Exploring variation in timely reperfusion treatment in ST-segment elevation myocardial infarction in Norway: a national register-based cohort study

Objectives This study aimed to investigate determinants of reperfusion within recommended time limits (timely reperfusion) for ST-segment elevation myocardial infarction patients, exploring the impact of geography, patient characteristics and socio-economy.Design National register-based cohort study.Setting Multilevel logistic regression models were applied to examine the associations between timely reperfusion and residency in hospital referral areas and municipalities, patient characteristics, and socio-economy.Participants 7607 Norwegian ST-segment elevation myocardial infarction patients registered in the Norwegian Registry of Myocardial Infarction during 2015-2018.Main outcome measures The odds of timely reperfusion by primary percutaneous coronary intervention (PCI) or fibrinolysis.Results Among 7607 ST-segment elevation myocardial infarction patients in Norway, 56% received timely reperfusion. The Norwegian goal is 85%. While 81% of the patients living in the Oslo hospital referral area received timely reperfusion, only 13% of the patients living in Finnmark did so. Patients aged 75-84 years had lower odds of timely reperfusion than patients below 55 years of age (OR 0.73, 95% CI 0.61 to 0.87). Patients with moderate or high comorbidity had lower odds than patients without (OR 0.81, 95% CI 0.68 to 0.95 and OR 0.61, 95% CI 0.44 to 0.84). More than 2 hours from symptom onset to first medical contact gave lower odds than less than 30 min (OR 0.63, 95% CI 0.54 to 0.72). 1-2 hours of travel time to a PCI centre (OR 0.39, 95% CI 0.31 to 0.49) and more than 2 hours (OR 0.22, 95% CI 0.16 to 0.30) gave substantially lower odds than less than 1 hour of travel time.Results Among 7607 ST-segment elevation myocardial infarction patients in Norway, 56% received timely reperfusion. The Norwegian goal is 85%. While 81% of the patients living in the Oslo hospital referral area received timely reperfusion, only 13% of the patients living in Finnmark did so. Patients aged 75-84 years had lower odds of timely reperfusion than patients below 55 years of age (OR 0.73, 95% CI 0.61 to 0.87). Patients with moderate or high comorbidity had lower odds than patients without (OR 0.81, 95% CI 0.68 to 0.95 and OR 0.61, 95% CI 0.44 to 0.84). More than 2 hours from symptom onset to first medical contact gave lower odds than less than 30 min (OR 0.63, 95% CI 0.54 to 0.72). 1-2 hours of travel time to a PCI centre (OR 0.39, 95% CI 0.31 to 0.49) and more than 2 hours (OR 0.22, 95% CI 0.16 to 0.30) gave substantially lower odds than less than 1 hour of travel time.Conclusions The varying proportion of patients receiving timely reperfusion across hospital referral areas implies inequity in fundamental healthcare services, not compatible with established Norwegian health policy. The importance of travel time to PCI centre points at the expanded use of prehospital pharmacoinvasive strategy to obtain the goals of timely reperfusion in Norway.