Outcomes in patients with cardiac amyloidosis and implantable cardioverter-defibrillator

Abstract

Aims Cardiac amyloidosis (CA) is associated with increased mortality due to arrhythmias, heart failure, and electromechanical dissociation. However, the role of an implantable cardioverter-defibrillator (ICD) remains unclear. We conducted case-control study to assess survival in CA patients with and without a primary prevention ICD and compared outcomes to an age, sex, and device implant year-matched non-CA group with primary prevention ICD. Methods and results There were 91 subjects with CA [mean age= 71.2 ± 10.2, female 22.0%, 49 AL with Mayo Stage 2.9 ± 1.0, 41 transthyretin amyloidosis (ATTR), 1 other] followed by Vanderbilt Amyloidosis centre. Patients with ICD (n = 23) were compared with those without (n = 68) and a non-amyloid group with ICD (n = 46). All subjects with ICD had implantation for primary prevention. Mean left ventricular ejection fraction was 36.2% ± 14.4% in CA with ICD, 41.0% ± 10.6% in CA without ICD, and 33.5% ± 14.4% in non-CA patients. Over 3.5 ± 3.1 years, 6 (26.1%) CA, and 12 (26.1%) non-CA subjects received ICD therapies (P = 0.71). Patients with CA had a significantly higher mortality (43.9% vs. 17.4%, P = 0.002) compared with the non-CA group. Mean time from device implantation to death was 21.8 months in AL and 22.8 months in ATTR patients. There was no significant difference in mortality between CA patients who did and did not receive an ICD (39.0% vs. 46.0%, P = 0.59). Conclusions Despite comparable event rates patients with CA had a significantly higher mortality and ICDs were not associated with longer survival. With the emergence of effective therapy for AL amyloidosis, further study of ICD is needed in this group.

Electrophysiological Manifestations of Cardiac Amyloidosis

“…Furthermore, 2 of the studies compared survival in CA patients with an inserted ICD vs a control population following ICD insertion. Compared with the control population, patients with CA have significantly reduced survival ( 49 , 50 ). Interestingly, the largest study found 1-year mortality for patients with CA and an ICD to be 26.9% vs 11.3% for nonischemic cardiomyopathy control patients ( 49 ).…”

ATTR Amyloidosis: Current and Emerging Management Strategies

“…Sudden cardiac death in ATTR-CA is thought to be uncommon, especially compared with AL-CA, but prospective studies are lacking. Although a number of studies (including both AL- and ATTR-CA) have shown appropriate implantable cardioverter-defibrillator (ICD) use in CA patients, none have shown greater survival compared with CA patients without ICDs ( 26 , 41 , 42 , 43 , 44 , 45 ). The incidence of appropriate ICD use varied from 6% to 32%, although the duration of follow-up and composition of the cohort in each study was heterogeneous ( 26 ).…”

“…The 2017 American Heart Association/American College of Cardiology/Heart Rhythm Society guidelines recommend individualized decision making for both primary and secondary prevention with ICDs in CA ( 47 ). Despite incremental data on ICDs in CA since publication of these guidelines ( 41 , 45 ), the benefit of ICDs in ATTR-CA remains unclear.…”

Arrhythmic Sudden Cardiac Death and the Role of Implantable Cardioverter-Defibrillator in Patients with Cardiac Amyloidosis—A Narrative Literature Review

“…Kristen et al indicated low efficacy of ICD therapy and emphasized the frequent occurrence of electromechanical dissociation in CA patients [ 27 ]. On the contrary, several of the analyzed studies reported frequent and successful ICD therapy, but none of these have demonstrated a survival benefit [ 14 , 28 , 29 , 30 , 31 , 32 , 33 ].These discrepancies are due to multiple limitations of these studies. First, all of the studies included in this review were retrospective with various sample sizes (3–472 patients).…”