P1689Prognostic significance of different patterns and amplitude of QRS fragmentation in patients with implantable defibrillator in primary prevention

Background: Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease, and sudden cardiac death represents an important mode of death in these patients. Data evaluating the implantable cardioverter defibrillator (ICD) in this patient population remain scarce. Methods: A Nationwide French Registry including all patients with tetralogy of Fallot with an ICD was initiated in 2010 by the French Institute of Health and Medical Research. The primary time to event end point was the time from ICD implantation to first appropriate ICD therapy. Secondary outcomes included ICD-related complications, heart transplantation, and death. Clinical events were centrally adjudicated by a blinded committee. Results: A total of 165 patients (mean age, 42.2±13.3 years, 70.1% males) were included from 40 centers, including 104 (63.0%) in secondary prevention. During a median (interquartile range) follow-up of 6.8 (2.5–11.4) years, 78 (47.3%) patients received at least 1 appropriate ICD therapy. The annual incidence of the primary outcome was 10.5% (7.1% and 12.5% in primary and secondary prevention, respectively; P =0.03). Overall, 71 (43.0%) patients presented with at least 1 ICD complication, including inappropriate shocks in 42 (25.5%) patients and lead dysfunction in 36 (21.8%) patients. Among 61 (37.0%) patients in primary prevention, the annual rate of appropriate ICD therapies was 4.1%, 5.3%, 9.5%, and 13.3% in patients with, respectively, 0, 1, 2, or ≥3 guidelines-recommended risk factors. QRS fragmentation was the only independent predictor of appropriate ICD therapies (hazard ratio, 3.47 [95% CI, 1.19–10.11]), and its integration in a model with current criteria increased the 5-year time-dependent area under the curve from 0.68 to 0.81 ( P =0.006). Patients with congestive heart failure or reduced left ventricular ejection fraction had a higher risk of nonarrhythmic death or heart transplantation (hazard ratio, 11.01 [95% CI, 2.96–40.95]). Conclusions: Patients with tetralogy of Fallot and an ICD experience high rates of appropriate therapies, including those implanted in primary prevention. The considerable long-term burden of ICD-related complications, however, underlines the need for careful candidate selection. A combination of easy-to-use criteria including QRS fragmentation might improve risk stratification. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03837574.

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Abstract 157: Assessing Physician Knowledge Regarding Indications for a Primary Prevention Implantable Defibrillator and Potential Barriers for Referral

Circulation Cardiovascular Quality and Outcomes ◽

10.1161/circoutcomes.10.suppl_3.157 ◽

2017 ◽

Vol 10 (suppl_3) ◽

Author(s):

Rochelle C Bernier ◽

Satish R Raj ◽

Lucy Reyes ◽

Michael Sauve ◽

Glen L Sumner ◽

...

Keyword(s):

Cost Effectiveness ◽

Primary Prevention ◽

Care Pathway ◽

Age Groups ◽

Implantable Defibrillator ◽

University Hospital ◽

Implantable Cardioverter Defibrillators ◽

Potential Barriers ◽

General Internists ◽

Physician Knowledge

Background: Primary prevention implantable cardioverter defibrillators (ICD) are under-utilized despite multiple clinical trials that demonstrated reduced mortality and cost-effectiveness in patients at risk for sudden cardiac death. Our objectives were to determine physician knowledge about primary prevention ICD guidelines and to identify potential barriers impacting referral rates. Methods: The Cardiovascular Arrhythmia and Stroke Working Group from Alberta, Canada developed a web- based survey as part of a quality assurance initiative to aid in the design of a complex device care pathway. The survey consisted of five case scenarios regarding primary prevention ICD guidelines and a list of potential barriers for ICD referral. Through expert consensus, case scenarios were developed based on current device guidelines. The survey was administered to physicians encountering patients eligible for ICD therapy, including General Internists and Cardiologists with Alberta Medical Association membership and Cardiology residents. Results: The survey was completed by 109 of 799 (response rate =14%). Of those, 55% were General Internists, 32% were Cardiologists and 13% were Cardiology residents. The majority of physicians were male (62%) and practicing at a University Hospital (66%). Overall, 34% of participants answered all case scenarios correctly. A correct answer on all five case scenarios was demonstrated by 62.5% of Cardiologists, 61.5% of Cardiology residents and 16% of General Internists (p<0.0001). Figure 1 demonstrates significant differences regarding perceived barriers for ICD referral among physician groups (p<0.0001). There were also significant differences among physician age groups (p<0.0001), with younger physicians reporting more barriers. The most common barriers among all physician groups were cost- effectiveness (55%), concerns regarding knowledge of ICD guidelines (47%) and the risk of inappropriate shocks (41%). Conclusion: Knowledge of indications for a primary prevention ICD is poor and a recognized barrier among physicians who may refer patients for device therapy. Adequate knowledge translation of ICD guidelines is crucial in order to improve ICD utilization.

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