Analysis of Factors Affecting Nontherapeutic INRs in Korean Outpatients with Mechanical Heart Valves

인공심장판막 치환환자의 치료범위를 벗어난 INR 원인분석

  • Lee Ju Yeun (Department of Pharmacy, Seoul National University Hospital) ;
  • Jeong Young Mi (Department of Pharmacy, Seoul National University Bundang Hospital) ;
  • Lee Myung Koo (College of Pharmacy, Chungbuk National University) ;
  • Kim Ki-bong (Department of Thoracic and Cardiovascular Surgery, Seoul National University Hospital) ;
  • Ahn Hyuk (Department of Thoracic and Cardiovascular Surgery, Seoul National University Hospital) ;
  • Lee Byung Koo (Department of Pharmacy, Seoul National University Bundang Hospital)
  • 이주연 (서울대학교병원 약제부) ;
  • 정영미 (분당서울대학교병원 약제부) ;
  • 이명구 (충북대학교 약학대학) ;
  • 김기봉 (서울대학교병원 흉부외과) ;
  • 안혁 (서울대학교병원 흉부외과) ;
  • 이병구 (분당서울대학교병원 약제부)
  • Published : 2005.11.01


Background: Following the implantation of heart valve prostheses, it is important to maintain therapeutic INR to reduce the risk of thromboembolism. The objectives of this study were to determine the causes of nontherapeutic INRs, and to identify the factors associated with nonadherences to warfarin therapy in Korean outpatients with prosthetic heart valves managed by a pharmacist-run anticoagulation service (ACS). Material and Method: A retrospective chart review was completed for all patients enrolled in the ACS at Seoul National University Hospital from March, 1997b to September, 2000. The data on 868 patients (5,304 visits) who were at least 6 months post-valve replacement were included. All possible causes of nontherapeutic INRs were documented for each patient visit. The association of covariates to noncompliance was investigated by univariate analysis. Result: The reasons for nontherapeutic INRs were identified as follows: inadequate dosage adjustment $(21\%)$, nonadherences to dosing regimen $(13\%)$, drug/herbal interactions $(12\%)$, changes in diet $(7\%)$, and indeterminate cause $(42\%)$. Younger age, shorter duration of ACS and longer duration of warfarin therapy were associated with nonadherence. Conclusion: In this study, nonadherence and interactions between diet and medications were found to be important factors influencing nontherapeutic INRs. Longer duration of enrollment in the ACS affected the adherence to warfarin therapy Positively whereas younger age and longer duration of warfarin therapy affected negatively.

배경: 인공심장판막 시술 후에 환자들은 혈전색전증의 위험성을 감소시키기 위해서 평생 warfarin투여를 받게 된다 한국인 환자에서 목표 INR 2.0-3.0을 유지하는 것은 여러 가지 이유로 어려움이 따른다. 이 연구의 목적은 약사에 의해서 운영되는 anticoagulation service (ACS)을 받는 한국 인공심장판막 외래환자에서 치료 범위를 벗어난 INR의 원인을 분석하고 warfarin치료에의 복약불이행과 관련된 요인들을 확인하고자 하였다. 대상 및 방법: 1997년 3월에서 2000년 9월까지 서울대학교병원에서 ACS를 방문한 모든 환자의 의무기록을 후향적으로 검토하였다. 수술 후 6개월이 경과된 화자로 INR 2.0 미만과 INR 3.0초과가 한 번 이상 있는 환자 866명(5,304회 방문)을 대상으로 치료 범위를 벗어난 INR의 가능한 모든 원인들을 환자 방문 때마다 분석하였다 성별, 연령, ACS 상담을 받은 기간 및 warfarin 치료 기간과 복약불이행과의 상관성은 단변수 분석으로 확인하였다. 걸과· 비치료범위의 INR의 원인은 다음과 같았다: 부적절한 용량 조절$(21\%)$, 복약불이행$(13\%)$, 약물-약물/한약 상호작용$(12\%)$, 식이의 변화$(7\%)$, 확인불가$(42\%)$. 낮은 연령, 짧은 ACS 상담 기간, 장기간의 warfarin 치료가 복약불이행과 관련이 있었다 결론: 이 연구에서 복약불이행, 약물과 식이의 상호작용이 비치료범위의 INR의 중요한 요인임이 확인되었다. 낮은 연령과 장기간의 warfarin치료 기간이 복약불이행과 상관이 있었던 반면 ACS 등록된 기간이 길수록 warf arin에 대한 치료 순응도가 높아졌다.



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