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

Leukotrienes (LTs) may be involved in atherosclerosis and may contribute to cardiovascular outcomes in CAD. 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. LTIMI (Leukotrienes and Thromboxane In Myocardial Infarction) was a single‑center, prospective, observational study of patients with stable sCAD and MI. Urinary leukotriene $E_{4}$ ($LTE_{4}$) levels were measured on admission, at 1 month, and at 1 year, using high‑performance liquid chromatography tandem mass spectrometry. 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 $LTE_{4}$ ($logLTE_{4}$) 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) $logLTE_{4}$ 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 $logLTE_{4}$ 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 $LTE_{4}$ levels and the incidence of MACEs. LT production assessed by urinary $LTE_{4}$ excretion is higher in patients with MI than in those with sCAD; however, $LTE_{4}$ levels at baseline do not differ between patients with and without MACEs at 1 year after MI.