Myocardial infarction: a clinical prediction guide helped rank patients for the risk of dying

Clinical bottom line (level 2b)

  1. One in fifteen patients who receive thrombolysis for a myocardial infarction were dead within 30 days.
  2. A clinical prediction guide based on presenting clinical features could help rank patients for the risk of dying at 30 days.
Morrow et al: Circulation 2000; 102 : 2031-2037
Expires February 2004

The study

Retrospective cohort study with objective outcomes, adjusted for confounding factors, validated in an independent set of patients.

Setting: 800 hospitals, worldwide

15060 patients (aged , % male) with chest pain and ST elevation or LBBB

Excluded if
  • cardiogenic shock
  • increased risk of severe bleeding
  • aged < 18
  • history of cerebrovascular disease
  • systolic bp > 180 mmHg, or diastolic bp > 110 mmHg

Patients were part of a randomised controlled trial receigin therapy with aspirin, heparin and either the bolus fibrinolytic alteplase or lanoteplase.

Multivariate regression analysis was used to identify independent factors associated with mortality.

99.9% followed for 30 days
Outcomes studied:
  • death
  • score > 8
  • 8
  • 7
  • 6
  • 5
  • 4
  • 3
  • 2
  • 1
  • 0

Clinical prediction rule - sum the scores based on clinical features at presentation

  • age 65-74: 2
  • age 75 or over: 3
  • angina, diabetes or hypertension: 1
  • systolic bp < 100: 3
  • heart rate > 100: 2
  • Killip class II-IV: 2
  • weight < 67 kg: 1
  • anterior ST elevation or LBBB: 1
  • time to treatment > 4 hours

The evidence

outcome time to outcome number of patients/total number %
(95% CI)		 NNF
(95% CI)
death 30 days 1009/15060 6.7%
(6.3% to 7.1%)		 15
(14 to 16)
score > 8 30 days 54/151 36%
(28% to 43%)		 3
(2 to 4)
8 30 days 81/301 27%
(22% to 32%)		 4
(3 to 4)
7 30 days 106/106 24%
(20% to 27%)		 4
(4 to 5)
6 30 days 146/904 16%
(14% to 19%)		 6
(5 to 7)
5 30 days 168/1355 12%
(11% to 14%)		 8
(7 to 9)
4 30 days 154/2108 7.3%
(6.2% to 8.4%)		 14
(12 to 16)
3 30 days 106/2304 4.6%
(3.8% to 5.5%)		 22
(18 to 27)
2 30 days 53/2410 2.2%
(1.6% to 2.8%)		 45
(36 to 62)
1 30 days 53/3260 1.6%
(1.2% to 2.1%)		 62
(49 to 84)
0 30 days 14/1807 0.77%
(0.37% to 1.2%)		 130
(85 to 270)

Comments
  1. This clinical prediction rule was only validated using TIMI trial databases.
  2. The study only reported percentages - consequently totals may not add up to 15060.
 

Citation

  1. Morrow DA, Antman EM, Charlesworth A, et al: TIMI risk score for ST-elevation myocardial infarction: a convenient, bedside, clinical score for risk assessment at presentation. An intravenous nPA for treatment of infarction myocardium early II trial substudy. Circulation 2000; 102 : 2031-2037
Search Terms: from ACP Journal Club other articles noted
Contributor: Chris Ball, February 2002
Reviewer:

Clinical Question.
Patient myocardial infarction
Intervention or Exposure clinical features on presentation
Outcome death