To help assess the relationship between N-terminal pro-B-type natriuretic peptide (NT-proBNP) and feline cardiogenic arterial thromboembolism (ATE), the objective of this retrospective study was to compare plasma NT-proBNP concentrations between cats with cardiomyopathy that developed ATE (ATE group) and cats with occult cardiomyopathy that did not develop ATE within 1 year of testing (occult cardiomyopathy [OCM] group). The gene discussed is NPPB; the disease is cardiomyopathy.