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J Thorac Cardiovasc Surg 1999;117:1029-1030
© 1999 Mosby, Inc.
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From the Department of Cardiovascular Surgery,a Department of Cardiology,b Charité, Humboldt University Berlin, Schumannstraße 20/21 D-10117 Berlin, Germany
Received for publication Sept 24, 1998 Accepted for publication Oct 7, 1998 Address for reprints: P. M. Dohmen, MD, Department of Cardiovascular Surgery, Charité, Humboldt University Berlin, Schumannstraße 20/21, D-10117 Berlin, Germany.
The supply of donor hearts is inadequate to meet the needs of patients with end-stage heart disease, so alternatives to heart transplantation have been investigated. Surgical alternatives are partial left ventriculectomy,
1 cardiomyoplasty, 2 use of a total artificial heart, and implantation of a left ventricular assist device (LVAD). For mechanical support, the Jarvik heart (Symbion, Inc, Salt Lake City, Utah) was initially planned as a permanent application in patients who are unsuitable candidates for heart transplantation. 3
Because of the possible complications and the still imperfect system, one has to be very careful to identify patients for permanent implantation of an LVAD. 4 We report the case of a patient who has been living at home for more than 3 years with the Novacor portable LVAD (Baxter Healthcare Corp, Novacor Div, Oakland, Calif).
Clinical summary
A 54-year-old man was admitted to our hospital in April 1995 with severe congestive heart failure. The diagnosis of dilated cardiomyopathy was made in 1989 at a local hospital. The patient's other medical problems included tuberculosis in 1970 and pneumonia in 1995. Previous surgical interventions included an appendectomy in 1950 and a Billroth II operation in 1975 for a gastric ulcer; another cardiac risk factor was smoking. His medications on admission were enalapril, piretanide, spironolactone 50 mg, digitoxin, diazepam, magnesium, and phenprocoumon with an international normalized ratio (INR) between 3.0 and 3.5. Clinical examination showed no sign of cyanosis or peripheral edema, a blood pressure of 90/60 mm Hg, and a heart rate of 76 beats/min. By cardiac auscultation there was a holosystolic murmur (grade 2/6) at the fifth intercostal space. A 1-degree atrioventricular block was seen on the electrocardiogram. Transthoracic echocardiography and cardiac catherterization showed grade 3 tricuspid regurgitation, grade 2 mitral regurgitation, grade 1 aortic regurgitation, pulmonary hypertension (50 mm Hg), and global left ventricular hypokinesia with a left ventricular ejection fraction of 8%.
On admission to the intensive care unit in April 1995, the patient was having a period of acute cardiac decompensation that could not be compensated with nitroglycerin, nitroprusside, diuretics, and catecholamines.
On May 26, 1995, a Novacor N100 LVAD was implanted in the beating heart by the preperitoneal insertion technique. The postoperative period was complicated by transient renal failure, treated with continuous venovenous hemofiltration. Additionally the patient's recovery was complicated by bronchopneumonia, which was managed with high doses of antibiotics and antimycotics. A tracheostomy became necessary because of prolonged ventilation. Eventually the patient recovered progressively and was discharged to his home in September 1995 in New York Heart Association (NYHA) functional class I. The patient received training to monitor his INR at home. The medications at discharge were enalapril, acetylsalicylic acid, and phenprocoumon to maintain the INR between 3.0 and 3.5. Since then the patient has been checked twice a week by phone and by a short hospital stay every 6 months. During follow-up the recovery of left ventricular function, aortic valve function, exclusion of infections, and exclusion of intracardiac thrombus are evaluated. Hemodynamic re-evaluation with cardiac catheterization was done after 11, 19, and 28 months of implantation (Fig. 1). The device was routinely monitored by the Baxter Novacor Division for mechanical dysfunction (Table I). After more than 3 years of support with the Novacor N100 LVAD at full-rate trigger mode, the patient is doing well. Clinically he is in NYHA class I, driving a car, and traveling abroad for vacation.
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The surgical standard for end-stage cardiac failure is heart transplantation if medical therapy fails. The 5-year survival of patients undergoing cardiac transplantation is about 60% to 70% and the mortality of patients waiting for heart transplantation is between 20% and 30%, explained by the shortage of available heart donors. A logical consequence is the investigation of surgical treatments to offer patients alternatives while awaiting heart transplantation, as well as for patients excluded from transplantation. One of those alternatives is the wearable electrical LVAD. Because of the progressive failure of medical treatment, the Novacor LVAD was implanted in this patient. Westaby 5 reported recovery of myocardial function during the first months after unloading the left ventricle.
Inasmuch as our patient did not fulfill the weaning criteria, he has to be supported permanently with close monitoring of the device by energy converter, valve bioprostheses (and conduits), and acoustic characteristics, which in our patient are still in excellent condition after more than 3 years. The most readily retrievable data for monitoring the energy converter bearings are the sensor tuning and fail-safe current changes. The solenoid armatures tend to shift position as the main bearings wear and develop slack. Because the solenoid sensor flags are close to the main bearings, these shifts strongly affect solenoid sensor tuning. Fill and eject rates are the primary data for assessing valve and conduit function. The solenoid inherently does not emit specific "chatter" frequencies typical of rotary devices with worn bearings. However, changes in sound level and acoustic spectral characteristics may be useful for assessing degradation of pads, bearings, and other parts.
During the past period of more than 1000 days of support, we have observed no evidence of serious infection or thromboembolic complications.
Identifying the target population for permanent implantation of these devices includes patients who are excluded from heart transplantation, alternative surgical options, or weaning from the LVAD to increase their quality of life. More investigation is needed to improve the assist devices, making them more compact and totally implantable.
References
This article has been cited by other articles:
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  W. L. Holman, J. E. Davies, B. K. Rayburn, D. C. McGiffin, B. A. Foley, R. L. Benza, R. C. Bourge, P. Blood, and J. K. Kirklin Treatment of end-stage heart disease with outpatient ventricular assist devices Ann. Thorac. Surg., May 1, 2002; 73(5): 1489 - 1494. [Abstract] [Full Text] [PDF]
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 M. Zytowski, M. Zytowski, G. Baumann, H. Hotz, S. Dushe, C. Enzweiler, A. Borges, V. Borak, K. Redmann, P. P. Lunkenheimer, et al. Results of Batista Procedure in Ischemic Dilated Cardiomyopathy Asian Cardiovasc Thorac Ann, December 1, 2000; 8(4): 305 - 310. [Abstract] [Full Text] [PDF]
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K. C. de Jonge, H. R. Laube, P. M. Dohmen, V. Ivancevic, and W. F. Konertz Diagnosis and management of left ventricular assist device valve-endocarditis: LVAD valve replacement Ann. Thorac. Surg., October 1, 2000; 70(4): 1404 - 1405. [Abstract] [Full Text] [PDF]
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