ORIGINAL RESEARCH published: 25 April 2022 doi: 10.3389/fcvm.2022.847982 Socioeconomic Status and Prognosis of Patients With ST-Elevation Myocardial Infarction Managed by the Emergency-Intervention “Codi IAM” Network Helena Tizón-Marcos 1,2,3,4*, Beatriz Vaquerizo 1,2,3,4,5 , Josepa Mauri Ferré 6,7 , Núria Farré 1,2,3,4,5 , Rosa-Maria Lidón 4,8 , Joan Garcia-Picart 9 , Ander Regueiro 10 , Albert Ariza 11 , Xavier Carrillo 6 , Xavier Duran 3,12 , Paul Poirier 13 , Mercè Cladellas 1,2,3,5 , Edited by: Anna Camps-Vilaró 3,4 , Núria Ribas 1,2,3,5 , Hector Cubero-Gallego 1,2,3 and Jaume Marrugat 3,4 Pietro Amedeo Modesti, 1 Hospital del Mar, Servicio de Cardiología, Barcelona, Spain, 2 Grupo de Investigación Biomédica en Enfermedades del University of Florence, Italy Corazón, Barcelona, Spain, 3 IMIM (Instituto Hospital del Mar de Investigaciones Médicas), Barcelona, Spain, 4 Centro de Reviewed by: Investigación Biomédica en Red Enfermedades Cardiovasculares, Instituto de Salud Carlos III (ISCIII), Madrid, Spain, Jun Lyu, 5 Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain, 6 Hospital Universitari GermansTrias I. Pujol, First Affiliated Hospital of Jinan Servicio de Cardiología, Badalona, Spain, 7 Departament de Salut, Generalitat de Catalunya, Barcelona, Spain, 8 Hospital University, China Universitari de la Valld’Hebron, Servicio de Cardiología, Barcelona, Spain, 9 Hospital de la Santa Creu I. Sant Pau, Servicio de Tiny Nair, Cardiología, Barcelona, Spain, 10 Hospital Clínic i Provincial, Servicio de Cardiología, Barcelona, Spain, 11 Hospital PRS Hospital, India Universitario de Bellvitge, Servicio de Cardiología, L’Hospitalet de Llobregat, Barcelona, Spain, 12 AMIB, Assessoria *Correspondence: Metodològica i Bioestadística, Barcelona, Spain, 13 Insititut Universitaire de Cardiologie et Pneumologie de Québec, Québec, Helena Tizón-Marcos QC, Canada htizon@psmar.cat Background: Despite the spread of ST-elevation myocardial infarction (STEMI) Specialty section: This article was submitted to emergency intervention networks, inequalities in healthcare access still have a negative Cardiovascular Epidemiology and impact on cardiovascular prognosis. The Family Income Ratio of Barcelona (FIRB) is a Prevention, a section of the journal socioeconomic status (SES) indicator that is annually calculated. Our aim was to evaluate Frontiers in Cardiovascular Medicine whether SES had an effect on mortality and complications in patients managed by the Received: 03 January 2022 “Codi IAM” network in Barcelona. Accepted: 18 March 2022 Published: 25 April 2022 Methods: This is a cohort study with 3,322 consecutive patients with STEMI treated Citation: in Barcelona from 2010 to 2016. Collected data include treatment delays, clinical and Tizón-Marcos H, Vaquerizo B, risk factor characteristics, and SES. The patients were assigned to three SES groups Ferré JM, Farré N, Lidón R-M, according to FIRB score. A logistic regression analysis was conducted to estimate the Garcia-Picart J, Regueiro A, Ariza A, Carrillo X, Duran X, Poirier P, adjusted effect of SES on 30-day mortality, 30-day composite cardiovascular end point, Cladellas M, Camps-Vilaró A, Ribas N, and 1-year mortality. Cubero-Gallego H and Marrugat J (2022) Socioeconomic Status and Results: The mean age of the patients was 65 ± 13% years, 25% were women, and Prognosis of Patients With 21% had diabetes mellitus. Patients with low SES were younger, more often hypertensive, ST-Elevation Myocardial Infarction Managed by the diabetic, dyslipidemic (p < 0.003), had longer reperfusion delays (p < 0.03) compared to Emergency-Intervention “Codi IAM” participants with higher SES. Low SES was not independently associated with 30-day Network. Front. Cardiovasc. Med. 9:847982. mortality (OR: 0.95;9 5% CI: 0.7–1.3), 30-day cardiovascular composite end point (OR: doi: 10.3389/fcvm.2022.847982 1.03; 95% CI: 0.84–1.26), or 1-year all-cause mortality (HR: 1.09; 95% CI: 0.76–1.56). Frontiers in Cardiovascular Medicine | www.frontiersin.org 1 April 2022 | Volume 9 | Article 847982 Tizón-Marcos et al. STEMI Network and Socioeconomic Status Conclusion: Although the low-SES patients with STEMI in Barcelona city were younger, had worse clinical profiles, and had longer revascularization delays, their 30-day and 1-year outcomes were comparable to those of the higher-SES patients. Keywords: ST-elevation myocardial infarction, reperfusion, primary percutaneous coronary intervention, mortality, inequalities INTRODUCTION addition, cardiac arrest or patients who died with an initial electrocardiogram showing ST-segment elevation or patients Ischaemic heart disease is the leading component of with a new left bundle-branch block. Barcelona patients were cardiovascular disease (CVD), which is the first cause of treated in other facilities outside Barcelona and non-residents mortality and morbidity worldwide (1, 2). Loss in quality-of-life were excluded. and mortality due to cardiovascular disease has globally declined The “Codi IAM” STEMI emergency management network because of the implementation of evidence-based treatments and was launched in 2010 in a region of 7.6 million inhabitants. The early and efficient management of acute coronary syndromes three main objectives of the network were (i) to increase the (ACSs), as well as appropriate drugs for secondary prevention rate of reperfusion therapy among patients with STEMI, (ii) to and cardiac rehabilitation (3). Improvements in morbidity and achieve primary percutaneous coronary intervention (PPCI) in survival after an ACS have spread unevenly throughout world less than 120 min from the first contact with the health system regions, and they are more developed and implemented often (3), and (iii) to monitor the results of the network with a registry. in high-income countries (4). These differences may be partially The city of Barcelona was the first to be completely covered by explained by varying ACS emergency management modalities the network because of its high-density population. Three PPCI and population epidemiologic settings, including the influence hospitals that are open 24 h/7 days a week and one hospital of socioeconomic status (SES). with daytime PPCI cover the city’s STEMI management needs. Multiple studies have shown that SES, measured by education Updated operating details of the network have been recently level, occupation, or income, is associated with cardiovascular published by our group (11). Basically, an emergency medical risk factors and outcomes after acute myocardial infarction service (EMS) is responsible for detecting patients with STEMI (5–7). Even in high-income countries, poor socioeconomic and coordinates facilities (EMS ambulances and helicopters, with circumstances may limit access to and increase delays in PPCI hospitals). revascularization procedures, resulting in larger infarct size, ST-elevation myocardial infarction was defined according lower compliance to secondary prevention drugs, and in general, to current guidelines (3). Fibrinolysis was only considered if poor application of and compliance with specialized state-of-the- expected delays in PPCI treatment were not acceptable and there art cardiac treatments (8, 9). were no contraindications. Percutaneous coronary intervention Implementation of coordinated and standardized treatment (PCI) post-fibrinolysis was initially only considered in the networks for acute ST-elevation myocardial infarction (STEMI) absence of effective reperfusion. The local health system provides increases detection, decreases treatment times, and increases universal health coverage; in addition, it provides a partial survival in all kinds of socioeconomic environments (6, 10). subsidy for medication costs depending on patients’ income and The aim of this study was to analyze whether low SES working status. determines more 30-day complications and 1-year all-cause The registry of the “Codi IAM” activity started in 2010 mortality in patients with STEMI managed by the “Codi Infart and includes demographic, clinical, therapeutic, and discharge Agut de Miocardi amb Elevació ST (Codi IAM)” emergency data collected in an electronic form from patients with STEMI STEMI care network in Barcelona in a contemporary cohort from occurring within the previous 12 h. Epicardial coronary flow in a European southern city. the culprit STEMI artery is graded according to Thrombolysis in Myocardial Infarction (TIMI) flow grade (12), and reperfusion is MATERIALS AND METHODS considered optimal when TIMI 3 flow is obtained in the culprit lesion. Data collection was extended to new variables in 2012 Population (acute pulmonary edema, number of diseased vessels, and TIMI In this retrospective cohort study, we included patients from flow) and in 2015 (hypertension, dyslipidemia, smoking status, the registry of the “Codi IAM” emergency management previous stroke, previous treatment, and type and number of network diagnosed with STEMI from 2010 to 2016 who stents). Bleeding was included only in cases requiring transfusion. were residents of Barcelona. The registry includes, in The Family Income Ratio of Barcelona (FIRB) is an indicator of the mean income ratio of inhabitants of the 73 districts Abbreviations: ACS, Acute coronary syndrome; BMS, bare-metal stent; CHD, in Barcelona city and shows imbalances relative to the mean coronary heart disease; DES, drug-eluting stent; ECG, electrocardiogram; EMS, value of the city, which is set at 100. The FIRB has been emergency medical system; FIRB, Family Income Ratio of Barcelona; OSs, onset of symptoms; PCI, percutaneous coronary intervention; PPCI, primary calculated annually since 2007 by the Technical Office of the percutaneous coronary intervention; SES, socioeconomic status; STEMI, ST- Barcelona City Council, and it can be accessed online (13). elevation myocardial infarction; TIMI, thrombolysis in myocardial infarction. This indicator combines five concepts: i) ratio of university Frontiers in Cardiovascular Medicine | www.frontiersin.org 2 April 2022 | Volume 9 | Article 847982 Tizón-Marcos et al. STEMI Network and Socioeconomic Status graduates, ii) ratio of unemployed to employable inhabitants, iii) Fisher exact test, or ANOVA for categorical variables; p-tendency the number of vehicles per inhabitant, iv) engine power of new was used in all comparisons. A p-value < 0.05 was considered vehicles acquired, and v) price of second-hand housing. FIRB statistically significant. The association between SES and 30-day was assigned to patients according to their address and district death or complications was evaluated with odds ratios (ORs) affiliation, and it has been used as a surrogate of socioeconomic calculated using logistic regression models, and 1-year mortality status (SES) in this study. The patients were assigned to three SES in 30-day survivors was evaluated with hazard ratios (HRs) classes according to the FIRB classification used by the Technical using Cox proportional-hazards regression models. The models Office: low SES (low and very low SES corresponding to FIRB were adjusted considering confounding variables associated with values below 80), mid SES (mid-low and mid-high corresponding STEMI prognosis, which had < 8% missing values: age, sex, to FIRB values from 81 to 125), and high SES (high and very high diabetes mellitus, recruitment year, type of initial care, place SES corresponding to FIRB values from 126 to 159) (13). of treatment, time from electrocardiogram to PPCI, and Killip Mortality data of the patients were obtained from the National class. Kaplan Meier survival curves were fitted for the three SES Mortality Registry. The quality of the data included in the registry categories, and log-ranked p-values were used for comparison. is periodically verified by external audits. The Patients were assigned to the hospital where they spent most of their hospital stay. End Points In order to calculate 1-year mortality, the mortality of Primary assessment end points were 30-day mortality, a 30- patients admitted in 2016 was analyzed up to 2017. Analyses day composite end point including death, ventricular fibrillation, were performed using SPSS software version 24.0. This project pulmonary edema, or cardiogenic shock during admission, and was approved by the ethics committee of Hospital del Mar 1-year all-cause mortality in 30-day survivors. (2020/9056), and all data are anonymous. The project was approved by the Scientific Committee of “Codi IAM”. Procedures Statistical Analysis and data collection complied with the Declaration of Helsinki Categorical variables are shown as numbers and percentages; and Spanish data protection laws. continuous variables are shown as mean and SD or as median and interquartile range, or as specified otherwise. RESULTS Patient characteristics and treatment times were compared according to each end point. Student’s t-test or Mann-Whitney U- The distribution of patients with STEMI treated in Barcelona city test was conducted for continuous variables and Chi-squared test, according to their SES is shown in Figure 1, in Figure 1: 43.4% FIGURE 1 | “Codi IAM” ST-elevation myocardial infarction (STEMI) patient inclusion flowchart. Frontiers in Cardiovascular Medicine | www.frontiersin.org 3 April 2022 | Volume 9 | Article 847982 Tizón-Marcos et al. STEMI Network and Socioeconomic Status had low SES, 41.1% had mid SES, and 15.4% had high SES. The were higher in those patients with higher SES compared to those annual hospitalization rate of patients with STEMI is shown in with lower SES. Supplementary Material 1. The number of patients with STEMI In Table 4, we show that 30-day mortality, 30-day treated from the lowest SES was higher than the mean rate during cardiovascular complications, and 1-year mortality did not the 7 years of the study. differ between the SES groups after adjusting for confounding Patients with low SES were younger, had a higher prevalence factors. There were no significant differences in survival curves of cardiovascular risk factors, and were more often initially cared at 1-year according to SES (Figure 2). for by general practitioners (Table 1). In addition, they had a more deleterious cardiovascular risk factor profile than patients DISCUSSION with higher SES. There was no difference in Killip class at STEMI presentation by SES. Low-SES patients with STEMI treated in Barcelona by the “Codi Patients received PPCI as the first treatment in more IAM” emergency network have a higher burden of cardiovascular than 93% of the cases but with no significant differences risk factors and longer treatment delays than patients with higher according to SES. Patients with higher SES had significant SES. Despite this, they have similar mortality or cardiovascular epicardial coronary disease significantly less often than those complication rate at 30 days and similar 1-year mortality. with mid and low SES (Table 2). Patients with lower SES had Recent STEMI guidelines have emphasized the importance a tendency to be less often treated with drug-eluting stents of performing research addressing gaps in knowledge and the (DESs) than those with mid and higher SES (55.1 vs. 57.5 need for observational data and real-world evidence to ensure vs. 69%, respectively, p < 0.35). Supplementary Material 2 high-quality rapid and equal care for patients with STEMI in shows differences in patients treated with DESs vs. bare-metal geographic areas (14). Previous studies from the late 1990s stents (BMS). DESs are significantly less used in the lower and early new century showed that SES was associated with SES group; nevertheless, this difference is not greater than both short- and long-term mortalities after ACS (15) and that one unit. an inverse trend in survival after myocardial infarction was Patients with lower SES had longer delays regarding time from also observed with SES levels in district-based studies (16, symptom onset to diagnosis (first electrocardiogram) than those 17). However, these data come from heterogeneous studies, with highest SES (Table 3), and longer times from symptom different time frames and may reflect inequalities in disease onset to PPCI hospital than the mid and high SES groups. incidence, access to healthcare systems, and poor compliance Electrocardiogram-to-open-artery times showed a decreasing with secondary prevention medications (18). Moreover, different trend with SES. Longer ischemic times were observed in patients SES indicators were used in previous studies: household income with lower SES. Accordingly, ratios of PPCI in less than 120 min (14), highest educational level (15), geographical area (18), TABLE 1 | Baseline clinical characteristics according to socioeconomic status (SES) classification. All N = 3,322 Low SES ≤80 Mid SES 81–125 High SES ≥126 P-value N = 1,443 N = 1,366 N = 513 Age, years 65.3 ± 13.5 64.4 ± 13.9 65.8 ± 13.3 66.6 ± 13.0 0.002 Women,% 26.3 27.0 25.9 25.3 0.720 Smokers,%* 26.5 27.1 27.0 23.2 0.460 Hypertension,%* 40.8 43.0 41.8 30.4 0.024 Dyslipidemia,%* 32.1 35.2 31.9 22.5 0.008 Diabetes mellitus,% 20.7 23.3 20.2 14.4 <0.005 Previous stroke, %* 2.6 2.9 2.2 2.9 0.790 Oral anticoagulant,%* 1.9 2.5 1.0 2.9 0.720 Antiplatelet drugs, %* 8.0 9.6 5.9 8.7 0.280 First contact General practitioner, % 15.1 18.9 13.4 9.0 <0.012 Emergency medical system, % 47.7 49.1 44.8 51.1 Complications Mechanical ventilation, % 6.3 5.2 7.5 6.0 0.150 Ventricular fibrillation, % 7.4 6.4 8.4 7.2 0.240 Atrial fibrillation, % 1.4 1.9 1.1 0.8 0.026 AV blockade, % 4.9 4.4 5.6 4.5 0.550 Pulmonary edema, %** 2.2 1.5 3.1 1.4 0.430 Cardiogenic shock, % 6.4 5.9 6.8 6.4 0.480 AV Blockade, atrioventricular blockade. *Data since 2015, N = 991. **Data available since 2012. N = 2416. Frontiers in Cardiovascular Medicine | www.frontiersin.org 4 April 2022 | Volume 9 | Article 847982 Tizón-Marcos et al. STEMI Network and Socioeconomic Status TABLE 2 | Primary reperfusion procedure in the “Codi IAM” network during the period 2010–2016 according to SES. All N = 3,322 Low SES ≤80 Mid SES 81–125 High SES ≥126 P-value N = 1,443 N = 1,366 N = 513 Coronary angiogram without PCI, % 5.0 4.6 5.5 5.0 0.640 PPCI, % 93.4 94.2 92.7 92.5 Thrombolysis, % 0.2 0.3 0.2 0.2 0.240 Initial TIMI 0, %* 68.3 66.3 69.0 72.2 0.035 Initial TIMI 3, %* 11.0 12.1 10.2 9.6 0.120 Final TIMI 0, %* 2.1 2.2 1.6 3.0 0.630 Final TIMI 3, %* 91.6 92.1 91.5 90.6 0.390 No significant epicardial coronary disease, %* 5.3 4.3 5.5 7.6 0.023 3-vessel disease, %* 15.0 15.2 15.1 14.0 0.670 Left main disease, %* 4.2 3.9 4.2 5.2 0.300 Stents used** Only BMS use, % 40.6 43.5 39.8 28.6 Only DES use, % 57.7 55.1 57.5 69 0.353 Both BMS and DES use, % 1.93 1.45 2.65 2.38 Anterior STEMI, % 41.8 42.4 40.6 43.1 0.890 Inferior STEMI, % 43.8 42.2 45.2 44.6 0.180 Bleeding with transfusion, % 0.6 0.7 0.3 1.0 0.920 *Data available since 2012. **Data available since 2015. PPCI, Primary percutaneous coronary intervention; TIMI, thrombolysis in myocardial infarction flow; BMS, bare metal stent; DES, drug-eluting stent; STEMI, ST-elevation myocardial infarction. TABLE 3 | Delays in initial medical care, diagnosis, and revascularization according to SES during the period 2010–2016. All N = 3,322 Low SES ≤80 Mid SES 81–125 High SES ≥126 P-value N = 1,443 N = 1,366 N = 513 OS-ECG, min 82 [43–183] 85 85 [45–187] 75 0.003 [45–185] [35–166] ECG-Open Artery, min 85 [67–115] 87 83 [65–115] 81 <0.005 [69–117] [63–105] OS-Arrival to hospital, min 130 [82–240] 135 128 [80–254] 120 0.033 [85–240] [75–225] OS-Open Artery, min 184 [127–305] 190 180 [125–312] 165.5 0.003 [133–310] [118–269] PPCI <120 min from ECG, % 78.7 77.3 78.6 83.0 0.034 30-day mortality, % 7.7% 7.6% 8.3% 6.6% 0.430 30-day composite, %** 19.9% 19.4% 20.7% 19.1% 0.600 1-year mortality, %* 4.7% 5.2% 4.9% 5.1% 0.810 OS, onset of symptoms; ECG, electrocardiogram; Min, minutes, median [interquartile range]. * in 30-day survivors; ** death, pulmonary edema, cardiogenic shock, or ventricular fibrillation. racial aspects (16), and various composite indexes (17, 19– SES (22). The population analyzed in this study represents a 21). Composite indexes can include varying combinations of sample of homogeneously treated patients with STEMI: mostly household income, educational level, unemployment rate, vehicle (>93%) treated by PPCI in a public integrated medical system ownership and engine power, prices of housing, the proportion of and features the inclusion of patients not treated with PPCI. families with > 4 children, community services, environmental The use of PPCI methods in patients with STEMI varies largely conditions, and crime level. These composites indexes reflect by region and can be explained by several factors such as a multilevel stratum of social, educational, and economic data, supply factors, the number of physicians, and the number of which can give a better picture of concurring effects that available hospitalization beds for acute conditions, as well as determine health, acute and chronic treatments, and follow-up constraining measures and “patient-level” factors (10). However, compared to strictly economic information. the standardization of treatments driven by new evidence- Studies from various geographical areas have found that access based medicine and consequent guidelines allows countries with to revascularization procedures is reduced in groups with lower different income levels to progressively organize emergency Frontiers in Cardiovascular Medicine | www.frontiersin.org 5 April 2022 | Volume 9 | Article 847982 Tizón-Marcos et al. STEMI Network and Socioeconomic Status TABLE 4 | Low-SES patients with ST-elevation myocardial infarction (STEMI) adjusted odds ratio (OR) of 30-day mortality (model 1); a 30-day composite end point (death, ventricular fibrillation, acute pulmonary edema, or cardiogenic shock) (model 2); and hazard ratio (HR) of 1-year mortality in 30-day survivors (model 3) in the “Codi IAM” network during the 2010-2016 period. MODEL 1: 30-day mortality risk for STEMI patients in the whole cohort N = 3,078 OR 95% CI Low SES 0.95 0.70–1.30 MODEL 2: 30-day composite endpoint risk for STEMI patients in the whole cohort N = 3,078 OR 95% CI Low SES 1.03 0.84–1.26 MODEL 3: One-year mortality risk for STEMI patients in the whole cohort in 30-day survivors N = 2,720 HR 95% CI Low SES 1.09 0.76–1.56 Models 1 and 3 were adjusted for age, sex, diabetes mellitus, Killip III/IV vs. I/II, first medical care, coronary percutaneous intervention, hospital, year of treatment, time from electrocardiogram to coronary percutaneous intervention (>120 min), and type of initial medical care. Model 2 was adjusted for age, sex, diabetes mellitus, first medical care, coronary percutaneous intervention, hospital, year of treatment, time from electrocardiogram to coronary percutaneous intervention (>120 min), and type of initial medical care. FIGURE 2 | Cumulative survival according to socioeconomic status (SES). Global log-ranked p-values = 0.79; mid SES vs. low SES = 0.78; high SES vs. low SES = 0.49. networks for the early management of high-impact diseases in a worse cardiovascular profile, longer treatment delays, and terms of incidence, hospitalization, and case fatality such as in different access routes to the health system, which did not, STEMI (23, 24). however, translate into worsened 30-day complications or 1-year Network organization and public access to care and health mortality. Besides, when adjusting for potential confounders, SES may result in the neutralization of both higher incidence of data were not associated with either end points, suggesting that the disease and adverse clinical baseline characteristics in low a robust healthcare system may flatten socioeconomic baseline SES groups (25, 26). In our study, the low SES group had disparity potential effect. Similar findings have been described in Frontiers in Cardiovascular Medicine | www.frontiersin.org 6 April 2022 | Volume 9 | Article 847982 Tizón-Marcos et al. STEMI Network and Socioeconomic Status international cohorts in different studies performed in a single- features than citizens with higher SES. Nevertheless, the “Codi center fashion (22), in groups of hospitals within a geographical IAM” emergency network for STEMI management documented area (20, 26), or within a city (17). Those studies have in common similar 30-day complications and 1-year mortality regardless of the inclusion of patients with STEMI treated with PPCI as a SES suggesting that a robust healthy system may override baseline standard treatment within a structural public STEMI network adverse patients’ characteristics. and showed no interaction of SES with mortality. However, most of these registries reported results from cohorts of patients before DATA AVAILABILITY STATEMENT 2010. Other previous registries also included patients with other conditions such as non-ST-elevation myocardial infarction (21) The datasets presented in this article are not readily available or excluded patients treated with fibrinolysis (27). Exclusion of because the dataset belongs to Departament de Salut, Generalitat patients treated with fibrinolysis or patients who did not receive de Catalunya, and the researchers only have access to PPCI may, however, bias the results of any study aiming to clarify statistical analysis. the importance of socioeconomic factors in STEMI prognosis because of the geographical gradient toward the periphery for ETHICS STATEMENT lower-income groups and its relationship with the optimal timing of treatment for PPCI (17, 28, 29). The studies involving human participants were reviewed The lower tendency of use of DESs in the low-SES group and approved by Hospital del Mar Ethics Committee. The observed in our study has also been reported in American cohorts patients/participants provided their written informed consent to (30–32), which is a “treatment-risk paradox” in which higher-risk participate in this study. patients are not treated with optimal or evidence-based strategies, and the use of mechanical support devices is reduced, and it AUTHOR CONTRIBUTIONS may result in prognosis worsening (19, 33, 34). This finding may reflect the fact that differences in outcomes may not only be HT-M: study management, data collection, interpretation related to the use of a specific treatment/device in the acute period of collected data, and preparation of the manuscript. BV: but to a whole standardized medical approach in which access to critical revisions of the manuscript. JM: participation in study secondary prevention may be of utmost importance (35) and that management and acquisition of data and revision of the the health system may override the burden of higher risk subsets. manuscript. RL, AA, and NF: critical revisions of the manuscript Our study has several limitations. First, the data are derived and data collection. XC: revision of the manuscript and data from the first 7 years of implementation of a regional STEMI collection. JG-P, AR, MC, AC-V, XD, NR, and HC-G: revision network, and its registry has evolved over the years and includes of the manuscript. PP: extensive revision of the manuscript. JM: progressively more detailed data such as treated hypertension, study management, interpretation of collected data, statistical treated dyslipidemia, smoking status, previous stroke, number analysis, and extensive revision of the manuscript. and type of stents, and LV function. Moreover, there were no available records on the medical treatment administered FUNDING during the index admission, at discharge, and/or regarding other therapies during follow-up such as cardiovascular rehabilitation. This project was supported by the CIBERCV of research on These treatments as well as the patients’ adherence to cardiovascular diseases personnel hired with its resources. prescriptions have been shown to have a direct impact on mortality (35, 36) and may also be related to socioeconomic ACKNOWLEDGMENTS conditions (21). Finally, the FIRB is a composite index that aggregates data from all inhabitants of a given district, so it does We would like to thank Isaac Aparicio Verdoy and Marius not allow analyzing effects of individual-level SES. However, the Boada from Oficina Municipal de Dades, Ajuntament FIRB as a surrogate of SES by zip code results in a useful tool. de Barcelona, and Josep Jimenez, from Departament de Several prior studies have validated this approach of imputing Salut, Generalitat de Catalunya for data management, individual SES in epidemiologic studies reflecting aggregate and Marina Lee Crombie for the English revision. Part characteristics of a population and prevailing habits as well as its of this article appeared on the doctoral thesis of the environmental attributes (such as available health resources) that corresponding author. impact its residents’ health (37, 38). SUPPLEMENTARY MATERIAL CONCLUSION The Supplementary Material for this article can be found Barcelona citizens with lower SES who are admitted with STEMI online at: https://www.frontiersin.org/articles/10.3389/fcvm. show more unfavorable clinical and cardiovascular risk factor 2022.847982/full#supplementary-material Frontiers in Cardiovascular Medicine | www.frontiersin.org 7 April 2022 | Volume 9 | Article 847982 Tizón-Marcos et al. STEMI Network and Socioeconomic Status REFERENCES 17. Biswas S, Andrianopoulos N, Duffy SJ, Lefkovits J, Brennan A, Walton A, et al. Impact of socioeconomic status on clinical outcomes in patients with 1. Roth GA, Johnson C, Abajobir A, Abd-Allah F, Abera SF, Abyu G, et al. Global, st-segment-elevation myocardial infarction. Circ Cardiovasc Qual Outcomes. Regional, and National Burden of Cardiovascular Diseases for 10 Causes, 1990 (2019) 12:e004979. doi: 10.1161/CIRCOUTCOMES.118.004979 to 2015. J Am Coll Cardiol. 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Brugaletta S, Gomez-Lara J, Ortega-Paz L, Jimenez-Diaz V, Jimenez M, Jimenez-Quevedo P, et al. 10-year follow-up of Conflict of Interest: The authors declare that the research was conducted in the patients with everolimus-eluting versus bare-metal stents after ST- absence of any commercial or financial relationships that could be construed as a segment elevation myocardial infarction. J Am Coll Cardiol. (2021) potential conflict of interest. 77:1165–78. doi: 10.1016/j.jacc.2020.12.059 35. Szummer K, Wallentin L, Lindhagen L, Alfredsson J, Erlinge D, Held Publisher’s Note: All claims expressed in this article are solely those of the authors C, et al. Improved outcomes in patients with ST-elevation myocardial and do not necessarily represent those of their affiliated organizations, or those of infarction during the last 20 years are related to implementation of the publisher, the editors and the reviewers. Any product that may be evaluated in evidence-based treatments: experiences from the SWEDEHEART registry this article, or claim that may be made by its manufacturer, is not guaranteed or 1995-2014. Eur Heart J. (2017) 38:3056–65. doi: 10.1093/eurheartj/ endorsed by the publisher. ehx515 36. Hermann M, Witassek F, Erne P, Rickli H, Radovanovic D. Impact of cardiac rehabilitation referral on one-year outcome after discharge of patients with acute myocardial infarction. Copyright © 2022 Tizón-Marcos, Vaquerizo, Ferré, Farré, Lidón, Garcia-Picart, Eur J Prev Cardiol. (2019) 26:138–44. doi: 10.1177/20474873188 Regueiro, Ariza, Carrillo, Duran, Poirier, Cladellas, Camps-Vilaró, Ribas, Cubero- 07766 Gallego and Marrugat. This is an open-access article distributed under the terms 37. Krieger N. Overcoming the absence of socioeconomic data in medical records: of the Creative Commons Attribution License (CC BY). The use, distribution or validation and application of a census-based methodology. Am J Public reproduction in other forums is permitted, provided the original author(s) and the Health. (1992) 82:703–10. doi: 10.2105/AJPH.82.5.703 copyright owner(s) are credited and that the original publication in this journal 38. Smith GD, Hart C, Watt G, Hole D, Hawthorne V. Individual social class, is cited, in accordance with accepted academic practice. No use, distribution or area-based deprivation, cardiovascular disease risk factors, and mortality: the reproduction is permitted which does not comply with these terms. Frontiers in Cardiovascular Medicine | www.frontiersin.org 9 April 2022 | Volume 9 | Article 847982