Patients with advanced heart failure have much better survival odds today than 20 years ago, but one in three still dies within three years of their diagnosis, researchers report.
"We are doing a good job of ensuring that patients receive the latest therapies for heart failure, but we still have a lot more work to do," study senior author Dr Tamara Horwich, an assistant professor of cardiology at the University of California, Los Angeles, David Geffen School of Medicine, said in a UCLA news release.
"It is very sobering that despite recent improvements, a third of advanced heart-failure patients aren't surviving past three years," Horwich added.
In people with heart failure, the heart can't effectively pump blood to the rest of the body. The increasingly common condition affects almost 6 million people in the United States.
Patients diagnosed with heart failure
For the study, published in the May issue of Circulation: Heart Failure, the researchers examined outcomes in more than 2 500 adults diagnosed with "heart failure with reduced ejection fraction," which is characterised by a weak heart muscle.
The patients were divided into three groups based on when they were treated: 1993 through 1998; 1999 through 2004; and 2005 through 2010. The researchers followed the patients for three years after they were diagnosed.
The study revealed dramatic differences. Patients treated from 1999 on were more likely to receive life-extending drugs, such as beta-blockers and aldosterone antagonists, as well as devices to help stabilise irregular heart rhythms, such as implantable cardioverter defibrillators. Whereas just 15.5% of patients used beta-blockers from 1993 to 1998, more than 87% used them between 2005 and 2010, the study pointed out.
The increased use of these treatments coincided with publication of the results of clinical trials, and the development of treatment guidelines, the researchers noted.
Prevalence of sudden cardiac death has also decreased, the study showed. At the three-year follow-up point, sudden death declined from 10.1% between 1993 and 1998 to 4.6% between 2005 and 2010.
Looking at the risk factors
Overall mortality rates also decreased over the course of the study. After taking risk factors such as age and gender into account, the investigators found that patients treated between 2005 and 2010 were 42% less likely than those in the earliest treatment group to die from any cause.
People who may have died suddenly in the past are living longer thanks to widespread use of implantable cardioverter defibrillators, the authors noted. This trend may be one reason why a shift occurred in the manner of death over the course of the study.
The researchers found patient mortality from progressive heart failure increased from 11.6% between 1993 and 1998 to nearly 20% between 2005 and 2010. The need for emergency heart transplants also increased over time.
Many of those patients would have died sooner in the earlier eras, said study author Dr Gregg Fonarow, a UCLA professor of cardiovascular medicine and science.
"For patients with the most advanced heart failure, treatment options used to be limited to heart transplantation - or face early death," Fonarow said in the news release.
"This study demonstrates that with improvements in medical therapy and availability of implanted devices, survival for these patients has improved considerably. What was once considered an end-stage, terminal disease state has, through implementation of innovative treatments, evolved into a manageable, but still challenging, condition," he explained.
However, more studies are still needed to explore new treatments for heart failure patients, the researchers added.
The US National Heart, Lung, and Blood Institute has more about heart failure.