What have the new definition of acute myocardial infarction and the introduction of troponin measurement done to the coronary care unit? Impacts on admission rate, length of stay, case mix and mortality.
OBJECTIVE
To assess the impact of the new American College of Cardiology/European Society of Cardiology definition of acute myocardial infarction (AMI) and the introduction of troponin measurement on the coronary care unit (CCU).


METHODS
This was a retrospective cohort study performed in a tertiary care university hospital. All admissions to the CCU during the year before (period 1, year 2000, n = 1,134) and the year after (period 2, year 2002, n = 1,360) the introduction of troponin measurement and the new AMI definition were studied. We studied baseline characteristics, case load, distribution of admission diagnoses, management and outcome of patients in the two periods.


RESULTS
There was a 20% increase in the number of CCU admissions, driven solely by a 141% increase in the burden of non-ST elevation AMI (NSTEMI) (p < 0.01). This increase was not a mere reflection of a change in diagnostic criteria, as the overall burden of non-ST elevation acute coronary syndromes (ACS) (NSTEMI + unstable angina) increased by 46%, suggesting referral of many more patients to the CCU. Despite a 42% increase in the number of angiograms performed, the proportion of ACS patients who had an angiogram declined. AMI patients in period 2 were older and had higher rates of coronary risk factors but had a higher chance of receiving a guideline-based therapy. Length of CCU stay decreased by a whole day for all ACS patients. 30-day mortality for AMI patients did not change significantly.


CONCLUSIONS
The new AMI definition had a dramatic impact on the CCU case load, case mix and length of stay and on the ability to provide early coronary angiography.
Amit
Guy
G
Department of Cardiology, Soroka Medical Center, Faculty of Health Sciences, Ben Gurion University, Beer-Sheva, Israel.
Gilutz
Harel
H
Cafri
Carlos
C
Wolak
Arik
A
Ilia
Reuben
R
Zahger
Doron
D
D000368:Aged; D000789:Angina, Unstable / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy; D017023:Coronary Angiography / Q000706:statistics & numerical data; D003325:Coronary Care Units / Q000706:statistics & numerical data*; D005260:Female; D006785:Hospitals, University / Q000706:statistics & numerical data; D006801:Humans; D007557:Israel / Q000453:epidemiology; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology / Q000628:therapy*; D010343:Patient Admission / Q000706:statistics & numerical data; D012189:Retrospective Studies; D014336:Troponin / Q000097:blood*; D016526:Workload / Q000706:statistics & numerical data
D014336:Troponin