Transcatheter aortic valve implantation with a mechanically expandable prosthesis: a learning experience for permanent pacemaker implantation rate reduction.

BACKGROUND: Permanent pacemaker implantation (PPMI) after transcatheter aortic valve implantation (TAVI) remains an issue open for criticism. Aim of this study is to investigate a strategy to reduce PPMI rate after TAVI in general and more specifically after implantation of the LOTUS® prosthesis. METHODS: Through our learning curve, we have developed a structured protocol to reduce PPMI rate. The protocol includes: shallow implantation depth within the native annulus, strict adherence to the international guidelines for PPMI, PPMI not earlier than 5 days after TAVI, and intravenous chronotropic and steroidal treatment (orciprenaline 0.6-1.7 mg/h i.v. and dexamethasone 25 mg/day i.v. for a maximum of 5 days) in case of acute onset of intraventricular and/or atrio-ventricular conduction disturbances after TAVI. RESULTS: The first 35 patients (group A) were managed as per routine in our early stage experience with the LOTUS valve. The PPMI reduction protocol was applied in the second phase on the last 31 patients (group B). The PPMI rate was reduced from 34.3% (12/35) to 9.7% (3/31) (p = 0.02). At logistic regression analysis being treated in the second phase of our experience (group B) had a protective effect against PPMI (p = 0.05; OR = 0.1; CI = 0.01-1.0). Prosthesis implantation depth was directly related to PPMI (p = 0.005; OR = 2.0; CI = 1.2-3.2). Receiver operating characteristic curve analysis confirmed that a LOTUS implantation depth > 4.8 mm was the cut-off to predict PPMI (AUC = 0.8; p = 0.003; CI = 0.6-0.9) with maximal sensitivity (78.6%) and specificity (73.2%). CONCLUSIONS: PPMI rate after LOTUS can be reduced with experience by applying specific clinical and operative strategies.

Transcatheter aortic valve implantation with the direct flow medical prosthesis: Impact of native aortic valve calcification degree on outcomes.

OBJECTIVES: We present our single center experience with the direct flow medical (DFM) prosthesis addressing the impact of native aortic valve (AV) calcification degree on outcomes. BACKGROUND: The DFM® has been introduced for transcatheter aortic valve implantation (TAVI). The valve has a nonmetallic and inflatable support structure. METHODS: Patients were divided in two groups according to preoperative cardiac computed tomography (CT): group I moderate calcification and group II heavy calcification of the total AV area. We evaluated 118 patients: 53 (45%) group I and 65 (55%) group II. RESULTS: Preoperative trans-AV gradient and calcification extension across the aortic unit were significantly higher in group II (P = 0.008 and P < 0.0001). CT perimeter derived annular diameter (group I 24.7 ± 2.1 mm vs. group II 24.8 ± 1.9; P = 0.6) and implanted prosthesis size (group I 26.1 ± 1.5 mm vs. group II 25.7 ± 1.5; P = 0.1) were similar. Hemodynamics were similar: mean gradient 16.1 ± 5.9 mm Hg (group I) vs. 17.3 ± 6.5 mm Hg (group II) (P = 0.3). Total aortic regurgitation (AR) was mild in 5.7% in group I and 20% in group II (P = 0.03). None developed moderate/severe AR. Heavy AV calcification was the sole independent determinant for mild regurgitation (P = 0.02; OR = 7; 95% CI: 1.2-37.6). Follow-up (289 days; 40-760 days) estimated survival was 88.1% (group I) and 93.8% (group II) (P = 0.3). CONCLUSIONS: Independent of AV calcification degree, adequate sizing and implantation can be achieved with the DFM®. Although higher burden of calcification increases the rate of mild AR, no patient developed moderate and severe AR. Short-term estimated survival was not influenced by calcification degree. © 2016 Wiley Periodicals, Inc.

Trans-catheter aortic valve implantation with the direct flow medical prosthesis: Single center short-term clinical and echocardiographic outcomes.

OBJECTIVES: To analyze our single center experience with the Direct Flow Medical (DFM). BACKGROUND: The DFM has been recently introduced to the market and large real world experiences are lacking. METHODS: A total of 126 patients with severe aortic valve stenosis (AVS) were treated by the same team from March 2013 to May 2015. Device success and procedural safety were classified, according to valve academic research consortium (VARC) criteria, for the entire cohort, including patients treated in the early phases of our learning curve. RESULTS: Clinical and trans-thoracic echocardiography follow-up was performed (median duration 279 days; 36-761 days). Mean age was 80.9 ± 5.5 years and median logistic Euro-SCORE was 15.9 (5.5-84.2). Cardiovascular 30-day mortality was 4.8% (6/126), device success 89.6% (113/126), and early safety 85.7% (108/126). At discharge, no aortic regurgitation (AR) was present in 85.7% and mild AR in 14.3% of the patients. Estimated 1-year follow-up survival was 91%. At follow-up, no AR was present in 87.3%, mild AR in 10.9%, and moderate AR in 1.8%. Mean gradient of 15.1 ± 6.3 mm Hg and prosthesis effective orifice area of 1.6 ± 0.6 cm2 were reported. CONCLUSIONS: In this single center experience, the DFM valve showed satisfactory clinical and hemodynamic results. Short-term follow-up confirmed the consistent clinical results, with low rates of AR and acceptable trans-prosthetic gradients and prosthetic effective orifice area. © 2016 Wiley Periodicals, Inc.

Transcatheter aortic valve implantation in obese patients: Overcoming technical challenges and maintaining adequate hemodynamic performance using new generation prostheses.

BACKGROUND: Second-generation TAVI prostheses may enhance the procedure reducing operative time and complications rate, maintaining adequate valve hemodynamic performance. We present our results with 2 new generation trans-catheter aortic valve (TAVI) prostheses in obese patients. METHODS: A series of 172 patients underwent trans-femoral TAVI with new generation prostheses (Direct Flow Medical, DFM®, and LOTUS®). Two groups were identified according to body mass index (BMI): group NO (125) BMI<30kg/m(2) and group O (47) BMI≥30kg/m(2). RESULTS: Trans-femoral approach was possible in all patients without conversion to conventional surgery/cardiopulmonary bypass. Operative/fluoroscopy time and contrast use were comparable. Vascular and bleeding complications were also equally represented in the 2 groups. Thirty-day mortality was 7.2% in group NO and 6.4% in group O (p=0.9). At discharge, aortic regurgitation was absent/mild in 96% of group NO and in all patients in group O (p=0.3). Mild prosthetic stenosis was reported in 3.8% of the patients in group NO and 2.2% in group O. No moderate/severe prosthetic stenosis was reported. Estimated 1-year survival was 93.1% in group NO and 83.2% in group O (p=0.6). Estimated 1-year freedom from MACCE was 74.7% in group NO and 62.8% in group O (p=0.4). At follow-up echocardiography no significant differences were noticed in the 2 groups. CONCLUSIONS: Second generation TAVI prostheses allow for safe and effective procedures in obese patients. In spite of patient's body habitus, agile prosthesis placement will lead to optimized hemodynamics. Valve and clinical performance are confirmed at follow-up.

Transcatheter, inflatable, and fully repositionable aortic valve: Preliminary results using a modified implantation technique.

OBJECTIVES: We present our experience with an inflatable, non-metallic, fully retrievable, and repositionable transcatheter aortic valve [Direct Flow® Medical (DFM)] focusing on technical features adopted during implantation. BACKGROUND: Implantation techniques of new generation percutaneous aortic valves are still developing and with experience implementations are described. METHODS: The "low pressure" (initial valve inflation at 4 ATM, lower than the recommended 12 ATM) and the "alternate aortic curve" techniques (initial valve pulling either from the wire running on the side of the inner or from the one on the outer aortic curve) are part of our modified protocol for DFM® implantation. RESULTS: Forty-two consecutive patients underwent TAVI with DFM. The "low pressure" technique was used in all patients. In 27 (64.3%) patients the bulkiest calcifications were on the inner aortic curve side, and an inner curve technique was used to initiate valve pulling toward the annular hinge point. In the remaining 15 (35.7%) patients, an outer curve technique was used. Neither pull-through nor re-valving was reported. Valve performance showed mean gradient of 8.9 mm Hg. Mild paravalvular leak was reported in seven (16%) patients. No one experienced moderate or severe aortic insufficiency. Thirty-day mortality was 9.5% (4/42). CONCLUSION: The "low pressure technique" and the "alternate curve technique" guarantee an anatomy and patient tailored approach to achieve controlled and finely tuned valve seating.

Treatment of secondary mitral valve regurgitation: why we need combined and evolving percutaneous strategies to tackle this moving target.

Secondary mitral regurgitation (MR) has a complex pathophysiology that includes global or segmental left ventricular (LV) motion abnormalities (of non-ischaemic or ischaemic origin) leading to impaired leaflet coaptation of a normally structured mitral valve (MV). In this context, the LV functional and geometrical changes result in MV leaflet tethering, MV annulus flattening and the decrement of systolic MV closing forces. In light of its complexity, management of secondary MR remains a challenge. In fact, a long-lasting successful treatment using a single medical device and/or intervention that addresses solely the MV target cannot, at least at the present time, be proposed.