Therapy for diastolic heart failure: On the road from myths to multicenter trials

The article by Dauterman et al (1) on congestive heart failure with preserved systolic function in a statewide sample of community hospitals in this issue of Journal of Cardiac Failure is a valuable contribution to the embarassingly scant literature on diastolic heart failure (DHF). It is well written and balanced and carefully enunciates all pertinent limitations. Of the 3 principal findings, 2 provide credible “real-life” confirmation of reports from smaller studies and from population-based studies. The third finding on lack of efficacy of angiotensin-converting enzyme inhibitors (ACEIs) is more controversial, because it is somewhat contrary to conventional wisdom. In a large, retrospective cohort study derived from a Medicare Professional ReviewOrganization project, Dauterman et al found that older patients hospitalized for heart failure frequently have a relatively preserved left ventricular ejection fraction, defined as an ejection fraction (EF) of >40%. Fifty-five percent of patients in their database met this criterion. The investigators seem apologetic regarding this high figure, but it is not likely an overestimate as they seem willing to concede. In fact, this is the exact figure recently reported by the population-based Cardiovascular Health Study for the prevalence of this disorder among elderly living in the community (2). A nearly identical figure was found in the population-based Framingham Heart Study (3). The lowest figure reported from a population-based study, 43% incidence, is also not that far from 55%. Two hospital-based single-center studies provide comparable data (4,5); In the larger study 54% of older hospitalized patients had EF > 40% (4). Thus, a striking uniformity has emerged from widely diverse databases to verify that a little more than half of older patients with heart failure have DHF. The EF cut-point used for the case definition can substantially affect prevalence and incidence estimates. The cut-point 0.40 in the Dauterman study was probably mandated by a primary purpose of the database: to evaluate appropriate use of ACEI therapy in hospitalized Medicare patients. EF cut-points as low as 0.35 and as high as 0.60 have been used in other studies. Certainly, the higher the cut-point, the higher the confidence that the case can be attributed to diastolic rather than systolic left ventricular dysfunction. The lower end of the normal EF range therefore seems the most appropriate cut-point and, under most conditions, is 0.50. The term “preserved systolic function” has been used to describe groups with EF as low as 0.35, but it is preferable to use the term “mixed heart failure” to describe cases with EF 0.40. This distinction allows cases with normal EF ( 0.50) to be presumptively termed DHF and those with EF 0.40 to be termed systolic heart failure (SHF). Although some patients in the latter group also have degrees of diastolic dysfunction, this has limited clinical relevance because they currently must be treated according to SHF treatment guidelines. Dauterman et al confirm that although mortality in DHF is usually lower than in SHF, it is still substantial. When all available studies are compared, the gap in mortality between DHF and SHF appears to narrow as age and proximity to hospitalization increase. For example, in the few studies that have focused on elderly, hospitalized patients, mortality was similar in DHF and SHF patients (5). A population-based report from Olmsted county, Minnesota, also showed similar findings (6). Dauterman et al confirm the universal finding that regardless of potentially lower mortality, morbidity in From the Section of Cardiology, Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, NC. Supported in part by National Institute on Aging grant RO1 AG18915 and AG12257. In memory of Madelynn M. Roll. Reprint requests: Dalane W. Kitzman, MD, Section of Cardiology, Wake Forest University School of Medicine, Medical Center Blvd, Winston-Salem, NC 27157-1045. Copyright © 2001 by Churchill Livingstone 1071-9164/01/0703-0003$35.00/0 doi:10.1054/jcaf.2001.27665 Journal of Cardiac Failure Vol. 7 No. 3 2001