The Prognostic Value of Right Ventricular Function in Pulmonary Arterial Hypertension

Kober Alexander^*
*Correspondence: Kober Alexander, Department of Respiratory Care, University of Warmia and Mazury, 10-719 Olsztyn, Poland, Email:

Introduction

Pulmonary Arterial Hypertension (PAH) is a serious and progressive disease characterized by an increase in mean pulmonary arterial pressure, which results from the construction and remodelling of pulmonary blood vessels. As the disease progresses, it leads to right heart failure and, ultimately, death if untreated. While the primary focus of research has traditionally been on understanding the mechanisms that drive pulmonary vasoconstriction and vascular remodelling in PAH, recent evidence has highlighted the crucial role that Right Ventricular (RV) function plays in the prognosis of these patients. The right ventricle, which is responsible for pumping blood into the pulmonary circulation, experiences increased workload as pulmonary arterial pressure rises in PAH. Over time, this results in right ventricular hypertrophy, dilation, and dysfunction. The relationship between RV function and survival outcomes in PAH has been increasingly recognized as an essential prognostic indicator. Several studies have shown that RV dysfunction, as measured by various imaging modalities and biomarkers, is strongly associated with poorer outcomes in PAH patients. This article explores the role of right ventricular function in PAH, the methods of assessing RV function, and the prognostic value it holds for patient survival and disease management [1].

Description

Pulmonary arterial hypertension is defined by a sustained increase in mean pulmonary artery pressure (mPAP) exceeding 25 mmHg at rest, as measured by right heart catheterization. The pathophysiology of PAH involves the gradual narrowing and remodeling of the small pulmonary arteries, which leads to increased pulmonary vascular resistance (PVR). As the disease progresses, the right ventricle is subjected to higher afterload due to the elevated pressure in the pulmonary circulation. In a healthy heart, the right ventricle is adapted to handle low-pressure blood flow to the lungs. However, when faced with elevated pulmonary pressures, the right ventricle must work harder to maintain an adequate blood flow. The right ventricle initially compensates for increased afterload by thickening its walls to generate more forceful contractions. This hypertrophy can delay the onset of symptoms but ultimately leads to a decline in function as the myocardial fibers become stiff and less compliant. As the pressure continues to increase, the right ventricle dilates in an attempt to accommodate the higher volume of blood. Over time, this dilation becomes progressive and often results in a decreased ability of the right ventricle to contract effectively [2]. These changes in RV function are central to the progression of PAH and are critical in determining the clinical outcome of affected patients. Right ventricular function is a pivotal determinant of both short- and long-term prognosis in PAH. In fact, RV dysfunction has been found to be a stronger predictor of mortality than pulmonary pressures or other hemodynamic variables alone. Understanding the mechanisms that underlie RV failure and the methods by which RV function can be assessed are crucial to determining the appropriate therapeutic strategies for managing PAH. The assessment of RV function is complex due to the unique anatomical and functional characteristics of the right ventricle. Several imaging techniques and hemodynamic measurements can be used to evaluate the performance of the right ventricle in PAH patients. Echocardiography is the most widely used imaging technique for assessing RV function. It allows for the measurement of right ventricular dimensions, wall thickness, and the assessment of systolic function through parameters like Tricuspid Annular Plane Systolic Excursion (TAPSE) and Right Ventricular Fractional Area Change (RVFAC). Doppler imaging can also assess right ventricular outflow tract velocity and pulmonary artery pressure, both of which are crucial in evaluating the impact of PAH on the right ventricle. Cardiac Magnetic Resonance (CMR) Imaging provides a more detailed and accurate assessment of right ventricular size, function, and myocardial strain. CMR can measure right ventricular volumes, Ejection Fraction (EF), and myocardial fibrosis, offering insights into the structural and functional changes occurring in PAH. CMR has the advantage of being noninvasive and provides an ideal method to assess RV function over time [3]. Several studies have demonstrated that right ventricular dysfunction is a key prognostic factor in PAH. The severity of RV dysfunction is strongly associated with survival rates, and its early detection can help clinicians predict disease progression and tailor treatment strategies. A decrease in RVEF is one of the most important markers of RV dysfunction in PAH. Studies have shown that a reduction in RVEF is independently associated with worse survival outcomes. Recent advancements in imaging technology have allowed for the measurement of right ventricular strain, a marker of myocardial deformation. Strain imaging, particularly through CMR, provides an accurate representation of RV myocardial performance. Reduced RV strain has been shown to predict adverse clinical outcomes in PAH, including progression to right heart failure. Right heart catheterization allows for the measurement of Right Atrial Pressure (RAP) and cardiac output. Elevated RAP, indicative of increased RV afterload, correlates with RV dysfunction and poor survival. Additionally, a low Cardiac Index (CI) is also associated with adverse outcomes in PAH, as it reflects an inability of the right ventricle to meet the body’s circulatory demands [4,5].

Conclusion

Right ventricular function plays a pivotal role in the prognosis of patients with pulmonary arterial hypertension. The progressive nature of PAH leads to increased pulmonary pressures, which directly affect the right ventricle's ability to function. Early detection of RV dysfunction through advanced imaging techniques, biomarkers, and hemodynamic assessments is critical for identifying patients at risk of poor outcomes. Monitoring RV function throughout the course of the disease provides valuable insights into disease progression and helps guide treatment strategies. In particular, RV dysfunction is now recognized as one of the most reliable prognostic indicators in PAH, and efforts to preserve or improve RV function are central to improving patient survival. As research into the pathophysiology of PAH continues, further understanding of the relationship between right ventricular function and disease progression will enhance our ability to manage this complex and lifeAlexander threatening condition effectively.

Acknowledgement

None

Conflict of Interest

None

References

1. Hoette, Susana, Nicolas Creuzé, Sven Günther and David Montani, et al. "RV fractional area change and TAPSE as predictors of severe right ventricular dysfunction in pulmonary hypertension: A CMR study."Lung196 (2018): 157-164.

Google Scholar, Crossref, Indexed at

2. Sachdev, Arun, Hector R. Villarraga, Robert P. Frantz and Michael D. McGoon, et al. "Right ventricular strain for prediction of survival in patients with pulmonary arterial hypertension."Chest139 (2011): 1299-1309.

Google Scholar, Crossref, Indexed at