Adverse events in patients with high platelet reactivity following successful chronic total occlusion PCI: The Assessment of Dual AntiPlatelet Therapy with Drug-Eluting Stents (ADAPT-DES) study

Rationale and design of switch Swedeheart: A registry-based, stepped-wedge, cluster-randomized, open-label multicenter trial to compare prasugrel and ticagrelor for treatment of patients with acute coronary syndrome

BACKGROUND

European treatment guidelines recommend prasugrel over ticagrelor for treating patients with non-ST-elevation acute coronary syndrome (ACS), prompting several Swedish administrative regions to transition from ticagrelor to prasugrel as the preferred treatment for patients with ACS. We aim to systematically evaluate this transition to determine the relative efficacy of prasugrel versus ticagrelor in a real-world cohort of patients with ACS.

STUDY DESIGN AND OBJECTIVES

The SWITCH SWEDEHEART trial is a prospective, multicenter, open-label, cross-sectional, stepped-wedge cluster-randomized clinical trial, in which administrative regions in Sweden will constitute the clusters. At the start of the study, all clusters will use ticagrelor as the P2Y12 inhibitor drug of choice for ACS. The order in which the clusters will implement the transition from ticagrelor to prasugrel will be randomly assigned. Every 9 months, 1 cluster will switch from ticagrelor to prasugrel as the P2Y12 inhibitor of choice for patients with ACS. The primary endpoint is the composite 1-year rate of the death, stroke, or myocardial infarction.

CONCLUSIONS

The SWITCH SWEDEHEART study will provide an extensive randomized comparison between ticagrelor and prasugrel. Novel therapies are frequently costly and supported by evidence from few or small studies, and systematic evaluation after the introduction is rare. This study will establish an important standard for introducing and evaluating the effects of health care changes within our societies.

Platelet reactivity and clinical outcomes following percutaneous coronary intervention in complex higher-risk patients

AIMS

To investigate the levels of platelet reactivity and the impact of high platelet reactivity (HPR) on long-term clinical outcomes of complex higher-risk and indicated patients (CHIP) with stable coronary artery disease (CAD) treated with elective percutaneous coronary intervention (PCI).

METHODS

We enrolled 500 patients undergoing elective PCI for stable CAD and treated with aspirin and clopidogrel. Patients were divided into four groups based on the presence of CHIP features and HPR. Primary endpoint was the occurrence of major adverse clinical events (MACE) at 5 years.

RESULTS

The prevalence of HPR was significantly greater in the CHIP population rather than non-CHIP patients (39.9% vs 29.8%, P = 0.021). Patients with both CHIP features and HPR showed the highest estimates of MACE (22.1%, log-rank P = 0.047). At Cox proportional hazard analysis, the combination of CHIP features and HPR was an independent predictor of MACE (hazard ratio 2.57, 95% confidence interval 1.30-5.05, P = 0.006).

CONCLUSION

Among patients with stable CAD undergoing elective PCI and treated with aspirin and clopidogrel, the combination of CHIP features and HPR identifies a cohort of patients with the highest risk of MACE at 5 years, who might benefit from more potent antiplatelet strategies.

Clinical Implications of "Tailored" Antiplatelet Therapy in Patients With Chronic Total Occlusion

Background

Clopidogrel nonresponsiveness is a prognostic marker after percutaneous coronary intervention. Prasugrel and ticagrelor provide a better platelet inhibition and represent the first‐line antiplatelet treatment in acute coronary syndrome. We sought to assess the prognostic impact of high platelet reactivity (HPR) and the potential clinical benefit of a “tailored” escalated or changed antiplatelet therapy in patients with chronic total occlusion.

Methods and Results

From Florence CTO‐PCI (chronic total occlusion‐percutaneous coronary intervention) registry, platelet function assessed by light transmission aggregometry, was available for 1101 patients. HPR was defined by adenosine diphosphate test ≥70% and optimal platelet reactivity by adenosine diphosphate test <70%. The endpoint of the study was long‐term cardiac survival. Patients were stratified according to light transmission aggregometry results: optimal platelet reactivity (82%) and HPR (18%). Means for the adenosine diphosphate test were 44±16% versus 77±6%, respectively. Three‐year survival was significantly higher in the optimal platelet reactivity group compared with HPR patients (95.3±0.8% versus 86.2±2.8%; P<0.001). With the availability of new P2Y₁₂ inhibitors, a deeper platelet inhibition (46±17%) and similar survival to the optimal platelet reactivity group were achieved in patients with HPR on clopidogrel therapy after escalation. Conversely, HPR on clopidogrel therapy “not switched” was associated with cardiac mortality (hazard ratio 2.37; P=0.003) after multivariable adjustment.

Conclusions

HPR on treatment could be a modifiable prognostic marker by new antiaggregants providing a deeper platelet inhibition associated with clinical outcome improvement in complex chronic total occlusion patients. A “tailored” antiplatelet therapy, also driven by the entity of platelet inhibition, could be useful in these high risk setting patients.