Thrombocytopenia and declines in platelet counts: predictors of mortality and outcome after mechanical thrombectomy

Acute ischemic stroke (AIS) has well-known risk factors. The role of platelets in patients treated using mechanical thrombectomy (MT) has not been studied. The aim of this study was to study if there is an association of initial thrombocytopenia (TP) and a decline of platelets counts (DPC) with the clinical outcomes, mortality and intracranial hemorrhage (ICH) rates in AIS patients treated with MT.

In a case-control study consecutive MT-stroke patients were analyzed. A multivariate logistic regression model was used to test for good clinical outcome (mRS 90 days <= 2) and mortality adjusting for age, initial NIHSS, pretreatment with tPA, statins and platelet inhibitors, occlusion site, time from symptom onset to recanalization, initial TP (< 150 × 10⁹/L) and DPC (> 26%). Additionally, rates of ICH were compared.

Of 294 patients included, 9.6% had an initial TP and 23.8% a DPC > 26%. The mortality rate in patients with normal platelet counts was 26.1% vs. 48.3% (p = 0.002) in patients with initial TP with an aOR of 3.47 (CI 1.28-9.4, p = 0.005). No difference regarding the rate of good clinical outcome (p = 0.204) and ICH (p = 0.18) was observed. A DPC of more than 26% during the first 5 days of hospitalization predicted the rate of mortality (aOR 2.4 CI 1.14-5.04, p = 0.021) and the chances of a good clinical outcome (aOR 0.291 CI 0.128-0.666, p = 0.003) without significant differences of ICH rates (p = 0.735).

In AIS patients treated with MT an initial TP was independently associated with higher mortality rates and a marked DPC with higher mortality rates as well as poorer clinical outcomes.