Atrial fibrillation in amyloidotic cardiomyopathy: prevalence, incidence, risk factors and prognostic role

Background: Although atrial fibrillation (AF) is a known complication of amyloidotic cardiomyopathy (AC), a precise pathophysiological and prognostic characterization is not available. We therefore aimed to assess prevalence, incidence, risk factors and prognostic significance of AF in light-chain (AL), hereditary transthyretin-related (m-ATTR) and non-mutant transthyretin-related (wt-ATTR) AC. Methods: Retrospective study of 262 patients with AC (123 AL, 94 m-ATTR, 45 wt-ATTR) from a single center. Results: AF prevalence was 15% (AL 9%, m-ATTR 11%, wt-ATTR 40%). During a median follow-up of 1.2 years 11 patients developed AF (2.1% person-years). Age, heart failure (HF), left ventricular (LV) ejection fraction, renal involvement, left atrial size and right atrial pressure were independently associated with AF. AF was associated with incident HF but not with increased mortality. All AF patients were prescribed warfarin and none suffered thromboembolic events. Conclusions: In AC the prevalence of AF varies widely according to etiology with a mean value of 15% that reaches 40% in wt-ATTR amyloidosis. Age, HF, LV ejection fraction, left atrial size and right atrial pressure were the main independent risk factors, while wall thickness and etiology were not the main independent risk factors. AF does not seem to impact all-cause mortality but was strongly associated with prevalent and incident HF.背景：心房颤动（atrial fibrillation, AF）是淀粉样变心肌病（amyloidotic cardiomyopathy, AC）的已知并发症，但目前尚无精准的病理生理及预后特征描述。本研究旨在评估轻链型（light-chain, AL）、遗传性转甲状腺素蛋白相关（hereditary transthyretin-related, m-ATTR）及野生型转甲状腺素蛋白相关（non-mutant transthyretin-related, wt-ATTR）淀粉样变心肌病患者心房颤动的患病率、发病率、危险因素及预后意义。 方法：本研究为单中心回顾性研究，纳入262例淀粉样变心肌病患者，其中AL型123例、m-ATTR型94例、wt-ATTR型45例。 结果：心房颤动总体患病率为15%，其中AL型为9%、m-ATTR型为11%、wt-ATTR型为40%。中位随访1.2年期间，共11例患者新发心房颤动，人年发病率为2.1%。年龄、心力衰竭（heart failure, HF）、左心室（left ventricular, LV）射血分数、肾脏受累、左心房内径及右心房压为心房颤动的独立危险因素。心房颤动与新发心力衰竭相关，但与死亡率升高无显著关联。所有心房颤动患者均接受华法林治疗，无一例发生血栓栓塞事件。 结论：淀粉样变心肌病患者的心房颤动患病率因病因不同差异显著，总体患病率为15%，在wt-ATTR型淀粉样变中可达40%。年龄、心力衰竭、左心室射血分数、左心房内径及右心房压为主要的独立危险因素，而室壁厚度及病因并非主要独立危险因素。心房颤动似乎对全因死亡率无显著影响，但与显性及新发心力衰竭密切相关。