STS INTERMACS Database: The Key to Conduct Single-Arm Trials in Advanced Heart Failure Patients

Background: Safe introduction of novel mechanical circulatory support (MCS) devices into clinical practice is a challenging process. Single-arm trials using a control arm from existing database is an effective alternative that could be applied for regulatory approval. This study analyzes the capability of the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) database to establish objective performance criteria and select patient population that could be used for future single-arm MCS trials. Methods: Patients with INTERMACS profiles IM1-2 and IM3-5, who underwent implantation of isolated left ventricular assist devices between 2014 and 2017, were included. Both cohorts were further stratified into shock and nonshock groups using surrogate markers of shock (extracorporeal membrane oxygenation, temporary ventricular assist device, vasopressor infusions). Survival, transplantation rates, adverse events, 6-minute walk test, and quality-of-life measures were obtained for all 4 groups at 6 and 12 months. Results: Total of 7907 patients were divided into IM1-2 (n = 3909), IM3-5 (n = 3998), shock (n = 3469), and nonshock (n = 3040) groups. Recategorization occurred in 11% of patients from the IM3-5 group into the shock group. Overall, patients in the shock group had similar outcomes to the IM1-2 group (1-year survival: 86% vs 85%; P =.74). Patients in the nonshock group also had similar outcomes to the IM3-5 (1-year survival: 90% vs 90%; P =.43). Conclusions: The INTERMACS database can successfully establish objective performance criteria and concurrent control group for single-arm trials that could be used to support regulatory approval of new, less invasive MCS. INTERMACS data allow reliable comparisons of outcomes and adverse events.