According to the Los Angeles County Department of Health, coronary heart disease is the leading cause of death in the county. Many individuals with coronary heart disease die as a result of heart failure. According to UCLA Health System, this chronic, progressive disease affects millions of individuals and results in morbidity, the expenditure of significant healthcare resources, and substantial costs. On February 21, UCLA published the results of their research online in the Journal of the American Heart Association. They reported that a combination of several important guideline-recommended therapies for heart failure treatment resulted in up to a 90% improvement of survival for the next two years.
The study authors noted that although certain therapies are recommended for heart failure patients in the national guidelines of the American College of Cardiology and the American Heart Association, their study is the first to examine the specific contribution each of these therapies contribute to improved survival in a real-world clinical practice. “We found incremental and cumulative improvement in the odds of two-year survival rates as each of these guideline-recommended therapies was implemented with patients," noted the study's first author, Dr. Gregg Fonarow, UCLA's Eliot Corday Professor of Cardiovascular Medicine and Science and director of the Ahmanson–UCLA Cardiomyopathy Center at the David Geffen School of Medicine at UCLA. Dr. Fonarow added that the findings also provide further rationale for employing performance-improvement systems and disease-management programs to ensure the implementation of recommended therapies in eligible heart failure patients.
The researchers reviewed medical data from 1,376 patients who died at 24 months, compared with 2,752 controls who survived to 24 months. The data was derived from the Registry to Improve the Use of Evidence-Based Heart Failure Therapies in the Outpatient Setting (IMPROVE HF), which incorporates patients from 167 cardiology-practice clinics across the nation. They specifically reviewed patients who had weakening function in the heart's left ventricle, which is the heart chamber that pumps blood throughout the body. Heart failure occurs when the left ventricle is unable to pump an adequate blood supply to the body.
The investigators evaluated seven specific guideline-recommended therapies:
- Three types of heart failure medications: beta blockers, aldosterone antagonists, and angiotensin-converting enzyme inhibitors or angiotensin receptor blockers.
- Cardiac resynchronization therapy, which helps coordinate heart contractions.
- Anticoagulant therapy for atrial fibrillation, to prevent clot formation in patients with an irregular heart beat.
- Implantable cardioverter-defibrillator devices, to deliver electrical shocks if potentially fatal heart-rhythm abnormalities occur.
- Patient education.
The investigators found that as each therapy was added, the overall survival rate incrementally increased. Compared to no treatment at all, when beta blockers alone were used, the chance of two year survival increased by 39%; however, when several other therapies were added, the two year survival increased to 81-90%. They also noted that the survival benefit was found to plateau once a patient sequentially received four to five therapies.
Dr. Fonarow explained, "Together the cumulative 24-month survival benefits of these therapies are impressive." He added, "High-quality, patient-centered outcomes research is a national priority and can better inform clinical decision-making. This study provides patients, clinicians, purchasers and policymakers with compelling evidence of the incremental improvements in clinical outcomes for patients with heart failure that can be achieved with guideline-recommended therapies."
With the exception of aldosterone antagonists, each individual therapy was associated with a survival benefit. The greatest benefit was obtained from beta blockers and cardiac resynchronization therapy; they decreased the mortality rate by 42% and 44%, respectively. Dr. Fonarow explained that being able to independently rate these heart failure therapies might provide a basis for choosing between treatments when a choice needs to be based on factors such as cost, tolerance, or compliance. In regard to aldosterone antagonists, he noted that multiple randomized clinical trials have demonstrated the benefits of aldosterone antagonist therapy in heart failure patients; thus, he felt that additional studies in an outpatient setting were indicated to be done to evaluate the real-world clinical effectiveness of these agents.
Comments