Khan MS, et al. - In this exploratory post-hoc analysis of the Treatment of Preserved Cardiac Function Heart Failure With an Aldosterone Antagonist Trial, researchers evaluated the country-level variations in placebo effect, given significant interest in evaluating regional difference in patient features and treatment impacts has been incited by globalization of clinical trials. They assessed alterations in the overall summary score (OSS) and clinical summary score (CSS) of the Kansas City Cardiomyopathy Questionnaire at 4, 12, 24, 36, 48, and 60 months, as the main outcomes. The placebo arm comprised of 1,723 people. Although the lowest OSS and CSS at baseline was noted in patients from Georgia, these patients demonstrated at all time points the highest improvement (> 10 points) in CSS than other countries (United States, Canada, Russia, Brazil, Argentina). Relative to patients from United States and Canada, patients enrolled in Georgia exhibited more than 3 times the improvement in OSS. At all time points, a significantly higher improvement in OSS and CSS was observed in patients enrolled in Argentina vs other countries, except Georgia. Findings revealed that in patients receiving placebo, longitudinal alterations in Kansas City Cardiomyopathy Questionnaire scores differed significantly across countries.