Prognostic Value of Preoperative Pulmonary Arterial Capacitance for Patients Undergoing Aortic Valve Replacement for Severe Aortic Valve Stenosis

Background: Pulmonary arterial capacitance (PAC) is a determinant of right ventricular afterload and a strong independent predictor of unfavorable outcomes in advanced heart failure (HF) with pulmonary hypertension (PH). We aimed to test the hypothesis that preoperative PAC may affect postoperative clinical outcomes in patients undergoing aortic valve replacement (AVR) for severe aortic valve stenosis (AS), even in the absence of PH. Methods and Results: We studied 116 patients who underwent AVR for severe AS between January 2005 and December 2017. Right heart catheterization was performed for all patients prior to surgery. PAC and pulmonary vascular resistance (PVR) fit well to a hyperbolic relationship (PAC=0.23/PVR, R-2=0.73). PAC also showed an inverse relationship with pulmonary capillary wedge pressure (PCWP) (r=-0.15) and mean pulmonary arterial pressure (r=-0.29) and provided a stronger prediction of death or HF admission than PCWP or PVR (area under the ROC curve of 0.74 vs. 0.40 and 0.41, respectively, P=0.002). During a median follow-up of 36 months, PAC (hazard ratio, 0.48; 95% confidence interval, 0.30-0.78; P=0.003) was an independent predictor of death or hospitalization for HF. Conclusions: In these patients undergoing AVR for severe AS, even in the absence of PH, preoperative reduced PAC was independently associated with adverse surgical outcomes. It seems that preoperative PAC has potential as an independent predictor of long-term prognosis after AVR for severe AS.