Introduction:
Acute myocardial infarction (MI) due to unprotected left main coronary artery (ULMCA) as an infarct-related artery is a rare disease with a poor in-hospital and long-term outcome. A nearly linear correlation between post-percutaneous coronary intervention (PCI) Thrombolysis in Myocardial Infarction (TIMI) 3 grade and improved outcome is well known, however poorly reported in regard to ULMCA.

Aim:
To assess the impact of pre- and post-procedural TIMI flow grade on outcomes of emergency PCI in men and women with acute MI due to the ULMCA disease.

Material and methods:
Data were selected from the ongoing, nationwide, multicenter, prospective, observational registry. The study group consisted of 643 consecutive patients hospitalized during one year with acute MI with ULMCA as an infarct-related artery. Data analyzed included information from patients' history, coronary risk factor profile, clinical presentation, therapeutic approach and adjunctive treatment. The primary end-points were in-hospital, 30-day, and 12-month mortality.

Results and discussion:
There were 184 women and 459 men (28.6% vs. 71.4%), P < 0.0001. PCI was performed in 120 women and in 279 men (65.2% vs. 60.8%; P = 0.3) with a high rate of post-procedural TIMI 3 flow (87.6% vs. 82.1%; P = 0.17). Successful PCI defined as the restoration of TIMI flow grade 3 was the only factor decreasing in-hospital (OR 0.1, 95% CI (0.05–0.23), P < 0.0001) and 12-month (OR 0.2, 95% CI (0.13–0.3), P < 0.0001) mortality.

Conclusions:
In patients with acute MI survival after ULMCA PCI depended on TIMI grade before and after the procedure.