Gen Thorac Cardiovasc Surg DOI 10.1007/s11748-013-0366-6
CASE REPORT
Severe bioprosthetic mitral valve stenosis in pregnancy Jerson Munoz-Mendoza • Veronica Pinto Miranda Tanyanan Tanawuttiwat • Amit Badiye • Sandra V. Chaparro
•
Received: 29 August 2013 / Accepted: 18 December 2013 Ó The Japanese Association for Thoracic Surgery 2013
Abstract A 21-year-old woman in the 16th week of pregnancy was admitted due to acute presentation of severe exertional dyspnea. She had undergone mitral valve replacement (MVR) with bioprosthetic valve for infective endocarditis 2 years ago. She developed congestive heart failure from mitral bioprosthetic valve stenosis due to early structural valve deterioration. She also had severe pulmonary hypertension and underwent a redo MVR using a mechanical valve prosthesis with good maternal outcome but fetal demise. This report brings up the debate about what type of valve should be used in women in reproductive age, and discusses the management of severe mitral stenosis and stenosis of a bioprosthetic valve during pregnancy. Surgical options can almost always be delayed until fetal maturity is achieved and a simultaneous cesarean section can be performed. However, under certain circumstances when the maternal welfare is in jeopardy the surgical intervention is mandatory even before the fetus reaches viability. Keywords Bioprosthesis Pregnancy Mitral stenosis Redo mitral surgery
Electronic supplementary material The online version of this article (doi:10.1007/s11748-013-0366-6) contains supplementary material, which is available to authorized users. J. Munoz-Mendoza (&) V. Pinto Miranda Department of Medicine, University of Miami/Jackson Memorial Hospital, 1611 NW 12th Avenue, Central Building, Room 600D, Miami, FL 33136, USA e-mail: [email protected] T. Tanawuttiwat A. Badiye S. V. Chaparro Division of Cardiology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL 33136, USA
Introduction Physiologic changes during pregnancy can aggravate many valvular conditions including bioprosthesis failure. Structural valve deterioration (SVD) of a bioprosthesis can manifest as stenosis of a bioprosthetic valve. The management of mitral stenosis during pregnancy is always challenging, since it has to balance the fetal and maternal safety. There is limited data regarding the management of stenosis of a bioprosthetic valve in mitral position during pregnancy. Herein, we describe a unique case of pregnancy complicated by bioprosthetic failure and review the current evidence regarding different treatment options.
Case presentation A 21-year-old, gravid 1, 16-week pregnant woman with hepatitis C, bipolar disorder and intravenous drug abuse, was referred from an outside hospital for the management of decompensated heart failure and mitral stenosis. Her initial presentation was worsening shortness of breath and NYHA class III dyspnea for 2 weeks. Two and half years ago, the patient was diagnosed with methicillin-resistant Staphylococcus aureus (MRSA) mitral valve endocarditis and underwent a mitral valve repair. Six months later, she developed another episode of MRSA endocarditis, requiring an emergency mitral valve replacement (MVR) with a 27-mm porcine bioprosthetic valve (Medtronic, Minneapolis, MN, USA). Due to continuous use of illicit intravenous drugs, she subsequently had two more episodes of endocarditis, treated medically. With her poor compliance, she had become pregnant against medical advice. At the outside hospital, the patient was diagnosed with heart failure and treated with intravenous diuretics and beta
123
Gen Thorac Cardiovasc Surg Fig. 1 Continuous Doppler echocardiography demonstrating high pressure gradient across the mitral valve (mean pressure gradient of 44 mmHg)
blockers. Transthoracic echocardiography revealed normal left ventricular systolic function (ejection fraction of 60 %), severe mitral stenosis with thickened prosthetic leaflets and mitral mean pressure gradient of 44 mmHg (Fig. 1). Her right ventricular systolic pressure was 85 mmHg with right ventricular pressure overload, evidenced by a flattened septum during systole. Transesophageal echocardiography showed well-seated mitral prosthetic valve, homogenously thickened with restricted motion of mitral leaflet (Fig. 2, Videos 1 and 2). The 3D planimetry showed mitral valve area of 0.15 cm2. There was no mitral regurgitation and neither vegetation nor thrombus was seen on the prosthetic mitral valve. After 5 days of diuretics and beta blockers, the patient’s symptoms improved. Nonetheless, given the severity of the mitral valve stenosis, it was foreseen that her condition will deteriorate as her pregnancy advances and it was considered very high-risk pregnancy. A multidisciplinary team including Obstetrics, Cardiology, Anesthesia and Cardiothoracic Surgery recommended the patient to undergo redo MVR despite the ominous prognosis for fetal survival. Since the mother’s well-being was the first priority, in the setting of a non-viable pregnancy, the final decision was to pursue surgery. Importantly, the risk and benefits of the surgery for the mother and the fetus, along with the implications in terms of care after mechanical valve implantation were discussed at length with the patient and her fiance´. During surgery, continuous fetal heart rate monitoring was performed using an external ultrasound transducer for the duration of the procedure. One dose of
123
Fig. 2 Three-dimensional echocardiography demonstrating thickening and restricted motion of structure deteriorated mitral bioprostheses from left atrial view (Video 1)
antegrade cold blood cardioplegia was given to achieve a rapid diastolic arrest before opening the atrium. Intraoperatively, mitral bioprosthetic valve was found largely stenotic and contracted; however, no thrombus was identified in the left atrium or the left ventricle. A mitral valve replacement was performed using a 25-mm St. Jude Medical standard (model MECJ-502) mechanical mitral valve prostheses (SJM, St Paul, MN, USA). She then developed transient hypotension, requiring 4 different pressors/inotropes to maintain a median arterial pressure over 70 mmHg. This regimen included milrinone 0.5 mcg/
Gen Thorac Cardiovasc Surg
Fig. 3 Hemotoxylin and Eosin (H&E) stain in this figure shows extensive calcification and degeneration of the prosthetic valve. Fragments of prosthetic valve are largely replaced by fibrous collagen band admixed with calcification (white arrows)
kg/min, norepinephrine 10 mcg/min, epinephrine 2 mcg/ min, and vasopressin 0.04 units/min intravenously. A fetal demise was documented during the procedure. The cardiopulmonary bypass (CBP) time was 145 min, and flow during CPB was 4–5 L min-1. Her postoperative course was uneventful. Histopathological findings of the valve demonstrated fibrocalcific disease of the valve with mural thrombi (Fig. 3). These findings were consistent with SVD. She underwent curettage procedure of missed abortion 4 days later. There was no complication associated with the procedures, the patient recovered well, and was discharged home 5 days after surgery. She would follow-up in the cardiology and anticoagulation clinics.
Discussion Our patient’s mitral bioprosthesis developed an accelerated SVD after 25 months of implantation, likely as a consequence of two episodes of endocarditis resulting in severe stenosis of the bioprosthetic mitral valve. The controversy regarding the influence of pregnancy on SVD started in the 1980s when the initial reports suggested accelerated valve deterioration during pregnancy [1]; however, a growing body of evidence since mid-1990s has not confirmed this phenomenon. The largest study which involved 237 women in reproductive age recluted from four centers in USA and Canada sought the rates of SVD in women who experienced pregnancy and in women who were never pregnant and demonstrated that the rates of SVD and freedom from SVD at 10 and 15 years, respectively, were not significantly different in these two groups [2]. The latest study performed in 33
women in reproductive age also showed that freedom from valve replacement at 5 and 10 years was similar in women who experienced pregnancy versus the ones who were never pregnant, respectively [3]. It is likely that the initial reports may have simply reflected the well-established-accelerated bioprosthesis deterioration that occurs in younger patients [1]. Therefore, in light of the current evidence available we can establish that pregnancy may have not played a role in the degeneration of our patient’s bioprosthetic mitral valve. Currently, there is still debate about what would be the valve of choice for women of childbearing age. Bioprosthetic valves do not require anticoagulation but their most common cause of failure is SVD, which manifests mainly as stenosis of the bioprosthetic valve. Mechanical valves are usually preferred because of their longer durability [4]; however, it requires adherence with long-standing oral anticoagulation with coumadin and continuous monitoring of INR to prevent valve thrombosis. In addition, when a patient gets pregnant, deciding for the best anticoagulation regimen is always challenging especially in the absence of randomized controlled trials [4–6]. Coumadin is associated with abortion, stillbirths, central nervous system and eyes abnormalities, and of course, warfarin embryopathy if it is taken during the 6th and 12th weeks of pregnancy (characterized by nasal hypoplasia and/or stippled epiphyses) [6]; however, it is superior to unfractionated and low molecular weight heparin in preventing thromboembolic effects [4]. Moreover, anticoagulation in general is associated with increased risk of bleeding during delivery [5]. It is highly probable that all these considerations were made while choosing the type of prosthesis by the time of the initial mitral valve replacement in an outside facility, as they were also considered by our team at the time of the redo surgery. Finally, she opted for a mechanical valve the second time as she was willing to take oral anticoagulants and be adherent to clinic appointments. For pregnant patients with severe stenosis of native mitral valve who develop NYHA functional class III–IV symptoms or systolic pulmonary artery pressure [50 mmHg despite medical therapy, current guidelines recommend percutaneous mitral balloon valvuloplasty (PMBV) if the valve is anatomically suitable; otherwise, they should undergo open heart surgery, which should be delayed until the time the fetus is viable and a cesarean section can be performed as part of a concomitant procedure [7, 8]. In a series of 71 patients who underwent valvuloplasty of a native valve during pregnancy, the restenosis-free rate was 70 % at 87 months, and 90 % of the patients were free of surgical intervention at 48 months [9]. Experience on PMBV for native valves is extensive [10], but for bioprosthetic valves is limited. There are no clinical trials; indeed, only fifteen cases of balloon
123
Gen Thorac Cardiovasc Surg
valvuloplasty for degenerated bioprosthetic valve in mitral position have been reported [11]; however, none of them in pregnant population. Given the limited data of PMBV in pregnant population, and the fact that our patient’s bioprosthetic mitral valve became thickened and calcified leading to severe stenosis, she was not suitable for balloon valvuloplasty and redo mitral valve replacement was pursued. For pregnant patients with mitral stenosis, the increase in the intravascular volume by 30 to 50 % over nonpregnant levels may result in an increase in the transmitral gradient and left atrial pressure and lead to acute pulmonary edema, with worsening of symptoms in the third trimester and during delivery [6]. Our patient already had severe pulmonary hypertension at 16 weeks of pregnancy and it was clear that she would not certainly tolerate the hemodynamic burden of pregnancy, labor and delivery. The presence of mitral stenosis increases the maternal and fetal mortality by 9 and 30 % [6], respectively, particularly when there are advanced heart failure symptoms (NYHA class III–IV), like our patient. In addition, general anesthesia, thoracotomy and cardiopulmonary bypass are risk factors for fetal mortality [12]; maternal and fetal mortality during mitral valve surgery throughout pregnancy are 9 and 29 %, respectively [4], whereas PMVB success rate is 95 % [13], with mortality rates are less than 2 % for both child and mother [9]. Our patient underwent redo sternotomy and replacement of the mitral valve with a mechanical valve, requiring the use of cardiopulmonary bypass. With the current use of extracorporeal circulation techniques, maternal outcomes are similar to those in non-pregnant women (3–15 %) [14], but the incidence of fetal loss remains high (10–40 %) [13], due to low placental perfusion pressures, acidosis and hypocapnia, which are responsible for uteroplacental vasoconstriction and fetal hypoxia [14]. The features of CPB that are optimal to improve fetal survival are still to be determined, but a recent revision of 14 papers constituting the best evidence available concluded that the use of high-flow, high pressure, pulsatile, normothermic bypass and fetal and uterine monitoring can allow cardiac surgery with the use of CPB to be performed with the greatest control of risk in the pregnant patient [15]. Our patient had transient hypotension that required 4 different drugs to maintain a mean arterial pressure (MAP) [70, which most probably lead to placental hypoperfusion and fetal demise. Bradycardia is the most frequent fetal response to CPB, most likely because of hypoperfusion [14]. In conclusion, this case illustrates an early structural valve deterioration of a bioprosthesis, likely triggered by two episodes of infective endocarditis after intravenous drug abuse, which became symptomatic during
123
pregnancy, leading to a redo valve replacement at second trimester with patient survival but fetal demise. This case also highlights the need of prenatal counseling of woman with prosthetic valves in reproductive age and the need of more evidence for the management of stenosis of bioprosthetic valves during pregnancy. Acknowledgments We would like to thank Dr. Yu Wendong for his collaboration in histopathological image annotation and Dr. Martin S. Bilsker for his support in echocardiographic imaging. Conflict of interest
None declared.
References 1. Elkayam U, Bitar F. Valvular heart disease and pregnancy: part II: prosthetic valves. J Am Coll Cardiol. 2005;46(3):403–10. 2. Jamieson WRE, Miller DC, Akins CW, Munro AI, Glower DD, Moore KA, et al. Pregnancy and bioprosthesis: influence of structural valve deterioration. Ann Thorac Surg. 1995;60:S282–7. 3. Cleuziou J, Horer J, Kaemmerer H, Teodorowicz A, KasnarSamprec J, Schreiber C, et al. Pregnancy does not accelerate biological valve degeneration. Int J Cardiol. 2010;145:418–21. 4. Scirica BM, O’Gara PT. Valvular heart disease in pregnancy. Curr Cardiol Rep. 2006;8:83–9. 5. Chang WS, Anand S, Ginsberg JF. Antioagulation of pregnant women with mechanical valves. Arch Intern Med. 2000;160:191–6. 6. Reimold SC, Rutherford JD. Valvular heart disease in pregnancy. N Engl J Med. 2003;349:52–9. 7. ACC/AHA 2006 Guidelines for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 1998 Guidelines for the Management of Patients With Valvular Heart Disease): Developed in Collaboration With the Society of Cardiovascular Anesthesiologists: Endorsed by the Society for Cardiovascular Angiography and Interventions and the Society of Thoracic Surgeons. Circulation. 2006;114:450–527. 8. European Society of Gynecology (ESG), Association for European Paediatric Cardiology (AEPC), German Society for Gender Medicine (DGesGM), ESC Committee for Practice Guidelines. ESC Guidelines on the management of cardiovascular diseases during pregnancy: the task force on the management of cardiovascular diseases during pregnancy of the European Society of Cardiology (ESC). Eur Heart J. 2011;32(24):3147–97. 9. Norrad RS, Salehian O. Management of severe mitral stenosis during pregnancy. Circulation. 2011;124:2756–60. 10. Nobuyoshi M, Arita T, Shirai SI, Hamasaki N, Yokoi H, Iwabuchi M, et al. Percutaneous balloon mitral valvuloplasty. Circulation. 2009;119:e211–9. 11. Hamatani Y, Saito N, Tazaki J, Natsuaki M, Nakai K, Makiyama T, et al. Percutaneous balloon valvuloplasty for bioprosthetic mitral valve stenosis. Heart Vessels. 2012. doi 10.1007/s00380012-0309-7. (Epub ahead of print). 12. Cunha CR, Santos PC, Castineira CP, Pereira FSF. Heart valve replacement during pregnancy. Rev Bras Cir Cardiovasc. 2007;22(4):498–500. 13. Hameed AB, Mehra A, Rahimtoola S. The role of catheter balloon commissurotomy for severe mitral stenosis in pregnancy. Obstet Gynecol. 2009;114:1336–40.
Gen Thorac Cardiovasc Surg 14. Lin TY, Ciu KM, Shieh JS, Chu SH. Emergency redo mitral valve replacement in a pregnant woman at third trimester. Cir J. 2008;72(10):1715-7.
15. Sepehripour AH, Lo TT, Shipolini AR, McCormack DJ. Can pregnant women be safely placed on cardiopulmonary bypass? Interact CardioVasc Thorac Surg. 2012;15:1063–71.
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CASE REPORT
Severe bioprosthetic mitral valve stenosis in pregnancy Jerson Munoz-Mendoza • Veronica Pinto Miranda Tanyanan Tanawuttiwat • Amit Badiye • Sandra V. Chaparro
•
Received: 29 August 2013 / Accepted: 18 December 2013 Ó The Japanese Association for Thoracic Surgery 2013
Abstract A 21-year-old woman in the 16th week of pregnancy was admitted due to acute presentation of severe exertional dyspnea. She had undergone mitral valve replacement (MVR) with bioprosthetic valve for infective endocarditis 2 years ago. She developed congestive heart failure from mitral bioprosthetic valve stenosis due to early structural valve deterioration. She also had severe pulmonary hypertension and underwent a redo MVR using a mechanical valve prosthesis with good maternal outcome but fetal demise. This report brings up the debate about what type of valve should be used in women in reproductive age, and discusses the management of severe mitral stenosis and stenosis of a bioprosthetic valve during pregnancy. Surgical options can almost always be delayed until fetal maturity is achieved and a simultaneous cesarean section can be performed. However, under certain circumstances when the maternal welfare is in jeopardy the surgical intervention is mandatory even before the fetus reaches viability. Keywords Bioprosthesis Pregnancy Mitral stenosis Redo mitral surgery
Electronic supplementary material The online version of this article (doi:10.1007/s11748-013-0366-6) contains supplementary material, which is available to authorized users. J. Munoz-Mendoza (&) V. Pinto Miranda Department of Medicine, University of Miami/Jackson Memorial Hospital, 1611 NW 12th Avenue, Central Building, Room 600D, Miami, FL 33136, USA e-mail: [email protected] T. Tanawuttiwat A. Badiye S. V. Chaparro Division of Cardiology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL 33136, USA
Introduction Physiologic changes during pregnancy can aggravate many valvular conditions including bioprosthesis failure. Structural valve deterioration (SVD) of a bioprosthesis can manifest as stenosis of a bioprosthetic valve. The management of mitral stenosis during pregnancy is always challenging, since it has to balance the fetal and maternal safety. There is limited data regarding the management of stenosis of a bioprosthetic valve in mitral position during pregnancy. Herein, we describe a unique case of pregnancy complicated by bioprosthetic failure and review the current evidence regarding different treatment options.
Case presentation A 21-year-old, gravid 1, 16-week pregnant woman with hepatitis C, bipolar disorder and intravenous drug abuse, was referred from an outside hospital for the management of decompensated heart failure and mitral stenosis. Her initial presentation was worsening shortness of breath and NYHA class III dyspnea for 2 weeks. Two and half years ago, the patient was diagnosed with methicillin-resistant Staphylococcus aureus (MRSA) mitral valve endocarditis and underwent a mitral valve repair. Six months later, she developed another episode of MRSA endocarditis, requiring an emergency mitral valve replacement (MVR) with a 27-mm porcine bioprosthetic valve (Medtronic, Minneapolis, MN, USA). Due to continuous use of illicit intravenous drugs, she subsequently had two more episodes of endocarditis, treated medically. With her poor compliance, she had become pregnant against medical advice. At the outside hospital, the patient was diagnosed with heart failure and treated with intravenous diuretics and beta
123
Gen Thorac Cardiovasc Surg Fig. 1 Continuous Doppler echocardiography demonstrating high pressure gradient across the mitral valve (mean pressure gradient of 44 mmHg)
blockers. Transthoracic echocardiography revealed normal left ventricular systolic function (ejection fraction of 60 %), severe mitral stenosis with thickened prosthetic leaflets and mitral mean pressure gradient of 44 mmHg (Fig. 1). Her right ventricular systolic pressure was 85 mmHg with right ventricular pressure overload, evidenced by a flattened septum during systole. Transesophageal echocardiography showed well-seated mitral prosthetic valve, homogenously thickened with restricted motion of mitral leaflet (Fig. 2, Videos 1 and 2). The 3D planimetry showed mitral valve area of 0.15 cm2. There was no mitral regurgitation and neither vegetation nor thrombus was seen on the prosthetic mitral valve. After 5 days of diuretics and beta blockers, the patient’s symptoms improved. Nonetheless, given the severity of the mitral valve stenosis, it was foreseen that her condition will deteriorate as her pregnancy advances and it was considered very high-risk pregnancy. A multidisciplinary team including Obstetrics, Cardiology, Anesthesia and Cardiothoracic Surgery recommended the patient to undergo redo MVR despite the ominous prognosis for fetal survival. Since the mother’s well-being was the first priority, in the setting of a non-viable pregnancy, the final decision was to pursue surgery. Importantly, the risk and benefits of the surgery for the mother and the fetus, along with the implications in terms of care after mechanical valve implantation were discussed at length with the patient and her fiance´. During surgery, continuous fetal heart rate monitoring was performed using an external ultrasound transducer for the duration of the procedure. One dose of
123
Fig. 2 Three-dimensional echocardiography demonstrating thickening and restricted motion of structure deteriorated mitral bioprostheses from left atrial view (Video 1)
antegrade cold blood cardioplegia was given to achieve a rapid diastolic arrest before opening the atrium. Intraoperatively, mitral bioprosthetic valve was found largely stenotic and contracted; however, no thrombus was identified in the left atrium or the left ventricle. A mitral valve replacement was performed using a 25-mm St. Jude Medical standard (model MECJ-502) mechanical mitral valve prostheses (SJM, St Paul, MN, USA). She then developed transient hypotension, requiring 4 different pressors/inotropes to maintain a median arterial pressure over 70 mmHg. This regimen included milrinone 0.5 mcg/
Gen Thorac Cardiovasc Surg
Fig. 3 Hemotoxylin and Eosin (H&E) stain in this figure shows extensive calcification and degeneration of the prosthetic valve. Fragments of prosthetic valve are largely replaced by fibrous collagen band admixed with calcification (white arrows)
kg/min, norepinephrine 10 mcg/min, epinephrine 2 mcg/ min, and vasopressin 0.04 units/min intravenously. A fetal demise was documented during the procedure. The cardiopulmonary bypass (CBP) time was 145 min, and flow during CPB was 4–5 L min-1. Her postoperative course was uneventful. Histopathological findings of the valve demonstrated fibrocalcific disease of the valve with mural thrombi (Fig. 3). These findings were consistent with SVD. She underwent curettage procedure of missed abortion 4 days later. There was no complication associated with the procedures, the patient recovered well, and was discharged home 5 days after surgery. She would follow-up in the cardiology and anticoagulation clinics.
Discussion Our patient’s mitral bioprosthesis developed an accelerated SVD after 25 months of implantation, likely as a consequence of two episodes of endocarditis resulting in severe stenosis of the bioprosthetic mitral valve. The controversy regarding the influence of pregnancy on SVD started in the 1980s when the initial reports suggested accelerated valve deterioration during pregnancy [1]; however, a growing body of evidence since mid-1990s has not confirmed this phenomenon. The largest study which involved 237 women in reproductive age recluted from four centers in USA and Canada sought the rates of SVD in women who experienced pregnancy and in women who were never pregnant and demonstrated that the rates of SVD and freedom from SVD at 10 and 15 years, respectively, were not significantly different in these two groups [2]. The latest study performed in 33
women in reproductive age also showed that freedom from valve replacement at 5 and 10 years was similar in women who experienced pregnancy versus the ones who were never pregnant, respectively [3]. It is likely that the initial reports may have simply reflected the well-established-accelerated bioprosthesis deterioration that occurs in younger patients [1]. Therefore, in light of the current evidence available we can establish that pregnancy may have not played a role in the degeneration of our patient’s bioprosthetic mitral valve. Currently, there is still debate about what would be the valve of choice for women of childbearing age. Bioprosthetic valves do not require anticoagulation but their most common cause of failure is SVD, which manifests mainly as stenosis of the bioprosthetic valve. Mechanical valves are usually preferred because of their longer durability [4]; however, it requires adherence with long-standing oral anticoagulation with coumadin and continuous monitoring of INR to prevent valve thrombosis. In addition, when a patient gets pregnant, deciding for the best anticoagulation regimen is always challenging especially in the absence of randomized controlled trials [4–6]. Coumadin is associated with abortion, stillbirths, central nervous system and eyes abnormalities, and of course, warfarin embryopathy if it is taken during the 6th and 12th weeks of pregnancy (characterized by nasal hypoplasia and/or stippled epiphyses) [6]; however, it is superior to unfractionated and low molecular weight heparin in preventing thromboembolic effects [4]. Moreover, anticoagulation in general is associated with increased risk of bleeding during delivery [5]. It is highly probable that all these considerations were made while choosing the type of prosthesis by the time of the initial mitral valve replacement in an outside facility, as they were also considered by our team at the time of the redo surgery. Finally, she opted for a mechanical valve the second time as she was willing to take oral anticoagulants and be adherent to clinic appointments. For pregnant patients with severe stenosis of native mitral valve who develop NYHA functional class III–IV symptoms or systolic pulmonary artery pressure [50 mmHg despite medical therapy, current guidelines recommend percutaneous mitral balloon valvuloplasty (PMBV) if the valve is anatomically suitable; otherwise, they should undergo open heart surgery, which should be delayed until the time the fetus is viable and a cesarean section can be performed as part of a concomitant procedure [7, 8]. In a series of 71 patients who underwent valvuloplasty of a native valve during pregnancy, the restenosis-free rate was 70 % at 87 months, and 90 % of the patients were free of surgical intervention at 48 months [9]. Experience on PMBV for native valves is extensive [10], but for bioprosthetic valves is limited. There are no clinical trials; indeed, only fifteen cases of balloon
123
Gen Thorac Cardiovasc Surg
valvuloplasty for degenerated bioprosthetic valve in mitral position have been reported [11]; however, none of them in pregnant population. Given the limited data of PMBV in pregnant population, and the fact that our patient’s bioprosthetic mitral valve became thickened and calcified leading to severe stenosis, she was not suitable for balloon valvuloplasty and redo mitral valve replacement was pursued. For pregnant patients with mitral stenosis, the increase in the intravascular volume by 30 to 50 % over nonpregnant levels may result in an increase in the transmitral gradient and left atrial pressure and lead to acute pulmonary edema, with worsening of symptoms in the third trimester and during delivery [6]. Our patient already had severe pulmonary hypertension at 16 weeks of pregnancy and it was clear that she would not certainly tolerate the hemodynamic burden of pregnancy, labor and delivery. The presence of mitral stenosis increases the maternal and fetal mortality by 9 and 30 % [6], respectively, particularly when there are advanced heart failure symptoms (NYHA class III–IV), like our patient. In addition, general anesthesia, thoracotomy and cardiopulmonary bypass are risk factors for fetal mortality [12]; maternal and fetal mortality during mitral valve surgery throughout pregnancy are 9 and 29 %, respectively [4], whereas PMVB success rate is 95 % [13], with mortality rates are less than 2 % for both child and mother [9]. Our patient underwent redo sternotomy and replacement of the mitral valve with a mechanical valve, requiring the use of cardiopulmonary bypass. With the current use of extracorporeal circulation techniques, maternal outcomes are similar to those in non-pregnant women (3–15 %) [14], but the incidence of fetal loss remains high (10–40 %) [13], due to low placental perfusion pressures, acidosis and hypocapnia, which are responsible for uteroplacental vasoconstriction and fetal hypoxia [14]. The features of CPB that are optimal to improve fetal survival are still to be determined, but a recent revision of 14 papers constituting the best evidence available concluded that the use of high-flow, high pressure, pulsatile, normothermic bypass and fetal and uterine monitoring can allow cardiac surgery with the use of CPB to be performed with the greatest control of risk in the pregnant patient [15]. Our patient had transient hypotension that required 4 different drugs to maintain a mean arterial pressure (MAP) [70, which most probably lead to placental hypoperfusion and fetal demise. Bradycardia is the most frequent fetal response to CPB, most likely because of hypoperfusion [14]. In conclusion, this case illustrates an early structural valve deterioration of a bioprosthesis, likely triggered by two episodes of infective endocarditis after intravenous drug abuse, which became symptomatic during
123
pregnancy, leading to a redo valve replacement at second trimester with patient survival but fetal demise. This case also highlights the need of prenatal counseling of woman with prosthetic valves in reproductive age and the need of more evidence for the management of stenosis of bioprosthetic valves during pregnancy. Acknowledgments We would like to thank Dr. Yu Wendong for his collaboration in histopathological image annotation and Dr. Martin S. Bilsker for his support in echocardiographic imaging. Conflict of interest
None declared.
References 1. Elkayam U, Bitar F. Valvular heart disease and pregnancy: part II: prosthetic valves. J Am Coll Cardiol. 2005;46(3):403–10. 2. Jamieson WRE, Miller DC, Akins CW, Munro AI, Glower DD, Moore KA, et al. Pregnancy and bioprosthesis: influence of structural valve deterioration. Ann Thorac Surg. 1995;60:S282–7. 3. Cleuziou J, Horer J, Kaemmerer H, Teodorowicz A, KasnarSamprec J, Schreiber C, et al. Pregnancy does not accelerate biological valve degeneration. Int J Cardiol. 2010;145:418–21. 4. Scirica BM, O’Gara PT. Valvular heart disease in pregnancy. Curr Cardiol Rep. 2006;8:83–9. 5. Chang WS, Anand S, Ginsberg JF. Antioagulation of pregnant women with mechanical valves. Arch Intern Med. 2000;160:191–6. 6. Reimold SC, Rutherford JD. Valvular heart disease in pregnancy. N Engl J Med. 2003;349:52–9. 7. ACC/AHA 2006 Guidelines for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 1998 Guidelines for the Management of Patients With Valvular Heart Disease): Developed in Collaboration With the Society of Cardiovascular Anesthesiologists: Endorsed by the Society for Cardiovascular Angiography and Interventions and the Society of Thoracic Surgeons. Circulation. 2006;114:450–527. 8. European Society of Gynecology (ESG), Association for European Paediatric Cardiology (AEPC), German Society for Gender Medicine (DGesGM), ESC Committee for Practice Guidelines. ESC Guidelines on the management of cardiovascular diseases during pregnancy: the task force on the management of cardiovascular diseases during pregnancy of the European Society of Cardiology (ESC). Eur Heart J. 2011;32(24):3147–97. 9. Norrad RS, Salehian O. Management of severe mitral stenosis during pregnancy. Circulation. 2011;124:2756–60. 10. Nobuyoshi M, Arita T, Shirai SI, Hamasaki N, Yokoi H, Iwabuchi M, et al. Percutaneous balloon mitral valvuloplasty. Circulation. 2009;119:e211–9. 11. Hamatani Y, Saito N, Tazaki J, Natsuaki M, Nakai K, Makiyama T, et al. Percutaneous balloon valvuloplasty for bioprosthetic mitral valve stenosis. Heart Vessels. 2012. doi 10.1007/s00380012-0309-7. (Epub ahead of print). 12. Cunha CR, Santos PC, Castineira CP, Pereira FSF. Heart valve replacement during pregnancy. Rev Bras Cir Cardiovasc. 2007;22(4):498–500. 13. Hameed AB, Mehra A, Rahimtoola S. The role of catheter balloon commissurotomy for severe mitral stenosis in pregnancy. Obstet Gynecol. 2009;114:1336–40.
Gen Thorac Cardiovasc Surg 14. Lin TY, Ciu KM, Shieh JS, Chu SH. Emergency redo mitral valve replacement in a pregnant woman at third trimester. Cir J. 2008;72(10):1715-7.
15. Sepehripour AH, Lo TT, Shipolini AR, McCormack DJ. Can pregnant women be safely placed on cardiopulmonary bypass? Interact CardioVasc Thorac Surg. 2012;15:1063–71.
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