01 March 2017 by Bahri Akdeniz

The prognostic value of Qp/Qs ratio in pulmonary hypertension patients without left-to-right shunts

Introduction

Pulmonary to systemic flow ratio (Qp/Qs) is a hemodynamic parameter which is used to determine the significance of left-to-right shunts in congenital heart diseases. In patients with pulmonary hypertension (PH), Qp/Qs ratio decreases due to increased pulmonary artery pressures (PAP), and right ventricular dysfunction. In this study we aimed to investigate the prognostic value of Qp/Qs in predicting survival in PH patients without L-R shunt. 

Material and method

In this prospective study of 116 consecutive PH patients without a left-to-right shunt, clinical and hemodynamic parameters were recorded at initial diagnosis. Baseline hemodynamic data including pulmonary artery pressures (PAP), pulmonary vascular resitance (PVR), cardiac index (CI), right atrial pressure (RAP) and Qp/Qs ratio were obtained. The prognostic values of baseline catheterization parameters were analyzed by Cox regression model.

Results

In a mean follow-up of 36.months, 42 deaths occurred. On Cox regression analysis, among baseline hemodynamic parameters only Qp/Qs ratio (HR: 2.949   95% CI: 1.046- 8.333 p=0.04)  and RAP ( HR: 1.091  95%CI: 1.042-1.142 p<0.001) significantly predicted mortality (Table 1). When the correlation between Qp/Qs and other well known prognostic variables were analyzed,  BNP, 6 minute walking distance and TAPSE did not significanly correlate with Qp/Qs ratio. However baseline functional capacity (r:-0.236  p: 0.023), sPAPRHC (r:-0.229  p:0.025), and PVR (r: -0.270  p:0.008) were all negatively correlated with Qp/Qs ratio.

Conclusion

Decreased Qp/Qs ratio is associated with mortality in PH. Qp/Qs ratio may be a useful parameter in predicting severity of the disease  and  also survival in PH patients without left-to-right shunt.

Key Contributors

* Ebru Özpelit, Nezihi Barış, **Can Sevinç, ***Dilek Sezgin, **Kermal Can Tertemiz *Department of Cardiology, **Chest Medicine Dokuz Eylul University School of Medicine *** Dokuz Eylul University Faculty of Nursing Izmir


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