Evolutionary and Prognostic Aspects of Thrombolysed Patients for Acute Coronary Syndrome ST+ at CHU Ernesto Guevara De La Serna. Las Tunas (Cuba)

Introduction: Acute myocardial infarction (IDM) occupies the first place in terms of mortality, among ischemic pathologies. Thrombolysis in the case of medical treatment for acute myocardial infarction (AMI) is undoubtedly the most revolutionary performed to date in this context, with a significant reduction in the mortality rate. The aim of our study was to describe the epidemiological aspects, the criteria for myocardial reperfusion post thrombolysis, the complications during thrombolysis and the complications of acute myocardial infarction in the cardiology department of the CHU Ernesto Guevara De La Serna of Las Tunas (Cuba). Methods: A retrospective cross-sectional descriptive study was carried out from June 2009 to December 2011. The patients hospitalized during this period in the USIC (coronary intensive care unit) for SCA ST(+) were included in the study. The variables studied were: Age, sex, myocardial reperfusion criteria, complications during thrombolysis and complications of myocardial infarction. Results: A total of 207 patients were included. The male sex represented 72.5% of the cases, giv-ing a sex ratio of 2.63. The age group > 60 years was predominant with 54.2% of the cases. Thrombolysed patients represented 65.2% of the cases. Myocardial reperfusion criteria were observed in the majority of thrombolysed pa-How tients: relief of precordial pain (77%), regression of the ST segment to 50% of its previous level (81.5% of patients). Bleeding was observed in 1.5% of thrombolysed cases. Complications were encountered in 57% of non thrombolysed patients with a lethality of 5.6%. Conclusion: The male sex was the most affected. Thrombolysis was effective in the majority of patients. The post thrombolysis bleeding rate was low. More than half of the cases of SCA ST(+) not thrombolysed presented complications.


Introduction
One of the leading causes of cardiovascular death and disability is ischemic heart diseases [1] [2] [3]. Among ischemic pathologies, acute myocardial infarction ranks first in terms of mortality. Fibrinolytic therapy for medical treatment of acute myocardial infarction (AMI) is probably the most revolutionary to date in this context [4] [5], with a significant reduction in the mortality rate. According to international reports, this treatment has been used since the 1950s, but with reservations, in 1970 there was an increase in the number of thrombolysed patients. With the belief that the thrombus was a consequence and not the cause of death, thrombolysis was abandoned to be resumed in the years 1982, with the realization of the angiography which demonstrated that the thrombus was the main cause of the infarction acute myocardium in more than 80% of cases, hence thrombolysis has again taken an important place in the treatment of acute myocardial infarction [6]. Large scale multicenter studies have demonstrated: the effectiveness of different fibrinolytic agents in reducing the infarction area, a decrease in mortality, that there were no significant differences between fibrinolytics in terms of efficacy and that intracoronary thrombolysis was not superior to intravenous thrombolysis. Treatment is beneficial only for cases of myocardial infarction with precordialgia [7] [8]. Clarifications were made on the time limit for initiating thrombolysis taking into account the onset of angina pain. A thrombolysis performed in the first 6 hours of the onset of symptoms reduces the infarct area, after 6 hours until 12 hours, we have a reduction in the negative effect of ventricular remodeling, with a significantly lower benefit compared the first 6 hours. The best results are obtained, when thrombolysis is carried out in the first hours of the onset of symptoms [9]. Despite all these clarifications on the benefits of fibrinolytic therapy, we have not achieved a good indicator of the use of this drug in the world. Studies carried out at national level have found a low rate of thrombolysed cases with the main cause of slowness in reaching emergency services [10] [11] [12]. Acute coronary syndrome is the leading cause of death (53.7%) among cardiovascular pathologies according to the annual report of the regional health department of Las Tunas [13] [14]. Previous studies in the region have indicated that the majority of patients with acute coronary syndrome have not had thrombolysis [15]. An increase in the number of thrombolysed patients in our region makes it possible to reduce mortality and improve the prognosis of cases of acute myocardial infarction. Given the importance of fibrinolytic therapy in the management of acute myocardial infarction. We decided to carry out this work with the aim of describing the epidemiological, evolutionary and prognostic aspects of thrombolysed patients hospitalized at CHU Ernesto Guevara De La Serna de Las Tunas.

Materials and Methods
A retrospective and descriptive study was carried out from June 2009 to December 2011 in the cardiology department of the CHU Ernesto Guevara De la Serna of Las Tunas (Cuba). Inclusion criteria: patients hospitalized during this period in the Coronary intensive care unit with the diagnosis of acute coronary syndrome with ST shift (SCA ST+) over clinical and electrocardiographic criteria. The data were collected from medical record. The variables studied were: Socio-demographic characteristics (Age, sex), myocardial reperfusion criteria (clinical and electrocardiographic), complications during thrombolysis, complications of myocardial infarction.
Definition of terms: Thrombolysis: intravenous thrombolysis consists in injecting a substance capable of dissolving the clot that clogs the coronary artery.
The product used was streptokinase, which is a non enzymatic protein produced by the beta hemolytic streptococcus.
Thrombolysis was performed by the nurse assisted by the cardiologist, who was on duty or on call depending on the time of arrival of patients in the cardiology department.
Reperfusion criteria: -Clinic: relief or disappearance of precordial pain after completing thrombolysis. -Electrocardiographic: regression of the ST segment to 50% of the initial elevation level, during the 90 minutes following thrombolysis, appearance of reperfusion arrhythmias. Complications: -Complications of thrombolysis: these are complications that appear during or immediately after completing thrombolysis. Exclusion criteria: patients with infarction without ST segment elevation. Datacollection and processing. The EPI Info V6 program for Windows was used for data collection and analysis. The results presented in the form of tables and graphs.
Ethical Considerations: All patients give their verbal consent, being informed about the procedures in the study, their harmless character and even anonymous treatment of their data.

Results
A total of 207 patients were included. The age group > 60 years was predominant (54.2%), the male sex represented 72.5% of the cases, a sex ratio of 2.63 ( Table 1). The predominance of males in our study could be explained by the fact that women in the fertile stage of their lives are protected by estrogens, which increase high density lipoproteins, which are considered to be anti atherogenic, fulfilling protective functions and thereby decreasing the incidence of heart attacks in women especially those under 50 years. Thrombolysed patients represented 65.2% of the cases ( Table 2). The patients had chest pain before thrombolysis, the majority of patients (77%) had relief of precordial pain after thrombolysis, regression of the ST segment to 50% of its previous level was observed in 81.5% of cases, half of the patients presented with reperfusion arrhythmia (Table 3). Uncomplicated patients during thrombolysis accounted for 82.2% of the cases. Hypotension was the most reported complication 10.4%. Bleeding was observed in 1.5% of patients (Figure 1). Uncomplicated thrombolysed acute myocardial infarction accounted for 95%. The most common complications were respectively: left ventricular dysfunction (2.5%) and ischemic complications (1.5%). In non-thrombolysed patients, complications were observed in 57% of the cases, left ventricular dysfunction (30.6%), followed by ischemic complications (11.1%) were the most represented. Complications were more frequent in cases of non-thrombolysed acute myocardial infarction compared to cases of thrombolysed acute myocardial infarction, hence the importance of thrombolysis in patients with acute myocardial infarction ST+. The thrombolysed patients presented a favorable evolution compared to the non-thrombolysed patients with a lethality of 5.6% (Table 4).

Limits
The main limitation of this study was that streptokinase was the only fibrinolytic product (non selective fibrin) used, because it is the cheapest, while there are other fibrinolytic products (selective fibrin) which have less side effects and complications, but more expensive than streptokinase. Fibrinolytics fibrin selective was not available due to high costs.

Conclusion
The male and elderly were the most affected in our environment, thrombolysis was performed in more than half of the cases in the study. The efficacy criteria for fibrinolysis were observed in the majority of patients. The rate of major complication (bleeding) post thrombolysis was low. More than half of the cases of acute coronary syndrome with over-shift of non thrombolysed ST presented complications. An improvement in the level of education of the population and of health personnel on acute coronary syndrome with ST shift can increase the number of patients to be thrombolysed and consequently a reduction in mortality.