An investigation of INR home monitoring in patients with adult congenital heart disease (ACHD)

Student thesis: Doctoral Thesis


Congenital heart disease (CHD) is an umbrella term for a range of conditions that affect the structure of the heart, and is present from birth. Adults with CHD may require lifelong cardiac follow-up. Patients with CHD have an increased risk of stroke compared to age-matched, control populations and therefore may require lifelong warfarin therapy. Warfarin has a narrow therapeutic index and requires monitoring of the international normalised ratio (INR). An INR can be tested at a hospital or GP warfarin clinic, or can be done at home by the patient.

(i) Systematic Review
A computerised search of the following databases from inception to May 2022 was performed: Medline, Embase, Cochrane, CINAHL and Scopus.
(ii) Pilot observational study
A pilot observational study examined warfarin monitoring in patients with congenital heart disease. Two cohorts were followed for 12 months – one using standard clinic monitoring and the other using INR home monitoring (INR-HM). A health-related quality of life (HRQoL) survey and a patient satisfaction questionnaire were completed at the end of the follow-up period.
(iii) Study of medical professionals’ views on INR home monitoring Medical professionals’ views on INR-HM was examined using interviews and an online survey.

Systematic Review
The use of home monitoring programmes may be beneficial in reducing mortality, enabling earlier and more timely detection and treatment of CHD complication.

Pilot observational study
Time in therapeutic range (TTR) and HRQoL trended higher with INR-HM and INR variability trended lower, indicating that INR-HM may be safer for ACHD patients. HRQoL trended higher with INR-HM and patient satisfaction with INR-HM was high.

Study of medical professionals’ views on INR home monitoring
The majority of GPs surveyed (69%) had a positive opinion of INR-HM, however despite this, INR-HM is not widely facilitated by general practice throughout the UK.
Date of AwardSept 2023
Original languageEnglish
SupervisorCiara Hughes (Supervisor), Sonyia Mc Fadden (Supervisor) & Jacqui Crawford (Supervisor)


  • Warfarin
  • Point of care testing

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