Predictors of Adherence to Anti-Impulse Therapy among Patients Treated for Acute Type-B Aortic Dissections

Medical management remains the mainstay of treatment for patients who present with acute Type-B aortic dissections (TBAD). However, it is unclear whether patients maintain adherence to their anti-impulse therapy medication regimen following hospital discharge. This study was designed to evaluate rates and predictors of medication adherence among insured patients treated for acute TBAD.

We used the Truven MarketScan database to identify US patients who presented with an acute TBAD between 2008 to 2017. Patients with continuous health insurance (Commercial or Medicare Part C) for at least 12 months after TBAD diagnosis were stratified by whether they underwent open surgical repair (OPEN), thoracic endovascular aortic repair (TEVAR), or only medication management (MED). Prescriptions for anti-impulse therapy medications were captured and adherence was defined by the medication possession ratio as > 80% fill rate over the follow-up period. Mixed-effects logistic regression models were used to identify predictors for medication adherence.

A total of 6,702 patients were identified that underwent treatment for TBAD (3% TEVAR, 9% OPEN, & 74% MED), whereas 14% received no intervention. The overall mean (±SD) rate of adherence to anti-impulse therapy was 72.6% ( ± 26), and varied based on type of TBAD intervention (73.4% TEVAR, 74.4% OPEN, & 72.4% MED). The majority of patients across all treatment groups were prescribed ≥ 2 agents, with beta-blockers and diuretics being the most common medication classes. The odds of adherence to anti-impulse therapy were significantly lower for patients who were female (OR: 0.93; 95%CI:0.85-0.99; P = 0.03), aged < 45 years (OR: 0.81; 95%CI:0.69-0.96; P < 0.001), nonadherent on preexisting therapy (OR: 0.81; 95%CI: 0.73-0.89; P < 0.001), and when medications were obtained in less than a 90 days supply from retail pharmacies.

Nearly a quarter of patients were nonadherent with anti-impulse therapy prescribed following an acute TBAD, which was more likely among younger female patients not adherent before their event. Adherence was improved among patients who received their medications by mail and when a > 90 days supply was prescribed. These findings may be used by quality improvement initiatives to improve medication adherence following TBAD and help prevent further complications.