Correspondence

Outcomes after Heart-Valve Replacement

N Engl J Med 1993; 329:1278October 21, 1993

Article

To the Editor:

In their comparison of outcomes in men 11 years after heart-valve replacement with a mechanical valve or bioprosthesis, Hammermeister et al. (May 6 issue)1 found a mortality rate of approximately 25 percent among patients requiring reoperation. The mortality rate reported for the Edinburgh Heart Valve Trial2 (30 percent) is incorrect; the rate was in fact 19 percent. In recent years the mortality rate has improved at our institution3. The overall figure for the United Kingdom in 1989 was 12.9 percent.

We believe that the risk of death at reoperation after heart-valve replacement and the increased morbidity should temper the authors' recommendation that “Because of the teratogenic effect of warfarin, women who desire to become pregnant should receive a bioprosthesis, provided they are willing to accept a high probability of reoperation 10 years or more after valve replacement”1. Oakley4 has argued cogently that valve replacement should be delayed if at all possible until after pregnancy, with mitral valvotomy as an initial surgical option. She has also argued that the teratogenic effects of warfarin may have been overestimated and that many patients will require anticoagulation in any case because of atrial fibrillation. The risk of death at reoperation in a young mother cannot be lightly dismissed.

Peter Bloomfield, M.D., F.R.C.P.
David J. Wheatley, M.D., F.R.C.S.
Hugh C. Miller, F.R.C.P.
Royal Infirmary of Edinburgh, Edinburgh EH3 9YW, United Kingdom

4 References

1. 1

   Hammermeister KE, Sethi GK, Henderson WG, Oprian C, Kim T, Rahimtoola S. A comparison of outcomes in men 11 years after heart-valve replacement with a mechanical valve or bioprosthesis. N Engl J Med 1993;328:1289-1296
   Full Text | Web of Science | Medline

2. 2

   Bloomfield P, Wheatley DJ, Prescott RJ, Miller HC. Twelve-year comparison of a Bjork-Shiley mechanical heart valve with porcine bioprostheses. N Engl J Med 1991;324:573-579
   Full Text | Web of Science | Medline

3. 3

   Bloomfield P, Wheatley DJ, Miller HC, Prescott RJ. Selection of an artificial heart valve. N Engl J Med 1991;325:433-433
   Web of Science

4. 4

   Oakley C. Valve prostheses and pregnancy. Br Heart J 1987;58:303-305
   CrossRef | Web of Science | Medline

Author/Editor Response

The authors reply:

To the Editor: Most of the differences in findings between the Edinburgh Heart Valve Trial and the Veterans Affairs Cooperative Study on Valvular Heart Disease are the result of differences in patient populations. The younger patients and the large proportion of women in the Edinburgh trial would be expected to result in a higher failure rate for bioprosthetic valves. The difference in the intensity of anticoagulation explains the higher rate of bleeding in the Veterans Affairs trial.

In regard to clinical implications, we believe that there are more areas of agreement than disagreement. Both groups of investigators concluded that most patients undergoing mitral-valve replacement should receive a mechanical prosthesis because of the high failure rate of bioprostheses in this position, and that bioprostheses might be used in older patients undergoing aortic-valve replacement. Although it is likely that we differ about the overall role of bioprosthetic valves in our respective practices (we would favor a larger role for bioprostheses than the Edinburgh group), this difference is largely justified by the nature of the patients for whom we care. The choice of valve should be an individual decision made for each patient on the basis of the data from these two randomized trials and many other studies,1 the physician's knowledge of the patient, the outcomes of valve replacement in the physician's practice, and the patient's desires after he or she is informed of the risks and benefits of the use of the two types of valves. In brief, we believe it is very important to match the valve to the patient.1

We acknowledge and apologize for the error in reporting the mortality rate among patients requiring reoperation in the Edinburgh trial.

K.E. Hammermeister, M.D.
Gulshan K. Sethi, M.D.
Veterans Affairs Medical Center, Denver, CO 80220

1 References

1. 1

   Grunkemeier GL, Starr A, Rahimtoola SH. Prosthetic heart valve performance: long-term follow-up. Curr Probl Cardiol 1992;17:329-406
   Web of Science | Medline