Worse long-term prognosis in myocardial infarction occurring at weekends or public holidays with insight into myocardial infarction with nonobstructive coronary arteries.

ABSTRACT

INTRODUCTION: The weekend effect in Polish patients with myocardial infarction (MI) treated in the current network of catheterization laboratories is poorly understood. OBJECTIVES: We sought to investigate long­term prognosis of patients with MI admitted at weekends or public holidays (NWDs) and on working days (WDs). PATIENTS AND METHODS: We enrolled 865 patients with MI hospitalized between 2012 and 2017. The long­term mortality within the median (IQR) time of 68.5 (36.7-78.4) months was determined in 223 patients (25.8%) admitted on NWDs and in 642 (74.2%) on WDs. RESULTS: Patients admitted on NWDs more often had ST­segment elevation MI (41.3% vs 30.8%; P = 0.005), left anterior descending artery as an infarct­related artery (38.1% vs 30.2%; P = 0.031) and incomplete reperfusion expressed as Thrombolysis in Myocardial Infarction flow grade 0/1 following primary angioplasty (6.8% vs 1.6%; P <0.001) as compared with those hospitalized on WDs. Myocardial infarction with nonobstructive coronary arteries (MINOCA) occurred less often on NWDs (4% vs 9%, P = 0.019). The all­cause long­term mortality was higher in NWD patients as compared with those admitted on WDs (36.3% vs 28.4%; P = 0.037). By the Cox proportional hazards model with time­dependent covariates, MI on NWDs (hazard ratio, 1.027; 95% CI, 1.022-1.032; P <0.001) but not MINOCA (hazard ratio, 0.971; 95% CI, 0.595-1.583; P = 0.91) was independently associated with long­term mortality. CONCLUSIONS: Patients hospitalized on NWDs as compared with those admitted on WDs had a larger ischemic territory and more often had transmural MI with incomplete epicardial reperfusion, which resulted in a higher long­term mortality. The latter outcome was not influenced by MINOCA.