Post-Myocardial Infarction Guideline-Recommended Therapy Utilizing Sankey Diagrams Among Medicare Beneficiaries.

Purpose: To describe 2-year post-myocardial infarction (MI) longitudinal patterns of guideline- directed medical therapy (GDMT) and cardiac rehabilitation (CR) participation with Sankey diagrams.

Methods: Eligible Medicare beneficiaries were aged 66 to 95 years with an acute MI (International Classification of Diseases-9-CM discharge codes of 410.xx excluding 410.x2) hospital admission between January 1, 2014 and September 30, 2015 and ≥1 follow-up CR sessions. We defined GDMT (angiotensin converting enzyme-inhibitor or angiotensin receptor blocker, statin, and β-blocker) use as having at least a 21-day supply available during a 30-day window. We stratified CR participation by days with claims (1-11, 12-23, ≥ 24). Population level trends of 6 GDMT combinations, CR participation, and death were depicted with Sankey diagrams.

Results: Study population consisted of 5793 beneficiaries, 72% of whom had ≥1 GDMT pre-MI, 93% had ≥1 GDMT at baseline, and 45% initiated CR by 30 days post-MI. A median 23% of CR participants did not flow from low to moderate CR participation each month. At 1-year post-MI, 37% of beneficiaries without pre-MI GDMT and 33% of beneficiaries with pre-MI GDMT concluded CR early. Between 9% and 16% of beneficiaries without pre-MI GDMT and 2% to 6% beneficiaries with pre-MI GDMT did not have a GDMT fill post-MI. On average, 4% to 5% of beneficiaries switched from β-blocker + statin to another GDMT group post-MI each month.

Conclusions: Describing patterns of secondary prevention method utilization with Sankey diagrams can identify intervention populations, such as groups with inconsistent CR participation, primary nonadherence to new medications, and volatile medication persistence.