High-risk pulmonary embolism with out-of-hospital cardiac arrest: Acute multidisciplinary approach leading to surgical embolectomy with good clinical outcome.

Percutaneous pulmonary angiography may be used for early diagnosis of pulmonary embolism in the hemodynamic unstable patient. Pulmonary embolectomy is an effective treatment option in patients with acute high-risk pulmonary embolism.

Giant unruptured aneurysm of the left coronary sinus of Valsalva presenting as acute coronary syndrome: a case report.

BACKGROUND: Sinus of Valsalva aneurysm (SVA) is a rare cardiac anomaly that can be congenital or acquired. Unruptured aneurysms may be asymptomatic but can present as malignant arrhythmias, acute chest pain, and even sudden cardiac death. Both ruptured and unruptured SVAs may have fatal complications, thus prompt diagnosis and surgery is critical. CASE SUMMARY: We report a successful surgical repair of an unruptured aneurysm of the left sinus of Valsalva presenting as acute coronary syndrome. Coronary angiography (CAG) and cardiac multislice computed tomography (CT) revealed a large unruptured aneurysm of the left sinus of Valsalva. Surgical repair was performed by resection of the aneurysm, aortic valve replacement with composite graft, and coronary artery bypass. DISCUSSION: Aneurysm of the left sinus of Valsalva is an extremely rare condition. Correct diagnosis can be done by echocardiography, CAG, or CT. Non-ruptured aneurysms should be surgically repaired if they are associated with significant symptoms or if their size enlarge rapidly.

[Transcatheter aortic valve implantation in Denmark].

During the latest decade, transcatheter aortic valve implantation (TAVI) has evolved from being indicated only in patients with severe aortic stenosis and prohibitive or high surgical risk, to be an alternative to surgical aortic valve replacement in patients with intermediate surgical risk. Improvements of the peri-procedural management have resulted in marked reduction of complications and an increasing number of patients treated with TAVI every year in Denmark. By a minimalist approach, TAVI can be performed in local anesthaesia, with same day mobilisation and discharge within few days, without affecting the safety.

Aortic valve and left ventricular outflow tract calcium volume and distribution in transcatheter aortic valve replacement: Influence on the risk of significant paravalvular regurgitation.

OBJECTIVES: We sought to determine the impact of aortic root calcium on the risk of significant paravalvular regurgitation (sPAR) in transcatheter aortic valve replacement (TAVR). METHODS: In 302 consecutive patients from 3 centers, aortic root calcium was quantified volumetrically on pre-TAVR multidetector computed tomography (MDCT) in three regions: 1) the aortic valve region, 2) the overall left ventricular outflow tract (LVOT) and 3) the upper LVOT. Transcathether heart valve (THV) oversizing was calculated as (THV nominal area/MDCT annular area-1) × 100. The study endpoint sPAR was a composite of post-dilatation (PD) and PAR > mild. RESULTS: sPAR occurred in 15% (46/302) of patients. Upper LVOT calcium volume was more predictive of sPAR than overall LVOT calcium volume, with an area under the receiver operating curve (AUC) (95% confidence interval [CI]) of 0.80 (0.67-0.89) vs. 0.60 (0.51-0.70); p = 0.0001. The optimal cut-off calcium volume thresholds determined from receiver operating curves were 21 mm3 and 30 mm3 for upper LVOT and overall LVOT calcium, respectively. Upper LVOT calcium ≥ 21 mm3, but not overall LVOT calcium ≥ 30 mm3, independently predicted sPAR, odds ratio (95%CI): 9.5 (4.1-22.3) vs 1.6 (0.6-2.7). Upper LVOT calcium was more predictive of sPAR in patients with THV oversizing ≥ 13% compared to patients with THV oversizing <13%, AUC (95% CI): 0.83 (0.72-0.93) vs. 0.67 (0.51-0.74); p < 0.0001. CONCLUSIONS: Upper LVOT calcium predicts more-than-mild paravalvular regurgitation following TAVR or the need for postdilatation. Upper LVOT calcium is most predictive of paravalvular regurgitation in the event of THV oversizing ≥ 13%.

High-pressure balloon fracturing of small dysfunctional Mitroflow bioprostheses facilitates transcatheter aortic valve-in-valve implantation.

AIMS: Transcatheter valve-in-valve (VIV) implantation is usually discouraged in small surgical tissue valves. We report our first ten cases of fracturing small dysfunctional Mitroflow bioprostheses by high-pressure balloon dilatation to increase the internal diameter of the surgical valve before VIV (BF-VIV). METHODS AND RESULTS: BF-VIV was performed in 10 patients (mean age 84±4 years) with failing Mitroflow valves size 19 mm (n=3, threshold of fracture 15 atm) and 21 mm (n=7, threshold of fracture 13 atm). An Edwards SAPIEN 3 or XT 20 mm or 23 mm transcatheter valve was implanted inside the fractured Mitroflow bioprosthesis. The procedure improved aortic valve area (0.7±0.3 vs. 1.1±0.3 cm2, p=0.001), reduced peak aortic valve gradient (66±27 vs. 29±7 mmHg, p=0.002), resolved aortic regurgitation and improved patients' NYHA functional class (p=0.005). One patient had a minor stroke with complete resolution of symptoms and another patient required a pacemaker due to AV block. All patients were still alive at the end of follow-up (438±255 days). CONCLUSIONS: Initial experience with transcatheter BF-VIV suggests that this method is feasible and safe, and that it improves aortic valve haemodynamics and clinical functional capacity. BF-VIV is a promising alternative to repeat surgery in patients with small failing Mitroflow bioprostheses.

Results from more than 20 years of surgical pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension in Denmark.

OBJECTIVES: Chronic thromboembolic pulmonary hypertension is a fatal disease if left untreated, and pulmonary endarterectomy (PEA) is the potentially curable treatment of choice. We aimed to estimate the current in-hospital mortality rate, complication rate and long-term survival for patients with chronic thromboembolic pulmonary hypertension undergoing PEA in Denmark. METHODS: All chronic thromboembolic pulmonary hypertension patients who underwent PEA in the period 1994 till 2016 were consecutively enrolled in our single-centre study. All patients were followed from PEA until death or end of study. Kaplan-Meier survival analysis was used to estimate the 3-, 5- and 10-year survival rates with 95% confidence interval (CI). RESULTS: In total, 239 patients were operated in the study period. A significant reduction in mean pulmonary arterial pressure from 48 mmHg to 33 mmHg, and pulmonary vascular resistance from 800 dynes s cm-5 to 289 dynes s cm-5, was observed during the first postoperative day after PEA. Overall, in-hospital mortality rate was 8.4%. A significantly lower mortality rate in the late decade (2005-2016) compared with the early decade (1994-2004) was observed (4.3% vs 22.6%, P < 0.001). In-hospital mortality during the last 5 years (n = 80) was 2.5%. Three-, 5- and 10-year survival rates were 84% (CI: 77.8-88), 77% (CI: 70.7-82.7) and 62% (CI: 53-69.1), respectively. The majority of patients improved in World Health Organization functional class from III/IV to I/II and significantly increased their 6-min walking distance. CONCLUSIONS: PEA in Denmark is associated with a low in-hospital mortality rate and significant improvements in both haemodynamics and exercise capacity. Long-term survival is excellent and similar to high-volume international centres.

Transcatheter aortic valve implantation in patients with small aortic annuli using a 20†mm balloon-expanding valve.

BACKGROUND: While transcatheter aortic valve implantation (TAVI) is established for treating high-operative risk surgical aortic valve replacement candidates, until recently the smallest transcatheter heart valve (THV) measured 23 mm, posing greater risk for annular rupture and THV failure in patients with aortic stenosis (AS) with small aortic annuli (≤20 mm). OBJECTIVES: In the setting of a multicentre registry, we report on the safety, efficacy and early clinical outcomes of the SAPIEN XT 20 mm balloon-expanding THV. RESULTS: Among TAVI 55 recipients (n=30 for native AS, n=25 for a valve-in-valve procedure (V-in-V)), median age and Society of Thoracic Surgeons score were 85 (81 to 87) years and 7.8 (4.7 to 12.4)%, respectively. Mean and minimum annular diameters were 19±1 and 17±2 mm, respectively, in native patients with AS, and 17±1 mm (internal diameter) in V-in-V recipients. Successful device implantation rate was 96%, with no procedural-related death. Overall in-hospital-30-day death, stroke and major bleeding rates were 5%, 2% and 9%, respectively. In native AS TAVI recipients, mean transaortic gradient decreased from 54±20 to 12±5 mm Hg (p<0.001), and from 45±17 to 24±8 mm Hg (p<0.001) in V-in-V recipients. Severe prosthesis-patient mismatch (PPM) rates were 10% and 48% in native AS and V-in-V TAVI recipients, respectively (p=0.03). Post-TAVI, the rate of moderate aortic regurgitation was 7% and 0% in native AS and V-in-V TAVI recipients, respectively. CONCLUSIONS: TAVI with the 20 mm SAPIEN XT THV appears safe and technically feasible, with acceptable short-term clinical outcomes and low rates of severe PPM in those with native AS.

Prosthetic valve endocarditis after transcatheter aortic valve implantation-diagnostic and surgical considerations.

Prosthetic valve endocarditis (PVE) after transcatheter aortic valve implantation (TAVI) or surgical aortic valve replacement (SAVR) is a potential life threatening complication. Better understanding of the incidence, predictors, clinical presentation, diagnostic measures, complications and management of PVE may help improve TAVI long-term outcome. We report a case of TAVI-PVE in an 80-year-old high risk patient in whom SAVR was successfully performed. We have reviewed literature regarding TAVI-PVE.

Health-related quality-of-life after transapical transcatheter aortic valve implantation.

PURPOSE: Transcatheter aortic valve implantation (TA-TAVI) is a well-established treatment for aortic valve stenosis in high-risk patients and indications have been continuously expanding to also include intermediate-risk patients. However, in low-risk patients, experiences are still sparse and although clinical outcomes have been shown favorable results, HRQoL has remained unexplored. The aim of this report was to describe the long-term health-related quality-of-life (HRQoL) in low-risk patients randomized to TA-TAVI or surgical aortic valve replacement (SAVR). METHODS: In a prospective, randomized trial, patients with aortic valve stenosis were randomized to either TA-TAVI or SAVR. TA-TAVI was performed through a mini thoracotomy with the introduction of prosthesis via the apex of the heart and antegradely advancement over the pre-dilated native valve. SAVR was performed during cardiopulmonary bypass with resection of the native valve and replacement with a prosthesis valve through a median sternotomy. Afterwards, patients were followed yearly with echocardiography and HRQoL assessment. RESULTS: A total of 58 patients were included; 29 patients for TA-TAVI and 29 patients for SAVR. The only difference in HRQoL was found in the physical component summary after 1 year; 44 ± 9 in the TA-TAVI group compared with 36 ± 9 in the SAVR group, p = .03. There were no differences in any of the remaining timepoints in neither physical nor mental component summary, p = .19 and p = .98, respectively, and there were no differences in survival during the 5 years. CONCLUSIONS: In low-risk patients with aortic valve stenosis undergoing TA-TAVI, no differences appeared in HRQoL compared with SAVR during a 5-year follow-up period.

Left ventricular global systolic longitudinal deformation and prognosis 1 year after femoral and apical transcatheter aortic valve implantation.

BACKGROUND: Aortic valve replacement is the recommended therapy for patients with severe aortic stenosis who have symptoms or decreased left ventricular (LV) function. Transcatheter aortic valve implantation (TAVI) is a treatment alternative in surgically high-risk or inoperable patients with severe aortic stenosis. The objective of this study was to analyze LV function assessed by global LV longitudinal systolic strain (GLS) and relation to prognosis in patients with severe aortic stenosis treated with femoral or apical TAVI. METHODS: Two-dimensional echocardiography was performed before and 1 year after TAVI. Ejection fraction (EF) was retrospectively measured using the biplane Simpson's method, and GLS was obtained as an average of 16 segments in the three standard apical views by speckle-tracking. GE Vivid 7 and Vivid 9 machines were used for echocardiography, and speckle-tracking analysis was performed using EchoPAC PC '08 version 7.0.1. RESULTS: The total population consisted of 100 TAVI patients. Eighty-one patients survived to 1-year follow-up, with a mean age of 81 ± 7 years (range, 64-93 years) and a mean European System for Cardiac Operative Risk Evaluation score of 9.6 ± 2.7. Nineteen patients died before 1-year follow-up (12 women), with a mean age of 82 ± 7 years (range, 66-92 years) and a mean European System for Cardiac Operative Risk Evaluation score of 10.5 ± 2.8. No differences were found between the 19 patients who died before follow-up and the 81 patients who survived to 1-year follow-up. GLS was increased significantly 1 year after TAVI. In 34 patients with EFs > 50%, GLS increased from -15.3 ± 3.4 to -17.1 ± 3.6 (P = .04). In these patients, the mean EF increased numerically from 57.9 ± 5.3% to 60 ± 7.7% (P = .19). In 74 patients with EFs ≤ 50%, mean GLS and EF improved significantly from -10 ± 2.8 to -13.8 ± 3.8 (P < .0001) and 39 ± 9.4% to 52 ± 12.5% (P < .0001), respectively. The 1-year gain in EF was the same after femoral TAVI (9.7 ± 10.1%) and after apical TAVI (8 ± 10.8%) (P = .52). Furthermore, GLS did not differ significantly after femoral and apical TAVI (-3.8 ± 3.3 and -2.6 ± 3.7, respectively, P = .21). There was no difference in causes of death according to approach. In the total population (n = 100), 35 deaths occurred, 19 before 1-year follow-up and 16 afterward. The median follow-up time was 30 months. Twenty-five patients (71%) died from cardiac causes. Overall 1-year mortality was 19%, and overall 2-year mortality was 28%. In the patients who died, the median survival time in the apical group was 28.5 ± 15.4 months, compared with 31.6 ± 19 months in the femoral group (P = .47). There was no impact on prognosis according to high (≥47.5%) versus low (<47.5%) baseline EF or high (≥11.95%) versus low (<11.95%) baseline GLS. However, the magnitude of changes in GLS seemed to have a prognostic impact. CONCLUSIONS: LV EF and longitudinal systolic deformation were improved in TAVI independent of technical approach using the Edwards SAPIEN valve prosthesis during 1-year follow-up. The mortality rate was comparable between technical approaches and independent of baseline LV function. However, patients with the greatest improvement in LV systolic longitudinal deformation after TAVI had a lower mortality rate.

Aortic regurgitation after transcatheter aortic valve implantation of the Edwards SAPIEN ™ valve.

INTRODUCTION: Transcatheter aortic valve implantation (TAVI) is established as an attractive treatment option for high-risk patients with aortic valve stenosis. One concern is the high risk of prosthetic valve regurgitation. This study aimed to examine for potential preoperative risk factors for postprocedural transcatheter heart valve regurgitation and to quantify the risk, degree, and consequences of postprocedural regurgitation. MATERIALS AND METHODS: 100 consecutive patients who underwent femoral (n = 22) or transapical (n = 78) TAVI were retrospectively reviewed. Echocardiographic valve regurgitation and clinical parameters were analyzed over the first year after TAVI. RESULTS: Seventy-five percent of all patients had prosthetic valve regurgitation. It was, however, only mild or absent in 64% of patients and did not require re-intervention in any of the patients in the series. The severity of the regurgitation appeared unchanged over the one-year follow-up period. Moderate to severe regurgitation was associated with significant yet stable dilatation of the left ventricle over one year and lesser NYHA class improvement three months after TAVI. Asymmetrical native valve calcification increased the risk of paravalvular regurgitation non-significantly. CONCLUSION: Transcatheter heart valve regurgitation seems to be mild in the majority of cases and unchanged over a 12 months follow-up period. While affecting left ventricular dimensions in moderate or severe cases, we observed no obvious undesirable consequences of the prosthetic valve regurgitation within the first year.

Aortic root distensibility after subcoronary stentless valve implantation.

BACKGROUND AND AIM OF THE STUDY: The preservation of aortic root dynamics is considered important for the durability of aortic valve bioprostheses. Stentless heart valves are believed to support physiologic biomechanics. To date, dynamic analysis has been limited to the full root prosthesis, and exclusively in the radial direction. The study aim was to investigate and compare the radial and longitudinal aortic root distensibilities of subcoronary stentless valves, and of stented and native pig valves. METHODS: Stented pericardial (Mitroflow) or stentless (Solo, Toronto SPV) valve prostheses, or native porcine valves, were investigated in 32 pigs. Postoperatively, 12 sonomicrometry crystals were placed on the aortic root in order to measure aortic root distensibility, in both radial and longitudinal directions. RESULTS: Sonomicrometry data were obtained from 23 pigs (72%). At the annular level, the native and Solo valves were significantly more distensible in a radial direction than the Mitroflow valve (p = 0.04). However, at the level of the sinotubular junction (STJ), commissures and aorta, the native valve was significantly more distensible than all of the artificial valves (p = 0.006, p = 0.006, and p = 0.02, respectively). The Solo valve exhibited less longitudinal distensibility than the Toronto SPV and Mitroflow valves. The Toronto SPV initiated a radial expansion at the STJ significantly later in the cardiac cycle than did both the Solo and native valves (p = 0.03), but showed no difference compared to the Mitroflow valve. Longitudinal expansion between the annulus and the STJ started significantly earlier for the Solo valve than for both the Toronto SPV (p = 0.03) and Mitroflow (p = 0.02) valves. CONCLUSION: The Solo valve proved to be superior in maintaining annular distensibility immediately following implantation when compared to the Mitroflow valve. The Solo valve did not, however, preserve longitudinal distensibility as well as the other investigated valves. Finally, the Solo valve appeared to provide a more physiologic aortic root expansion pattern than its prosthetic counterparts.

Turbulence downstream of subcoronary stentless and stented aortic valves.

Regions of turbulence downstream of bioprosthetic heart valves may cause damage to blood components, vessel wall as well as to aortic valve leaflets. Stentless aortic heart valves are known to posses several hemodynamic benefits such as larger effective orifice areas, lower aortic transvalvular pressure difference and faster left ventricular mass regression compared with their stented counterpart. Whether this is reflected by diminished turbulence formation, remains to be shown. We implanted either stented pericardial valve prostheses (Mitroflow), stentless valve prostheses (Solo or Toronto SPV) in pigs or they preserved their native valves. Following surgery, blood velocity was measured in the cross sectional area downstream of the valves using 10MHz ultrasonic probes connected to a dedicated pulsed Doppler equipment. As a measure of turbulence, Reynolds normal stress (RNS) was calculated at two different blood pressures (baseline and 50% increase). We found no difference in maximum RNS measurements between any of the investigated valve groups. The native valve had significantly lower mean RNS values than the Mitroflow (p=0.004), Toronto SPV (p=0.008) and Solo valve (p=0.02). There were no statistically significant differences between the artificial valve groups (p=0.3). The mean RNS was significantly larger when increasing blood pressure (p=0.0006). We, thus, found no advantages for the stentless aortic valves compared with stented prosthesis in terms of lower maximum or mean RNS values. Native valves have a significantly lower mean RNS value than all investigated bioprostheses.

Transatrial stent-valve implantation in a stenotic tricuspid valve bioprosthesis.

A 69-year-old man presented with symptoms of right heart failure due to stenosis of a tricuspid valve bioprosthesis. Echocardiography revealed right atrial dilatation and an estimated tricuspid valve area of 0.4 cm2. Because of advanced poor general condition and comorbidities, he was found unfit for conventional reoperation. Instead, transcatheter transatrial stent-valve implantation through a right thoracotomy was scheduled. The procedure resulted in a markedly improved clinical condition and an increased valve area measured to 2.5 cm2. In conclusion, transcatheter transatrial stent-valve implantation in stenotic valves is technically feasible and may lead to substantial improvement of the clinical condition.

Single center experience with transcatheter aortic valve implantation using the Edwards SAPIEN™ Valve.

OBJECTIVES: The use of transcatheter aortic valve implantation (TAVI) for high-risk patients was introduced in the early 2000s for treatment of aortic valve stenosis patients with too high surgical risk. During the last years, there has been a dramatic increase in TAVI procedures. TAVI programs are implemented in numerous cardiac centers. This paper describes a single center experience with its first 100 TAVI procedures. METHODS: This study included the first 100 patients who were scheduled for either transfemoral (F-TAVI) or transapical (A-TAVI) aortic valve implantation at Aarhus University Hospital, Skejby, using the Edwards SAPIEN™ valve. The indication for TAVI was unacceptable high predicted risk associated with conventional surgery. Patients with adequate diameter of iliac arteries were scheduled for F-TAVI, otherwise A-TAVI was preferred. RESULTS: The patients were treated between February 2006 and June 2010. Of these were 44% males and 56% females with a mean (S.D.) age of 81 (7.0). Thirty-days mortality rate was 8%, and decreased from 12% among the first 50 patients to 4% for the last 50 patients. Successful implantation was achieved in 92% patients. Major non-fatal complications were seen in 5% of 76 A-TAVI and in 0% of 24 F-TAVI patients. Mean (S.D.) EuroSCORE in the F-TAVI and A-TAVI groups was 15.9 (9.4) and 21.5 (14), respectively (p = 0.06). Post-procedural leakage of cardiac biomarkers was significantly higher in the A-TAVI group as compared to in the F-TAVI group. Mean (S.D.) NYHA class improved from 2.9 (0.6) to 1.8 (0.7) p < 0.001, with no significant difference between A-TAVI and F-TAVI patients. CONCLUSION: In surgically non-amenable patients, TAVI can be performed with acceptable mortality and morbidity and results in marked functional improvement. A decrease in 30-day mortality over time indicated a learning curve when implementing this treatment.

Leaflet opening and closing dynamics of stentless bioprostheses.

BACKGROUND AND AIM OF THE STUDY: Stiffening of the aortic root may entail asynchronous aortic leaflet movement, and result in enhanced flexion-stress in specific areas of the cusps. As stentless prostheses are more flexible than their stented counterparts, they are more likely to exhibit physiologic leaflet movements. The study aim was to compare leaflet movement dynamics in stented versus non-stented aortic valves implanted in pigs. METHODS: Aortic bioprostheses were implanted surgically into adult pigs as follows: stented Mitroflow (n = 6), stentless Solo (n = 5), and stentless Toronto SPV (n = 4). In five control animals, the native aortic valve leaflets were untouched. Postoperatively, the aortic valve was displayed by epicardial echocardiography. M-mode display of the non-coronary leaflet was applied to assess rapid valve-opening velocity (V(open)) and rapid valve-closing velocity (V(close)). RESULTS: The mean V(open) values were 29.2, 25.5, 37.8, and 31.9 cm/s, respectively, for the native, Toronto SPV, Solo, and Mitroflow valves. The mean V(close) values were 23.2, 21.9, 34.1, and 34.3 cm/s, respectively. A comparison of V(open) values showed no statistically significant difference between the valves. The Mitroflow and Solo valves yielded significantly higher V(close) values than the native and Toronto SPV valves. The Toronto SPV exhibited marked systolic leaflet folding. CONCLUSION: The stent of a bioprosthetic valve does not appear to affect leaflet velocities when compared to the stentless bioprosthetic valve. The Solo and Mitroflow valves closed more abruptly than the porcine native aortic valve; however, the Toronto SPV valve displayed diverging systolic leaflet movement patterns.

In-vivo blood velocity and velocity gradient profiles downstream of stented and stentless aortic heart valves.

BACKGROUND AND AIM OF THE STUDY: Abnormal flow conditions across aortic bioprosthetic valves may result in degenerative processes. Thus, it is important to implant biological valve prostheses with velocity profiles similar to those of native valves. The study aim was to compare blood velocity and velocity gradient profiles downstream of stented and stentless aortic valves implanted in pigs, and in native porcine valves. METHODS: Stented valve prostheses (Mitroflow, n = 7) or stentless valve prostheses (Solo, n = 5 or Toronto SPV, n = 7) were implanted into pigs; the native valve was retained in eight animals. After weaning the animals from cardiopulmonary bypass, cardiac magnetic resonance imaging was performed to determine the blood velocities and velocity gradient profiles. RESULTS: The native valves had a significantly lower peak velocity (92 +/- 26 cm/s) than the artificial valves (Solo: 247 +/- 107 cm/s; Toronto: 252 +/- 41 cm/s; Mitroflow: 229 +/- 18 cm/s). The native valves exhibited a flat velocity profile during systole, whereas the Solo valve, and especially the Toronto SPV valve, displayed more parabola-shaped velocity profiles; velocity profiles downstream of the Mitroflow valve exhibited a flat shape. The native valves had a lower mean velocity gradient at peak systole (p < 0.0001). The velocity gradient percentage above mean was lowest for the native valve (0.14 +/- 0.11; p < 0.0001), while the Mitroflow valve had a percentage of 0.57 +/- 0.09, which was lower than the Solo valve (0.69 +/- 0.12; p = 0.074), and significantly lower than the Toronto valve (0.70 +/- 0.08; p = 0.015). All valves displayed high velocity gradients adjacent to the aortic wall; in particular, the Toronto SPV which also had high velocity gradients at the center of the vessel. CONCLUSION: All of the artificial valves tested had a significantly higher mean velocity gradient and peak velocity than the native valves. However, the Mitroflow had a mean velocity and a velocity gradient percentage lower than the two stentless valves. The Solo and Mitroflow valves displayed velocity profiles most like native valves, while the Toronto valve had a more irregular asymmetric velocity profile.