Incidence, outcome, risk factors, and long-term prognosis of cryptogenic transient ischaemic attack and ischaemic stroke: a population-based study.

A third of transient ischaemic attacks (TIAs) and ischaemic strokes are of undetermined cause (ie, cryptogenic), potentially undermining secondary prevention. If these events are due to occult atheroma, the risk-factor profile and coronary prognosis should resemble that of overt large artery events. If they have a cardioembolic cause, the risk of future cardioembolic events should be increased. We aimed to assess the burden, outcome, risk factors, and long-term prognosis of cryptogenic TIA and stroke.