Coronary revascularization surgery after myocardial infarction: impact of bypass surgery on survival after thrombolysis. GUSTO Investigators. Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries.
OBJECTIVE
This study sought to investigate the impact of surgical revascularization on outcome after myocardial infarction.


BACKGROUND
Small variations in rates of coronary artery bypass graft surgery (CABG) were noted among thrombolytic regimens in the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO) trial, prompting the question of whether survival differences were partly related to differences in CABG rates.


METHODS
Patients in the GUSTO trial were randomized to one of four thrombolytic strategies. Of 40,861 patients with complete data, 3,526 underwent surgical revascularization during their initial hospital admission. Thirty-day and 1-year mortality rates were estimated using Kaplan-Meier techniques, and the impact of CABG as a time-dependent covariate on death was evaluated using a Cox survival model, adjusting for baseline prognostic factors.


RESULTS
The median time from study enrollment to CABG was 7 days across treatment groups. A 15% reduction in mortality for the tissue-type plasminogen activator (t-PA)-treated group was evident by the seventh day. Bypass surgery was a significant independent predictor of 30-day mortality (risk ratio 1.87) and a weaker predictor of 1-year mortality (risk ratio 1.21). Operative mortality was highest in patients with acute mitral regurgitation, ventricular septal defect or poor left ventricular function and in those undergoing CABG within the first 4 days of randomization.


CONCLUSIONS
The survival benefit of accelerated t-PA was not related to surgical revascularization. Bypass surgery was associated with excess mortality in the first year, but the added short-term mortality associated with CABG may be balanced by anticipated long-term benefit in specific groups of patients.
Tardiff
B E
BE
Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA.
Califf
R M
RM
Morris
D
D
Bates
E
E
Woodlief
L H
LH
Lee
K L
KL
Green
C
C
Rutsch
W
W
Betriu
A
A
Aylward
P E
PE
Topol
E J
EJ
D000368:Aged; D017023:Coronary Angiography; D001026:Coronary Artery Bypass; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use; D006493:Heparin / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000188:drug therapy / Q000401:mortality* / Q000601:surgery*; D011379:Prognosis; D016016:Proportional Hazards Models; D013300:Streptokinase / Q000627:therapeutic use; D015996:Survival Rate; D015912:Thrombolytic Therapy; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use
D005343:Fibrinolytic Agents; D006493:Heparin; D013300:Streptokinase; D010959:Tissue Plasminogen Activator