ACCELERATED STREPTOKINASE INFUSION IN THE TREATMENT OF ST ELEVATION MYOCARDIAL INFARCTION

J Gandhara Med Dent Sci. 2023;10


INTRODUCTION
Cardiovascular disease (CVD) is considered one of the important priorities in the health systems of all countries. 1 The burden of these diseases is increasing in low, moderate, and high-income countries. 2 Worldwide, Finland and Japan have the highest and lowest myocardial infarction (MI) incidence rates, respectively. 3,4,5 Since 1987, the adjusted incidence rate of hospitalization for acute myocardial infarction or fatal coronary artery disease in the United States has declined by 4 to 5% per year. 6 Nevertheless, approximately 550,000 rst episodes and 200,000 recurrent episodes of acute myocardial infarction occur Annually. 7 Globally, ischemic heart disease has become the leading contributor to the burden of disease as assessed based on disability-adjusted life years. 8 Ischemic dysfunction of cardiac myocytes during ST elevation myocardial infarction (STEMI) can impair the systolic and diastolic function of the right, left or both ventricles. When the ischemic injury is extensive, the ventricular function can be impaired to such a degree that cardiogenic shock occurs, whereby cardiac output falls and elevated ventricular filling pressures lead to heart failure. 9 The decreased cardiac output then propagates a vicious cycle of progressively worsening coronary perfusion, myocyte dysfunction, and ultimately end organ hypoperfusion. 10 Thrombolytic therapy is easily and quickly administered and is readily available; it requires little skill or equipment, and yields greater benet the sooner it is given after the onset of symptoms. 11 Streptokinase (SK) is a thrombolytic medication and enzyme. As a medication, it is used to break down clots in some cases of myocardial infarction (heart attack), pulmonary embolism, and arterial thromboembolism. The type of heart attack it is used in is an ST Elevation Myocardial Infarction (STEMI). It is used intravenously. Side eects include nausea, bleeding, low blood pressure, and allergic reactions. 12 Streptokinase (SK) is the most widely used fibrinolytic agent especially in economically burdened countries due to the higher cost of the more eective recent generations of brinolytic such as tissue plasminogen activator (t-P A). 13 Most randomized trials used a slow infusion of SK over 60 minutes, this may have been due to concerns regarding ensuing hypotension or hemorrhagic complications of SK with faster regimens. However, some evidence points to the fact that a minimum dose of 500 U/kg/min may be needed for eective tissue level reperfusion, a dose that cannot be obtained with such a relatively slow : : coronary reperfusion was numerically higher in the accelerated SK dose (60.2%) than in the standard dose (57.1%). 15 The other reported ecacy of accelerated SK in patients with STEMI is 62%. 16 The present study is designed to determine the ecacy of accelerated SK in the treatment of newly diagnosed STEMI. Our major concern to conduct this study was that in Peshawar, data regarding the eect of streptokinase in patients with STEMI is lacking especially in the past 5 years. This study will give us fresh local data about the ecacy of accelerated streptokinase SK and will formulate future research strategies to identify the usefulness of accelerated streptokinase (SK) in STEMI patients.

METHODOLOGY
This Descriptive study was done in the Department of Cardiology, Hayatabad Medical Complex over a period of 6 months from august 2020 to February 2021. Age ranged between 35-70 years. Both males and females presenting with acute ST elevation MI, patients within 6 hours of the onset of chest pain were included in the study. Accelerated SK dose regimen defined as 0.75 MU over 10 minutes and followed 50 minutes by the second infusion of 0.75 MU over 10 minutes if there were no ECG signs of coronary reperfusion. The standard dose regimen was dened as 1.5 MU over 60 minutes infused intravenously. Patients with already diagnosed conduction abnormalities, including BBB on medical records, Patients with a history of cardiac interventions, and Patients with a history of renal failure, liver cirrhosis and diabetes (as determined by medical records) were excluded from the study. Statistical analysis was done using SPSS 27.0 for windows. A p-value of ≤ 0.5 was considered signicant.

RESULT
Among 144 patients age distribution was analyzed as 50(35%) patients were in age 35-50 years, and 94(65%) patients were in age 51-70 years. The mean age and standard deviation were 61± 8.19. (Table No  1

DISCUSSION
Cardiovascular disease (CVD) is considered one of the important priorities in the health systems of all countries. 1 The burden of these diseases is increasing in low, moderate, and high-income countries 2 . Worldwide, Finland and Japan have the highest and lowest myocardial infarction (MI) incidence rates, respectively. 3,4,5 Since 1987, the adjusted incidence rate of hospitalization for acute myocardial infarction or fatal coronary artery disease in the United States has declined by 4 to 5% per year. 6 Nevertheless, approximately 550,000 rst episodes and 200,000 recurrent episodes of acute myocardial infarction occur annually. 7 Globally, ischemic heart disease has become the leading contributor to the burden of disease as assessed based on disability-adjusted life years. 8 Ischemic dysfunction of cardiac myocytes during ST elevation myocardial infarction (STEMI) can impair the systolic and diastolic function of the right, left or both ventricles. When the ischemic injury is extensive, the ventricular function can be impaired to such a degree that cardiogenic shock occurs, whereby cardiac output falls and elevated ventricular filling pressures lead to heart failure. 9 The decreased cardiac output then propagates a vicious cycle of progressively worsening coronary perfusion, myocyte dysfunction, and ultimately end-organ hypoperfusion. 10 Our study shows that among 144 patients 50(35%) patients were in age 35-50 years, and 94(65%) patients were in age 51-70 years. The mean age and standard deviation were 61± 8.19. 88(61%) patients were male and 56(39%) patients were female. 69(48%) patients had BMI ≤27 Kg/m2 and 75(52%) patients had BMI >27Kg/m2. 127(88%) patients were hypertensive while 17(12%) patients were non hypertensive. 95(66%) patients were diabetic while 49(34%) patients were non diabetic. Moreover, accelerated streptokinase was eective in 92(64%) patients and was not effective in 52(36%) patients. Similar results were observed in another study conducted by Siriwattana K et al in which There were 423 STEMI patients in the CCU of Nakornping Hospital, 211 patients were treated with SK infusion, but 87 patients from the 211 patients were excluded due to missing data. 15 Therefore, 124 patients were included in the present study. Baseline characteristics were comparable between the two groups. The rate of coronary reperfusion was numerically higher in the accelerated SK dose (60.2%) than in the standard dose (57.1%), but this dierence did not reach statistical significance (p=0.81). No TIMI major bleeding occurred in both group. There was no statistically significant dierence in the hospital mortality rates (accelerated SK dose 3.9% versus standard dose 9.5%, p=0.27). In another study conducted by Bendary A et al concluded similar results in which both groups were statistically matched in all baseline criteria. 16 There was a signicant dierence between both groups regarding each parameter of successful reperfusion in favor of an accelerated regimen. When all these parameters were combined, 31 patients (62%) had successful reperfusion in group I versus 19 patients (38%) in group II (P = 0.016). We did not report any significant dierence between both groups regarding in-hospital mortality, in-hospital heart failure, major bleeding, hypotension or allergic reaction to SK. The mean pre-discharge ejection fraction was higher in group I than in group II (50.9 ± 6.6% versus 47.3 ± 4.6%, P = 0.002). similar ndings were reported by other researchers as well. 17 Research conducted by Ghaari S et al reported that the mean age was 59 ± 12 years (79% male). There were no dierences in baseline data between groups. 18 Clinical, electrocardiographic, and physiologic reperfusion indices revealed signicantly faster and higher reperfusion rates and better preserved LVEF at discharge in group A. Sixty-three per cent of patients in either group underwent invasive coronary angiography at a mean of 5 days with comparable findings. Atrial brillation, malignant ventricular arrhythmias on the second day, and in-hospital and late mortality rates occurred more frequently in group B patients. In multivariate analysis, accelerated SK infusion was the only independent predictor of higher electrocardiographic reperfusion (OR = 3.2, CI: 1.93-5.3, P < 0.001). They concluded that the accelerated SK infusion regimen of 1.5 MU in 20 min is safe and well tolerated with signicantly faster and higher clinical reperfusion rates, more preserved LV systolic function, less atrial and ventricular sustained arrhythmias, and less in-hospital and 1-year mortality rates in acute STEMI.

LIMITATIONS
One of the limitations of our study is the reduced study population carried out in a single tertiary care hospital. Thus to conrm our results, a randomized control trial with a larger sample size should be carried out on patients from dierent hospitals in future.

CONCLUSION
The accelerated SK infusion regimen of 1.5 MU in 20 min is safe and well tolerated with signicantly faster and higher clinical reperfusion rates, more preserved LV systolic function, less atrial and ventricular sustained arrhythmias, and less in-hospital and 1-year mortality rates in acute STEMI.