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Evaluation of prosthetic valve endocarditis by 64-row multidetector computed tomography
International Journal of Cardiology 120 (2007) e27 – e29 www.elsevier.com/locate/ijcard
Letter to the Editor
Evaluation of prosthetic valve endocarditis by 64-row multidetector computed tomography Robert J. Kim a , Jonathan W. Weinsaft a , Tracy Q. Callister b , James K. Min a,⁎ a
Department of Medicine, Division of Cardiology, Weill Medical College of Cornell University, New York Presbyterian Hospital, New York, NY 10021, United States b Tennessee Heart and Vascular Insitute, P.C., Nashville, TN, United States Received 17 January 2007; accepted 4 April 2007 Available online 27 June 2007
Abstract Two patients with prosthetic aortic valves – one bioprosthetic and one mechanical – presented with bacteremia and underwent evaluation for infective prosthetic valve endocarditis. Multidetector computed tomography (MDCT) imaging demonstrated vegetations on both prosthetic valves confirmed by transesophageal echocardiography. Based on the MDCT coronary artery assessment, neither patient underwent pre-operative invasive coronary angiography. Both patients underwent surgical treatment without complication. In conclusion, this report demonstrates that MDCT can, in some cases, accurately image vegetations on prosthetic aortic valves in infective endocarditis. © 2007 Elsevier Ireland Ltd. All rights reserved. Keywords: Multidetector computed tomography; Prosthetic valve; Infective endocarditis
1. Introduction Infective endocarditis affects an estimated 15,000 patients in the United States each year with a mortality rate of approximately 40% [1]. Currently, diagnostic criteria rely upon echocardiography to detect vegetations with high sensitivity due to its superior temporal resolution [2]. Historically, computed tomography has been limited in its ability to detect vegetations due to their rapid, erratic motion and small size. Recent advances in the temporal and spatial resolution of multidetector computed tomography (MDCT), combined with retrospective electrocardiographic gating, now permit cardiac imaging with high accuracy [3]. To date, the ability of MDCT to accurately identify and characterize vegetations remains undefined. We report two cases of prosthetic valve endocarditis – bioprosthetic and mechanical – that were
⁎ Corresponding author. Division of Cardiology, Cornell University Medical Center, 520 E. 70th St., Starr 4, K415, New York, NY 10021, United States. Tel.: +1 212 746 2437; fax: +1 212 746 8561. E-mail address: [email protected] (J.K. Min). 0167-5273/$ - see front matter © 2007 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijcard.2007.04.058
diagnosed by current generation 64-row MDCT and corroborated by traditional imaging. 2. Case descriptions 2.1. Case #1 An 82 year old man with a bioprosthetic aortic valve placed nine years earlier for aortic stenosis and a pacemaker for subsequent third degree AV block presented after several days of fevers and malaise. Multiple blood cultures were positive for Streptococcus mitis. A transesophageal echocardiogram revealed an erratically moving echodensity attached to the ventricular side of the bioprosthetic aortic valve consistent with a vegetation (Fig. 1A and B). A 64-row cardiac MDCT scan performed eight days later demonstrated a similar mass on thin-slice 0.625 mm slices (Fig. 1C, D). Assessment of coronary arteries by MDCT revealed nonobstructive coronary artery disease. The patient underwent successful aortic valve replacement without invasive coronary angiography and pathologic examination confirmed the presence of a vegetation.
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Fig. 1. Bioprosthetic aortic valve vegetation imaged by transesophageal echocardiography and 64-row MDCT. A and B. Short-axis TEE images of the bioprosthetic aortic valve obtained during end-diastole (A) and end-systole (B) demonstrating the presence of a vegetation (white arrow) adherent to the ventricular side of the bioprosthetic valve. C and D. Short-axis MDCT images of the bioprosthetic aortic valve in the identical orientation as the TEE images at the level of the valve leaflets (C) and just inferior (D) demonstrating the same vegetation (black arrow).
2.2. Case #2 A 56 year old man with a mechanical St. Jude's aortic valve placed nine years earlier for aortic stenosis presented for fevers. Multiple blood cultures were positive for Neisseria mucosa. A transthoracic echocardiogram was suggestive of aortic valve endocarditis. 64-row cardiac MDCT performed four days later for assessment of coronary artery disease was negative for obstructive coronary artery disease. The MDCT scan also revealed a mass attached to the sewing ring on the ventricular side of the prosthetic valve, consistent with vegetation (Fig. 2A). A transesophageal echocardiogram performed the next day confirmed the presence of a vegetation (Fig. 2B). He underwent uncomplicated prosthetic aortic valve replacement and was discharged six days later. 3. Comments Infective endocarditis vegetations most often occur on the valve leaflet tips and other sites of turbulent blood flow [1]. Historically, MDCT has been used to evaluate for complications of infective endocarditis including peri-aortic abscesses and septic embolization to the brain, spleen, and pulmonary arteries [4–7]. Advances in the field of MDCT now permit higher spatial and temporal resolution imaging, with current
generation MDCT scanners capable of accurately imaging even the delicate and highly mobile cardiac valves. We report two cases of bacterial endocarditis in which vegetations were clearly apparent on 64-row MDCT images. It is noteworthy to mention that the relatively lower temporal resolution of MDCT as compared to echocardiography makes it unlikely that MDCT will replace echocardiography as the diagnostic imaging modality of choice for the evaluation of infective endocarditis. However, MDCT imaging may assist in diagnosing complications of infective endocarditis (i.e., aneurysms and abscesses). Furthermore, as was illustrated in these two cases, MDCT permits concurrent noninvasive imaging of the coronary arteries, which may be useful for obviating the need for invasive coronary angiography prior to valve replacement surgery [8]. References [1] Bashore TM, Cabell C, Fowler Jr VG. Update on infective endocarditis. Curr Probl Cardiol 2006;31:274–352. [2] Li JS, Sexton DJ, Mick N, et al. Proposed modifications to the Duke criteria for the diagnosis of infective endocarditis. Clin Infect Dis 2000;30:633–8. [3] Hamon M, Biondi-Zoccai GG, Malagutti P, et al. Diagnostic performance of multislice spiral computed tomography of coronary arteries as compared with conventional invasive coronary angiography: a meta-analysis. J Am Coll Cardiol 2006;48:1896–910.
R.J. Kim et al. / International Journal of Cardiology 120 (2007) e27–e29
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[5] Ruttmann E, Willeit J, Ulmer H, et al. Neurological outcome of septic cardioembolic stroke after infective endocarditis. Stroke 2006;37: 2094–9. [6] Ting W, Silverman NA, Arzouman DA, Levitsky S. Splenic septic emboli in endocarditis. Circulation 1990;82(5 Suppl):IV105–9. [7] Ou P, Sidi D, Bonnet D, Brunelle F. Infected pulmonary artery aneurysms: CT imaging findings. Eur J Cardiothorac Surg 2006;29:248. [8] Meijboom WB, Mollet NR, Van Mieghem C, et al. Pre-operative computed tomography coronary angiography to detect significant coronary artery disease in patients referred for cardiac valve surgery. J Am Coll Cardiol 2006;48:1658–65.
Fig. 2. Mechanical aortic valve vegetation imaged by 64-row MDCT and transesophageal echocardiography. A. MDCT image of a vegetation (black arrow) adherent to the ventricular side of the anterior portion of the sewing ring of the mechanical aortic valve prosthesis. B. TEE image of the same vegetation (white arrow) in the identical orientation.
[4] Cowan JC, Patrick D, Reid DS. Aortic root abscess complicating bacterial endocarditis. Demonstration by computed tomography. Br Heart J 1984;52:591–3.
Letter to the Editor
Evaluation of prosthetic valve endocarditis by 64-row multidetector computed tomography Robert J. Kim a , Jonathan W. Weinsaft a , Tracy Q. Callister b , James K. Min a,⁎ a
Department of Medicine, Division of Cardiology, Weill Medical College of Cornell University, New York Presbyterian Hospital, New York, NY 10021, United States b Tennessee Heart and Vascular Insitute, P.C., Nashville, TN, United States Received 17 January 2007; accepted 4 April 2007 Available online 27 June 2007
Abstract Two patients with prosthetic aortic valves – one bioprosthetic and one mechanical – presented with bacteremia and underwent evaluation for infective prosthetic valve endocarditis. Multidetector computed tomography (MDCT) imaging demonstrated vegetations on both prosthetic valves confirmed by transesophageal echocardiography. Based on the MDCT coronary artery assessment, neither patient underwent pre-operative invasive coronary angiography. Both patients underwent surgical treatment without complication. In conclusion, this report demonstrates that MDCT can, in some cases, accurately image vegetations on prosthetic aortic valves in infective endocarditis. © 2007 Elsevier Ireland Ltd. All rights reserved. Keywords: Multidetector computed tomography; Prosthetic valve; Infective endocarditis
1. Introduction Infective endocarditis affects an estimated 15,000 patients in the United States each year with a mortality rate of approximately 40% [1]. Currently, diagnostic criteria rely upon echocardiography to detect vegetations with high sensitivity due to its superior temporal resolution [2]. Historically, computed tomography has been limited in its ability to detect vegetations due to their rapid, erratic motion and small size. Recent advances in the temporal and spatial resolution of multidetector computed tomography (MDCT), combined with retrospective electrocardiographic gating, now permit cardiac imaging with high accuracy [3]. To date, the ability of MDCT to accurately identify and characterize vegetations remains undefined. We report two cases of prosthetic valve endocarditis – bioprosthetic and mechanical – that were
⁎ Corresponding author. Division of Cardiology, Cornell University Medical Center, 520 E. 70th St., Starr 4, K415, New York, NY 10021, United States. Tel.: +1 212 746 2437; fax: +1 212 746 8561. E-mail address: [email protected] (J.K. Min). 0167-5273/$ - see front matter © 2007 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijcard.2007.04.058
diagnosed by current generation 64-row MDCT and corroborated by traditional imaging. 2. Case descriptions 2.1. Case #1 An 82 year old man with a bioprosthetic aortic valve placed nine years earlier for aortic stenosis and a pacemaker for subsequent third degree AV block presented after several days of fevers and malaise. Multiple blood cultures were positive for Streptococcus mitis. A transesophageal echocardiogram revealed an erratically moving echodensity attached to the ventricular side of the bioprosthetic aortic valve consistent with a vegetation (Fig. 1A and B). A 64-row cardiac MDCT scan performed eight days later demonstrated a similar mass on thin-slice 0.625 mm slices (Fig. 1C, D). Assessment of coronary arteries by MDCT revealed nonobstructive coronary artery disease. The patient underwent successful aortic valve replacement without invasive coronary angiography and pathologic examination confirmed the presence of a vegetation.
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R.J. Kim et al. / International Journal of Cardiology 120 (2007) e27–e29
Fig. 1. Bioprosthetic aortic valve vegetation imaged by transesophageal echocardiography and 64-row MDCT. A and B. Short-axis TEE images of the bioprosthetic aortic valve obtained during end-diastole (A) and end-systole (B) demonstrating the presence of a vegetation (white arrow) adherent to the ventricular side of the bioprosthetic valve. C and D. Short-axis MDCT images of the bioprosthetic aortic valve in the identical orientation as the TEE images at the level of the valve leaflets (C) and just inferior (D) demonstrating the same vegetation (black arrow).
2.2. Case #2 A 56 year old man with a mechanical St. Jude's aortic valve placed nine years earlier for aortic stenosis presented for fevers. Multiple blood cultures were positive for Neisseria mucosa. A transthoracic echocardiogram was suggestive of aortic valve endocarditis. 64-row cardiac MDCT performed four days later for assessment of coronary artery disease was negative for obstructive coronary artery disease. The MDCT scan also revealed a mass attached to the sewing ring on the ventricular side of the prosthetic valve, consistent with vegetation (Fig. 2A). A transesophageal echocardiogram performed the next day confirmed the presence of a vegetation (Fig. 2B). He underwent uncomplicated prosthetic aortic valve replacement and was discharged six days later. 3. Comments Infective endocarditis vegetations most often occur on the valve leaflet tips and other sites of turbulent blood flow [1]. Historically, MDCT has been used to evaluate for complications of infective endocarditis including peri-aortic abscesses and septic embolization to the brain, spleen, and pulmonary arteries [4–7]. Advances in the field of MDCT now permit higher spatial and temporal resolution imaging, with current
generation MDCT scanners capable of accurately imaging even the delicate and highly mobile cardiac valves. We report two cases of bacterial endocarditis in which vegetations were clearly apparent on 64-row MDCT images. It is noteworthy to mention that the relatively lower temporal resolution of MDCT as compared to echocardiography makes it unlikely that MDCT will replace echocardiography as the diagnostic imaging modality of choice for the evaluation of infective endocarditis. However, MDCT imaging may assist in diagnosing complications of infective endocarditis (i.e., aneurysms and abscesses). Furthermore, as was illustrated in these two cases, MDCT permits concurrent noninvasive imaging of the coronary arteries, which may be useful for obviating the need for invasive coronary angiography prior to valve replacement surgery [8]. References [1] Bashore TM, Cabell C, Fowler Jr VG. Update on infective endocarditis. Curr Probl Cardiol 2006;31:274–352. [2] Li JS, Sexton DJ, Mick N, et al. Proposed modifications to the Duke criteria for the diagnosis of infective endocarditis. Clin Infect Dis 2000;30:633–8. [3] Hamon M, Biondi-Zoccai GG, Malagutti P, et al. Diagnostic performance of multislice spiral computed tomography of coronary arteries as compared with conventional invasive coronary angiography: a meta-analysis. J Am Coll Cardiol 2006;48:1896–910.
R.J. Kim et al. / International Journal of Cardiology 120 (2007) e27–e29
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[5] Ruttmann E, Willeit J, Ulmer H, et al. Neurological outcome of septic cardioembolic stroke after infective endocarditis. Stroke 2006;37: 2094–9. [6] Ting W, Silverman NA, Arzouman DA, Levitsky S. Splenic septic emboli in endocarditis. Circulation 1990;82(5 Suppl):IV105–9. [7] Ou P, Sidi D, Bonnet D, Brunelle F. Infected pulmonary artery aneurysms: CT imaging findings. Eur J Cardiothorac Surg 2006;29:248. [8] Meijboom WB, Mollet NR, Van Mieghem C, et al. Pre-operative computed tomography coronary angiography to detect significant coronary artery disease in patients referred for cardiac valve surgery. J Am Coll Cardiol 2006;48:1658–65.
Fig. 2. Mechanical aortic valve vegetation imaged by 64-row MDCT and transesophageal echocardiography. A. MDCT image of a vegetation (black arrow) adherent to the ventricular side of the anterior portion of the sewing ring of the mechanical aortic valve prosthesis. B. TEE image of the same vegetation (white arrow) in the identical orientation.
[4] Cowan JC, Patrick D, Reid DS. Aortic root abscess complicating bacterial endocarditis. Demonstration by computed tomography. Br Heart J 1984;52:591–3.