Acute ischaemic stroke outcomes following mechanical thrombectomy in the elderly versus their younger counterpart: a retrospective cohort study

Abstract

Objectives: Many physicians debate the efficacy of mechanical thrombectomy for ischaemic stroke, but most agree that to establish potential benefit, patient selection must be examined further. People >80 years are a growing population of patients with ischaemic stroke but are largely excluded from clinical trials. The benefit of thrombectomy for them may be greatly reduced due to diminishing neuroplasticity and a larger number of medical comorbidities. To address this knowledge gap, we examined clinical and economic outcomes after mechanical thrombectomy in the ischaemic stroke population from the Nationwide Inpatient Sample. Our null hypotheses were that elderly patients (>80 years) would have a similar rate of inpatient mortality in comparison to their younger counterparts and incur a similar economic expense.

Design: Retrospective cohort study.

Setting: A 20% stratified sample of US community hospitals within the Nationwide Inpatient Sample.

Participants: All patients from 2008 to 2010 with a primary diagnosis of ischaemic stroke that received mechanical thrombectomy were included.

Primary and secondary outcome measures: The primary outcome was inpatient mortality. Secondary outcomes included hospital charges and length of stay.

Results: Less than 1% of all ischaemic stroke cases (9300) were treated with mechanical thrombectomy. Of these, 18% involved patients over 80 years of age. The odds of inpatient mortality in elderly patients treated with mechanical thrombectomy were approximately twice that of their younger counterparts (OR1.993, p < 0.001). The elderly experienced no significant difference in hospital charges (p=0.105) and length of stay (p=0.498).

Conclusions: The odds of inpatient mortality after mechanical thrombectomy in patients over 80 years of age were twice that of their younger counterparts. This is consistent with the overall worse prognosis seen in the natural history of this age group. Studies to better identify patients that would benefit from endovascular mechanical thrombectomy may improve outcomes and reduce the gap currently observed in age stratifications.

Keywords: Health Economics; Vascular Surgery.

Figure 1

Multivariate analysis of inpatient mortality and economic measures for survivors. Inpatient mortality expressed as the OR along with the 95% CI derived from binary logistic regression. Length of stay and charges are both expressed using the exponential parameter estimate along with the 95% CI derived from generalised estimating equations. p Values are adjacent to the 95% CIs. Points to the right of 1.0 reflect an increase in the odds/effect ratio relative to the indicated reference category. Points to the left of 1.0 reflect a decrease in the odds/effect ratio relative to the indicated reference category.