WHO Group 2 : Pulmonary Hypertension with Left Heart Disease
Group 2 pulmonary hypertension is the most prevalent cause of pulmonary hypertension worldwide, representing >50% of cases. Within that group Pulmonary Hypertension in Heart Failure with Preserved Ejection Fraction (PH-HFpEF) represents the most common form, with an estimated US prevalence of more than 1.5 million patients.
Clinically, these patients present with symptoms identical to Group 1 PAH patients, namely shortness of breath, leg edema, and poor exercise capacity. The distinction between these two groups requires medical testing, including a right heart catheterization. The disease involves abnormalities of the left ventricle which has reduced compliance, an elevation in the left atrial pressure (aka pulmonary capillary wedge pressure (PCWP), an elevation in pulmonary arterial pressure, and reduced function of the right ventricle. Thus, it is a complex disease involving the heart and pulmonary circulation together.