Patterns of coronary artery disease among cardiac patients referred for ct angiography at Muhimbili Hospitals Dar es Salaam, Tanzania Nov 2018 – June 2019

Abstract

Background Coronary artery disease(CAD) is the leading cause of death in many advanced countries with its prevalence increasing among developing countries. In 2001 CAD was responsible for 7.3million deaths and 58million disability-adjusted life years lost worldwide. Invasive coronary angiography (ICA) is widely used as a reliable technique to diagnose CAD. Due to its superior spatial and temporal resolution. However it is invasive and expensive procedure associated with mortality and morbidity(1). In comparison, the application of Coronary Computed TomographyAngiography (CCTA) in the diagnosis of coronary artery disease (CAD), allows for excellent visualization of anatomical details of coronary artery and its branches and is the only imaging modality which has been widely used in the diagnosis of CAD with high diagnostic accuracy.

High quality coronary computed tomography angiography(CCTA) (64slices and above) is not only able to provide reliable information of coronary luminal changes ,but also has the potential to visualize morphological changes of coronary arterial walls, characterize atherosclerotic plaques and identify non stenotic plaques . Despite satisfactory results achieved, CCTA has the disadvantage of high radiation dosing which leads to cancer. Furthermore, Coronary Computed Tomography Angiography (CCTA) plays as a gateway to decide who should go for Invasive Coronary Angiography (ICA) and also performing CCTA is a cost effective strategy in the management of patients. On top of that, in a study of Coronary Computed Tomography Angiography( CCTA),there is a component of Coronary artery calcium score(CACS ) that is performed prior to CCTA and it intends to determine the presence of coronary artery calcifications, although studies have shown that CACS alone cannot be relied upon, in making decision especially to risky and symptomatic patients(2).

Objective: Patterns of coronary artery disease among cardiac patients referred for Computed coronary tomography angiography at Muhimbili Hospitals Dar es Salaam, Tanzania Nov 2018 – June 2019.

Methodology: This wasdescriptivecross-sectional studythat involved220 individuals selected from Patients referred for CCTA at MNH.Dependent variables included (plaque, calcifications, stenosis and occlusion) while Independent variables included (age, gender, hypertension and cigarette smoking), wereanalysed using Chi square or fishers test p value of<0.05, was considered significant. Structured Questionnaires were used to collect data which later were analyzed using SPSS version 23. The images were reported by me and later on were approved by the Senior Radiologist

Results: A total of 220 patients above 50 years were recruited into the study. 49.1% of men were found to have CAD more than female while 57.4% of diabetic patients were found to have CAD than non-diabeticpatients, 78.3% of patients who were smokers had CADand lastly patients above 60 years had CAD more than patients with less or equal to 60 years Furthermore,in a sample size of 220, all patients underwent coronary Computed tomography angiography but 124 patients underwent Coronary calcium protocol and CCTA.Out of 124, 72 patients had no coronary artery calcifications while 52 patients had coronaryartery calcifications. Therefore in a group of 72 patients. Many patients (94.4%) were found to have no coronary calcifications, hence were found to have no CAD on CCTA,however few patients 5.6% without coronary calcifications were found to have soft plaque on CCTA,therefore were confirmed to have CAD.

Among the coronary arteries,the most affected one was LAD whose total plaques were 45.28%, followed by RCA 27.78% and the least one was RI which had 4.7% of plaques.The most affected part of the vessel was the proximal part however middle and distal segments were less affected and also most of the plaques were eccentric in location. Conclusion: Coronary CT Angiography is non invasive and reliable technique to detect and estimate the degree of obstruction,number of affected arteries and pattern of their affection.