The Manchester Acute Coronary Syndromes (MACS) decision rule for suspected cardiac chest pain: derivation and external validation.
OBJECTIVE
We aimed to derive and validate a clinical decision rule (CDR) for suspected cardiac chest pain in the emergency department (ED). Incorporating information available at the time of first presentation, this CDR would effectively risk-stratify patients and immediately identify: (A) patients for whom hospitalisation may be safely avoided; and (B) high-risk patients, facilitating judicious use of resources.


METHODS
In two sequential prospective observational cohort studies at heterogeneous centres, we included ED patients with suspected cardiac chest pain. We recorded clinical features and drew blood on arrival. The primary outcome was major adverse cardiac events (MACE) (death, prevalent or incident acute myocardial infarction, coronary revascularisation or new coronary stenosis >50%) within 30 days. The CDR was derived by logistic regression, considering reliable (κ>0.6) univariate predictors (p<0.05) for inclusion.


RESULTS
In the derivation study (n=698) we derived a CDR including eight variables (high sensitivity troponin T; heart-type fatty acid binding protein; ECG ischaemia; diaphoresis observed; vomiting; pain radiation to right arm/shoulder; worsening angina; hypotension), which had a C-statistic of 0.95 (95% CI 0.93 to 0.97) implying near perfect diagnostic performance. On external validation (n=463) the CDR identified 27.0% of patients as 'very low risk' and potentially suitable for discharge from the ED. 0.0% of these patients had prevalent acute myocardial infarction and 1.6% developed MACE (n=2; both coronary stenoses without revascularisation). 9.9% of patients were classified as 'high-risk', 95.7% of whom developed MACE.


CONCLUSIONS
The Manchester Acute Coronary Syndromes (MACS) rule has the potential to safely reduce unnecessary hospital admissions and facilitate judicious use of high dependency resources.
Cardiovascular Sciences Research Group, The University of Manchester, Manchester, UK Emergency Department, Central Manchester University Hospitals Foundation NHS Trust, Manchester, UK.
Richard
R
Body
Emergency Department, Central Manchester University Hospitals Foundation NHS Trust, Manchester, UK Department of Health & Social Care, Manchester Metropolitan University, Manchester, UK.
Simon
S
Carley
Cardiovascular Sciences Research Group, The University of Manchester, Manchester, UK.
Garry
G
McDowell
Emergency Department, Central Manchester University Hospitals Foundation NHS Trust, Manchester, UK.
Philip
P
Pemberton
Biochemistry Department, Stockport Hospital, Stockport NHS Foundation Trust, Stockport, UK.
Gillian
G
Burrows
Department of Epidemiology, Stockport Hospital, Stockport NHS Foundation Trust, Stockport, UK.
Gary
G
Cook
Cardiology Department, Stockport Hospital, Stockport NHS Foundation Trust, Stockport, UK.
Philip S
PS
Lewis
Emergency Department, Central Manchester University Hospitals Foundation NHS Trust, Manchester, UK.
Alexander
A
Smith
Emergency Department, Central Manchester University Hospitals Foundation NHS Trust, Manchester, UK Department of Health & Social Care, Manchester Metropolitan University, Manchester, UK.
Kevin
K
Mackway-Jones
D054058:Acute Coronary Syndrome / Q000097:blood / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D003661:Decision Support Techniques; D004636:Emergency Service, Hospital; D004739:England / Q000453:epidemiology; D006760:Hospitalization; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality / Q000628:therapy; D009204:Myocardial Revascularization; D010351:Patient Discharge; D018579:Patient Selection; D011237:Predictive Value of Tests; D015995:Prevalence; D011379:Prognosis; D011446:Prospective Studies; D015203:Reproducibility of Results; D018570:Risk Assessment; D012307:Risk Factors; D019564:Unnecessary Procedures
D015415:Biomarkers