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A rare case of spontaneously dissolved calcification of the mitral annulus: Caseous calcification of the mitral annulus
G Model
JCCASE-914; No. of Pages 4 Journal of Cardiology Cases xxx (2017) xxx–xxx
Contents lists available at ScienceDirect
Journal of Cardiology Cases journal homepage: www.elsevier.com/locate/jccase
Case Report
A rare case of spontaneously dissolved calcification of the mitral annulus: Caseous calcification of the mitral annulus Yasuyo Takeuchi (MD)a,b,*, Makoto Motooka (MD, PhD)b, Hiroki Sakamoto (MD)b, Genichi Sakaguchi (MD, PhD)c, Hiroyuki Watanabe (MD, PhD, FJCC)d, Toshio Shimada (MD, PhD, FJCC)e a
Department of Clinical Laboratory Medicine, Shizuoka General Hospital, Shizuoka, Japan Department of Cardiology, Shizuoka General Hospital, Shizuoka, Japan c Department of Cardiovascular Surgery, Shizuoka General Hospital, Shizuoka, Japan d Department of Cardiology, Heart Center, Tokyo Bay Urayasu Ichikawa Medical Center, Chiba, Japan e Clinical Research Center, Shizuoka General Hospital, Shizuoka, Japan b
A R T I C L E I N F O
A B S T R A C T
Article history: Received 14 April 2017 Received in revised form 1 November 2017 Accepted 10 November 2017
Caseous calcification of the mitral annulus is a rare variant of mitral annular calcification (MAC). MAC is detected using conventional echocardiography and is prevalent in the elderly. However, limited information is currently available on the transformation of MAC. We herein report a case of a sudden liquified change in MAC, which was diagnosed using echocardiography and computed tomography. © 2017 Published by Elsevier Ltd on behalf of Japanese College of Cardiology.
Keywords: Mitral annular calcification Echocardiography Caseous calcification of the mitral annulus
Introduction Mitral annular calcification (MAC) was first described in 1908 by Bönninger et al. and was reported to be associated with conduction disturbances [1]. It is a degenerative process involving the fibrous annulus of the mitral valve and is more common in the elderly, particularly in osteoporotic women [2]. The occurrence of MAC is rather associated with atherosclerosis than degenerative changes in the mitral valve [3]. Caseous calcification of the mitral annulus (CCMA) is a rare variant of MAC. The incidence of CCMA diagnosed by echocardiography was previously reported to be 0.068% in all the patients undergoing echocardiography and 0.64% in MAC cases [4]. CCMA resembles a large mass, similar to a tumor or abscess [5]. It has the appearance of a soft and echo-dense mass that is composed of a liquefaction lesion with calcium, fatty acid, and cholesterol admixture at the periannular area of the mitral valve [5].
* Corresponding author at: Department of Cardiology, Shizuoka General Hospital, 4-27-1 Kita-ando, Aoi-Ku, Shizuoka, Japan. E-mail address: [email protected] (Y. Takeuchi).
The mechanisms by which CCMA is organized and formed currently remain unclear. One previous study on CCMA proposed a dynamic process based on the transformation of MAC, with CCMA reverting to MAC in some patients [4]. We herein report a case of a 75-year-old woman who presented with a marked transition to CCMA from MAC, as observed using echocardiography and computed tomography.
Case report A 75-year-old woman visited the attending hospital with hypertension, dyslipidemia, and implantation of a DDD pacemaker due to complete atrioventricular block. During her visit to London between December 30th, 2014 and January 2nd, 2015, she was hospitalized due to transient cerebral ischemic attack (TIA). After she had returned to Japan, she visited our hospital on January 5th. At the time of her visit to our hospital, her blood pressure was 140/70 mmHg, and her heart rate was 64 beats per minute (bpm). Consciousness was clear, and there were no other remarkable neurological findings. Chest X-ray revealed no pulmonary congestion and no other significant findings. An electrocardiogram showed a heart rate of 65 bpm
https://doi.org/10.1016/j.jccase.2017.11.001 1878-5409/© 2017 Published by Elsevier Ltd on behalf of Japanese College of Cardiology.
Please cite this article in press as: Takeuchi Y, et al. A rare case of spontaneously dissolved calcification of the mitral annulus: Caseous calcification of the mitral annulus. J Cardiol Cases (2017), https://doi.org/10.1016/j.jccase.2017.11.001
G Model
JCCASE-914; No. of Pages 4 Y. Takeuchi et al. / Journal of Cardiology Cases xxx (2017) xxx–xxx
2
Fig. 1.
Transthoracic echocardiography showing a long-axis view (A) and short-axis view (B) at the level of the mitral ring of the echolucent area with encircling calcification. Transesophageal echocardiograph of the mid-esophageal level (C) and a real-time three-dimensional transesophageal echocardiographic image from the left atrium (D). The mass was visualized as a central low echoic area surrounded by calcification at the peri-annular site. The supramitral valve of the left atrium surface was smooth and protruded beyond the mitral annulus level.
and a normal sinus rhythm. Laboratory results were within normal ranges for creatinine, transaminase, and total bilirubin levels as well as blood counts. Her pacemaker log showed the trace of paroxysmal atrial fibrillation. After returning to Japan, head computed tomography was performed and revealed old cerebellar infarction. Accordingly, she was treated with apixaban (a factor Xa inhibitor). Echocardiography showed a large mass in the posterior mitral annulus. The mass was soft and moved with the surrounding tissue. Its appearance was echo-lucent in the central area, and a calcified ring encircled the mass (Fig. 1). This echocardiographic finding was different from that of five years previously (Fig. 2). Moreover, computed tomograms revealed a similar change (Fig. 3). The echocardiograms and computed tomograms, which were taken five years before pacemaker implantation, showed markedly
Fig. 2.
different appearance. For these five years, calcification progressed abruptly from MAC to CCMA. We considered the extirpation of CCMA as a therapeutic strategy. However, CCMA was already widespread around the mitral annulus. If CCMA was removed, reconstructive surgery might have been difficult. After much deliberation, the oral administration of anticoagulants was initiated, and as a result, the cerebrovascular disease never recurred. Careful observation and medication have been continued until now. Discussion MAC is characterized by the calcification with chronic fibrosis and degeneration of the ring-like tissue supporting the mitral valve. The prevalence of MAC is 9% and is strongly associated with
Transthoracic echocardiography 5 years previously showing a long-axis view (A) and short-axis view (B) at the level of the mitral ring of a bulky calcified homogeneous area with an acoustic shadow under the mass.
Please cite this article in press as: Takeuchi Y, et al. A rare case of spontaneously dissolved calcification of the mitral annulus: Caseous calcification of the mitral annulus. J Cardiol Cases (2017), https://doi.org/10.1016/j.jccase.2017.11.001
G Model
JCCASE-914; No. of Pages 4 Y. Takeuchi et al. / Journal of Cardiology Cases xxx (2017) xxx–xxx
Fig. 3.
3
Computed tomography showing sagittal plane (A) and coronal plane (B) images. A low area attenuated by a calcified layer was observed inside the mass. Computed tomography five years previously showing an axial plane image (C) and vertical plane image with contrast (D). A hyperdense and calcified homogeneous mass was observed below the mitral annulus.
older age, female gender, diabetes mellitus, and increased body mass index [2]. Moreover, MAC has been implicated in the incidence of stroke [6] and cardiovascular diseases as well as the mortality of cardiovascular diseases [1]. The occurrence of conduction defects was previously reported significantly to increase in MAC patients [1]. Thus, in this case, pacemaker implantation was necessary because of the previously developed complete atrioventricular block. The mechanisms of MAC formation remain controversial from the viewpoint of pathophysiology. Carpentier et al. [7] indicated that repeating excessive tension and stress resulting from redundant tissue, according to Laplace’s law, leads to MAC formation. In addition to mechanical factors, biochemical factors may play a role. A vicious cycle is initiated by the degenerative valvular process with collagen denaturation, attributed to increased tension and fragility of tissue and leaflets. The vicious cycle ultimately results in annulus dehiscence and ischemia with the deposition of lipid, protein, blood cell, and calcium phosphate [7]. MAC has frequently been observed in patients with chronic kidney disease [8], and more frequently observed in patients with end-stage renal disease. It has been associated with elevated levels of calcium-phosphorus products, vascular calcification, hypercalcemia, and hyperphosphatemia in hemodialysis patients. Varma et al. also reported the prevalence of valve calcification in hemodialysis patients [9]. All-cause mortality was 56% in patients with MAC and 38% in patients without MAC (p = 0.044) and was 59% in patients with aortic valve calcium and 29% in patients without valve calcium (p = 0.0005) [9]. CCMA is a rare variant of MAC. Consequently, the mechanisms leading to liquefaction necrosis associated with CCMA have not
been understood yet. In one study, a microscopic examination of CCMA revealed amorphous eosinophilic acellular material surrounded by macrophages and lymphocytes; other areas had multiple calcifications and zones of necrosis [10]. Thus, the central liquefaction area appears to be echo-lucent and less reflective. This case may have provided rare and highly suggestive information that may enable us to prevent MAC from progressing to a more serious pathophysiological condition such as CCMA or severe complications. Once a stroke occurs, quality of life may deteriorate. Therefore, MAC may not be necessarily benign in clinical practice. If MAC is detected, comprehensive management, including the prevention of stroke, may be needed for patients with multiple risk factors for atherosclerosis. MAC is a common echocardiographic finding in a super-aging society. In this case, TIA has not recurred after starting anticoagulant oral administration. It is highly likely that TIA occurred due to cardiogenic embolism caused by paroxysmal atrial fibrillation. However, the possibility that CCMA is the cause of TIA could not be excluded at all; careful and repetitive observations might have been helpful for the detection of possible transitions. On the other hand, CCMA or MAC is highly likely to be associated with any inflammation and may have contributed directly or indirectly to an increased incidence rate of atrial fibrillation. Therefore, cerebrovascular adverse events may be predicted, based on reliable information obtained from echocardiography and CT imaging. In conclusion, this case report revealed the transition from MAC to CCMA, indicating the marked transformation with calcification, which leads to spontaneous liquefaction.
Please cite this article in press as: Takeuchi Y, et al. A rare case of spontaneously dissolved calcification of the mitral annulus: Caseous calcification of the mitral annulus. J Cardiol Cases (2017), https://doi.org/10.1016/j.jccase.2017.11.001
G Model
JCCASE-914; No. of Pages 4 Y. Takeuchi et al. / Journal of Cardiology Cases xxx (2017) xxx–xxx
4
Funding No funding was required to support this publication. Conflicts of interest The authors declare that there is no conflict of interest. References [1] Fox CS, Vasan RS, Parise H, Levy D, O’Donnell CJ, D’Agostino RB, et al. Mitral annular calcification predicts cardiovascular morbidity and mortality: The Framingham Heart Study. Circulation 2003;107:1492–6. [2] Somsupha K, Khurram N, Ronit K, Juan J. Relationship of mitral annular calcification to cardiovascular risk factors: the multi-ethnic study of atherosclerosis (MESA). Atherosclerosis 2010;213:558–62. [3] Hamirani YS, Nasir K, Blumenthal RS, Takasu J, Shavelle D, Kronmal R, et al. Relation of mitral annular calcium and coronary calcium (from the MultiEthnic Study of Atherosclerosis [MESA]). Am J Cardiol 2011;107:1291–4.
[4] Deluca G, Correale M, Ieva R, Del Salvatore B, Gramenzi S, Di Biase M. The incidence and clinical course of caseous calcification of the mitral annulus: a prospective echocardiographic study. J Am Soc Echocardiogr 2008;21:828. [5] Alkadhi H, Leschka S, Preˆtre R, Perren A, Marincek B, Wildermuth S. Caseous calcification of the mitral annulus. J Thorac Cardiovasc Surg 2005;129:1438– 40. [6] Benjamin EJ, Plehn JF, D’Agostino RB, Belanger AJ, Comai K, Fuller DL, et al. Mitral annular calcification and the risk of stroke in elderly cohort. N Engl J Med 1992;327:374–9. [7] Carpentier AF, Pellerin M, Fuzellier JF, Relland JY. Extensive calcification of the mitral valve annulus: pathophysiology and surgical management. J Thorac Cardiovasc Surg 1996;111:718–30. [8] Asselbergs FW, Mozaffarian D, Katz R, Kestenbaum B, Fried LF, Gottdiener JS, et al. Association of renal function with cardiac calcifications in older adults: the cardiovascular health study. Nephrol Dial Transplant 2009;24:834–40. [9] Varma R, Aronow WS, McClung JA, Garrick R, Vistainer PF, Weiss MB, et al. Prevalence of valve calcium and association of valve calcium with coronary artery disease, atherosclerotic vascular disease, and all-cause mortality in 137 patients undergoing hemodialysis for chronic renal failure. Am J Cardiol 2005;95:742–3. [10] Harpaz D, Auerbach I, Vered Z, Motro M, Tobar A, Rosenblatt S. Caseous calcification of the mitral annulus: a neglected, unrecognized diagnosis. J Am Soc Echocardiogr 2001;14:825–31.
Please cite this article in press as: Takeuchi Y, et al. A rare case of spontaneously dissolved calcification of the mitral annulus: Caseous calcification of the mitral annulus. J Cardiol Cases (2017), https://doi.org/10.1016/j.jccase.2017.11.001
JCCASE-914; No. of Pages 4 Journal of Cardiology Cases xxx (2017) xxx–xxx
Contents lists available at ScienceDirect
Journal of Cardiology Cases journal homepage: www.elsevier.com/locate/jccase
Case Report
A rare case of spontaneously dissolved calcification of the mitral annulus: Caseous calcification of the mitral annulus Yasuyo Takeuchi (MD)a,b,*, Makoto Motooka (MD, PhD)b, Hiroki Sakamoto (MD)b, Genichi Sakaguchi (MD, PhD)c, Hiroyuki Watanabe (MD, PhD, FJCC)d, Toshio Shimada (MD, PhD, FJCC)e a
Department of Clinical Laboratory Medicine, Shizuoka General Hospital, Shizuoka, Japan Department of Cardiology, Shizuoka General Hospital, Shizuoka, Japan c Department of Cardiovascular Surgery, Shizuoka General Hospital, Shizuoka, Japan d Department of Cardiology, Heart Center, Tokyo Bay Urayasu Ichikawa Medical Center, Chiba, Japan e Clinical Research Center, Shizuoka General Hospital, Shizuoka, Japan b
A R T I C L E I N F O
A B S T R A C T
Article history: Received 14 April 2017 Received in revised form 1 November 2017 Accepted 10 November 2017
Caseous calcification of the mitral annulus is a rare variant of mitral annular calcification (MAC). MAC is detected using conventional echocardiography and is prevalent in the elderly. However, limited information is currently available on the transformation of MAC. We herein report a case of a sudden liquified change in MAC, which was diagnosed using echocardiography and computed tomography.
Keywords: Mitral annular calcification Echocardiography Caseous calcification of the mitral annulus
Introduction Mitral annular calcification (MAC) was first described in 1908 by Bönninger et al. and was reported to be associated with conduction disturbances [1]. It is a degenerative process involving the fibrous annulus of the mitral valve and is more common in the elderly, particularly in osteoporotic women [2]. The occurrence of MAC is rather associated with atherosclerosis than degenerative changes in the mitral valve [3]. Caseous calcification of the mitral annulus (CCMA) is a rare variant of MAC. The incidence of CCMA diagnosed by echocardiography was previously reported to be 0.068% in all the patients undergoing echocardiography and 0.64% in MAC cases [4]. CCMA resembles a large mass, similar to a tumor or abscess [5]. It has the appearance of a soft and echo-dense mass that is composed of a liquefaction lesion with calcium, fatty acid, and cholesterol admixture at the periannular area of the mitral valve [5].
* Corresponding author at: Department of Cardiology, Shizuoka General Hospital, 4-27-1 Kita-ando, Aoi-Ku, Shizuoka, Japan. E-mail address: [email protected] (Y. Takeuchi).
The mechanisms by which CCMA is organized and formed currently remain unclear. One previous study on CCMA proposed a dynamic process based on the transformation of MAC, with CCMA reverting to MAC in some patients [4]. We herein report a case of a 75-year-old woman who presented with a marked transition to CCMA from MAC, as observed using echocardiography and computed tomography.
Case report A 75-year-old woman visited the attending hospital with hypertension, dyslipidemia, and implantation of a DDD pacemaker due to complete atrioventricular block. During her visit to London between December 30th, 2014 and January 2nd, 2015, she was hospitalized due to transient cerebral ischemic attack (TIA). After she had returned to Japan, she visited our hospital on January 5th. At the time of her visit to our hospital, her blood pressure was 140/70 mmHg, and her heart rate was 64 beats per minute (bpm). Consciousness was clear, and there were no other remarkable neurological findings. Chest X-ray revealed no pulmonary congestion and no other significant findings. An electrocardiogram showed a heart rate of 65 bpm
https://doi.org/10.1016/j.jccase.2017.11.001 1878-5409/© 2017 Published by Elsevier Ltd on behalf of Japanese College of Cardiology.
Please cite this article in press as: Takeuchi Y, et al. A rare case of spontaneously dissolved calcification of the mitral annulus: Caseous calcification of the mitral annulus. J Cardiol Cases (2017), https://doi.org/10.1016/j.jccase.2017.11.001
G Model
JCCASE-914; No. of Pages 4 Y. Takeuchi et al. / Journal of Cardiology Cases xxx (2017) xxx–xxx
2
Fig. 1.
Transthoracic echocardiography showing a long-axis view (A) and short-axis view (B) at the level of the mitral ring of the echolucent area with encircling calcification. Transesophageal echocardiograph of the mid-esophageal level (C) and a real-time three-dimensional transesophageal echocardiographic image from the left atrium (D). The mass was visualized as a central low echoic area surrounded by calcification at the peri-annular site. The supramitral valve of the left atrium surface was smooth and protruded beyond the mitral annulus level.
and a normal sinus rhythm. Laboratory results were within normal ranges for creatinine, transaminase, and total bilirubin levels as well as blood counts. Her pacemaker log showed the trace of paroxysmal atrial fibrillation. After returning to Japan, head computed tomography was performed and revealed old cerebellar infarction. Accordingly, she was treated with apixaban (a factor Xa inhibitor). Echocardiography showed a large mass in the posterior mitral annulus. The mass was soft and moved with the surrounding tissue. Its appearance was echo-lucent in the central area, and a calcified ring encircled the mass (Fig. 1). This echocardiographic finding was different from that of five years previously (Fig. 2). Moreover, computed tomograms revealed a similar change (Fig. 3). The echocardiograms and computed tomograms, which were taken five years before pacemaker implantation, showed markedly
Fig. 2.
different appearance. For these five years, calcification progressed abruptly from MAC to CCMA. We considered the extirpation of CCMA as a therapeutic strategy. However, CCMA was already widespread around the mitral annulus. If CCMA was removed, reconstructive surgery might have been difficult. After much deliberation, the oral administration of anticoagulants was initiated, and as a result, the cerebrovascular disease never recurred. Careful observation and medication have been continued until now. Discussion MAC is characterized by the calcification with chronic fibrosis and degeneration of the ring-like tissue supporting the mitral valve. The prevalence of MAC is 9% and is strongly associated with
Transthoracic echocardiography 5 years previously showing a long-axis view (A) and short-axis view (B) at the level of the mitral ring of a bulky calcified homogeneous area with an acoustic shadow under the mass.
Please cite this article in press as: Takeuchi Y, et al. A rare case of spontaneously dissolved calcification of the mitral annulus: Caseous calcification of the mitral annulus. J Cardiol Cases (2017), https://doi.org/10.1016/j.jccase.2017.11.001
G Model
JCCASE-914; No. of Pages 4 Y. Takeuchi et al. / Journal of Cardiology Cases xxx (2017) xxx–xxx
Fig. 3.
3
Computed tomography showing sagittal plane (A) and coronal plane (B) images. A low area attenuated by a calcified layer was observed inside the mass. Computed tomography five years previously showing an axial plane image (C) and vertical plane image with contrast (D). A hyperdense and calcified homogeneous mass was observed below the mitral annulus.
older age, female gender, diabetes mellitus, and increased body mass index [2]. Moreover, MAC has been implicated in the incidence of stroke [6] and cardiovascular diseases as well as the mortality of cardiovascular diseases [1]. The occurrence of conduction defects was previously reported significantly to increase in MAC patients [1]. Thus, in this case, pacemaker implantation was necessary because of the previously developed complete atrioventricular block. The mechanisms of MAC formation remain controversial from the viewpoint of pathophysiology. Carpentier et al. [7] indicated that repeating excessive tension and stress resulting from redundant tissue, according to Laplace’s law, leads to MAC formation. In addition to mechanical factors, biochemical factors may play a role. A vicious cycle is initiated by the degenerative valvular process with collagen denaturation, attributed to increased tension and fragility of tissue and leaflets. The vicious cycle ultimately results in annulus dehiscence and ischemia with the deposition of lipid, protein, blood cell, and calcium phosphate [7]. MAC has frequently been observed in patients with chronic kidney disease [8], and more frequently observed in patients with end-stage renal disease. It has been associated with elevated levels of calcium-phosphorus products, vascular calcification, hypercalcemia, and hyperphosphatemia in hemodialysis patients. Varma et al. also reported the prevalence of valve calcification in hemodialysis patients [9]. All-cause mortality was 56% in patients with MAC and 38% in patients without MAC (p = 0.044) and was 59% in patients with aortic valve calcium and 29% in patients without valve calcium (p = 0.0005) [9]. CCMA is a rare variant of MAC. Consequently, the mechanisms leading to liquefaction necrosis associated with CCMA have not
been understood yet. In one study, a microscopic examination of CCMA revealed amorphous eosinophilic acellular material surrounded by macrophages and lymphocytes; other areas had multiple calcifications and zones of necrosis [10]. Thus, the central liquefaction area appears to be echo-lucent and less reflective. This case may have provided rare and highly suggestive information that may enable us to prevent MAC from progressing to a more serious pathophysiological condition such as CCMA or severe complications. Once a stroke occurs, quality of life may deteriorate. Therefore, MAC may not be necessarily benign in clinical practice. If MAC is detected, comprehensive management, including the prevention of stroke, may be needed for patients with multiple risk factors for atherosclerosis. MAC is a common echocardiographic finding in a super-aging society. In this case, TIA has not recurred after starting anticoagulant oral administration. It is highly likely that TIA occurred due to cardiogenic embolism caused by paroxysmal atrial fibrillation. However, the possibility that CCMA is the cause of TIA could not be excluded at all; careful and repetitive observations might have been helpful for the detection of possible transitions. On the other hand, CCMA or MAC is highly likely to be associated with any inflammation and may have contributed directly or indirectly to an increased incidence rate of atrial fibrillation. Therefore, cerebrovascular adverse events may be predicted, based on reliable information obtained from echocardiography and CT imaging. In conclusion, this case report revealed the transition from MAC to CCMA, indicating the marked transformation with calcification, which leads to spontaneous liquefaction.
Please cite this article in press as: Takeuchi Y, et al. A rare case of spontaneously dissolved calcification of the mitral annulus: Caseous calcification of the mitral annulus. J Cardiol Cases (2017), https://doi.org/10.1016/j.jccase.2017.11.001
G Model
JCCASE-914; No. of Pages 4 Y. Takeuchi et al. / Journal of Cardiology Cases xxx (2017) xxx–xxx
4
Funding No funding was required to support this publication. Conflicts of interest The authors declare that there is no conflict of interest. References [1] Fox CS, Vasan RS, Parise H, Levy D, O’Donnell CJ, D’Agostino RB, et al. Mitral annular calcification predicts cardiovascular morbidity and mortality: The Framingham Heart Study. Circulation 2003;107:1492–6. [2] Somsupha K, Khurram N, Ronit K, Juan J. Relationship of mitral annular calcification to cardiovascular risk factors: the multi-ethnic study of atherosclerosis (MESA). Atherosclerosis 2010;213:558–62. [3] Hamirani YS, Nasir K, Blumenthal RS, Takasu J, Shavelle D, Kronmal R, et al. Relation of mitral annular calcium and coronary calcium (from the MultiEthnic Study of Atherosclerosis [MESA]). Am J Cardiol 2011;107:1291–4.
[4] Deluca G, Correale M, Ieva R, Del Salvatore B, Gramenzi S, Di Biase M. The incidence and clinical course of caseous calcification of the mitral annulus: a prospective echocardiographic study. J Am Soc Echocardiogr 2008;21:828. [5] Alkadhi H, Leschka S, Preˆtre R, Perren A, Marincek B, Wildermuth S. Caseous calcification of the mitral annulus. J Thorac Cardiovasc Surg 2005;129:1438– 40. [6] Benjamin EJ, Plehn JF, D’Agostino RB, Belanger AJ, Comai K, Fuller DL, et al. Mitral annular calcification and the risk of stroke in elderly cohort. N Engl J Med 1992;327:374–9. [7] Carpentier AF, Pellerin M, Fuzellier JF, Relland JY. Extensive calcification of the mitral valve annulus: pathophysiology and surgical management. J Thorac Cardiovasc Surg 1996;111:718–30. [8] Asselbergs FW, Mozaffarian D, Katz R, Kestenbaum B, Fried LF, Gottdiener JS, et al. Association of renal function with cardiac calcifications in older adults: the cardiovascular health study. Nephrol Dial Transplant 2009;24:834–40. [9] Varma R, Aronow WS, McClung JA, Garrick R, Vistainer PF, Weiss MB, et al. Prevalence of valve calcium and association of valve calcium with coronary artery disease, atherosclerotic vascular disease, and all-cause mortality in 137 patients undergoing hemodialysis for chronic renal failure. Am J Cardiol 2005;95:742–3. [10] Harpaz D, Auerbach I, Vered Z, Motro M, Tobar A, Rosenblatt S. Caseous calcification of the mitral annulus: a neglected, unrecognized diagnosis. J Am Soc Echocardiogr 2001;14:825–31.
Please cite this article in press as: Takeuchi Y, et al. A rare case of spontaneously dissolved calcification of the mitral annulus: Caseous calcification of the mitral annulus. J Cardiol Cases (2017), https://doi.org/10.1016/j.jccase.2017.11.001