A Sticky Situation: Variable Agreement Between Platelet Function Tests Used to Assess Anti-platelet Therapy Response

Guided Anti-P2Y12 Therapy in Patients Undergoing PCI: Three Systematic Reviews with Meta-analyses of Randomized Controlled Trials with Homogeneous Design

BACKGROUND

 The value of guided therapy (GT) with anti-P2Y12 drugs in percutaneous coronary intervention (PCI) is unclear. Meta-analyses lumped together randomized controlled trials (RCTs) with heterogeneous designs, comparing either genotype-GT or platelet function test (PFT)-GT with unguided therapy. Some meta-analysis also included RCTs that did not explore GT, but included the effects of switching patients with high on-treatment platelet reactivity (HTPR) to alternative therapies (HTPR-Therapy). We performed three distinct systematic reviews/meta-analyses, each exploring only RCTs with homogeneous design.

METHODS

 MEDLINE, Embase, and Central databases were searched for RCTs testing genotype-GT, PFT-GT, or HTPR-Therapy in PCI-treated patients, through October 1, 2022. Two reviewers extracted the data. Risk ratios (RRs) (95% confidence intervals) were calculated. Primary outcomes were major bleedings (MBs) and major adverse cardiovascular events (MACE).

RESULTS

 In seven genotype-GT RCTs, RRs were: MB, 1.06 (0.73-1.54; p = 0.76); MACE, 0.65 (0.47-0.91; p = 0.01), but significant risk reduction was observed in RCTs performed in China (0.30, 0.16-0.54; p < 0.0001) and not elsewhere (0.75, 0.48-1.18; p = 0.21). In six PFT-GT RCTs, RRs were: MB, 0.91 (0.64-1.28, p = 0.58); MACE, 0.82 (0.56-1.19; p = 0.30): 0.62 (0.42-0.93; p = 0.02) in China, 1.08 (0.82-1.41; p = 0.53) elsewhere. In eight HTPR-Therapy RCTs, RRs were: MB, 0.71 (0.41-1.23; p = 0.22); MACE, 0.57 (0.44-0.75; p < 0.0001): 0.56 (0.43-0.74, p < 0.0001) in China, 0.58 (0.27-1.23, p = 0.16) elsewhere.

CONCLUSION

 No GT strategy affected MB. Overall, genotype-GT but not PFT-GT reduced MACE. However, genotype-GT and PFT-GT reduced MACE in China, but not elsewhere. PFT-GT performed poorly compared to HTPR-Therapy, likely due to inaccurate identification of HTPR patients by PFT.

Safety of dual antiplatelet therapy using aspirin and low-dose Prasugrel with platelet reactivity testing in flow diverter treatment of intracranial aneurysms

BACKGROUND

Dual antiplatelet therapy (DAPT) is standard care for intracranial stenting to prevent thrombotic complications. Clopidogrel resistance has resulted in patients receiving newer P2Y12 inhibitors like Prasugrel, which may reduce thrombotic complications but could increase haemorrhagic complications. This study, utilising platelet reactivity testing, compared thrombotic and haemorrhagic complications associated with Clopidogrel or 20 mg Prasugrel loading in patients treated with flow diverters (FD) for intracranial aneurysms.

METHODS

We retrospectively analysed prospectively collected data from 225 consecutive FD procedures. All patients received aspirin. 147 cases received Clopidogrel and 82 received Prasugrel. All patients had VerifyNow testing before the procedure.

RESULTS

P2Y12 non-responders were significantly more likely to have thrombotic complications than responders and hyper-responders (7% vs. 2%, p = 0.01). Low-dose Prasugrel resulted in a significantly lower rate of non-responders when compared with Clopidogrel (7% vs. 25%, p < 0.01). We found no statistically significant difference in rates of haemorrhage between the Clopidogrel and Prasugrel groups (2.4% vs. 3.9%, p = 0.47). There were 12 complications (≤7 days) in the Clopidogrel group versus 6 in the Prasugrel group (9% vs. 7.8%, respectively, p = 0.91) and a non-significant reduction in thrombotic complications in the Prasugrel group (5.2% vs. 3.9%, p = 0.88). No significant difference was shown in long-term complications between the groups (p = 0.33).

CONCLUSION

These results support the use of platelet reactivity testing and the safety of low-dose Prasugrel for FD treatment of intracranial aneurysms.