Temporal Trends of the Management and Outcome of Patients With Myocardial Infarction According to the Risk for Recurrent Cardiovascular Events

Background: Some patients are at higher risk for recurrent cardiovascular events following a myocardial infarction because of their clinical characteristics and comorbidities. Still, they are less often treated with guideline-recommended therapies. We examined trends for more than a decade in the treatment and outcome of patients with myocardial infarction according to the risk for recurrent cardiovascular events, using the Thrombolysis in Myocardial Infarction (TIMI) risk score for secondary prevention. Methods: This is a retrospective cohort study of patients after acute myocardial infarction who underwent percutaneous coronary intervention. Temporal trends were examined in the early (2004-2010) and late (2011-2016) time periods. Patients were stratified to low, intermediate, or high risk for recurrent cardiovascular events. Clinical outcomes included 30-day major adverse cardiovascular events (MACE), 1-year MACE, and 1-year mortality. Results: Among 4921 patients, 31% were low risk, 27% intermediate risk, and 42% high risk. Compared to lower-risk patients, high-risk patients were older, more commonly female, and had more comorbidities. They presented more often with non-ST elevation myocardial infarction and 3-vessel disease and were less likely to receive drug-eluting stents and potent antiplatelets, among other guideline-recommended therapies. In high-risk patients, 30-day MACE and 1-year mortality were higher. Comparing the early period to the late period, prescription rates increased for both statins and potent antiplatelets in all risk-groups. However, the rate of 30-day and 1-year MACE decreased principally in the high-risk group (from 9.9% to 5.5% and from 29.6% to 23.6%, respectively). Conclusion: Despite greater application of guideline-recommended therapies, patients at high risk after myocardial infarction are still relatively undertreated, which may adversely affect their prognosis. Nevertheless, they demonstrated the most notable improvement in clinical outcomes over time.