Effect of ICD implantation on cardiovascular outcomes in patients with cardiac amyloidosis: A systematic review and meta-anaylsis

Introduction: Cardiac amyloidosis is associated with a high rate of sudden cardiac death (SCD). Whether implantable cardioverter-defibrillator (ICD) use in such patients prevents SCD is uncertain. This study assesses outcomes of ICD use in patients with cardiac amyloidosis. Methods: A systematic review and meta-analysis of data were performed after searching multiple databases and scientific sites pertaining to ICD use and cardiac amyloidosis. Of 8260 citations identified, six studies comprising 194 patients met inclusion criteria. Results: Mean values and frequencies of patient characteristics were as follows: mean NT-proBNP: 6867.9 pg/mL, mean left ventricular ejection fraction: 48.1%, heart failure: 67%, nonsustained ventricular tachycardia: 51%, syncope: 21%, and secondary prevention: 33%. During the mean follow-up period of 18.21 months, 18% of patients received appropriate ICD treatment and 5% received inappropriate ICD treatment. The mortality rate was 31%. Two studies assessed the difference between patients with appropriate ICD treatment and patients with absence of appropriate ICD treatment. There was no difference between the two groups when stratified on multiple selected third variables except for two subgroups. Male gender was associated with a higher rate of appropriate ICD treatment, whereas New York Heart Association class III or IV heart failure patients was associated with a lower rate of appropriate ICD treatment. Conclusion: The frequency of appropriate ICD treatment in cardiac amyloidosis is low and is not predicted by nonsustained ventricular tachycardia. Male gender is associated with appropriate ICD treatment. New York Heart Association class III or IV heart failure is associated with lower rate of appropriate ICD treatment.