Pulmonary Vascular Disease Section
Restoration of RV function in PAH: Is it the holy grail to improve mortality and long-term outcomes?
Despite several therapeutic advances, PAH continues to be associated with high mortality. Even mild increases in mean pulmonary arterial pressure (mPAP) have been shown to directly impact outcomes (Maron BA, et al. Circulation. 2016 Mar 29;133[13]:1240), leading to a change in the hemodynamic definition of PAH (mPAP > 20 mm Hg) at the 2018 World Symposium on Pulmonary Hypertension (WSPH) (Galiè N, et al. Eur Respir J. 2019;53[1]:1801889). The WSPH also recommended a more aggressive and proactive approach to move patients to “low-risk” status.
Dr. Vijay Balasubramanian
Elevated mPAP results in increased RV afterload with subsequent RV dysfunction and consequent abnormal remodeling, which is associated with poor outcomes. Reversal of RV remodeling has been demonstrated in patients after PEA for CTEPH and/or lung transplantation for PAH (D’Armini AM, et al. J Thorac Cardiovasc Surg. 2007;133:162).
Dr. Jean M. Elwing
Aggressive mPAP reduction facilitates RV recovery, which may alter the course of PAH in the form of improved survival. RV dysfunction is mainly attributed to afterload mismatch and uncoupling of the RV. Although oral therapies have shown significant improvements in symptoms, functional class, and delaying clinical worsening, normalization of RV size and function is often not achieved. More aggressive reduction of mPAP with a combination of parenteral and oral therapies has been shown to be more effective in restoring RV function (Vizza CD, et al. Am J Respir Crit Care Med. 2022;205) with the ultimate goal of improving quality and quantity of life in those affected by PAH.
Vijay Balasubramanian, MD, FCCP, Chair
Jean M. Elwing, MD, FCCP, Ex-Officio