Do postoperative hemodynamic parameters add prognostic value for the prediction of mortality after surgical aortic valve replacement?

Abstract

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): The PERIGON Pivotal Trial was funded by Medtronic. Background While different parameters to assess prosthetic valve performance are available, prosthesis-patient mismatch (PPM) is exclusively based on indexed effective orifice area (EOAi). Purpose We investigated the prognostic value of multiple postoperative hemodynamic parameters, independent of the STS predicted risk of mortality (STS PROM), for prediction of 5-year mortality after surgical aortic valve replacement (SAVR). Methods The study population consisted of patients enrolled in a prospective multicenter study. All patients underwent SAVR with the same stented bioprosthesis. Patients who underwent previous open-heart surgery, or died or withdrew consent before echocardiographic assessment at their first follow-up visit (3–6 months), were excluded. Cox regression models were fitted to estimate the relation between STS PROM, postoperative hemodynamic parameters (as continuous variables except for PPM), and all-cause mortality. Follow-up started at the first postoperative outpatient clinic visit and continued until death or withdrawal from the study, whichever came first. In addition to the STS PROM, candidate predictors included peak aortic jet velocity (Vmax), mean pressure gradient (MPG), EOA, predicted and measured EOAi, Doppler velocity index (DVI), internal prosthesis orifice area indexed (POAi) by stroke volume, and Valve Academic Research Consortium (VARC) 3 categories for PPM (1). All echocardiograms were evaluated by a core laboratory. Although the STS PROM was initially developed to predict 30-day mortality (2), it has also been proven to predict late mortality (3). Model performance was investigated using the c-statistic, likelihood ratio test, and net reclassification improvement (NRI), among others. Results Among 1118 patients enrolled, 1022 patients were included in the study. Patients were on average 70 years, 75% was male, and 88% had a left ventricle ejection fraction of ≥50%. At 5-year follow-up, 89 patients had died, and the median follow-up time was 1697 days. In univariate analysis, STS PROM was the only significant predictor of 5-year mortality (hazard ratio 1.40, 95%-confidence interval [CI] 1.26, 1.55). Moreover, STS PROM performed best in terms of the c-statistic (0.66, 95%-CI 0.60, 0.72). When extending the STS PROM with single hemodynamic parameters (Table 1), neither the c-statistics nor the NRI demonstrated added prognostic value compared to a model with STS PROM alone. Similar findings were observed when multiple hemodynamic parameters were added to STS PROM (c-statistic 0.68, 95%-CI 0.62, 0.74, and NRI 0.04, 95%-CI −0.08, 0.16). Conclusions The STS PROM was found to be the main predictor of patients’ prognosis. In this analysis, the added prognostic value of postoperative hemodynamic parameters for 5-year mortality after SAVR was limited (Figure 1). These results warrant further research on the value of PPM, residual postoperative hemodynamic obstruction and their relation with adverse outcomes.