Increased Risk of Heart Block in Patients with Cardiac Amyloidosis on Amiodarone

Abstract

Background: Amiodarone is associated with heart block in patients with atrial fibrillation and heart failure. The safety of amiodarone use in patients with amyloid is unknown. We sought to identify the prevalence of heart block in patients with amyloid and heart failure who received amiodarone and compare them to those without amyloid in elderly patients. Methods: We searched Explorys (Explorys Inc, Cleveland, Ohio), a database that aggregates electronic health records of 45 million patients from 23 integrated health systems in the United States. We included patients who are at least 55 years of age who have heart failure and atrial fibrillation and receive amiodarone therapy. We compared those to age adjusted controls with heart failure and atrial fibrillation without amyloidosis. Results: We identified 640 patients with amyloid and 87280 patients without amyloid. Prevalence of block was higher in patients with amyloid on amiodarone (43.8% vs 30.0%, p!0.0001). When adjusted for age, odds ratio of block was as follows: 55-59 (1..0-1.8], p50.052), and 90+ (1.2 [0.9-1.7], p50.25), figure. Conclusion: Elderly patients with amyloidosis and heart failure who receive amiodarone are at higher risk of developing heart block. Amiodarone in this population should be used with caution and risk-benefit ratio should be addressed.Introduction: New onset heart failure (HF) in orthotopic liver transplant (OLT) patients has been described in the literature as a relatively uncommon but highly mortal condition. The pathophysiology remains unknown with many proposed theories. Current guidelines recommend against transplanting patients with heart failure. However, to date, there are no evidence-based screening algorithms to identify patients at risk for this clinical entity. Aims: We aimed to retrospectively explore the risk factors of both early and late HF in OLT and the utility of Dobutamine stress echocardiogram (DSE) in this regard. Methods: Medical records of 488 patient who received cadaveric OLT during the period of Jan.2001-Dec.2013 were reviewed. Echocardiographic and clinical parameters were examined as predictors of new HF using logistic regression analysis. HF was defined as either left ventricular (LV) ejection fraction of ! 45% or having diagnostic clinical features. 30 days post operatively was the cut off for early vs late HF. Echocardiographic assessment of diastolic function was not included in the analysis. Results: 262 patients had complete records including pre and post-OLT echocardiograms. 63% were males and 85% were Caucasians. History of ischemic heart disease was present in 5% and none had prior HF. Incidence of early HF was 6.9% (18 patients) and 9.9% (25 patients) for late HF. Median time to follow up echocardiogram was 251 days (interquartile range 46-1170 days). Pre-transplantation DSE was performed in 60% of analyzed cases and none of its parameters was associated with post-OLT HF. Independent predictors of developing HF were pre-OLT LV ejection fraction (MD -2.7%, P 0.001), LV systolic diameter (MD 1.6...

Comparison of posttransplant outcomes in patients with no, acute, or chronic amiodarone use before heart transplantation

“…The limited use of amiodarone in patients with cardiac amyloidosis might result from the little evidence for the safety and benefit of amiodarone against arrhythmias in this cohort. 22 , 23 Additionally, amiodarone therapy due to VT or VF is less frequent as those patients often do not survive the initial arrhythmic disorder and sudden cardiac death is found to be a result of electromechanical dissociation. 24 , 25 …”

Cardiac arrhythmias and amyloidosis

“…Los BB, aunque con frecuencia utilizados en el control de la TV, pueden ser perjudiciales por reducir el gasto cardíaco en pacientes con AC (30) . La amiodarona, que es un tratamiento efectivo contra la TV, puede tener complicaciones en el tratamiento de los pacientes con AC, particularmente prolongando el intervalo QTc y aumentando el riesgo de Torsades de Pointes, empeorando la función sistólica a través de actividad intrínseca betaantagonista y bloqueo cardíaco completo en comparación a pacientes sin AC, como fue demostrado en un estudio (43,8% vs. 30,0%, p<0,0001) (37) .…”

Narrative review of pharmacotherapy for transthyretin cardiac amyloid

“…Amiodarone increases the risk of heart block in cardiac ATTR, although patients must also be monitored for the known toxicities (42). Stablished guidelines should be followed to consider placement for permanent pacemaker.…”