Prognostic significance of 1-year versus baseline high-sensitivity C-reactive protein after acute myocardial infarction: nationwide landmark results

Background/Aims: Residual inflammatory risk after acute myocardial infarction (AMI) remains an important determinant of long-term outcomes despite optimal lipid-lowering therapy. The prognostic significance of serial high-sensitivity C-reactive protein (hs-CRP) measurements beyond the acute phase remains unclear. This study compared baseline and 1-year hs-CRP for predicting 3-year major adverse cardiovascular events in patients with AMI undergoing percutaneous coronary intervention.Methods: We analyzed a large prospective AMI registry in which hs-CRP was measured at baseline and 1 year, classifying patients at each time point using a ≥ 2 mg/L threshold. The primary endpoint was 3-year MACE, including cardiovascular death, recurrent myocardial infarction, stroke, repeat revascularization, and stent thrombosis.Results: Among 16,371 patients, 9,618 (58.8%) had elevated hs-CRP at baseline. Of the 5,389 patients with 1-year data, 28.9% had elevated hs-CRP. Baseline hs-CRP predicted MACE within the first year (hazard ratio [HR] 1.38, 95% CI 1.21–1.57); however, this association was no longer significant beyond 1 year. One year hs-CRP independently predicted subsequent 2-year MACE (HR 1.33, 95% CI 1.01–1.77). Patients with persistently high hs-CRP (≥ 2 mg/L at both time points) had the highest 3-year MACE risk (HR 1.49, 95% CI 1.08–2.06, <i>p</i> = 0.015 vs. persistently low group) than patients with recovered, worsening, and persistently low hs-CRP.Conclusions: In patients with AMI, hs-CRP measured at 1-year provides stronger long-term prognostic information than that at baseline beyond 1 year. Routine assessment of hs-CRP may improve risk stratification and guide targeted anti-inflammatory strategies in secondary prevention.