In Reply Dr Guazzi and colleagues suggest that the presence of comorbidities such as
obesity, atrial dysrhythmias, and anemia might have made patients with HFPEF less apt to derive
benefit from phosphodiesterase-5 inhibition. These comorbidities are typical in patients with HFPEF
in the community.1 Heart failure with normal EF in the
absence of comorbidities is usually termed restrictive cardiomyopathy, and this is
a much less common form of HF than the type that we set out to study in the RELAX trial.
Redfield MM, Borlaug BA. Sildenafil and Exercise Capacity in Heart Failure—In
Reply. JAMA. 2013;310(4):432-433. doi:10.1001/jama.2013.7440