Temporal trends of frame expansion and paravalvular leak reduction after transcatheter aortic valve replacement with self-expandable prostheses.

BACKGROUND: Paravalvular leakage (PVL) is a common finding after transcatheter aortic valve replacement (TAVR) and affects late clinical outcome. It is more frequent with self-expandable (SE) transcatheter-heart-valve (THV). Few is known about SE-THV expansion after implantation. The purpose is to assess SE-THV frame expansion and its possible influence on PVL. METHODS: We designed a prospective pilot study to assess the time-course of SE-THV frame dimensions and PVL after TAVR. Consecutive patients undergoing TAVR with SE-THV were enrolled. Prosthesis fluoroscopy and echocardiography were prospectively performed immediately after TAVR (T0) and before discharge (T1) to grade PVL. Prosthesis diameters were assessed in 2 fluoroscopic orthogonal views. PVL reduction ≥1+ from T0 to T1 at echocardiography was the primary study endpoint. RESULTS: Twenty-five patients were enrolled. Mean interval between T0 and T1 evaluations was 5 days. Grade 1 or 2 was present in 76% of patients at T0 and in 68% at T1 (P=0.034). A total of 7 patients (28%) improved PVL ≥1 grade from T0 to T1. Differences between T0 and T1 fluoroscopic diameters were not statistically significant. When comparing the diameter changes according to PVL evolution, patients with PVL improvement (as compared with those without) had significantly larger minimum diameter increase at both annulus/inflow (P=0.016) and outflow/distal edge (P=0.027). CONCLUSIONS: PVL may improve in the early days after SE-THV and those patients with PVL improvement may have THV frame expansion. Further studies are needed to confirm such preliminary observations and to establish the clinical relevance of this phenomenon.

Configuration of two-stent coronary bifurcation techniques in explanted beating hearts: the MOBBEM study.

BACKGROUND: In patients with complex coronary bifurcation lesions undergoing percutaneous coronary intervention (PCI), various 2-stent techniques might be utilised. The Visible Heart Laboratories (VHL) offer an experimental environment where PCI results can be assessed by multimodality imaging. AIMS: We aimed to assess the post-PCI stent configuration achieved by 2-stent techniques in the VHL and to evaluate the procedural factors associated with suboptimal results. METHODS: Bifurcation PCI with 2-stent techniques, performed by expert operators in the VHL on explanted beating swine hearts, was studied. The adopted bifurcation PCI strategy and the specific procedural steps applied in each procedure were classified according to Main, Across, Distal, Side (MADS)-2 and to their adherence to the European Bifurcation Club (EBC) recommendations. Microcomputed tomography (micro-CT) was used to assess the post-PCI stent configuration. The primary endpoint was "suboptimal stent implantation", defined as a composite of stent underexpansion (<90%), side branch ostial area stenosis >50% and the gap between stents. RESULTS: A total of 82 PCI with bifurcation stenting were assessed, comprised of 29 crush, 25 culotte, 28 T/T and small protrusion (TAP) techniques. Suboptimal stent implantation was observed in as many as 53.7% of the cases, regardless of baseline anatomy or the stenting strategy. However, less frequent use of the proximal optimisation technique (POT; p=0.015) and kissing balloon inflations (KBI; p=0.027) and no adherence to EBC recommendations (p=0.004, p multivariate=0.006) were significantly associated with the primary endpoint. CONCLUSIONS: Commonly practised bifurcation 2-stent techniques may result in imperfect stent configurations. More frequent use of POT/KBI and adherence to expert recommendations might reduce the occurrence of post-PCI suboptimal stent configurations.

Multimodal Comparisons of Results Achieved by Different Side Branch Ballooning Techniques for Bifurcation Provisional Stenting.

BACKGROUND: Stepwise provisional stenting is the gold standard for percutaneous coronary intervention (PCI) on bifurcation lesions, but the optimal ballooning technique for eventual side branch treatment is not established. The objective of the present study was to compare the stent configuration obtained by 2 different side branch optimization techniques performed after main vessel (MV) stent implantation: proximal optimization technique+kissing balloon inflation+final proximal optimization technique (POT/KBI/POT [PKP]) versus proximal optimization technique+isolated side branch dilation+final proximal optimization technique (POT-side-POT [PSP]). METHODS: We realized a 1:1 prospective randomized trial comparing bifurcation PCI conducted (under angiographic and angioscopic visualization) with either PKP or PSP in reanimated swine hearts using commercially available drug-eluting stents. After PCI, the obtained stent configuration (expansion, eccentricity, apposition) was assessed by optical coherence tomography and micro-computed tomography dividing the stent in 4 segments. Primary study end point was minimum stent expansion at the distal MV segment. RESULTS: A total of 30 PCIs were successfully performed according to randomization obtaining overall good results (average minimum stent expansion >90% at optical coherence tomography and micro-computed tomography) with PSP or PKP. Minimum stent expansion at the distal MV segment was significantly higher with PKP as compared with PSP at optical coherence tomography (97.9±4.2% versus 91.0±7.7%; P=0.002) and micro-computed tomography (98.1±4.1% versus 91.3±7.9%; P=0.006). Other significant findings included higher stent eccentricity index at proximal MV with PSP, higher side branch scaffolding length and lower malapposition (at bifurcation core and distal MV) with PKP. CONCLUSIONS: This first prospective randomized trial in a unique non-atherosclerotic preclinical environment showed that bifurcation PCI conducted with PSP and PKP achieves different stent configurations. These findings might be useful in bifurcation PCI practice and call for further evaluations in clinical ground.

Clinical impact of the extent of jeopardized myocardium in patients undergoing transcatheter aortic valve intervention.

INTRODUCTION AND OBJECTIVES: Coronary artery disease (CAD) is found in 30%-50% of patients with severe aortic stenosis (AS) undergoing treatment. The best management of CAD in AS patients undergoing transcatheter aortic valve implantation (TAVI) is still unclear. We investigated the clinical impact of the extent of jeopardized myocardium in patients with concomitant CAD and severe AS treated by TAVI. METHODS: Consecutive patients who underwent TAVI procedures at our hospital were identified. In the presence of CAD, the myocardium jeopardized before TAVI was graded using the British Cardiovascular Intervention Society (BCIS) jeopardy score (JS). The study population was divided in 3 groups: patients without concomitant CAD (no-CAD), patients with CAD and BCIS-JS ≤ 4 (CAD BCIS-JS ≤ 4) and patients with concomitant CAD and BCIS-JS> 4 (CAD BCIS-JS> 4). The primary study endpoint was major adverse cardiovascular and cerebrovascular events (MACCE). RESULTS: A total of 403 patients entered the study: 223 no-CAD, 94 CAD BCIS-JS ≤ 4 and 86 CAD BCIS-JS> 4. At> 3 months of follow-up [range 104-3296 days], patients without CAD and CAD patients with BCIS-JS ≤ 4 had better survival free from MACCE compared with those with less extensive revascularization (BCIS-JS> 4) (P=.049). This result was driven by a significant reduction in death (P=.031). On multivariate analysis, residual BCIS-JS ≤ 4 and NYHA class III-IV independently predicted MACCE. CONCLUSIONS: In patients with concomitant CAD and severe AS, the extent of jeopardized myocardium before TAVI impacts on clinical outcomes.

Under-deployment of extra-large drug-eluting stent: an adapted provisional technique for selected patients with distal lesions in large left main.

BACKGROUND: In provisional technique, main vessel (MV) drug-eluting stent (DES) diameter is usually selected according to distal MV to reduce carina shift. Proximal optimization technique (POT) is used to expand the DES in the proximal MV. Occasionally, the size discrepancy between left main (LM) and left anterior descending artery (LAD) may be huge and this may cause stent malapposition and poor vessel wall coverage in large-sized LM. Recently, some manufactures designed extra-large DES to treat large vessels. METHODS: We developed an "adapted" provisional strategy based on under-deployment of extra-large DES in case of major size mismatch between LM and proximal LAD. Bench tests were realized in appropriately designed LM bifurcation model using an extra-large DES (Onyx XL, Medtronic, Santa Rosa, CA, USA). This technique was adopted when such "rare" anatomy was found in our clinical practice. RESULTS: At bench test, Onyx XL 4.5 mm stent reaches 3.8 mm at 5-6 atmospheres, with favorable stent deformation achieved after POT, kissing balloon and re-POT. This technique was performed in 10 patients undergoing unprotected LM stenting with large LM and major mismatch toward LAD. Angiographic success was achieved in all cases and optical coherence tomography assessment was performed in 5 patients revealing optimal stent result. After a follow-up of 557 days (range: 90-1369 days), clinical course was uneventful in all treated patients. CONCLUSIONS: Under-deployment of extra-large DES is a technical option that can be considered to optimize the provisional stenting technique in selected patients with major diameter mismatch between large-sized LM and LAD.

Transcatether Aortic Valve Implantation to Treat Degenerated Surgical Bioprosthesis: Focus on the Specific Procedural Challenges.

Actually transcatheter aortic valve implantation within failed surgically bioprosthetic valves (VIV-TAVI) is an established procedure in patients at high risk for repeat surgical aortic valve intervention. Although less invasive than surgical reintervention, VIV-TAVI procedure offers potential challenges, such as higher rates of prosthesis-patient mismatch and coronary obstruction. Thus, optimal procedural planning plays an important role to minimize the risk of procedure complications. In this review, we describe the key points of a VIV-TAVI procedure to optimize outcomes and reduce the risk of procedure complications.

Pledget-assisted hemostasis to fix residual access-site bleedings after double pre-closure technique.

BACKGROUND: The use of pre-closure suture-based devices represents a widely access-site hemostasis technique in percutaneous transfemoral transcatheter-aortic-valve-replacement (TF-TAVR); yet this technique is associated with the risk of a device failure that may result in clinically relevant residual bleeding. Thus, a bailout intervention is needed. So far, the best management of pre-closure device failure has not been recognized. AIM: To report the first clinical results obtained using a novel bailout hemostasis technique for patients with double suture-based vascular closure device failure in the setting of TF-TAVR. METHODS: We developed a "pledget-assisted hemostasis" technique to manage residual access-site bleeding. This consists of the insertion of a surgical, non-absorbable, polytetrafluoroethylene pledget over the sutures of the two ProGlide (Abbott Vascular, CA, United States). The ProGlide's knot-pushers are used to push down the pledget and the hand-made slipknot to seal the femoral artery leak. This technique was used as a bailout strategy in patients undergoing TF-TAVR with a systematic double pre-closure technique. Post-procedural access-site angiography was systematically performed. In-hospital complications were systematically detected and classified according to Valve Academic Research Consortium-2 criteria. RESULTS: Out of 136 consecutive patients who underwent TF-TAVR, 15 patients (mean age 80.0 ± 7.2 years, 66.7% female) with access-site bleeding after double pre-closure technique failure were treated by pledget-assisted hemostasis. In the majority of patients, 16F sheath was used (n = 12; 80%). In 2 cases (13%), a peripheral balloon was also inflated in the iliac artery to limit blood loss during pledget preparation. Angiography-confirmed hemostasis (primary efficacy endpoint) was achieved in all patients. After the procedure, 1 patient required blood transfusion (2 units), and no other bleeding or major ischemic complication was noticed. CONCLUSION: The "pledget assisted hemostasis" might be considered as a possible bailout technique to treat patients with residual access site bleeding. Further studies are needed to compare this approach with other bail-out techniques.

Acute haemodynamic impact of transcatheter aortic valve implantation in patients with severe aortic stenosis.

AIMS: There are limited data about the intraprocedural haemodynamic study performed immediately before and after transcatheter aortic valve implantation (TAVI) in patients with severe aortic stenosis (AS). We aimed to evaluate the acute haemodynamic impact of TAVI in patients with severe AS and to investigate invasive and non-invasive parameters predicting all-cause mortality. METHODS AND RESULTS: A total of 245 consecutive AS patients (43% male, mean age 80.3 ± 7.3 years) undergoing TAVI were enrolled. Intraprocedural left heart catheterization (LHC) and echocardiogram before and after TAVI were performed. The clinical endpoint was the death for any cause. LHC after TAVI revealed significant changes in aortic and left ventricular (LV) pressures, including indexes of intrinsic myocardial contractility and diastolic function such as positive dP/dT (1128.9 ± 398.7 vs. 806.3 ± 247.2 mmHg/s, P Ë‚ 0.001) and negative dP/dT (1310.7 ± 431.1 vs. 1075.1 ± 440.8 mmHg/s, P Ë‚ 0.001). Post-TAVI echo showed a significant reduction in LV end-diastolic (P = 0.036) and end-systolic (P Ë‚ 0.001) diameters, improvement in LV ejection fraction (from 55 ± 12% to 57.2 ± 10.5%, P Ë‚ 0.001), and pulmonary artery systolic pressure (42.1 ± 14.2 vs. 33.1 ± 10.7 mmHg, P < 0.001). After a mean follow-up time interval of 24 months, 47 patients died. Post-TAVI significant aortic regurgitation at echocardiography was the only independent predictor of mortality (hazard ratio 5.592, confidence interval 1.932-16.184, P = 0.002). CONCLUSIONS: Left heart catheterization performed immediately before and after prosthesis release offers a unique insight in the assessment of LV adaptation to severe AS and the impact of TAVI on LV, catching changes in indexes of intrinsic contractility and myocardial relaxation. Aortic regurgitation assessed by echocardiography was the only independent predictor of mortality in patients undergoing TAVI.

An "Orthotopic" Snorkel-Stenting Technique to Maintain Coronary Patency During Transcatheter Aortic Valve Replacement.

Coronary artery obstruction (CAO) during transcatheter-aortic-valve replacement (TAVR) represents a main concern for TAVR safety in patients with low coronary take-off. To date, "snorkel" (also called chimney) technique, consisting of stent implantation from the coronary ostium to the aorta within the space between the valve frame and the aortic wall, is the most adopted strategy to prevent CAO. This technique is associated with the creation of complex valve/stent configuration that can hinder repeat coronary interventions. Due to this concern, we set up an original sequence for coronary protection aiming to ensure a more physiological TAVR frame/stent configuration. According to this technique, TAVR prosthesis is released with a "protection" system consisting of guiding catheter (GC), wire and stent inside the coronary artery with high CAO risk. In the case of CAO occurrence, the stent is released according to the snorkel technique. In the absence of complete CAO, a new GC is advanced inside the implanted TAVR prosthesis and the stent is deployed from the coronary artery up to the prosthesis. We herein report two cases of very high CAO risk where this technique was successfully used during last-generation self-expandable prostheses implantation (in a native aortic valve and in one prosthetic aortic valve). In conclusion, this "orthotopic snorkel-stenting in TAVR" (OST) technique represents a novel option for treating impeding CAO during TAVR. As compared with the "classic" snorkel technique, it allows avoiding stent implantation in some patients (who do not experience CAO) and may provide a more predictable and physiologic TAVR prosthesis/stent configuration in the case of stent implantation need.