Singleton Matthew J, Nelson M Benjamin, Samuel T Jake, Kitzman Dalane W, Brubaker Peter, Haykowsky Mark J, Upadhya Bharathi, Chen Haiying, Nelson Michael D
Department of Biostatistics and Data Science, Wake Forest School of Medicine, Winston-Salem, North Carolina.
Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, Texas.
J Card Fail. 2022 Apr;28(4):567-575. doi: 10.1016/j.cardfail.2021.10.010. Epub 2021 Nov 10.
Heart failure with preserved ejection fraction (HFpEF) is the fastest growing form of HF and is associated with high morbidity and mortality. The primary chronic symptom in HFpEF is exercise intolerance, associated with reduced quality of life. Emerging evidence implicates left atrial (LA) dysfunction as an important pathophysiologic mechanism. Here we extend prior observations by relating LA dysfunction to peak oxygen uptake (peak VO), physical function (distance walked in 6 minutes [6MWD]) and quality of life (Kansas City Cardiomyopathy Questionnaire).
We compared 75 older, obese, patients with HFpEF with 53 healthy age-matched controls. LA strain was assessed by magnetic resonance cine imaging using feature tracking. LA function was defined according to its 3 distinct phases, with the LA serving as a reservoir during systole, as a conduit during early diastole, and as a booster pump at the end of diastole. The LA stiffness index was calculated as the ratio of early mitral inflow velocity-to-early annular tissue velocity (E/e', by Doppler ultrasound examination) and LA reservoir strain. HFpEF had a decreased reservoir strain (16.4 ± 4.4% vs 18.2 ± 3.5%, P = .018), lower conduit strain (7.7 ± 3.3% vs 9.1 ± 3.4%, P = .028), and increased stiffness index (0.86 ± 0.39 vs 0.53 ± 0.18, P < .001), as well as decreased peak VO, 6MWD, and lower quality of life. Increased LA stiffness was independently associated with impaired peak VO (β = 9.0 ± 1.6, P < .001), 6MWD (β = 117 ± 22, P = .003), and Kansas City Cardiomyopathy Questionnaire score (β = -23 ± 5, P = .001), even after adjusting for clinical covariates.
LA stiffness is independently associated with impaired exercise tolerance and quality of life and may be an important therapeutic target in obese HFpEF.
NCT00959660.
射血分数保留的心力衰竭（HFpEF）是增长最快的心力衰竭形式，与高发病率和死亡率相关。HFpEF的主要慢性症状是运动耐量下降，这与生活质量降低有关。新出现的证据表明左心房（LA）功能障碍是一种重要的病理生理机制。在此，我们通过将LA功能障碍与峰值摄氧量（峰值VO₂）、身体功能（6分钟步行距离[6MWD]）和生活质量（堪萨斯城心肌病问卷）相关联，扩展了先前的观察结果。
我们将75例老年肥胖HFpEF患者与53例年龄匹配的健康对照者进行了比较。使用特征追踪的磁共振电影成像评估LA应变。LA功能根据其3个不同阶段来定义，在收缩期LA作为一个储存器，在舒张早期作为一个管道，在舒张末期作为一个增压泵。LA僵硬度指数计算为二尖瓣早期血流速度与早期二尖瓣环组织速度之比（通过多普勒超声检查的E/e'）和LA储存应变。HFpEF患者的储存应变降低（16.4±4.4%对18.2±3.5%，P = 0.018），管道应变降低（7.7±3.3%对9.1±3.4%，P = 0.028），僵硬度指数升高（0.86±0.39对0.53±0.18，P < 0.001），同时峰值VO₂、6MWD降低，生活质量下降。即使在调整临床协变量后，LA僵硬度增加也与峰值VO₂受损（β = 9.0±1.6，P < 0.001）、6MWD受损（β = 117±22，P = 0.003）和堪萨斯城心肌病问卷评分受损（β = -23±5，P = 0.001）独立相关。
LA僵硬度与运动耐量受损和生活质量独立相关，可能是肥胖HFpEF的一个重要治疗靶点。
NCT00959660。
