Background and purpose Variability in response to the P2Y12 receptor antagonists administered to patients with cerebral aneurysms treated with the Pipeline Embolization device (PED) or stents may play an important role in post-operative thromboembolic and haemorrhagic complications. We present our initial institutional experience using a target P2Y12 reaction units (PRU) range to tailor the clopidogrel dose administered.
Methods We retrospectively reviewed all patients who underwent endovascular treatment of cerebral aneurysms with the PED or stent-assistance at our institution from November 15th, 2011 until December 31st, 2013. Patient characteristics, P2Y12 receptor antagonist administered, thromboembolic and haemorrhagic complications, and clinical outcomes using the modified Rankin Scale (mRS) were recorded. The target PRU range was 60–240.
Results Sixty-six patients were included, 49 females (74%) and 17 males (26%), mean age 57.5 years (25–82 years). Forty-six patients were treated with the PED (70%), 19 with a stent (29%) and 1 with a PED and a stent (1%). Eight patients were switched to prasugrel due to an initial clopidogrel hypo-response (12.1%). Forty patients underwent at least 1 adjustment to the clopidogrel dose due to either a hypo-response (PRU > 240) or hyper-response (PRU < 60) to the standard 75mg daily clopidogrel dose (61%), occurring on average 23 days after initiation of clopidogrel therapy. Among these, the first adjustment was made on average 8.5 days before the procedure in 13 patients (32.5%), on the day of the procedure in 6 patients (15%), and on average 23.7 days after the procedure in 21 patients (52.5%). After the first dose adjustment, the target 60–240 PRU range was reached in 71% of hypo-responders and 46% of hyper-responders. Table 1 illustrates the PRU change after the first clopidogrel dose adjustment. Table 2 illustrates the PRU change after subsequent clopidogrel dose adjustments. Table 3 illustrates the final P2Y12 receptor antagonist administered and associated thromboembolic and haemorrhagic complications leading to a permanent disabling neurological deficit (mRS ≥ 3).
Conclusion Overall, 73% of patients with cerebral aneurysms treated with the PED or stents required at least 1 adjustment to the clopidogrel dose or a switch to an alternate P2Y12 receptor antagonist to remain within the target 60–240 PRU range.
Disclosures J. Delgado Almandoz: 2; C; Covidien/ev3, Microvention/Terumo, Penumbra Inc. Y. Kadkhodayan: 2; C; Covidien/ev3. J. Scholz: None. J. Fease: None. A. Blem: None. K. Tran: None. B. Crandall: 2; C; Covidien/ev3.