Yuan Yifang, Herrington David, Lima Joao A C, Stacey R Brandon, Zhao David, Thomas James, Garcia Mario, Pu Min
Section on Cardiology, Wake Forest University Cardiology, Johns Hopkins University, Winston-Salem, NC.
Division of Cardiology, Johns Hopkins University, Baltimore, ML.
Mayo Clin Proc Innov Qual Outcomes. 2023 Sep 29;7(5):443-451. doi: 10.1016/j.mayocpiqo.2023.08.003. eCollection 2023 Oct.
To assess prevalence, clinical characteristics, and risk factors associated with low flow state (LFS) in a multiethnic population with normal left ventricular ejection fraction (LVEF).
The study included 4398 asymptomatic participants undergoing cardiac magnetic resonance from July 17, 2000, to August 29, 2002. Left ventricular (LV) mass, volume, and myocardial contraction fraction were assessed. Low flow state was defined as stroke volume index (SVi of <35 mL/m). Clinical characteristics, cardiac risk factors, and cardiac magnetic resonance findings were compared between LFS and normal flow state (NFS) groups (NFS: SVi of ≥35 mL/m).
There were significant differences in the prevalence of LFS in different ethnic groups. Individuals with LFS were older (66±9.6 vs 61±10 years; <.0001). The prevalence of LFS was 19% in the group aged older than 70 years. The logistic multivariable regression analysis found that age was independently associated with LFS. The LFS group had significantly higher prevalence of diabetes (30% vs 24%; =.001), LV mass-volume ratio (1.13±0.22 vs 0.91±0.15; <.0001), inflammatory markers, a lower LV mass index (59±10 vs 65±11 kg/m2; <.001), lower myocardial contraction fraction (58.1±10.6% vs 75.7±13%; <.001), and a lower left atrial size index (32.2±4.6 vs 36.7±5.9 mm/m2; <.0001) than NFS.
Low flow state may be considered an under-recognized clinical entity associated with increasing age, multiple risk factors, increased inflammatory markers, a lower LV mass index, and suboptimal myocardial performance despite the presence of normal LVEF and absence of valvular disease.
评估左心室射血分数（LVEF）正常的多民族人群中低流量状态（LFS）的患病率、临床特征及相关危险因素。
本研究纳入了2000年7月17日至2002年8月29日期间接受心脏磁共振检查的4398名无症状参与者。评估左心室（LV）质量、容积及心肌收缩分数。低流量状态定义为每平方米体表面积的每搏输出量指数（SVi）<35 mL/m。比较LFS组与正常流量状态（NFS）组（NFS：SVi≥35 mL/m）的临床特征、心脏危险因素及心脏磁共振检查结果。
不同种族人群中LFS的患病率存在显著差异。LFS患者年龄更大（66±9.6岁对61±10岁；P<.0001）。70岁以上人群中LFS的患病率为19%。多因素logistic回归分析发现年龄与LFS独立相关。LFS组糖尿病患病率显著更高（30%对24%；P=.001），左心室质量容积比更高（1.13±0.22对0.91±0.15；P<.0001），炎症标志物水平更高，左心室质量指数更低（59±10对65±11 kg/m2；P<.001），心肌收缩分数更低（58.1±10.6%对75.7±13%；P<.001），左心房大小指数更低（32.2±4.6对36.7±5.9 mm/m2；P<.0001）。
尽管LVEF正常且无瓣膜疾病，但低流量状态可能是一种未被充分认识的临床实体，与年龄增长、多种危险因素、炎症标志物增加、左心室质量指数降低及心肌功能欠佳有关。
