Objective To assess the accuracy of Global Registry of
Acute Coronary Events (GRACE) scores in predicting
mortality at 6 months for people with chronic obstructive
pulmonary disease (COPD) and to investigate how it
might be improved.
Methods Data were obtained on 481 849 patients
with acute coronary syndrome admitted to UK hospitals
between January 2003 and June 2013 from the
Myocardial Ischaemia National Audit Project (MINAP)
database. We compared risk of death between patients
with COPD and those without COPD at 6 months,
adjusting for predicted risk of death. We then assessed
whether several modifications improved the accuracy of
the GRACE score for people with COPD.
Results The risk of death after adjusting for GRACE
score predicted that risk of death was higher for patients
with COPD than that for other patients (RR 1.29, 95% CI
1.28 to 1.33). Adding smoking into the GRACE score
model did not improve accuracy for patients with COPD.
Either adding COPD into the model (relative risk (RR)
1.00, 0.94 to 1.02) or multiplying the GRACE score by 1.3
resulted in better performance (RR 0.99, 0.96 to 1.01).
Conclusions GRACE scores underestimate risk of death
for people with COPD. A more accurate prediction of risk
of death can be obtained by adding COPD into the GRACE
score equation, or by multiplying the GRACE score
predicted risk of death by 1.3 for people with COPD. This
means that one third of patients with COPD currently
classified as low risk should be classified as moderate risk,
and could be considered for more aggressive early
treatment after non-ST-segment elevation myocardial
infarction or unstable angina