Heart failure in the United States is becoming increasingly common as the population ages. It's estimated that 5.1 million Americans have diagnosed HF and about one million are hospitalized annually for related symptoms.
The most common type is left-sided HF, where the heart cannot pump enough blood to meet the demands of the body, also known as a reduced ejection fraction.
In a recent study, published in the New England Journal of Medicine, researchers at Brigham and Women s Hospital examined data from 8,399 patients in the PARADIGM-HF study. This is the largest clinical trial conducted for HF. The participants were treated with either enalapril (standard of care) or sacubitril-valsartan (treatment). What they found was participants who received the experimental combination pill had a projected increase in life expectancy of one and half to two years, as compared to enalapril.
These results help both patients and their physicians understand the impact of switching from the standard of care to sacubitril-valsartan, in terms of a benefit that they can easily understand, according to Scott D. Solomon, MD, senior author and director of Non-Invasive Cardiology at Brigham and Professor of Medicine at Harvard Medical School. Patients want to know how much longer they are going to live, rather than how much their risk will be reduced.
Half of those diagnosed with HF will die within five years of diagnosis. Despite improvements in treatment, mortality in these patients is still unacceptably high, further emphasizing the need for new, more novel therapies.
HF patients are classified according to the New York Heart Association (NYHA) Functional Classification I IV, which ranges from least to most severe. This system provides a simple method of classifying the extent of heart disease and to provide a common language for physicians to communicate.
The classification system also serves to guide blood pressure reduction therapy for HF patients that have also been shown to confer a survival benefit. These include several classes of medications, which are considered the standard of care. The first and most important is an angiotensin converting enzyme inhibitor (ACE-I) or angiotensin II receptor blockers (ARBs for those patients who develop a cough with ACE-I).
Other classes include beta-blockers (which also have the added benefit of reducing angina, while having anti-arrhythmic effects) and aldosterone receptor antagonists. African Americans, specifically, have a survival benefit with the use of a combination that includes isosorbide dinitrate and hydralazine. Other important medications such as diuretics, a cornerstone of HF therapy, will improve symptoms but do not necessarily equate to improved survival.
Sacubitril-valsartan is the newest kid on the block. It is known as an angiotensin receptor-neprilysin inhibitor (ARNI). It was recently approved by the FDA in the treatment of HF. This drug generated considerable buzz in HF circles for its ability to significantly reduce cardiovascular-related death, hospitalizations due to HF and all-cause mortality. The FDA expedited the drug's review, awarding it a fast-track designation, because of the promise it held in treating a serious disease.
This study is important, in that this medication adds to the limited cache of existing therapy in our arsenal to improve outcomes in HF patients. It could possibly represent the future cornerstone of chronic heart failure therapy.