Abstract:

Objective

To assess and compare the long-term risk of stroke in patients with acute myocardial infarction （AMI） who have preexisting versus new-onset atrial fibrillation （AF）.

Methods

Patients diagnosed with AMI and AF from 72 secondary and tertiary hospitals in Tianjin， China， between August 2016 and June 2023 were enrolled. The study population was divided into those with a prior diagnosis of AF （preexisting AF group） and those without a prior diagnosis of AF （new-onset AF group）. The primary outcomes included stroke， ischemic stroke， and hemorrhagic stroke， with secondary outcomes induding all-cause mortality， cardiovascular mortality， all bleeding and major bleeding. Multivariate Cox regression and Kaplan-Meier survival curves were used to analyze the effects of preexisting and new-onset AF on the outcomes in patients with AMI. Propensity score matching with a 1 ∶1 ratio for preexisting AF versus newonset AF was performed. Additionally， subgroup analyses and multivariable competing risk analyses were performed.

Results

A total of 5530 patients were identified， comprising 1819 with preexisting AF patients and 3711 with new-onset AF. Multivariate Cox regression showed no significant differences in the risk of stroke（HR=1.10， 95%CI: 0.98-1.23， P=0.103）， ischemic stroke （HR=1.10， 95%CI: 0.98-1.23， P=0.092）， hemorrhagic stroke （HR=0.99， 95%CI: 0.64-1.54， P=0.959）， all-cause mortality （HR=0.94， 95%CI: 0.84-1.06， P=0.342），cardiovascular mortality （HR=1.04， 95%CI: 0.89-1.21， P=0.626）， all bleeding （HR=1.03， 95%CI: 0.88-1.20，P=0.729） or major bleeding （HR=0.75， 95%CI: 0.52-1.07， P=0.115） between patients with preexisting AF and new-onset AF. After 1 ∶1 propensity score matching， 1 452 preexisting AF patients and 1452 new-onset AF patients were included. Kaplan-Meier survival curves showed that compared with preexisting AF， there was no significant difference in the risk of stroke （P=0.130）， ischemic stroke （P=0.120）， hemorrhagic stroke （P=0.560），all-cause death （P=1.000）， cardiovascular death （P=0.062）， all bleeding （P=0.220）， or major bleeding （P=0.500）in patients with new-onset AF.

Conclusion

The prognosis of patients with new-onset AF combined with AMI is comparable to those with preexisting AF and AMI. Therefore the risk of stroke， ischemic stroke，hemorrhagic stroke， death， cardiac death， all bleeding and major bleeding should be vigilantly managed in both groups.

Key words: Atrial fibrillation, Acute myocardial infarction, Stroke