The Olmsted Community Project - Olmsted Community Project

Description:

The Olmsted Community Project was a study of the classification and prognosis of all incident cases of congestive heart failure in Olmsted County, Minnesota, diagnosed in 1991.

Hypothesis:

To assess the clinical characteristics and natural history of CHF as it presents in the community, which the authors believed to differ from that seen in patients enrolled in clinical trials.

Study Design

Study Design:

Patients Enrolled: 216
NYHA Class: NYHA Class III or IV = 54%
Mean Follow Up: 5 years
Mean Patient Age: 99 years
Female: 42
Mean Ejection Fraction: Ejection fraction was assessed by echocardiography within 3 weeks before or after CHF diagnosis in 63% of patients. Ejection fraction <50% was present in 57% of these patients.

Patient Populations:

A new diagnosis of CHF according to the Framingham criteria during the period January 1,1991, through December 31,1991. Residency in Olmsted County 1 year before the diagnosis of CHF.

Primary Endpoints:

(1) the age distribution of patients with CHF in the community; (2) the prevalence of normal systolic function in patients with CHF; (3) the prognosis of new-onset CHF in the community, including the prognosis of patients with CHF and preserved ejection fraction; (4) the use of vasodilators and other therapies for CHF after diagnosis.

Drug/Procedures Used:

The Rochester Epidemiology Project and the Mayo Clinic unit record, indexes of medical records from essentially all sources of medical care available to and used by the Olmsted County population, was assessed to determine all new diagnoses of CHF from January 1,1991, through December 31,1991.

Principal Findings:

A first diagnosis of congestive heart failure was made in 216 patients in Olmsted County, Minnesota, in 1991. The number of patients with heart failure increased with advancing age: 88% were >=65 years and 49% were >=80 years. Survival was 86% at 3 months, 76% at 1 year, and 35% at 5 years. Advanced age (R.R. 1.04, p=0.0001) and moderate to severe NYHA functional class (R.R. 1.47, p=0.027) were negative predictors of long-term survival. Of the 216 patients, 63% had an assessment of ejection fraction. In these patients, 57% had systolic dysfunction (ejection fraction <50%). Survival adjusted for age, sex, NYHA class, and coronary artery disease was not significantly different between patients with preserved and those with reduced systolic function (relative risk, 0.80; p=0.369). ACE inhibitors were used in only 44% of the total population with CHF.

Interpretation:

This was the first large community-based study to show that among patients with CHF who undergo assessment of ventricular function, nearly as many have preserved systolic function as have reduced ejection fraction. Nearly half of CHF cases in the community setting occur in the very elderly (age >=80). Prognosis for CHF in the community is extremely poor, regardless of the level of systolic function. Diagnostic and therapeutic methods may be underused in the community.

References:

Circulation. 1998;98:2282-2289.

Clinical Topics: Heart Failure and Cardiomyopathies, Atherosclerotic Disease (CAD/PAD), Acute Heart Failure

Keywords: Internship and Residency, Prognosis, Risk, Coronary Artery Disease, Minnesota, Ventricular Function, Left, Heart Failure, Stroke Volume, Medical Records


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