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Page 1: More on thrombolytics in acute myocardial infarction

More on thrombolytics in acute myocardial infarction TIMI II: routine angioplasty and PTeA are not indicated in addition to aheplase therapy

Early thrombolysis is a recognised advance in the management of acute myocardial infarction. Because successful thrombolysis clears the acute occlusion but not any underlying lesion, it has been suggested that early coronary angiography followed, if indicated, by percutaneous transluminal coronary angioplasty (PTCA) may be useful in preventing reinfarction. However, it has been shown in a randomised study involving 3262 patients that early invasive intervention with thrombolysis, angioplasty and PTCA does not improve survival or reinfarction rates compared with thrombolysis alone.

Patients presenting with symptoms suggestive of acute myocardial infarction (subsequently confirmed in 95%), received 'conservative management' with alteplase 150mg or 1 OOmg, lignocaine, heparin and aspirin (n = 1625); angiography and PTCA could be performed if indicated clinically. 1636 patients were assigned to 'invasive management' in which angiography, + PTCA when indicated, was scheduled within 18-48 hours of initiating the pharmacological components of conservative management. 1390 patients were additionally randomised to immediate IV metoprolol and subsequent oral metoprolol or to deferred treatment with oral metoprolol, begun on day 6. • 1.9% of 582 recipients of alteplase 150mg

developed intracranial haemorrhage vs 0.5% of 2952 recipients of alteplase 100mg: the latter dosage is therefore recommended.

• There was a non-significant trend for death and reinfarction at hospital discharge and at week 6 to be greater in invasively managed patients (5.2 and 6.4%, respectively at week 6) than conservatively managed patients (4.7 and 5.8%, respectively).

• When a composite adverse outcome comparison was performed, 172 conservatively managed patients had had death, non-fatal reinfarction, intracranial haemorrhage or coronary artery bypass surgery vs 212 invasively managed patients (p = 0.04).

• Immediate beta blocker therapy was associated with fewer deaths, recurrent infarctions and recurrent ischaemia than deferred beta blocker therapy in both conservative and invasive management recipients. The authors concluded that conservative

management ' ••• ,... much to commend It' as it can be used in hospitals without specialists in angiography and PTCA and it is effective. However, they stressed that facilities for angiography and angioplasty should be made available when clinically indicated by recurrent ischaemia. The TIMI Study Group. Comparison of invasive and conservative strategies after treatment with intravenous tissue plasminogen activator in acute myocardial infarction. Results of the Thrombolysis in Myocardial Infarction (TIMI) phase II trial. New England Journal of Medicine 320: 618· 6Z7,9 Mar 1989 w,

8 INPHARMA- 22 Jut 1989

Little to choose between alteplase and streptokinase

'A major unre.oIved Issue In the treatment of patlent. with acute mrocatdle"nterctlon I. whether one thrombolytic agent I. superior to others.'

It has been previously shown that alteplase is more effective than streptokinase in recanalising coronary arteries. However, left ventricular function is a better indication of long term prognosis and it was shown in a randomised double-blind double­dummy study that there were no apparent differences in mortality, left ventricular ejection fraction at 3 weeks, patency at 3 weeks, incidence of reinfarction or need for invasive intervention between patients administered alteplase 100mg (n = 135) or streptokinase 150,OOOU (135) within 3 (mean 2.5) hours of first acute, Q wave, infarction. Streptokinase is cheaper than alteplase. White HD, Rivers JT, MaSlowski AH, Ormiston JA, Takayam M, et al. Ellact of intravenous streptokinase as compared with that of tissue plasminogen activator on left ventricular function after first myocardial infarction. New England Journal of MediCine 320: 817·821, 30 Mar 1989

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0156-2703IB910722'()()OBIO$01.0010 @ ADtS Press

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