Immediate and Long-term Echocardiographic Outcomes
The mean preoperative pressure gradients were significantly elevated (dPmean 41.3 ± 15.3 mmHg) as consequence of stenosis as predominant mode of failure (n=68/77; 88.3%).
All patients with preoperative stenotic bioprosthesis experienced a significant reduction of their transvalvular pressure gradients after successful TAVR, as confirmed by predischarge transthoracic echocardiography (dPmean 16.8 ± 7.1 mmHg; p<0.01; Figure 2A ). This was independent from the inner diameter of the degenerated valve (Figure 2B ).
Median postprocedural mean transvalvular pressure gradient was 18.0 mmHg with an interquartile range from 12.0 to 23.5 mmHg. None of the patients had a mean postprocedural pressure gradient above 40 mmHg postoperatively. Initial device success according to VARC-2 criteria was achieved in 62.3% (n=48/77) of the cases (Figure 3 ). The overall low success-rate was driven by mean transvalvular pressure gradients, exceeding 20mmHg in 37.7% (n=29/77) of the patients. Hereby, patients with a true-ID equal or less 21mm had significant less primary device success compared to patients with a larger true-ID (48.9% [n=22/45] vs. 81.3% [n=26/32] p=0.0299). Residual paravalvular leakage was infrequent (n=6/77;7.8%). None of the residual PVL were larger than trace.
During further follow-up transvalvular pressure gradients steadily increased and correspondingly the device success rate decreased (Figure 2 and 3) . After 3-years, only 28.6% (n=22/77) of the patients had persisting device success according to VARC-2 criteria. Mean Vmax was 317 ± 76 cm/sec (Median 280 cm/sec) with a dPmean averaging 26.0 ± 12.2 mmHg (Median 24 mmHg) after three years of follow-up (Table 3; Figure 2A ). This observation was particularly true for internal diameters less or equal 21mm – after an initial significant reduction, the mean transvalvular gradients remained significantly increased (Figure 2B ).
Additionally, the trend of steadily deteriorating hemodynamic performance during follow-up was independently from the type of prosthesis. Despite self-expandable prostheses having a significant higher rate of initial device success compared to balloon-expandable valves (69.2% vs. 56.3%; p=0.047), this observation turned after 3 years with balloon-expandable THV now having a significantly higher rate of persisting device success (36.3% vs. 21.4%, p=0.041) (Figure 3 ).