Difficulty Breathing? Could Be a Sign of Heart Failure

August 24, 2010

Dyspnea, or difficulty breathing, is a key symptom in acute heart failure. Lack of relief can result in longer hospital stays and poorer outcomes.

Researchers report that dyspnea (difficulty breathing) is a key prognostic symptom in acute heart failure and that failure to alleviate this condition can lead to prolonged hospitalization and worsening of patients’ heart failure symptoms.

The European Society of Cardiology (ESC) reports that a clinical trial investigating the peptide hormone relaxin in the treatment of acute heart failure demonstrated that lack of dyspnoea relief is associated with poor short- and medium-term outcomes and that levels of dyspnea “are also related to prognosis and hence are important and meaningful targets of therapy.”

Professor Marco Metra, Cardiology Department of the University of Brescia, Italy, and colleagues, in a study published in the European Journal of Heart Failure, that “early and persistent relief of dyspnoea is stubbornly difficult to achieve, with around three-quarters of patients in the study unable to find ‘moderate to marked’ symptom relief (when measured on a rating scale).” In the study, 25% of patients developed “recurrent breathing symptoms and worsening signs of heart failure during their first five days of hospitalisation.”

Using preliminary data from the Study to Evaluate the Efficacy and Safety of Relaxin in Subjects with Acute Heart Failure (RELAX-AHF), the researchers found that early dyspnea relief was observed in only 25% of all patients, with five-day improvement in symptoms in only one in three (32%) of patients who received placebo; similar results were seen in 50% of patients who were given relaxin. According to the news release from the ESC, “worsening heart failure to day 5 was observed in 21% on placebo and 14% on relaxin. This lack of ongoing dyspnoea improvement and worsening heart failure were associated with a longer length of hospital stay and deteriorating 60-day outcomes.”

For RELAX-AHF, 232 patients who were admitted to the hospital with acute heart failure were randomized to placebo or four doses of relaxin. Participants were “evaluated immediately and up to day 5 for dyspnoea relief and worsening signs of heart failure. Patients were followed for a further six months.”

Based on these results, Metra and colleagues have proposed that dyspnea is “a predictor of better outcome to treatment and thus a major goal of therapy in AHF,” according to the news release. "The early assessment of dyspnoea relief may add important prognostic information beyond the information available at the time of admission," said Metra.

Metra said that results from early studies of relaxin in heart failure “have been encouraging.” He noted that “administration of relaxin in this preliminary RELAX-AHF trial was associated with a trend towards improvement in persistent dyspnoea and prevention of worsening heart failure compared with placebo.”

According to Metra, even when physicians follow guideline recommendations for the treatment of acute heart failure, outcomes are often “disappointing,” and new medications “have not shown convincing benefits.”

The study, “Dyspnoea and worsening heart failure in patients with acute heart failure: results from the Pre-RELAX-AHF study,” is available online at the website of the European Journal of Heart Failure.