IJCS | Volume 31, Nº5, September / October 2018

523 Hoepfner et al. Myocardial infarction in Joinville Int J Cardiovasc Sci. 2018;31(5)520-526 Original Article staff in dealing with ACS patients and symptoms, as well as possibility of transport towell-equipped facilities. 6,7,10,20-23 It is estimated that approximately 20% of patients arrive at the clinics within two hours of pain onset. 2 In fact, public health systems can provide guidance for their users through several actions. 3,10,20 Healthcare providers are expected to be able to identify the disease, especially by recognizing suggestive symptoms and electrocardiographic changes. 1-4,21-23 Electrocardiography (ECG) is an old, cheap test, essential in diagnosing and guiding therapeutic approaches. In 2002, a European task force emphasized the importance for both patients and healthcare providers to identify high-risk chest pain. 24 When symptoms occurred at home, patients wait a mean of 60 minutes before seeking help, and up to 25% of them wait for four hours or more. 7,24 In emergency services, the unawareness of the low sensitivity (approximately 50%) of the ECG test in confirming AMI may affect the diagnosis. The authors reinforced the need for serial ECG at short intervals (minutes) to diagnose the disease, in accordance with Brazilian guidelines recommendations, 1 rather than performing ECG tests every three hours, as usually occurs. Unfortunately, some paramedics do not receive adequate training inECGand rely on cardiac enzyme tests. In STEMI, cardiac enzymes are useful for confirming the event and indicating the prognosis but are not essentially required for the diagnosis. 1-3,21 Delay in the results leads to a delayed and inefficient reperfusion therapy. Boersma et al., 12 in a review of 22 studies published between1983and1993including50,246patientsundergoing coronary thrombolysis showed that the greatest benefit on 30-day mortality is achieved by the therapy performed within the first two hours. In case of STEMI, thrombolytic drugs are recommendedwhenwaiting time to angioplasty is longer than 90 minutes. 7-9,11,13-17 The ACCEPT/SBC (Clinical Outcomes at 30 days in the Brazilian Registry of Acute Coronary Syndromes), 22 a multicenter study of 47 Brazilian hospitals carried out in 2010 and 2011 showed a use of thrombolytic drugs lower than 15%. In addition, reperfusion therapy was not performed in 22.3%of patients with STEMI; mortality in this group was higher than that in the group that received reperfusion therapy (8.1% vs. 2.0%). In the reperfusion group, mean door-to-angiography was 125 (± 90) minutes. The Global Registry of Acute Coronary Events (GRACE), in a six-month follow-up, also showed greater mortality in patients that did not receive reperfusion therapy. 26 In our sample, no patient used thrombolytic drugs (which are not available in the emergency care units but are available in the hospitals). Transluminal angioplasty was performed in 86.1% of patients. Our results indicated that almost all STEMI patients were negatively affected by delayed or absent reperfusion. Approximately 40% of STEMI patients survive the event irrespectively of the medical therapy, and among these patients with less severe infarction, those with late presentation STEMI cause biases in analyzing the benefits of myocardial reperfusion. 10-13 Several reports 3,6,13,15,21-23 have demonstrated that extensive myocardial infarction depends on the best quality medical care to prevent complications and in-hospital and late mortality. Due to incomplete or missing data in the medical records, we could not identify the complications of STEMI. In the study group, two in-hospital deaths were registered, suggesting the presence of less severe conditions in this group. One limitation of the study is the lack of documentation of pain duration before medical assistance in all medical reports. If we assume a 2-hour period for that, 1,4,5,24 fewpatients would have been undergone angioplasty within a four-hour period. Some patients had a very short DAT (10-20 minutes) because the front door, in these cases, was the catheterization laboratory. Only three patients went directly to the referral hospital and hence may have had a pain-door- angiography time shorter than 4 hours. Wang et al., 27 analyzed the data from 101 hospitals in the “Get With the Guidelines” program of the American Heart Association, started in 2000 and reinforced by the D2B Alliance campaign focused on reducing door-to- balloon time. Data of 43,678 AMI patients were compared between 2005 and 2007. After exclusion of patients with non-STEMI, patients transferred in from other hospitals, patients without angioplasty or with late angioplasty, 5,881 patients undergoing primary angioplasty were assessed. Although door-to-balloon time decreased from 101 to 87 minutes, there was no significant reductions (from 5.1% to 4.7%) in in-hospital mortality. Since 2005 data had already revealed satisfactory in-hospital mortality parameters, the authors highlighted the importance of prehospital measures. Between 2002 and 2008 in Denmark, Terkelsen et al., 10 included 13,439 consecutive patients with STEMI referred for reperfusion therapy. The Danish National Health Service provides ambulances equipped with electrocardiographic system and defibrillator. Users