Mitral valve surgery in heart failure: Insights from the Acorn clinical trial

C doi:10.1016/j.jtcvs.2006.05.013 n this issue of the Journal, Acker and colleagues present some of the outcomes of the CorCap study—specifically, the subgroup analysis of patients who underwent concomitant mitral valve surgery. In this randomized study, the ddition of the CorCap device provided enhanced geometric changes in the left entricular (LV) shape without having a significant additive effect on clinical utcomes. The most notable information contained in this dataset is the outcomes of the ontrol group: mitral valve surgery in medically optimized patients with significant unctional mitral regurgitation, myopathic hearts, and symptomatic congestive heart ailure. This subgroup represents an uncontrolled prospective analysis of isolated itral valve surgery in patients with significant functional mitral insufficiency, New ork Heart Association class III or IV, ejection fraction less than 35% (mean jection fraction, 23% 9%), and a dilated LV (mean LV end-diastolic volume, 70.1 100.3 mL). This group had an outstanding 1.6% 30-day mortality rate and ignificant improvements in quality of life, exercise performance, and New York eart Association functional class. Equally as important, mitral valve operations led o improvements in LV volumes, mass, and shape, all consistent with reverse emodeling. Finally, unlike other reports in the literature, the operations were urable, because recurrence of clinically significant MR was uncommon in this atient cohort. As a result, the authors conclude that the improvement in LV tructure and clinical function, along with a very low mortality rate, justifies strong onsideration for offering MV surgery to heart failure patients who are on an ptimal medical regimen. These are excellent results, and from the perspective of the CorCap, it would be ard to measure any additional clinical benefit from the CorCap device that would dvocate its addition to mitral valve surgery. The outcomes do, however, support the ypothesis that patients with cardiomyopathy benefit from the surgical correction of he functional mitral insufficiency. The results of this study add to a growing xperience of clinical improvement with mitral valve repair. Unfortunately, there till is considerable skepticism about the safety and efficacy of mitral valve surgery n patients with heart failure. Earlier this year, the American College of Cardiology ublished a continuing medical education course entitled “Mitral Valve Surgery for HF: A Failed Concept?” which taught that “surgical treatment of FMR results in ittle if any survival benefit or reverse remodeling” and “it is possible that MVR for MR reduces symptoms and improves exercise tolerance but conclusive data to upport this hypothesis do not exist.” The course went on to conclude that “the vailable data suggest that the current enthusiasm for surgical treatment of FMR hould be reconsidered until the results of a prospective trial confirms its efficacy.” ast year, another study, although nonrandomized and retrospective, failed to show survival benefit in a similar patient cohort. As recently as 1998, American Heart ssociation/American College of Cardiology guidelines even questioned the approriateness of surgical therapy in these patients. “Determining the surgical candidacy f the symptomatic patient with MR and far-advanced LV dysfunction is a common linical dilemma. If mitral valve repair appears likely, surgery should still be ontemplated, provided ejection fraction is 30%.” Last year, this approach was till considered “under development” by American Heart Association/American ollege of Cardiology guidelines for the treatment of heart failure.