Objective To investigate the dynamic changes of cardiomyocyte apoptosis and the role of death receptor apoptotic pathway in a rat model of coronary microembolization (CME).Methods Adult rats were randomized to coronary microembolization (CME group,n = 63) or sham-operated group (S group,n = 55).CME model was established by aortic injection of 0.1 ml microspheres(42 μm,3×10~4/ml)into the left ventricle when the ascending aorta was temporarily clamped.S group received 0.1 ml saline injection and survived rats were randomly examined at 0,3,6,12 and 24 hour post CME (n = 10 each).Heart function was evaluated by echocardiography.Myoeardium sample was stained with hematoxylin-eosin and hematoxylin-basic fuchsin-picric acid to detect infarct areas.Cardiomyocyte apoptosis was detected with TUNEL staining.The expression of caspase-3 and caspase-8 was measured by Western blot analysis.Results Compared with S group,the left ventricular ejection fraction was significantly decreased and left ventricular end-diastolic diameter was significantly increased in CME group (all P＜0.05) except 0 hour CME group.The infarct sizes were similar in 3 hour,6 hour,12 hour,and 24 hour CME groups (P＞0.05).The apoptosis index (AI) in CME group were significantly higher at each time point compared to S group (P ＜0.05) except 0 hour CME group and peaked at 6 hours.Apoptotic cardiomyocytes were found mainly in the myocardial microinfarcted area and border zones.The relative expression of caspase-3 and caspase-8 in CME group were both significantly increased at 3 hours and peaked at 6 hour post CME (P ＜0.05).Conclusion Cardiomyocytes apoptosis was significantly increased after coronary microembolization via activating death receptor apoptotic pathway in this coronary microembolization model.

BACKGROUND: Patients with atrial fibrillation (AF) and prior stroke history have a high risk of cardiovascular events despite anticoagulation therapy. It is unclear whether catheter ablation (CA) has further benefits in these patients. METHODS: AF patients with a previous history of stroke or systemic embolism (SE) from the prospective Chinese Atrial Fibrillation Registry study between August 2011 and December 2020 were included in the analysis. Patients were matched in a 1:1 ratio to CA or medical treatment (MT) based on propensity score. The primary outcome was a composite of all-cause death or ischemic stroke (IS)/SE. RESULTS: During a total of 4.1 ± 2.3 years of follow-up, the primary outcome occurred in 111 patients in the CA group (3.3 per 100 person-years) and in 229 patients in the MT group (5.7 per 100 person-years). The CA group had a lower risk of the primary outcome compared to the MT group [hazard ratio (HR) = 0.59, 95% CI: 0.47-0.74, P < 0.001]. There was a significant decreasing risk of all-cause mortality (HR = 0.43, 95% CI: 0.31-0.61, P < 0.001), IS/SE (HR = 0.73, 95% CI: 0.54-0.97, P = 0.033), cardiovascular mortality (HR = 0.32, 95% CI: 0.19-0.54, P < 0.001) and AF recurrence (HR = 0.33, 95% CI: 0.30-0.37, P < 0.001) in the CA group compared to that in the MT group. Sensitivity analysis generated consistent results when adjusting for time-dependent usage of anticoagulants. CONCLUSIONS In AF patients with a prior stroke history, CA was associated with a lower combined risk of all-cause death or IS/SE. Further clinical trials are warranted to confirm the benefits of CA in these patients.