Sildenafil (eller placebo) blev adderet patienternes standardbehandling, som kunne omfatte en kombination af antikoagulantia, digoxin, calciumkanalblokkere, diuretika eller oxygen.
Sildenafil (or placebo) was added to patients’ background therapy which could have included a combination of anticoagulation, digoxin, calcium channel blockers, diuretics or oxygen.