Page 25 - Journal of Structural Heart Disease Volume 5, Issue 6

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Original Scientific Article
CoreValveTM EvolutTM R System, with a more secure seal protecting against PVL [3, 4]. The latest iteration of this self-expandable valve is named the Evolut Pro system [1]. Based on the prior EvolutTM R platform, this novel valve consists of an external pericardial wrap that ensures a reduction in PVL while retaining other benefits of the previous generation, including a low delivery profile, self-expansion, as well as its ability to recapture and reposition the valve.
The efficacy of the Evolut PRO design has been initially tested by the investigators of the Evolut PRO clinical study [5], conducted as a non-randomized, single-arm prospective registry at eight centers in the USA including a total of sixty well-selected patients. These patients were prospectively followed over 30 days with a primary efficacy endpoint of none or trace aortic regurgitation. The study showed that the Evo- lutTM PRO system provided excellent hemodynamics and minimal residual aortic regurgitation. There are multiples studies that sought to assess PVL predic- tors based on anatomical characteristics (defined by computed tomography [CT]) [6-8]. Because EvolutTM PRO is a very new design, apart from the American study [5], there is no additional data available about its safety and efficacy in a “real life” clinical scenario. Moreover, the incidence and determinants of PVL af- ter TAVR with the CoreValveTM EvolutTM PRO remain un- known. We sought to assess predictors of PVL using this novel device.
Methods
Twenty-seven consecutive patients with severe symptomatic aortic stenosis (aortic valve area (AVA) <1 cm2 or indexed AVA <0.6 cm2/m2) undergoing transfemoral TAVI using the Medtronic CoreValveTM Evolut Pro bioprosthesis between October 2017 and July 2018, were prospectively recruited. All patients were previously discussed in a dedicated Heart Team meeting involving cardiac surgeons, interventional cardiologists, experts in cardiac imaging and clinical cardiologists. Our clinical and anatomic selection cri- teria and device size selection were in accordance with previous recommendations [4]. The prosthesis sizing was based on a combination of echocardiographic and CT measurements but eventually remained at the discretion of the implanting interventional cardiolo-
gist. All patients underwent a pre-procedure CT and all images were systematically analyzed using a cardi- ac application on a dedicated workstation by two in- dependent experienced observers. The best diastolic images at 70 or 80% of the R-R interval were used. The largest (Dmax) and the smallest (Dmin) aortic annu- lus and left ventricle outflow tract (LVOT) diameters were measured. The mean diameter (Dmean) was de- rived by averaging the largest and smallest diameter. The circularity of aortic annulus was defined using the eccentricity index using the formula (1 – Dmin/ Dmax) [6]. The degree of aortic valve calcification was semi-quantitatively classified as no calcification, mild calcification (small calcium spots), moderate calcifi- cation (larger calcium spots), and severe calcification (extensive calcification) as previously described [7]. The “cover index”, expressed as a ratio of: ([prosthe- sis diameter – CT annulus diameter] / prosthesis di- ameter) x 100, was calculated to assess the congru- ence between the aortic annulus and the device [8]. Finally, to further explore the value of the difference between prosthesis size and annular size for the pre- diction of PVL, the difference between the nominal bioprosthesis size and mean CT aortic annulus diam- eter was assessed [9]. Following a predefined proto- col, pre-discharge transthoracic echocardiographic was obtained in all patients. PVL was systematically graded, by an independent experienced operator blinded to angiographic data and procedural results, using multiple parameters including regurgitation color jet density and width, circumferential extent of turbulent regurgitation color jet around the aortic annulus for PVL, descending and abdominal aorta diastolic flow reversal on pulsed wave Doppler, and pressure half- time of aortic regurgitation on contin- uous wave Doppler signal, as previously defined [10].
For data analysis patients were divided into two groups according to the presence of PVL: no or trace PVL versus mild or grade II PVL. The groups were com- pared to identify the demographic, echocardiograph- ic and CT parameters predictive of PVL. The data are expressed as the mean ± the standard deviation (SD). The differences between the means were calculated using Student’s t-test after assessing normality. The differences in categorical variables were analyzed using Chi-square tests. Univariate analysis was used to identify the most significant predictors of PVL. The
Alvarado Casas T. et al.
Paravalvular Leak Predictors Following TAVR