Holotranscobalamin and methylmalonic acid as prognostic markers following an acute myocardial infarction

Abstract

Objective: To evaluate whether low levels of holotranscobalamin (holoTC) or elevated levels of methylmalonic acid (MMA), both indicators of vitamin B12 deficiency, might predispose to new cardiovascular events following an acute myocardial infarction (MI). Design: A prospective prognostic study. Setting: One hospital center in Stavanger, Norway. Subjects: A total of 300 patients admitted with an acute MI. Methods: Registration of new TnT positive coronary events (defined as TnT>0.05 μg/l and a typical MI pattern) and/or cardiac death during a median follow-up time of 45 months. Results: We compared the recurrence of events in the lowest quartile of holoTC (Q1<73.9 pmol/l) to the event rate above the 25% percentile (Q2-4). For methylmalonic acid (MMA) the same comparison was carried out for the upper quartile (Q4≥0.24 μmol/l) as compared with the event rate below the 75% percentile (Q1-3). After 18 and 45 months of follow-up, the odds ratio (OR) for Q1 vs Q2-4 for holoTC was 1.15 (95% confidence interval (CI) 0.91-1.46, P=0.25) and 1.05 (95% CI 0.86-1.29, P=0.64), respectively. For MMA the OR for Q4 vs Q1-3 was 0.95 (95% CI 0.76-1.19, P=0.67) after 18 months and 1.01 (95% CI 0.83-1.23, P=0.90) after 45 months. Conclusion: This study showed no increased risk of future cardiovascular events associated with low levels of holoTC or high levels of MMA following an acute MI.