Cardiac Biopsies – the only reliable procedure to monitor heart transplant recipients
Overview
Heart transplant recipients are monitored carefully for any signs of rejection. Doctors often perform cardiac ‘biopsy’, a procedure to take specimens of small pieces of the transplanted heart to examine under a microscope. This procedure involves advancing a catheter, a thin tube, through a vein to the heart. The catheter has a bioptome (a tiny instrument used to cut off a piece of tissue) at its end. The dose of medications and the type of immunosuppressive drugs may be changed by the doctor if the biopsy shows damaged cells.
What Is Heart Transplant Surgery?
A heart transplant surgery involves replacing a diseased heart with a donor’s healthy heart, especially in case of heart failure. Heart failure can be diagnosed by an Echocardiogram which measures the Ejection Fraction (EF) and by the rise of NT-pro BNP hormone in the blood as a response to the failing heart. In case of severe heart failure, the patient may need a heart transplant.
What is the Process for donating the heart for transplant?
For heart transplant, the heart needs to be donated from a person who is declared brain dead and is on a ventilator. Most transplant patients have to wait for a long time as there are more patients needing a transplant than there are deceased donors. Transplant patients are generally placed on the transplant waiting list. When a donor’s heart is available, the transplant patient is matched based on three factors:
- Pediatric status
- Medical urgency
- Distance from the donor hospital
Other crucial factors in the matching process for all organs include body size, blood type, and other pertinent medical information.
How are donor assessment and recipient preparation done?
The brain dead donor is evaluated by a series of echocardiographic, hemodynamic, hormonal, bronchoscopic and infectious disease parameters, to assess the quality and safety of transplanting the organ onto a recipient. Donor resuscitation is also carried out to improve the quality of the organ and transplant outcome, by a set of advanced therapeutic protocols administered to the brain dead donor. The recipient is also intensively assessed and kept in readiness for the impending transplant. Mechanical circulatory support devices like the ECMO and VAD are used for circulation in critically ill patients until the new organ becomes available.
How are the recipients monitored?
Cardiac Biopsy
Heart transplantrecipients are monitored for signs of rejection of the replaced heart by the body. Currently, the cardiac biopsy is the only reliable method of diagnosing rejection of the transplanted heart. The biopsy is performed regularly after surgery, whenever rejection is suspected, and to evaluate the adequacy of anti-rejection therapy.
In older children and adults, heart biopsies are performed on a routine basis, about every week for the first four weeks following the surgery and later with less frequency, depending on the patient’s course. After six months, many patients can get routine biopsies every three months. The need for biopsies (to check for signs of rejection) on a routine basis is indefinite.
If, while admitted in the hospital, a heart biopsy is performed, the patient should follow all instructions given by the attending physician. If a heart transplant patient is coming to the hospital for an outpatient biopsy, it is suggested that he/she:
- Should not take diuretics the evening before, or the morning of the biopsy
- Should have a ‘salty meals’ the night before
- Do not lift heavy objects for at least 24 hours after the biopsy
How does Cardiac Biopsy work?
Cardiac Biopsy is performed in the operating room or in a Cardiac Cath Lab. The procedure takes approximately 30 minutes. A doctor will give a local anesthetic to numb an area around the patient’s neck. A catheter (a long tube) called bioptome is inserted through a small incision on the right side of the patient’s neck then down into the heart. Sometimes, the biopsy catheter will be inserted through the vein of the patient’s groin if the veins in the neck are not accessible.
Fluoroscopy, a type of X-ray, helps the physicians guide the bioptome through the neck’s vein (jugular vein) and into the heart’s right ventricular chamber. The instrument’s jaws are opened and closed, snipping off and removing a small piece of tissue.
What happens after the biopsy?
After the biopsy, physicians will check the biopsy specimen (small piece of tissue removed) under the microscope for white blood cells, to understand if a patient is experiencing rejection. The results of the biopsy are generally available within 24 – 48 hours. A Transplant Coordinator will notify the patient on the outcomes as soon as possible.
The patient will be advised on the need for any changes in the medication regimen, based on the outcomes. An echocardiogram is performed with each heart biopsy to evaluate the ventricular function. The echocardiogram is used together with the heart biopsy to determine a treatment regimen.
What care has to be taken following biopsy?
After the biopsy, the patient’s neck area will be observed for bleeding. The patient will be asked to keep his/her head upright to avoid pressure in the jugular vein that may result in bleeding at the site of biopsy. Patients should immediately notify the physician or nurses if they experience either swelling or bleeding.
Unusual chest pain or shortness of breath immediately after biopsy may be a sign of complication and should be reported promptly. If the femoral approach (vein of the thigh – near the groin) is used, the patient will be asked to lie on his/her back with the leg straight for an hour following the procedure.
Conclusion
Biopsies of the heart muscle are generally performed every week for the first three to six weeks following a heart transplant surgery. Following this, biopsies are done every three months for the first year, and every year thereafter. It is very important for patients or their attenders to be aware of the infection and the potential signs of rejection so they can report them to the doctors and be treated promptly.
