Emma O'Donnell, Shazia Kaka, Helen Patterson and Carole Ann Boyle provide dental teams with knowledge on the background and process of cardiac transplant and explain the implications for oral health and dental management.

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Introduction

What is a cardiac transplant?

A cardiac transplant is a surgical procedure that replaces a severely diseased heart with a healthy heart from a recently deceased donor.1 It is most commonly indicated for people with advanced heart failure or those with recurrent, symptomatic, life-threatening arrythmias, which are unresponsive to maximal medical and/or surgical treatment.2 Coronary artery disease, congenital heart disease, valvular heart disease, or myocardial disease can all produce these end stage complications where the diseased heart fails to support a physiological circulation. Poor quality of life ensues with symptoms including breathlessness, fatigue, dizziness, chest pain, cough and risk of sudden death (1% per year).3

Cardiac transplant is the recommended treatment option to help restore cardiac function and prolong life.1 In 2021/22, 179 heart transplants were performed across seven centres in the UK (Table 1),4 with five-year survival rates of 71%.1

Table 1 Location for cardiac transplants within the UK
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When donors are not immediately available, ventricular assist devices (VADs) can be used as a short-term measure to help support life. These are battery operated, mechanical pumps surgically implanted into the heart's left ventricle, to either partially or completely replace the function of a heart. While results are variable, a recent systematic review reported 12-, 24- and 48-month survival rates of 82%, 72% and 57%, respectively.5

Those at high risk of developing dangerous arrythmias may have an implantable cardioverter defibrillator (ICD) in place. These devices, on detecting an abnormal rhythm, deliver either small rapid pacing impulses or a larger electric shock to restore normal rhythm. If an ICD is in place, it is useful to ascertain the frequency of shocks and how recently these have occurred. This allows the clinician to risk assess the possibility of shocks in the dental surgery and ensure they are treated in the most appropriate environment.

Acceptance for cardiac transplantation

The multidisciplinary cardiac transplant team carries out a thorough medical assessment and decides, within 18 weeks, whether to list the patient for a heart transplant. If deemed suitable, the patient is assigned to either the super-urgent, urgent, or non-urgent heart transplant list.

The majority of non-urgent patients are out of hospital and stable. Those on urgent lists tend to be inpatients in hospital on intravenous (IV) medication, while those on the super-urgent list are commonly in intensive care units (ICUs), with IV monitoring equipment or left VADs to sustain heart function.

How is a cardiac transplant carried out?

Cardiac transplantation is complex, high-risk and takes 4-6 hours. During the surgery, the patient is placed on a heart-lung bypass machine to keep blood circulating with adequate oxygen. The patient's damaged heart is removed and the donor heart put in place. The patient is moved to an ICU for further medical support and optimisation of recovery before being stepped down over the course of 2-3 weeks. During recovery, high dose immunosuppressive regimes are used to reduce the risk of transplant rejection. This rejection risk is highest within the first 3-6 months post-transplant and subsequently reduces with time.6

The post-transplant period

Rejection of the transplanted heart is a major cause of morbidity and mortality.6 An important balance must therefore be struck throughout the patient's life between ensuring sufficient immunosuppression to avoid rejection while minimising the main sequelae of immunosuppression, namely infection and malignancies.

Induction regimes provide intense early post-operative immunosuppression, with drugs including monoclonal antibodies (eg basilixamab, daclizumab, alemtuzumab) and polyclonal antibodies (eg antilymphocyte and antithymocte globulin). These usually continue for 2-3 weeks, resulting in significant depletion of a patient's T- and B-cells. During this period, prophylactic antibacterials, antifungals and antivirals are commonly used to reduce infection risks. Maintenance regimes are subsequently commenced which continue through the patient's life. While regimes will vary, combination therapies consisting of a steroid, a calcineurin inhibitor (cyclosporin A, tacrolimus, sirolimus, everolimus) and an antimetabolite (eg mycophenolate mofetil or azathioprine) are most commonly used. Therapy is gradually decreased over time, with efforts now being made to discontinue steroid therapy 6-12 months after heart transplantation.6 The numerous medications patients may be taking and their significance is summarised in Table 2.

Table 2 Dental considerations of post-transplant medications
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Cardiac transplant protocol

Dental assessments make a significant contribution towards the workup for cardiac transplantation. There is, however, little guidance on which dental teams should do this, where it should be done, and the factors that require consideration when deciding which treatment should be carried out.

Tables 3, 4, 5, 6 and 7 present a proposed protocol to answer these questions through a patient's transplant journey.

Table 3 Cardiac transplant dental protocol for patients being considered for cardiac transplant
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Table 4 Cardiac transplant dental protocol for patients then placed on routine waiting list
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Table 5 Cardiac transplant dental protocol for those on cardiac transplant waiting list with ventricular assist device in situ
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Table 6 Cardiac transplant dental protocol for those on urgent and super urgent cardiac transplant waiting list
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Table 7 Cardiac transplant dental protocol for treatment post-transplant
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Cardiac transplant and the role of the general dental practitioner

Care of this unique patient group requires a shared approach between the general dental practitioner (GDP), specialist dental teams and cardiac transplant teams. Regardless of setting, all clinicians should prioritise prevention, disease stabilisation, removal of any potential or active infective sources, and ensure a thorough soft tissue assessment. Generally, the dental workup before waiting list acceptance will occur in a hospital setting; however, if medically fit for primary care, the GDP could optimise oral health for transplant using the principles found in Table 3. Regular oral health examinations in primary care should be implemented alongside specialist dental team review, in keeping with enhanced prevention and recall schedules. Close surveillance of this cohort will ensure early detection of dental disease development which may influence their suitability for transplant, with potential suspension from the transplant waiting list. Should the GDP find evidence of infection or dental disease, the cardiac and specialist dental team should be made aware urgently. Following transplant, the patient should not receive any invasive dental treatment outwith a hospital site until medically stable. Post-transplant, the patient, if stable, is generally appropriate for treatment in general practice after two years. Non-invasive dental treatment is suitable in general practice pre- and post-transplant, should the patient be medically well enough to attend primary care. Additionally, patients with VADs require regular recall and to be managed by the specialist dental team should they require treatment alongside prophylactic antibiotics for invasive procedures that could cause bacteraemia.

Cases

The case series below illustrates the practical application of the cardiac transplant dental protocol and the holistic approach to care considered for these patients throughout their journey.

Case 1

A 49-year-old attended the dental clinic with a cardiac nurse following a referral from the specialist cardiac centre. They were an inpatient at the time, having been admitted two weeks prior due to acute heart failure on a background of ischaemic cardiomyopathy. They had an implantable cardioverter defibrillator in situ with no shocks to date and were being considered for cardiac transplantation. The patient was anticoagulated with warfarin, with a target international normalised ratio (INR) of between 2-3. Additionally, they were on clopidogrel and heart failure medications. They had not attended a dentist in 20 years as they had experienced no discomfort from their dentition.

Clinical and radiographic examination revealed extremely poor oral hygiene with multiple retained roots. The patient wore an upper acrylic denture, beneath which was food packing and evidence of denture stomatitis.

The treatment plan included oral hygiene instructions (OHI) and denture hygiene advice, ten extractions, professional mechanical plaque removal (PMPR) on all remaining lower teeth and construction of a new denture. Treatment was carried out using a staged approach, limiting adrenaline containing local anaesthesia to two cartridges per session, and ensuring a pre-op INR check. While pre-operative antibiotic cover would not usually be advised, in this case, the patient's cardiac transplant team were concerned about the risk of ICD-related endocarditis and specifically requested that cover was given.

Case 2

A 42-year-old was admitted to hospital with heart failure and a new diagnosis of dilated cardiomyopathy. An intra-aortic balloon pump (IABP) was inserted and they were commenced on milrinone and furosemide, before being placed on the urgent cardiac transplant waiting list.

As per local protocol, the patient was referred to the special care dentistry (SCD) team for assessment. As they were attached to an IABP, they were seen on the ward and could not leave the ward for radiographs. They had last attended a dentist nine years ago. Bedside assessment revealed poor oral hygiene with extensive caries in the 36 and 38. They were judged to require a full assessment including radiographs and would then require OHI, scaling and extraction of at least these molars to optimise their oral health before transplant. Unfortunately, the patient's unstable medical status prevented completion of dental treatment as it was felt, following liaison with the cardiac team, that the risks outweighed the potential benefits. In this case, regular dental review was maintained to encourage oral hygiene measures and check for any deterioration in the dental condition.

The patient underwent a cardiac transplantation and were commenced on tacrolimus, mycophenolate mofetil and prednisolone as per the unit's immunosuppression protocol. Additionally, they started alendronic acid for steroid-related bone protection, pravastatin as prophylaxis for graft vasculopathy, furosemide for volume overload, co-trimoxazole for pneumocystis pneumonia prophylaxis, and nystatin.

They experienced a number of post-operative complications, including pressure sores, a chest infection and posterior reversible encephalopathy syndrome.

Several months after transplant, the patient was reviewed in the SCD clinic where they complained of a sore tongue. The pain had been present for two months and was limiting eating. Examination was difficult due to pain, but a large ulcer was seen on the postero-lateral aspect of the tongue which extended to the left tonsil. Adjacent to this were two grossly carious and fractured teeth. Differential diagnoses included trauma, drug side-effect, or malignancy. Due to its association with oral ulceration, tacrolimus was withdrawn by the medical team and the patient commenced on cyclosporin. Additionally, an incisional biopsy was planned. Histopathology confirmed the ulcer to be a post-transplant lymphoproliferative disorder with the features of a high-grade B-cell lymphoma. Computerised tomography and positron emission tomography scans showed involved nodes in the mediastinum, liver, supra-clavicular regions, tonsil, pelvis, abdomen and colon.

The patient was urgently referred to haematology and started on R-CHOP chemotherapy. They developed neutropenic sepsis during their first and second rounds of chemotherapy and were then treated with a third round as an inpatient as a precaution.

Case 3

A 42-year-old man was referred for pre-cardiac transplant dental assessment to SCD.

His medical history included hypertrophic cardiomyopathy, an ICD in situ and worsening heart failure symptoms. Medications included entresto, ezetimibe, bisoprolol, atorvastatin, lansoprazole, dapagliflozin, apixaban and clopidogrel. He was a regular dental attender and had been advised by his GDP that he required a tooth removed following the failure of a crown. Due to concerns regarding his medical history, his dentist was reluctant to proceed with the treatment. On examination, all extra- and intra-oral soft tissues were healthy.

Clinical and radiographic examination with an orthopantomograph (Fig. 1) revealed the upper left first permanent molar (26) to be temporarily dressed, with associated secondary caries. The lower right first permanent molar (46) had been previously root treated with residual apical pathology and minimal supragingival tooth structure, following previous preparation for an indirect restoration. The 48 displayed an occlusal carious lesion. Tooth surface loss, due to a likely combination of erosion and attrition, affected the palatal and incisal aspects of the upper anteriors, with evidence of fractured composite restorations. Localised calculus deposits were present around the lower anteriors with a basic periodontal examination score of 111/221.

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Dental panoramic tomograph of Case 3

The treatment plan included oral hygiene and diet advice, a prescription of high fluoride toothpaste and mouthwash, and education about the aetiology of tooth wear. Treatment completed included PMPR, extraction of the 46, restoration of the 26 and 48, repair of fractured anterior composites, and provision of a splint.

Conclusion

With increasing numbers of cardiac transplants being carried out, more of these patients will be encountered in a primary care setting. The principles of the cardiac transplant dental protocol should be followed. Post-transplant, any routine dental intervention should be avoided for at least six months, with subsequent care ideally shared by the GDP and an SCD team.

This article was originally published in the BDJ on 12 January 2024 in Volume 236 issue 1, pages 30 to 34.