Randomized clinical trials on the use of aldosterone antagonists in eligible patients with heart failure have shown an incremental 15% to 30% reduction in all-cause mortality. They also have been associated with a substantial risk reduction in the likelihood of rehospitalization or first-time hospitalizations for heart failure. Due to robust supporting data, aldosterone antagonists have been advised as Class I recommendations in the American College of Cardiology/American Heart Association (AHA) guidelines since 2005 for individuals with moderate-to-severe heart failure and for those with post-myocardial infarction left ventricular dysfunction.
Slow Adoption of Evidence-Based Therapy
Despite data supporting its efficacy, adoption of aldosterone antagonist therapy for the treatment of heart failure in eligible patients has been slow. In the October 21, 2009 JAMA, my colleagues and I published an observational analysis among patients who were admitted with heart failure in 241 participating hospitals in the AHA’s Get With the Guidelines—Heart Failure (GWTG-HF) quality improvement program. This national quality improvement program was designed to promote adherence to guideline-based recommendations. The GWTG-HF program tracked aldosterone antagonist therapy use, indications, contraindications, and laboratories of 43,000 patients hospitalized with heart failure during the study timeframe. Results demonstrated that:
Less than one-third of heart failure patients eligible for aldosterone antagonist therapy (and without documented contraindications) were treated.
Prescription of aldosterone antagonists at discharge varied widely among hospitals.
Appropriate use of aldosterone antagonist therapy was less common among the elderly; Caucasians; those with lower systolic blood pressure; those without implantable cardioverter-defibrillators or pacemakers; those without a history of alcohol use or depression; and those with a history of renal insufficiency.
Rates of inappropriate use were infrequent.
Concerns about safety in the use of aldosterone antagonist therapy may contribute to the inconsistent and incomplete application of this life-prolonging therapy. Slow adoption by hospitals may be attributable to several factors, including the requirements for extra laboratory monitoring post discharge with aldosterone antagonist use. There have also been concerns about the risk of hyperkalemia and an increased creatinine level, two factors that can extend length of stay in the hospital. Importantly, slow adoption may be attributable to lack of systems and non-adherence to evidence-based practices.
Monitoring is Essential
Aldosterone antagonist therapy is not a treatment for all heart failure patients; clinicians should be aware of specific exclusion criteria for using these agents. Aldosterone antagonist therapy is indicated for select patients with heart failure. There are risks that may outweigh the benefits if it’s used without being closely monitored or if it’s used in inappropriate patients. Men with creatanine levels of above 2.5 mg/dl and women with levels above 2.0 mg/dl should not be treated. In addition, patients with hyperkalemia should not be treated with aldosterone antagonist therapy. Furthermore, the therapy shouldn’t be used in patients with hemodynamic instability or unstable renal function. When using aldosterone antagonist therapy, it’s critical to closely monitor potassium and renal function; patients who are unlikely to comply with the necessary laboratory monitoring are not candidates for treatment.
There are great opportunities to improve the use of evidence-based, guideline-recommended therapies for patients with heart failure. Although data are strong regarding the use of aldosterone agonists, many physicians continue to question their clinical effects. Research confirming the safety, efficacy, and real-world clinical effectiveness of aldosterone antagonist therapy will hopefully strengthen physician support and reinforce the importance of proper monitoring of the use of these drugs in heart failure patients.