Ignite Creation Date:
2024-05-05 @ 12:02 PM
Last Modification Date:
2024-10-26 @ 9:19 AM
Study NCT ID:
NCT00224809
Status:
COMPLETED
Last Update Posted:
2014-02-19
First Post:
2005-09-21
Brief Title:
Impact of Medical and Surgical Therapy on Functional Mitral Regurgitation
Sponsor:
Baylor Research Institute
Organization:
Baylor Research Institute
Study Overview
Official Title:
Functional Mitral Regurgitation in STICH
Status:
COMPLETED
Status Verified Date:
2007-12
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:
The Transesophageal Echocardiography TEE Surgical Treatment of Ischemic Heart Failure STICH ancillary study will define the mechanisms of functional mitral regurgitation MR by TEE in patients with ischemic cardiomyopathy and the impact of therapy medical coronary artery bypass grafting CABG or CABG plus surgical ventricular restoration SVR on mechanism and severity of MR Severity of the effect of functional MR on clinical outcomes will also be examined The TEE STICH study will address four specific aims that will focus on defining the following 1 the mechanisms of functional MR in ischemic cardiomyopathy 2 the effect of therapy on the mechanism and severity of functional MR 3 myocardial viability on functional MR and its response to treatment and 4 the effect of MR on prognosis in ischemic cardiomyopathy
Detailed Description:
BACKGROUND
Functional MR is a common complication of ischemic heart disease Two large studies have confirmed an adverse effect of functional MR on survival after a heart attack However studies in heart failure HF are small and mainly limited to patients with non-ischemic cardiomyopathy Recent animal studies have challenged the traditional concept that functional MR is a consequence of mitral annular dilation instead suggesting that functional MR is due to leaflet tethering by outward expansion of the left ventricular wall LV remodeling This has critical implications regarding the correct surgical approach to correcting functional MR To date no large prospective study has examined the mechanisms of functional MR in ischemic cardiomyopathy nor has the interaction between mechanism and prognosis been explored This is a crucial knowledge gap because 1 70 of HF cases are caused by ischemic heart disease and 2 functional MR occurs in around 60 of patients with ischemic cardiomyopathy This study aims to fill these gaps by defining the mechanisms of functional MR by TEE in a large clinical trial of patients with ischemic cardiomyopathy participating in the STICH study The STICH study will address the following two key hypotheses of therapeutic strategy in the management of patients with symptomatic HF LV dysfunction and coronary artery disease CAD amenable to CABG 1 surgical coronary revascularization in addition to aggressive medical HF management will have long-term mortality morbidity quality of life or cost benefits beyond aggressive medical management alone and 2 early surgical ventricular shape restoration SVR in combination with CABG will improve outcome compared to coronary revascularization alone and medical therapy alone The study will also address the role of LV size and function including myocardial viability as a predictor of subsequent events over 3 years
The STICH study affords a unique opportunity to specifically evaluate the mechanism and prognosis of functional MR in a large group of patients with HF due to ischemic cardiomyopathy The study design of STICH allows exploring the interactions between the mechanism of functional MR therapy and prognosis For example it is not known whether all patients with functional MR have an adverse prognosis or whether their prognosis is related to specific mechanisms or severity In patients undergoing CABG it is not known which patients with functional MR will require valve repair or which ones will do well without it It is also not known whether SVR reduces MR severity more than medical therapy and by what mechanism It is possible that improvement in functional MR is a consequence of reversed LV remodeling which is known to be related to myocardial viability independent of specific therapy These important questions are addressed by the TEE STICH study an ancillary study to the STICH study
DESIGN NARRATIVE
The following four specific aims will be tested
Specific Aim 1 This study will define the mechanism of functional MR in ischemic cardiomyopathy Null Hypothesis There is no difference in measurements of the mitral valve apparatus known to be associated with functional MR in ischemic cardiomyopathy among patients with different degrees of functional MR To test this hypothesis this study will compare measurements of annulus size and leaflet tethering in three groups of patients those without MR those with mild MR effective regurgitant orifice area EROA less than 02 cm² and those with at least moderate MR EROA less than 02 cm² The six specific measurements of MR mechanism include the following 1 diastolic mitral annulus area 2 percent of systolic annular contraction 3 leaflet tenting area 4 papillary muscle tethering distance 5 papillary muscle separation distance and 6 the primary chordal separation angle
Specific Aim 2 This study will define the effect of therapy on mechanism and severity of functional MR Null Hypothesis There will be no difference in measurements of the mechanism and severity of moderate functional MR before and after treatment in the three treatment groups medicine CABG and CABG plus SVR To test this hypothesis this study will compare the change in measurements of MR mechanism see above list and severity EROA and volume of the chest wall VCW before and at a 2-year follow-up in the three treatment groups The primary endpoint for this analysis will be long-term survival
Specific Aim 3 This study will evaluate the effect of functional MR on prognosis Null Hypothesis The presence and severity of functional MR does not predict the following 1 long-term survival and 2 the combined endpoint of death cardiac transplantation automatic implantable cardioverter defibrillator AICD countershock hospitalization due to heart failure or subsequent mitral valve repair or replacement
Specific Aim 4 This study will evaluate the effect of myocardial viability on mechanism of functional MR Null Hypothesis The mechanism of moderate MR will be no different in patients with or without myocardial viability by single photon emission computed tomography SPECT imaging All patients who have undergone SPECT imaging done as part of the parent study will be studied The grouping variables will be the presence or absence of myocardial viability as determined by the SPECT core lab
Functional MR is a common complication of ischemic heart disease Two large studies have confirmed an adverse effect of functional MR on survival after a heart attack However studies in heart failure HF are small and mainly limited to patients with non-ischemic cardiomyopathy Recent animal studies have challenged the traditional concept that functional MR is a consequence of mitral annular dilation instead suggesting that functional MR is due to leaflet tethering by outward expansion of the left ventricular wall LV remodeling This has critical implications regarding the correct surgical approach to correcting functional MR To date no large prospective study has examined the mechanisms of functional MR in ischemic cardiomyopathy nor has the interaction between mechanism and prognosis been explored This is a crucial knowledge gap because 1 70 of HF cases are caused by ischemic heart disease and 2 functional MR occurs in around 60 of patients with ischemic cardiomyopathy This study aims to fill these gaps by defining the mechanisms of functional MR by TEE in a large clinical trial of patients with ischemic cardiomyopathy participating in the STICH study The STICH study will address the following two key hypotheses of therapeutic strategy in the management of patients with symptomatic HF LV dysfunction and coronary artery disease CAD amenable to CABG 1 surgical coronary revascularization in addition to aggressive medical HF management will have long-term mortality morbidity quality of life or cost benefits beyond aggressive medical management alone and 2 early surgical ventricular shape restoration SVR in combination with CABG will improve outcome compared to coronary revascularization alone and medical therapy alone The study will also address the role of LV size and function including myocardial viability as a predictor of subsequent events over 3 years
The STICH study affords a unique opportunity to specifically evaluate the mechanism and prognosis of functional MR in a large group of patients with HF due to ischemic cardiomyopathy The study design of STICH allows exploring the interactions between the mechanism of functional MR therapy and prognosis For example it is not known whether all patients with functional MR have an adverse prognosis or whether their prognosis is related to specific mechanisms or severity In patients undergoing CABG it is not known which patients with functional MR will require valve repair or which ones will do well without it It is also not known whether SVR reduces MR severity more than medical therapy and by what mechanism It is possible that improvement in functional MR is a consequence of reversed LV remodeling which is known to be related to myocardial viability independent of specific therapy These important questions are addressed by the TEE STICH study an ancillary study to the STICH study
DESIGN NARRATIVE
The following four specific aims will be tested
Specific Aim 1 This study will define the mechanism of functional MR in ischemic cardiomyopathy Null Hypothesis There is no difference in measurements of the mitral valve apparatus known to be associated with functional MR in ischemic cardiomyopathy among patients with different degrees of functional MR To test this hypothesis this study will compare measurements of annulus size and leaflet tethering in three groups of patients those without MR those with mild MR effective regurgitant orifice area EROA less than 02 cm² and those with at least moderate MR EROA less than 02 cm² The six specific measurements of MR mechanism include the following 1 diastolic mitral annulus area 2 percent of systolic annular contraction 3 leaflet tenting area 4 papillary muscle tethering distance 5 papillary muscle separation distance and 6 the primary chordal separation angle
Specific Aim 2 This study will define the effect of therapy on mechanism and severity of functional MR Null Hypothesis There will be no difference in measurements of the mechanism and severity of moderate functional MR before and after treatment in the three treatment groups medicine CABG and CABG plus SVR To test this hypothesis this study will compare the change in measurements of MR mechanism see above list and severity EROA and volume of the chest wall VCW before and at a 2-year follow-up in the three treatment groups The primary endpoint for this analysis will be long-term survival
Specific Aim 3 This study will evaluate the effect of functional MR on prognosis Null Hypothesis The presence and severity of functional MR does not predict the following 1 long-term survival and 2 the combined endpoint of death cardiac transplantation automatic implantable cardioverter defibrillator AICD countershock hospitalization due to heart failure or subsequent mitral valve repair or replacement
Specific Aim 4 This study will evaluate the effect of myocardial viability on mechanism of functional MR Null Hypothesis The mechanism of moderate MR will be no different in patients with or without myocardial viability by single photon emission computed tomography SPECT imaging All patients who have undergone SPECT imaging done as part of the parent study will be studied The grouping variables will be the presence or absence of myocardial viability as determined by the SPECT core lab
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 |
|---|---|---|---|
| R01HL072430 | NIH | None | httpsreporternihgovquickSearchR01HL072430 |