Ignite Creation Date:
2024-05-05 @ 5:07 PM
Last Modification Date:
2024-10-26 @ 9:28 AM
Study NCT ID:
NCT00399503
Status:
COMPLETED
Last Update Posted:
2016-06-14
First Post:
2006-11-13
Brief Title:
Assessment of Noninvasive Methods to Identify Patients at Risk of Serious Arrhythmias After a Heart Attack
Sponsor:
University of Calgary
Organization:
University of Calgary
Study Overview
Official Title:
Risk Estimation Following Infarction Noninvasive Evaluation REFINE
Status:
COMPLETED
Status Verified Date:
2006-11
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
This study evaluates the usefulness of noninvasive tests of the structure of the heart and the nervous system controlling the heart It will assess whether combining tests that evaluate heart structure with others that measure the nervous system controlling the heart will identify most patients who develop serious heart rhythm problems after a heart attack
Detailed Description:
Background Sudden cardiac death SCD kills 450000 North Americans each year Patients with a history of myocardial infarction MI are at particular risk Concurrent alterations in myocardial structure autonomic tone appear important for the development of the arrhythmias leading to SCD
Given the grave consequences of SCD an ideal testing procedure should identify most of those at risk sensitive correctly classify risk accurate Since 90 of patients who suffer serious arrhythmias post-MI have at least mild left ventricular LV dysfunction ejection fraction EF 050 this is an optimal group to study
While noninvasive tests have been developed to estimate SCD risk prior approaches have failed to 1 identify the majority of patients at risk for serious arrhythmias insensitive 2 evaluate temporal changes in parameters 3 identify the optimal timing for risk assessment post-MI 4 develop a widely-applicable screening tool This has resulted in a failure to delivery effective therapies eg defibrillator in a cost-effective manner
Hypotheses Primary Concurrent evaluation of electrical structure autonomic tone will accurately identify most post-MI patients at risk of serious arrhythmic events Secondary 1 assessment later 16 weeks provides more prognostic information than assessment early post-MI 4 weeks 2 a single multi-parameter test procedure can be developed and 3 individually repolarization alternans provides the most prognostic information
Methods 350 persons with a recent MI 31 days EF 050 will undergo testing early 4 weeks intermediate 8 weeks late 16 weeks post-MI
Four techniques assess cardiac structure spectral T-wave alternans TWA modified moving average TWA signal-averaged SA ECG nuclear ejection fraction Three others evaluate autonomic tone baroreceptor sensitivity BRS heart rate variability HRV and Heart Rate Turbulence HRT
Data Collection Outcomes Patients will be recruited over 24 months followed biannually for four years Committee blinded endpoint classification central laboratory data analysis will be utilized A composite of resuscitated cardiac arrest and cardiac mortality is the primary outcome The components resuscitated non-resuscitated cardiac arrest and cardiac death are secondary outcomes
Statistical Aspects Sample Size Standard methods of description analysis will be used The capacity to accurately identify most patients at risk for serious arrhythmias will be evaluated using Cox multivariate models The primary model will include age sex EF at 8 wks important baseline medication use
Since multivariate modeling requires lower more sensitive dichotomy limits the following will be used spectral TWA positivity will be defined as a non-negative test SA-ECG QRS width 104 msec will be labeled as abnormal For HRV SDNN values 105 msec will be considered abnormal For BRS values 61 msec per mmHg will indicate impairment For HRT abnormalities in T-onset or T-slope will be considered abnormal Receiver operating characteristic curves will be used to identify a cut-point for modified moving average TWA
Assuming a 5 year 20 rate of the composite arrhythmias in patients with positive test results we have 85 power to detect a 25-fold higher risk in patients with abnormalities than those without these abnormalities
Relevance This is the first large prospective study to evaluate the utility of concurrent structural autonomic tone assessment in predicting the development of serious arrhythmias after an MI
Given the grave consequences of SCD an ideal testing procedure should identify most of those at risk sensitive correctly classify risk accurate Since 90 of patients who suffer serious arrhythmias post-MI have at least mild left ventricular LV dysfunction ejection fraction EF 050 this is an optimal group to study
While noninvasive tests have been developed to estimate SCD risk prior approaches have failed to 1 identify the majority of patients at risk for serious arrhythmias insensitive 2 evaluate temporal changes in parameters 3 identify the optimal timing for risk assessment post-MI 4 develop a widely-applicable screening tool This has resulted in a failure to delivery effective therapies eg defibrillator in a cost-effective manner
Hypotheses Primary Concurrent evaluation of electrical structure autonomic tone will accurately identify most post-MI patients at risk of serious arrhythmic events Secondary 1 assessment later 16 weeks provides more prognostic information than assessment early post-MI 4 weeks 2 a single multi-parameter test procedure can be developed and 3 individually repolarization alternans provides the most prognostic information
Methods 350 persons with a recent MI 31 days EF 050 will undergo testing early 4 weeks intermediate 8 weeks late 16 weeks post-MI
Four techniques assess cardiac structure spectral T-wave alternans TWA modified moving average TWA signal-averaged SA ECG nuclear ejection fraction Three others evaluate autonomic tone baroreceptor sensitivity BRS heart rate variability HRV and Heart Rate Turbulence HRT
Data Collection Outcomes Patients will be recruited over 24 months followed biannually for four years Committee blinded endpoint classification central laboratory data analysis will be utilized A composite of resuscitated cardiac arrest and cardiac mortality is the primary outcome The components resuscitated non-resuscitated cardiac arrest and cardiac death are secondary outcomes
Statistical Aspects Sample Size Standard methods of description analysis will be used The capacity to accurately identify most patients at risk for serious arrhythmias will be evaluated using Cox multivariate models The primary model will include age sex EF at 8 wks important baseline medication use
Since multivariate modeling requires lower more sensitive dichotomy limits the following will be used spectral TWA positivity will be defined as a non-negative test SA-ECG QRS width 104 msec will be labeled as abnormal For HRV SDNN values 105 msec will be considered abnormal For BRS values 61 msec per mmHg will indicate impairment For HRT abnormalities in T-onset or T-slope will be considered abnormal Receiver operating characteristic curves will be used to identify a cut-point for modified moving average TWA
Assuming a 5 year 20 rate of the composite arrhythmias in patients with positive test results we have 85 power to detect a 25-fold higher risk in patients with abnormalities than those without these abnormalities
Relevance This is the first large prospective study to evaluate the utility of concurrent structural autonomic tone assessment in predicting the development of serious arrhythmias after an MI
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None
Secondary IDs
| Secondary ID | Type | Domain | Link |
|---|---|---|---|
| HSFA 73-1220 | None | None | None |