Editorial

Does pregnancy affect the durability of valvularbioprostheses?Donald D. Glower, MD Durham, NC

Pregnancy and valve replacement are two events thatmost physicians seldom encounter in the same patient.As a result, definitive data regarding the effect of preg-nancy on the durability of bioprostheses are scant, andanecdotal reports of early failure of biological heartvalves in pregnant patients tends to raise concerns. Inthis issue, Salazar et al1 present data from 48 womenwho became pregnant after bovine pericardial valvereplacement.Their data confirm recent reports thatpregnancy does not significantly affect durability of bio-prostheses.

The article by Salazar et al1 reports the largest single-institution study examining the issue of pregnancy andvalve durability.The results provide important confirma-tion of a larger multi-institutional study finding no effectof pregnancy on the durability of bioprostheses.2 Thearticle also provides detailed and valuable data regardingthe outcome from pregnancy in patients with prostheticheart valves and from pregnant patients receiving anti-coagulation.

This study has several limitations.First, the number ofpatients is relatively small, although probably largeenough to detect any clinically significant effects of preg-nancy on valve durability. Second, the study is limited tothe hard end points of death and reoperation.Conceiv-ably,pregnancy could cause more subtle valvular dysfunc-tion not detected by analysis of death or reoperation.More subtle valvular dysfunction awaits further investiga-tion but does not appear to be an obvious concern.Finally, the biologic valve used in this study is a first-gener-ation pericardial bioprosthesis manufactured locally inMexico City.Yet, the durability of the prosthesis used iscomparable to that observed with other pericardial pros-theses or porcine mitral prostheses.3,4 Furthermore, thereis little reason to suspect that other bioprostheses mightbe more susceptible to pregnancy-induced deteriorationthan the device used in this study.

The primary implication of the study is that biopros-theses remain a very reasonable alternative for youngwomen who desire the option of pregnancy after valve

replacement.Although limited, current data suggest thatthe risks of fetal loss, hemorrhage, prolonged hospitaliza-tion, and possibly teratogenesis associated with mechan-ical valve replacement and anticoagulation during preg-nancy remain considerable.1

A second issue demonstrated but not addressed bythis study is management of anticoagulation in pregnantpatients with bioprostheses.Anticoagulation is often rec-ommended after biological mitral valve replacementeither chronically in patients with atrial fibrillation orearly after operation in all patients.5 Nonetheless, Blairet al6 showed that aspirin alone can minimize early post-operative thromboembolism after biologic aortic valvereplacement in most patients and after biologic mitralvalve replacement in patients in sinus rhythm. For thosepatients with chronic atrial fibrillation after biologicmitral valve replacement, the risks of thromboembolismwhile receiving aspirin alone may be as low as 1.6% to1.9% per patient-year,6,7 which compares favorably tothe morbidity of anticoagulation during pregnancy.1

Another issue not addressed by Salazar et al1 is therole of mitral valve repair either by open heart opera-tion or by percutaneous balloon valvuloplasty in youngwomen desiring pregnancy. Most young women requir-ing valve operation have rheumatic heart disease.Although the long-term results from balloon valvulo-plasty or mitral repair for rheumatic mitral valve dis-ease are not as good as after mechanical valve replace-ment,8,9 the results have generally been comparable tothose after biological mitral valve replacement in theyounger age group.2,3 Mitral valve repair or replace-ment with mitral valve homograft tissue is anotherpotential option for these patients to avoid anticoagu-lation.10 One drawback to mitral valvuloplasty in theseyoung rheumatic patients is less predictable durabilityof the procedure relative to the durability of a manu-factured bioprosthesis.9

Salazar et al1 confirm the current consensus thatpregnancy does not affect the durability of biopros-theses to any significant degree. Bioprostheses there-fore remain the devices of choice for young womenwilling to trade earlier reoperation for the opportunityof pregnancy. Issues to be settled include whetherpregnancy might cause more subtle dysfunction ofbioprostheses detectable only by echocardiographyand whether newer forms of percutaneous or opera-tive mitral valve repair might be underutilized optionsin these patients.

From Duke University Medical Center.Reprint requests: Donald D. Glower, MD, Box 3810, Duke University Medical Cen-ter, Durham, NC 27710.Am Heart J 1999;137:590-1.0002-8703/99/$8.00 + 0 4/1/93203

See related article on page 714.

American Heart JournalVolume 137, Number 4, Part 1 Glower 591

References1. Salazar E, Espinola N, Romain L, et al. Effect of pregnancy on the dura-

tion of bovine pericardial bioprostheses. Am Heart J 1999;137:714-20.2. Jamieson WRE, Miller DC, Akins CW, et al. Pregnancy and biopros-

theses: influence on structural valve deterioration. Ann Thorac Surg1995;60:5282-7.

3. Glower DD, White WD, Hatton AC, et al. Determinants of reopera-tion after 960 valve replacements with Carpentier-Edwards prosthe-ses. J Thorac Cardiovasc Surg 1994;107:381-93.

4. Meyns B, Szecsi J, Flameng W, et al. Aortic and mitral valvereplacement with the Carpentier-Edwards pericardial bioprosthesis:mid-term clinical results. J Heart Valve Dis 1994;3:66-70.

5. Carpentier A, Dubost C, Lane E, et al. Continuing improvements invalvular bioprostheses. J Thorac Cardiovasc Surg 1982;83:27-42.

6. Blair KL, Hatton AC, White WD, et al. Comparison of anticoagula-

tion regimens following Carpentier-Edwards aortic or mitral valvereplacement. Circulation 1994;90(suppl II):214-9.

7. Nunez L, Aguado MG, Larrea JL, et al. Prevention of thromboem-bolism using aspirin after mitral valve replacement with porcine bio-prosthesis. Ann Thorac Surg 1984;37:84-7.

8. Cohen JM, Glower DD, Harrison JK, et al. Comparison of percuta-neous balloon valvuloplasty and open commissurotomy in 90consecutive patients with mitral stenosis. Ann Thorac Surg 1993;56:1254-62.

9. Deloche A, Jebara VA, Relland JY, et al. Valve repair with Carpen-tier techniques: the second decade. J Thorac Cardiovasc Surg1990;99:990-1001.

10. Acar C, Tolan M, Berrebi A, et al. Homograft replacement of themitral valve: graft selection, technique of implantation, and results in43 patients. J Thorac Cardiovasc Surg 1996;111:367-78.