Context Patients with unstable angina or non–ST-segment elevation myocardial
infarction (NSTEMI) can be cared for with a routine invasive strategy involving
coronary angiography and revascularization or more conservatively with a selective
invasive strategy in which only those with recurrent or inducible ischemia
are referred for acute intervention.
Objective To conduct a meta-analysis that compares benefits and risks of routine
invasive vs selective invasive strategies.
Data Sources Randomized controlled trials identified through search of MEDLINE and
the Cochrane databases (1970 through June 2004) and hand searching of cross-references
from original articles and reviews.
Study Selection Trials were included that involved patients with unstable angina or
NSTEMI who received a routine invasive or a selective invasive strategy.
Data Extraction Major outcomes of death and myocardial infarction (MI) occurring from
initial hospitalization to the end of follow-up were extracted from published
results of eligible trials.
Data Synthesis A total of 7 trials (N = 9212 patients) were eligible. Overall,
death or MI was reduced from 663 (14.4%) of 4604 patients in the selective
invasive group to 561 (12.2%) of 4608 patients in the routine invasive group
(odds ratio [OR], 0.82; 95% confidence interval [CI], 0.72-0.93; P = .001). There was a nonsignificant trend toward fewer
deaths (6.0% vs 5.5%; OR, 0.92; 95% CI, 0.77-1.09; P = .33)
and a significant reduction in MI alone (9.4% vs 7.3%; OR, 0.75; 95% CI, 0.65-0.88; P<.001). Higher-risk patients with elevated cardiac
biomarker levels at baseline benefited more from routine intervention, with
no significant benefit observed in lower-risk patients with negative baseline
marker levels. During the initial hospitalization, a routine invasive strategy
was associated with a significantly higher early mortality (1.1% vs 1.8% for
selective vs routine, respectively; OR, 1.60; 95% CI, 1.14-2.25; P = .007) and the composite of death or MI (3.8% vs 5.2%;
OR, 1.36; 95% CI, 1.12-1.66; P = .002).
But after discharge, the routine invasive strategy was associated with fewer
subsequent deaths (4.9% vs 3.8%; OR, 0.76; 95% CI, 0.62-0.94; P = .01) and the composite of death or MI (11.0% vs 7.4%;
OR, 0.64; 95% CI, 0.56-0.75; P<.001). At the end
of follow-up, there was a 33% reduction in severe angina (14.0% vs 11.2%;
OR, 0.77; 95% CI, 0.68-0.87; P<.001) and a 34%
reduction in rehospitalization (41.3% vs 32.5%; OR, 0.66; 95% CI, 0.60-0.72; P<.001) with a routine invasive strategy.
Conclusions A routine invasive strategy exceeded a selective invasive strategy in
reducing MI, severe angina, and rehospitalization over a mean follow-up of
17 months. But routine intervention was associated with a higher early mortality
hazard and a trend toward a mortality reduction at follow-up. Future strategies
should explore ways to minimize the early hazard and enhance later benefits
by focusing on higher-risk patients and optimizing timing of intervention
and use of proven therapies.