Archives | Journal of Heart Valve Disease

Volume 19 Issue 1

None 2013

Research Article Open Access

Mitral valve mechanics following posterior leaflet patch augmentation

Azadeh Rahmani, Ann Q Rasmussen, Jesper L Honge, Bjorn Ostli, Robert A Levine, Albert Hagège, Hans Nygaard, Sten L Nielsen, Morten O Jensen

Pages 1 - 17

Abstract

Background and aim of the study

Attention towards the optimization of mitral valve repair methods is increasing. Patch augmentation is one strategy used to treat functional ischemic mitral regurgitation (FIMR). The study aim was to investigate the force balance changes in specific chordae tendineae emanating from the posterior papillary muscle in a FIMR-simulated valve, following posterior leaflet patch augmentation.

Methods

Mitral valves were obtained from 12 pigs (body weight 80 kg). An in vitro test set-up simulating the left ventricle was used to hold the valves. The left ventricular pressure was regulated with water to simulate different static pressures during valve closure. A standardized oval pericardial patch (17 × 29 mm) was introduced into the posterior leaflet from mid P2 to the end of the P3 scallop. Dedicated miniature transducers were used to record the forces exerted on the chordae tendineae. Data were acquired before and after 12 mm posterior and 5 mm apical posterior papillary muscle displacement to simulate the effect from one of the main contributors of FIMR, before and after patch augmentation.

Results

The effect of displacing the posterior papillary muscle induced tethering on the intermediate chordae tendineae to the posterior leaflet, and resulted in a 39.8% force increase (p = 0.014). Posterior leaflet patch augmentation of the FIMR valve induced a 31.1% force decrease (p = 0.007). There was no difference in force between the healthy and the repaired valve simulations (p = 0.773).

Conclusion

Posterior leaflet patch augmentation significantly reduced the forces exerted on the intermediate chordae tendineae from the posterior papillary muscle following FIMR simulation. As changes in chordal tension lead to a redistribution of the total stress exerted on the valve, patch augmentation may have an adverse long-term influence on mitral valve function and remodeling.

Research Article Open Access

Comparison of Transesophageal Echocardiographic Analysis and Circulating Biomarker Expression Profile in Calcific Aortic Valve Disease

Rachana Sainger ,

Juan B. Grau ,

Emanuela Branchetti ,

Paolo Poggio ,

Eric Lai ,

Erblina Koka ,

William J. Vernick ,

Robert C. Gorman ,

Joseph E. Bavaria ,

Giovanni Ferrari

Pages 1 - 16

Abstract

Background and aim of the study

Aortic valve sclerosis (AVSc), the early asymptomatic stage of calcific aortic valve disease (CAVD), is characterized by a progressive thickening of the aortic cusps without obstruction of the left ventricular outflow. In spite of its high prevalence, there are no molecular markers to characterize the early stages of CAVD before it progresses to a severe, symptomatic stage of aortic valve stenosis (AVS). The study aim was to identify any correlation between circulating biomarkers and transesophageal echocardiography (TEE) evaluation.

Methods

A total of 330 patients with various degrees of CAVD was enrolled into the study. Blood was collected from each patient prior to surgery, and analyzed using ELISA kits following the manufacturers' instructions.

Results

Significantly higher plasma osteopontin (OPN) levels were observed in AVSc patients (72.7 ± 1.8 ng/ml; p <0.001) and AVS patients (64.3 ± 5.1 ng/ml; p <0.001) when compared to controls (30.3 ± 1.8 ng/ml). Parathyroid hormone (PTH) levels in AVSc and AVS patients (164.1 ± 16.5 and 134.3 ± 14.6 pg/ml; p <0.001 and p = 0.04, respectively) were also significantly higher than in controls (61.8 ± 4.92 pg/ml). Upon further analysis, plasma levels of OPN (p <0.001) and PTH (p <0.001) were found to be significantly higher in asymptomatic AVSc patients, even before calcium deposition was detected on TEE evaluation. Fetuin-A levels were lower at all stages of CAVD when compared to controls (p <0.001 and p ≤0.05, respectively), but were comparable among the patient groups. NT-levels were significantly higher in AVS patients than in controls (p ≤0.01).

Conclusion

Serum levels of OPN, PTH, and fetuin-A showed a significant association with different stages of CAVD, with variations in their levels occurring before calcium nodules are visualized during TEE evaluation. The study results may help not only to provide a better understanding of the progression of CAVD but also to develop new tools that can be used to stage these patients.

Research Article Open Access

Impact of rheumatic mitral stenosis on aortic elastic properties

Suleyman Ercan, Gokhan Altunbas, Vedat Davutoglu, Fethi Yavuz, Okkeş Uku, Fuat Basanalan, Mehmet Kaplan, Hayri Alici

Pages 1 - 10

Abstract

Background and aim of the study: Although mitral stenosis has profound effects on the circulation and hemodynamics, few data exist regarding its impact on aortic elastic properties. The study aim was to determine the association between mitral stenosis and aortic elastic properties by using strain and distensibility as a surrogate.

Methods: Sixty-six patients with echocardiographic documentation of rheumatic mitral stenosis, and 25 age- and gender-matched healthy control subjects were enrolled in the study. Aortic elasticity parameters including strain and distensibility were measured by means of echocardiography.

Results: The mean age of the patient and control groups were 41.8 +/- 12.0 and 38.9 +/- 5.0 years, respectively (p = 0.12). There was a significant impairment in distensibility and strain in the patient group compared to controls (0.276 +/- 0.167 versus 0.491 +/- 0.260 cm2 x dyn(-1), p = 0.001; 6.54 +/- 3.18% versus 9.19 +/- 4.78%, p = 0.015). There was a strong correlation between distensibility and left atrial diameter (p < 0.001; r = -0.39), left atrial volume index (p < 0.001; r = -0.56), mitral valve area (p < 0.001; r = 0.40), and mean transmitral gradient (p = 0.022; r = -0.18). Strain was also associated with left atrial diameter (p = 0.002; r = -0.32), left atrial volume index (p < 0.001; r = -0.41), mitral valve area (p = 0.002; r = 0.31), and mean transmitral gradient (p = 0.035; r = -0.18).

Conclusion: Mitral stenosis was shown to be associated with impaired aortic elasticity, but further studies are required to clarify the clinical significance of this finding.

Research Article Open Access

Risk-adjusted survival after tissue versus mechanical aortic valve replacement: a 23-year assessment

Jeffrey G. Gaca

Pages 1 - 13

Abstract

Background and aim of the study

Detailed analyses of risk-adjusted outcomes after mitral valve surgery have documented significant survival decrements with tissue valves at any age. Several recent studies of prosthetic aortic valve replacement (AVR) also have suggested a poorer performance of tissue valves, although analyses have been limited to small matched series. The study aim was to test the hypothesis that AVR with tissue valves is associated with a lower risk-adjusted survival, as compared to mechanical valves.

Methods

Between 1986 and 2009, primary isolated AVR, with or without coronary artery bypass grafting (CABG), was performed with currently available valve types in 2,148 patients (1,108 tissue valves, 1,040 mechanical). Patients were selected for tissue valves to be used primarily in the elderly. Baseline and operative characteristics were documented prospectively with a consistent variable set over the entire 23-year period. Follow up was obtained with mailed questionnaires, supplemented by National Death Index searches. The average time to death or follow up was seven years, and follow up for survival was 96.2% complete. Risk-adjusted survival characteristics for the two groups were evaluated using a Cox proportional hazards model with stepwise selection of candidate variables.

Results

Differences in baseline characteristics between groups were (tissue versus mechanical): median age 73 versus 61 years; non-elective surgery 32% versus 28%; CABG 45% versus 35%; median ejection fraction 55% versus 55%; renal failure 6% versus 1%; diabetes 18% versus 7% (p<0.01). Unadjusted Kaplan-Meier survival was significantly lower with tissue than mechanical valves; however, after risk adjustment for the adverse profiles of tissue valve patients, no significant difference was observed in survival after tissue or mechanical AVR. Thus, the hypothesis did not hold, and risk-adjusted survival was equivalent, of course qualified by the fact that selection bias was evident.

Conclusion

With selection criteria that employed tissue AVR more frequently in elderly patients, tissue and mechanical valves achieved similar survival characteristics across the spectrum of patient risk. Further studies of the relative outcomes of mechanical versus tissue valves across the spectrum of patient age seem indicated.

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Background and aim of the study

Methods

Results

Conclusion

Background and aim of the study

Methods

Results

Conclusion

Background and aim of the study

Methods

Results

Conclusion