CLINICAL RESEARCH Invasive Cardiology
Prospective Application of Pre-Defined
Intravascular Ultrasound Criteria for Assessment
of Intermediate Left Main Coronary Artery Lesions
Results From the Multicenter LITRO Study
Jose M. de la Torre Hernandez, MD, P
H
D,* Felipe Herna´ndez Hernandez, MD,†
Fernando Alfonso, MD, P
H
D,‡ Jose R. Rumoroso, MD, P
H
D,§ Ramon Lopez-Palop, MD, P
H
D,ʈ
Mario Sadaba, MD,‡ Pilar Carrillo, MD, P
H
D,§ Juan Rondan, MD, P
H
D,¶ Iñigo Lozano, MD, P
H
D,¶
Juan M. Ruiz Nodar, MD, P
H
D,# Jose A. Baz, MD,** Eduard Fernandez Nofrerias, MD,††
Fernando Pajin, MD,‡‡ Tamara Garcia Camarero, MD,* Hipolito Gutierrez, MD,§§
on behalf of the LITRO Study Group (Spanish Working Group on Interventional Cardiology)
Santander, Madrid, Bilbao, Alicante, Oviedo, Vigo, Badalona, Toledo, and Valladolid, Spain
Objectives
This study is a prospective validation of 6 mm
2
as a minimum lumen area (MLA) cutoff value for revasculariza-
tion of left main coronary artery (LMCA) lesions.
Background
Lesions involving the LMCA are prognostically relevant. Angiography has important limitations in the evaluation
of LMCA lesions with intermediate severity. An MLA of 6 mm
2
assessed by intravascular ultrasound has been
proposed as a cutoff value to determine lesion severity, but there are no large studies evaluating the prospective
application and safety of this approach.
Methods
We have designed a multicenter, prospective study. Consecutive patients with intermediate lesions in un-
protected LMCA were evaluated with intravascular ultrasound. An MLA Ͻ6mm
2
was used as criterion for
revascularization.
Results
A total of 354 patients were included in 22 centers. LMCA revascularization was performed in 90.5% (152 of 168) of
patients with an MLA Ͻ6mm
2
and was deferred in 96% (179 of 186) of patients with an MLA of 6 mm
2
or more. A
large scatter was observed between both groups regarding angiographic parameters. In a 2-year follow-up period,
cardiac death-free survival was 97.7% in the deferred group versus 94.5% in the revascularized group (p ϭ 0.5), and
event-free survival was 87.3% versus 80.6%, respectively (p ϭ 0.3). In the 2-year period, only 8 (4.4%) patients in the
deferred group required subsequent LMCA revascularization, none with an infarction.
Conclusions
Angiographic measurements are not reliable in the assessment of intermediate LMCA lesions. An MLA of 6
mm
2
or more is a safe value for deferring revascularization of the LMCA, given the application of the clinical and
angiographic inclusion criteria used in this study. (J Am Coll Cardiol 2011;58:351–8) © 2011 by the American
College of Cardiology Foundation
The limitations of angiographic assessment of left main
coronary artery (LMCA) lesion severity are well established
(1–3). Several studies have been published showing value of
intravascular ultrasound (IVUS) in the assessment of inter-
mediate LMCA lesions (4 –11). A number of publications
have addressed the value of IVUS in deciding whether to treat
an intermediate LMCA lesion (9–11). Some of these studies
were not prospective, the number of patients included was
limited, all were single-center, and different minimum lumen
area (MLA) cutoff values were used (6 to 8 mm
2
).
From the *Hospital Marques de Valdecilla, IFIMAV, Santander, Spain; †Hospital 12
de Octubre, Madrid, Spain; ‡Hospital Clinico San Carlos, Madrid, Spain; §Hospital
de Galdakano, Bilbao, Spain; ʈHospital San Juan, Alicante, Spain; ¶Hospital Central
de Asturias, Oviedo, Spain; #Hospital General, Alicante, Spain; **H. Meixoeiro,
Vigo, Spain; ††H. Germans Trias i Pujol, Badalona, Spain; ‡‡H. Virgen de la Salud,
Toledo, Spain; and the §§H. Clinico de Valladolid, Valladolid, Spain. This work was
supported by Boston Scientific Corporation and GRIFOLS S.A. (distributor for Volcano
Corporation in Spain). The authors have reported that they have no relationships to disclose.
Manuscript received November 3, 2010; revised manuscript received February 3,
2011, accepted February 23, 2011.
Journal of the American College of Cardiology Vol. 58, No. 4, 2011
© 2011 by the American College of Cardiology Foundation ISSN 0735-1097/$36.00
Published by Elsevier Inc. doi:10.1016/j.jacc.2011.02.064