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Objectives: Both partial and complete annuloplasty rings are used for mitral valve repair for patients with functional mitral regurgitation (FMR). We sought to determine if recurrence of mitral regurgitation (MR) is affected by the type of ring used., Methods: Five hundred forty-eight patients diagnosed with FMR underwent mitral valve repair with ring annuloplasty between 1998 and 2008 in our institution. Medical records were reviewed retrospectively for clinical and echocardiographic data to determine the presence of recurrent MR (defined as moderate or severe)., Results: Among 479 patients for whom postoperative echocardiographic data were available, recurrent MR occurred less frequently in the complete versus partial ring group (20 of 209 [10%] vs 56 of 270 [21%] patients; P = .001), despite lower preoperative ejection fractions in the complete ring group (median, 35%; interquartile range, 25%-45% vs median, 40%; interquartile range, 30%-55%; P < .001). Kaplan-Meier analysis demonstrated greater freedom from recurrent MR in the complete ring group (108 vs 103 months; P = .001). Risk-matched propensity analysis of 102 patients per group (area under the curve, 0.824; 95% confidence interval, 0.788-0.861; P < .001) also demonstrated that complete ring recipients had greater freedom from recurrent MR than partial ring recipients by univariate analysis (7 [7%] vs 17 [17%] patients; P = .049), and a trend toward greater freedom by Kaplan-Meier analysis (110 vs 104 months; P = .068)., Conclusions: The use of complete mitral annuloplasty rings provides improved freedom from recurrent MR in patients with FMR., (Copyright © 2013 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.)

Objective: In standard ventricular restraint therapy, a single level of restraint is applied to the entire ventricular surface. We showed previously that at high restraint levels, cardiac tamponade develops because of the thin-walled right ventricle, even while the left ventricle remains unaffected. We now hypothesize that applying restraint exclusively to the left ventricle permits higher levels of restraint, resulting in increased benefit to the left ventricle., Methods: The acute effect of restraint applied to the left ventricle alone was analyzed in healthy and cardiomyopathic sheep hearts. Restraint therapy was applied by fluid-filled epicardial balloons placed solely around the left ventricle. Restraint level was defined by the measured balloon luminal pressure at end diastole. At incrementally higher restraint levels (0, 3, 5, 8, 10, 12, and 14 mm Hg), transmural myocardial left ventricular pressure (P(tm) = Left ventricle pressure - Balloon pressure) and indices of myocardial oxygen consumption were measured in healthy sheep (n = 5) and in sheep with heart failure (n = 6)., Results: Increasing restraint from 0 to 14 mm Hg decreased transmural myocardial pressure by 48.8% (P ≤ .02) and the left ventricle tension-time index by 39.1% (P ≤ .01), and the pressure-volume area decreased by 58.4% (P ≤ .01). Similarly, stroke work decreased by 57.9% (P ≤ .03). Systemic hemodynamics were unchanged. There was no difference in the trend for all indices between animals that were healthy and those with heart failure., Conclusions: We showed previously that, with standard restraint, right ventricle tamponade develops at high restraint levels, limiting restraint therapy. We now show that restraint applied to the left ventricle alone permits increased restraint levels, without causing right ventricle or left ventricle tamponade, for greater therapeutic benefit. We conclude that partial left ventricle restraint may be more effective than standard restraint., (Copyright © 2013 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.)

Objective: The effects of ventricular restraint level on left ventricular reverse remodeling are not known. We hypothesized that restraint level affects the degree of reverse remodeling and that restraint applied in an adjustable manner is superior to standard, nonadjustable restraint., Methods: This study was performed in 2 parts using a model of chronic heart failure in the sheep. In part I, restraint was applied at control (0 mm Hg, n = 3), low (1.5 mm Hg, n = 3), and high (3.0 mm Hg, n = 3) levels with an adjustable and measurable ventricular restraint (AMVR) device. Restraint level was not altered throughout the 2-month treatment period. Serial restraint level measurements and transthoracic echocardiography were performed. In part II, restraint was applied with the AMVR device set at 3.0 mm Hg (n = 6) and adjusted periodically to maintain that level. This was compared with restraint applied in a standard, nonadjustable manner using a mesh wrap (n = 6). All subjects were followed up for 2 months with serial magnetic resonance imaging., Results: In part I, there was greater and earlier reverse remodeling in the high restraint group. In both groups, the rate of reverse remodeling peaked and then declined as the measured restraint level decreased with progression of reverse remodeling. In part II, adjustable restraint resulted in greater reverse remodeling than standard restraint. Left ventricular end diastolic volume decreased by 12.7% (P = .005) with adjustable restraint and by 5.7% (P = .032) with standard restraint. Left ventricular ejection fraction increased by 18.9% (P = .014) and 14.4% (P < .001) with adjustable and standard restraint, respectively., Conclusions: Restraint level affects the rate and degree of reverse remodeling and is an important determinant of therapy efficacy. Adjustable restraint is more effective than nonadjustable restraint in promoting reverse remodeling., (Copyright © 2013 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.)

Objective: Cellular and mechanical treatment to prevent heart failure each holds therapeutic promise but together have not been reported yet. The goal of the present study was to determine whether combining a cardiac support device with cell-based therapy could prevent adverse left ventricular remodeling, more than either therapy alone., Methods: The present study was completed in 2 parts. In the first part, mesenchymal stem cells were isolated from rodent femurs and seeded on a collagen-based scaffold. In the second part, myocardial infarction was induced in 60 rats. The 24 survivors were randomly assigned to 1 of 4 groups: control, stem cell therapy, cardiac support device, and a combination of stem cell therapy and cardiac support device. Left ventricular function was measured with biweekly echocardiography, followed by end-of-life histopathologic analysis at 6 weeks., Results: After myocardial infarction and treatment intervention, the ejection fraction remained preserved (74.9-80.2%) in the combination group at an early point (2 weeks) compared with the control group (66.2-82.8%). By 6 weeks, the combination therapy group had a significantly greater fractional area of change compared with the control group (69.2% ± 6.7% and 49.5% ± 6.1% respectively, P = .03). Also, at 6 weeks, the left ventricular wall thickness was greater in the combination group than in the stem cell therapy alone group (1.79 ± 0.11 and 1.33 ± 0.13, respectively, P = .02)., Conclusions: Combining a cardiac support device with stem cell therapy preserves left ventricular function after myocardial infarction, more than either therapy alone. Furthermore, stem cell delivery using a cardiac support device is a novel delivery approach for cell-based therapies., (Copyright © 2010 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.)

Objective: Effects of ventricular restraint on the left ventricle are well documented, but effects on the right ventricle are not. We hypothesized that restraint affects the right and left ventricles differently., Methods: We studied acute effects of restraint on left and right ventricular mechanics in healthy sheep (n = 14) with our previously described technique of adjustable and measurable restraint. Transmural pressure, myocardial oxygen consumption indices, diastolic compliance, and end-systolic elastance were assessed at 4 restraint levels for both ventricles. We then studied long-term effects of restraint for 4 months in an ovine model of ischemic dilated cardiomyopathy (n = 6). Heart failure was induced by coronary artery ligation, and polypropylene mesh was wrapped around the heart to simulate clinical restraint therapy. All subjects were followed up with serial cardiac magnetic resonance imaging to assess left and right ventricular volumes and function., Results: Restraint decreased left ventricular transmural pressure (P < .03) and myocardial oxygen consumption indices (P < .05) but not left ventricular diastolic compliance (P = .52). Restraint had no effect on right ventricular transmural pressure (P = .82) or myocardial oxygen consumption indices (P = .72) but reduced right ventricular diastolic compliance (P < .01). In long-term studies, restraint led to reverse left ventricular remodeling with decreased left ventricular end-diastolic volume (P < .006) but did not affect right ventricular end-diastolic volume (P = .82)., Conclusions: Ventricular restraint affects the left and right ventricles differently. Benefits of restraint for right ventricular function are unclear. The left ventricle can tolerate more restraint than the right ventricle. With current devices, the right ventricle may limit overall therapeutic efficacy., (Copyright 2010 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.)