Infective endocarditis at Dr George Mukhari Hospital : correlating echocardiography findings with intraoperative findings

Abstract

Introduction Infective endocarditis is a serious disease that needs rapid diagnosis and accurate risk stratification to offer the best therapeutic strategy. Echocardiography plays a key role in the management of the disease but may be limited in some clinical situations. Moreover, this method is insensitive for very early detection of the infection and assessment of therapeutic response because it does not provide imaging at the molecular and cellular levels. Recently, several novel morphological, molecular and hybrid imaging modalities have been investigated in infective endocarditis and offer new perspectives for better management of the disease. Aims and Objectives of the Study This prospective, quantitative and observational study was investigated at Dr George Mukhari Hospital in Pretoria, South Africa. Infective Endocarditis is a serious disease associated with poor prognosis despite improvements in medical and surgical therapies. Infective Endocarditis results in complex pathogenesis that involves many host-pathogen interactions. Indeed, previous endocardial lesions can lead to the exposure of the underlying extracellular matrix proteins, local inflammation and then thrombus formation, which is termed ‘non-bacterial vegetation’. The project aims to compare the echocardiographic findings (transthoracic echocardiographic-TTE) with intraoperative findings on patients with infective endocarditis. If the correlation existed then the echocardiogram findings were accurate when performed in patients with infective endocarditis. Methodology The research participants consisted of forty (40) patients with infective endocarditis at Dr George Mukhari Hospital in Pretoria, South Africa. A cardiologist examined the patient’s clinically for features of infective endocarditis. Two techniques were used to assess the infective endocarditis. These included echocardiography and Intraoperative findings (visual and histology). Bloods were cultured to demonstrate the presence of micro-organisms. Blood was sent to the laboratory for culture in order to detect the presence of micro-organisms. The researcher performed an Echocardiogram to assess which valve was affected, the left ventricular endiastolic diameter (LVED), the left ventricular ensystolic diameter (LVES), the shortening fraction (SF), the ejection fraction (EF) and the size of the vegetation/mass or abscess. For patients requiring a heart surgery, the cardiac surgeon performed the valve replacement, and the intra-operative findings was assessed visually to confirm the presence of vegetation or abscess and leaflets destruction. During the operation, which was performed by the same cardiac surgeon, a biopsy sample was taken for histological examination to confirm the presence of vegetation or abscess. Thereafter, the cardiac surgeon performed the valve repair/ replacement/ bioprosthesis. The researcher was blinded to the findings in the theatre as the researcher was not present in the theatre. The results from the laboratory was sent to the researcher. The researcher was then able to confirm the presence of vegetation or mass/ abscess and leaf destruction. Results The histology confirmed what was seen on echocardiographical findings and intraoperative findings (visual). The intraoperative and echocardiography findings showed thirty two of 40 (80%) vegetation, two of 40 (5%) perforation, four of 40 (10%) pseudoaneursym and two of 40 (5%) abscesses. The prognosis of patients with poor ejection fraction (40-50% EF) was poorer than those with good ejection fraction (60-75%). The clinical findings of all patients confirmed infective endocarditis and thirty two of 40 (80%) blood cultures were positive and eight of 40 (20%) were negative. There were seven of 40 (17,5%) patients who showed poor correlation 40- 50% between echocardiographical findings and post-operative findings. The results of thirty three of 40 (82%) patients showed moderate correlation 69% between the echocardiographical findings and post-operative findings. Conclusion My findings of the study was that eight of 40 (20%) had stenosis and thirty two of 40 (80%) had regurgitation in patients who had infective endocarditis. There was an overall moderate association (r=0.68) between echocardiography and the intraoperative findings in all patients for LVES.