Determinants of Survival in Patients with Vertebrobasilar Diseases

Abstract & Commentary

Source: Qureshi AI, et al. Stroke-free survival and its determinants in patients with symptomatic vertebrobasilar stenosis: A multicenter study. Neurosurgery. 2003;52:1033-1040.

Intracranial balloon angioplasty and stent placement now are available to patients suffering from intracranial stenosis that involves the vertebrobasilar arteries (VBA). At present, however, no consensus exists regarding the role of endovascular procedures vs best medical management. Accordingly, it is imperative to know the natural history of patients affected with posterior circulation intracranial stenosis in order to determine whether the benefit of endovascular treatment outweighs the risks.

Qureshi and colleagues performed a multicenter retrospective study to identify the long-term stroke-free survival of medically treated patients who presented with TIA or stroke related to intracranial VBA stenosis. VBA stenosis was diagnosed on the basis of magnetic resonance angiography and/or conventional angiography.

A total of 102 patients (55 men and 47 women) with TIA (n = 30) or ischemic stroke (n = 72) were included. Their mean age was 64 ± 12 years. The mean period of follow-up was 15 months (range, 1-60 months). During the follow-up period, 14 patients suffered recurrent strokes and 21 died. Sixteen of the deaths were related to initial or recurrent strokes. Stroke-free survival was 76% at 12 months and 48% at 5 years. The risk of recurrent stroke was 11% per year, and the rate of recurrent stroke and/or death was 24% per year. The high mortality probably was due to the severe neurological deficits associated with brainstem strokes that led to fatal complications such as pneumonia and sepsis. Older patients had a decreased stroke-free survival. Treatment with either antiplatelet agents in 41% or warfarin in 32% improved stroke-free survival.

Qureshi et al concluded from these results that further studies are needed to evaluate medical and endovascular treatment options for this group of patients with a poor prognosis for stroke-free survival.

Commentary

The 11% annual stroke recurrence rate found by Qureshi et al compares to that reported by the Warfarin-Aspirin for Symptomatic Intracranial Disease (WASID) study group.1 The WASID investigators studied 59 patients with 50-99% stenosis involving the VBA. Stroke rates in the same territory as the stenotic artery were 11% in patients with basilar artery stenosis and 8% in patients with vertebral artery stenosis. A prospective, randomized study by the WASID investigators has now undertaken to compare the efficacy of aspirin with that of warfarin in preventing recurrent stroke in patients with symptomatic intracranial stenosis.2 The WASID study will provide prospective data on the prognosis of symptomatic intracranial vascular disease in patients treated with either 1300 mg of aspirin daily or warfarin to achieve an INR of between 2 and 3. Nevertheless, the current study emphasizes the need for a randomized comparison of current best medical therapy with the latest endovascular techniques and intracranial stents. It is hoped that such a study will show that endovascular techniques produce not only improved vascular patency and restored blood flow but also greater patient well-being. — John J. Caronna

Dr. Caronna is Vice-Chairman, Department of Neurology, Cornell University Medical Center; Professor of Clinical Neurology, New York Hospital.

References

1. The Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) study group. Stroke. 1998;29:1389-1392.

2. Benesch CG, Chimowitz MI. Neurology. 2000;55: 465-466.