Yoshio Kazuno

Comparison of SAPIEN 3 and SAPIEN XT transcatheter heart valve stent-frame expansion: evaluation using multi-slice computed tomography

Aims Stent-frame morphology of the newer-generation, balloon-expandable transcatheter heart valve (THV), the SAPIEN 3 (S3), after transcatheter aortic valve implantation (TAVI) is unknown. We evaluated the THV stent-frame morphology post TAVI of the S3 using multi-slice computed tomography (MSCT) compared with the prior-generation THV, SAPIEN XT (S-XT). Methods and results A total of 94 consecutive participants of RESOLVE registry (NCT02318342) had MSCT after balloon-expandable TAVI (S3 = 39 and S-XT = 55). The morphology of the THV stent-frame was evaluated for expansion area and eccentricity at the THV-inflow, native annulus, mid-THV and THV-outflow levels. Mean %-expansion area for the S3 and the S-XT was 100.9 ± 5.7 and 96.1 ± 5.5%, respectively (P < 0.001). In the S3 group, the THV-inflow level had the largest value of %-expansion area, which decreased from THV-inflow to mid-THV level (105.2 ± 6.4 to 96.5 ± 5.9%, P < 0.001). However, in the S-XT group, %-expansion area increased from THV-inflow level to mid-THV level (93.2 ± 6.2 to 95.1 ± 6.1%, P = 0.0058). On nominal delivery balloon volume, the S3 in 88.5% of cases had overexpansion at the THV-inflow level. The observed degree of THV oversizing of the S3 was significantly lower than the S-XT (6.3 ± 8.6 vs. 11.8 ± 8.5%, P = 0.0027). Nonetheless, the incidence of post-procedural paravalvular aortic regurgitation (PVR) ≥ mild following the S3 TAVI was also significantly lower than the S-XT TAVI (17.9 vs. 43.6%, P = 0.014). Conclusion The newer-generation, balloon-expandable device, the S3, has a flared inflow morphology, whereas the prior-generation device, the S-XT, has relatively constrained inflow morphology post TAVI. This may contribute to a lesser degree of PVR with the S3.

Clinical impact of coronary protection during transcatheter aortic valve implantation: first reported series of patients.

AIMS Coronary protection with guidewires and an undeployed coronary balloon or stent positioned in the coronary artery is a pre-emptive technique to manage coronary obstruction during transcatheter aortic valve implantation (TAVI). We investigated the feasibility and safety of left main (LM) protection during TAVI. METHODS AND RESULTS Twenty-five out of 623 patients who underwent TAVI at our institute were deemed to be at increased risk of LM compromise mainly due to a low LM ostium height, significant LM disease or a previous bioprosthetic valve. A pre-emptive LM protection technique was therefore used in these cases. Five patients (20%) had pre-TAVI significant non-revascularised LM stenosis, and four patients (16%) had a prior LM ostial stent without pre-TAVI in-stent restenosis. Twelve patients had extremely low LM height (mean height 6.7±2.4 mm; range 1.1-8.9 mm). Seven patients (25%) had valve-in-valve (VIV) procedures. LM compromise occurred in five out of 25 cases; all were treated successfully with emergency LM stenting. Nine patients underwent successful planned LM procedures following TAVI. CONCLUSIONS The LM protection technique should be considered in patients deemed to be at increased risk of LM compromise. This was found to be helpful in the prompt diagnosis and treatment of LM compromise following TAVI.

Natural history of subclinical leaflet thrombosis affecting motion in bioprosthetic aortic valves

Aims Four-dimensional volume-rendered computed tomography (4DCT) has demonstrated instances of hypo-attenuating leaflet thickening (HALT) with or without hypo-attenuation affecting motion (HAM) after transcatheter and surgical aortic valve implantation (TAVI, SAVR). The temporal pattern of evolution of these phenomena is uncertain. Methods and results The SAVORY registry enrolled patients treated by TAVI (n = 75) or SAVR (n = 30) with two 4DCT scans fully interpretable for HALT and HAM as well as unchanged anti-thrombotic medication between the scans. Logistic regression analysis was performed to examine the evolution of HALT and HAM while accounting for demographic and baseline variables, timing of both CT scans, valve type and antithrombotic therapy. The analysis population consisted of 84 patients, in whom first and second CT scans were performed at 140 ± 152 days and 298 ± 141 days after valve implantation, respectively. Hypo-attenuating leaflet thickening was noted in 32 patients (38.1%), with HAM in 17 (20.2%). Both findings were dynamic, showing progression in 13 (15.5%) and regression and 9 (10.7%) patients. Compared with antiplatelet therapy, progression was less likely among patients on oral anticoagulation with vitamin-K antagonists or non-VKA oral anticoagulants (odds ratio: 0.014, P = 0.036). Maintenance on chronic oral anticoagulation was not a significant predictor of regression. These findings were similar for both transcatheter and surgical bioprosthetic aortic valves. No patients developed symptoms of valve dysfunction and leaflet thickening was not clearly associated with any clinical events. Conclusions Subclinical leaflet thrombosis is a common finding after TAVI and SAVR, and may progress from normal leaflet over HALT to the more severe HAM. The phenomenon can develop and regress at variable intervals after valve implantation. Anticoagulants may have a protective effect against the development of HALT, but HALT can also regress without anticoagulation therapy. Registered at ClinicalTrials.gov NCT02426307.

Concomitant mitral annular calcification and severe aortic stenosis: prevalence, characteristics and outcome following transcatheter aortic valve replacement

Aims Calcified aortic stenosis (AS) and mitral annular calcification (MAC) have certain similar etiology and pathophysiological mechanisms. MAC is frequently encountered in pre-procedural computed tomography (CT) imaging of patients that undergo transcatheter aortic valve replacement (TAVR), but its prognostic implications for these patients have not been thoroughly investigated. This study sought to evaluate the prevalence of MAC among patients with severe AS and to assess the clinical implications of MAC on these patients during and following TAVR. Methods and results Consecutive patients that underwent TAVR were compared according to the existence of MAC and its severity in pre-TAVR CT scans. From the entire cohort of 761 patients, 49.3% had MAC, and 50.7% did not have MAC. Mild MAC was present in 231 patients (30.4%), moderate MAC in 72 patients (9.5%), and severe MAC in 72 patients (9.5%). Thirty-day mortality and major complications were similar between patients with and without MAC. In a multivariable survival analysis, severe MAC was found to be an independent strong predictor of overall mortality following TAVR (all-cause mortality: hazards ratio [HR] 1.95, 95% confidence interval [CI] 1.24–3.07, P = 0.004; cardiovascular mortality: HR 2.35, 95% CI 1.19–4.66; P = 0.01). Severe MAC was also found to be an independent strong predictor of new permanent pacemaker implantation (PPI) after TAVR (OR 2.83, 95% CI 1.08–7.47; P = 0.03). Conclusion Half of the patients with severe AS evaluated for TAVR were found to have MAC. Severe MAC is associated with increased all-cause and cardiovascular mortality and with conduction abnormalities following TAVR and should be included in future risk stratification models for TAVR.

Optimal sizing for SAPIEN 3 transcatheter aortic valve replacement in patients with or without left ventricular outflow tract calcification

AIMS The impact of left ventricular outflow tract calcification (LVOT-CA) on SAPIEN 3 transcatheter aortic valve replacement (S3-TAVR) is not well understood. The aims of the present study were to determine optimal device sizing for S3-TAVR in patients with or without LVOT-CA and to evaluate the influence of residual paravalvular leak (PVL) on survival after S3-TAVR in these patients. METHODS AND RESULTS This study analysed 280 patients (LVOT-CA=144, no LVOT-CA=136) undergoing S3-TAVR. Optimal annular area sizing was defined as % annular area sizing related to lower rates of ≥mild PVL. Annular area sizing was determined as follows: (prosthesis area/CT annulus area-1)×100. Overall, ≥mild PVL was present in 25.7%. Receiver operating characteristic curve analysis for prediction of ≥mild PVL in patients with LVOT-CA showed that 7.2% annular area sizing was identified as the optimal threshold (area under the curve [AUC] 0.71). Conversely, annular area sizing for no LVOT-CA appeared unrelated to PVL (AUC 0.58). Aortic annular injury was seen in four patients (average 15.5% annular area oversizing), three of whom had LVOT-CA. Although there was no difference in one-year survival between patients with ≥mild PVL and without PVL (log-rank p=0.91), subgroup analysis demonstrated that patients with ≥moderate LVOT-CA who had ≥mild PVL had lower survival compared to patients with ≥mild PVL and none or mild LVOT-CA (log-rank p=0.010). CONCLUSIONS In the setting of LVOT-CA, an optimally sized S3 valve is required to reduce PVL and to increase survival following TAVR.

Relation Between Left Ventricular Outflow Tract Calcium and Mortality Following Transcatheter Aortic Valve Implantation

Left ventricular outflow tract (LVOT) calcium is known to be associated with adverse procedural outcomes after transcatheter aortic valve implantation (TAVI), yet its effect on midterm outcomes has not been previously investigated. The aim of this study was to determine the influence of LVOT calcium on 2-year mortality after TAVI. A total of 537 consecutive patients underwent TAVI and 2 groups were established, stratified based on the severity of the LVOT calcium. The primary outcome was 2-year overall survival rate. The ≥moderate LVOT calcium group included 107 patients (19.9%) and the remaining 430 patients (80.1%) were included in the ≤mild LVOT calcium group. After a median follow-up of 717 days (interquartile range 484 to 828), the Kaplan-Meier analysis revealed that the 2-year overall survival probability was significantly lower in the ≥moderate LVOT calcium group than in the ≤mild LVOT calcium group (log-rank p = 0.001). On a Cox hazard model, ≥moderate LVOT calcium was associated with increased all-cause mortality after TAVI (hazard ratio 1.74, p = 0.009). In the subgroup analysis, based on valve designs, SAPIEN 3-TAVI done in the setting of ≥moderate LVOT calcium had a relatively similar survival probability as those of ≤mild LVOT calcium (log-rank p = 0.18), which is in contrast with older generation valves (log-rank p = 0.001). In conclusion, patients with ≥moderate LVOT calcium were shown to have a lower survival probability in the midterm follow-up after TAVI, compared with those with ≤mild LVOT calcium. Patients with high-grade LVOT calcium should be monitored with longer-term follow-ups after TAVI.

Severe aortic stenosis with low aortic valve calcification: characteristics and outcome following transcatheter aortic valve implantation

Aims High aortic valve calcification (AVC) assessed with CT may be used to differentiate between severe and non-severe aortic stenosis (AS). Nonetheless, in some cases patients with low calcification are diagnosed with haemodynamically severe AS. The prevalence, mechanism of valve stenosis and implications for transcatheter aortic valve implantation (TAVI) of low AVC severe AS remain unclear. We assessed the clinical and haemodynamic characteristics and the outcome of patients with severe AS and low AVC that undergo TAVI. Methods and results Ninety-three patients that had low CT aortic valve calcification score (AVCS) were compared to 470 patients with high AVCS. High gradient severe AS was found among 53.8% (50/93) of the patients with low AVCS vs. 86% (404/470) of the patients with high AVCS (P < 0.001). Device success rate was similar between both groups. There were significantly lower rates of postprocedural paravalvular regurgitation (PVR) in the low AVCS group (≥ mild PVR: 12.9% vs. 23.6%; P = 0.03). Overall, there were only two cases (0.4%) of valve embolization in patients with high AVCS and 1 (1.1%) in patients with low AVCS (P = 0.42). Thirty-day mortality and major complications were similar between groups. Conclusion Balloon-expandable TAVI in patients with a mildly calcified aortic valve was not associated with increased risk of valve embolization or mortality. We demonstrated high device success and lower rates of PVR for these patients. These findings suggest that in patients with evidence of haemodynamically severe AS at echocardiography, the presence of low ACVS at CT should not preclude the consideration of TAVI.

Effect of ascending aortic dimension on acute procedural success following self-expanding transcatheter aortic valve replacement: A multicenter retrospective analysis

AIMS Self-expanding (SE) valves are characterized with long stent frame design and the radial force of the device exists both in the inflow and outflow level. Therefore, we hypothesized that device success of SE-valves may be influenced by ascending aortic dimensions (AAD). The aim of this study was to determine the influence of AAD on acute device success rates following SE transcatheter aortic valve replacement (TAVR). METHODS & RESULTS In 4 centers in the United States and Asia, 214 consecutive patients underwent SE-TAVR. Outcomes were assessed in line with Valve Academic Research Consortium criteria. AAD was defined as the sum of the short and long axis aortic diameter divided by 2. Overall, device success rate was 85.0%. Multivariate analysis revealed that increased AAD (Odds ratio 1.27) and % oversizing (Odds ratio 0.88) were found to be independent predictors of unsuccessful device implantation. The c-statistic of the model for device success was area under the curve 0.79, sensitivity 81.3% and specificity 44.0%. Co-existence of several risk factors was associated with an exponential fall to 64.2% in device success rate. For a large AAD, however, optimally oversized SE-valves (threshold 16.2%) resulted with high device success rates compared to suboptimal oversizing (88.6% vs. 64.2%, p=0.005). CONCLUSIONS Larger AAD and smaller degrees of oversizing were confirmed to be the most relevant predictors of unsuccessful device implantation following SE-valve implantations. Optimal oversizing of great significance was noted, particularly that with a large AAD.

Transcatheter Aortic Valve Replacement With Different Valve Types in Elliptic Aortic Annuli

BACKGROUND The aim of this study was to determine the influence of an elliptic annulus on acute device success rates following self-expanding (SE) transcatheter aortic valve replacement (TAVR) vs. balloon-expandable (BE) TAVR.Methods and Results:Outcomes were assessed using Valve Academic Research Consortium-2 definitions. Aortic annulus ratio (AAR) was measured as short axis diameter/long axis diameter. Mean AAR was 0.81±0.06. Patients were therefore divided into 2 groups: AAR <0.82 and AAR ≥0.82. For circular annuli (AAR ≥0.82; 363 patients), high device success rates were achieved in both valve groups (SE valve, 90.5% vs. BE valve, 95.0%, P=0.14). Conversely, for AAR <0.82 (374 patients), SE valves had lower device success rates than BE valves (82.5% vs. 95.3%, P=0.002). For elliptic annuli, SE-TAVR was an independent predictor of unsuccessful device implantation (OR, 6.34, P<0.001). Nonetheless, increased oversizing of SE valves for elliptic annuli was associated with an exponential rise in device success (threshold ≥17.5%; area under the curve, 0.83) but not for BE-TAVR. Furthermore, optimally oversized SE valves and BE valves had a similarly high device success for elliptic annuli (SE valve, 96.2% vs. BE valve, 95.3%). CONCLUSIONS For circular annuli, similarly high device success was achieved for the 2 valve types. Conversely, for elliptic annuli, SE valves had a lower device success than BE valves. Device success following optimal oversizing of SE valves, however, was similar to that for BE valves.

Computed tomography characteristics of the aortic valve and the geometry of SAPIEN 3 transcatheter heart valve in patients with bicuspid aortic valve disease

Aims We assessed the geometry of transcatheter heart valve (THV) and valve function associated with SAPIEN 3 implantation in patients with bicuspid aortic valve (BAV) stenosis. Methods and results We included 280 consecutive patients who had a contrast computed tomography (CT) before and after transcatheter aortic valve implantation (TAVI) in our institution. Each THV was assessed by CT at five cross-sectional levels: inflow, annulus, mid, sinus, and outflow. The geometry of THV was assessed for eccentricity (1 - minimum diameter/maximum diameter) and expansion (CT derived external valve area/nominal external valve area). CT measurements and transthoracic echocardiogram data were compared between BAV and tricuspid aortic valve (TAV). Among 280 patients, 41 patients were diagnosed as BAV. Compared to TAV, BAV was associated with lower expansion at mid-level, sinus-level, and outflow-level (mid 94.1 ± 6.8% vs. 98.1 ± 7.8%; P = 0.002, sinus 95.9 ± 7.2% vs. 101.6 ± 8.5%; P < 0.001, outflow 107.6 ± 6.2% vs. 109.9 ± 6.6%; P = 0.043), and higher eccentricity at all levels [inflow 3.5% (1.9-5.3) vs. 6.0% (3.2-7.5); P < 0.001, annulus 3.1% (1.6-5.2) vs. 5.4% (3.1-7.8); P = 0.002, mid 3.0% (1.4-4.9) vs. 6.0% (3.3-10.4); P < 0.001, sinus 3.0% (1.7-5.1) vs. 7.6% (4.0-11.4); P < 0.001, and outflow 2.5% (1.3-4.3) vs. 4.9% (2.2-7.5); P < 0.001]. There were no differences in frequency of paravalvular leak ≥ moderate and mean post-procedural gradient between BAV and TAV. Conclusion BAV patients have greater THV eccentricity at all levels and lower THV expansion at mid, sinus, and outflow levels than the TAV patients. There were no differences in parameters of valve function between BAV and TAV patients. Despite the observed geometrical differences, TAVI with SAPIEN 3 in BAV patients allows for feasible valve function.