P1638Impact of left ventricular and aortic valve characteristics on one-year mortality of patients with low-flow low-gradient aortic valve stenosis after transcatheter aortic valve implantation (TAVI)

Abstract

Background: Patients with severe aortic valve stenosis (AS), low transvalvular gradients (Pmean) and depressed left ventricular (LV) systolic function are characterised by higher overall morbidity than other patients with AS. Purpose: We aimed to analyse the impact of parameters of LV function and characteristics of aortic valve disease before TAVI on the mid‐term outcome after TAVI. In particular, we examined whether latent LV functional capacity, unmasked by LV contractile reserve, can predict the survival of these patients. Methods: This study was designed as a retrospective landmark analysis of TAVI patients from the day of discharge to the time point of completion of the oneyear follow‐up. 34 patients (79% male) with low‐flow low‐gradient AS [aortic valve area <0.6 cm2/m2, Pmean <40 mmHg, stroke volume (SV) <35 ml/m2, ejection fraction (EF) <50%] received a comprehensive echocardiographic examination before TAVI, including low‐dose dobutamine stress testing. Results: Mortality one year after TAVI was 32% (n=11, 100% male). Age (79.7±4.0 vs. 77.5±7.3 years; p=0.36), glomerular filtration rate (54±23 vs. 59±21 ml/min/1.73m2; p=0.53), the incidence of diabetes (p=0.41), coronary artery disease (p=0.47), prior myocardial infarction (p=0.61), and prior cardiac surgery (p=0.52) or stroke (p=0.35) were not different between non‐survivors and survivors. Non‐survivors tended to have a higher EUROscore II (14.0±11.4 vs. 8.0±6.7%; p=0.07). LV mass (131±24 vs. 138±44 g/m2; p=0.70), Pmean (18.5±5.6 vs. 19.4±4.8 mmHg; p=0.64), and aortic valve area (0.48±0.08 vs. 0.47±0.10 cm2/m2; p=0.69) were not different between groups. While the EF tended to be lower in non‐survivors (27.5±8.6 vs. 34.5±9.7%; p=0.05), SV was similar between groups (24.7±5.6 vs. 25.2±5.3 ml/m2; p=0.79). The LV contractile reserve did not differ between non‐survivors and survivors (26.7±15.7 vs. 31.5±20.5; p=0.50), but the stress‐induced increase in transvalvular flow tended to be higher in survivors (46.5±22.2 vs. 68.0±37.2 ml/s; p=0.09). The Agatston mean calcium score was slightly higher in non‐survivors than in survivors (1942±841 vs. 1396±605; p=0.05). We determined the area under the curve (AUC) of the receiver‐operating characteristic (ROC) curve to evaluate the test performance of parameters with borderline significance as a predictor of mortality after TAVI. Only the Agatston score (AUC of 0.72, 95% CI 0.52 ‐ 0.92; p=0.048) emerged as a useful predictor of one‐year mortality, whereas EF (AUC of 0.32) and the increase in transvalvular flow (AUC of 0.28) did not. Conclusions: In our patients with low‐flow low‐gradient AS, parameters of LV function or LV contractile reserve or hemodynamic characteristics of AS had no predictive value for one‐year mortality after successful TAVI. Only the degree of aortic valve calcification emerged as a marker, which may potentially be useful to estimate the mid‐term risk in these patients.