Assessment of stenosis and atherosclerotic plaque volume in coronary arteries in patients with suspected coronary artery disease by angiography using intravascular ultrasound compared to computed tomography scan with 320 layers of detectors

• Grant number: 10/07330-8
• Support Opportunities: Regular Research Grants
• Duration: October 01, 2010 - December 31, 2012
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Noedir Antônio Groppo Stolf
• Grantee: Noedir Antônio Groppo Stolf
• Host Institution: Instituto do Coração Professor Euryclides de Jesus Zerbini (INCOR). Hospital das Clínicas da Faculdade de Medicina da USP (HCFMUSP). Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil
• Associated researchers: Carlos Eduardo Rochitte ; Cristina Akiko Shirahige ; Evelinda Marramon Trindade ; Helena Leiko Ogino ; Luiz Antonio Machado Cesar ; Pedro Alves Lemos Neto

Abstract

In Brazil and worldwide there are concerns about the significant morbidity and mortality burden due to coronary artery disease, CAD. New technologies have emerged showing promising prospects to improve the ability to diagnose this disease. The intravascular ultrasound tomography, IVUS, analyses all arterial layers and dimensions, allowing to discriminate the vessel expansion phenomena attempting to accommodate the atherosclerotic plaque, or positive remodeling, in contrast with the simple angiography, which studies only the arterial lumen. Moreover, rapid advances in computed tomography with multiple layers of detectors, MDCT, have made feasible the non-invasive images of the lumen and wall of the coronary artery. The clinical and costs assessment during the initial period of new technologies incorporation is essential for planning healthcare programs. This study aims to ascertain the sensitivity and specificity of the invasive coronary angiography test under direct visualization with intravascular ultrasound, IVUS, compared to MDCT with 320 layers of detectors, MDCT320, through a systematic literature review and a clinical prospective study of a series of 80 consecutive adult patients with chest pain similar to angina with suspected coronary artery disease and with indeterminate or ambiguous results at the angiography. Moreover, it aims to study the costs, effects, differences in patient management and the economic impact that the adoption of these practices have under the perspective of the Unified Health System in Brazil, the SUS. Specifically, it proposes to evaluate the accuracy of detection of intermediate coronary stenosis, between 70% and e 50%, and the volume of atherosclerotic plaques in coronary arteries. The evaluation of the costs of the diagnostic tests, the healthcare program and its hospital interventions aim: (1) to qualify and quantify the proportion of cases that could have a different clinical and therapeutic management at the empirical reality compared with what is observed in the literature; (2) to evaluate the incremental gains in relation to conventional care with the invasive simple coronary angiography and (3) its potential impact for the SUS upon modeling the projection of analyzed probabilities.The methods include the following parallel dynamics for the systematic review and the InCor-HC/FMUSP clinical study: 1. Systematic and structured critical appraisal of the evidence to list clinical studies including IVUS or CT of the coronary arteries, search in the indexed databases PubMed / NLM-NIH, EMBASE, The Cochrane Library, Center for Reviews and Dissemination (NHS EED, DARE and HTA), EuroScan databases, Ovid / USP and LILACS / BIREME-WHO, analysis of heterogeneity and, if possible, meta-analysis. 2. Prospective clinical study will recruit 80 consecutive patients with chest pain similar to angina with suspected coronary artery disease, who will undergo MDCT320 a priori. All will be evaluated with conventional invasive angiography using IVUS to determine the therapeutic requirements. Patients with coronary stenosis e 50% will be treated according to their treating physician's prescription (in 2008-09, at the InCor-HC/FMUSP, 37% of the patients presented e 50% coronary stenosis requiring angioplasty and 9% required coronary artery bypass grafting). Patients will have follow-up over a period of one year, with review visits scheduled at one, three, six and twelve months, aiming to assess the incidence density of myocardial infarction, stroke, death, MACEs, or other adverse events and to establish their required treatments costs.Scientific knowledge generated, the costs involved in the healthcare program with IVUS and MDCT320, as well as the effects observed, may provide useful parameters for appropriate guidance, program use of resources optimization and planning for the InCor, other institutions and for managers of the SUS. (AU)