Effectiveness of Strategies to Improve Outcomes after Hospitalization for Acute Myocardial Infarction in Older Adults

Acute myocardial infarction (AMI) is consistently ranked as one of the top five most expensive conditions billed
to Medicare and has been the target of several cost containment measures, including Medicare’s Hospital
Readmissions Reduction Program. To improve outcomes after AMI hospitalizations, payers have implemented
public reporting, financial penalties, and alternative payment models that incentivize the assumption of financial
risk such as capitation. These measures have not been accompanied by evidence-based guidelines on how
health systems can improve outcomes after hospitalization. An impediment to such guidance has been an
incomplete understanding of patient-level factors that may influence the effectiveness of strategies to improve
post-AMI hospitalization outcomes as applied in real-world settings. Notably, 30% of patients hospitalized for
AMI are age ≥ 75. These patients have lower physiologic reserve and more functional impairments, including
those in cognition and physical capabilities, than younger patients. In the SILVER-AMI study, we enrolled 3041
patients age ≥ 75 hospitalized for AMI at 94 hospitals. The primary objective was to evaluate the contribution of
functional impairments and geriatric conditions to improving risk prediction for mortality within 6 months of
hospital discharge. The premise of the SILVER-AMI study was that risk prediction at the time of discharge could
identify high-risk patients who might benefit from more intensive post-hospital care. Findings from SILVER-AMI
have demonstrated that functional impairments substantially improve risk prediction for important outcomes. We
did not obtain Medicare data in this study so could not examine strategies being deployed in an effort to improve
post-AMI outcomes. The overall objective of this proposal is to refine our understanding of the impacts of
home health care (HHC) (Aim 1), early outpatient care (Aim 2), and Medicare Advantage (MA) (Aim 3) after AMI
hospitalization by examining their effects in the context of functional impairments and illness severity. We will
focus on outcomes of primary importance to older patients, including “home days” (days alive out of the hospital
and other inpatient facilities) and health status, as well as disease-specific outcomes of relevance post-AMI. We
will merge data from the SILVER-AMI study with Medicare data to achieve our aims. Combining these data
sources will afford us the unique opportunity of accounting for an array of rigorously assessed covariates that
are not generally available in studies using only administrative data and to identify patients who may benefit most
from post-discharge services. In addition to accounting for a rich array of measured confounders, we will employ
advanced statistical techniques to address bias from unmeasured confounding. We have assembled a team with
a track record of collaboration and expertise in cardiovascular outcomes, home health care, outpatient care
delivery, epidemiology, and biostatistics. This hypothesis-driven research will leverage the most comprehensive
set of data on functional impairments and geriatric conditions collected during AMI hospitalization on a large,
national cohort to inform strategies to improve outcomes of importance to older patients.

Grant Number: 5R01HL160822-03
NIH Institute/Center: NIH
Principal Investigator: Sarwat Chaudhry