WHO's in Second?

Abstract

World Health Organization (WHO) group 2 pulmonary hypertension (PH) due to left-side heart disease (ie, heart failure or left-sided valvular heart disease) is the most common form of PH in western countries. Distinguishing patients with WHO group 2 PH, particularly the subset of patients with PH due to heart failure with preserved ejection fraction (HFpEF), from those with WHO group 1 pulmonary arterial hypertension (PAH) is challenging. Separating the two conditions is of vital importance because treatment strategies differ completely. Furthermore, therapies that are indicated for WHO group 1 PAH may be harmful in patients with WHO group 2 PH. We review the somewhat confusing PH nomenclature and the WHO classification system and rationale behind it. We then focus on left-side heart disorders that cause PH. An aging population and advances in the medical management of common cardiovascular disorders have caused the prevalence of heart failure to rise significantly, with more than one-half of patients having HFpEF. We review contemporary studies that focus on clinical and echocardiographic findings that help to distinguish HFpEF from PAH in the patient with PH. We discuss the typical, and sometimes atypical, hemodynamic profiles that characterize these two groups, review challenges in the interpretation of data obtained by right-sided heart catheterization, and highlight special maneuvers that may be required for accurate diagnosis. Finally, we review the largely disappointing studies on the use of PAH-specific therapies in patients with WHO group 2 PH, including the use of prostacyclins, endothelin receptor antagonists, and the more promising phosphodiesterase-5 inhibitors.

Pulmonary Arterial Capacitance Is an Important Predictor of Mortality in Heart Failure With a Preserved Ejection Fraction

“…Continuous variables were summarized using means and standard deviations (7) or medians and interquartile range. Categorical variables were summarized using frequencies and proportions.…”

“…PH-LHD, also termed Group 2 PH, is defined by a mean pulmonary artery pressure (mPAP) ≥25 mm Hg and a pulmonary artery wedge pressure (PAWP) or left ventricular end-diastolic pressure >15 mm Hg (1,6). Patients with PH-LHD exhibit variable pulmonary vascular phenotypes with some individuals manifesting a “disproportionate” increase in mPAP relative to PAWP and others demonstrating a “proportionate” pressure rise, a distinction previously defined by a transpulmonary gradient (TPG) of >12 mm Hg or ≤12 mm Hg, respectively (6,7). According to experts at the Fifth World PH Symposium, these 2 groups are better discriminated by the diastolic pressure gradient (DPG) with DPG ≥7 mm Hg and <7 mm Hg to refer to those with combined post-capillary and pre-capillary PH (Comb-PH) and isolated post-capillary PH (Iso-PH), respectively (8).…”

Saudi Guidelines on the Diagnosis and Treatment of Pulmonary Hypertension: Pulmonary hypertension due to left heart disease

“…[1] Although, the overall prevalence of PH due to LHD is unclear and varies according to the definition and diagnostic methods, WHO Group 2 PH is the most common cause of elevated pulmonary artery pressure (PAP). [2] Historically, mitral valve disease has probably been the best-described cause of PH.…”

Pulmonary hypertension: Classification and pathobiology

“…Much confusion is encountered in clinical practice with this nomenclature. Group 2 summarises pulmonary hypertension due to pathologies of the left heart [13,14], while the pressure elevation in group 3 is caused by diseases of the lung. These two groups in clude the most prevalent aetiologies for pulmonary hy pertension, although exact epidemiological data do not exist.…”