Aims: Pulmonary hypertension (PH) due to systolic left ventricular dysfunction (PH-sLVD) frequently complicates heart failure (HF), and greatly worsens the prognosis of patients with sLVD, but as yet has no approved treatment. The LEPHT study aims to characterize the haemodynamic profile, safety, tolerability, and pharmacokinetic profile of riociguat (BAY 63-2521), an oral stimulator of soluble guanylate cyclase, in patients with PH-sLVD.
Methods and results: This 16-week, phase IIb, randomized, placebo-controlled, double-blind study enrols patients with PH-sLVD, defined as left ventricular ejection fraction (LVEF) ≤40% and mean pulmonary arterial pressure (PAP(mean)) ≥25 mmHg at rest. Patients using optimized HF medication will receive placebo or riociguat 0.5 mg, 1 mg, or up to 2 mg three times daily. The dose will be titrated for 8 weeks, based on systolic blood pressure and well-being, followed by 8 weeks of treatment at a stable dose. The primary efficacy variable is PAP(mean), while secondary efficacy endpoints include LVEF, exercise capacity, quality of life, and other haemodynamic and echocardiographic measurements. Safety and pharmacokinetics will also be assessed. After the 16-week study, patients will have the opportunity to be treated with riociguat in a long-term extension phase.
Conclusion: The LEPHT study will provide valuable information on the haemodynamic, echocardiographic, and preliminary clinical effects of riociguat in patients with PH-sLVD. Trial registration NCT01065454.