Long-term outcomes after first-ever posterior circulation stroke and the prognostic significance of the New England Medical Center Posterior Circulation Registry stroke classification: A prospective study from the Athens Stroke Registry

Background: There is paucity of data on the long-term outcomes after acute ischemic posterior circulation stroke (PCS). Additionally, the long-term prognostic value of the New England Medical Center-Posterior Circulation Registry (NEMC-PCR) classification of PCS has not been studied.

Patients and methods: All consecutive patients with PCS registered in the Athens Stroke Registry between 01/1993 and 12/2012 were prospectively followed for up to 10 years and included in the analysis. The NEMC-PCR criteria were applied to classify them in relation to topography. The main studied outcomes were all cause mortality, stroke recurrence and major adverse cardiovascular events (MACEs).

Results: A total of 653 patients with PCS (455 men, mean age 68.06 years) were followed up for 52.8 ± 44.0 months. Seventy-four (11.3%), 219 (33.5%), 335 (51.3%), and 25 (3.8%) patients had proximal, middle, distal, and multiple territories PCS, respectively. During the 10-year follow-up period, 217 patients died (7.6 per 100 patient years), 127 developed recurrent stroke (4.2 per 100 patient years), and 209 had a MACE (7.3 per 100 patient years). The cumulative 10-year mortality was higher in distal and multiple territories PCS compared to middle and proximal PCS (55.6%, 58.8%, 40.0%, 35.5%, respectively, p < 0.001 by log-rank test). Patients with distal location PCS had almost twofold increased 10-year risk of mortality compared to proximal location patients after adjusting for all confounding variables (HR 1.99, 95% CI 1.05-3.77). Per TOAST classification, large artery atherosclerosis was associated with almost two-fold increase in risk of mortality, stroke recurrence and MACEs.

Discussion and conclusion: A large proportion of PCS patients experienced 10-year death, stroke and MACE occurrence after PCS. NEMC-PCR topographic classification was found to have significant prognostic value, with distal and middle PCS having worse long-term outcomes than proximal PCS.