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Published on: January 18, 2018
Long-Term Vascular Function in CTO Recanalization: A Randomized Clinical Trial of Ticagrelor vs. Clopidogrel
Juan J Rodriguez-Arias1, Josep Gomez-Lara2, Juan Caballero-Borrego3
1Cardiovascular Institute, Hospital Clinic, Institut d'Investigacions Biomèdiques August Pi i Sunyer, (IDIBAPS), University of Barcelona, Barcelona, Spain.
Insights
Dual antiplatelet therapy with ticagrelor maintained coronary blood flow in chronic total occlusions post-procedure. Clopidogrel showed improved flow over time, suggesting ticagrelor
Area of Science:
- Cardiology
- Interventional Cardiology
- Pharmacology
Background:
- Coronary vascular function is impaired after recanalizing chronic total occlusions (CTOs).
- Ticagrelor loading doses partially improve this function compared to clopidogrel.
- Long-term vascular function and the impact of 1-year dual antiplatelet therapy (DAPT) remain unclear.
Purpose of the Study:
- To assess long-term coronary vascular function after CTO recanalization.
- To compare the effects of ticagrelor versus clopidogrel on coronary blood flow (CBF) during 1-year DAPT.
Main Methods:
- Prospective, open-label, randomized controlled trial (TIGER study) of 50 CTO patients.
- 1:1 randomization to ticagrelor or clopidogrel loading dose and 1-year DAPT.
- Coronary blood flow (CBF) assessed via adenosine infusion post-dose and at follow-up.
Main Results:
- CBF was higher in the ticagrelor group post-dose and maintained at follow-up (p=0.071).
- Ticagrelor-related CBF remained sustained (p=0.933), while clopidogrel-related CBF significantly increased over time (p=0.039).
- 38 patients completed angiographic follow-up; 35 had Doppler data.
Conclusions:
- Ticagrelor-based DAPT maintained non-significantly higher CBF in recanalized CTOs versus clopidogrel.
- Clopidogrel-treated patients showed initial lower CBF with significant improvement at follow-up.
- Further evaluation in larger cohorts is warranted to confirm the clinical significance of sustained high coronary flow.
Background:
Coronary vascular function of a chronic coronary total occlusion (CTO) immediately after recanalization is known to be poor and to be partially improved by pre-treatment with loading dose of ticagrelor vs. clopidogrel. It is unknown if this vascular dysfunction is maintained at long-term follow-up and may be improved by 1-year dual antiplatelet therapy (DAPT).
Methods:
The TIGER is a prospective, open-label, two parallel-group controlled clinical trial, which 1:1 randomized 50 CTO patients to pre-PCI loading dose and subsequent 1-year DAPT with ticagrelor vs. clopidogrel. Coronary blood flow (CBF) under stepwise adenosine infusion was assessed after drug loading dose and at follow-up and compared between the two drug groups, adjusting for time of follow-up.
Results:
Out of 50 patients with index CBF evaluation, 38 (76%) patients underwent angiographic follow-up (23 and 15 at 1 and 3-year, respectively) and Doppler data was available in 35 (70%). A high CBF area under the curve (AUC), already observed after loading dose in ticagrelor vs. clopidogrel group (p = 0.027), was maintained at follow-up (AUC 34815.22 ± 24,206.06 vs. AUC 22712.47 ± 13,768.95; p = 0.071). Specifically, whereas high ticagrelor loading dose-related CBF was sustained at follow-up (p = 0.933), clopidogrel loading dose-related CBF increased at follow-up (p = 0.039).
Conclusion:
The TIGER trial showed that DAPT with ticagrelor maintained a non-significantly higher CBF in a recanalized CTO as compared to clopidogrel, whose treated patients exhibit a lower CBF immediately after PCI with a significant increase at follow-up. The clinical value of such sustained high coronary flow should be evaluated in a larger group of patients.
Clinical Trial Registration:
https://clinicaltrials.gov/ct2/show/NCT02211066 (ClinicalTrials.gov number NCT02211066).
