Abstract 11217: A New Treatment for Diastolic Heart Failure: Trabecular Cutting

Abstract

Background: Heart failure with preserved ejection fraction remains a leading cause of hospitalization, without development of new medications and operative procedures to treat these patients. We hypothesize that trabeculae carneae serve an important role in modulating LV diastolic compliance, and during hypertrophy of the myocardium, trabeculae contribute to abnormal compliance. Methods and Results: Eight ex vivo human hearts from patients with LV diastolic dysfunction were perfused at 37[[Unable to Display Character: ⁰]]C and had a balloon inserted into the LV through the mitral annulus. Diastolic LV pressure-volume compliance curves were measured at baseline and following trabecular cutting. LV compliance improved significantly (n=6, p<0.001), but not in the control hearts without trabecular cutting (n=2, p=0.85). The figure shows aggregate data from the six hearts before and after trabecular cutting. To determine if trabeculae serve a similar role in all mammals, 28 hearts from 10 species were obtained. We demonstrate significant relationships between circumferential wall stress and the number of trabeculae in these species, particularly trabeculae which attach nets of trabeculae to the ventricle walls (p=0.02, n=733) and trabeculae located at the apex and free wall (p=0.02, n=602). The percent of LV cardiac titin of the stiff isoform (%N2B), a determinate of LV diastolic compliance, also demonstrated a significant relationship with the number of trabeculae with the same anatomic subsets (p=0.04, n=597; and p=0.02, n=488, respectively). Conclusions: We demonstrate for the first time that rather than being an embryologic remnant, trabeculae carneae serve an important role in the maintenance of passive LV diastolic compliance, and can contribute to LV diastolic dysfunction. A new procedure, cutting trabeculae, is proposed to improve LV diastolic compliance.