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Interpretation of IST and CAST stroke trials

1997; Elsevier BV; Volume: 350; Issue: 9075 Linguagem: Inglês

10.1016/s0140-6736(05)64163-3

1474-547X

Stefano Ricci, Teresa Anna Cantisani, Maria Grazia Celani, Enrico Righetti,

Stroke Rehabilitation and Recovery

As members of the Centro di Coordinamento IST-Italia we were involved in discussions on the design and results of IST. We told the writing committee that we would have preferred a more straightforward conclusion on heparin ("There is no clear indication to its use, even at low doses, if the patients can tolerate aspirin"). The final version was a compromise but we still think that the position on heparin was a "soft" one. However, we were surprised that in her commentary (May 31, p 1564)1Bousser M-G Aspirin or heparin immediately after a stroke?.Lancet. 1997; 349: 1564-1565Summary Full Text Full Text PDF PubMed Scopus (31) Google Scholar Marie-Germains Bousser in effect suggests not applying what IST found for either heparin or aspirin, and wish to focus on what she wrote. It is not true that the effect of aspirin was not significant at 6 months; it was, when the imbalance in stroke severity between the six groups was allowed for. Stating that aspirin is not effective in the acute treatment of ischaemia may be correct, but physicians and patients do not mind about the mechanism if early recurrences are prevented. The preliminary CAST data were widely known: they confirm IST for aspirin and the two trials can be summed because the design was almost the same. The absolute benefit of aspirin is small but has anyone anything better to offer to a stroke patient today? We do not think that real bias will have been introduced in the evaluation of haemorrhagic complications because the analysis is based on symptomatic haemorrhages (ie, the patients had focal neurological symptoms) and not on random repeated CT scans in symptomless patients. Bousser's statement on heparin 5000 U is wrong; figure 5 shows that the benefit is exactly the same as it is for aspirin, and the risk is slightly higher. With these data to hand, who would prefer to inject twice a day instead of giving one tablet? Aspirin plus heparin 5000 U twice daily may be better in the short term but IST data are not conclusive. The only evidence-based recommendation we can make is to start aspirin immediately in all patients; there is no advantage for heparin even in those patients who could have had an embolic stroke (ie, those with atrial fibrillation). Bousser does not comment on the other main message of IST ("there is no room for acute therapeutic anticoagulation [heparin 12500 U] in the acute phase of ischaemic stroke". This message will probably alter clinical practice in many hospitals, at least in Italy.