Heart failure associated with preserved systolic function: A common and costly clinical entity

Congestive heart failure (CHF) represents an enormous and growing clinical and epidemiologic problem. By current estimates more than 5 million patients in the United States, or approximately 2% of the adult population, are thought to have CHF, and 400,000 new cases are diagnosed each year.(1-3) Heart failure is the primary discharge diagnosis in approximately 1,000,000 hospital admissions each year, of which more than 80% are in patients $5 years and older, making it the most. common cause of hospital admission in the Medicare population.(4) Over a 3- to 6-month period 20% to 50% of patients will be readmitted.(5) In 1991 the cost of these hospitalizations was $5.45 billion compared with $2.24 billion for all types of cancer and $3.2 billion for myocardial infarction.(6) The 2-year mortality rate in patients with newly diagnosed disease is 35%, and the 6-year mortality rate is 67% in women and 82% in men.(7) To most physicians the typical image of the patient with CHF is one of a dilated cardiomyopathy and low left ventricular ejection fraction (LVEF). This is certainly the case when one is considering the "end stage" or refractory patient, which is the focus of this supplement. Indeed, the first response to the findings of normal or preserved LVEF is to consider alternative diagnoses, occult valvular disease, or silent ischemia. As an example of this focus on systolic dysfunction, patients with normal or even mildly depressed LVEF are rarely considered for transplantation. Furthermore the large multicenter trials that have defined the management of CHF have excluded patients with LVEF >35% or 40% or, in the case of the V-HeFT study, lack of LV enlargement. This focus on systolic dysfunction has left many physicians confused and uncomfortable in treating the patient with CHF and preserved systolic function; it is also responsible for the dearth of data on how to treat them. In recent years, however, there has been a growing recognition of the magnitude and importance of this problem. Patients with CHF and preserved systolic function ale surprisingly common, representing 20% to 50% of all patients with the diagnosis of CHF.(8-10) Yet despite the frequency of this syndrome, we know relatively little regarding its morbidity and mortality, how to diagnose it in a clinically applicable manner, and how to manage and prevent it. This is indicated by the 22-page American College of Cardiology/American Heart Association practice guidelines for the evaluation and management of heart failure, which devote only one page to diastolic dysfunction.(9) Patients with heart failure in the absence of systolic dysfunction were specifically excluded from the Agency for Health Care Policy and Research guidelines, primarily because it was believed that available evidence was inadequate to make recommendations for management.(11) Therefore the goal of this article is to review the mechanisms, epidemiology, and therapy of CHF with preserved systolic function and to paint out the important contribution of this syndrome to the total morbidity rate and cost of heart failure.