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

Abstract

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.

Figure 1

Kaplan – Meier mortality curve for the No-MVR Stratum over 5 years of follow up. Patients in the treatment group are in the solid line and patients in the control group are in the dotted line. The mortality curves between the treatment and control groups were similar, demonstrating the lack of any late adverse effect on mortality.

Figure 2

Longitudinal regression analysis for changes in LV end diastolic volume (LVEDV) in the No-MVR Stratum. The control group did not demonstrate any consistent changes in LVEDV over 5 years. In contrast, the CSD treatment group showed a progressive decrease in LVEDV that was persistent over 5 years. When averaged over 5 years, the treatment group LVEDV was smaller by 28.9 ml compared to the control group (p = 0.029)

Figure 3

Longitudinal regression analysis for changes in LV sphericity index in the No-MVR Stratum. The treatment group had a much larger increase in sphericity index, indicating a change to a more ellipsoidal shape. The average 5 year treatment – control difference was 0.038 units which was not statistically significant.

Figure 4

Longitudinal regression analysis for the percentage of patients with an improvement in ≥ 1 NYHA Functional class over 5 years of follow up in the No-MVR Stratum. At each time point, there were more patients in the treatment group who improved by at least one NYHA functional class. When averaged over 5 years, this difference was highly significant.

Figure 5

Kaplan – Meier estimate for the composite of death and major cardiac procedure for the focused cohort of the No-MVR Stratum. There was a large separation between the groups that was maintained through 5 years of follow up. The treatment group had fewer deaths, heart transplants, LVADS and bi-ventricular pacemakers.