Left Ventricular Structural Predictors of Sudden Cardiac Death
| Status: | Recruiting |
|---|---|
| Conditions: | Peripheral Vascular Disease, Cardiology |
| Therapuetic Areas: | Cardiology / Vascular Diseases |
| Healthy: | No |
| Age Range: | 21 - 80 |
| Updated: | 2/14/2019 |
| Start Date: | October 2003 |
| End Date: | June 2020 |
| Contact: | Jeannette Walker, RN |
| Email: | jhoefli1@jhmi.edu |
| Phone: | 410-502-7310 |
Left Ventricular Structural Predictors of Sudden Cardiac Death [Substudy of: Functional Energetics and Imaging for Phenotypic Characterization of Patients at Risk for Sudden Cardiac Death, See Also NCT000181233]
Sudden cardiac death (SCD) poses a significant health care challenge with high annual
incidence and low survival rates. Implantable cardioverter defibrillators (ICDs) prevent SCD
in patients with poor heart function. However, the critical survival benefit afforded by the
devices is accompanied by short and long-term complications and a high economic burden.
Moreover, in using current practice guidelines of reduced heart function, specifically left
ventricular ejection fraction (LVEF)≤35%, as the main determining factor for patient
selection, only a minority of patients actually benefit from ICD therapy (<25% in 5 years).
There is an essential need for more robust diagnostic approaches to SCD risk stratification.
This project examines the hypothesis that structural abnormalities of the heart itself, above
and beyond global LV dysfunction, are important predictors of SCD risk since they indicate
the presence of the abnormal tissue substrate required for the abnormal electrical circuits
and heart rhythms that actually lead to SCD. Information about the heart's structure will be
obtained from cardiac magnetic resonance imaging and used in combination with a number of
other clinical risk factors to see if certain characteristics can better predict patients at
risk for SCD.
incidence and low survival rates. Implantable cardioverter defibrillators (ICDs) prevent SCD
in patients with poor heart function. However, the critical survival benefit afforded by the
devices is accompanied by short and long-term complications and a high economic burden.
Moreover, in using current practice guidelines of reduced heart function, specifically left
ventricular ejection fraction (LVEF)≤35%, as the main determining factor for patient
selection, only a minority of patients actually benefit from ICD therapy (<25% in 5 years).
There is an essential need for more robust diagnostic approaches to SCD risk stratification.
This project examines the hypothesis that structural abnormalities of the heart itself, above
and beyond global LV dysfunction, are important predictors of SCD risk since they indicate
the presence of the abnormal tissue substrate required for the abnormal electrical circuits
and heart rhythms that actually lead to SCD. Information about the heart's structure will be
obtained from cardiac magnetic resonance imaging and used in combination with a number of
other clinical risk factors to see if certain characteristics can better predict patients at
risk for SCD.
Sudden cardiac death (SCD) poses a significant health care challenge with high annual
incidence and low survival rates. Implantable cardioverter defibrillators (ICDs) prevent SCD
in patients with left ventricular (LV) systolic dysfunction. However, the critical survival
benefit afforded by the devices is accompanied by short and long-term complications and a
high economic burden. Moreover, in using current practice guidelines of LV ejection fraction
(LVEF)≤35% as the main determining factor for patient selection, only a minority of patients
actually benefit from ICD therapy (<25% in 5 years). There is an essential need for more
robust diagnostic approaches to SCD risk stratification.
This project examines the hypothesis that LV structural abnormalities above and beyond global
LV dysfunction are important predictors of SCD risk since they indicate the presence of
abnormal pathophysiologic substrate required for the ventricular arrhythmogenicity leading to
SCD. This premise is supported by pre-clinical models and limited patient cohort studies
examining the contribution of individual LV structural indices. However, there has been no
prospective study of primary prevention ICD candidates in sufficiently large numbers to
investigate the incremental value of a comprehensive assessment of LV structure on SCD risk
over and above that of LVEF and readily available demographic and clinical variables.
LV structure can be quantified in detail using cardiac magnetic resonance imaging with late
gadolinium enhancement (CMR-LGE). Specifically, accurate assessment of global LV function,
volumes, mass, geometry, and infarct/scar characteristics are feasible and obtainable
clinically in a single examination. We aim to examine whether or not any of these CMR indices
or combination of indices are better able to discriminate between patients with high versus
low susceptibility to SCD within the broader population of reduced LVEF patients. If the
results of these studies demonstrate that LV structure is an important prognostic risk
factor, it may be then be possible to more specifically focus ICD therapy to those who are
most likely to benefit and avoid unnecessary device implantations.
incidence and low survival rates. Implantable cardioverter defibrillators (ICDs) prevent SCD
in patients with left ventricular (LV) systolic dysfunction. However, the critical survival
benefit afforded by the devices is accompanied by short and long-term complications and a
high economic burden. Moreover, in using current practice guidelines of LV ejection fraction
(LVEF)≤35% as the main determining factor for patient selection, only a minority of patients
actually benefit from ICD therapy (<25% in 5 years). There is an essential need for more
robust diagnostic approaches to SCD risk stratification.
This project examines the hypothesis that LV structural abnormalities above and beyond global
LV dysfunction are important predictors of SCD risk since they indicate the presence of
abnormal pathophysiologic substrate required for the ventricular arrhythmogenicity leading to
SCD. This premise is supported by pre-clinical models and limited patient cohort studies
examining the contribution of individual LV structural indices. However, there has been no
prospective study of primary prevention ICD candidates in sufficiently large numbers to
investigate the incremental value of a comprehensive assessment of LV structure on SCD risk
over and above that of LVEF and readily available demographic and clinical variables.
LV structure can be quantified in detail using cardiac magnetic resonance imaging with late
gadolinium enhancement (CMR-LGE). Specifically, accurate assessment of global LV function,
volumes, mass, geometry, and infarct/scar characteristics are feasible and obtainable
clinically in a single examination. We aim to examine whether or not any of these CMR indices
or combination of indices are better able to discriminate between patients with high versus
low susceptibility to SCD within the broader population of reduced LVEF patients. If the
results of these studies demonstrate that LV structure is an important prognostic risk
factor, it may be then be possible to more specifically focus ICD therapy to those who are
most likely to benefit and avoid unnecessary device implantations.
Inclusion Criteria:
- LVEF≤35%, referred clinically for ICD insertion for primary prevention purposes (i.e.
no prior history of sustained ventricular arrhythmias)
- Between the ages of 21 and 80 years old
- Permission of the patient's clinical attending physician
Exclusion Criteria:
- Patients who refuse or are unable to give consent.
- Individuals with contraindications to MRI (i.e. implanted metallic objects such as
pre-existing cardiac pacemakers, cerebral clips or indwelling metallic projectiles)
- Minors.
- Pregnant women.
- NYHA Class IV heart failure.
- Chronic renal insufficiency with creatinine clearance<60 ml/min; acute renal
insufficiency of any severity
- Claustrophobia
- Prior adverse reaction to gadolinium-based contrast
We found this trial at
2
sites
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Baltimore, Maryland 21287
Principal Investigator: Katherine Wu, MD
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