Sterling MR, et al. - Researchers compared how N-terminal pro B-type peptide (NT-proBNP) effected risk of incident typical myocardial infarction (MI) and microsize MI in the REasons for Geographic and Racial Differences in Stroke (REGARDS) Study. NT-proBNP was shown to be related to all MIs, but was a particularly strong risk factor for microsize than typical MI.

Methods

• Researchers performed a national cohort study (the REGARDS Study) recruiting 30,239 U.S. community-dwelling black and white adults aged ≥ 45 years between 2003 to 2007.
• Incident typical MI (definite/probable MI with peak troponin ≥ 0.5 μg/L), incident microsize MI (definite/probable MI with peak troponin) and incident fatal coronary heart disease (CHD) were included as outcomes.
• They estimated the hazard ratio of the outcomes as a function of baseline NT-proBNP using a case-cohort design.
• They also used competing risk analyses to investigate if the associations of NT-proBNP differed between the risk of incident microsize MI and incident typical MI, as well as if the association of NT-proBNP differed between incident non-fatal microsize MI and incident non-fatal typical MI, while accounting for incident fatal CHD and heart failure (HF).

Results

• Researchers reported 315 typical MI, 139 microsize MI, and 195 incident fatal CHD over the median follow-up of 5 years.
• NT-proBNP was found to be independently and strongly related to all CHD endpoints.
• For incident microsize MI, significantly greater risk was observed, even after removing those with suspected HF prior to or coincident with their incident CHD event.