Pulmonary Vascular Disease: Hemodynamic Assessment and Treatment Selection-Focus on Group II Pulmonary Hypertension

Pulmonary hypertension due to left heart disease (PH-LHD) is the most common cause of pulmonary hypertension worldwide, yet therapies used to treat pulmonary arterial hypertension have failed to show efficacy in this population. Proper hemodynamic assessment and differentiation of pulmonary hypertension phenotypes is therefore critical for both current clinical practice and future research and therapeutic efforts.

Substantial recent efforts have sought to improve the hemodynamic characterization of pulmonary hypertension for both diagnostic and prognostic purposes. These efforts include identifying occult LHD using provocative maneuvers as well as sub-classifying PH-LHD based on the presence or absence of a pre-capillary component. How to best define the pre-capillary component remains controversial as several studies have drawn conflicting conclusions. The lack of standardization of hemodynamic measurements as well as measurement fidelity concerns may explain some of the discrepant results. Non-hemodynamic methods of PH-LHD classification may also have an emerging role. Despite recent advances, therapeutic studies have largely remained disappointing. In this review, we discuss the nuances and controversies surrounding diagnostic and prognostic hemodynamic characterization of PH-LHD as well as summarize the recent therapeutic efforts and ongoing challenges in this population.