Congestive Heart Failure, Ischemic Cardiomyopathy, Sudden Cardiac Arrest
Conditions
Keywords
Positron Emission Tomography, Sympathetic Innervation, Sudden Death, Ventricular Fibrillation, LMI-1195, Ischemic Cardiomyopathy, Risk Prediction
Brief summary
Sudden cardiac death continues to be a major contributor to mortality in patients with ischemic cardiomyopathy. While implantable defibrillators can prevent death from ventricular arrhythmias, our current approach to identify patients at highest risk primarily rests on demonstrating a reduction in left ventricular ejection fraction less than 35%. The purpose of this observational cohort study is to prospectively test whether this can be enhanced by quantifying the amount of sympathetic denervation, left ventricular end-diastolic volume or brain natriuretic peptide levels.
Detailed description
Using current guidelines based primarily on ejection fraction (EF), only one-quarter of patients receiving an implantable cardiac defibrillator (ICD) for the primary prevention of sudden cardiac arrest (SCA) require appropriate ICD therapy within 5 years. The NIH-sponsored PAREPET study (Prediction of ARrhythmic Events with Positron Emission Tomography, ClinicalTrials.gov, NCT01400334) identified four independent risk factors that predict SCA or ICD equivalent in patients with ischemic cardiomyopathy. Using retrospectively defined cut-points, the absence of these risk factors identified 38% of the cohort with a very low risk of SCA (\<1% per year). This rate is actually lower than the 1.5-2% annual rate of SCA among patients with coronary artery disease and mild left ventricular (LV) dysfunction, who are not considered candidates for a primary prevention ICD. This proposal will prospectively determine whether these risk factors can form the basis of a clinically applicable approach to identify a subgroup of patients who are candidates for an ICD, but are at low enough risk of SCA to have an ICD safely withheld. Our long-term goal is to develop better approaches to identify patients with coronary artery disease who are most likely to benefit from prevention of SCA with placement of an implantable defibrillator.
Interventions
A cardiac PET scan will be obtained to quantify the percentage of the left ventricle that is denervated and has reduced uptake of the sympathetic nerve tracer \[18F\]-LMI1195
Sponsors
Study design
Eligibility
Inclusion criteria
* Coronary artery disease (by cardiac catheterization or definite myocardial infarction) * ICD implantation for the primary prevention of SCA * Primary prevention patients with a Biventricular ICD * Eligible immediately when this is placed to prevent dysynchrony related to intermittent RV pacing and the native QRS duration is ≤ 130 msec in the absence of pacing. * Eligible 6 months after implantation when the native QRS duration prior to implant is \>130 msec or there is persistent RV pacing. * Optimal medical therapy for heart failure.
Exclusion criteria
* Plans for coronary revascularization (due to the independent impact on SCA) * Contraindication for PET (i.e. claustrophobia, pregnancy, physical limitation) * Tricyclic antidepressant use (inhibits norepinephrine and LMI1195 uptake) * Comorbidities limiting life expectancy \<2yr. * Age \<18 years or inability to provide informed consent * Primary prevention ICD/BiV recipients who have received an appropriate ICD shock prior to enrollment
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Sudden Cardiac Arrest Events | Through study completion, an average of 3 years | The primary end-point will be SCA or ICD equivalent as used in PAREPET. This will consist of ICD therapies for ventricular fibrillation or ventricular tachycardia \>240 bpm, and adjudicated arrhythmic death using the modified Hinkle-Thaler criteria. |
Countries
United States
Contacts
University at Buffalo