Multiple electrode aggregometry predicts stent thrombosis better than the vasodilator‐stimulated phosphoprotein phosphorylation assay

Abstract

Summary. Background and Aim: The prognostic value of the vasodilator-stimulated phosphoprotein (VASP) phosphorylation assay and multiple electrode aggregometry (MEA) for thrombotic adverse events has been shown in independent studies. As no direct comparison between the two methods has been made so far, we investigated which laboratory approach has a better predictive value for stent thrombosis. Methods: The VASP phosphorylation assay and MEA were performed in 416 patients with coronary artery disease undergoing percutaneous coronary intervention. The rate of stent thrombosis was recorded during a 6-month follow-up. Results: Definite stent thrombosis occurred in three patients (0.7%) and probable stent thrombosis in four (1%). Receiver operating characteristic (ROC) analysis demonstrated that MEA distinguishes between patients with or without subsequent stent thrombosis better than the VASP phosphorylation assay: the area under the ROC curve was higher for MEA (0.92; P = 0.012) than for the VASP phosphorylation assay (0.60; P = 0.55). At equal levels of sensitivity (100%), the specificity was greater for MEA than for the VASP phosphorylation assay (86% vs. 37%). Stent thrombosis occurred in 9% of patients with platelet hyperreactivity in MEA, who were simultaneously clopidogrel nonresponders in the VASP phosphorylation assay. Interestingly, clopidogrel non-responders in the VASP phosphorylation assay without platelet hyperreactivity in MEA did not suffer from stent thrombosis. Conclusions: Platelet hyperreactivity in MEA might be a better risk predictor for stent thrombosis than the assessment of the specific clopidogrel effect with the VASP phosphorylation assay.

Multiple electrode aggregometry and vasodilator stimulated phosphoprotein-phosphorylation assay in clinical routine for prediction of postprocedural major adverse cardiovascular events

“…However, knowledge of the predictive value of the VASP-P assay in high-risk STEMI patients is missing except for one recent publication which outlined that the VASP-P assay might be helpful in predicting cardiovascular death above a cut-off of PRI=61% in unselected patients (43). The high sensitivity (93.8%) as well as the low specificity (39.8%) of the VASP-P assay in our study is comparable with earlier findings (8,11). It has recently been shown that levels of P2Y 12 -blockade above 60% are required to block the effects of ADP on PGE 1 -induced phosphorylation of VASP (44).…”

“…However, previous studies have shown that MEA is predictive for stent thrombosis and death in patients with planned DES implantation (9,39). Others showed that MEA predicts stent thrombosis better than the VASP-P assay (8). Interestingly, the conclusion of the latter study was mainly based on ROC curves from three definite stent thromboses.…”

“…high ontreatment platelet reactivity (HTPR), has been called to account repeatedly (5,6). HTPR after short-term therapy apparently is associated with an increased cardiovascular risk ranging from a modest increase up to odds ratios (OR) of 8, depending on the patient population and test systems studied (7)(8)(9)(10)(11)(12)(13).…”

Consensus recommendations for using the Multiplate® for platelet function monitoring before cardiac surgery

“…Antiplatelet drugs differ in their pharmacokinetic and pharmacodynamic characteristics. Current guidelines recommend stopping antiplatelet drugs 3 to 7 days before surgery [8][9][10], however a proportion of individuals are 'resistant' to aspirin or the P2Y 12 antagonist or both [11][12][13]. The Society of Thoracic Surgeons Clinical Practice Guidelines (updated in 2012) states: "for patients on dual antiplatelet therapy, it is reasonable to make decisions about surgical delay based on tests of platelet inhibition rather than arbitrary use of a specified period of surgical delay" [14].…”

Prasugrel overcomes high on-clopidogrel platelet reactivity in the acute phase of acute coronary syndrome and maintains its antiplatelet potency at 30-day follow-up

“…To strengthen our findings we also applied in the calculations other clinically validated HTPR definitions (PRI > 60% [16,17] and AUC > 54 U [18] for VASP and MEA, respectively).…”