Cardiac
Therapy
Patients with subclinical cardiac function abnormalities should be referred to a cardiologist for assessment.
Non-pharmacological Management:
- Exercise Training
- Salt and fluid restriction
- Weight management
Pharmacological Management
Mechanisms of drugs used:
- ACE inhibition
- angiotensin blockade
- aldosterone antagonism
Enalapril (ACE inhibitor)
Reduces Left Ventricular afterload and tends to slow the progression of Left ventricular dysfunction9
In one study of long term effects of ACE inhibitor in childhood cancer survivors with anthracycline induced cardiac dysfunction11:
- Enalapril significantly improved LV dimension, afterload, fractional shortening and mass
- These gains were showed to be for the short term only as after 6-10 years on enalapril the benefits were lost
- This study also showed that LV wall thickness deteriorated along with LV contractility and systolic blood pressure throughout the duration of the study
- ACE inhibitors did not prevent the progression of LV dysfunction and thinning of the LV walls, though they did provide some help in the form of the afterload reduction.
ACE inhibitors may have short term benefits, but in children with adriamycin induced thinning of the ventricle, Enalapril may not be beneficial (may limit cardiac growth).
Absolute contraindications to ACE inhibitors:
- Hypersensitivity to this drug
- Angioedema related to previous treatment with an ACE inhibitor
- Patients with idiopathic or hereditary angioedema
- Pregnancy, especially in second and third trimesters
- Symptomatic hypotension
Relative contraindications:
- Renal insufficiency
- Hyperkalemia
- Breast feeding as ACE inhibitor is excreted in breast milk
- Interactions with other drugs (BP may fall if combined with a diuretic)
Beta-blockers
LV function can improve with beta-blockers11
Mechanism may be to reduce oxidative stress and rate of apoptosis.
Prophylactic use of the beta blocker Carvedilol in patients receiving anthracyclines may protect both systolic and diastolic functions of the left ventricle.
Absolute contraindications7
- Hypersensitivity to this drug class
- Sinus bradycardia
- Second and third degree AV heart block
- Cardiogenic shock
Relative contraindications
- Fatigue, dizziness, fainting, asthma
- Overt cardiac failure
Interactions with other drugs (combination with catecholamine-depleting drugs such as reserpine) may cause profound hypotension or marked bradycardia.
Growth Hormone
Growth hormone (GH) may act indirectly on the heart through the action of insulin-like growth factor (IGF-1) to maintain adequate left ventricular(LV) mass12.
- Insufficient GH levels are associated with thin LV walls and decreased LV contractility are believed to lead to increased LV afterload and LV dysfunction.
- GH deficiency also increases cardiac related mortality and dyslipidemia
- Some small pilot studies in adults with impaired LV structure and function found improved cardiac function, exercise performance and increased cardiac mass after GH therapy, but several randomized trails have found no clinical benefits of treatment despite the resulting increase in LV mass.
GH therapy may be of only short term benefit, as once the GH therapy was discontinued, any gains in LV wall thickness was lost.
GH treatment does not appear to affect progressive LV dysfunction12
Heart Transplantation
Adriamycin can cause severe restrictive cardiomyopathy7
Heart transplantation is often necessary for patients with end-stage cardiac failure14.
The goal of heart transplantation is to improve functional capacity, quality of life and length of life13.
All reversible factors should be treated before transplantation is contemplated7
Cancer survivors don’t require any special immunosuppression modification and the 2 year survival is similar to other recipients14
Prognosis is better after transplant than medically treated severe cardiomyopathy7.
Absolute contraindications14
- Active rheumatologic diseases
- Any major systemic condition with the potential of further deteriorating on immunosuppression
- Recurrent or new malignancy
Relative contraindications7
- Active infection
- Active ulcer disease
- Severe Diabetes mellitus
- Recently treated cancer (not yet reaching 5 year event-free survival)
- Any condition that limits the potential for full rehab, such as cognitive impairment, psychiatric instability, alcohol, drug abuse and repeated non compliance.
2001 Canadian Cardiovascular Society Consensus Conference on Cardiac Transplantation
