Can Dyspnea and Fatigue Signal Key Outcomes in HF Patients?

September 13, 2010

New research looks at the use of dyspnea in predicting outcomes, cognitive patterns in chronic heart failure, and the incidence of ICD shocks.

Findings from a study conducted by researchers at Chang Gung Institute of Technology in Taoyuan, Taiwan, showed that trends in dyspnea and fatigue can predict health-related quality of life outcomes in patients with heart failure. The study was one of several presented during the Nursing Research Award session Monday at the HFSA 14th Annual Scientific Meeting that looked at how recent research can impact the care of patients with heart failure (HF).

In their research, lead author Tsuey-Yuang Huang and colleagues set out to determine whether trends in fatigue and dyspnea, a condition characterized by unpleasant or uncomfortable breathing, can adversely impact quality of life (QoL) in HF patients. Participants were asked to complete a pulmonary function questionnaire, and were placed into three groups based on the intensity of dyspnea and fatigue at baseline, three months, and 12 months.

According to Huang, Kaplan-Meier survival analysis was used to determine whether dyspnea and fatigue trends pointed to QoL and event-free survival. Of the 122 participants, the majority of whom were male, patients in the group with the most moderate intensity demonstrated longer event-free survival than those in the more severe groups, and health-related QoL in the group with the most severe intensity was worst of the three groups.

The researchers concluded that trends in both dyspnea and fatigue over the course of one year predicted health-related QoL in HF patients. However, “only trends in fatigue predicted event-free survival,” said Huang. These data, she pointed out, “demonstrate the value of tracking symptoms over time to determine symptom trajectories.

In another study, Lisa C. Bauer, RN, of University of California, San Francisco, and colleagues examined “Cognitive Patterns in Chronic Heart Failure.” The goal of their research was to identify patterns of cognitive impairment in patients with systolic and diastolic dysfunction, as previous studies looked primarily or exclusively at patients with systolic dysfunction.

Bauer and colleagues used the Repeatable Battery for Assessment of Neuropsychological Status, as well as letter fluency, to measure cognitive impairment in a sample of patients with systolic and diastolic dysfunction. They found that patients with systemic dysfunction demonstrate different cognitive impairment than patients with diastolic dysfunction, particularly in terms of immediate versus delayed memory.

The researchers concluded that heart failure etiology contributes to cognitive impairment patterns demonstrated in chronic HF patients, and that different patterns may require different compensatory interventions. Replication of these findings, they noted, is crucial, due to the small sample size.

Finally, Tamra L. Ward and colleagues from Creighton University, Omaha, NE, examined the potential effect of heart disease management on the incidence of implantable cardioverter-defibrillator (ICD) shocks. According to Ward, the benefits of ICD have been demonstrated through clinical trials, but it still wasn’t clear whether there is “a special component that is responsible for reducing the incidence of ICD shocks.”

Working under a hypothesis that patients who are part of a disease management program “will have decreased incidence of ICD shocks compared to those in usual managed care,” Ward and colleagues performed retrospective analysis of 223 patients, and found that the overall shock rate was lower than expected (one-third of patients were shocked in the first 1-2 years). After adjusting several factors, including age, gender, sex, indication for ICD, LVEF, and medication use, it was concluded that participation in a disease management program is an independent risk predictor for fewer ICD shocks. Aggressive HF management and surveillance may reduce the incidence of ICD shocks, they found.