- Email: [email protected]
Value of CT in Patients Undergoing Self-Expandable TAVR to Assess Outcomes of Concomitant Mitral Regurgitation
JACC: CARDIOVASCULAR IMAGING
VOL. 8, NO. 2, 2015
ª 2015 BY THE AMERICAN COLLEGE OF CARDIOLOGY FOUNDATION
ISSN 1936-878X/$36.00
PUBLISHED BY ELSEVIER INC.
LETTERS TO THE EDITOR
Analysis of MDCT images was carried out by an expert in cardiac imaging (A.R.). Mitral annulus size measured was related to MR improvement with a high echocardiographic/MDCT
Value of CT in Patients Undergoing Self-Expandable TAVR to Assess Outcomes
correlation (0.996; 95% confidence interval [CI]: 0.993
of Concomitant Mitral Regurgitation
to 0.998). The cutoff value that best predicted MR improvement was 35.95 mm. The echocardiographic
Current guidelines on valvular heart disease recommend double valve replacement when significant aortic stenosis and mitral regurgitation (MR) occur simultaneously
(1,2).
Given
the
higher
risk
of
combined mitro-aortic surgery, transcatheter aortic valve replacement (TAVR) has emerged as a good alternative, with a constant improvement (up to 60%) in MR degree after TAVR (3), especially if the MR was of functional etiology. However, the definition of functional MR is challenging in patients with TAVR. The value of multidetector computed tomography (MDCT) in the assessment of mitral valves in this scenario is unknown (4); therefore, our aims were to: 1) confirm the feasibility of mitral valve characterization with MDCT in the context of TAVR; and 2) determine MDCT predictors of MR improvement. One hundred consecutive patients diagnosed with severe aortic stenosis were treated by transfemoral TAVR with the CoreValve system (Medtronic Inc., Minneapolis, Minnesota) in our institution. Six patients with previous mitral mechanical prosthesis were excluded from the analysis. Patients were classified, according to their echocardiographic baseline degree of MR, in “low-degree MR” for grades 0 and 1 (effective regurgitant orifice [ERO] <2 cm2 ; i.e., none or mild) or 2
“high-degree MR” for grades 2, 3, and 4 (ERO $2 cm ; i.e., moderate for 2 and 3 and severe for 4) (1,2). We considered an improvement in MR to be significant when degree of MR changed from high to low. All patients underwent complete serial transthoracic echocardiography. Offline analysis was performed by 3 experienced echocardiographers (A.R., J.R.A., and J.A.S.R.) blinded to further data. Transesophageal echocardiography was only performed when clinically indicated (in 10 patients with ERO $0.3 cm 2 and unclear functional/organic etiology). MDCT examinations were performed with a 64row MDCT scanner (LightSpeed VCR, GE Healthcare, Little Chalfont, United Kingdom) during inspiratory breath-hold using contrast (iohexol 350 mg/ml) in a nongated fashion. MDCT was used to measure mitral annulus diameter. Location and degree of calcification of the mitral annulus and leaflets were semi-quantitatively graded as described in Figure 1.
degree of calcification affecting the mitral valve structures did not show significant differences. In contrast, the presence of any degree of leaflet calcification ($1) by MDCT was an independent predictor of lack of MR improvement (76.5% vs. 23.1%, OR: 6.8 [95% CI: 1.3 to 37.0], p ¼ 0.026), as well as mitral annulus diameter (34.7 3.5 mm vs. 39.7 3.8 mm, OR: 13.5 [95% CI: 2.5 to 76.9], p ¼ 0.003). In addition, the detection of calcium at the mitro-aortic junction by MDCT, related to higher likeliness of left bundle branch block, determined a higher risk of MR persistence. On the contrary, calcification of the mitral annulus was not associated with the evolution of MR. MDCT is particularly useful in patients undergoing TAVR (1,2) to evaluate the aorto-iliac axis and for providing relevant information on mitral valve to predict long-term MR improvement after TAVR. It is not clear why calcification of some of the mitral apparatus elements is associated with MR improvement but not calcification of other parts. We believe that mitral leaflet stiffness provoked by calcium is an important determinant of MR and its remains. These findings will have to be clarified in future prospective research due to the limited number of patients, which restricted multivariate analysis. In conclusion, MDCT analysis of the mitral anatomy in patients undergoing TAVR determined the absence of calcification of mitral leaflets and lower annulus diameter as main predictors of MR improvement. The extended use of MDCT in TAVR candidates and the simplicity of these measurements may be helpful in the decision-making process for patients with mitro-aortic disease given the current controversy about their management. Ignacio J. Amat-Santos, MD* Ana Revilla, MD Javier López, MD, PhD Carlos Cortés, MD Hipólito Gutiérrez, MD Ana Serrador, MD, PhD Federico Gimeno, MD, PhD Ana Puerto, MSc Itziar Gómez, MSc José A. San Román, MD, PhD
JACC: CARDIOVASCULAR IMAGING, VOL. 8, NO. 2, 2015
Letters to the Editor
FEBRUARY 2015:226–31
F I G U R E 1 Different Degrees and Location of Calcification of the Mitral Valve
Mitral valve assessed by multidetector computed tomography (MDCT) (top images of each panel) and echocardiography (bottom images of each panel) in longand short-axis views. (A) Absence of calcification. (B) High degree of annulus calcification (short arrows), without leaflet involvement. (C) High degree of annulus calcification (short arrows) and moderate calcification of the leaflets (long arrows).
*Institute of Heart Sciences Hospital Clínico Universitario de Valladolid C/ Ramón y Cajal 3 47005 Valladolid Spain E-mail: [email protected] http://dx.doi.org/10.1016/j.jcmg.2014.05.019 Please note: Dr. Amat-Santos has received financial support from the Instituto de Salud Carlos III, Madrid, Spain, through a contract “Río Hortega.” All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
2. Vahanian A, Alfieri O, Andreotti F, et al. Guidelines on the management of valvular heart disease (version 2012). Eur J Cardiothorac Surg 2012;42:1–44. 3. Toggweiler S, Boone RH, Rodés-Cabau J, et al. Transcatheter aortic valve replacement: outcomes of patients with moderate or severe mitral regurgitation. J Am Coll Cardiol 2012;59:2068–74. 4. Smith T, Gurudevans S, Cheng V, et al. Assessment of the morphological features of degenerative mitral valve disease using 64-slice multidetector computed tomography. J Cardiovasc Comput Tomogr 2012;6:415–21.
Three-Dimensional Printing of Mitral Valve Using Echocardiographic Data
REFERENCES 1. Bonow RO, Carabello BA, Chatterjee K, et al. 2008 Focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/ American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol 2008;52:e1–142.
Three-dimensional (3D) printing has steadily gained traction as a clinical tool. Current applications include developing patient-specific implants, prostheses, and realistic anatomic models for surgical
227
VOL. 8, NO. 2, 2015
ª 2015 BY THE AMERICAN COLLEGE OF CARDIOLOGY FOUNDATION
ISSN 1936-878X/$36.00
PUBLISHED BY ELSEVIER INC.
LETTERS TO THE EDITOR
Analysis of MDCT images was carried out by an expert in cardiac imaging (A.R.). Mitral annulus size measured was related to MR improvement with a high echocardiographic/MDCT
Value of CT in Patients Undergoing Self-Expandable TAVR to Assess Outcomes
correlation (0.996; 95% confidence interval [CI]: 0.993
of Concomitant Mitral Regurgitation
to 0.998). The cutoff value that best predicted MR improvement was 35.95 mm. The echocardiographic
Current guidelines on valvular heart disease recommend double valve replacement when significant aortic stenosis and mitral regurgitation (MR) occur simultaneously
(1,2).
Given
the
higher
risk
of
combined mitro-aortic surgery, transcatheter aortic valve replacement (TAVR) has emerged as a good alternative, with a constant improvement (up to 60%) in MR degree after TAVR (3), especially if the MR was of functional etiology. However, the definition of functional MR is challenging in patients with TAVR. The value of multidetector computed tomography (MDCT) in the assessment of mitral valves in this scenario is unknown (4); therefore, our aims were to: 1) confirm the feasibility of mitral valve characterization with MDCT in the context of TAVR; and 2) determine MDCT predictors of MR improvement. One hundred consecutive patients diagnosed with severe aortic stenosis were treated by transfemoral TAVR with the CoreValve system (Medtronic Inc., Minneapolis, Minnesota) in our institution. Six patients with previous mitral mechanical prosthesis were excluded from the analysis. Patients were classified, according to their echocardiographic baseline degree of MR, in “low-degree MR” for grades 0 and 1 (effective regurgitant orifice [ERO] <2 cm2 ; i.e., none or mild) or 2
“high-degree MR” for grades 2, 3, and 4 (ERO $2 cm ; i.e., moderate for 2 and 3 and severe for 4) (1,2). We considered an improvement in MR to be significant when degree of MR changed from high to low. All patients underwent complete serial transthoracic echocardiography. Offline analysis was performed by 3 experienced echocardiographers (A.R., J.R.A., and J.A.S.R.) blinded to further data. Transesophageal echocardiography was only performed when clinically indicated (in 10 patients with ERO $0.3 cm 2 and unclear functional/organic etiology). MDCT examinations were performed with a 64row MDCT scanner (LightSpeed VCR, GE Healthcare, Little Chalfont, United Kingdom) during inspiratory breath-hold using contrast (iohexol 350 mg/ml) in a nongated fashion. MDCT was used to measure mitral annulus diameter. Location and degree of calcification of the mitral annulus and leaflets were semi-quantitatively graded as described in Figure 1.
degree of calcification affecting the mitral valve structures did not show significant differences. In contrast, the presence of any degree of leaflet calcification ($1) by MDCT was an independent predictor of lack of MR improvement (76.5% vs. 23.1%, OR: 6.8 [95% CI: 1.3 to 37.0], p ¼ 0.026), as well as mitral annulus diameter (34.7 3.5 mm vs. 39.7 3.8 mm, OR: 13.5 [95% CI: 2.5 to 76.9], p ¼ 0.003). In addition, the detection of calcium at the mitro-aortic junction by MDCT, related to higher likeliness of left bundle branch block, determined a higher risk of MR persistence. On the contrary, calcification of the mitral annulus was not associated with the evolution of MR. MDCT is particularly useful in patients undergoing TAVR (1,2) to evaluate the aorto-iliac axis and for providing relevant information on mitral valve to predict long-term MR improvement after TAVR. It is not clear why calcification of some of the mitral apparatus elements is associated with MR improvement but not calcification of other parts. We believe that mitral leaflet stiffness provoked by calcium is an important determinant of MR and its remains. These findings will have to be clarified in future prospective research due to the limited number of patients, which restricted multivariate analysis. In conclusion, MDCT analysis of the mitral anatomy in patients undergoing TAVR determined the absence of calcification of mitral leaflets and lower annulus diameter as main predictors of MR improvement. The extended use of MDCT in TAVR candidates and the simplicity of these measurements may be helpful in the decision-making process for patients with mitro-aortic disease given the current controversy about their management. Ignacio J. Amat-Santos, MD* Ana Revilla, MD Javier López, MD, PhD Carlos Cortés, MD Hipólito Gutiérrez, MD Ana Serrador, MD, PhD Federico Gimeno, MD, PhD Ana Puerto, MSc Itziar Gómez, MSc José A. San Román, MD, PhD
JACC: CARDIOVASCULAR IMAGING, VOL. 8, NO. 2, 2015
Letters to the Editor
FEBRUARY 2015:226–31
F I G U R E 1 Different Degrees and Location of Calcification of the Mitral Valve
Mitral valve assessed by multidetector computed tomography (MDCT) (top images of each panel) and echocardiography (bottom images of each panel) in longand short-axis views. (A) Absence of calcification. (B) High degree of annulus calcification (short arrows), without leaflet involvement. (C) High degree of annulus calcification (short arrows) and moderate calcification of the leaflets (long arrows).
*Institute of Heart Sciences Hospital Clínico Universitario de Valladolid C/ Ramón y Cajal 3 47005 Valladolid Spain E-mail: [email protected] http://dx.doi.org/10.1016/j.jcmg.2014.05.019 Please note: Dr. Amat-Santos has received financial support from the Instituto de Salud Carlos III, Madrid, Spain, through a contract “Río Hortega.” All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
2. Vahanian A, Alfieri O, Andreotti F, et al. Guidelines on the management of valvular heart disease (version 2012). Eur J Cardiothorac Surg 2012;42:1–44. 3. Toggweiler S, Boone RH, Rodés-Cabau J, et al. Transcatheter aortic valve replacement: outcomes of patients with moderate or severe mitral regurgitation. J Am Coll Cardiol 2012;59:2068–74. 4. Smith T, Gurudevans S, Cheng V, et al. Assessment of the morphological features of degenerative mitral valve disease using 64-slice multidetector computed tomography. J Cardiovasc Comput Tomogr 2012;6:415–21.
Three-Dimensional Printing of Mitral Valve Using Echocardiographic Data
REFERENCES 1. Bonow RO, Carabello BA, Chatterjee K, et al. 2008 Focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/ American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol 2008;52:e1–142.
Three-dimensional (3D) printing has steadily gained traction as a clinical tool. Current applications include developing patient-specific implants, prostheses, and realistic anatomic models for surgical
227