Platelet reactivity in patients receiving a maintenance dose of P2Y12-ADP receptor antagonists undergoing elective percutaneous coronary intervention

TIcagrelor in Rotational Atherectomy to Reduce TROPonin Enhancement: The TIRATROP Study, A Randomized Controlled Trial

BACKGROUND

Because rotational atherectomy (RA) is associated with arterial trauma and platelet activation, patients treated with RA may benefit from more potent antiplatelet drugs. The aim of this trial was to assess the superiority of ticagrelor over clopidogrel in reducing post procedure troponin release.

METHODS

TIRATROP (TIcagrelor in Rotational Atherectomy to reduce TROPonin enhancement) is a multicenter double-blind randomized controlled trial that included 180 patients with severe calcified lesions requiring RA who received either clopidogrel (300 mg loading dose, then 75 mg/d) or ticagrelor (loading dose 180 mg then 90 mg twice daily). Blood samples were collected at the beginning (T0), and 6, 12, 18, 24 and 36 h after the procedure. Primary end point was troponin release within the first 24 h using area under the curve analysis (troponin level as a function of time).

RESULTS

The mean age of patients was 76 ± 10 years, 35% had diabetes. RA was used to treat 1, 2 or 3 calcified lesions in 72%, 23% and 5% of patients, respectively. Troponin release within the first 24 h was similar in both the ticagrelor (adjusted mean ±SD of ln AUC 8.85 ± 0.33) and the clopidogrel (8.77 ± 0.34, p = 0.60) arms. Independent predictors for troponin enhancement were acute coronary syndrome presentation, renal failure, elevated C-Reactive protein and multiple lesions treated with RA.

CONCLUSION

Troponin release did not differ among treatment arms. Our results suggest that greater platelet inhibition does not affect periprocedural myocardial necrosis in the setting of RA.

Comparison of Clinical Outcomes Between Ticagrelor and Clopidogrel in Acute Coronary Syndrome: A Comprehensive Meta-Analysis

Background

Ticagrelor is currently recommended for patients with the acute coronary syndrome (ACS). However, recent studies have yielded controversial results.

Objective

To compare the clinical outcomes between ticagrelor and clopidogrel in patients with ACS.

Methods

Three electronic databases were queried until April 25, 2021. We defined major adverse cardiovascular events (MACEs) as the primary efficacy endpoint. The secondary efficacy endpoints included stroke, stent thrombosis, cardiovascular death, all-cause death, and myocardial infarction. The safety endpoints were (major and minor) bleeding. Odds ratios (ORs) and 95% CIs were calculated to represent the estimated effect sizes.

Results

A total of 270,937 patients with ACS from 10 clinical trials and 18 observational studies were included. No significant difference was detected in MACE (OR 0.81, 95% CI 0.60–1.08, p = 0.15, I2 = 64.83%). However, ticagrelor introduced a higher risk of bleeding (1.46, 1.17–1.83, 0.00, 61.66%) and minor bleeding (1.71, 1.33–2.21, 0.00, 4.65%) in clinical trials. The results of secondary efficacy endpoints differed in the clinical trials and observational studies. Subgroup analysis demonstrated that ticagrelor showed better therapeutic effects in patients who underwent the percutaneous coronary intervention (PCI) (0.38, 0.23–0.63, 0.00, 0) than those intended for PCI (1.03, 0.76–1.38, 0.87, 64.26%). Meanwhile, ticagrelor showed different therapeutic effects on patients with ACS of different ethnicities and different countries.

Conclusion

This meta-analysis demonstrated that ticagrelor is not superior to clopidogrel in MACE but is associated with a higher risk of bleeding in patients with ACS. Different PCI strategies, ethnicities, and countries may be the factors that contribute to different therapeutic effects of ticagrelor.

Systematic Review Registration

This study is registered with PROSPERO (CRD42021251212).

Association between High Platelet Reactivity Following Dual Antiplatelet Therapy and Ischemic Events in Japanese Patients with Coronary Artery Disease Undergoing Stent Implantation

AIM

Although high on-treatment platelet reactivity (HTPR) with dual antiplatelet therapy (DAPT) correlates with long-term adverse outcomes in patients undergoing percutaneous coronary intervention, the correlation in Japanese patients remains unclear. Therefore, we examined the relationship between platelet reactivity during DAPT with aspirin and clopidogrel and 1-year clinical outcomes following successful coronary stent implantation.

METHODS

A prospective, multicenter registry study (j-CHIPS) was conducted in patients undergoing coronary stenting and receiving aspirin and clopidogrel at 16 hospitals in Japan. A VerifyNow point-of-care assay was used to assess platelet reactivity, and a cutoff value to define HTPR was established.

RESULTS

Between February 2011 and May 2013, 1047 patients were prospectively enrolled, of which 854 patients with platelet function evaluation at 12-24 h after PCI were included in the final analysis. After 1 year of follow-up, the incidence of the primary endpoint (a composite of all-cause mortality, myocardial infarction, stent thrombosis, and ischemic stroke) was significantly higher in patients with HTPR than in those without (5.9% vs. 1.5%, p=0.008), and HTPR showed a modest ability to discriminate between patients who did and did not experience major adverse cardiac and cerebrovascular events (area under the curve, 0.60; 95% confidence interval, 0.511-0.688, p=0.039). HTPR status did not identify patients at risk for major or minor bleeding events.

CONCLUSION

HTPR was significantly associated with adverse ischemic outcomes at 1 year after PCI in Japanese patients receiving maintenance DAPT, indicating its potential as a prognostic indicator of clinical outcomes in this high-risk patient population.

Study of Two Dose Regimens of Ticagrelor Compared With Clopidogrel in Patients Undergoing Percutaneous Coronary Intervention for Stable Coronary Artery Disease

BACKGROUND

Ticagrelor has superior efficacy to clopidogrel in the management of acute coronary syndromes but has not been assessed in patients undergoing percutaneous coronary intervention for stable coronary artery disease. We compared the pharmacodynamic effects of ticagrelor and clopidogrel in this stable population.

METHODS

One hundred eighty aspirin-treated stable coronary artery disease patients, who were planned to undergo elective percutaneous coronary intervention in a single center, were randomized 1:1:1 to either a standard clopidogrel regimen or 1 of 2 regimens of ticagrelor, either 90 mg (T90) or 60 mg twice daily (T60), both with a 180 mg loading dose. Cellular adenosine uptake was assessed, at the time of the procedure and pre- and postdose at 1 month, by adding adenosine 1 µmol/L to aliquots of anticoagulated whole blood and mixing with a stop solution at 0, 15, 30, and 60 seconds, then measuring residual plasma adenosine concentration by high-performance liquid chromatography. Systemic plasma adenosine concentration and platelet reactivity were assessed at the same timepoints. High-sensitivity troponin T was measured pre- and 18 to 24 hours postpercutaneous coronary intervention.

RESULTS

One hundred seventy-four patients underwent an invasive procedure, of whom 162 received percutaneous coronary intervention (mean age 65 years, 18% female, 21% with diabetes mellitus). No effect on in vitro adenosine uptake was seen postdose at 1 month for either ticagrelor dose compared with clopidogrel (residual adenosine at 15 seconds, mean±SD: clopidogrel 0.274±0.101 µmol/L; T90 0.278±0.134 µmol/L; T60 0.288±0.149 µmol/L; P=0.37). Similarly, no effect of ticagrelor on in vitro adenosine uptake was seen at other timepoints, nor was plasma adenosine concentration affected (all P>0.1). Both maintenance doses of ticagrelor achieved more potent and consistent platelet inhibition than clopidogrel (VerifyNow P2Y12 reaction units, 1 month, mean±SD: predose, T60: 62±47, T90: 40±38, clopidogrel 181±44; postdose, T60: 34±30, T90: 24±21, clopidogrel 159±57; all P<0.0001 for ticagrelor versus clopidogrel). High platelet reactivity was markedly less with both T60 and T90 compared with clopidogrel (VerifyNow P2Y12 reaction units>208, 1 month postdose: 0%, 0%, and 21%, respectively). Median (interquartile range) high-sensitivity troponin T increased 16.9 (6.5-46.9) ng/L for clopidogrel, 22.4 (5.5-53.8) ng/L for T60, and 17.7 (8.1-43.5) ng/L for T90 (P=0.95). There was a trend toward less dyspnea with T60 versus T90 (7.1% versus 19.0%; P=0.09).

CONCLUSIONS

Maintenance therapy with T60 or T90 had no detectable effect on cellular adenosine uptake at 1 month, nor was there any effect on systemic plasma adenosine levels. Both regimens of ticagrelor achieved greater and more consistent platelet inhibition than clopidogrel but did not appear to affect troponin release after percutaneous coronary intervention.

CLINICAL TRIAL REGISTRATION

URL: https://www.

CLINICALTRIALS

gov. Unique identifier: NCT02327624.

Dabigatran versus vitamin k antagonist: an observational across-cohort comparison in acute coronary syndrome patients with atrial fibrillation

Essentials Acute coronary syndrome (ACS) with atrial fibrillation (AF) is a therapeutic challenge. Dual and triple antithrombotic therapy showed a similar thrombotic risk in ACS patients with AF. The omission of aspirin during the first month did not increase the rate of ischemic events. Replacement of vitamin K antagonist by dabigatran leads to an increased thrombotic risk.

SUMMARY

Background Dual antithrombotic therapy comprising a vitamin K antagonist (VKA) plus clopidogrel reduces the incidence of major bleeding compared with triple therapy (VKA + clopidogrel + aspirin) in acute coronary syndrome (ACS) patients with atrial fibrillation (AF), with a similar thrombotic risk. The oral thrombin inhibitor dabigatran (150 mg twice a day) showed superiority over VKA in non-valvular AF, but data supporting its use in AF patients presenting with ACS are limited. Objective We sought to evaluate the efficacy of dabigatran vs. VKA in the management of AF patients undergoing percutaneous coronary intervention for an ACS. Methods In this open-label study, 133 consecutive patients received dabigatran plus clopidogrel. Another cohort of 133 patients treated with VKA plus clopidogrel was used as the control group. Results After propensity score adjustment, the cumulative incidence of major adverse cardiovascular events over 24 months was higher with dabigatran vs. VKA (adjusted hazard ratio, 2.28; 95% confidence interval, 1.46-3.56). Similar rates of major bleeding were found (adjusted hazard ratio, 1.17; 95% confidence interval, 0.46-2.96). Conclusions In AF patients presenting with ACS, replacement of VKA by dabigatran concurrently with clopidogrel is associated with an increased thrombotic risk, without a reduction in major bleeding.