Elevation of plasma homocysteine levels associated with acute myocardial infarction.

OBJECTIVE To study the effect of acute myocardial infarction (AMI) on plasma homocystein (Hcy) levels, to determine the optimal time to measure this risk factor for coronary artery disease. DESIGN A prospective case study. SETTING The Division of Cardiac Sciences, Grey Nuns Hospital in Edmonton. PATIENTS Sixty-two patients (40 men, 22 women) admitted to hospital with AMI. INTERVENTION Measurement of Hcy levels within 48 to 72 hours of admission and at 6 weeks after discharge from the Coronary Care Unit. In a second group of 15 patients, the Hcy levels were measured on hospital days 1 and 3. MAIN OUTCOME MEASURE Comparison of the Hcy levels measured at the time of AMI and after discharge. RESULTS Mean (and standard error of the mean) Hcy level measured during the AMI (13.6 [0.98] micromol/L) was significantly higher (p < 0.05) than at 6 weeks (12.1 [1.01] micromol/L). Based on the 48- to 72-hour and 6-week determinations, 31 and 21 patients, respectively, had abnormal Hcy levels (greater than 12 micromol/L) (p < 0.001). In the separate group of 15 patients, the Hcy level measured on day 3 (9.7 [0.6] micromol/L) was noted to be significantly higher (p < 0.01) than on day 1 (7.7 [0.8] micromol/L). CONCLUSIONS There is an elevation of Hcy during AMI that may be related to an increase in the acute-phase reactant proteins. Thus, Hcy measurement should be deferred for 6 weeks in order to determine the true baseline level.