Elevated homocysteine levels are associated with increased ischemic myocardial injury in acute coronary syndromes.
OBJECTIVE
This study was conducted to determine whether the amount of myocardial damage during acute coronary syndromes (ACS) is related to the admission plasma homocysteine concentration.


BACKGROUND
Elevated homocysteine levels are associated with increased thrombosis in patients presenting with ACS. It is not known whether this association is reflected in the degree of myocardial injury in those patients.


METHODS
We studied consecutive patients presenting with acute myocardial infarction (MI) (n = 205) and unstable angina pectoris (UAP) (n = 185). Plasma samples were collected on admission and prior to clinical intervention and were assayed for homocysteine by high performance liquid chromatography (HPLC). Myocardial necrosis was assessed by measurements of cardiac troponin T (cTnT) on admission and 12 h after admission (peak cTnT). The patients were studied by quintiles of homocysteine concentration.


RESULTS
There was a significant increase in peak cTnT in the 5th homocysteine quintile in MI (analysis of variance [ANOVA], p = 0.005), the levels being 4.10, 3.86, 4.13, 6.20 and 7.85 microg/liter for quintiles 1 to 5, respectively (p < 0.0001, for top vs. bottom quintile). Similarly, there was a step-up in peak cTnT levels in the top homocysteine quintile in UAP (ANOVA, p < 0.0001), the levels being 0.03, 0.03, 0.02, 0.04 and 0.15 microg/liter, (p < 0.0001 for top vs. bottom quintile). In a multivariate regression model, the association between peak cTnT and the top homocysteine quintile remained strong after adjustment of other confounders including age, gender, final diagnosis and thrombolysis treatment (odds ratio [OR]: 2.92 (1.75-4.87) p < 0.0001). The patients with UAP were further examined according to peak cTnT levels below (cTnT negative) or above (cTnT positive) 0.1 microg/liter. Homocysteine levels were significantly higher in cTnT positive than cTnT negative patients; 13.8 (11.7-15.3) vs. 10.3 (9.4-11.3) micromol/liter, respectively, p = 0.002.


CONCLUSIONS
Elevated homocysteine levels are associated with a higher risk of ischemic myocardial injury in patients presenting with ACS.
Al-Obaidi
M K
MK
National Heart and Lung Institute, Cardiology Department, Charing Cross Campus, Imperial College School of Medicine, London, United Kingdom. m.al-obaidi@rbh.nthames.nhs.uk
Stubbs
P J
PJ
Collinson
P
P
Conroy
R
R
Graham
I
I
Noble
M I
MI
D000789:Angina, Unstable / Q000097:blood* / Q000000981:diagnostic imaging; D001219:Aspartate Aminotransferases / Q000097:blood; D015415:Biomarkers / Q000097:blood; D002851:Chromatography, High Pressure Liquid; D017023:Coronary Angiography; D003402:Creatine Kinase / Q000097:blood; D004562:Electrocardiography; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D006884:Hydroxybutyrate Dehydrogenase / Q000097:blood; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000000981:diagnostic imaging; D009206:Myocardium / Q000378:metabolism*; D011379:Prognosis; D012189:Retrospective Studies; D012720:Severity of Illness Index; D020107:Troponin T / Q000097:blood
D015415:Biomarkers; D020107:Troponin T; D006710:Homocysteine; D006884:Hydroxybutyrate Dehydrogenase; D001219:Aspartate Aminotransferases; D003402:Creatine Kinase