الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 141 |  |  |
| | | from | 141 | | |
Abstract
The preferred strategy of reperfusion in STEMI patients is primary PCI, which can be defined as coronary angioplasty or stenting without previous administration of fibrinolytic therapy or GPIIb/IIIa antagonists [1]; moreover, these patients are typically treated with aspirin, a loading dose of clopidogrel together with heparin or bivalirudin, prior to the intervention.
However, this procedure has a challenging and serious complication called no reflow phenomenon which is known as insufficient myocardial perfusion even after mechanical reopening of the Infarct-related Artery (IRA) with PCI.
The pathophysiology of no reflow is complicated and not completely understood; it includes much more than just distal embolization of thrombotic debris. Actually, there are many phenomena that contribute to No-Reflow such as: vasoconstriction, leukocytic infiltration, inflammatory pathways activation and cellular oedema.
Predicting patients at risk for no-reflow prior to PCI may be useful from the perspective of prevention but, unfortunately, there is no generally recognized risk stratification approach for predicting this complication. Hence, many studies were done to find a suitable predictive tool for it.
The aim of this work was to evaluate the CHA2DS2-VASc score which is a thromboembolic risk assessment tool recommended in ESC guidelines to be used before starting oral anticoagulant therapy in patients with atrial fibrillation as a simplified applicable tool to predict
Summary
88
the no-reflow phenomenon among patients with STEMI who will undergo primary PCI.
Patients and methods
This prospective study was carried out on patients who were admitted to our PCI capable centre with a diagnosis of acute STEMI who were candidates for primary Percutaneous Coronary Intervention.
Acute STEMI was diagnosed when patients had symptoms of acute myocardial infarction and New ST elevation at the J point in two contiguous leads of ≥0.1 mV in all leads other than leads V2-V3. For leads V2-V3 the following cut points apply: ≥0.2 mV in men ≥40 years, ≥0.25 mV in men.
All the study patients were subjected to full history taking (personal history, history of respiratory and cardiac disorders, and history of any other diseases), thorough Clinical examination (general and local cardiac examinations) and electrocardiogram (rate, rhythm, conduction abnormalities).
All the candidates for primary PCI, received 300 mg of aspirin and 600 mg clopidogrel prior to the procedure. Coronary angiography was performed immediately after STEMI diagnosis using standard technique. Then, 50-70unit/kg of intravenous unfractionated heparin was administered to the patients immediately after the decision of coronary intervention. Thrombus aspiration catheter usage and administration of eptifibatide was chosen according to the decision of the interventional cardiologist.
The TIMI flow grades were evaluated by 2 expert cardiologists who were blinded to each other’s findings and who were blinded to the study design. According to TIMI flow grades after intervention,the
Summary
89
patients were subdivided into two groups,: Normal flow group (60 patients) and no reflow group (21 patients).The normal flow group included patients with TIMI flow rate 3,while the no-reflow group included patients with TIMI flow rate ≤2, despite mechanical reopening of the culprit vessel in patients without coronary dissection.
The mean CHA2DS2-VASc scores of both groups were calculated and studied. It revealed that CHA2DS2-VASc score ≥ 2 may be used as a predictor of the no-reflow phenomenon in patients presented with acute ST segment elevation myocardial infarction with a sensitivity of 97.6% and specificity of 77.5%, area under curve: 0.977 with 95% CI (0.948-1.000).
So, CHA2DS2_VASc score may be used as a simple and applicable tool to predict no-reflow phenomenon before primary PCI in patients diagnosed with acute ST segment elevation myocardial infarction (STEMI).