Most studies of infiltrative cardiomyopathies and arrhythmias are small and observationalS7.6.1-1 but, in general, unless contraindications are present, VAs should be treated as in any other cardiomyopathy. See Section 7.6 for sarcoidosis. Until recently, cardiac amyloidosis was associated with a very poor prognosis with patients ultimately succumbing to progressive HF.S7.6.1-2 This perception is changing with advances in medical therapy for light-chain amyloidosis, which have led to improved outcomes.S7.6.1-3 Yet, decisions must be individualized because data remain too limited to al- low formal recommendations as published reports on ICD effectiveness in amyloidosis are small, observa- tional and with limited follow up.S7.6.1-4 Whether there is greater benefit to ICD placement in light chain amyloidosis versus transthyreitin-related amyloidosis remains uncertain, because most studies included mainly patients with amyloid light-chain amyloidosis for which the rate of VA may be greater and prog- CLINICAL STATEMENTS AND GUIDELINES nosis is generally worse. Whether ICDs are effective for primary prevention of SCD is uncertain, but many deaths in patients with cardiac amyloidosis do not ap- pear to be preventable by an ICD.S7.6.1-2 7.7. Heart Failure 7.7.1. HF With Reduced Ejection Fraction Recommendation for HFrEF References that support the recommendation are summarized in Online Data Supplement 35. COR LOE Recommendation IIa B-NR In patients with HFrEF who are awaiting heart transplant and who otherwise would not qualify for an ICD (eg, NYHA class IV and/ or use of inotropes) with a plan to discharge home, an ICD is reasonable.S7.7.1-1 S7.7.1-5 Synopsis Patients with HFrEF are at an increased risk for VA and SCD. The risk is increased irrespective of HFrEF SCD makes up a greater proportion of deaths in patients with milder HF symptoms and lesser proportion in those with moderate/severe HF The reported incidence of SCD varies depending on the definition used and the population studied. 