Prediction of outcome after percutaneous coronary intervention for the acute coronary syndrome

The seven-component Thrombolysis In Myocardial Infarction (TIMI) score has been used to risk stratify, and to guide the medical management of, patients with unstable angina or non-ST-elevation myocardial infarction. We assessed the usefulness of the risk score in predicting in-hospital and 30-day outcomes in such patients who were undergoing percutaneous coronary intervention.

Using the TIMI score, 2501 patients with unstable angina or non-ST-elevation myocardial infarction were divided into low-risk (zero to two risk factors; n = 974), intermediate-risk (three to four risk factors; n = 1339), and high-risk (five to seven risk factors; n = 188) groups, and outcomes were compared.

Angiographic/clinical success and the rate of minor procedural events were similar among the three groups. A higher TIMI risk score was associated with more cardiac comorbid conditions and more complicated angiographic lesions: longer lesions (P = 0.0009), more thrombotic lesions (P = 0.03), more multivessel disease (P <0.0001), and more American College of Cardiology/American Heart Association type B2/C lesions (P = 0.05). Although the risk score did not predict interventional technical success or intraprocedural complications, a high score was associated with prolonged hospital stay, higher postprocedural peak troponin levels, and 30-day major adverse cardiac events. Stepwise logistic regression showed that in conjunction with lesion length and patient sex, a high score was an independent predictor of 30-day major adverse cardiac events (odds ratio = 2.3; 95% confidence interval: 1.1 to 4.1; C statistic = 0.62).

Although a higher TIMI risk score in patients with unstable angina or non-ST-elevation myocardial infarction who were undergoing percutaneous coronary intervention correlated with adverse clinical outcome, the score alone cannot be used to guide diagnostic or therapeutic strategies.