HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Walter B. Eichinger Sabine Bleiziffer Ralf Guenzinger Robert Bauernschmitt Ruediger Lange Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wagner, I. M. Articles by Lange, R. Search for Related Content PubMed PubMed Citation Articles by Wagner, I. M. Articles by Lange, R.

J Thorac Cardiovasc Surg 2007;133:1234-1241
© 2007 The American Association for Thoracic Surgery

Surgery for Acquired Cardiovascular Disease

Influence of completely supra-annular placement of bioprostheses on exercise hemodynamics in patients with a small aortic annulus

German Heart Center Munich, Clinic of Cardiovascular Surgery, Munich, Germany.

Received for publication August 3, 2006; revisions received October 10, 2006; accepted for publication October 23, 2006.

^_* Address for reprints: Ina M. Wagner, MD, Deutsches Herzzentrum München, Klinik für Herz-und Gefäßchirurgie, Lazarettstr. 36, D-80636 München. (Email: wagner{at}dhm.mhn.de).

	Abstract

Top Abstract Introduction Materials and Methods Results Discussion Conclusions References

 
Objective: Aortic valve replacement in patients with a small aortic annulus is often associated with increased pressure gradients. For this reason, prostheses for completely supra-annular placement have been developed. To evaluate the potential benefit of this design, the present study compared the effectiveness of 1 intra–supra-annular bioprosthesis and 3 completely supra-annular bioprostheses in patients with an aortic annulus diameter of 23 mm or less.

Methods: Between August 2000 and December 2004, each of 192 patients requiring aortic valve replacement with an intraoperatively measured aortic annulus diameter of 23 mm or less received one of the following bioprostheses: the stented bovine Sorin Soprano bioprosthesis (n = 28) (Sorin Group, Saluggia, Italy), the Carpentier–Edwards Perimount bioprosthesis (n = 50) (Edwards Lifesciences, Irvine, Calif), the Carpentier–Edwards Perimount Magna bioprosthesis (n = 70) (Edwards Lifesciences), or the stented porcine Medtronic Mosaic (n = 44) (Medtronic Inc, Minneapolis, Minn) bioprosthesis. After 6 months, hemodynamic data at rest and during exercise were obtained by echocardiography in 142 patients.

Results: The pericardial valves showed lower mean systolic pressure gradients, larger effective orifice areas and indices, and superior effective orifice fractions than did the porcine valve (P < .05) (Carpentier–Edwards Perimount: 10.9 ± 3.6 mm Hg, 1.59 ± 0.41 cm², 0.9 ± 0.25 cm²/m², 41.9% ± 9.6%; Carpentier–Edwards Perimount Magna 10.1 ± 3.8 mm Hg, 1.64 ± 0.38 cm², 0.93 ± 0.22 cm²/m², 45.1% ± 10.2%; Sorin Soprano 13.5 ± 5.0 mm Hg, 1.64 ± 0.32 cm², 0.92 ± 0.15 cm²/m², 45.8% ± 9.0%; vs Medtronic Mosaic 15.5 ± 5.2 mm Hg, 1.31 ± 0.42 cm², 0.75 ± 0.24 cm²/m², 35.2% ± 10.0%, respectively). The lowest mean systolic pressure gradients were found after the implantation of the Carpentier–Edwards Perimount Magna. Effective orifice areas, indices, and fractions of the pericardial valves did not show significant differences.

Conclusions: In patients with small aortic roots, transvalvular gradients and effective orifice area showed a tendency to superior results in pericardial valves compared with the porcine bioprosthesis. However, the completely supra-annular design does not necessarily lead to superior hemodynamic results compared with the intra–supra-annular position.

	Introduction

Top Abstract Introduction Materials and Methods Results Discussion Conclusions References

 
Even with the most sophisticated design of prostheses for aortic valve replacement, a residual pressure gradient may remain, especially in patients with a small aortic annulus or aortic root.

A new concept for optimizing hemodynamic performance is the construction of prostheses that are designed for completely supra-annular implantation. The stent material of completely supra-annular valves is placed on top of the sewing ring. Ventriculoarterial mattress sutures combined with the new design theoretically ensure that stent and sewing ring material do not reach the outflow tract, thus impairing the flow of blood. This design was first implemented in the Medtronic Mosaic (Medtronic Inc, Minneapolis, Minn) bioprosthesis, followed by the Carpentier–Edwards Perimount Magna (Edwards Lifesciences, Irvine, Calif) and Sorin Soprano (Sorin Group, Saluggia, Italy) bioprostheses.

This study evaluates the systolic pressure gradients and effective orifice areas (EOA) of these valves in patients with a small aortic annulus at rest and during exercise, and analyzes the potential hemodynamic benefit resulting from completely supra-annular placement. As a reference valve with an intra–supra-annular design, the Carpentier–Edwards Perimount (Edwards Lifesciences) pericardial prosthesis was included.

For hemodynamic comparisons of different tissue prostheses, the labeled valve sizes may not be suitable, because there is a discrepancy between geometric dimensions and valve size labeling by different companies.^1-4 The bias that is caused by using the labeled valve size can be avoided by using an independent index for all valve types, which refers to the intraoperatively measured aortic annulus area and the valve’s hemodynamic performance. The independent index we use is the effective orifice fraction (EOF), which was previously introduced by our group.³

	Materials and Methods

Top Abstract Introduction Materials and Methods Results Discussion Conclusions References

 
Bioprostheses
The Carpentier–Edwards Perimount (Perimount) valve is a stented bovine pericardial bioprosthesis for intra–supra-annular implantation. It received Food and Drug Administration approval in 1991. High rates of freedom from valve-related adverse events have been shown in long-term studies.⁵

The Carpentier–Edwards Perimount Magna (Magna) valve is a stented bovine pericardial bioprosthesis. The valve corresponds to the Perimount in terms of tissue preparation and prosthetic material, but it has been modified to permit completely supra-annular placement. In addition, this valve has a reduced sewing ring. The Magna prosthesis has been in clinical use since September 2002.

The Medtronic Mosaic (Mosaic) valve is a stented porcine bioprosthesis. It has been in clinical use in Europe since 1994 and in the United States since 2000 and has exhibited high rates of freedom from adverse events in midterm follow-up studies.^6-8

The Sorin Soprano (Soprano) valve is a stented bovine bioprosthesis. In terms of tissue preparation and prosthetic material, it corresponds to the Sorin Pericarbon More, which has been in clinical use for more than 15 years⁹ but differs in stent design. It is designed to permit completely supra-annular implantation to improve hemodynamic performance. It has been in clinical use since August 2003.

Surgical Procedure and Measurement of the Aortic Annulus With a Universal Metric Sizer
Aortic valve replacement was performed using standard cardiopulmonary bypass with moderate hypothermia at 32°C with cold crystalloid cardioplegic cardiac arrest. After removal of the native aortic valve and decalcification of the aortic annulus and root, the internal diameter of the aortic annulus was routinely measured by inserting a probe (Hegar dilator) into the annulus (unit: 1 mm). With the assumption that the aortic annulus approaches a circular shape, the annulus orifice area was calculated as follows: (Hegar dilator’s diameter [cm] x 0.5)² x . The prosthetic valve size was determined by using the original sizer provided by each manufacturer. All bioprostheses were implanted with pledgeted, interrupted, non-everting mattress sutures.

Completely Supra-annular Placement
Completely supra-annular placement is achieved by using ventriculoarterial mattress sutures combined with the new valve design, in which the stent is placed on top of the sewing ring and not beside the sewing ring.

Patient Enrollment and Follow-up
Between August 2000 and December 2004, 192 patients with an aortic stenosis or combined aortic lesion diagnosis requiring valve replacement entered the study. Only patients with an intraoperatively measured aortic annulus diameter of 23 mm or less were included in this prospective, nonrandomized study, irrespective of the labeled valve size of the implanted prosthesis. Fifty patients received the Perimount valve, 70 patients received the Perimount Magna valve, 44 patients received the Mosaic valve, and 28 patients received the Soprano valve. At our institution, the 4 tested valves were not all on hand at the same time during the whole period of the study. The Mosaic and Perimount valves have been used since August 2000. They were followed by the Magna in January 2001 and the Soprano in September 2003. We included the patients consecutively to avoid bias by patient selection; the consequence is the variance in group size. The valve type was chosen according to the surgeon’s preference. All patients gave informed consent to participate in the study. The study was approved by the local ethics committee. Concomitant procedures were allowed, except for valve replacement in another position. Patients requiring valve replacement for acute endocarditis or emergency cases were not included in the study. Body surface area, aortic annulus diameter, and patient age and gender at the time of operation are summarized in Table 1. There is no significant difference between the groups.

The reasons for nonattendance at the follow-up examination are given in Table 2. There is no difference between the groups who finally underwent the stress test (Table 3).

The EOA was calculated by using the continuity equation:

The effective orifice area index (EOAI [cm²/m²]) was calculated by dividing the EOA by body surface area (DuBois formula).¹¹

The EOF³ was used to compare the different valve types. This is the relation of Doppler-derived EOA to the anatomic annulus area measured intraoperatively.

EOF = Doppler-derived EOA [cm²]/anatomic annulus area [cm²].

Exercise Protocol
During bicycle exercise (Ergoline, ergometrics er900EL, Bitz, Germany), patients sat reclined in a 50-degree position. After the patients started exercise with a workload of 25 Watts, the workload was increased by 25 Watts every 2 minutes. The patients were encouraged to exercise until exhaustion. In case of unsatisfactory Doppler signals, the whole bicycle unit was tilted to the left side until optimal measurements were obtained. Measurements were performed at the end of each 2-minute workload level. Blood pressure was measured every 2 minutes using a sphygmomanometer cuff fixed on the right arm. A 12-lead electrocardiogram was continuously recorded. Exercising was stopped by the investigator in case of hypertension (blood pressure > 210/110 mm Hg), electrocardiogram changes as ST segment abnormalities, new arrhythmias (atrial fibrillation, premature ventricular complexes as couplets, bigemini, or trigemini), tachycardia with more than 120 beats/min, angina pectoris, or severe dyspnea.

Patient–Prosthesis Mismatch
According to Blais and colleagues,¹² patient–prosthesis mismatch (PPM) was defined as severe if the prosthetic aortic valve EOAI was 0.65 cm²/m² or less, as moderate if EOAI was greater than 0.65 cm²/m² and 0.85 cm²/m² or less, and as clinically not significant if EOAI was greater than 0.85 cm²/m². To calculate the rate of PPM, the body surface area and the Doppler-derived EOA were assessed 6 months postoperatively in every individual patient. EOAs for the prosthetic valves that are available in the literature or provided by the manufacturers were not used for reference.

Statistical Analysis
Statistical analysis was performed with the Statistical Package for the Social Sciences 14.0 for Windows (SPSS Inc, Chicago, Ill). Continuous data are presented as mean ± standard deviation. To compare categoric data, the chi-square test was used. To compare continuous data in more than 2 groups, the Kruskal–Wallis test was used. To detect differences between groups, analysis of variance with Bonferroni correction for multiple testing was applied.

	Results

Top Abstract Introduction Materials and Methods Results Discussion Conclusions References

 
Hemodynamic Results
Mean systolic pressure gradients and stroke volumes are shown in Figure 1. Gradients increased with every exercise level because of larger stroke volumes. The pericardial valves showed lower gradients compared with the porcine valve (P < .05). In addition, the Magna showed lower gradients than did the Soprano and Perimount (P < .05).

View larger version (36K): [in this window] [in a new window]   Figure 1. Mean systolic pressure gradients and stroke volumes at rest and during exercise.

View larger version (18K): [in this window] [in a new window]   Figure 2. EOF, the independent index for valve performance, of the stented bioprostheses as percentages in the diagram. The mean EOAs (inner black circle) in relation to the annulus areas (outer white circle). EOA, effective orifice area.

View larger version (18K): [in this window] [in a new window]   Figure 3. Incidence of PPM calculated with the Doppler-derived EOA 6 months postoperatively. severe PPM moderate PPM no PPM. PPM, Patient–prosthesis mismatch; EOA, effective orifice area.

	Discussion

Top Abstract Introduction Materials and Methods Results Discussion Conclusions References

 
Hemodynamic Performance
The systolic hemodynamic performance of the 3 bovine prostheses (Soprano, Magna, and Perimount) and the porcine (Mosaic) bioprosthesis corresponded to the outcome of other reports on these prosthetic heart valves.^6,8,13-17

Up to now there has been no direct in vivo comparison between the 3 bovine valves and the porcine valve at rest and during exercise. Assessment of hemodynamic variables during exercise may be more appropriate to study the performance of the valves,¹⁸ because it reflects more closely the situation in daily life.

Compared with the other prostheses, the Magna showed the lowest gradients at rest and during exercise. All 3 pericardial valves exhibited lower gradients compared with the porcine valve. We are aware that the measurement of gradients does not entirely represent the complex function of a valve. For this reason we think that in vitro studies (eg, Gerosa and associates¹⁹) performed with the same valves are absolutely necessary and complete our in vivo findings to describe variables such as stroke work loss, total regurgitant, and leakage volumes for the individual prostheses.

In most patients, stroke volume increases during mild exercise. Because of systolic or diastolic dysfunction, mitral valve disease, or elevated afterload and peripheral vascular resistance, the increase of stroke volume may be impaired, especially in elder patients. This could be an explanation for the missing increase of stroke volume at the 75-Watt level in the patients with the Perimount valve.

Comparison of Different Valve Types
The hemodynamic comparison of different prostheses is complicated by the fact that the labeled valve size does not reflect the same dimensions for each prosthesis and thus is not suitable as a basis for valve comparisons. Prostheses carrying the same labeled valve size may have a different effect on blood flow according to their individual geometric dimensions.^1,20 To correct for these differences in valve design, comparisons should be based on the EOF as an independent index of valve performance.³

In our series the pericardial valves showed a larger EOF compared with the porcine valve. Although the completely supra-annular design should result in an optimized functional use of the anatomically given annulus area, the intra–supra-annular Perimount shows lower mean pressure gradients than the Mosaic and Soprano and no significant difference in EOF compared with the completely supra-annular Soprano and Magna. In an in vitro study, Gerosa and colleagues¹⁹ compared 3 pericardial bioprostheses (Perimount Magna, Sorin Soprano, and Sorin Mitroflow) and 2 porcine bioprostheses (St Jude Medical Epic Supra [St Jude Medical Inc, St Paul, Minn] and Medtronic Mosaic) by using a pulse duplicator. Accordant to our findings, the pericardial valves showed lower pressure gradients and larger EOAs than those of the porcine valves. The authors take into account that a meaningful hemodynamic comparison of different valve types should not be based on industry-labeled valve sizes by comparing prostheses that can fit in a 21-mm pulse duplicator ring regardless of industry-labeled valve size. In vivo, the decision that leads to the selection of a certain valve size is additionally influenced by the complex anatomic structure of the aortic root in combination with prosthesis dimensions, including stent height, sewing ring diameter, completely supra-annular position, and anatomic relation to the coronary ostia (Figure 4).

View larger version (20K): [in this window] [in a new window]   Figure 4. Two aortic root anatomies with an identical TAD. A more bulbar-shaped root (right). This is the ideal situation for completely supra-annular placement in which the tissue annulus diameter corresponds to the internal orifice diameter of the prosthesis (TAD = IOD). Small aortic root (left). Despite the same tissue annular diameter, the valve of the same size (black) does not fit. Thus, the surgeon has to choose a smaller valve (white), with the consequence that despite implantation of a completely supra-annular prosthesis, the stent and sewing ring material impair the bloodstream because the shape of the aortic root does not allow the implantation of a valve large enough to ensure that the IOD corresponds to the TAD. This illustrates the hypothesis that a completely supra-annular prosthesis placement does not ensure a hemodynamic benefit in every aortic root. Even after implantation of a completely supra-annular prosthesis, flow obstruction caused by the stent and sewing ring material may occur if there is a narrow aortic root. TAD, Tissue annulus diameter; IOD, internal orifice diameter; ESRD, external sewing ring diameter.

In our opinion the EOA of an implanted valve is a functional parameter that probably depends on leaflet compliance, orientation, and position (angle) in relation to the LVOT and the ascending aorta. Thus, the EOA has to be assessed for every individual patient and his/her valve substitute. The easiest way to determine the EOA of an implanted valve is Doppler echocardiography with the use of hydrodynamic principles (continuity equation). However, because the Doppler-derived EOA depends on various hemodynamic conditions, it should not be determined just in the early postoperative period when patients may be still anemic; left ventricular function may not yet have been restored, and volume status may be disordered. In the present study, EOA and the occurrence of PPM were assessed 6 months postoperatively by means of Doppler EOA measurement. According to a literature survey by Pibarot and colleagues,²⁵ PPM is present in up to 20% to 70% of patients with a stented aortic bioprosthesis. In our series PPM ranged from 32% (Soprano) to 69% (Mosaic).

Completely Supra-annular Design
The new generation of stented bioprostheses for completely supra-annular placement is represented by the Magna, Mosaic, and Soprano valves in our series. This technical development aims at optimizing the systolic hemodynamic performance of any stented prosthesis. The EOF, which represents the use of the anatomically given annulus area, ranged from 35.2% (Mosaic) to 45.8% (Soprano) in our series. This reveals that despite the completely supra-annular design, the whole annulus area is not available for blood flow, presumably because the stent and sewing ring material are still positioned within the blood flow. Thus, the completely supra-annular design does not necessarily lead to superior hemodynamic results compared with the intra–supra-annular valve. Presumably, not every aortic root is anatomically suitable to exhibit the advantages of the completely supra-annular design. In a very straight aortic root, with little extension of the sinuses, even the completely supra-annular valve protrudes somewhat into the outflow tract. Figure 4 illustrates our hypothesis that even if a completely supra-annular prosthesis is used, flow obstruction caused by the stent and sewing ring material cannot always be avoided.

Limitations
Because our study was a nonrandomized study, bias resulting from patient and valve selection by the implanting surgeon cannot be excluded.

The hemodynamic performance of aortic valve substitutes depends on a number of cofactors, such as left ventricular systolic and diastolic function, the patient’s volume status, function of the mitral valve, blood pressure, heart rate, and so forth, which were not analyzed in this study.

For various reasons, not all patients were able to reach higher exercise levels. Therefore, the hemodynamic data that are available for comparison at 75 Watts are scarce (Figure 1).

The result of echocardiography may be influenced by the sonic conditions that differ from patient to patient and may therefore be biased.

	Conclusions

Top Abstract Introduction Materials and Methods Results Discussion Conclusions References

 
The 4 bioprostheses compared in this study showed satisfactory hemodynamic results at rest and during exercise in patients with a small aortic annulus. Completely supra-annular valves were designed to minimize the flow obstacle that is caused by the sewing ring and stent material reaching into the annulus diameter. We demonstrated that this concept does not necessarily lead to superior hemodynamic results, which we believe may depend on the anatomy of the aortic root. The pericardial, completely supra-annular Magna bioprosthesis with a reduced sewing ring indicated the lowest pressure gradients at rest and during exercise and seems to deal best with the challenge of achieving good hemodynamics in patients with a small aortic annulus, which is often associated with a narrow ascending aorta.

	Footnotes

 
¹ Walter Eichinger reports lecture fees from Edwards and St. Jude

² Ruediger Lange reports lecture fees from Edwards and Sorin.

	References

Top Abstract Introduction Materials and Methods Results Discussion Conclusions References

 

1. Christakis GT, Buth KJ, Goldman BS, et al. Inaccurate and misleading valve sizing: a proposed standard for valve size nomenclature. Ann Thorac Surg 1998;66:1198-1203.[Abstract/Free Full Text]
   
2. Botzenhardt F, Eichinger WB, Bleiziffer S, et al. Hemodynamic comparison of bioprostheses for complete supra-annular position in patients with small aortic annulus. J Am Coll Cardiol 2005;45:2054-2060.[Abstract/Free Full Text]
   
3. Eichinger WB, Botzenhardt F, Guenzinger R, et al. The effective orifice area/patient aortic annulus area ratio: a better way to compare different bioprostheses?. A prospective randomized comparison of the Mosaic and Perimount bioprostheses in the aortic position. J Heart Valve Dis. 2004;13:382-388discussion 388-9.[Medline]
   
4. Sievers HH. Prosthetic aortic valve replacement. J Thorac Cardiovasc Surg 2005;129:961-965.[Free Full Text]
   
5. Vitale N, Clark SC, Ramsden A, Hasan A, Hilton CJ, Holden MP. Clinical and hemodynamic evaluation of small Perimount aortic valves in patients aged 75 years or older. Ann Thorac Surg. 2003;75:35-39discussion 40.[Abstract/Free Full Text]
   
6. Eichinger W, Gunzinger R, Botzenhardt F, Simmerl D, Gansera B, Kemkes BM. The Mosaic bioprosthesis in the aortic position at five years. J Heart Valve Dis 2000;9:653-660.[Medline]
   
7. Eichinger WB, Botzenhardt F, Gunzinger R, et al. Left ventricular mass regression after aortic valve replacement with the mosaic bioprosthesis. J Heart Valve Dis. 2002;11:529-536discussion 536.[Medline]
   
8. Botzenhardt F, Gansera B, Kemkes BM. Mid-term hemodynamic and clinical results of the stented porcine Medtronic mosaic valve in aortic position. Thorac Cardiovasc Surg 2004;52:34-41.[Medline]
   
9. Seguin JR, Grandmougin D, Folliguet T, Warembourg H, Laborde F, Chaptal PA. Long-term results with the Sorin Pericarbon valve in the aortic position: a multicenter study. J Heart Valve Dis 1998;7:278-282.[Medline]
   
10. Rassi Jr A, Crawford MH, Richards KL, Miller JF. Differing mechanisms of exercise flow augmentation at the mitral and aortic valves. Circulation 1988;77:543-551.[Abstract/Free Full Text]
    
11. DuBois D, DuBois EF. A formula to estimate the approximate surface area if height and weight be known. Arch Intern Med 1916;17:863-871.
    
12. Blais C, Dumesnil JG, Baillot R, Simard S, Doyle D, Pibarot P. Impact of valve prosthesis-patient mismatch on short-term mortality after aortic valve replacement. Circulation 2003;108:983-988.[Abstract/Free Full Text]
    
13. Frater RW, Salomon NW, Rainer WG, Cosgrove 3rd DM, Wickham E. The Carpentier–Edwards pericardial aortic valve: intermediate results. Ann Thorac Surg 1992;53:764-771.[Abstract/Free Full Text]
    
14. Cosgrove DM, Lytle BW, Williams GW. Hemodynamic performance of the Carpentier–Edwards pericardial valve in the aortic position in vivo. Circulation 1985;72:II146-II152.[Medline]
    
15. Takakura H, Sasaki T, Hashimoto K, et al. Hemodynamic evaluation of 19-mm Carpentier–Edwards pericardial bioprosthesis in aortic position. Ann Thorac Surg 2001;71:609-613.[Abstract/Free Full Text]
    
16. Botzenhardt F, Gansera B, Gunzinger R, Kemkes BM. [Clinical and hemodynamic results of the mosaic bioprosthesis in aortic position] Z Kardiol 2003;92:407-414.[Medline]
    
17. Eichinger WB, Schutz A, Simmerl D, et al. The mosaic bioprosthesis in the aortic position: hemodynamic performance after 2 years. Ann Thorac Surg 1998;66:S126-S129.[Medline]
    
18. Rahimtoola SH. The problem of valve prosthesis-patient mismatch. Circulation 1978;58:20-24.[Abstract/Free Full Text]
    
19. Gerosa G, Tarzia V, Rizzoli G, Bottio T. Small aortic annulus: the hydrodynamic performances of 5 commercially available tissue valves. J Thorac Cardiovasc Surg 2006;131:1058-1064.[Abstract/Free Full Text]
    
20. Seitelberger R, Bialy J, Gottardi R, et al. Relation between size of prosthesis and valve gradient: comparison of two aortic bioprosthesis. Eur J Cardiothorac Surg 2004;25:358-363.[Abstract/Free Full Text]
    
21. Blackstone EH, Cosgrove DM, Jamieson WR, et al. Prosthesis size and long-term survival after aortic valve replacement. J Thorac Cardiovasc Surg 2003;126:783-796.[Abstract/Free Full Text]
    
22. Mohty-Echahidi D, Malouf JF, Girard SE, et al. Impact of prosthesis-patient mismatch on long-term survival in patients with small St Jude Medical mechanical prostheses in the aortic position. Circulation 2006;113:420-426.[Abstract/Free Full Text]
    
23. Walther T, Rastan A, Falk V, et al. Patient prosthesis mismatch affects short- and long-term outcomes after aortic valve replacement. Eur J Cardiothorac Surg 2006;30:15-19.[Free Full Text]
    
24. Rahimtoola SH. Perspective on valvular heart disease: an update. J Am Coll Cardiol 1989;14:1-23.[Medline]
    
25. Pibarot P, Dumesnil JG, Lemieux M, Cartier P, Metras J, Durand LG. Impact of prosthesis-patient mismatch on hemodynamic and symptomatic status, morbidity and mortality after aortic valve replacement with a bioprosthetic heart valve. J Heart Valve Dis 1998;7:211-218.[Medline]
    

This article has been cited by other articles:

				M. J. Dalmau, J. M. Gonzalez-Santos, J. A. Blazquez, J. A. Sastre, J. Lopez-Rodriguez, M. Bueno, M. Castano, and A. Arribas Hemodynamic performance of the Medtronic Mosaic and Perimount Magna aortic bioprostheses: five-year results of a prospectively randomized study Eur J Cardiothorac Surg, June 1, 2011; 39(6): 844 - 852. [Abstract] [Full Text] [PDF]

				Y. Sakamoto, M. Yoshitake, H. Naganuma, N. Kawada, K. Kinouchi, and K. Hashimoto Reconsideration of Patient-Prosthesis Mismatch Definition From the Valve Indexed Effective Orifice Area Ann. Thorac. Surg., June 1, 2010; 89(6): 1951 - 1955. [Abstract] [Full Text] [PDF]

				S. Bleiziffer, A. Ali, I. M. Hettich, D. Akdere, R. P. Laubender, D. Ruzicka, J. Boehm, R. Lange, and W. Eichinger Impact of the indexed effective orifice area on mid-term cardiac-related mortality after aortic valve replacement Heart, June 1, 2010; 96(11): 865 - 871. [Abstract] [Full Text] [PDF]

				H. A. Vohra, R. N. Whistance, M. Bolgeri, T. Velissaris, G. M. K. Tsang, C. W. Barlow, and S. K. Ohri Mid-term evaluation of Sorin Soprano bioprostheses in patients with a small aortic annulus <=20 mm Interact CardioVasc Thorac Surg, March 1, 2010; 10(3): 399 - 402. [Abstract] [Full Text] [PDF]

				D. J. Ruzicka, I. Hettich, A. Hutter, S. Bleiziffer, C. C. Badiu, R. Bauernschmitt, R. Lange, and W. B. Eichinger The Complete Supraannular Concept: In Vivo Hemodynamics of Bovine and Porcine Aortic Bioprostheses Circulation, September 15, 2009; 120(11_suppl_1): S139 - S145. [Abstract] [Full Text] [PDF]

				T. Bottio, V. Tarzia, G. Rizzoli, and G. Gerosa The changing spectrum of bioprostheses hydrodynamic performance: considerations on in-vitro tests Interact CardioVasc Thorac Surg, October 1, 2008; 7(5): 750 - 754. [Abstract] [Full Text] [PDF]

				R. Guenzinger, W. B. Eichinger, I. Hettich, S. Bleiziffer, D. Ruzicka, R. Bauernschmitt, and R. Lange A prospective randomized comparison of the Medtronic Advantage Supra and St Jude Medical Regent mechanical heart valves in the aortic position: is there an additional benefit of supra-annular valve positioning? J. Thorac. Cardiovasc. Surg., August 1, 2008; 136(2): 462 - 471. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Walter B. Eichinger Sabine Bleiziffer Ralf Guenzinger Robert Bauernschmitt Ruediger Lange Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wagner, I. M. Articles by Lange, R. Search for Related Content PubMed PubMed Citation Articles by Wagner, I. M. Articles by Lange, R.