Comparing risks of death and recurrent vascular events between lacunar and non-lacunar infarction

Differences in prognosis of lacunar and non-lacunar infarction patients might support distinct arterial pathological processes underlying these two subtypes of ischaemic stroke. We performed a systematic review in which we identified cohort studies with ischaemic stroke subtype-specific follow-up data on death, recurrent stroke and/or myocardial infarction (MI). We calculated risks of death and recurrent stroke at 1 month, 1-12 months and 1-5 years, as well as risks of MI and cardiac death. We compared non-lacunar with lacunar infarction, using study-specific and summary odds ratios. We also compared the pattern of recurrent stroke subtypes after lacunar and non-lacunar infarction. One month odds of death and of recurrent stroke were significantly greater following non-lacunar than lacunar infarction, but the difference decreased thereafter (1 month mortality: OR 3.81, 95% CI 2.77-5.23; 1-12 month mortality: OR 2.32, 95% CI 1.74-3.08; 1-5 year mortality: OR 1.77, 95% CI 1.28-2.45; 1 month stroke recurrence: OR 2.11, 95% CI 1.20-3.69; 1-12 month stroke recurrence: OR 1.24, 95% CI 0.85-1.83; 1-5 year stroke recurrence: OR 1.61, 95% CI 0.96-2.70). Recurrent strokes were more likely to be lacunar if the index event was lacunar. Few studies reported on the risk of MI, but we found no significant difference in risk of cardiac death in non-lacunar versus lacunar infarction. Thus, although early mortality and stroke recurrence risks are higher among non-lacunar than lacunar infarct patients, the risks appear not to differ in the longer term and the risks of cardiac outcomes are similar, although data are limited. There is some evidence that recurrent ischaemic stroke subtypes breed true. These results provide limited support for a distinct arterial pathology underlying lacunar infarction.