International Study of Comparative Health Effectiveness With Medical and Invasive Approaches (ISCHEMIA)
BACKGROUND:
Evidence supporting a routine invasive practice paradigm for patients with stable ischemic
heart disease (SIHD) is outdated. In strategy trials conducted in the 1970s, coronary artery
bypass grafting (CABG) improved survival as compared with no CABG in SIHD patients with
high-risk anatomic features. The relevance of these studies today is speculative because
contemporary secondary prevention—aspirin, beta-blockers, statins, ACE inhibitors, and
lifestyle interventions—were used minimally if at all. Subsequent trials have compared
percutaneous coronary intervention (PCI) with medical therapy, as PCI has replaced CABG as
the dominant method of revascularization for SIHD. To date, PCI has not been shown to reduce
death or myocardial infarction (MI) compared with medical therapy in SIHD patients.
COURAGE and BARI 2D, the two largest trials comparing coronary revascularization vs. medical
therapy in SIHD patients, found that among patients selected on the basis of coronary
anatomy after cath, an initial management strategy of coronary revascularization (PCI, PCI
or CABG, respectively) did not reduce the primary endpoints of death or MI (COURAGE), or
death (BARI 2D) compared with OMT alone. These data suggest, but do not prove, that routine
cath--which often leads to ad hoc PCI through the diagnostic-therapeutic cascade--may not be
required in SIHD patients. However, most patients enrolled in COURAGE and BARI 2D who had
ischemia level documented at baseline had only mild or moderate ischemia, leaving open the
question of the appropriate role of cath and revascularization among higher risk patients
with more severe ischemia. Observational data suggest that revascularization of patients
with moderate-to-severe ischemia is associated with a lower mortality than medical therapy
alone, but such data cannot establish a cause and effect relationship. In clinical practice
only about half such patients are referred for cath, indicating equipoise. Furthermore,
analysis of outcomes for 468 COURAGE patients with moderate-to-severe ischemia at baseline
did not reveal a benefit from PCI. This issue cannot be resolved using available data
because all prior SIHD strategy trials enrolled patients after cath, introducing undefined
selection biases (e.g., highest risk patients not enrolled) and making translation of study
results problematic for clinicians managing patients who have not yet had cath.
A clinical trial in SIHD patients uniformly at higher risk (which could not have been
performed before COURAGE and BARI 2D results were available) is needed to inform optimal
management for such patients.
DESIGN NARRATIVE:
The study protocol is final, and was distributed to sites February 2012. Study protocol v2.0
was approved in January 2014.
PARTICIPATING COUNTRIES:
North America
- Canada
- Mexico
- USA (~150 sites)
South America
- Argentina
- Brazil
- Chile
- Peru
Asia
- China
- India
- Japan
- Singapore
- Taiwan
- Thailand
- Russian Federation
Pacifica
- Australia
- New Zealand
Europe
- Austria
- Belgium
- Denmark
- France
- Germany
- Hungary
- Italy
- Lithuania
- Macedonia
- Netherlands
- Poland
- Portugal
- Romania
- Serbia
- Spain
- Sweden
- UK
Middle East
- Israel
- Saudi Arabia
- Turkey
Lung Function Improvement After Bronchoscopic Lung Volume Reduction With Pulmonx Endobronchial Valves Used in Treatment of Emphysema
The Pulmonx Zephyr Endobronchial Valve (EBV) is an implantable bronchial valve intended to
decrease volume in targeted regions of the lung. It is indicated for the treatment of
patients with severe emphysema. The EBV are placed in the diseased region of the lung using
bronchoscopy. Bronchoscopy is a way to access the lungs using a small tube with a camera on
the end. As the diseased region of the lung shrinks in size, healthier regions may expand
and function more efficiently, resulting in improved breathing.
The LIBERATE Study is a clinical trial with two groups. Participants are assigned at random
to the 'Treatment' group or to the 'Control' group. The 'Treatment' group will receive the
Zephyr Endobronchial Valve (EBV) in combination with optimal medical therapy. The 'Control'
group will receive optimal medical therapy alone. For every three participants in the study,
two will go into the 'Treatment' group and one will go into the 'Control' group.
It is hypothesized that after placement of the EBV, lung function will be improved as
compared to standard medical therapy alone.
Powered by
SC CTSI