The Role of Phosphodiesterase-5 Enzyme Inhibitors and Prostacyclin Analogs in Reactive Pulmonary Vasculopathy in Systolic Heart Failure: A Narrative Review

Reactive pulmonary vasculopathy, the precapillary component of pulmonary hypertension due to left heart disease, is characterized by mean pulmonary arterial pressure >25 mmHg, pulmonary capillary wedge pressure >15 mmHg, transpulmonary gradient ≥12 mmHg, and pulmonary vascular resistance ≥3 Wood units. This condition complicates systolic heart failure and is associated with adverse outcomes. This narrative review evaluates the role of phosphodiesterase-5 (PDE-5) inhibitors and prostacyclin analogs in its management. A comprehensive literature search of PubMed, Cochrane Library, and Embase from January 2000 to September 2024, supplemented by reference screening, identified randomized controlled trials, observational studies, and case series investigating these therapies in systolic heart failure with pulmonary hypertension. Evidence synthesis considered both hemodynamic outcomes, such as pulmonary pressures, vascular resistance, and right ventricular function, as well as clinical endpoints, including exercise capacity, quality of life, and survival. PDE-5 inhibitors, particularly sildenafil, demonstrated improvements in pulmonary hemodynamics, endothelial function, and exercise tolerance, while prostacyclin analogs such as epoprostenol, iloprost, and treprostinil provided potent vasodilatory and antiproliferative effects with benefits in advanced disease and right ventricular protection. Combination therapy has shown potential synergistic effects, although data remain limited. Safety profiles, including risks of systemic hypotension and drug-specific side effects, are discussed separately from efficacy findings. Current evidence is limited by small study sizes, heterogeneity of design, and a lack of robust data specifically targeting Group 2 pulmonary hypertension. Overall, PDE-5 inhibitors and prostacyclin analogs appear promising in addressing reactive pulmonary vasculopathy in systolic heart failure, but larger, well-designed trials are required to establish their clinical utility.