Clinical and Angiographic Correlates and Outcomes of Suboptimal Coronary Flow in Patients with Acute Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

OBJECTIVES: The purpose of this study was to determine the clinical and angiographic correlates and outcomes of patients with suboptimal coronary flow after primary percutaneous coronary interventions (PCI). BACKGROUND: The clinical and angiographic correlates and outcomes of Thrombolysis in Myocardial Infarction (TIMI) ≤2 flow in patients treated with primary PCI are not known. METHODS: We evaluated 3,362 patients with ST elevation myocardial infarction enrolled in various Primary Angioplasty in Myocardial Infarction trials, who underwent primary PCI. RESULTS: Post-procedural final TIMI ≤2 flow occurred in 232 (6.9%) patients. Multivariate analysis identified age ≥70 years (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.1 to 2.2), diabetes (OR 1.9; 95% CI, 1.3 to 2.7), symptom onset to emergency room presentation (OR 1.1; 95% CI, 1.1 to 1.2); initial TIMI ≤1 flow (OR 3.2; 95% CI, 1.9 to 5.5), and left ventricular ejection fraction <50% (OR 1.7; 95% CI, 1.2 to 2.4) as independent correlates of final TIMI ≤2 flow. In-hospital (composite of reinfarction, ischemic target vessel revascularization, or death, as well as these events individually) and one-year (reinfarction and/or death) events occurred more frequently in patients with TIMI ≤2 flow. The Cox proportional hazards model identified TIMI ≤2 flow to be independently associated with one-year mortality (hazard ratio 3.8, 95% CI, 2.5 to 5.7). CONCLUSIONS: Final TIMI ≤2 flow, although uncommon after primary PCI, was strongly associated with hospital and one-year adverse events. The clustering of final TIMI ≤2 flow in high-risk groups may partially explain the poor prognosis of these patients. Awareness of these risk factors may be useful to clinicians to triage and treat patients undergoing primary PCI.