VIEWS & REVIEWS

Late thrombolysis - why draw

the line at 12 hours?

-Gill Higgins-

Possibly one of the most important lessons arising from the Late Assessment of Thrombolytic Efficacy (LATE) study concerns the appropriateness of arbitrary limits imposed upon therapeutic decision-making. Previously, it was considered that patients presenting > 6 hours after the onset of MI symptoms should not be given thrombolytic therapy. Now, following presentation of the LATE study results at the XIVth Congress of the European Society of Cardiology, it is apparent that mortality is reduced by nearly 30% if therapy is received after this time.

However, it is likely that the new data will lead hospitals to reset their embargoes on thrombolytic use to 12 hours. Although in the LATE study no significant reduction in mortality was seen in the group of patients presenting > 12 hours after onset, a 5% trend towards reduction was seen. This brings into question the usefulness of time as an independent factor and warrants investigation into other measures that may better represent a patient's condition.

Dr R Wilcox from Nottingham, UK, one of the principal LATE study investigators, commented that subgroup analyses were underway that could help to identify the pertinent factors in determining whether thrombolysis is appropriate. These could include: • presence of continuing pain • ST segment elevation • administration of adjacent heparin • gender.

Identification of the appropriate factors could also prevent the unnecessary exposure of patients with a fully established MI to the risks associated with thrombolytics. However, a foreseeable problem is the practical difficulty encountered by admitting physicians if the patient has to be assessed for several criteria.

[See also Inpharma 854: 17. 12 Sep 1992]. K(1(115n~1

ISSN 0156-2703l9210919-0071$1.00© Adlslntemational Ltd

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