Platelet Testing is Associated with Worse Clinical Outcomes for Patients Treated with the Pipeline Embolization Device

BACKGROUND AND PURPOSE: The necessity for platelet-inhibition testing before aneurysm treatment in patients premedicated with antiplatelet agents is controversial. Using the International Retrospective Study of Pipeline Embolization Device registry, we studied complication rates in groups of patients who underwent platelet testing and those who did not undergo platelet testing to determine if these test results were associated with improved outcomes. MATERIALS AND METHODS: Patients in the International Retrospective Study of Pipeline Embolization Device registry with an unruptured aneurysm were categorized as those who underwent platelet testing before Pipeline embolization device treatment or those who did not. Complication rates were compared by using the Fisher exact or Pearson χ(2) test. Multivariate analysis was performed to determine if platelet function testing was independently associated with poor outcomes after adjusting for age, number of devices and aneurysms, aneurysm location and size, and practitioner and center volume. RESULTS: Compared with the patients who received a Pipeline embolization device without platelet testing, those who underwent platelet testing and Pipeline embolization device placement experienced higher rates of intracranial hemorrhage (0 of 187 [0.0%] vs 12 of 511 [2.3%], respectively; P = .04), neurologic morbidity (4 of 187 [2.1%] vs 42 of 511 [8.2%], respectively; P < .01), and combined neurologic morbidity and mortality (6 of 187 [3.2%] vs 45 of 511 [8.8%], respectively; P = .01). More patients in the platelet testing and Pipeline embolization device group were treated with multiple devices (227 [38.0%] vs 56 [27.8] patients, respectively; P = .01). On multivariate analysis, the group of patients who underwent platelet testing and Pipeline embolization device placement had higher odds of neurologic morbidity (OR, 3.25 [95% CI, 1.10-9.61]; P = .03). CONCLUSIONS: Platelet testing in patients who undergo Pipeline embolization device placement is associated with higher rates of morbidity. Additional prospective studies are needed to determine if and when platelet testing in these patients is appropriate.