Serial measurement of NT-proBNP and high sensitivity C-reactive protein (hs-CRP) after an acute coronary syndrome (ACS) may help to identify patients at continuing risk of future events, although this is not currently recommended in guidelines.Methods
In patients with confirmed ACS we measured NT-proBNP and hs-CRP at 1, 3, 13 and 44 days after hospital admission to determine the proportion of patients with persistent elevation, as well as the pattern of biomarker evolution.Results
56 patients were enrolled. Median age was 66.5 years, 73% were male and 39% had a discharge diagnosis of ST elevation myocardial infarction (MI). NT-proBNP peaked at day 1 (median 1040 pg/mL) and declined over time to 448 pg/mL at day 44 (p=0.002 compared to baseline), at which point 54% had elevated levels above the reference range (figure 1). At day 44 NT-proBNP levels were correlated with age (p=0.002), ST elevation (p=0.0003) and GRACE score (p=0.0002). hs-CRP rose from median 22 mg/L at day one to a peak of 2Sg/L at day 3, then declined to 6 mg/L at day 44 (p=0.0006 compared to baseline: figure 2). At day 44 hs-CRP levels were >2 mg/L in 77% and >10 mg/L in 34% of patients and were correlated with age (p=0.014) and GRACE score (p=0.01), but not ST elevation (p=0.4). There were no deaths or recurrent MI during follow up.Conclusions
We have demonstrated that although NT-proBNP and hs-CRP decline over time after ACS, more than half of patients have persistent elevation at 44 days after ACS. This may identify a group of patients at higher risk of future adverse cardiac events.