Amiodarone 4.56 ( )* Increased threshold by 1mV 0.70 ( ) Increased R wave by 1 V 0.94 ( ) 1. Poor ability to predict 2. Patients at increased risk of failed DFT also at increased risk of DFT-related complications Table 4: Independent Predictors of DFT/LED difference Variable Difference in mean DFT/LED (V) if variable present p-value Dilated cardiomyopathy Amiodarone

9 How Dangerous is DT?

10 Birnie DH. Canadian Experience Heart Rhythm 2008, 5(3) 3 DFT-related deaths/15254 cases indicating incidence of 0.01% 5 DFT-related strokes Prolonged resuscitation: requirement for external cardiac massage, or > than 1 external rescue shock to rescue a patient 27/15254 = 0.18% Two patients had significant clinical sequelae after prolonged resuscitation.

11 Safety of DFT CREDIT Registry; JCE 2010; 21(2) Complication All patients (N = 361) DFT (n = 230) No DFT (N = 131) Stroke 2 (0.6%) 1 (0.4%) 1 (0.8%) MI 0 (0%) 0 (0%) 0 (0%) Heart Failure 15 (4%) 9 (4%) 6 (5%) Death 1 (0.3%) 0 (0%) 1(0.8%) Prolonged Hypotension 7 (1.9%) 7 (3%) 0 (0%) Atrial Arrhythmias 7 (1.9%) 5 (2%) 2 (1.5%) Modern Era: Short DT procedures, low rate of general anesthesia abbreviated testing

12 Safe ICD Trial Brignole et al. JACC 2012; July 24 th.

13 RAFT-DFT Sub-Study Healey et al, JCE 2012; July 12 th Patients with NYHA-II HF, prolonged QRS and LVEF 35%, randomized to ICD±CRT 145 patients RANDOMIZED to DT or no DT at time of ICD implant No patient in either group suffered: Death, stroke, embolism, MI, heart failure, need for CPR or intubation or unplanned ICU stay

14 RAFT-DFT Sub-Study Healey et al, JCE 2012; July 12 th Symptomatic hypotension requiring inotropes or vasopressors > 15 minutes 4% of DT patients, 0% of no DT patients (p=0.25) No difference in the use of invasive arterial pressure monitoring (38% vs. 25%, p=0.11) or endotracheal intubation (7% vs. 11%, p=0.55) Hospital length of stay not different: DT: 20.2 ± 26.3 hours vs. no DT: 21.3 ± 23.0 hours, p=0.79

15 Observational Data Resource Utilization: CREDIT Registry; JCE 2010; 21(2) DFT patients more likely to have: overnight hospital stay: 81% vs. 44%, p= Anesthesiologist involved: 83% vs. 47%, p=0.001 IV propofol: 73% vs. 21%, p=0.001

16 Cost of DFT CREDIT Registry; JCE 2010; 21(2) Costs (Canadian $) DFT (n=230) No DFT (n=131) P-Value Device 22,945 22, Procedure Professional Complications LOS Total 25,778 24,

17 Safe ICD Trial Brignole et al. JACC 2012; July

18 DFT by Centre: Ontario ICES Registry Healey JS, JCE 2010; 21(12) Testing-New Implants 71% Testing-Replacements 34%

19 Reasons Given for NOT Testing CREDIT Registry; JCE 2010; 21(2) Category % of ALL Pts. Reason Number Unnecessary 16 % Replacement 41 Primary Prev. 16 Unsafe 14 % AF 27 Severe CAD 6 Recent CVA 5 Thrombus 4 Unstable 4 Pulm HTN 1 Pregnancy 1 Anesth. Prob. 1

20 Reasons Given for NOT Testing Healey JS, JCE 2010; 21(2) Category % of ALL Pts. Reason Number Impractical 7 % No Anesth. 26 Preference 3% Physician 5 Patient 3 Not Documented * May have been more than 1 reason per patient 2

21 Closing Arguments DT was part of all ICD trials standard of care Failed shocks occur, hard to predict Risk of DT actually small in modern era Incremental costs of DT also small A growing number of ICDs are implanted without DT; however, this change in practice is not supported by evidence and patients typically do not have any absolute contraindication to DT