14th Artificial Heart Patient Dies: A Newsmaker Interview With Robert Kung, PhD

Laurie Barclay, MD

November 11, 2004

Nov. 11, 2004 — Editor's Note: On Nov. 4, the fourteenth recipient of Abiomed Inc.'s AbioCor implantable artificial heart died of multiorgan failure after living with the experimental device for 166 days, despite anticipated survival without treatment of fewer than 30 days. During his treatment at Jewish Hospital in Louisville, Kentucky, the artificial heart worked well and without any evidence of malfunction or device failure.

In September, Abiomed applied for initial U.S. Food and Drug Administration marketing approval under a humanitarian device exemption for AbioCor to be used in a clinical trial with a well-defined group of patients suffering from irreversible end-stage heart failure. Eligibility criteria for the AbioCor clinical trial are biventricular heart failure, ineligibility for heart transplantation, failure of other available therapy, and high risk of death in fewer than 30 days. The AbioCor has not been approved for commercial distribution, and it is not available for use or sale outside of the initial clinical trial.

To learn more about the experience to date with this device and its potential for more widespread use, Medscape's Laurie Barclay interviewed Robert Kung, PhD, chief scientific officer of Abiomed, located in Danvers, Massachusetts.

Medscape: What was the cause of death of the fourteenth recipient of the AbioCor artificial heart, and what were the relative contributions to his demise of his overall medical condition, device function or malfunction, and/or device-related complications?

Dr. Kung: Because of patient confidentiality issues, I cannot give much detail. Mr. Wiley did not recover from multiple organ failure. His device worked well, and there were no malfunctions.

Medscape: Was this considered a positive or negative result in this patient, given his anticipated survival without the device and quality of life with the device?

Dr. Kung: Like all participants in the trial, Mr. Wiley had an expected survival of less than thirty days when he was enrolled. We were able to give him time with his family. Of course, our ultimate goal, particularly as we move beyond the initial clinical trial, is to be able to send patients home. One of our patients, Mr. Tom Christerson, survived 17 months and was able to return home.

Medscape: What criteria are used to determine eligibility for the AbioCor artificial heart?

Dr. Kung: Under the initial clincial trial, the AbioCor Implantable Replacement Heart System is indicated for patients who may benefit from heart replacement and who do not meet the criteria for receiving a left ventricular assist device (LVAD), or patients who are not likely to benefit from, or may encounter unacceptably high risks of complications or harm from, long-term assist with an LVAD or other device. Included in this group are persons with the following conditions: severe right ventricular failure in addition to severe left ventricular failure, pulmonary hypertension refractory to pharmacologic management, significant aortic valve regurgitation, mechanical valve prosthesis, intractable life-threatening arrhythmias, massive acute myocardial infarction with friable tissue, ventricular septal rupture, failed heart transplant (rejection) with immunosuppression, [or] thrombus in the ventricles.

Medscape: How would you summarize the overall experience with the AbioCor artificial heart to date?

Dr. Kung: A total of 14 patients have been previously enrolled. Twelve patients have been supported by the AbioCor for a combined period of approximately 5.3 patient-years, or an average duration of support of 5.4 months. As a comparison, median survival for patients accepted for the trial but not enrolled is around two weeks. One of the patients in the trial was discharged home and survived for 17 months. Many of the AbioCor patients were able to enjoy activities of daily living such as attending shows, sports events, visiting with friends and family, and dining out.

Medscape: What are the advantages and disadvantages of this device compared with other potential treatment options?

Dr. Kung: Only patients with no other treatment options qualify for the AbioCor. In addition, the system is entirely implantable, there are no drive lines or wires that pierce the skin. This allows for greater comfort, mobility, and quality of life for our patients.

Medscape: What additional testing is planned?

Dr. Kung: We have applied for limited commercial approval of the AbioCor under a humanitarian device exemption, which would make the AbioCor available to a defined population of up to 4,000 end-stage heart [failure] patients per year. We are also working on the AbioCor II, which is smaller and has a goal of achieving five-year reliability. We are doing additional animal implants with the AbioCor II in early 2005 and our hope is to be able to seek approval in 2008.

Medscape: How widespread do you anticipate use of the AbioCor artificial heart will become?

Dr. Kung: According to third party reports, up to 100,000 patients per year could benefit from total heart replacement. However, under a humanitarian device exemption, the use of the AbioCor I will not exceed 4,000 end-stage heart failure patients per year.

Medscape: Are there nonmedical issues that may limit use, such as cost, reimbursement, and need for specialized centers and/or surgical teams?

Dr. Kung: As part of our preparation, we are beginning to identify potential AbioCor centers beyond those that participated in the clinical trial. We anticipate over time there will be elite open-heart centers and transplant centers that will also be AbioCor Centers. We are also in the process of pursuing adequate reimbursement. There is a positive precedent in this area. This year, [the Centers for Medicare and Medicaid Services] designated DRG103 for reimbursement of implantable ventricular assist devices, a category which would likely include the AbioCor.

Reviewed by Gary D. Vogin, MD