Clinical predictors of patient related delay in the VIENNA ST-elevation myocardial infarction network and impact on long-term mortality

Background: While contributors to system delay in ST-elevation myocardial infarction (STEMI) are well described, predictors of patient-related delays are less clear. The aim of this study was to identify predictors that cause delayed diagnosis of STEMI in a metropolitan system of care (VIENNA STEMI network) and to investigate a possible association with long-term mortality.Methods: The study population investigated consisted of 2366 patients treated for acute STEMI in the Vienna STEMI registry from 2003–2009. Multivariable regression modelling was performed for (a) onset of pain to first medical contact (FMC) as a categorical variable (pain-to-FMC?60 min versus >60 min: ‘early presenters’ versus ‘late presenters’); and for (b) onset of pain-to-FMC (min) as a continuous variable.Results: After multivariable adjustment, female sex (odds ratio (OR) 1.348; 95% confidence interval (CI) 1.013–1.792; p=0.04) and diabetes mellitus (OR 1.355; 95% CI 1.001–1.835; p=0.05) were independently associated with late presentation in STEMI patients, whereas cardiogenic shock (OR 0.582; 95% CI 0.368–0.921; p=0.021) was a predictor of early diagnosis. When onset of pain-to-FMC was treated as a continuous variable, female sex (p=0.003), anterior infarction (p=0.004) and diabetes mellitus (p=0.035) were independently associated with longer delay, while hyperlipidaemia (p=0.002) and cardiogenic shock (p=0.017) were strong predictors of short pain-to-FMC times. Three-year-all cause mortality was 9.6% and 11.3% (p=0.289) for early and late presenters, respectively. After adjustment for clinical factors (sex, age, diabetes, current smoking, hypertension, hyperlipidaemia, cardiogenic shock and location of myocardial infarction) only a trend for increased risk of all-cause death was observed for longer pain-to-FMC times in a cox regression model (hazard ratio (HR) 1.012; 95% CI 0.999–1.025 for every 10 min of delay; p=0.061). Interestingly, early presentation within one hour of symptom onset was not associated with three-year mortality survival (HR 1.031; 95% CI 0.676–1.573; p=0.886).Conclusion: In this all-comers study of STEMI patients in the VIENNA STEMI network, cardiogenic shock was the strongest predictor of short patient-related delays, whereas a history of diabetes and female sex were independent associated with late diagnosis in STEMI. After adjustment for clinical confounders, patient related delay did not significantly impact on long-term all-cause mortality.