Serelaxin Shows Promise in Treating Acute Heart Failure

Patients hospitalized with acute decompensated heart failure treated with the drug serelaxin experienced decreased death rates, reduced time in the intensive care unit, and improved symptoms.

According to results from the RELAXin in Acute Heart Failure (RELAX-AHF) Trial presented at the American Heart Association 2012 Scientific Sessions, in Los Angeles, California, patients who were treated with serelaxin experienced a significant reduction in heart failure symptoms, had shorter overall duration of hospital stay, and had fewer episodes of worsening heart failure symptoms, compared with patients who received standard care plus placebo.

The novel drug serelaxin relaxes the blood vessels and improves blood flow to organs. It is a recombinant form of the human hormone relaxin-2, which is “known to mediate the hemodynamic changes that occur during pregnancy, such as increased cardiac output, increased renal blood flow, and increased arterial compliance.”

The study was conducted between October 2009 and February 2012. It included 1,161 patients in 11 countries, at 96 study sites. Researchers randomized adult patients (age 18 and older) who were hospitalized for acute heart failure (AHF) to receive either 30 mcg/kg per a day of serelaxin or a placebo via 48-hour continuous infusion. Treatment was administered “within 16 hours of hospitalization for heart failure-related symptoms of shortness of breath with evidence of decline in kidney function.”

Patients excluded from the study include those who had current or planned treatment with any IV therapies, were breast feeding, had AHF and dyspnea from non-cardiac causes, had infections requiring IV antibiotics, or were experiencing any acute cardio events.

Two-thirds of the study cohort was Caucasian men. The average age of study participants was 72. Many patients had multiple comorbidities, including high blood pressure (87%), high cholesterol (53%), ischemic heart disease (52%), atrial fibrillation (52%), diabetes (48%), and stroke (14%).

There were 37% fewer all-cause deaths after six months among patients who received the 48-hour IV infusion of serelaxin, including fewer cardiovascular-related deaths.

Lead study author John Teerlink, MD, FAHA, University of California, San Francisco, and San Francisco VA Medical Center said, “Our findings suggest serelaxin holds promise as the first evidence-based therapy for acute heart failure to substantially improve patients’ symptoms and clinical outcomes, including death.”

“The more important issue here is the apparent effect on all-cause mortality. If nothing else, this trial is at least making us think about what is going on in acute heart failure and what we're trying to do for this condition." said John McMurry, MD, of the University of Glasgow in Scotland, during a panel discussion about the study.

In summary, in the RELAX-AHF study, patients with acute heart failure treated with serelaxin experienced:

• Improved dyspnea relief
• Decreased congestion
• Reduced diuretic use
• Less worsening of heart failure
• Shorter hospital stay
• Improved cardiovascular and all cause survival