Medtronic Mosaic porcine bioprosthesis: Satisfactory early clinical performance

doi:10.1016/S0003-4975(98)01128-X

The Annals of Thoracic Surgery

Volume 66, Issue 6, Supplement 1, December 1998, Pages S122-S125

Presented at the VII International Symposium on Cardiac Bioprostheses, Barcelona, Spain, June 13–15, 1997.

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Abstract

Background. The Medtronic (Minneapolis, MN) Mosaic porcine bioprosthesis is an investigational prosthesis which incorporates zero-pressure fixation, aortic root predilation, low profile stent, and alpha oleic acid antimineralization treatment.

Methods. From September 1994 to August 1996, 289 patients (mean age 70 years, range, 28 to 88 years) had 227 (78.5%) aortic valve replacements and 62 (21.5%) mitral valve replacements. Concomitant procedures were performed in 61.2% (139) of aortic valve replacements and 54.8% (34) of mitral valve replacements. Of the aortic valve replacement group 70 (30.8%) were in the 61 to 70 age group and 134 (59.0%) were 71 years or older. Of the mitral valve replacements, 23 (37.1%) were 61 to 70 years and 30 (48.4%) 71 years or older.

Results. The early mortality, overall, was 4.2% (12 of 289); for aortic valve replacement it was 4.0% (9) and for mitral valve replacement it was 4.8% (3). The late mortality for aortic valve replacement was 2.6% per patient-year (3 events, 1.3% of total) and for mitral valve replacement it was 3.3% per patient-year (one event, 1.6% of total). The reoperative rate for aortic valve replacement was 3.0% per patient-year (4), while there were no mitral valve replacement reoperations. The freedom from major thromboembolism was 97.3% ± 1.6% for aortic valve replacement and 94.7% ± 3.0% for mitral valve replacement at 1 to 1.5 years. The freedom from reoperation was 96.7% ± 1.7% for aortic valve replacement; there was no reoperation for mitral valve replacement. There were no cases of structural valve deterioration. In the aortic position the mean systolic gradient was low, approximately 11 mm Hg, across all sizes (range 8 to 12 mm Hg at 3 months and 10 to 13 mm Hg at 12 months). In the mitral position the mean diastolic gradient was approximately 5 mm Hg (range, 2 to 6 mm Hg) for all sizes 25 to 31 mm at the early and 1 year follow-up echocardiographic assessment.

Conclusions. The early clinical performance and in vivo hemodynamics are encouraging.

Section snippets

Patients and methods

The Medtronic Mosaic porcine bioprosthesis was implanted in 289 patients (289 procedures) from September 1994 to August 1996. There were 96 (33.2%) women and 193 (66.8%) men. The mean age was 70 years (range, 28 to 88 years). There were 227 (78.5%) aortic valve replacements (AVR) and 62 (21.5%) mitral valve replacements (MVR). Concomitant procedures were performed in 61.2% (139) of AVR; of these 111 were coronary artery bypasses (CAB). Concomitant procedures were performed in 54.8% (34) of MVR,

Results

The early overall mortality was 4.2% (12 of 289); for AVR it was 4.0% (9) and for MVR it was 4.8% (3). Of the nine AVR deaths, six had concomitant procedures (five CAB), and of the three MVR deaths, two had undergone CAB. There were no valve-related deaths. The late mortality for AVR was 2.3% per patient-year (three events, 1.3% of total) and for MVR, 2.9% per patient-year (one event, 1.6% of total).

The valve-related complications are detailed in Table 1. There were four patients in the AVR

Comment

The Mosaic prosthesis has the tissue preserved with glutaraldehyde at zero pressure, attained by aortic root distention with zero pressure at the leaflets. The first-generation and second-generation porcine bioprostheses have the tissue fixed with glutaraldehyde at zero, low, or high pressure but all without predilation of the aortic root.

Several investigators have studied the pathogenesis of structural valve deterioration 1, 2, 3, 4, 5. Valves fixed at high pressure have permanently altered

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Cited by (34)

Is patient-prosthesis mismatch a predictor of survival or a surrogate marker of co-morbidities in cardiac surgery?
2015, International Journal of Cardiology
Citation Excerpt :
The prostheses used were the following: St Jude Std, St Jude HP, Sorin Bicarbon, Medtronic Hall, Carbomedics, Medtronic Advantage, Medtronic Hanckock II, ATS, Mosaic, Perimount, Biocor, Toronto SPV, Freestyle, St Jude Epic, and Carpentier Edwards. The projected indexed EOA was derived from the published normal in vivo EOA values for each model and size of prosthesis implanted as previously described and validated [10–17]. EOA was averaged in case of more than one published value.
Patient–prosthesis mismatch (PPM) has ignited much debate and no definite conclusions have been drawn on the outcome of these patients. Therefore, additional large studies with long-term follow-up are required to help the cardiologist and surgeon outline the best therapeutic strategy for patients with high risk for PPM.
Patients who underwent aortic valve replacement (AVR) from 2000 to 2013 were identified. Baseline and operative data was extracted and indexed effective orifice area calculated for each patient. The presence of PPM was defined in those patients with an iEOA ≤ 0.85 cm²/m². Regression analyses were performed to determine the association of PPM with operative mortality, post-operative complications and survival. Predictors for PPM were evaluated based on clinical and operative data.
From 2023 patients who underwent AVR, PPM was present in 64.6%. These patients had increased age, more coronary artery bypass procedures, increased risk of diabetes, hypertension, higher creatinine values and higher Euroscore. Age, body surface area, prosthesis type and size were found to be predictors of mismatch. Operative mortality (8.1% vs 5.7%, p = 0.05), stroke (3.9% vs 2.4, p = 0.02) and acute kidney injury (47.6% vs 35.1%, p = < 0.001) were more frequent in patients with PPM and mean 10-year survival was reduced (6.6 years, 95% CI: 6.3–6.8 vs 7.3, 95% CI: 6.9–7.2, p < 0.001). After adjusting for confounders, PPM was not found to be associated to either adverse outcome or survival.
Patients with PPM have worse operative mortality, post-operative complications and survival mainly due to the fact that they represent a higher risk population based on age and co-morbidities.
Long-term results of the Medtronic Mosaic porcine bioprosthesis in the aortic position
2014, Journal of Thoracic and Cardiovascular Surgery
We addressed the long-term results of the Medtronic Mosaic porcine prosthesis in the aortic position.
From 1994 to 2004, 1007 Mosaic valves were used for aortic valve replacement. The data were prospectively collected, retrospectively analyzed, and stratified according to patient age at surgery (group 1, <70 years; group 2, 70-75 years; group 3, 76-80 years; and group 4, >80 years), using both actual (cumulative risks) and actuarial methods.
Operative mortality was 5% (valve related in 14%). Globally, 8122.17 patient-years were available (average follow-up, 8.5 ± 3.9 years; 99.8% complete). Overall, survival at 15 years was lower among the elderly strata (P < .0001). Freedom from structural valve deterioration (SVD) was 95.1% (actual) and 86.3% (actuarial; 24 SVD events). Survival free from SVD was lower in group 1 (P = .003) but comparable among the other groups. Overall freedom at 15 years from the composite endpoint (any valve-related adverse events) was 82% (actual) and 71.3% (actuarial). No meaningful intergroup differences were found in survival free from the composite endpoint (P = .9) or freedom from valve-related mortality (P = .8). Younger patients at surgery did not show accelerated degeneration. No relationship could be established between prosthetic size and SVD.
The implantation of a bioprosthesis in patients aged 70 years or older remains fully justified. The rate of SVD was higher in younger patients, mainly owing to their greater life expectancy. Patients younger than 70 can receive a bioprosthesis, provided that the correct information regarding the expected durability has been provided. This might be better accomplished through the actual methodology.
Con: Patient-prosthesis mismatch now is not an important consideration in the majority of patients after aortic valve replacement
2014, Journal of Cardiothoracic and Vascular Anesthesia
Comprehensive Echocardiographic Assessment of Normal Mitral Medtronic Hancock II, Medtronic Mosaic, and Carpentier-Edwards Perimount Bioprostheses Early after Implantation
2010, Journal of the American Society of Echocardiography
Citation Excerpt :
For MM valves, the EOA by the continuity equation ranged from 1.9 to 2.3 cm2 in 1 study13 and from 1.8 to 2.5 cm2 in a second study.14 Two other studies had findings that indicated the MM EOA ranged from 1.4 to 2.2 cm2 and from 1.4 to 2.6 cm2 for the various valve sizes, but the method for calculating the EOA was not described.15,16 Last, in 1 study, the IEOA calculated using the continuity equation ranged from 0.8 to 1.0 cm2/m2.17
Normal Doppler-derived hemodynamic data for mitral valve bioprostheses are limited.
To establish parameters for identifying normal function for each of the 3 types of bioprostheses examined, we conducted a comprehensive, retrospective, two-dimensional, and Doppler echocardiographic assessment of 179 patients who underwent implantation of the Medtronic Hancock II or the Medtronic Mosaic (Medtronic, Inc, Minneapolis, MN) porcine mitral valve bioprosthesis or the Carpentier-Edwards Perimount (Edwards Lifesciences LLC, Irvine, CA) bovine pericardial mitral valve bioprosthesis.
All bioprostheses were normal by clinical examination, intraoperative transesophageal echocardiography, and postoperative transthoracic echocardiography. Regardless of valve type and body surface area, the pressure half-time was < 124 ms in all patients. Mean gradient < 9.5 mm Hg, mitral E velocity < 2.6 m/s, mitral valve prosthesis time-velocity integral < 69 cm, and ratio of the mitral valve prosthesis time-velocity integral to the left ventricular outflow tract time-velocity integral < 3.4 were recorded in nearly all patients.
These cutoff values (mean + 2 standard deviation) are specific, but not sensitive, for identifying mitral valve prosthesis dysfunction. Prostheses with hemodynamic values that are higher than these cutoff values are likely dysfunctional, but in select cases, mitral valve prosthesis dysfunction may be present even when hemodynamic values are lower than these thresholds.
Impact of valve prosthesis-patient mismatch estimated by echocardiographic-determined effective orifice area on long-term outcome after aortic valve replacement
2008, American Heart Journal
The impact of valve prosthesis-patient mismatch on long-term outcome after aortic valve replacement estimated by various variables such as projected indexed effective orifice area and internal geometric orifice area obtained from in vivo or in vitro published data is still controversial.
The effective orifice area was measured by echocardiography in 533 patients. The mean age of the patients was 71 ± 9 years; mean follow-up time was 4.7 ± 2.2 years. The impact of severe (indexed effective orifice area ≤0.6 cm²/m²) and moderate mismatch (0.6 cm²/m² < indexed effective orifice area ≤0.85 cm²/m²) on survival was evaluated by Cox regression.
Severe mismatch (hazard ratio: 1.9 [1.08-3.21]) was a significant predictor of survival time after adjustment for age, left ventricular ejection fraction, atrial fibrillation, New York Heart Association class, serum creatinine, and hemoglobin level. The 5- and 7-year survival rates were 71% ± 4% and 54% ± 8% for patients with severe mismatch and 83% ± 4% and 80% ± 8% for patients with mild mismatch, respectively. The correlation between projected and measured indexed effective orifice area was of medium strength (r = 0.49), and the frequency of observed mismatch depended linearly on the projected indexed effective orifice area. Although projected indexed effective orifice area and indexed internal geometric orifice area were significant predictors of severe mismatch, the sensitivity and specificity for severe prosthesis-patient mismatch were only 75% and 52%, using an optimal threshold of projected indexed effective orifice area defined by the Youden index.
Severe prosthesis-patient mismatch estimated by effective orifice area measured within 10 days was an independent risk factor of survival time. Projected indexed effective orifice area determined at surgery does not sufficiently predict mismatch.
Rapid Bioprosthetic Valve Degeneration Resulting in Severe Mitral Stenosis
2008, Journal of the American Society of Echocardiography
A 61-year-old man presented 9 months after bioprosthetic mitral valve implantation with progressive exertional dyspnea. Transesophageal echocardiography revealed severe mitral stenosis with diffuse leaflet thickening but no calcification. Subsequent pathologic examination of the valve demonstrated infiltrating fibroconnective tissue and chronic inflammation. Careful echocardiographic follow-up of this valve type may be warranted, especially in patients with early recurrent symptoms.

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Original ArticlesMedtronic Mosaic porcine bioprosthesis: Satisfactory early clinical performance

Abstract

Section snippets

Patients and methods

Results

Comment

J Thorac Cardiovasc Surg

J Thorac Cardiovasc Surg

Cardiovasc Pathol

Ann Thorac Surg

Original Articles
Medtronic Mosaic porcine bioprosthesis: Satisfactory early clinical performance