Clinical and Procedural Predictors of Left Ventricular Reverse Remodeling Six Months After First Anterior ST Segment Elevation Myocardial Infarction in Patients Managed By Primary Percutaneous Coronary Intervention

Abstract

SUMMARY A cute myocardial infarction remains a leading cause of morbidity and mortality worldwide. It occurs when irreversible myocardial cell damage or death occur (Bolooki et al., 2010). ST segment elevation myocardial infarction is the most serious presentation of atherosclerotic coronary artery disease carrying the most hazardous consequences (Tosteson et al., 1996). ST segment elevation myocardial infarction is caused by occlusion of a major coronary artery and primary PCI is the preferred reperfusion strategy especially when performed by an experienced team within the shortest possible time from first medical contact (Werf et al., 2008). Left ventricular remodeling is a relatively common and unfavorable event occurring after acute myocardial infarction. The extent of microvascular damage after reperfusion has been identified as one of the main determinant of this process (Galiutol et al., 2008; Carrabba et al., 2012) On the other hand, the opposite phenomenon; left ventricular volume reduction after coronary reperfusion; known as reverse left ventricular remodeling has been poorly investigated; especially after ST elevation myocardial infarction (Carrabba et al., 2012; Bellenger et al., 2005). Reverse remodeling is defined as a reduction more than 10% in left ventricular end systolic volume at 6 months follow up (Kwang et al., 2013; Gray Barn et al., 2008). Few data are available on the extent and prognostic value of reverse left ventricular remodeling after ST elevation myocardial infarction (Carrabba et al., 2012; Kwang et al., 2013) Reverse remodeling describes regression of pathological myocardial hypertrophy, chamber shape distortions, and dysfunction that may occur spontaneously or in response to therapeutic intervention. Favorable reverse remodeling is often associated with improvement in the clinical manifestation of HF (Hellawel et al., 2012). This study was conducted on 95 patients who presented to the cardiology department of Ain Shams university hospital, with first acute anterior STEMI and underwent primary PCI to LAD artery. Patients admitted to the coronary care unit were analyzed thoroughly and data was recorded {Full history taking, clinical examination, 12 lead surface ECG, CK total and CK-MB, coronary angiographic details and transthoracic echocardiography in the first 48 hours}. Medical treatment of STEMI was given to subjects as per hospital protocol. All patients, 6 months after AMI were subjected to echocardiographic evaluation of LV EDV, LV ESV and LVEF. LV reverse remodeling was defined as a decrease in LV ESV ≥ 10 % 6 months after MI. Patients were divided into two groups: Group I: included patients who did not develop LV reverse remodeling and it included 75 patients. Group II: included patients who developed LV reverse remodeling and it included 20 patients. Both groups were studied to determine predictors of LV reverse remodeling after AMI. Both groups were age and sex matched with homogenous risk factors for CAD except for diabetes mellitus and hypertension, in which the reverse remolding cases had lower frequency of DM and higher frequency of HTN compared to non reverse remodeling group with significant difference. At univariate analysis for clinical data, the LV reverse remodeling group showed statistically significantly shorter pain to door time with lower discharge heart rate and lower incidence of pulmonary venous congestion. While for CK total and CK-MB, univariate analysis showed statistically significantly lower CK total and CK-MB in the LV reverse remodeling group and multivariate analysis showed that CK-MB < 300 U/L was an independent predictor of LV reverse remodeling. Meanwhile for coronary angiographic data, univariate analysis showed statistically significantly better TIMI flow before and after reperfusion, better MBG, lower thrombus grade and less use of predilatation in the LV reverse remodeling group but there was no statistically significant difference with respect to site of LAD occlusion, stent length, stent diameter and intracoronary injection of GP IIb/IIIa inhibitors were compared between both groups. However, multivariate analysis showed that TIMI flow after reperfusion 3 and MBG 3 was an independent predictor of LV reverse remodeling.