Significance of blood taurine levels in patients with first time acute ischaemic cardiac pain.

We studied blood taurine levels of 91 consecutive patients admitted with first time cardiac pain suggestive of myocardial ischaemia. Blood taurine levels of patients with coronary arterial disease, but without a recent myocardial infarction (n = 36), at rest and after a maximal treadmill stress testing were also determined. The blood taurine level at the time of admission was significantly elevated (P less than 0.001) in patients with an acute myocardial infarction (n = 63) (271 +/- 98 mumol/l) and those with unstable angina (n = 22) [214 +/- 81 mumol/l] compared to that of normal subjects (n = 75) at rest (140 +/- 40 mumol/l). Patients with a myocardial infarction had a higher level than those with unstable angina (P less than 0.01) and non-ischaemic chest pain (n = 6) [P less than 0.05]. The levels peaked after 12-48 hours only in patients with infarction [367 +/- 140 mumol/l] (P less than 0.001) and unstable angina (273 +/- 82 mumol/l) (P less than 0.02). The levels of creatine kinase within the serum at the time of admission did not correlate well with those of blood taurine, but the peak levels of the former did correlate with the latter (P less than 0.02). Patients with known coronary arterial disease had a higher resting [236 +/- 69 mumol/l] level of blood taurine than normal subjects (P less than 0.001), which was further elevated [269 +/- 80 mumol/l] following exercise (P less than 0.001). Thus, an elevated level of taurine in whole blood at the time of admission of patients with an acute cardiac pain suggested the diagnosis of either a myocardial infarction or unstable angina. The level of taurine may be utilised to differentiate the two conditions.