ABSTRACT
Fractional flow reserve is a simple and efficient tool to assess the severity of an intermediate lesion in order to determine the optimal therapy. However there are some limitations to its use. We observed that in patients with an occluded artery, FFR measurements in the vessel supplying collaterals can be underestimated leading to inappropriate therapy.
Subject(s)
Angioplasty, Balloon, Coronary , Coronary Angiography/methods , Coronary Circulation , Coronary Occlusion , Severity of Illness Index , Adult , Collateral Circulation , Coronary Occlusion/diagnostic imaging , Coronary Occlusion/physiopathology , Coronary Occlusion/therapy , Humans , MaleSubject(s)
Coronary Vessels/surgery , Hemorrhage/etiology , Platelet Activation/drug effects , Platelet Aggregation Inhibitors/therapeutic use , Ticlopidine/analogs & derivatives , Aged , Cardiovascular Surgical Procedures/adverse effects , Clopidogrel , Female , Humans , Male , Middle Aged , Ticlopidine/therapeutic useABSTRACT
INTRODUCTION: High on-treatment platelet reactivity (HTPR) after clopidogrel loading dose (LD) is associated with a high risk of thrombotic events after percutaneous coronary intervention(PCI). We have demonstrated that HTPR could be overcome in the majority of cases using LD adjustment resulting in an improved clinical outcome. However this strategy failed in nearly 10% of patients with HTPR. We aimed to determine if P2Y12-ADP receptor polymorphisms were associated with failed dose adjustment. MATERIAL AND METHOD: Forty-three patients undergoing PCI were included in this prospective study. A VASP index >or=50% after a 600 mg LD of clopidogrel defined HTPR. Dose adjustment was performed according to PR monitoring to reach a VASP index <50%. Genetic polymorphism of the P2Y12-ADP receptor was determined by direct sequencing. RESULTS: Patients with successful dose-adjustment (SDA) (n=33) and failed (FDA) (n=10) dose-adjustment groups were compared. The 2 groups were similar in terms of cardiovascular risk factors including diabetes mellitus (SDA vs FDA: 42 vs 20%; p=0.3). The prevalence of the H2 allele of the P2Y12-ADP receptor was also similar between the 2 groups (p=0.3). The H2 allele was found in 6 patients which are all included in the SDA group. After the first 600 mg loading dose of clopidogrel, patients carrying at least one H2 allele had similar VASP index compared to those carrying two copies of the wild type allele (H1) (SDA vs FDA: 44.9+/-14.9 vs 43.5+/-10%; p=0.8). CONCLUSION: The present study suggests that the H2 allele of the P2Y12-ADP receptor is not involved in clopidogrel failed dose adjustment according to platelet reactivity monitoring.
