Medication adherence patterns in aortic dissection survivors

Background & objectives: Beta-blockers have been shown to improve survival in both type A and type B acute aortic dissection (AAD) patients. Calcium channel blockers have been shown to selectively improve survival only in type B AAD patients. There is a lack of data on medication adherence in AAD survivors. The purpose of this study was to assess medication adherence in patients who survived an AAD. Methods: This was a cross-sectional survey-based study of individuals from a single medical centre which was part of the larger International Registry of Acute Aortic Dissection (IRAD). Patients with type A or B AAD who survived to discharge were included in this study. Individuals who were deceased based on the results of an online Social Security Death Index were excluded from the study. Data were obtained from both a survey and also from abstraction from the local academic institution's IRAD registry. A survey packet was sent to patients. One section of this survey was dedicated to assessing medication adherence using the 4-item Morisky scale. Results: Eighty two completed surveys were returned; 74 patients completed the section of the survey pertaining to medication adherence (response rate 38%). Morisky score was >= 1.0 for 27 (36%) patients and 0 for 47 (64%) patients. Thirty three patients reported yes to 'forget to take medications' and eight reported yes to 'careless with medications.' Medication non-adherence (defined as a score of >= 1.0 on Morisky) was associated with increased follow up recurrence of chest pain at one year of follow up. Only two patients stopped their antihypertensive on their own and did not cite a reason for doing this. Interpretation & conclusions: The medication adherence rate for patients who survived an AAD was 64 per cent at a median (Q1, Q3) of 7.1 yr (5.6, 11.5) after discharge, as per the Morisky scale. The clinicians should educate their patients on the importance of antihypertensive therapy and assess for forgetfulness and carelessness at each clinic visit, as well as understand patients' beliefs about drug therapy, all of which have been shown to increase medication adherence.