A new biomarker of cardiac resynchronization therapy response: cGMP to mature BNP ratio

•Previous studies have failed to reveal the predictive power of brain/B-type natriuretic peptide (BNP) for cardiac resynchronization therapy (CRT) response.•BNP comprises mature BNP with full bioactivity and proBNP with 15% activity.•We can calculate total BNP, proBNP, and estimated mature BNP (emBNP) by using two BNP kits.•Each BNP form along with cyclic guanosine monophosphate (cGMP) was assessed to predict CRT response.•The cGMP to emBNP ratio was found to be a promising predictor of CRT responders.