TIMI Risk Index for Triaging Patients with ST-Elevation Acute Myocardial Infarction

 

Patient selection: Patients were enrolled within 6 hours of symptom onset.

 

Patient exclusion criteria: any history of cerebrovascular disease, systolic blood pressure > 180 mm Hg, diastolic blood pressure > 110 mm Hg, cardiogenic shock, or increased risk of severe bleeding.

 

Parameters:

(1) age in years (mortality increases with age)

(2) heart rate in beats per minute (mortality increases with heart rate)

(3) systolic blood pressure in mm Hg (mortality higher with low blood pressures)

 

risk index =

= (heart rate) * (((age) / 10)^2) / (systolic blood pressure) =

= (heart rate) * ((age)^2) / (100 * (systolic blood pressure)

Risk Index	Risk Group	24 Hour Mortality Rate	In-Hospital Mortality Rate	30 Days Mortality Rate
<= 12.5	1	0.2%	0.6%	0.8%
12.51 – 17.5	2	0.4%	1.5%	1.9%
17.51 – 22.5	3	1.0%	3.1%	3.3%
22.51 – 30.0	4	2.4%	6.5%	7.3%
> 30	5	6.9%	15.8%	17.4%

from page 1574

 

Performance:

• In an external validation with patients from the TIMI 9 trials, the index showed high discriminatory capacity (c statistic 0.79) and concordance between observed 30 day mortality and predicted rates (goodness of fit, p = 0.7).