Effect of allogeneic adipose tissue‐derived mesenchymal stromal cell treatment in chronic ischaemic heart failure with reduced ejection fraction – the SCIENCE trial.

Aims: The aim of the SCIENCE trial was to investigate whether a single treatment with direct intramyocardial injections of adipose tissue‐derived mesenchymal stromal cells (CSCC_ASCs) was safe and improved cardiac function in patients with chronic ischaemic heart failure with reduced ejection fraction (HFrEF). Methods and results: The study was a European multicentre, double‐blind, placebo‐controlled phase II trial using allogeneic CSCC_ASCs from healthy donors or placebo (2:1 randomization). Main inclusion criteria were New York Heart Association (NYHA) class II–III, left ventricular ejection fraction (LVEF) <45%, and N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) levels >300 pg/ml. CSCC_ASCs or placebo (isotonic saline) were injected directly into viable myocardium. The primary endpoint was change in left ventricular end‐systolic volume (LVESV) at 6‐month follow‐up measured by echocardiography. A total of 133 symptomatic HFrEF patients were included. The treatment was safe without any drug‐related severe adverse events or difference in cardiac‐related adverse events during a 3‐year follow‐up period. There were no significant differences between groups during follow‐up in LVESV (0.3 ± 5.0 ml, p = 0.945), nor in secondary endpoints of left ventricular end‐diastolic volume (−2.0 ± 6.0 ml, p = 0.736) and LVEF (−1.6 ± 1.0%, p = 0.119). The NYHA class improved slightly within the first year in both groups without any difference between groups. There were no changes in 6‐min walk test, NT‐proBNP, C‐reactive protein or quality of life the first year in any groups. Conclusion: The SCIENCE trial demonstrated safety of intramyocardial allogeneic CSCC_ASC therapy in patients with chronic HFrEF. However, it was not possible to improve the pre‐defined endpoints and induce restoration of cardiac function or clinical symptoms. [ABSTRACT FROM AUTHOR]