Homocysteine and outcome in young patients with acute coronary syndromes.

BACKGROUND: Despite the well-known pro-thrombotic and pro-inflammatory plasma homocysteine effects, it remains uncertain whether these effects can be associated with an adverse cardiac outcome in young patients admitted with acute coronary syndromes. METHODS: Homocysteine levels were determined within 24 h after admission in 244 consecutive patients aged less than 56 years who presented with an acute coronary syndrome. We evaluated the relationship between homocysteine and both short-term (death, myocardial [re]infarction), and long-term prognosis (death, recurrent acute coronary syndrome and/or ischemic stroke), after 3.4+/-1.7 years of follow-up. RESULTS: Homocysteine levels were similar in patients both with and without in-hospital event: 8.65 (5.36-10.48) vs. 8.98 (7.38-11.13) micromol/l, p=NS. However, patients who presented with the combined event during follow-up had higher homocysteine levels than those free of the event: 10.54 (7.90-11.76) micromol/l vs. 8.52 (7.11-10.23) micromol/l, p=0.001. Patients who either died (13.78 vs. 8.87 micromol/l, p=0.012) or had a myocardial infarction (10.75 vs. 8.76 micromol/l, p=0.006) or unstable angina (10.46 vs. 8.76, p=0.006) during follow-up had higher homocysteine levels. According to the Cox regression analysis: age [hazard ratio 1.05, CI 95%, 0.99-1.10], left ventricular ejection fraction < or =40% [hazard ratio 1.93, CI 95%, 0.98-3.79], and homocysteine tertile 3 [hazard ratio 2.05, CI 95%, 1.13-3.71] were the significant determinants of the combined adverse event during follow-up. Although 41 (18%) of patients presented the TT genotype of the methylen-tetrahydrofolate-reductase thermolabile variant mutation, its occurrence had a neutral effect on morbid-mortality. CONCLUSIONS: High homocysteine levels at admission strongly predict late cardiac events in young patients with acute coronary syndromes.