Myocardial infarction: tPA, age over 60, anterior MI, Killip class and diastolic blood pressure affected stroke rates.

Clinical bottom line (level 2b)

  1. About 1% of patients with acute myocardial infarction who are given thrombolysis will have a stroke in hospital.
  2. Patients with myocardial infarction who are given thrombolysis, are at an increased risk of a stroke if they: have tissue plasminogen activator; aged older than 60; have an anterior site MI; Killip class of 2 or more; diastolic blood pressure >110 mmHg.
Maggioni et al: New England Journal of Medicine 1992; 327 (1): 1-6
Expires March 2003

The study

Inception cohort study with objective outcomes, adjusted for confounding factors, not validated in an independent set of patients.

Setting: multicentre, Italy and Belgium

20768 patients (aged ?, ?% male) chest pain with ST-segment elevation of 1 mm or more in any lead of the ECG, 2 mm or more in any precordial lead, or both and admitted to hospital within six hours of symptom onset, and agreed to randomisation between thrombolytic (tPA and streptokinase)

Excluded if
  • contraindication to thrombolytic or antithrombotic treatment



Factors studied:
  • stroke
  • tissue plasmingen activator (versus streptokinase)
  • aged 60-70 years
  • aged >70
  • anterior site of MI
  • Killip class 2 at admission
  • Killip class 3 or 4 at admission
  • diastolic blood pressure >110 mmHg
  • aspirin use


Streptokinase or tissue plasminogen activator.

Multiple logistic regression was used to adjust for confounding factors.

100% followed for in-hospital
Outcomes studied:
  • stroke

The evidence

outcome time to outcome number of patients/total number %
(95% CI)
stroke in-hospital 236/20768 1.14%
(0.99% to 1.28%)

prognostic factor for
stroke 		time to outcome control rate (%) adjusted OR
(95% CI)		 NNF+
(95% CI)
tissue plasmingen activator (versus streptokinase) ? 236/20768
(1.14%) 		1.42
(1.09 to 1.84) 		212
(107 to 987)
aged 60-70 years ? 236/20768
(1.14%) 		1.67
(1.15 to 2.41) 		133
(64 to 593)
aged >70 ? 236/20768
(1.14%) 		2.72
(1.85 to 4.00) 		53
(31 to 105)
anterior site of MI ? 236/20768
(1.14%) 		1.38
(1.06 to 1.79) 		235
(113 to 1480)
Killip class 2 at admission ? 236/20768
(1.14%) 		1.49
(1.10 to 2.03) 		182
(87 to 888)
Killip class 3 or 4 at admission ? 236/20768
(1.14%) 		1.87
(1.14 to 3.09) 		112
(43 to 625)
diastolic blood pressure >110 mmHg ? 236/20768
(1.14%) 		2.88
(1.11 to 7.49) 		48
(15 to 808)
aspirin use ? 50/1949
(2.6%) 		0.44
(0.32 to 0.61) 		-69
(-57 to -115)

Comments

  1. Data was taken from a randomised trial of streptokinase versus tissue plasminogen activator, so all patients were given thrombolysis.
  2. Numbers needed to follow may be over estimated due to an overall control rate for stroke.

Citation

  1. Maggioni AP, Franzosi MG, Santoro E, et al: The risk of stroke in patients with acute myocardial infarction after thrombolytic and antithrombotic treatment. New England Journal of Medicine 1992; 327 (1): 1-6
Contributor: Clare Wotton and Bob Phillips, February 2000
Reviewer:

Clinical Question.
Patient myocardial infarction
Intervention or Exposure presence of prognostic factors
Comparison absence of prognostic factors
Outcome stroke