Leukotriene biosynthesis in coronary artery disease. Results of the Leukotrienes and Thromboxane In Myocardial Infarction (LTIMI) study.

INTRODUCTION Leukotrienes (LTs) may be involved in atherosclerosis and may contribute to cardiovascular outcomes in CAD. OBJECTIVES    We aimed to compare the baseline LT production in patients with stable CAD (sCAD) and myocardial infarction (MI), and to assess whether an increased LT production is associated with major adverse cardiovascular events (MACEs) at 1 year after MI. PATIENTS AND METHODS    LTIMI (Leukotrienes and Thromboxane In Myocardial Infarction) was a single‑center, prospective, observational study of patients with stable sCAD and MI. Urinary leukotriene E4 (LTE4) levels were measured on admission, at 1 month, and at 1 year, using high‑performance liquid chromatography tandem mass spectrometry. RESULTS    Of the 404 patients screened, 289 were enrolled (110 with sCAD and 179 with MI; mean [SD] age, 63.9 [10.9] years). Patients with MI had higher median (interquartile range [IQR]) levels of log‑transformed LTE4 (logLTE4) than those with sCAD (4.74 pg/mg creatinine [4-5.45] vs 4.51 pg/mg creatinine [3.99 4.86], respectively; P <0.001). Median (IQR) logLTE4 levels in patients with MI significantly decreased at 1 month to 4.37 pg/mg creatinine (3.81-4.95), and at 1 year to 4.16 pg/mg creatinine (3.55-4.85). The baseline urinary logLTE4 levels were similar in patients with MACEs and those without MACEs (median [IQR], 4.78 pg/mg creatinine [4.01-5.56]) and 4.68 pg/mg creatinine [3.97-5.28], respectively; P >0.05). Multiple regression showed no relation between LTE4 levels and the incidence of MACEs. CONCLUSIONS    LT production assessed by urinary LTE4 excretion is higher in patients with MI than in those with sCAD; however, LTE4 levels at baseline do not differ between patients with and without MACEs at 1 year after MI.