Gender and Congestive Heart Failure
Heart failure (HF) is an increasing problem in the older adult population, specifically among women. The majority of health care expenses are generated in the last few years of life, and hospitalization for HF is one of the major medical conditions influencing the expenditure. The nature of women’s HF differs from men: coronary artery disease is the most common etiologic factor for HF in men while women more often suffer from hypertensive heart disease, which results in stiffness of the left ventricle with relaxation problems, and diastolic HF. Most commonly there is a long history of poorly controlled hypertension. In acute situations these patients often present with florid edema and congestion along with significantly elevated blood pressure levels, which are both challenging to treat. This short review covers issues related to gender differences in etiology and epidemiology of HF, and evaluates current evidence for drug therapies.
Key words: epidemiology, heart failure, gender, myocardial infarction, hypertension.
Introduction
Despite improvement of treatment options and understanding of the pathophysiology of heart failure (HF) the prevalence is still increasing. Estimates of the prevalence of symptomatic HF in the general European population range from 0.4% to 2%.1 Based on the recent U.S. statistics,2 the prevalence of HF among older women (>75 years) reached 10.9% and in men of the same age prevalence is 9.8%. Hospitalization for HF occurs more commonly in women. There were about one million hospital discharges due to HF in 2003 in the U.S., and women represented almost 60% of the patient population. In the U.S. the cost of HF in 2006 is estimated to reach almost 30 billion dollars. Guidelines for the treatment of HF are continuously updated as results from new clinical trials are incorporated into the dynamic process. Two important guidelines for diagnosis and treatment of HF were published in 2001: one by the ESC (European Society of Cardiology)3 and a joint set of recommendations by the ACC/AHA (American College of Cardiology/American Heart Association), which was updated 2005.4
However, as with most guidelines, there are gaps between them and clinical practice. There are also gaps between guidelines and trial results published after the guidelines’ publication. This article emphasizes the findings of the treatment gaps, and also evaluates the latest research results in HF treatment through a gender perspective.
Practice guideline recommendations for HF are summarized in Table 1.
Epidemiology and Etiology
HF is a growing problem among women, partially due to the rising number of older persons, more of whom are female. Based on recently published data from the Framingham Heart Study, subjects at age 40 (independent of gender) without HF had a one in five lifetime risk for developing congestive HF.6 In the same study, at the age of 40, the lifetime risk of HF without myocardial infarction was 1 in 9 in men and 1 in 6 for women. This difference is attributed to hypertension being the most common etiology for HF in women, whereas myocardial infarction is the most common factor causing HF in men.6 Unfortunately, hypertension--specifically systolic hypertension--is a very common problem in the older population, with prevalence reaching 83.4% in women aged 75 years and older and 69.2% in men 75 years and older. Hypertension is a treatable risk factor of congestive HF. Hypertension is adequately controlled in only 17.3% to 29.8% of U.S. adults. Even more concerning is that target blood pressure is achieved in only 17.6% of young adults