Optimal medical therapy with or without percutaneous coronary intervention to reduce ischemic burden: results from the Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) trial nuclear substudy.
BACKGROUND
Extent and severity of myocardial ischemia are determinants of risk for patients with coronary artery disease, and ischemia reduction is an important therapeutic goal. The Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) nuclear substudy compared the effectiveness of percutaneous coronary intervention (PCI) for ischemia reduction added to optimal medical therapy (OMT) with the use of myocardial perfusion single photon emission computed tomography (MPS).


RESULTS
Of the 2287 COURAGE patients, 314 were enrolled in this substudy of serial rest/stress MPS performed before treatment and 6 to 18 months (mean=374+/-50 days) after randomization using paired exercise (n=84) or vasodilator stress (n=230). A blinded core laboratory analyzed quantitative MPS measures of percent ischemic myocardium. Moderate to severe ischemia encumbered > or = 10% myocardium. The primary end point was > or = 5% reduction in ischemic myocardium at follow-up. Treatment groups had similar baseline characteristics. At follow-up, the reduction in ischemic myocardium was greater with PCI+OMT (-2.7%; 95% confidence interval, -1.7%, -3.8%) than with OMT (-0.5%; 95% confidence interval, -1.6%, 0.6%; P<0.0001). More PCI+OMT patients exhibited significant ischemia reduction (33% versus 19%; P=0.0004), especially patients with moderate to severe pretreatment ischemia (78% versus 52%; P=0.007). Patients with ischemia reduction had lower unadjusted risk for death or myocardial infarction (P=0.037 [risk-adjusted P=0.26]), particularly if baseline ischemia was moderate to severe (P=0.001 [risk-adjusted P=0.08]). Death or myocardial infarction rates ranged from 0% to 39% for patients with no residual ischemia to > or = 10% residual ischemia on follow-up MPS (P=0.002 [risk-adjusted P=0.09]).


CONCLUSIONS
In COURAGE patients who underwent serial MPS, adding PCI to OMT resulted in greater reduction in ischemia compared with OMT alone. Our findings suggest a treatment target of > or = 5% ischemia reduction with OMT with or without coronary revascularization.
Shaw
Leslee J
LJ
Emory University School of Medicine, Atlanta, GA 30306, USA. leslee.shaw@emory.edu
Berman
Daniel S
DS
Maron
David J
DJ
Mancini
G B John
GB
Hayes
Sean W
SW
Hartigan
Pamela M
PM
Weintraub
William S
WS
O'Rourke
Robert A
RA
Dada
Marcin
M
Spertus
John A
JA
Chaitman
Bernard R
BR
Friedman
John
J
Slomka
Piotr
P
Heller
Gary V
GV
Germano
Guido
G
Gosselin
Gilbert
G
Berger
Peter
P
Kostuk
William J
WJ
Schwartz
Ronald G
RG
Knudtson
Merill
M
Veledar
Emir
E
Bates
Eric R
ER
McCallister
Benjamin
B
Teo
Koon K
KK
Boden
William E
WE
D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D003131:Combined Modality Therapy; D017023:Coronary Angiography; D005080:Exercise Test; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis / Q000188:drug therapy* / Q000628:therapy*; D009204:Myocardial Revascularization / Q000379:methods; D016016:Proportional Hazards Models; D016037:Single-Blind Method; D015899:Tomography, Emission-Computed, Single-Photon; D016896:Treatment Outcome