Acute Ventricular Reduction with the Acorn Cardiac Support Device: Effect on Progressive Left Ventricular Dysfunction and Dilation in Dogs with Chronic Heart Failure

Background and Aim: Surgical resection of myocardium that acutely reduces left ventricular (LV) volume in patients with advanced heart failure (HF), the so‐called “Batista Operation,” remains controversial. We examined the effects of acute LV reduction with the Acorn Cardiac Support Device (CSD) in dogs with HF (LV ejection fraction < 30%). Methods: HF was produced in 15 dogs by intracoronary microembolization. In nine dogs, intravenous dobutamine was administered to reduce LV end‐diastolic dimension (LVEDD) by 10%‐25%. While on dobutamine infusion, the CSD, a preformed knitted polyester device, was surgically placed around the ventricles, anchored to the arteriovenous (AV) groove, and tailored anteriorly to fit snugly over the ventricles. Dogs were then weaned off dobutamine. Results: On average, the procedure reduced LVEDD by 7 ± 1 mm (range 5–12 mm). Of the nine dogs, two died before completion of the study and seven survived for the entire period. Six dogs did not undergo device placement and served as controls. All were followed for 3 months prior to sacrifice. In controls, LV end‐diastolic volume increased after 3 months (66 ± 5 mL vs 77 ± 6 mL; p = 0.007), while in CSD‐treated dogs (n = 7), it decreased (80 ± 5 mL vs 60 ± 3 mL; p = 0.002). In controls, LV ejection fraction (EF) decreased after 3 months (27 ± 1% vs 23 ± 1%; p = 0.001) but was unchanged in CSD‐treated dogs (25 ± 1% vs 26 ± 1%; p = 0.66). Compared to controls, CSD‐treated dogs showed improved LV diastolic dysfunction and chamber sphericity, decreased wall stress, and no functional mitral regurgitation (MR). Conclusion: In dogs with advanced HF, acute LV reduction with the Acorn CSD prevents progressive global LV dilatation and ameliorates functional MR.