Hemodynamic Comparison between the Avalus and the Perimount Magna Ease Aortic Bioprosthesis up to 5 Years.

BACKGROUND: We aimed to compare hemodynamic performance of the Avalus (Medtronic) and the Perimount Magna Ease (PME, Edwards Lifesciences) bioprosthesis up to 5 years by serial echocardiographic examinations. METHODS: In patients undergoing aortic valve replacement, 58 received PME prostheses between October 2007 and October 2008, and another 60 received Avalus prostheses between October 2014 and November 2015. To ensure similar baseline characteristics, we performed a propensity score matching based on left ventricular ejection fraction, age, body surface area, and aortic annulus diameter measured by intraoperative transesophageal echocardiography. Thereafter, 48 patients remained in each group. Mean age at operation was 67 ± 6 years and mean EuroSCORE-II was 1.7 ± 1.1. Both values did not differ significantly between the two groups. RESULTS: At 1 year the mean pressure gradient (MPG) was 15.4 ± 4.3 mm Hg in the PME group and 14.7 ± 5.1 mm Hg in the Avalus group (p = 0.32). The effective orifice area (EOA) was 1.65 ± 0.45 cm2 in the PME group and 1.62 ± 0.45 cm2 in the Avalus group (p = 0.79). At 5 years the MPG was 16.6 ± 5.1 mm Hg in the PME group and 14.7 ± 7.1 mm Hg in the Avalus group (p = 0.20). The EOA was 1.60 ± 0.49 cm2 in the PME group and 1.51 ± 0.40 cm2 in the Avalus group (p = 0.38). Five-year survival was 88% in the PME group and 91% in the Avalus group (p = 0.5). In the PME group, there were no reoperations on the aortic valve, whereas in the Avalus group three patients required a reoperation due to endocarditis. CONCLUSION: Both bioprostheses exhibit similar hemodynamic performance during a 5-year follow-up.

Serial echocardiographic evaluation of the Perimount Magna Ease prosthesis.

BACKGROUND: The Carpentier-Edwards Perimount Magna Ease prosthesis (PME) represents the latest generation of stented bioprostheses used for surgical aortic valve replacement (SAVR). The aim of our study was to evaluate the long-term clinical outcome and hemodynamic performance of the prosthesis with a focus on the incidence and course of structural valve deterioration (SVD) by serial echocardiographic examinations. METHODS: SAVR with the PME was performed in 58 consecutive patients between 2007 and 2008. Transthoracic echocardiography was performed preoperatively, at discharge and annually during a 10-year follow-up at the German Heart Center Munich. RESULTS: Mean age at surgery was 62±14 years. At discharge (n=57), the overall mean pressure gradient (MPG) and effective orifice area (EOA) were 15.8±4.1 mmHg and 1.8±0.4 cm2, respectively. Moderate patient-prosthesis mismatch (PPM) was present in 18 patients (32%) and severe PPM in 6 patients (11%) at discharge. Ten years following SAVR (n=33), the overall MPG was 16.6±7.3 mmHg and EOA was 1.3±0.4 cm2.Thirty-day and late mortality was 2% (n=1) and 21% (n=12), respectively. Survival at 1, 5, and 10 years was 94.7%±3.3%, 91.1%±4.1%, and 77.3%±5.9%, respectively. Freedom from reoperation at 10 years was 88.8%±4.7%. Ten years after PME implantation the cumulative incidence of any SVD, severe SVD, and bioprosthetic valve failure (BVF) was 25%±6%, 14%±5%, and 16%±5%, respectively. CONCLUSIONS: The PME shows an excellent hemodynamic performance over the course of 10 years with development of clinically relevant SVD as late as 6 years post implant, and a 10-year incidence of severe SVD of 14%.

Clinical performance of a three-dimensional saddle-shaped, rigid ring for mitral valve repair.

OBJECTIVES: The Profile 3D annuloplasty ring is a complete, rigid, saddle-shaped ring indicated for reconstruction and/or remodelling of the pathological mitral valve (MV) in patients with mitral insufficiency. METHODS: This prospective, non-randomized, observational, postmarket release study characterized the patient population for which the study ring was chosen for MV repair, assessed the relief from MV dysfunction and determined the level of mitral regurgitation (MR) at follow-up (6-12 months postimplant). RESULTS: Between February 2013 and July 2015, 151 patients were enrolled at 7 centres; data were excluded for 3 patients. The mean age of the remaining 148 patients was 63.8 ± 12.3 years, and 85 patients (57.4%) were men. Ischaemic cardiomyopathy was present in 15 patients (10.1%) and dilated cardiomyopathy in 12 patients (8.1%). MR was severe in 86 of 145 patients with available data (59.3%). Implantation was successful in 141 of 147 attempted procedures. Two deaths (n = 148, 1.4%) occurred within 30 days, and 1 death (0.7%) occurred >30 days after implant. Analysis of patients with data from both visits (n = 111) demonstrated that MR was none or mild in 94.5% of patients, moderate in 3.6% and moderate to severe in 1.8% at follow-up. Nearly all (104 of 109, 95.4%) patients were in New York Heart Association Class I/II. Among patients with ischaemic cardiomyopathy or dilated cardiomyopathy preoperatively, 16 of 19 patients with available data (84.2%) had no or mild MR at follow-up. CONCLUSIONS: MV repair using the Profile 3D annuloplasty ring is a safe and effective treatment for MR. Further investigation is warranted to determine whether patients with ischaemic cardiomyopathy or dilated cardiomyopathy derive unique benefit from this saddle-shaped ring. Clinical trial registration number: www.clinicaltrials.gov, NCT01112566.

Outcomes of patients undergoing third-time aortic or mitral valve replacement.

BACKGROUND AND AIM: Third-time valve surgery is rare and to date little is known about the surgical outcome. We reviewed our experience with third-time aortic valve replacement (AVR) and third-time mitral valve replacement (MVR) during an eight-year period. METHODS: From 2001 to 2013, 32 patients were referred for third-time AVR or third-time MVR to our institution. In this retrospective analysis, patients were evaluated for postoperative morbidity including: hemodialysis, cerebrovascular event, pacemaker implantation, and 30-day and mid-term mortality. RESULTS: Third-time replacement was for failed aortic valves in 20 (62.5%) patients and for failed mitral valves in 12 (37.5%) patients. Patients' mean age at the time of surgery was 56.3 ± 19 years. The mean interval between the first and the second procedure was 10 ± 7.8 years and between second and third replacement 7.3 ± 5.6 years. The failed prostheses included nine (28%) bioprostheses and 23 (72%) mechanical prostheses. The reasons for replacement were: infective valve endocarditis (31.3%), prosthesis dysfunction (37.3%), and paravalvular leakage (26%). The 30-day mortality was 18.8% and during follow-up was 31.3%. Hemodialysis was needed for eight patients (25.8%), pacemaker implantation for eight patients (25.8%), and cerebrovascular event occurred in four patients (13.3%). In patients with prosthetic valve endocarditis (n = 10), 30-day and overall mortality were 11.1% and 30%, respectively. CONCLUSION: Third-time aortic or mitral valve replacement is a rare procedure but accompanied with high morbidity and mortality, especially in patients with prosthetic valve endocarditis.

Autonomization of epigastric flaps in rats.

The question of how long a flap depends on its pedicle cannot be answered clearly from the available literature. To address this, we investigated the time to flap autonomization in the wound bed and the length of time to the point when flap necrosis is reduced to a clinically negligible level. The superficial epigastric flap was raised in 24 rats. After 3, 5, 7, or 10 days of wound healing, the pedicle was again exposed, ligated, and divided. Values of blood flow (flow), velocity (velocity), hemoglobin level (Hb), and oxygen saturation (SO(2) ) were noninvasively measured using Laser spectrophotometry. The area of necrosis of the flap was 62.77 ± 1.71% after 3 days, 16.26 ± 0.86% after 5 days, 2.88 ± 0.14% after 7 days, and 1.64 ± 0.16% after 10 days (P < 0.001). Hb, flow, and velocity were found to be significant factors on developing flap necrosis at the preoperative and postoperative time point (P < 0.0001), whereas SO(2) and flow were significant predictors of necrosis at the time of pedicle ligation (P < 0.0001). The percentage changes of SO(2) (P < 0.0001), flow (P < 0.0001), and velocity (P = 0.001) between the different time points were significant predictors of flap necrosis. The time needed for the complete autonomization of vascularized free flaps in their wound beds has been found as completed between the 5th and 7th day postoperatively in this rat model. The area of flap necrosis depends on the present value of SO(2) , Hb, flow, and velocity at different time points, but, more importantly, also on the perioperative change of these parameters.

Intermittent regurgitation caused by incomplete leaflet closure of the Medtronic ADVANTAGE bileaflet heart valve: analysis of the underlying mechanism.

OBJECTIVE: Clinical echocardiographic assessments of the Medtronic ADVANTAGE (Medtronic Inc, Minneapolis, Minn) prosthesis in the aortic position revealed a phenomenon identified as "intermittent regurgitation." An in vitro investigation was initiated to identify the underlying mechanism. METHODS: In a pulse duplicator environment, 6 ADVANTAGE size 23 aortic valves were analyzed. Leaflet motion and flow through the valves were documented using echocardiography with color Doppler flow, digital high speed imaging, and flow meter assessment. RESULTS: Intermittent regurgitation could be reproduced in all 6 of the tested valves within limited ranges of flow, pressure, and valve orientation. By virtue of high-speed imaging, the mechanism underlying intermittent regurgitation was identified. During intermittent regurgitation, the leading edge of the second-to-close leaflet makes contact with the chamfer on the leading edge of the first-to-close leaflet. The fluid closing forces working on the first-to-close leaflet prevent it from shifting back so that the leading edge of the second-to-close leaflet remains positioned against the chamfer of the first-to-close leaflet. In this position, the major radius of the second-to-close leaflet does not reach the housing's major radius. Therefore, a crescent-shaped gap remains between the leaflet tip of the second-to-close leaflet and the housing major radius during all or part of diastole. The regurgitant fraction can increase from a normal range of 6% to 25% during an intermittent regurgitation beat. CONCLUSIONS: In vitro intermittent regurgitation can be induced in the size 23 aortic ADVANTAGE valve under a limited range of conditions. To avoid possible misinterpretations, the phenomenon must be known in detail by all physicians dealing with patients with an ADVANTAGE valve.

A rat model of cardiopulmonary bypass with cardioplegic arrest and hemodynamic assessment by conductance catheter technique.

BACKGROUND: Cardiopulmonary bypass (CPB) is known to induce systemic inflammation and cardiac dysfunction associated with a significant morbidity. Aim of the study was to develop an in vivo model of rat CPB with hypothermic cardiac arrest and the use of cardioplegia. MATERIAL AND METHODS: The CPB circuit consisted of a venous reservoir, membrane oxygenator, heat exchanger, and roller pump. CPB was instituted in adult male Wistar rats (400-500 g) for 60 min at a flow rate of 120 ml x kg(-1) x min(-1), including 15 min cooling to 32 degrees C, 30 min cardiac arrest with the use of cold crystalloid cardioplegia after aortic cross clamping, and 15 min of reperfusion and rewarming to 37 degrees C. Arterial blood pressure (MAP) and heart rate (HR) were monitored, arterial blood samples were analyzed. Left ventricular (LV) function parameters were assessed by intraventricular conductance catheter. Important technical aspects are: ventilation is required during partial bypass; anticoagulation should be performed immediately prior to CPB to reduce blood loss; active suction on venous drainage allows higher pump flows; and the small priming volume of the extracorporeal circuit (8 ml) avoids the need for donor blood. RESULTS: MAP remained stable prior to and during CPB.MAP and HR were significantly decreased 60 min after weaning from bypass. Hct was significantly lowered after hemodilution, but remained stable during CPB and 60 min after weaning from bypass. BE and pH remained stable throughout the experiment.Without inotropic support diastolic and systolic LV function parameters were impaired after 30 min of cardioplegic arrest followed by 15 min of reperfusion. Myocardial TNF-alpha mRNA levels were slightly increased (1.28-fold, p = 0.71), and IL-6 mRNA was significantly increased in the cardioplegia group (90.3-fold, p = 0.001). Both IL-6 and TNF-alpha plasma levels were significantly elevated in the cardioplegia group (TNF-alpha: 4.6-fold increase,p < 0.05; IL-6: 426.8-fold increase, p < 0.001). CONCLUSIONS: We have developed a rat CPB with mild hypothermic cardioplegic arrest. This rodent model is suitable to study clinically relevant problems related to CPB,myocardial protection and systemic inflammation.

Left ventricular volume measurement by the conductance catheter and variations in the hematocrit in small animals.

Cardiac performance is quantitatively and continuously assessed from pressure-volume signals by using the conductance catheter technique even in small animals. Conductivity of blood, however, is dependent on hematocrit (Hct). Interdependence between hematocrit and volume measurement by the conductance catheter has been evaluated. In 12 male Wistar rats weighing 400-475 g, anesthetized and artificially ventilated, Hct was gradually lowered by isovolumic hemodilution ranging from 50% to 7%. Heparinized blood samples were drawn at decreasing Hct levels for centrifugation, for automated Hct measurement by a blood gas analyzer, and for conductance catheter volume measurements (CCV) in calibrated cuvettes. Substitution of about 2 ml colloid solution lowered the Hct initially from 47 +/- 2% to 36 +/- 3%; at the same time, CCV output rose by 36 +/- 14% for definite blood volume. There is a strong inverse linear relationship (absolute value of r > 0.96; P < 0.0001) between relative volume units (RVU) displayed by the volume acquisition device and the hematocrit for any calibrated blood cuvette. Slopes of the regression lines increase proportionally to the calibration volumes (28.3 microl: -0.25; 63.6 microl: -0.57; 113.1 microl: -0.92). These data document the direct interdependence between Hct and CCV. Consequently, careful Hct correction of the RVU recordings is necessary especially in small animals where even small amounts of substituted solutions result in a marked decrease in Hct and, thus, in pronounced blood volume misreadings.

Occasional single beat regurgitation observed with the medtronic advantage bileaflet heart valve.

BACKGROUND: The purpose of this clinical study was to obtain further evidence of the underlying mechanism causing the echocardiographically detected phenomenon of single beat regurgitation in a new bileaflet heart valve. As part of a prospective multicenter trial at our institution, 63 patients received the Advantage bileaflet mechanical heart valve (Medtronic, Minneapolis, Minnesota) in aortic position. During routine follow-up performed at discharge and annually after the operation, intermittent moderate transvalvular regurgitation was detected by echocardiography in 5 patients. METHODS: Fluoroscopy of leaflet motion (n = 4), invasive blood pressure measurements in the ascending aorta (n = 3) and digital phonocardiography (n = 5) was obtained in the patients showing an intermittent regurgitation during echocardiography. RESULTS: Valve thrombosis, sutures, or pannus ingrowth impairing valve closure was not detected. Fluoroscopy of leaflet motion showed intermittent incomplete closure of either one of the two leaflets in the same prosthesis. This could be correlated with a distinct diastolic blood pressure drop in the same cardiac cycle. Digital phonocardiography showed pathologic closure sounds in those cycles in which echocardiographically the intermittent regurgitation was observed. CONCLUSIONS: Some patients with the Medtronic Advantage prosthesis in the aortic position show an intermittent inability of complete valve closure that leads to a single beat transvalvular regurgitation. As thrombotic or other material that might cause a disturbance of leaflet motion could not be detected, and the patients seem not to be exposed to any risk except for some chronic regurgitant volume, we decided not to replace the prostheses.

The Mosaic bioprosthesis in the aortic position: seven years' results.

BACKGROUND AND AIM OF THE STUDY: The Mosaic bioprosthesis is a stented porcine aortic valve, which combines glutaraldehyde fixation with zero-pressure and root-pressure techniques and anti-mineralization treatment with amino-oleic acid for improved hemodynamics and tissue durability. The study aim was to collect intermediate-term data of the Mosaic bioprosthesis in the aortic position, the first device having been implanted in February 1994 at the authors' institution. METHODS: A total of 100 patients (49 females, 51 males) underwent aortic valve replacement with the Mosaic bioprosthesis between February 1994 and May 1999. Mean age at implant was 73.4 +/- 7.3 years. Concomitant procedures were performed in 40.0% of cases. Patients were followed up within 30 days postoperatively, after six months, and at annual intervals thereafter. Mean follow up was 3.8 years (range: 0.1-7.1 years); total follow up was 383.1 patient-years (pt-yr) and 100% complete. RESULTS: Early mortality (< or = 30 days) was 3.0%; late mortality was 4.6%/pt-yr, including a valve-related mortality of 0.6%/pt-yr. Freedom from event at seven years was 96.8 +/- 1.8% for thromboembolic events, 97.2 +/- 2.0% for thrombosed bioprosthesis, 96.6 +/- 2.6% for structural valve deterioration, 98.2 +/- 1.8% for nonstructural dysfunction, 95.9 +/- 2.0% for anti-thromboembolic hemorrhage, 98.9 +/- 1.1% for endocarditis, and 93.9 +/- 3.2% for reoperation/explant. After one year, the mean systolic pressure gradient was 15.3 +/- 6.7, 14.5 +/- 5.7, 12.7 +/- 4.1 and 12.9 +/- 4.8 mmHg for 21, 23, 25 and 27 mm valves respectively; the effective orifice area (EOA) was 1.4 +/- 0.4, 1.7 +/- 0.4, 1.8 +/- 0.4 and 2.6 +/- 0.4 cm2 for 21, 23, 25 and 27 mm valves respectively; and the EOA index was 0.8 +/- 0.3, 0.9 +/- 0.2, 0.9 +/- 0.2 and 1.3 +/- 0.1 cm2/m2 respectively. The mean left ventricular mass index was decreased significantly, from 159.7 +/- 56.8 g/m2 to 137.3 +/- 40.8 g/m2, for all valve sizes after one year. CONCLUSION: Clinical and hemodynamic performance of the Mosaic bioprosthesis was highly satisfactory during the first seven years after clinical introduction.

Left ventricular mass regression after aortic valve replacement with the mosaic bioprosthesis.

BACKGROUND AND AIMS OF THE STUDY: The study aim was to evaluate the hemodynamic performance and extent of left ventricular (LV) mass regression after aortic valve replacement (AVR) with the Mosaic bioprosthesis within the first postoperative year. METHODS: Between 1994 and 1999, 366 patients (203 males, 163 females) underwent AVR with the Mosaic bioprosthesis at five centers in Europe. Mean age at implant was 71.1 years (range: 34.5-86.8 years). LV mass assessment and hemodynamic evaluation were performed using transthoracic echocardiography within six days postoperatively, after six months, and at annual intervals thereafter. RESULTS: LV mass index decreased significantly in patients with valve sizes 21 to 27 mm, from 184.4+/-56.2 g/m2 postoperatively to 157.3+/-45.5 g/m2 after one year (14.7% decrease). The 19-mm valve group did not show significant LV mass index reduction (from 210.4+/-39.4 to 195.0+/-59.4 g/m2; 7.3%). Patients with significant LV mass index regression had survival benefits after seven years. Mean pressure gradients after one year were 16.0+/-4.3, 14.2+/-5.4, 12.8+/-5.3, 11.1+/-4.0 and 10.5+/-3.7 mmHg for 19, 21, 23, 25 and 27 mm valves, respectively. CONCLUSION: Implantation of the Mosaic bioprosthesis resulted in a significant regression of LV mass for the valves sizes 21 to 27 mm, corresponding to very low pressure gradients for a stented bioprosthesis.

European experience with the Mosaic bioprosthesis.

OBJECTIVE: The purpose of this study was to prospectively evaluate the clinical and hemodynamic performance of the Mosaic bioprosthesis (Medtronic, Inc, Minneapolis, Minn). METHODS: The stented porcine bioprosthesis combines the amino-oleic acid antimineralization treatment and the zero-pressure differential fixation technique for improved tissue durability. From February 1994 to May 1999, a total of 561 patients underwent valve replacement with the Mosaic bioprosthesis at 5 centers in Europe: 461 in the aortic and 100 in the mitral position. There were 261 women and 300 men; mean age at implantation was 70 years (range, 23-89 years). Mean follow-up was 2.9 years (range, 0-6.2 years), with a total follow-up of 1710.1 patient-years. RESULTS: Postoperative mortality was 4.2% per patient-year, including a valve-related mortality of 0.4% per patient-year. The freedom from event rates in the aortic position at 5 years and in the mitral position at 4 years were, respectively, 96.6% +/- 1.1% and 94.9% +/- 3.3% for primary thromboembolism, 96.4% +/- 5.0% and 87.1% +/- 4.8% for antithromboembolic-related hemorrhage, 99.1% +/- 0.5% and 100% for thrombosed prosthesis, 98.8% +/- 1.2% and 100% for structural valve deterioration, 98.8% +/- 0.7% and 100% for nonstructural dysfunction, 98.4% +/- 0.6% and 94.4% +/- 3.8% for endocarditis, and 95.4% +/- 1.6% and 95.3% +/- 3.7% for explant and reoperation. Mean pressure gradient values at 5 years ranged from 7.5 to 15.9 mm Hg in the aortic position and at 4 years from 2.0 to 6.9 mm Hg in the mitral position across all valve sizes. CONCLUSIONS: Clinical and hemodynamic performance of the Mosaic bioprosthesis were very satisfactory during the first 6 years after clinical introduction.