Cardiac transplant dramatically improves survival and quality of life. One-year survival is 81%. For those that survive the first year, five-year survival is 85%.
However, morbidity rates are high. The crux of follow-up lies in careful management of immunosuppression, finding the balance between avoidance of rejection and avoidance of side effects of therapy.
The calcineurin inhibitors, tacrolimus and ciclosporin, form the mainstay of therapy and are most often used with corticosteroids and a cell-cycle agent, such as mycophenolate for long-term maintenance. Induction immunosuppression given pre-operatively is sometimes included. These drugs all target T cells, which drive the more preponderant cellular rejection. They have a multiplicity of side effects, many dose-dependent making monitoring of drug levels mandatory.
They have a multiplicity of side effects, many of which are dose-dependent making monitoring of drug levels mandatory.
Key factors to consider in long-term follow-up are:
- Anticipation and early treatment of allograft rejection: frequent studies of LV dimensions and wall thickness by echocardiography, accompanied usually by endomyocardial biopsy for histological assessment are required early after the transplant. If identified, treatment depends on the underlying mechanism.
– Cellular rejection (most common) responds to high dose corticosteroids
– Antibody-mediated rejection (e.g. due to pre-existing or de novo human leukocyte antigen (HLA) sensitisation) can warrant inhibition of B cells and antibody removal, for example by plasmapheresis.
- Monitoring for evidence of chronic allograft dysfunction; usually ‘cardiac allograft vasculopathy’ (CAV) which may present as angina. It is often diffuse and therefore not amenable to revascularisation. Careful symptomatic (anti-anginals) and preventative (statin) medical therapy is a priority; most patients are started on low dose atorvastatin (10 mg once daily) due to lower incidence of myositis compared with other statins.
- Stringent monitoring of drug levels and renal function is essential to prevent nephropathy. Kidney disease can be exacerbated by other factors such as pre- or peri-transplant renal injury, coexistent diabetes and hypertension.
- Careful management of hypertension and hyperlipidaemia, both common pre-morbid diagnoses that can be caused or exacerbated by immunosuppressive drugs. Cardiac denervation may also contribute to hypertension. Together, these can increase the risk of CAV.
- Prompt treatment of infection, due to patients’ ongoing susceptibility with immunosuppression, and the possibility of superadded bone marrow suppression due to the drugs.
- Monitoring for immunosuppression-associated malignancy, particularly non-melanoma skin tumours and B-lymphomas.
Despite these issues, cardiac transplantation remains the most effective definitive treatment for heart failure. The next steps will be in increasing donor organ supply to increase the numbers of patients receiving this life-saving therapy.