Adhering to guideline-recommended secondary prevention therapies was linked to better outcomes and lower costs in the long run, investigators found.
After a myocardial infarction (MI), those who fully adhered to their medication for 6 months had an 18.9% rate of major adverse cardiovascular events (MACE) at the 2-year mark, significantly less compared to their peers that were non-adherent (26.3%, HR 0.73, 95% CI 0.61 to 0.87) or partially adherent (24.7%, HR 0.81, 95% CI 0.69 to 0.96).
Similarly, patients with atherosclerotic disease did better the more they adhered to their medication regimens within a year-long period, Valentin Fuster, MD, PhD, of The Mount Sinai Hospital in New York, and colleagues reported in the Journal of the American College of Cardiology.
In atherosclerotic disease patients, an 8.42% incidence of MACE was reported for the fully adherent; 17.17% for the non-adherent (HR 0.56, 95% CI 0.51 to 0.62); and 12.18% for the partially adherent (HR 0.76, 95% CI 0.69 to 0.84).
Fully adherent patients also saved hundreds in U.S. dollars in annual medical costs: the MI cohort saved $369 and $400 compared to the partially adherent and non-adherent, respectively; and the difference in atherosclerosis was $371 and $907, respectively.
“At least a 40% level of long-term adherence needs to be maintained to continue to accrue benefit,” the authors noted, suggesting that “novel approaches to improve adherence may significantly reduce cardiovascular events.”
Yet Paul W. Armstrong, MD, and Finlay A. McAlister, MSc, MD, both of Canada’s University of Alberta, did not agree with setting such a threshold based on this data.
“The fundamental message is that the more adherent patients were, the better they fared,” they wrote in an accompanying editorial.
“To make definitive statements about how much of a therapy needs to be taken to achieve a clinical effect, more refined data on actual medication consumption and pathophysiological surrogate markers, such as blood pressure or cholesterol levels, are needed.”
But like Fuster’s group, they also expressed interest in strategies to improve patient adherence, because “despite scores of studies drawing attention to this topic for >40 years, patient adherence with cardiovascular agents remains suboptimal.”
“The most promising approaches for improving patient adherence seem to be strategies to reduce dosing frequency or multidimensional, labor-intensive educational interventions revolving around monitoring and feedback. An often-neglected factor, which appears to be positively correlated with better patient adherence, is the frequency of physician follow-up and provider continuity,” wrote Armstrong and McAlister. “As a bare minimum, our first step as clinicians must be to routinely ask about adherence with all of our patients at every visit and to encourage them to take their medications as instructed.”
“We must learn from other disciplines, and make better use of information technology and behavior modification techniques, if we are to make progress. Our patients deserve it,” the editorialists urged.
Fuster and colleagues analyzed the claims records from Aetna Commercial and Medicare Advantage databases, culling data for patients who were hospitalized from 2010 to 2013 for MI (n=4,015) or atherosclerotic disease (n=12,976).
Patients were stratified according to their adherence to medication after investigators analyzed fill dates for their prescriptions for statins and ACE inhibitors. They were organized into tiers of the fully adherent (80% prescriptions refilled), the partially adherent (40%-79% filled), and the non-adherent (less than 40% filled).
But this made the study vulnerable to underestimation if patients were paying out-of-pocket and overestimation if patients did not actually take their medication as prescribed, the authors acknowledged.
“In addition, the consistent association between nonadherence and MACE hospitalizations may be the result of a healthy adherer effect, whereby adherent patients are probably less likely to engage in risky behaviors and more likely to follow medical recommendations,” they wrote.
Armstrong and McAlister listed yet other potential confounders in the Fuster’s investigation, such as temporary breaks in medication, pill splitting, free samples, and adequacy of dosing.
Fuster disclosed no conflicts of interest. He is the editor-in-chief of the Journal of the American College of Cardiology.
Co-authors reported being employed by Aetna.
Armstrong and McAlister declared no relevant relationships with industry.
Journal of the American College of Cardiology
Bansilal S, et al “Assessing the impact of medication adherence on long-term cardiovascular outcomes” J Am Coll Cardiol 2016; DOI: 10.1016/j.jacc.2016.06.005.
Journal of the American College of Cardiology
Armstrong PW, McAlister FA “Searching for adherence: Can we fulfill the promise of evidence-based medicines?” J Am Coll Cardiol 2016; DOI: 10.1016/j.jacc.2016.06.006.