Utilidade do ultra-som intracoronariano na decisão do tratamento de pacientes com lesões duvidosas no tronco da coronária esquerda

Abstract

Objective: To evaluate the safety and efficacy of surgical treatment approach vs. conservative approach in patients with ambiguous lesions in the left main coronary artery (LMCA), based on intracoronary ultrasound (ICUS) findings. Methods:Sixty-six consecutive patients with angiographically ambiguous lesions were included and submitted to ICUS assessment. They were divided in two groups, according to the ICUS findings. Group I was maintained under clinical treatment [minimal lumen area (MLA) ≥ 6.0 mm 2 and/or minimal lumen diameter (MLD) ≥ 2.5 mm] and Group II was submitted to revascularization (MLA < 6.0 mm 2 and/or MLD < 2.5 mm). The occurrence of major cardiac events (death, acute myocardial infarction and/or revascularization of the target lesion) was assessed during follow-up.Results: Forty-one (62%) patients were allocated in Group I and 25 (38%) in Group II. Mean follow-up was 42.1 months. The coronary angiography did not differentiate the two groups regarding lesion severity (MLD 1.98 mm in Group I vs. 1.72 mm in Group II;p = 0.75) in opposition to ICUS (MLD 3.41 mm in Group I vs. 2.01 mm in Group II;p < 0.001). There was no death or myocardial infarction in Group I. The survival rate free of major cardiac events was 95% in Group I vs. 87.5% in Group II (p=ns). Conclusion:Treatment decision-making of patients with ambiguous lesions in the LMCA guided by ICUS findings showed to be safe and effective. . Referring patients with no significant LMCA lesions for coronary revascularization could lead, however, to the inappropriate use of available grafts, as well as to the premature occlusion of grafts or even of the native arteries. Angiography is considered the standard method of reference and it is most often utilized in the invasive diagnosis of coronary disease. Nevertheless, it can present limitations in some situations, such as when assessing the degree of severity of LMCA lesions. Furthermore, necropsy and intracoronary ultrasound (ICUS) studies have demonstrated several situations in which the LMCA presented significant lesions whereas, frequently, the angiography did not disclose important lesions 5,6 . ICUS is an invasive method that allows the identification of the real dimensions of the vessel and the components of the atherosclerotic plaque and the precise measurement of the arterial lumen, being a more sensitive method than angiography to assess the initial phase of atherosclerosis 7,8 . Several studies have demonstrated the usefulness of ICUS in the identification of LMCA lesions [9][10][11] . The aim of this study is to assess the safety and efficacy of the surgical vs. conservative treatment in patients with ambiguous lesions in the left main coronary artery (LMCA), based on intracoronary ultrasound (ICUS) findings. MethodsPatients -From December 1999 to June 2004, 66 consecutive patients who presented angiographically ambiguous LMCA lesions (moderate lesions, exclusively aortic-ostial lesions, short LMCA lesions, among others) and had been referred for ICUS assessment at the Invasive Cardiolo...