Beneficial effects of the CorCap cardiac support device: five-year results from the Acorn Trial.

BACKGROUND: The CorCap cardiac support device (Acorn Cardiovascular, Inc, St Paul, Minn) is the first device that specifically addresses ventricular remodeling in heart failure by reducing wall stress. We previously reported outcomes from the Acorn randomized trial to a common closing date (22.9 months of follow-up). This report summarizes results of extended followup to 5 years. METHODS: A total of 107 patients were enrolled in the no-mitral valve repair/replacement stratum including 57 in the CorCap treatment group and 50 in the control (optimal medical therapy alone) group. Patients were assessed every year, until completing 5 years of follow-up, for survival, adverse events, major cardiac procedures, New York Heart Association (NYHA) functional status, and echocardiograms, which were read at a core laboratory. RESULTS: Overall survivals were similar between the treatment and control groups, demonstrating no late adverse effect on mortality. The treatment group had significant reductions in left ventricular end-diastolic volume (P = .029) as well as a small increase in sphericity index. More patients in the treatment group improved by at least 1 NYHA functional class (P = .0005). There was no difference in rates of adverse events. In a subgroup of patients with an intermediate left ventricular end-diastolic dimension, there was a significant reduction in the Kaplan-Meier estimate of the freedom from the composite end point of death and major cardiac procedures (P = .04). CONCLUSIONS: These cumulative data demonstrate the sustained reverse remodeling of the left ventricle and the long-term safety and efficacy of the CorCap cardiac support device as an adjunctive therapy for patients with heart failure who remain symptomatic despite optimal medical therapy.

Mitral valve repair in heart failure: five-year follow-up from the mitral valve replacement stratum of the Acorn randomized trial.

OBJECTIVE: The study objective was to evaluate the long-term (5-year) safety and efficacy of mitral valve surgery with and without the CorCap cardiac support device (Acorn Cardiovascular, St Paul, Minn) in patients with dilated cardiomyopathy and New York Heart Association class II-IV heart failure. BACKGROUND: The Acorn trial provided a unique opportunity to assess the long-term safety and efficacy of mitral valve surgery because clinical visits and echocardiograms (read by a core laboratory) were completed for 5 years of follow-up. Further, this study provided follow-up data on the long-term effect of the CorCap cardiac support device as an adjunct to mitral valve surgery. METHODS: From the original Acorn trial (n = 300 patients), 193 patients were enrolled in the mitral valve repair/replacement stratum. A total of 102 were randomized to mitral valve surgery alone (control group) and 91 were randomized to mitral valve surgery with implantation of the CorCap cardiac support device (treatment group). Patients were followed up for 5 years. RESULTS: As previously reported, 30-day operative mortality was only 1.6%. At 5 years, the total mortality was 30% with an average annual mortality rate of approximately 6% per year. The effects of mitral valve surgery led to a progressive decrease in left ventricular end-diastolic and end-systolic volumes, which were highly significant at all time points. At the end of 5 years, there was an average reduction in left ventricular end-diastolic volume of 75 mL, which represents a 28% reduction from baseline. During 5 years of follow-up, 29 patients had recurrent mitral regurgitation and 5 patients underwent repeat mitral valve surgery. The addition of the CorCap device led to greater decreases in left ventricular end-diastolic volume (average difference of 16.5 mL; P = .05), indicating that the CorCap device had an additive effect to the mitral valve operation. CONCLUSIONS: This study demonstrates long-term improvement in left ventricular structure and function after mitral valve surgery for up to 5 years. These data provide evidence supporting mitral valve repair in combination with the Acorn CorCap device for patients with nonischemic heart failure with severe left ventricular dysfunction who have been medically optimized yet remain symptomatic with significant mitral regurgitation.

Mechanisms of recurrent functional mitral regurgitation after mitral valve repair in nonischemic dilated cardiomyopathy: importance of distal anterior leaflet tethering.

BACKGROUND: Recurrent functional mitral regurgitation (MR) has been reported after mitral valve repair with annuloplasty in patients with dilated cardiomyopathy, but the mechanism is not understood completely. The authors sought to identify abnormalities of the mitral valve and left ventricle that are associated with recurrent MR after mitral annuloplasty. METHOD AND RESULTS: In 104 patients with idiopathic dilated cardiomyopathy who underwent annuloplasty for functional MR, basal mitral anterior leaflet angle, distal mitral anterior leaflet angle (ALAtip), posterior leaflet angle, coaptation depth, tenting area, mitral annular dimensions, left ventricular volumes, and MR severity were quantified by echocardiography before surgery and at 6-month intervals after it. Compared with patients without MR recurrence (n=79), patients with recurrent MR (defined as > or =2+) (n=25) had greater ALAtip (P<0.001) and basal mitral anterior leaflet angle (P<0.001), greater coaptation depth and tenting area (P<0.001), larger left ventricular volumes (P<0.001), and worse left ventricular ejection fraction (P<0.05) but similar mitral annular dimensions and postoperative exaggeration in posterior leaflet angle. Multivariable analysis identified postoperative ALAtip as the major determinant of postoperative MR. Receiver operator characteristic curves identified preoperative ALAtip as the best predictor of MR recurrence (area under curve, 0.98). For ALA(tip) >25 degrees, the sensitivity, specificity, and positive and negative predictive values in predicting recurrent MR were 88%, 94%, 82%, and 93%, respectively. Three distinct patterns of anterior leaflet tethering (minimal, basal, and distal) with an increasing risk of recurrent MR were identified. CONCLUSIONS: Posterior leaflet tethering is invariable after mitral annuloplasty, rendering postoperative mitral competence highly dependent on distal anterior leaflet mobility.

Clinical evaluation of the CorCap Cardiac Support Device in patients with dilated cardiomyopathy.

BACKGROUND: Left ventricular (LV) remodeling is related to adverse outcomes in heart failure. The CorCap Cardiac Support Device (CSD; Acorn Cardiovascular, Inc, St. Paul, MN) is an implantable device that attenuates LV remodeling. METHODS: The Acorn trial assessed the safety and efficacy of the CSD in 300 heart failure patients. Patients needing mitral surgery (n = 193) were randomized to mitral surgery alone or mitral surgery plus CSD. Patients who did not need mitral surgery (n = 107) were randomized to medical therapy or medical therapy plus CSD. The primary endpoint was a clinical composite based on changes in patient vital status, the need for major cardiac procedures for worsening heart failure, and a change in New York Heart Association (NYHA) class. RESULTS: The proportional odds ratio for the primary endpoint favored treatment with the CSD (1.73 confidence interval [CI]: 1.07 to 2.79; p = 0.024). The CSD-treated patients received significantly (p = 0.01) fewer cardiac procedures indicative of worsening heart failure and had an improvement in New York Heart Association class (p = 0.049). There was no significant difference in survival between groups (p = 0.85). Treatment with the CSD led to a decrease in LV end-diastolic (p = 0.009) and end-systolic volumes (p = 0.017), an increase in the LV sphericity index (p = 0.026), an improvement in the Minnesota Living with Heart Failure score (p = 0.04), and the Short Form-36 Questionnaire (p = 0.015). There was no evidence for a significant difference (p = 0.43) in serious adverse events between the treatment and control groups. CONCLUSIONS: The results of the Acorn trial support the hypothesis that preventing LV remodeling with a CSD favorably impacts the untoward natural history of heart failure.

Sustained benefits of the CorCap Cardiac Support Device on left ventricular remodeling: three year follow-up results from the Acorn clinical trial.

BACKGROUND: The objective of this study was to assess the long-term effects of the CorCap Cardiac Support Device (CSD; Acorn Cardiovascular, Inc, St. Paul, MN) on left ventricular (LV) structure and function in patients with heart failure. Cardiac support devices, which reduce LV wall stress, have been shown to promote reverse remodeling in three different experimental models of heart failure. However, long-term effects in patients with heart failure have not been reported. METHODS: We enrolled 300 patients with heart failure in the Acorn Randomized Trial, as previously reported (Ann Thorac Surg 2007;84:1226-35). Echocardiograms were obtained every six months until the last patient was followed for one year, and then annually thereafter. Standard measurements of LV volumes, ejection fraction, and sphericity index were made by a Core laboratory at the Mayo Clinic who were blinded to treatment assignment. RESULTS: Patients treated with the CorCap Cardiac Support Device had significant reductions in LV end diastolic volume (average difference 18.8 mL; p = 0.005) and LV end systolic volume (average difference 15.6 mL; p = 0.013) compared with the control group. Sphericity index was significantly increased in the treatment group (average difference 0.045 units; p = 0.018). These changes were maintained over three years of follow-up. The improvements in LV size and shape were observed when the CorCap was implanted concomitantly with mitral value surgery or by itself. CONCLUSIONS: These results demonstrate that the CorCap Cardiac Support Device has a long-term beneficial impact on LV size and shape in patients with heart failure.

Mitral valve surgery in heart failure: insights from the Acorn Clinical Trial.

OBJECTIVE: The study objective was to evaluate in a prospective, randomized, multicenter trial the safety and efficacy of mitral valve surgery with and without the CorCap cardiac support device (Acorn Cardiovascular, St Paul, Minn) in patients with New York Heart Association Class II to IV heart failure. BACKGROUND: Although mitral valve surgery has been performed successfully in patients with heart failure, the safety and long-term efficacy have not been established in a multicenter prospective trial. Cardiac support devices that reduce ventricular wall stress and promote beneficial reverse remodeling have been proposed as a new treatment option as a stand-alone procedure and as an adjunct to mitral valve surgery. METHODS: A subgroup of 193 patients were enrolled in the mitral valve repair or replacement stratum of the Acorn Clinical Trial; 102 patients were randomized to the mitral valve surgery alone group (control) and 91 patients were randomized to mitral valve surgery with implantation of the CorCap cardiac support device. Patients were followed for a median duration of 22.9 months. RESULTS: For the entire mitral valve surgery group, the 30-day operative mortality rate was only 1.6% at 30 days. Mitral surgery was associated with progressive reductions in left ventricle end-diastolic volume, left ventricle end-systolic volume, and left ventricular mass, and increases in left ventricle ejection fraction and sphericity index, all consistent with reverse remodeling. Recurrence of clinically significant mitral regurgitation was uncommon. Quality of life, exercise performance, and New York Heart Association functional class were all improved. Finally, the addition of the CorCap cardiac support device led to greater decreases in left ventricular end-diastolic volume and left ventricular end-systolic volume, a more elliptical shape, and a trend for a reduction in major cardiac procedures and improvement in quality of life compared with mitral surgery alone. CONCLUSIONS: These findings suggest that there is clear benefit to the surgical elimination of mitral regurgitation and that there is additional benefit with the CorCap cardiac support device. Given the improvement in left ventricle structure and function, along with a low mortality rate, physicians should strongly consider offering mitral valve surgery in combination with the CorCap cardiac support device to patients with heart failure who are on an optimal medical regimen.

One-year clinical experience with the Acorn CorCap cardiac support device: results of a limited market release safety study in Italy and Sweden.

BACKGROUND: The Acorn CorCap cardiac support device (CSD) is a mesh-like device intended to provide end-diastolic support and reduce ventricular wall stress. Animal studies with the CorCap CSD have demonstrated beneficial reverse remodeling, and preliminary safety studies in patients with heart failure have shown that the device is safe and associated with improved left ventricular (LV) structure and function. The objective of the current study was to further evaluate the safety and efficacy of the CorCap CSD in patients with advanced heart failure. METHODS: Twenty-four patients with dilated cardiomyopathy, severe LV dysfunction, and advanced heart failure (NYHA class II-IV) were enrolled at four centers in Italy and Sweden. All patients underwent CorCap CSD implantation either alone (n = 3) or in combination with mitral valve repair/replacement (n = 13), coronary artery bypass surgery (n = 6), combined mitral valve repair/coronary artery bypass surgery (n = 1) or aneurysmectomy (n = 1). RESULTS: The LV end-diastolic diameter decreased from 69.3 +/- 7.2 to 60.1 +/- 9.0 mm at 3 months, 60.9 +/- 9.6 mm at 6 months, and 58.9 +/- 8.0 mm at 12 months (all p < 0.05). A trend toward an improved LV ejection fraction (28.8 +/- 10.5% at baseline and 32.4 +/- 12.7, 33.1 +/- 10.8, and 33.8 +/- 13.9% at 3, 6 and 12 months respectively) was also noted. The NYHA functional class, 6-min walking distance, and quality of life as measured using Uniscale were all improved. There were no differences in response among the patients submitted to the different types of concomitant surgery. CONCLUSIONS: In agreement with earlier safety studies, even the present investigation demonstrated improvements in cardiac structure and function as well as in patient functional status after Cor Cap CSD implantation. Randomized controlled trials are in progress.

Rationale, design, and methods for a pivotal randomized clinical trial for the assessment of a cardiac support device in patients with New York health association class III-IV heart failure.

BACKGROUND: Heart failure remains a progressive disease with incremental morbidity and mortality despite optimal medical therapy. A growing body of evidence suggests that progressive left ventricular (LV) remodeling is directly related to a deterioration in LV performance and untoward clinical outcomes for heart failure patients. Preclinical and early phase I clinical studies with the CorCap Cardiac Support Device (CSD), a passive cardiac support device that prevents cardiac remodeling, have shown that it is safe and is associated with improvements in LV structure and function, as well as patient symptomatology. METHODS AND RESULTS: The Acorn Pivotal Trial is a pivotal prospective, randomized, evaluation of the CorCap CSD in patients with New York Heart Association class III-IV heart failure. Patients will be enrolled into one of two different strata. Patients who require a mitral valve repair/replacement (MVR) will fall into the "MVR stratum" and will be randomized to either treatment (MVR surgery plus the CSD) or control (MVR surgery alone). Patients who do not have a clinical indication for MVR surgery will fall into the "no-MVR stratum" and will also be randomized to either treatment (CSD implant plus optimal medical therapy) or control (optimal medical therapy alone). A total of 300 patients (150 treatment and 150 control) will be enrolled. The primary endpoint of the trial is the change in clinical status from baseline to the end of the efficacy phase (1 year), as determined by a clinical composite score. Patients will be classified as improved, worsened, or unchanged based upon patient vital status, the occurrence of a major cardiac procedure indicative of heart failure progression, and a change in the assessment of New York Heart Association functional class. CONCLUSIONS: The Acorn Pivotal Trial will formally test the hypothesis that preventing LV remodeling using a passive cardiac support device will favorably impact the untoward natural history of heart failure and thus represents an important departure from all previous medical and device studies that have been reported to date.