Cardiac manifestations may include atrial fibril- lation, conduction disturbances, VA, and NICM. A number of observational studies reported a high risk of SCD when cardiac involvement is One study reported SCD as the most frequent mode of death (46%) in both the isolated cardiac and the neuromuscular phe- notypes of Lamin diseases.S7.2.2-9 In a cohort of 269 LMNA mutation positive individuals,S7.2.2-10 NSVT during ambulatory electrocardiographic monitor- ing, LVEF <45% at first evaluation, male sex, and nonmissense mutations were independent risk factors for VA. Malignant VA were observed only in persons with 2 of these risk factors.S7.2.2-10 No studies have tested the effect of the ICD on long- term survival. 3. Patients with NICM and class I HF symptoms were not included in SCD-HeFT or DANISH.S7.2.2-1,S7.2.2-11 Although such patients were included in the DEFINITE trial, only 99 (21.6%) of 458 patients in the DEFINITE trial had class I HF.S7.2.2-5 Therefore, it is uncertain whether a primary prevention ICD in such patients improves survival. 4. There are insufficient data from RCTs regarding the value of the ICD in patients with NYHA class IV. Ambulatory class IV HF patients were included in the COMPANION trial that, overall, showed improved functional status and survival with a Unless such a patient is a candidate for CRT or advanced HF therapies such as heart transplantation or an LVAD, an ICD is not expected to meaningfully prolong survival.S7.2.2-3 7.2.3. Treatment of Recurrent VA in Patients With NICM Recommendations for Treatment of Recurrent VA in Patients With NICM References that support the recommendations are summarized in Online Data Supplement 29. 