The University of Maryland Medical Center's Mechanical Heart and Lung Support Program is also called the Mechanical Circulatory Support Device (MCSD) Program. The MCSD team is committed to providing state-of-the-art care specifically tailored to the individual needs of end-stage heart failure patients requiring mechanical circulatory support. Proven MCSDs are employed in bridge-to-heart-transplant, while new and established devices are offered as part of clinical research trials. In addition, UMMS is developing a lung support program to provide artificial lung suport for patients with end-stage or potentially reversible lung failure.
The University of Maryland Medical Center is committed to contributing to the scientific advances in patient selection, to the design and implantation of mechanical heart and lung support devices, and to optimal management of device recipients. Our long term goal is to build a brighter future for patients with heart and lung failure.
Most candidates for mechanical circulatory support are referred to the program by their primary physician or specialist. Others come to be evaluated at their own initiative. The process begins with a call to the ExpressCare Heart Center. The Cardiothoracic Transplant Office (410-328-2063) can also facilitate the referral process. The physician or patient will be asked to provide some basic medical information by telephone, and to provide us with written permission to obtain the patient's medical records from other health care providers.
Who Might Benefit from a MCSD?
The causes of congestive heart failure that result in the need for cardiac assist or replacement therapy are "ischemic" (not enough blood supply to the heart muscle) and primary (otherwise unexplained) cardiomyopathy. Together these two diagnoses account for about 9 of 10 heart device patients. Ischemic cardiomyopathy is caused by coronary artery disease.
Patients with coronary artery disease may suffer muscle damage from repeated or large heart attacks; if enough of the heart muscle is affected, the heart can no longer pump efficiently. Less often coronary artery narrowings which are associated with refractory chest discomfort or arrhythmias are found to be inoperable (not able to be treated by catheter techniques or open heart surgery). A small percentage of patients who undergo cardiac transplantation have valvular heart disease, congenital heart disease, or inoperable hypertrophic cardiomyopathy as the underlying condition.
All candidates for MCSD begin the program with a comprehensive series of tests conducted by our multidisciplinary team of specialists. Some of these tests are required for any operative procedure (history and physical, chest X-ray, EKG, etc.) while others are required to determine whether mechanical assist device surgery is likely to be safe or effective for an individual candidate. Still additional tests may be done for research purposes, if the patient agrees.
In general, patients with advanced heart failure who continue to have severe symptoms (breathlessness with little or no exercise, waking up at night short-winded) on maximal medical therapy should be considered for transplant or MCSD evaluation. Those patients who do not wish to consider transplantation, and patients for whom transplant is not a good option, are possible candidates for a MCSD. Conditions that might lead your heart failure physician to consider MCSD rather than transplant include:
Patients with increasing medication requirements, frequent hospitalizations, or overall deterioration of clinical status should be considered relatively urgently.
During the evaluation the patient and family will meet many members of the MCSD team, many of whom also participate in the transplant program. Each member of the team will want to get to know the candidate and their family, and/or other people who will provide significant emotional and practical support. There are so many of us because a successful device program requires people with different expertise.
While some aspects of device implant surgery have become routine, other aspects require innovation as we seek to make improvements in machines and in the way we manage patients who have one. This is where the experience of the team can make the difference between success and failure for an individual patient, particularly if the problem is unusual or serious.
If a MCSD is recommended and the patient agrees to proceed, the surgeons work together to direct and supervise the team of doctors, nurses, and allied health care providers who perform your device implant. Typically one surgeon will direct the surgical team, and then perform the actual transplant procedure and associated peri-operative care.
Once the evaluation is complete, the team will decide if medicines, conventional heart surgery, transplant, an alternative device or a MCSD, is the best option for each individual patient. The risks, benefits, and treatment options/alternatives will be discussed with each patient in detail. If the patient and the medical team agree that a MCSD is the best available choice, the patient is prepared for surgery at the University of Maryland.
MCSDs Currently Being Used at UMMC
Below are the MCSDs we are using as a Bridge to Transplant and as Destination Therapy (alternative to transplant). Click here for more information on these devices.
Devices currently used as Alternative to Transplant (Destination Therapy):
At the Maryland Heart Center we are part of a multi-center trial of the Novacor LVAS. Published data and our extensive experience suggest that this device is very reliable. For some patients who are not candidates for heart transplantation but are dying of heart failure, the INTREPID research trial offers qualifying patients access to this devices as "destination therapy" at the University of Maryland.
Using recent advances in component design and a sophisticated approach to managing blood thinners, we hope to offer our patients even breater benefits, with lower risks, in the future.
Bridge Patients: What to Expect While Waiting for Transplant
The time may be shorter or longer depending on the donor supply and the patient waiting list. Traditionally, patients stayed in the hospital until the new heart became available. Increasingly, as devices have become simpler and safer, patients who have a good response to the device are able to go home. While waiting, the patient is seen in clinic periodically to assist with any medical issues that may arise.
If a patient on a bridge device develops complications (infection, device malfunction, severe injury to blood cells "hemolysis"), this may increase the urgency of transplantation or require a major surgical procedure, possibly including replacement or removal of the device. In this case, if the team feels that the patient is likely to die without early transplant, the patient's heart transplant "status" can be increased to move them up on the list of waiting patients. Sometimes these complications or other complications (stroke, internal bleeding) can delay or prevent transplantation.
Patients who receive a device as "destination therapy" may subsequently improve enough to be considered for transplantation.
The Consent Process
Before receiving a MCSD, the patient and/or their family will engage in an often lengthy and complicated process of informed consent. The purpose of this process is to help the recipient and their caregivers to understand the normal procedures, known risks, and likely, possible, and unusual complications that may occur. The team will also do its best to help the patient understand what life with a mechanical assist device will be like for them. Because there is a lot to understand, the process takes time, and occurs in multiple steps. Particularly if an experimental device is being considered, or if an FDA-approved device is being used for a new or unapproved purpose ("indication"), then two or more separate consents may be required.
At any point in the consent process, a patient may elect not to participate. Once a device is implanted, a major additional operation is required to remove it. Alternatively, the device can be turned off. The consequences of having a device which is turned off vary depending on the device, but particularly for certain devices, the presence of the non-functioning device is very likely to worsen the patient's condition or result in serious or fatal complications.
Common complications after MCSD implantation include stroke, infection (minor or serious), device malfunction (unusual), and bleeding (common). Although we will do everything in our power to prevent complications, they remain very common. Indeed, almost every patient has at least one major complication associated with device implantation and subsequent long-term support.
Some devices are virtually silent. Other devices are noisy, though few patients find this bothersome and most patients (and their families) simply learn to ignore it. Taking care of the machine, and remembering its needs as well as the patient's, can be quite inconvenient. The consequences of not caring for the device can be life-threatening, so we make every effort to assure that only patients who understand this and have adequate supports in place actually receive a device.
We expect that every patient who receives a MCSD will improve, and will eventually be able to return to a more active, rewarding, enjoyable life outside the hospital. However, outcomes remain unpredictable, and at present we still have relatively little information about use of circulatory support devices for "destination therapy".
In recent trials of one machine, over half of patients who received a device were alive at the end of two years, and that at least on quarter will be alive at the end of the second year. These results were significantly better than similar patients who were treated with the best available medical therapy. Reference REMATCH trial, NEJM, November 11, 2001. We expect that results in the future can be improved based on lessons learned from this study, and from our own extensive prior experience.
Devices used at UMMC vary considerably in the specific steps required to attach them to your circulation. Prior surgery or other patient-specific factors can significantly affect the surgical approach and the ease of implantation for the patient and the surgeon.
The surgery lasts approximately three to eight hours. When the surgery is completed, the patient is taken to the intensive care unit. Over the subsequent days as you recover from surgery, the breathing tube and various drainage tubes and intravenous lines are gradually removed, and the process of rehabilitation is begun. Intravenous medicines that were needed before surgery are decreased slowly, as the right heart may still require some extra assistance during the first weeks to months after MCSD implant.
Occasionally, additional surgical procedures may be required to optimize pump
function or to address complications that may arise.
Careful, comprehensive post-surgical monitoring of blood thinning and organ function help to optimize recovery. The average length of stay in the intensive care unit is 3-7 days, followed by 1-2 weeks in the hospital.
The Patient's Responsibility
While mechanical circulatory support can greatly improve the quality of life of the recipients, it also demands much of them. They must become active participants in preserving their health. Care of the equipment (particularly battery maintenance), drive-line and IV sites, and general hygiene are important to prevent device malfunction or infection.
Typical Medicines Taken by MCSD Recipients:
Follow-up care initially involves returning to the Outpatient Clinic once a week for the first month after leaving the hospital. At this time a series of tests, including blood tests, are conducted to closely monitor the patient's progress. This is a period when medications are precisely adjusted. This process takes into account difference between different patients' medical and social circumstances in time and management steps needed to reach a point of stability. After this initial period, patients are seen periodically as determined by their condition. If a MCSD patient is on blood thinners, it is critical that these be carefully regulated until a stable level suitable for that patient is achieved.