Phosphodiesterase-5 (PDE5) Inhibition and Pulmonary Hypertension in Diastolic Heart Failure

Study Overview
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Brief Summary
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Prevalence of heart failure (HF) with left ventricular (LV) diastolic dysfunction and preserved ejection fraction (EF) (HFpEF) is increasing. Prognosis worsens with development of pulmonary vasoconstriction and hypertension (PH) and right ventricular (RV) failure. The investigators aimed at modulating pulmonary vascular tone and RV burden in HFpEF due to high blood pressure (HBP), by using the phosphodiesterase-5 (PDE5) inhibitor sildenafil.

Detailed Description
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Heart failure (HF) with preserved left ventricular (LV) ejection fraction (EF) (HFpEF) is a public health problem and a major topic in clinical cardiology. Its prevalence, in fact, is increasing and the outcome seems to be similar to that of HF with LV systolic dysfunction (LVSD). Pulmonary hypertension (PH) in HFpEF is highly prevalent and often severe and, like in LVSD (3), is a predictor of morbidity and mortality (4). Because of the thin wall and the distensibility, the right ventricle (RV) is much more vulnerable by an excessive afterload than by preload. The pulmonary circulation is a central determinant of RV afterload, and an increase in impendance to RV ejection, like occurring in LV dysfunction, can easily result in RV failure, tricuspid regurgitation, central venous pressure (CVP) rise. Development of RV failure is unanimously viewed as a predictor of poor prognosis but the underlying mechanisms have not been extensively investigated. Because of the prevalence and clinical significance of PH secondary to HF, attenuation of the pulmonary vascular tone and of the RV hemodynamic burden has been suggested as a goal to be achieved with HF therapy. Attempts with endothelin receptor antagonists, or prostacyclin analogues, were basically unsuccessful. Experimental models and human studies, showing that in HF nitric oxide (NO) - dependent pulmonary vasodilatation is impaired and pulmonary vascular resistance elevation is at least in part due to pulmonary endothelial dysfunction, have suggested therapeutic strategies with agents that increase NO activity, like nitrates or phosphodiesterase - 5 (PDE5) inhibitors (12-14). The latter agents offer the double advantage of selectively dilating the pulmonary vessels and not producing tachyphylaxis. In this 1-year duration study, the primary end-point was to probe whether pulmonary hemodynamics and RV performance in HFpEF with PH may be targets of PDE5 inhibition with sildenafil.

Official Title
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Pulmonary Hypertension Secondary to Heart Failure With Preserved Systolic Function: a Target of Phosphodiesterase - 5 Inhibition in a 1- Year Duration Study

Conditions
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Pulmonary Hypertension, Diastolic Heart Failure

Intervention / Treatment
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* Drug: Sildenafil
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: LVEF >50% sinus rhythm and stable clinical condition defined as no changes in therapeutic regimen, or hospitalization in the 6 months preceding recruitment. pulmonary artery systolic pressure > 40 mm Hg, Exclusion Criteria: Patients receiving nitrates A history of pulmonary disease Alternative causes of PH other than cardiac-related Renal failure (creatinine > 2mg/dL) Anemia Pericardial disease Cardiac amyloidosis
Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Sildenafil<br> | Drug: Sildenafil<br>* 50 mg 3 times/day for 1 year<br>|
| Placebo Comparator: Placebo<br> | Drug: Placebo<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pulmonary hemodynamics |  | 1 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Diastolic Heart Failure, Pulmonary Hypertension