NPPB and hypertrophic cardiomyopathy: RCT: Randomized controlled trial; HOCM: Hypertrophic Obstructive Cardiomyopathy; NHCM: Non-Hypertrophic Cardiomyopathy; LVOT: Left Ventricular Outflow Tract; NYHA: New York Heart Association; LAVI: Left Atrial Volume Index; LVMI: Left Ventricular Mass Index; NT-proBNP - N-terminal Pro B-type Natriuretic Peptide.