Long-term prognosis after transient ischemic attacks

A retrospective follow-up study of 243 patients with transient ischemic attacks (TIA) is reported. The long-term mortality of the patients was higher than that of the corresponding general population. It is demonstrated that the excess mortality over the whole period of observation, irrespective of the age and sex of the patients, can be characterized by a single figure expressing the slope of the curve obtained by semilogarithmic plotting of the ratios of observed to expected survival against time. The use of this numerical expression--in the present series -0.04--will thus facilitate comparisons of the survival of TIA patients drawn from different populations. Unfavourable prognostic factors were: carotid TIA, associated extracerebral disease, and a history of hypertension. Fatal strokes, being four times as frequent as expected according to published incidence figures, accounted for 20% of the deaths, heart disease 38%. Stroke deaths tended to occur earlier than cardiac deaths. The results support the concept that most TIAs, like strokes, are incidents in the progressive course of a generalized vascular disease. The finding of a constant excess mortality over the years following a TIA makes it difficult to recommend a discontinuation of prophylactic therapy at any particular time.