Clinical trial NCT00292032: Registry of Unexplained Cardiac Arrest
Official title: Cardiac Arrest Survivors With Preserved Ejection Fraction Registry (CASPER)
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Cardiac Arrest
Long QT Syndrome
Brugada Syndrome
Catecholaminergi Polymorphic Ventricular Tachycardia
Idiopathic VentricularFibrillation
Early Repolarization Syndrome
Arrhythmogenic Right Ventricular Cardiomyopathy
Keywords: cardiac arrest
diagnosis
genetics
testing
Lead sponsor: University of British Columbia
Sponsor class: OTHER
Collaborators: name: Kingston Health Sciences Centre
name: Quebec Heart Institute
name: The Queen Elizabeth Hospital
name: St. Boniface Hospital
name: Unity Health Toronto
name: Vancouver Island Health Authority
name: Provincial Health Services Authority
name: Montreal Heart Institute
name: Ottawa Heart Institute Research Corporation
name: University of Calgary
First posted: 2006-02-15
Enrollment: 1529
Sex: ALL
Minimum age (years): 2
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Unexplained cardiac arrest patients, and first degree relatives of 1) UCA patients 2) patients with known primary electrical disease or 3) unexplained sudden death before age 60

Brief summary: The CASPER will collect systematic clinical assessments of patients and families within the multicenter Canadian Inherited Heart Rhythm Research Network. Unexplained Cardiac Arrest patients and family members will undergo standardized testing for evidence of primary electrical disease and latent cardiomyopathy along with clinical genetics screening of affected individuals based on an evident or unmasked phenotype.

Detailed description: Arrhythmias caused by congenital or acquired abnormalities of cardiac K+ or Na+ channels are increasingly recognized as a cause of syncope and sudden death. Cardiac arrest in the absence of overt structural heart disease was previously considered idiopathic ventricular fibrillation (IVF). The list of causes of "unexplained" cardiac arrest (UCA) now encompasses K+ related abnormalities (Long and Short QT, Andersen's), Na+ related (Long QT3, Brugada), Ca++ related (Catecholaminergic Polymorphic Ventricular Tachycardia-CPVT), and latent cardiomyopathy. These underlying causes of cardiac arrest are overtly familial in 30-60% of cases. Clinical detection of the underlying phenotype is crucial to direct appropriate treatment, genetic testing and screening of family members.

Phenotype recognition of the range of these rare genetic conditions includes non-invasive and invasive testing to demonstrate the hallmarks of each individual condition, and exclude common causes such as ischemic or idiopathic forms of cardiomyopathy. The outcomes from this type of testing have not been assessed in a systematic fashion in patients with UCA or their family members. Phenotype-genotype correlation is necessary to develop optimal diagnostic testing in probands and screening techniques in their family members, which will result in disease-specific therapy. Genetic testing of patients with an overt phenotype demonstrates a potentially causative mutation in 50-75% of LQTS patients, and 20% of Brugada's Syndrome patients. Despite recognized mutations with phenotypic expression models, 30-80% of patients will have negative gene screening despite overt or latent clinical disease.

The proposed project is evaluating a systematic approach to clinical assessment and genetic screening of patients and families with UCA and suspected inherited arrhythmias involving:

1. A multicenter registry of UCA patients, their family members and referred patients with familial sudden death undergoing standardized testing for evidence of primary electrical disease (PED). The single center pilot experience at the applicant's institution has proven feasibility, and has been accepted for publication in Circulation, indicating novelty. Ten centers across Canada have agreed to participate. The target is to enroll 1500 UCA probands, 1st degree family members. 1st degree relatives of autopsy negative unexplained sudden death victims.
2. Long term cardiac monitoring for (3 years) in select high-risk patients with an injectable cardiac monitor to detect potential substrate and/ore triggers for sudden death.
3. DNA/plasma collection and biobanking for stratified whole exome sequencing.

Eligibility criteria: Inclusion Criteria:

* Cardiac arrest requiring cardioversion or defibrillation.
* Syncope with documented polymorphic ventricular tachycardia felt to be responsible for the index event.
* First degree relative of an index case of UCA undergoing clinical testing.
* First degree relative of a family member with UCA or sudden death before age 35 with a negative autopsy for cause of death, presumed arrhythmic.
* First degree relative of a family member with UCA or sudden death with objective evidence of primary electrical disease, such as a diagnostic electrocardiogram (ECG), exercise test, drug infusion, or genetic testing.

Exclusion Criteria:

* Coronary artery disease (stenosis \> 50%)
* Reduced left ventricular function (left ventricular ejection fraction \[LVEF\] \< 50%)
* Event managed without an implantable cardioverter defibrillator \[ICD\] (for follow-up portion)
* Unwilling or unable to provide clinical follow-up (for follow-up portion)
* Comorbidity making survival of \> 1 year unlikely
* Persistent resting QTc \> 460 msec for males and 480 msec for females
* Reversible cause of cardiac arrest such as marked hypokalemia (\< 2.8 mmol/l) or drug overdose sufficient in gravity without other cause to explain the cardiac arrest
* Hemodynamically stable sustained monomorphic ventricular tachycardia with a QRS morphology consistent with recognized forms of idiopathic ventricular tachycardia (outflow tract or apical septal)
* Brugada's sign with e2 mm ST elevation in V1 and/or V2
* Unwilling or unable to provide consent

Primary outcomes:
measure: Developing and Testing Algorithms for Diagnostics and Treatments in Survivors of Unexplained Cardiac Arrest
timeFrame: 25 years
Secondary outcomes:
Other outcomes:
Locations:
city: Vancouver
country: Canada
facility: University of British Columbia
state: British Columbia
Study officials:
affiliation: University of British Columbia
name: Andrew D Krahn, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Krahn AD, Gollob M, Yee R, Gula LJ, Skanes AC, Walker BD, Klein GJ. Diagnosis of unexplained cardiac arrest: role of adrenaline and procainamide infusion. Circulation. 2005 Oct 11;112(15):2228-34. doi: 10.1161/CIRCULATIONAHA.105.552166. Epub 2005 Oct 3.
citation: Krahn AD, Healey JS, Chauhan V, Birnie DH, Simpson CS, Champagne J, Gardner M, Sanatani S, Exner DV, Klein GJ, Yee R, Skanes AC, Gula LJ, Gollob MH. Systematic assessment of patients with unexplained cardiac arrest: Cardiac Arrest Survivors With Preserved Ejection Fraction Registry (CASPER). Circulation. 2009 Jul 28;120(4):278-85. doi: 10.1161/CIRCULATIONAHA.109.853143. Epub 2009 Jul 13.
citation: Davies B, Bartels K, Hathaway J, Xu F, Roberts JD, Tadros R, Green MS, Healey JS, Simpson CS, Sanatani S, Steinberg C, Gardner M, Angaran P, Talajic M, Hamilton R, Arbour L, Seifer C, Fournier A, Joza J, Krahn AD, Lehman A, Laksman ZWM. Variant Reinterpretation in Survivors of Cardiac Arrest With Preserved Ejection Fraction (the Cardiac Arrest Survivors With Preserved Ejection Fraction Registry) by Clinicians and Clinical Commercial Laboratories. Circ Genom Precis Med. 2021 Jun;14(3):e003235. doi: 10.1161/CIRCGEN.120.003235. Epub 2021 May 7.
citation: Cheung CC, Davies B, Gibbs K, Laksman ZW, Krahn AD. Patch monitors for arrhythmia monitoring in patients for suspected inherited arrhythmia syndrome. J Cardiovasc Electrophysiol. 2021 Mar;32(3):856-859. doi: 10.1111/jce.14917. Epub 2021 Feb 15.
citation: Mellor G, Laksman ZWM, Tadros R, Roberts JD, Gerull B, Simpson CS, Klein GJ, Champagne J, Talajic M, Gardner M, Steinberg C, Arbour L, Birnie DH, Angaran P, Leather R, Sanatani S, Chauhan VS, Seifer C, Healey JS, Krahn AD. Genetic Testing in the Evaluation of Unexplained Cardiac Arrest: From the CASPER (Cardiac Arrest Survivors With Preserved Ejection Fraction Registry). Circ Cardiovasc Genet. 2017 Jun;10(3):e001686. doi: 10.1161/CIRCGENETICS.116.001686.
citation: Steinberg C, Padfield GJ, Champagne J, Sanatani S, Angaran P, Andrade JG, Roberts JD, Healey JS, Chauhan VS, Birnie DH, Janzen M, Gerull B, Klein GJ, Leather R, Simpson CS, Seifer C, Talajic M, Gardner M, Krahn AD. Cardiac Abnormalities in First-Degree Relatives of Unexplained Cardiac Arrest Victims: A Report From the Cardiac Arrest Survivors With Preserved Ejection Fraction Registry. Circ Arrhythm Electrophysiol. 2016 Sep;9(9):e004274. doi: 10.1161/CIRCEP.115.004274.
citation: Herman AR, Cheung C, Gerull B, Simpson CS, Birnie DH, Klein GJ, Champagne J, Healey JS, Gibbs K, Talajic M, Gardner M, Bennett MT, Steinberg C, Janzen M, Gollob MH, Angaran P, Yee R, Leather R, Chakrabarti S, Sanatani S, Chauhan VS, Krahn AD. Outcome of Apparently Unexplained Cardiac Arrest: Results From Investigation and Follow-Up of the Prospective Cardiac Arrest Survivors With Preserved Ejection Fraction Registry. Circ Arrhythm Electrophysiol. 2016 Jan;9(1):e003619. doi: 10.1161/CIRCEP.115.003619.
citation: Krahn AD, Healey JS, Chauhan VS, Birnie DH, Champagne J, Sanatani S, Ahmad K, Ballantyne E, Gerull B, Yee R, Skanes AC, Gula LJ, Leong-Sit P, Klein GJ, Gollob MH, Simpson CS, Talajic M, Gardner M. Epinephrine infusion in the evaluation of unexplained cardiac arrest and familial sudden death: from the cardiac arrest survivors with preserved Ejection Fraction Registry. Circ Arrhythm Electrophysiol. 2012 Oct;5(5):933-40. doi: 10.1161/CIRCEP.112.973230. Epub 2012 Sep 3.
citation: Krahn AD, Healey JS, Simpson CS, Chauhan VS, Birnie DH, Champagne J, Gardner M, Sanatani S, Chakrabarti S, Yee R, Skanes AC, Leong-Sit P, Ahmad K, Gollob MH, Klein GJ, Gula LJ, Sheldon RS. Sentinel symptoms in patients with unexplained cardiac arrest: from the cardiac arrest survivors with preserved ejection fraction registry (CASPER). J Cardiovasc Electrophysiol. 2012 Jan;23(1):60-6. doi: 10.1111/j.1540-8167.2011.02185.x. Epub 2011 Sep 28.
citation: Derval N, Simpson CS, Birnie DH, Healey JS, Chauhan V, Champagne J, Gardner M, Sanatani S, Yee R, Skanes AC, Gula LJ, Leong-Sit P, Ahmad K, Gollob MH, Haissaguerre M, Klein GJ, Krahn AD. Prevalence and characteristics of early repolarization in the CASPER registry: cardiac arrest survivors with preserved ejection fraction registry. J Am Coll Cardiol. 2011 Aug 9;58(7):722-8. doi: 10.1016/j.jacc.2011.04.022.