Hideharu Tomita1, Takuya Araki2, Toshiaki Kadokami3, Satoshi Yamada4, Ryo Nakamura3, Yoshihiro Imamura5, Takaya Fukuyama3, Daisuke Nagano2, Tomoya Hashimoto6, Akiko Uematsu6, Kazuya Hosokawa3, Koujirou Yamamoto2, Shin-Ichiro Ueda7, Shin-Ichi Ando8. 1. Division of Cardiology, Shimada Hospital Ogori , Japan. Electronic address: hidetomi@zc5.so-net.ne.jp. 2. Department of Clinical Pharmacology, Gunma University Maebashi, Japan. 3. Division of Cardiology, Saiseikai Futsukaichi Hospital Chikushino, Japan. 4. Department of Hospital Pharmacy, Faculty of Medicine, University of the Ryukyus Okinawa, Japan. 5. Division of Cardiology, Aso Izuka Hospital Izuka, Japan. 6. Division of Cardiology, Shimada Hospital Ogori , Japan. 7. Department of Clinical Pharmacology & Therapeutics, University of the Ryukyus Okinawa, Japan. 8. Sleep Apnea Center, Kyushu University Hospital Fukuoka, Japan.
Abstract
INTRODUCTION: Dabigatran etexilate, a direct oral anti-coagulation agent, is used in the prevention of thromboembolism in patients with non-valvular atrial fibrillation (NVAF). However, for reasons that are not fully understood, plasma dabigatran etexilate concentrations (PDC) vary significantly among patients. METHODS: We measured trough and 90min PDC in 98 patients with NVAF. To elucidate the cause of variations in PDC, we determined correlations between PDC and various factors including renal function, co-administration of a P-glycoprotein inhibitor, and the effects of three single nucleotide polymorphisms (SNPs) of the P-glycoprotein intestinal efflux transporter. To further determine the cause of PDC variations, we examined the relationship between PDC, activated partial prothrombin time (APTT), and D-dimer (DD) levels, which are surrogate markers for thrombotic risk. RESULTS: Multivariate analysis showed significant relations among creatinine, creatinine clearance, and CHA2D2-VaSc scores (p=0.04, p=0.01, and p=0.04, respectively). In addition, creatinine and creatinine clearance were significantly correlated with trough and 90min PDC (p<0.01), respectively. There was a clear linear relation between PDC and APTT, but not DD levels. However, higher DD levels (>0.5μg/mL) were associated with lower trough and 90min PDCs. CONCLUSIONS: Renal function and CHA2D2-VaSc scores affect PDC, suggesting these may be primary factors influencing the wide variation observed in PDCs under these conditions. Variations in APTT can primarily be explained by variations in PDC; patients with lower PDCs may have a higher risk of thromboembolism events.
INTRODUCTION:Dabigatran etexilate, a direct oral anti-coagulation agent, is used in the prevention of thromboembolism in patients with non-valvular atrial fibrillation (NVAF). However, for reasons that are not fully understood, plasma dabigatran etexilate concentrations (PDC) vary significantly among patients. METHODS: We measured trough and 90min PDC in 98 patients with NVAF. To elucidate the cause of variations in PDC, we determined correlations between PDC and various factors including renal function, co-administration of a P-glycoprotein inhibitor, and the effects of three single nucleotide polymorphisms (SNPs) of the P-glycoprotein intestinal efflux transporter. To further determine the cause of PDC variations, we examined the relationship between PDC, activated partial prothrombin time (APTT), and D-dimer (DD) levels, which are surrogate markers for thrombotic risk. RESULTS: Multivariate analysis showed significant relations among creatinine, creatinine clearance, and CHA2D2-VaSc scores (p=0.04, p=0.01, and p=0.04, respectively). In addition, creatinine and creatinine clearance were significantly correlated with trough and 90min PDC (p<0.01), respectively. There was a clear linear relation between PDC and APTT, but not DD levels. However, higher DD levels (>0.5μg/mL) were associated with lower trough and 90min PDCs. CONCLUSIONS: Renal function and CHA2D2-VaSc scores affect PDC, suggesting these may be primary factors influencing the wide variation observed in PDCs under these conditions. Variations in APTT can primarily be explained by variations in PDC; patients with lower PDCs may have a higher risk of thromboembolism events.