ABC | Volume 112, Nº4, April 2019

Original Article Balk et al Transfer time in STEMI patients Arq Bras Cardiol. 2019; 112(4):402-407 Subjects Patients with diagnosis of STEMI registered in the database of the Institute of Cardiology of the University Foundation of Cardiology (IC-FUC) were assessed and allocated to one of two groups – Group A, patients whose names and electrocardiographic results were listed in the electronic mailbox of the emergency department, confirming the approximate time of contact and indicating the place of origin – and Group B, self-referred patients (all others). Transfer time (min) was calculated by subtracting the time and the day the message (containing ECG result attached) was received from the time and day patients were admitted to the emergency department (according to medical records). Ethical consideration The study was registered at the research unit of the IC-FUC and approved by the local ethics committee. Statistical analysis Continuous variables were expressed as mean ± standard deviation or median and interquartile range, as appropriate. Categorical variables were presented as absolute number and percentage and compared by the chi-square test and Z-test. Continuous variables were analyzed using Student’s t-test for independent samples or the Wilcoxon-Mann-Whitney test, as appropriate. Normality was tested by the D'Agostino-Pearson test. Our database was constructed using Microsoft Excel 2010 software and then transferred to the IBM Statistical Package for the Social Sciences (SPSS) version 19.0.0. The SPSS software version 18.0 was used for statistical analysis. Two-tailed p-values < 0.05 were considered statistically significant. Results E-mail messages received by the emergency department of the IC-FUC between April 2014 and September 2015 were reviewed. ECG results showing ST-segment elevation and identification data of patients were cross-checked with data registered in the AMI database of the hospital. During the study period, 2,532 pieces of information were excluded – 68 messages in which patients’ names could not be identified, 869 ECG results of patients with non-STEMI, 381 duplicate messages, 23 “unknown hard error” messages, 491 tomography reports, 408 internal messages, and 292 ECG results of patients with STEMI that had not been referred from other hospitals or patients not registered in the AMI database. Final sample was composed of 621 patients, 215 transferred patients (group A) and 406 self-referred (group B). Table 1 describes characteristics of groups A and B. Both groups had similar risk factors. Figure 1 depicts mean variation in the time elapsed from symptomonset to arrival at emergency department (delta T) and the travel distance of patients, depending on the place of origin. Mean delta T of all patients was 334 minutes. Mean delta T of patients transferred by emergency medical services of the Secretariat of Health (group A) was 385 minutes, with a delay in transfer time of 147 minutes. Mean delta T of group B was 307 minutes (Figure 2). Figure 3 shows a scatter plot of delta T and travel distance, with a good correlation coefficient between these variables (R = 0.55 and p < 0.001). Despite that, the graphs shows a number of cities with shorter travel distances but higher transfer times (plots above diagonal), and cities with longer travel distances but shorter transfer time (plots below diagonal). Despite the statistical difference in transfer time, no difference in mortality was observed between the groups. Discussion Treatment of STEMI is considered a medical emergency, with significant mortality even in well renowned centers. 11 The main objective of the therapy is restoration of blood flow in the culprit vessel. This is achieved by administration of fibrinolytic agents to dissolve intracoronary thrombus, or by PTCA, with percutaneous recanalization of the infarct artery with or without stent implantation. In the present study, we demonstrated the difference in delta T between STEMI patients referred for PTCA and self-referred STEMI patients to the emergency department of the IC-FUC The finding that transferred patients have longer ischemia time and a longer time to coronary reperfusion therapy is not a surprise, since in these cases there are delays in contacting Table 1 – Characteristics of patients referred from other hospitals (group A) and self-referred patients (group B). Porto Alegre, RS, Brazil Variable Group A (n = 215) Group B (n = 406) p Age, years* 58 (28-87) 60 (18-98) 0.50 Male sex† 145 (67) 283 (69) 0.67 Risk factors† Hypertension 128 (59) 251 (61) 0.69 Smoking 148 (68) 249 (61) 0.10 Dyslipidemia 67 (31) 132 (32) 0.86 Diabetes 55 (25) 96 (23) 0.64 Family history 45 (20) 109 (26) 0.11 * Data presented as median and interquartile range; † Absolute and relative frequency. 403