Evaluation of the TIMI risk score for secondary prevention for predicting ischemic and bleeding events in patients with recent myocardial infarction
Authors: Hansen K W , Sorensen R , Bjerking L H , Prescott E , Galatius S 
Published: October 2022

Abstract

Background
Patients with acute myocardial infarction (MI) have a substantial risk of ischemic events, which must be balanced against the risk of bleeding imposed by modern antiplatelet agents. Both ischemic and bleeding risk are modified by the presence or absence of several risk factors. The TIMI Risk Score for Secondary Prevention (TRA2°P) is a simple and promising risk stratification scheme for predicting risk of atherothrombotic events at 3 years. It was developed using 8598 placebo-treated patients of the TRA 2°P -TIMI 50 trial and has only been evaluated in small selected cohorts.

Purpose
We evaluated the TRA2°P risk score (age≥75 years, congestive heart failure, hypertension, diabetes mellitus, prior stroke, prior coronary artery bypass surgery, peripheral artery disease, renal dysfunction, current smoking) in a large contemporary cohort of patients with a recent myocardial infarction (MI).

Methods
Nationwide administrative health care data on hospitalizations, procedures, medications, and outcomes were abstracted from the Danish registries. We included all patients ≥30 years hospitalized with a first acute MI between 1 January 2005 and 31 December 2011 who were alive and event-free 30 days after discharge. Patients with an indication for oral anticoagulation were excluded. Data on smoking status were not available. The main outcome was a composite of cardiovascular death, non-fatal MI and ischemic stroke. Bleedings requiring hospitalization were also investigated. Patients were followed until death, emigration, or a total of 3 years; whichever came first.

Results
A total of 34,479 patients were included (mean age 67±14 years, 35% females, 66% had prior revascularization, 90% received aspirin, 79% a P2Y12-inhibitor, 86% lipid-lowering medication and 82% beta-blockers). During 3-year follow-up, the main composite outcome was reached in 4677 patients (cumulative incidence, 13.6% [CI95%, 13.2–13.9%]) and 746 patients (2.2% [2.0–2.3%]) had a bleeding requiring hospitalization.
The TRA2°P risk score demonstrated a robust absolute and relative risk gradient for both the composite ischemic endpoint and bleeding requiring hospitalization (Table 1). The absolute risk of bleedings remained lower than the risk of atherothrombotic events. This is summarized in Figure 1, where results are presented by low, intermediary, and high TRA2°P risk score, as applied in the derivation cohort. The C-statistic of the TRA2°P risk score was 0.69 for the composite outcome, comparable to that of the derivation cohort.

Conclusions
The TRA2°P risk score identified patients at increased risk of atherothrombotic events at 3 years and a pattern of increasing absolute risk difference between ischemic and bleeding events. The role of the TRA2°P risk score in identifying patients who may benefit from extended antiplatelet treatment merits further evaluation. Also, the TRA2°P risk score may have wide applications in register-based research of post MI patients.

Funding Acknowledgement
Type of funding sources: Public hospital(s). Main funding source(s): Bispebjerg and Frederiksberg University Hospital