JACC in a Flash: Measuring Quality by the Dose in Post-AMI Patients

Although they are designed to quantify the use of evidence-based treatments and improve the quality of care, current performance measures fail to assess the entire picture of a patient’s treatment. They assess only whether a patient is prescribed certain medications, not the potency or dosing of the treatment. Patients, then, could be receiving the appropriately lower doses of medications at discharge, but these therapies are never up-titrated to levels with established clinical benefit—leading to sub-optimal dosing for secondary prevention of acute MI (AMI). Are treated patients fulfilling the requirements of performance measures, while receiving relatively ineffective therapy?

In an article appearing in JACC, Susan V. Arnold, MD, MHA, and colleagues examined the prescribing patterns of medications (beta-blockers, statins, and angiotensin converting enzyme inhibitors [ACE] or angiotensin II receptor blockers [ARB]) in a large, multicenter cohort of patients hospitalized with AMI.

At hospital discharge, most eligible patients were discharged on some dose of the three secondary prevention medications, and hence ranked well on performance measures: beta-blockers, 93%; statins, 88%; ACE/ARB, 88%. However, 40% of patients were discharged on low doses of beta-blockers despite signs of LV systolic dysfunction, and only 19% of patients considered eligible for titration were discharged on goal doses. Patients without LV systolic dysfunction were discharged on goal doses at similar rates (14.6% vs. 16.3%).

Twelve months after AMI, ranking on performance measures was significantly lower: only 60-70% of patients reported taking any dose of the medications. Goal doses of medications were also achieved less frequently than at discharge, with only 12%, 26%, and 32% of eligible patients on goal doses of beta-blockers, statins, and ACE/ARBs, respectively. Patients with LV systolic dysfunction on goal doses of beta-blockers was greater at 12 months than those without (16.2% vs. 9.2%, respectively).

As predicted, up-titration of medication dose during outpatient follow-up occurred infrequently, with dose increases in only 20.4% of patients on beta-blockers, 24.4% of patients on statins, and 31.9% of patients on ACE/ARBs. Adjustment showed that patients discharged on a goal dose of medication were 6–8 times more likely to be on a goal dose at the 12-month follow-up than those not discharged on goal medication doses:

  • beta-blockers (adjusted OR = 6.08 [95% CI 3.70-10.01])
  • statins (adjusted OR = 8.22 [95% CI 6.20-10.90])
  • ACE/ARBs (adjusted OR = 5.80 [95% CI 2.56-13.16])

Overall, the prescribed doses for these medications were below those examined in clinical trials, with nearly 85% of patients discharged on beta-blocker doses and two-thirds of patients discharged on statin and ACE/ARB doses that were substantially below (<75%) the doses with established efficacy.

“This is particularly concerning in the case of statins, where there should be few clinical reasons not to start a patient on a goal statin dose early in the AMI hospitalization,” Dr. Arnold and colleagues wrote. “These findings highlight the limitation of current performance measures that credit providers for using any dose of medication, even if well below doses with established clinical benefit.”

The investigators identified several reasons for the general lack of active up-titration in the outpatient setting: clinicians may not view up-titration of as an important therapeutic goal, are unaware of the target medication doses (i.e., the doses with proven clinical efficacy), or have other competing medical issues that they need to address during follow-up visits. Perhaps, Dr. Arnold and authors suggest, rates of medication use at clinically-proven doses might be improved if performance measures incorporated assessments of medication dosing. Performance measures, in turn, may need to incorporate doses of medications to better achieve their goal of truly optimal medical therapy.

Arnold SV, Spertus JA, Masoudi FA, et al. J Am Coll Cardiol. 2013;62:1791-1801.

Keywords: Follow-Up Studies, Outpatients, Patient Discharge, Hospitalization

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