Sutureless Perceval Aortic Valve Replacement: Results of Two European Centers

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1 Sutureless Perceval Aortic Valve Replacement: Results of Two European Centers Thierry A Folliguet, MD, François Laborde, MD, Konstantinos Zannis, MD, Gabriel Ghorayeb, MD, Axel Haverich, MD, and Malakh Shrestha, MD Institut Mutualiste Montsouris, Paris, France; Medizinsche Hochschule Hannover, Hannover, Germany Background. The Perceval S bioprosthesis (Sorin Biomedica Cardio Srl, Sallugia, Italy) is a self-expanding valve designed to preserve aortic sinuses and sinotubular junction. We report the midterm results of a prospective, multicenter clinical study evaluating the safety and efficacy of this stented bioprosthesis in patients undergoing aortic valve replacement with or without concomitant procedures. Methods. From January 2007 to September 2011, a total of 208 high-risk patients (mean European system for cardiac operative risk evaluation: years) received a Perceval bioprosthesis in 2 European centers. Median follow up was months and 100% complete, and the total accumulated follow-up was 156 patient-years. Ten patients have reached a 4-year follow-up. Valve function was assessed in all patients. Results. Valve implantation resulted in significant improvement of patients symptoms. Mean preoperative and postoperative gradients were mm Hg and mm Hg, respectively, and preoperative and postoperative mean effective orifice areas were and cm 2. Survival at 12 months was 87.1%, success of implantation was 95%, and freedom from reoperation was 96%. In hospital mortality was 2.4%. During follow-up, 9 patients (4%) required reoperation for paravalvular regurgitation; 7 early and 2 late reoperations. Mean cross-clamp time (CCT) and extracorporeal circulation time (ECT) were, respectively, minutes and minutes, including 45 patients who underwent surgery through ministernotomy. Concomitant coronary bypass was done in 48 patients with mean CCT and ECT minutes. Conclusions. Perceval sutureless is a safe bioprosthesis that can easily be implanted, including by a minimally invasive technique. It provides excellent hemodynamic with significant clinical improvement. Overall, these data confirm the safety and utility of the Perceval bioprosthesis aortic valve replacement for high-risk patients. (Ann Thorac Surg 2012;93:1483 8) 2012 by The Society of Thoracic Surgeons Aortic valve replacement with biologic heart valves is the treatment of choice for aortic valve stenosis when it is symptomatic or with severe aortic stenosis ( 0.6 cm 2 /m 2 ), with left ventricular dysfunction, or for older patients [1]. Many clinical reports have shown excellent reports with pericardial and porcine valves with very low gradient and improved long-term durability, with results up to 20 years [2 12]. However, all these valves are mounted on a stent with a Dacron (DuPont, Wilmington, DE) cuff that allows the prosthesis to be sutured to the aortic annulus. In a small and calcified annulus it can be challenging to insert and a significant residual gradient is frequently observed afterward. Stentless valves have been designed in order to overcome some of the disadvantages of the stented valve [13, 14]. By removing the stent, these bioprostheses provide a greater orifice area and preserve the distensibility of the annulus as well as the sinotubular junction expansibility. Over their stented counterpart they offer a greater effective orifice area and lower hemodynamic Accepted for publication Jan 20, Address correspondence to Dr Folliguet, Department of Cardiac Surgery, L Institut Mutualiste Montsouris, 42 boulevard Jourdan, Paris, France; thierry.folliguet@imm.fr. gradients [15]. However, they are more difficult to insert, with increased cross-clamp time, and their immediate results do not translate in improved longterm results [16, 17]. In addition, some of these valves exhibit late structural valve failure compared with stented valves, with wearing and tearing at the commissures [18 20], therefore, the sutureless Perceval bioprosthesis (Sorin Biomedica Cardio Srl, Sallugia, Italy) was designed in order to obtain the hemodynamic benefits of the stentless valves without the increased difficulty in surgical implantation. The design of the Perceval S prosthesis stems from the intention to offer an alternative to traditional flexible prostheses (stented and stentless biologic valves) using conventional open-heart surgery. As a result of the sutureless implant procedure, patients could benefit from reducing aortic cross-clamp times, with subsequent overall reduction of surgical timing and therefore reduction in related risks by avoiding to pass the stitches through the annulus and sutures knotting, with consequent less risk of tearing the aortic annulus and wall, damaging the bundle of His, or embolizing foreign material in the vascular system [21]. We report our experience with the Perceval S bioprosthesis implanted at 2 different institutions by The Society of Thoracic Surgeons /$36.00 Published by Elsevier Inc doi: /j.athoracsur

2 1484 FOLLIGUET ET AL Ann Thorac Surg SUTURELESS PERCEVAL AVR: RESULTS 2012;93: Material and Methods Patient Population From January 2007 to September 2011, a total of 211 patients (83 males, 128 females; mean age years) were enrolled into this prospective, international, multicenter nonrandomized study. Participants were implanted with the Perceval sutureless bioprosthesis at 2 participating European investigational sites; Institut Mutualiste Montsouris (Paris, France) and Medizinsche Hochschule Hannover (Hannover, Germany). Inclusion and exclusion criteria are listed in Table 1. High-risk patients defined as a logistic EuroSCORE (European system for cardiac operative risk evaluation) greater than 5% requiring isolated aortic valve replacement, with or without concomitant procedures, were eligible to participate. The mean EuroSCORE was The Institutional Review Boards and the local Ethics Committee of each hospital gave approval for this study. All patients gave informed written consent and were informed adequately regarding the investigational status of the device, the associated benefits and risks, and the availability of alternative treatment options. Device Description The Perceval S prosthesis is made of a trileaflet bovine pericardial valve mounted on an expandable metal frame in nitinol (equiatomic alloy of nickel and titanium). The Perceval S prosthesis has the special feature that it does not have to be surgically sutured into the implant site as this function is performed by the armature which, as well as supporting the valve edges, adapts itself to the aortic root to which it is anchored. The armature has 2 cylindrical ring segments, on the proximal ( outflow ring) and distal ( inflow ring) sides, and a double set of posts that couple the 2 rings. The first set comprises straight posts designed to support the valve while the second set is sinusoidal, protruding from the cylindrical geometry to allow the prosthesis to be anchored to the aortic root in the Valsalva sinuses. The armature s superelastic alloy and its architectural design allow the device to be compressed to a diameter less than the working geometry in the phase before positioning at the site. The later release from constraint allows the superelastic materials to self-expand so as to reach a final diameter compatible with the aortic root. Thus, once in place and deployed the device is fixed to the annulus and the aorta, and does not expand or move. The biologic tissue was stabilized with glutaraldehyde, using the manufacturing process already tested with traditional biologic valves produced by Sorin Biomedica Cardio s.r.l. Currently, 3 sizes are available at 21, 23, and 25 mm for annuli ranging from 19 to 24 mm. Surgical Technique; Exposure and Incision in the Aorta The aortic incision is performed at the distal portion at the sinotubular junction to preserve a segment of ascending aorta above the prosthetic valve. The aortic valve should be excised at a position corresponding to the incision line of the native leaflets and the aortic annulus should be decalcified to prepare the implant site. Given the characteristics of the prosthesis, a complete decalcification of the aortic annulus is not necessary, but a regular annular profile is beneficial to aid coupling with the prosthesis and to minimize the risk of paraprosthetic leak. If necessary, a partial septal myectomy is recommended. The measurement of the aortic annulus diameter, after the decalcification procedure, must be carried out using dedicated sizers. Positioning and Release of the Prosthesis To ensure the correct positioning and orientation of the prosthesis, 3 suture threads were used to act as reference for accurate alignment of the inflow portion of the prosthesis with the insertion plane of the native leaflets. For each valve sinus, 1 stitch was positioned immediately 2 to 3 mm below the lowest portion of the native leaflet resection line (Fig 1). On the prosthesis, each thread was passed into a dedicated thread loop located at the midlevel of the inflow ring and aligned to the median part of the prosthetic sinuses. Once the prosthesis is connected to the 3 guidethreads, the release device was introduced into the aorta Table 1. Indications and Contraindications for the Sutureless Perceval S Indications Inclusion Criteria Subjects of age 65 years; Subjects with aortic valve stenosis or steno-insufficiency; Subjects in NYHA functional classes III and IV with the logistic EuroSCORE greater than 5%; Subjects who have agreed to participation in the clinical evaluation and who have signed the informed consent. EuroSCORE European system for cardiac operative risk evaluation; Contraindications Exclusion Criteria Subjects with aneurysmal dilation or dissection of the ascending aortic wall needing surgical correction; Subjects needing nonelective intervention; Subjects with aortic annulus (after procedure for decalcification) of dimensions such that the implantation of a valve of size 21 or 23 mm is not possible (direct intraoperative measurement with sizer); Subjects with congenital bicuspid aortic valve; Subjects with aortic root enlargement, where the ratio between observed and expected diameters (calculated as a function of age and patient body surface area) is 1.3; Subjects with known hypersensitivity to nickel alloys. NYHA New York Heart Association.

3 Ann Thorac Surg FOLLIGUET ET AL 2012;93: SUTURELESS PERCEVAL AVR: RESULTS 1485 Fig 1. Valve design features: button holes. Button holes allow correct axial-rotational positioning in the native aortic root. (LC left coronary; NC noncoronary; RC right coronary.) and parachuted down to the point at which it was blocked by the previously positioned stitches. This positioning was followed by freeing of the inflow portion of the prosthesis, allowing the inflow ring to come in contact with the annulus (Fig 2). After checking that the Perceval S prosthesis was well seated within the aortic root, the guide-threads were removed during balloon inflation. A balloon dilation of the inflow ring was performed after the total deployment of the prosthesis. As the balloon is completely deflated, the catheter can be removed from the operative field. Statistical Methods SAFETY ENDPOINTS. Safety of the Perceval S prosthesis was evaluated based on all cardiovascular complications related to cardiac valve replacement, as defined in reference 22. Each serious adverse event (death, structural deterioration, thrombosis, embolism, hemorrhage, endocarditis, clinically significant hemolysis, and nonstructural dysfunction (including paraprosthetic and intraprosthetic leak) were recorded during hospitalization and follow-up. This analysis was also performed for valve reinterventions, including those that entailed replacement of a valve prosthesis and those that did not result in explants of the prosthesis being assessed. Morbid events were stratified as early ( 30 days) or late ( 30 days) postoperative events. The analysis of death included all deaths and analysis of valve-related deaths. Rates of early postoperative events were calculated as a percentage of patients who experience each event, calculated as the number of events divided by the number of patients. For the late postoperative period, linearized rates were calculated as the number of events per 100 patient-years of patient exposure. Actuarial analysis that includes all events was used to show the probability of freedom from first occurrence of each complication at the end of different intervals. The Kaplan-Meier method was used to produce actuarial curves and comparison of curves among patient groups (eg, sex, New York Heart Association [NYHA] class) was performed with the log-rank test at a 0.05 level of significance. Cox proportional hazard regression was applied to identify any risk factors collected in this study that may affect the incidence of reoperation, explants, or death. Performance Endpoints Immediate postoperative aortic regurgitation was evaluated after valve deployment and termination of extracorporeal circulation. The echocardiographic measurements included: peak and mean transvalvular pressure gradients were derived by using the modified Bernoulli s Fig 2. Valve design features dual collar design, with supraannular and intraannular sealing collar.

4 1486 FOLLIGUET ET AL Ann Thorac Surg SUTURELESS PERCEVAL AVR: RESULTS 2012;93: Table 2. Preoperative Patient Demographics Patient Characteristics (%) n 208 Age [years] Sex Male 67 Female 141 NYHA status III 187 pts (93) IV 21 pts (27) Previous cardiac surgery 6 Previous pace maker 15 EuroSCORE [logistic] Ejection fraction ( ) Diabetes % 58 (28) Hypertension % 142 (68) Chronic obstructive lung 32 (15) disease Body mass index EuroSCORE European system for cardiac operative risk evaluation; NYHA New York Heart Association; pts patients. equation, and the effective orifice area was calculated with the continuity equation. According to the echocardiographic protocol, the hemodynamic effectiveness endpoints recorded were mean and peak P, effective orifice area and indexed effective orifice area, cardiac output, cardiac index, ejection fraction, location, and severity degree of aortic and mitral regurgitations. Hemodynamic data were presented as number of patients, means, standard deviations, and ranges for each continuous parameter. Valve regurgitation was presented as numbers and percentages of patients with each grade of regurgitation. Postoperative echo data were analyzed for time-related variation of the degree of aortic regurgitation. The NYHA functional classification data were presented as the number and percentage of patients in each functional class. Patient improvement after implant of the Perceval S prosthesis was determined by comparison of preoperative and postoperative NYHA functional classifications, through application of the Wilcoxon range test. All statistical analysis was performed using the SAS System for Windows (version 9) (SAS Inc, Cary, NC). Results Patient and Procedure Characteristics Patient demographics and operative details are summarized in Tables 2 and 3. The indication for the surgery included degenerative native aortic valve disease in all patients. The total accumulated follow-up was 156 patient-years, as of the cutoff date for the present report. Three patients enrolled were excluded from the study after signed consent due to a larger annulus ( 25 mm) measured on the echocardiogram, and therefore a total of 208 patients received a Perceval sutureless bioprosthesis. There were no intraprocedural deaths. Forty-four patients received concomitant coronary revascularization. Five patients (2.4%) died during hospital stay. Autopsy, however, revealed no valve-related pathologies; the valve was seated appropriately inside the aortic annulus with patent coronary ostia. Twenty patients died during follow-up. Cumulative freedom from valve-related mortality (96% confidence interval) was 87.1% at 1 year, 82.4% at 2 years, 82% at 3 years, and 69.7% at 4 years (Fig 3). Mean follow-up was days, with a cumulative 156 patient-year. Implantation was successful in 95.6% of patients. In 9 patients immediate paravalvular leak (PVL) was noted during implantation; it was treated in 7 patients with a Perceval bioprosthesis and in 2 patients with a stented bioprosthesis. All these patients had a normal recovery. Perioperative morbidity was recorded for each patient during hospitalization and during follow-up. During follow-up 9 patients (4%) developed PVL, which required reoperations: early in 7 patients (from postoperative day 2 to postoperative day 13) and later in 2 patients; at 163 days and 576 days both developed intraprosthetic leak, 1 due to endocarditis and the other due to a pannus ingrowth on the stent, restricting a leaflet. In the serial echocardiograms performed regularly no other cases of restriction or dysfunction of the leaflets have been detected. Minor PVL not requiring surgical intervention was noted in 5 patients. No increase in the size of aortic insufficiency has been noted during follow-up. Bleeding events occurred in 13 patients (9 early, 4 late) requiring transfusions. Ten episodes of thromboembolism occurred during follow-up; 2 strokes, 1 transient ischemic attack, 3 limb embolism, 2 pulmonary embo- Table 3. Perceval S, Intraoperative Characteristics Intra/Postoperative Data Patients (n 208) Median Sternotomy (n 163) Mini Sternotomy (n 45) With Concomitant CABG (n 48) Isolated AVR Patients (n 160) Cross-clamp time [min] CPB-time [min] Valve size [mm] AVR aortic valve replacement; CABG coronary artery bypass grafting; CPB cardiopulmonary bypass; min minutes.

5 Ann Thorac Surg FOLLIGUET ET AL 2012;93: SUTURELESS PERCEVAL AVR: RESULTS 1487 symptoms at the 1-year and 2-year follow-up visits. These data represent a significant (p 0.001) improvement in the functional capacity of most patients undergoing aortic valve replacement with the Perceval S aortic bioprosthesis. Fig 3. Overall survival for Perceval S patients. lisms, and 1 retinal embolism. Pericardial effusion occurred in 4 patients requiring drainage, sepsis other than endocarditis requiring antibiotics occurred in 18 patients, and heart failure requiring inotropic drugs occurred in 5 patients. Endocarditis was diagnosed in 3 patients leading to 2 reoperations, while the third patient was managed medically and responded well to medical treatment. There was 1 case of hemolysis due to PVL. Pacemaker insertion for atrioventricular block was necessary in 16 patients (7%). Hemodynamic Parameters Transthoracic echocardiography was performed and hemodynamic parameters were obtained at the time of hospital discharge and at regularly scheduled outpatient visits at 3 to 6 months and 12 to 13 months. The average mean aortic gradient was measured at mm Hg. The mean effective orifice area was cm 2 and a mean indexed effective orifice area was cm 2 /m 2 (Table 4). No migration or dislodgement of the prosthesis has occurred during further follow-up. Effect of Aortic Valve Replacement on the NYHA Functional Capacity The NYHA functional capacity was evaluated and recorded preoperatively and at all subsequent visits. As shown in Table 2, all patients were categorized as NYHA class III or IV at the preimplantation assessment. By contrast, 82% of patients reported NYHA class I and II Comment Recent published series of conventional aortic valve replacement performed in octogenarians show an operative mortality between 4% and 10% [23 25]. Age itself is not a contraindication to conventional surgery but comorbidities such as low ejection fraction, renal failure, and calcified aorta are major risk factors [24]. In our study, the sutureless Perceval S aortic valve can be implanted after thorough surgical removal of the diseased valve, as done with conventional valve replacement. Mortality remains low, with minimal morbidity despite the increased risk of the population. Our early experience at 2 different institutions in Europe suggests an extremely secure valve positioning with very low gradient, including in a small annulus, and with excellent hemodynamics. This is in comparison with other reported sutureless valves which all have improved hemodynamics and low gradients [26]. Compared with stented bioprostheses this sutureless valve can be implanted with reduced cross-clamp time and extracorporeal time. This can be an advantage in patients requiring an added procedure; such as concomitant coronary artery bypass in older patients. In this case the sizing should be done first and the loading of the valve can be done while bypass is being performed. Once inserted there were no migrations of the valve and minimal complications were encountered during follow-up. Early nonfatal complications were documented in 4%, which is reflected by PVL. This can be a result of either inadequate sizing or due to inappropriate decalcification of the annulus. Due to its design this device has a round circumference that holds by its expandable structure nitinol; therefore, a circular rim of calcium should be left at the annulus level to assure proper anchoring without PVL. An important finding in our study is that when PVL is found intraoperatively or immediately postoperative, it should be immediately corrected. Either a new sutureless of usually different size can be placed, or a sutured bioprosthesis implanted. Older patients with a hypertrophic ventricle do not tolerate significant PVL, as rapidly they develop increased left ventricle diastolic pressure, Table 4. Hemodynamic Parameters During the Study Period, as Measured by Transthoracic Echocardiography Postoperative Variables Preoperative Discharge Post Implantation 3 6 months Post Implantation 1 4 years Mean gradient (mm Hg) Peak gradient (mm Hg) Effective orifice area (cm 2 ) Indexed effective orifice area (cm 2 /m 2 )

6 1488 FOLLIGUET ET AL Ann Thorac Surg SUTURELESS PERCEVAL AVR: RESULTS 2012;93: resulting in heart failure. Almost all patients with PVL were reoperated immediately or within a few days after the operation. Only 2 patients required late reoperation at 163 days and 576 days postoperative; 1 due to endocarditis and the other due to a fibrous pannus overgrowth. Another advantage of this bioprosthesis is its ease of insertion in minimal access surgery, as witnessed by a mean cross-clamp time of 33 minutes, which is identical to the sternotomy group. In small annuli (n 32, 23 mm), the gradients remained low as the mean gradient was mm Hg in this subgroup, which remains low compared with stented bioprostheses. In addition, no structural prosthetic deterioration, valve thrombosis, or significant transvalvular aortic regurgitation occurred during the study period. Cumulative freedom from valve-related mortality was 87% and 82% at 1 and 3 years, respectively. There were no cases of tilting or migration once appropriately inserted during the entire follow-up. Also, due to the unique design of the bioprosthesis, ostial blockage of the coronary arteries was never encountered. Further experience is needed to find the potential of the device for either an open or a minimally invasive approach. Furthermore, the sutureless bioprosthesis appears to be ideal for patients with severe calcification of the aortic root and patients requiring concomitant procedures in whom a reduced bypass time is mandatory. At this point, however, careful patient selection and echographic assessment are crucial in choosing the proper size. Correct sizing of the valve is critical to minimize paravalvular leakage and this should be performed with transesophageal echocardiography and intraoperative sizing. For an enlarged aorta with a ratio greater than 1.3, the predicted diameter according to body surface area represents a contraindication for this device. 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