PDE5A and aortic stenosis: AS patients with grade 2–3 immunoreactivity (n = 13) had higher pulmonary capillary wedge pressures and serum NT-proBNP levels than AS patients with grade 1 PDE5 immunoreactivity (n = 7) (18±2 vs 11±1 mmHg, and 1090±254 vs 403±221 ng/l, respectively, P<0.05 for both).