Bansho Hiroki, Tomioka Daisuke, Geshi Toru, Sakai Hiroshi, Nakagawa Yoshihisa
Cardiology, Shiga University of Medical Science, Otsu, JPN.
Cardiology, Otsu Red Cross Hospital, Otsu, JPN.
Cureus. 2025 Jul 2;17(7):e87203. doi: 10.7759/cureus.87203. eCollection 2025 Jul.
Wild-type transthyretin amyloidosis (ATTRwt) is an age-associated systemic disorder characterized by extracellular deposition of misfolded transthyretin amyloid fibrils, leading to progressive organ dysfunction. Cardiac involvement is common and may result in restrictive cardiomyopathy, arrhythmias, and conduction disturbances, including left bundle branch block (LBBB). Although pharmacological therapy with transthyretin stabilizers, such as tafamidis, has been shown to reduce mortality in patients with ATTRwt cardiac amyloidosis (ATTRwt-CA), the role of device-based therapies, such as cardiac resynchronization therapy (CRT), remains controversial, particularly in patients with coexisting conduction abnormalities. We report the case of an 81-year-old woman diagnosed with ATTRwt-CA who presented with symptomatic heart failure and LBBB. Tafamidis therapy was initiated to improve her exercise tolerance and to reduce her risk of mortality. Owing to the presence of LBBB and evidence of mechanical dyssynchrony, CRT was also introduced in an effort to prevent the deterioration of her heart failure with reduced ejection fraction. Device optimization was guided by gated myocardial perfusion imaging, performed using single photon emission computed tomography (SPECT), which enabled a detailed assessment of her left ventricular synchrony and informed CRT programming. Following CRT implantation and optimization, the patient exhibited marked symptomatic improvement, including resolution of her exertional dyspnea and fatigue. Objective assessments demonstrated improved left ventricular contractility and reverse remodeling, suggesting a favorable response to CRT. This case underscores the potential value of CRT in selected patients with ATTRwt-CA and conduction system disease, particularly when mechanical dyssynchrony is evident. Furthermore, it highlights the utility of nuclear imaging modalities such as SPECT in guiding CRT optimization in this unique patient population. Prospective studies are warranted to better define the indications, predictors of response, and long-term outcomes of CRT in patients with ATTRwt-CA.
野生型转甲状腺素蛋白淀粉样变性（ATTRwt）是一种与年龄相关的全身性疾病，其特征是错误折叠的转甲状腺素蛋白淀粉样纤维在细胞外沉积，导致进行性器官功能障碍。心脏受累很常见，可能导致限制性心肌病、心律失常和传导障碍，包括左束支传导阻滞（LBBB）。尽管使用转甲状腺素蛋白稳定剂（如他氟米特）进行药物治疗已被证明可降低ATTRwt心脏淀粉样变性（ATTRwt-CA）患者的死亡率，但基于器械的治疗（如心脏再同步治疗（CRT））的作用仍存在争议，特别是在合并传导异常的患者中。我们报告了一例81岁女性患者，诊断为ATTRwt-CA，出现症状性心力衰竭和LBBB。开始使用他氟米特治疗以提高她的运动耐量并降低死亡风险。由于存在LBBB和机械不同步的证据，还引入了CRT，以防止她的射血分数降低的心力衰竭恶化。使用单光子发射计算机断层扫描（SPECT）进行的门控心肌灌注成像指导了器械优化，这使得能够详细评估她的左心室同步性并为CRT编程提供依据。在CRT植入和优化后，患者的症状有明显改善，包括劳力性呼吸困难和疲劳症状消失。客观评估显示左心室收缩力改善和逆向重构，提示对CRT有良好反应。该病例强调了CRT在选定的ATTRwt-CA和传导系统疾病患者中的潜在价值，特别是当机械不同步明显时。此外，它突出了核成像模式（如SPECT）在指导这一独特患者群体的CRT优化方面的实用性。有必要进行前瞻性研究，以更好地确定CRT在ATTRwt-CA患者中的适应症、反应预测因素和长期结果。
