Background: The plasma volume status (PVS) is a marker of non-overt cardiac congestion and is of prognostic value. Patients with low-flow low-gradient (LFLG) aortic stenosis (AS) suffer from impaired left ventricular function and show signs of heart failure (HF). We hypothesized that the PVS might predict post-interventional rehospitalization and cardiovascular mortality in high-risk patients undergoing transcatheter aortic valve implantation (TAVI).

Methods: In this retrospective single-center analysis of n=2458 patients,PVS before transfemoral TAVI was calculated by a formula taking into account the patients’ hematocrit and weight. The predictive performance of PVS was compared with that of prior cardiac decompensation (PCD).

Results:In the entire cohort, a PVS > -4% (high plasma volumes) identified patients (n=1013) with higher cardiovascular risk and a higher post-interventional one-year mortality rate than patients (n=1445) with a PVS ≤ -4% (low plasma volumes). However, PVS lost prognostic independence when adjusted for anemia, whereas PCD did not. PVS and PCD were not correlated. The two parameters similarly revealed a low sensitivity and specificity but a high negative predictive value for the prediction of HF events. PVS was not different between control patients (n=1512) and those with intermediate (paradoxical LFLG-AS, n=327) or high risk (LFLG-AS, n=239). The accuracy of a high PVS in predicting adverse events in these subpopulations was the same as in the overall population. Kaplan-Maier survival analyses demonstrated the same prognostic impact for the PVS and PCD. 

Conclusions: Non-overt (PVS) and overt (PCD) cardiac congestion represent two independent parameters of volume overload with unfavorable prognostic significance. The pre-interventional PVS does not appear to be suitable for predicting clinical outcomes in high-risk patients undergoing TAVI.