Does a Rise in Serum Creatinine Affect Post-hospitalization Mortality and ESRD in Elderly MI Patients?
Background: Previous studies found an association between small changes in serum creatinine during hospitalization and short-term mortality. Data has shown patients experiencing a rise in creatinine at the time of CABG have increased in-hospital and long-term follow-up mortality.
Study design: Retrospective cohort study
Setting: Nationwide Medicare database of acute MI hospitalizations.
Synopsis: The authors reviewed outcomes data for 87,094 patients hospitalized for acute myocardial infarction (MI) from 1994-1995 with follow-up data through 2004. Patients were classified into groups with no rise in creatinine during hospitalization and those with rises of 0.1 mg/dL, 0.2 mg/dL, 0.3-0.5 mg/dL, and 0.6-3 mg/dL.
Compared with patients with no rise in creatinine, a rise of 0.1 mg/dL was associated with an adjusted hazard ratio of 1.45 for end-stage renal disease (ESRD) and 1.14 for post-hospitalization death during long-term follow-up. An incremental increase in poor outcomes was seen with more dramatic increases in creatinine, with patients in the group with a 0.6-3 mg/dL rise in creatinine having an adjusted hazard ratio of 3.26 for ESRD and 1.39 for post-hospitalization death. Among patients with a creatinine rise, the absolute risk of mortality (15% annually) was greater than that of ESRD (0.3% annually).
Hospitalists should note limitations of this retrospective study, including its restriction to hospitalized elderly patients.
Bottom line: Even small rises in serum creatinine during acute hospitalization for MI are associated with long-term risk for death and ESRD in elderly patients.
Citation: Newsome BB, Warnock DG, McClellan WM, et al. Long-term risk of mortality and end-stage renal disease among the elderly after small increases in serum creatinine level during hospitalization for acute myocardial infarction. Arch Intern Med. 2008;168(6):609-616.
Does Direct-to-patient Communication Improve Adherence to Beta-blocker Therapy Following an MI?
Background: The joint American Heart Association and American College of Cardiology guidelines have specific treatment recommendations regarding care of a patient post-myocardial infarction (MI). A key component of this regimen is beta-blocker therapy. Beta-blockers routinely are prescribed at hospital discharge following MI; however, patient adherence has been shown to decline substantially over time.
Study design: Cluster randomized control trial.
Setting: Four health maintenance organizations in Boston, Minneapolis, Atlanta, and Portland, Ore.
Synopsis: 836 post-MI patients were given a beta-blocker prescription upon discharge from the hospital. The intervention group received two mailed communications. The first was a personalized, simply worded letter from a health plan physician-administrator, followed two months later by a similar letter with a brochure. Mailers were low cost and easily replicable; they addressed the importance of these medications, the risks of non-adherence, and adverse effects.
The primary outcome measure was beta-blocker adherence. Medication adherence was analyzed as a continuous measure and as a monthly proportion of days covered (PDC) of 80% or greater. Across all months of follow-up, a mean of 64.8% of intervention patients had a PDC of more than 80% compared with 58.5% of control group patients (number needed to treat=16). The intervention group was 17% more likely to have a PDC of 80% or greater over the entire post-intervention period.
These interventions were studied in a prepaid integrated care delivery system—limiting generalization to other insurance types. Nevertheless, finding ways to improve patient compliance and decrease recurrent cardiac events is liking to result in cost saving to any healthcare plan.
Bottom line: A low-cost direct-to-patient communication effort can have a positive effect on beta-blocker adherence following MI.
Citation: Smith DH, Kramer JM, Perrin N, et al. A randomized trial of direct-to-patient communication to enhance adherence to beta-blocker therapy following myocardial infarction. Arch Intern Med. 2008;168(5):477-483. TH