Homocysteine and outcome in young patients with acute coronary syndromes

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.

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.

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.

High homocysteine levels at admission strongly predict late cardiac events in young patients with acute coronary syndromes.