Background

The aim of the present study was to evaluate the clinical importance of echocardiographic coronary flow velocity reserve (CFVR), resting and exercise left ventricular global longitudinal strain (LVGLS), and myocardial work efficiency (MWE) in patients with cardiac amyloidosis (CA).

Methods

The study population comprised 69 subjects: group A, 27 patients with CA confirmed by endomyocardial biopsy (CA positive); group B, 42 healthy control subjects. The amyloid phenotype in group A was as follows: patients with wild-type transthyretin-related amyloidosis (n = 10), carriers of the Danish familial transthyretin amyloidosis mutation with cardiac involvement (n = 5), and patients with amyloid light chain amyloidosis with cardiac involvement (n = 12). All subjects underwent comprehensive echocardiographic evaluation during rest and during symptom-limited, semisupine exercise testing. Furthermore, CFVR was assessed using Doppler echocardiography.

Results

Patients with CA had significantly lower CFVR (1.7 ± 0.6 vs 3.9 ± 0.8, P < .0001), MWE (1.9 ± 1.0 vs 3.0 ± 0.7, P < .0001), and LVGLS magnitude (11% [10%–14%] vs 20% [18%–21%], P < .0001) than control subjects. Patients with CA showed severely reduced deformation and efficiency reserve compared with control subjects (ΔLVGLS 0.9 ± 2.8% vs 5.6 ± 2.3%, P < .0001; ΔMWE 2.5 ± 2.8 vs 8.8 ± 2.6, P < .0001). In patients with CA, a strong relation was seen between physical capacity by the metabolic equivalent of tasks test and CFVR (r = 0.55, P < .01), peak exercise LVGLS (r = 0.64, P < .0001), and peak exercise MWE (r = 0.60, P < .01).

Conclusions

Patients with CA had a profound lack of CFVR and longitudinal myocardial deformation reserve compared with healthy control subjects. Both parameters were significantly associated with exercise capacity and may prove useful for evaluating cardiac performance in patients with CA.

中文翻译：

---

冠状动脉血流速度储备异常和心肌收缩储备下降是与心脏淀粉样变性运动能力有关的主要因素

背景

本研究的目的是评估心脏淀粉样变性病（CA）患者的超声心动图冠状动脉血流速度储备（CFVR），休息和锻炼左心室总体纵向张力（LVGLS）和心肌工作效率（MWE）的临床重要性。

方法

研究人群包括69位受试者：A组，经心内膜活检证实的27例CA患者（CA阳性）；B组42例健康对照者。A组的淀粉样蛋白表型如下：患有野生型运甲状腺素蛋白相关淀粉样变性病的患者（n  = 10），具有心脏受累的丹麦家族性运甲状腺素蛋白淀粉样变性病的携带者（n  = 5）以及患有轻度淀粉样变性的轻链淀粉样变性病的患者心脏受累（n  = 12）。所有受试者在休息和症状受限的半仰卧运动测试中均接受了全面的超声心动图评估。此外，使用多普勒超声心动图评估CFVR。

结果

CA患者的CFVR（1.7±0.6 vs 3.9±0.8，P  <.0001），MWE（1.9±1.0 vs 3.0±0.7，P  <.0001）和LVGLS量级明显降低（11％[10％–14％ ] vs. 20％[18％–21％]，P  <.0001）。与对照组相比，CA患者的变形和效率储备显着降低（ΔLVGLS0.9±2.8％vs 5.6±2.3％，P  <.0001；ΔMWE2.5±2.8 vs 8.8±2.6，P  <.0001）。在CA患者中，通过任务测试的代谢当量与CFVR（r  = 0.55，P  <.01），峰值运动LVGLS（r  = 0.64，P）之间的身体承受能力之间存在密切关系。 <.0001）和最高运动量MWE（r  = 0.60，P  <.01）。

结论

与健康对照组相比，CA患者严重缺乏CFVR和纵向心肌变形储备。这两个参数均与运动能力显着相关，并且可能被证明可用于评估CA患者的心脏表现。