Relationship Between Enrolling Country Income Level and Patient Profile, Protocol Completion, and Trial End Points: From the ASCEND-HF Trial

Background: Globalization of clinical trials fosters inclusion of higher and lower income countries, but the influence of enrolling country income level on heart failure trial performance is unclear. This study sought to evaluate associations between enrolling country income level, acute heart failure patient profile, protocol completion, and trial end points. Methods and Results: The ASCEND-HF (Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure) trial included 7141 patients with acute heart failure from 30 countries. Country income data in gross national income per capita in current US dollars from the year 2007 (ie, the year trial enrollment began) were abstracted from the World Bank. Patients were grouped by enrolling country income level (ie, high [>$11 455], upper middle [$3706-$11 455], lower middle [$936-$3705], and low [ Conclusions: In this global acute heart failure trial, patients from higher income countries had lower rates of protocol completion, higher rates of adverse events, and similar mortality rates. After adjustment for race, geographic region, and clinical factors, enrollment from a higher income country was associated with worse clinical outcomes, driven by higher rates of rehospitalization. Variation in enrolling country income level may influence study end points and trial performance independent of geographic region