The relative impact of components of high residual risk on the long-term prognosis after AMI

Background: The reduction in long-term mortality after acute myocardial infarction (AMI) is less pronounced than that of in-hospital mortality among patients with AMI complicated by heart failure (HF) and/or in those with a high residual thrombotic risk (HTR).

Aim: To investigate the relative prognostic significance of HTR and HF in AMI survivors.

Methods: This retrospective cohort study enrolled patients admitted for AMI in 2014-2015 in all Italian hospitals. HTR was defined as at least one of the following conditions: previous AMI, ischemic stroke or other vascular disease, type 2 diabetes, renal failure. Patients were classified into four categories: uncomplicated AMI; AMI with HTR; AMI with HF and AMI with both HTR and HF (HTR + HF). Cox proportional hazard model was used to evaluate the impact of HTR, HF and HTR + HF on the 5-year prognosis. A time-varying coefficient analysis was performed to estimate the 5-year trend of HR for major averse cardiac and cerebrovascular events (MACCE).

Results: a total of 174.869 AMI events were identified. The adjusted 5-year HR for MACCE was 1.74 (p < 0.0001) and 1.75 (p < 0.0001) in HTR and HF patients vs uncomplicated patients, respectively. The coexistence of HTR and HF furtherly increased the risk of MACCE (HR = 2.43, p < 0.0001) over the first 3 years after AMI.

Conclusion: Either HRT and HF confer an increased 5-year hazard of MACCE after AMI. The coexistence of HTR and HF doubled the overall 5-year risk of MACCE after AMI.