Vitamin D and prognosis in acute myocardial infarction.

BACKGROUND: Vitamin D status (VDS) has been linked to mortality and incident acute myocardial infarction (AMI) in healthy cohorts. Associations with recurrent adverse cardiovascular events in those with cardiovascular disease are less clear. Our objective was to assess the prevalence and prognostic impact of VDS on patients presenting with AMI.

METHODS: We measured plasma 25-(OH)D3 and 25-(OH)D2 using isotope dilution tandem mass spectrometry, in 1259 AMI patients (908 men, mean age 65.7 ± 12.8 years). The primary endpoint was major adverse events (MACE), a composite of death (n=141), heart failure hospitalisation (n=111) and recurrent AMI (n=147) over median follow-up of 550 days (range 131-1095). Secondary endpoints were fatal and non-fatal MACE.

RESULTS: Almost 74% of the patients were vitamin D deficient (<20 ng/ml 25-(OH)D). Plasma 25-(OH)D existed mainly as 25-(OH)D3 which varied with month of recruitment. Multivariable survival Cox regression models stratified by recruitment month (adjusted for age, gender, past history of AMI/angina, hypertension, diabetes, hypercholesterolaemia, ECG ST change, Killip class, eGFR, smoking, plasma NTproBNP), showed 25-(OH)D3 quartile as an independent predictor of MACE(P<0.001) and non-fatal MACE(P<0.01), but not death. Using the lowest 25-(OH)D3 quartile(<7.3 ng/ml) as reference for MACE prediction, the 2nd, 3rd and 4th quartiles showed significantly lower hazard ratios (HR 0.59(P<0.002), 0.58(P<0.001), and 0.59(P<0.003) respectively). For non-fatal MACE prediction, the 2nd, 3rd and 4th 25-(OH)D3 quartiles were all significantly different from the lowest reference quartile (HR 0.69(P<0.05), 0.54(P<0.003) and 0.59(P<0.014) respectively).

CONCLUSIONS: VDS is prognostic for MACE (predominantly non-fatal MACE) post-AMI, with approximate 40% risk reduction for 25-(OH)D3 levels above 7.3 ng/ml.