Dahl Jordi S, Eleid Mackram F, Pislaru Sorin V, Scott Christopher G, Connolly Heidi M, Pellikka Patricia A
Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota, USA.
Division of Biostatistics Mayo Clinic, Rochester, Minnesota, USA.
Heart. 2015 Jul;101(13):1015-23. doi: 10.1136/heartjnl-2014-306838. Epub 2015 Mar 20.
Among patients with severe aortic stenosis (sAS) and preserved LVEF, those with low-flow, low-gradient sAS (LFLG-sAS) have an adverse prognosis. It has been proposed that LFLG-sAS represents an end-stage point of sAS, but longitudinal information has not been described. The aim was to determine whether LFLG-sAS represents an end-stage consequence of normal-flow, high-gradient sAS (NFHG-sAS) or a different entity.
From our transthoracic echocardiogram (TTE) database, we identified patients with sAS (aortic valve area <1 cm(2)) and preserved LVEF (≥50%), and from these, patients with LFLG-sAS (stroke volume index <35 mL/m(2) and mean transvalvular gradient <40 mm Hg) who had ≥1 additional TTE within five years prior to the index TTE. Patients were age/sex/date matched 2:1 with patients with NFHG-sAS and normal-flow, low-gradient (NFLG)-sAS who also had ≥1 TTE. Included were 1203 TTEs (383 index studies and 820 preceding studies).
In 78 patients with LFLG-sAS, an HG stage preceded the index TTE in only 4 (5%). During the five years preceding the index TTE, patients with LFLG-sAS developed increasing relative wall thickness (0.42 to 0.49; p<0.001) without change in LV mass index. Patients with NFHG-sAS had a marked increase in LV mass index (87 to 115 g/m(2); p<0.001). Patients with LFLG-sAS demonstrated the greatest reduction in LV end-diastolic diameters (-3 vs -1 for NFLG-sAS vs +2 mm for NFHG-sAS; p=0.001), deceleration time (-55 vs -3 vs +3 ms, respectively; p<0.01) and LVEF (-4 vs 0 vs 0%, respectively; p=0.01).
LFLG-sAS is a distinct presentation of sAS preceded by a unique remodelling pathway and is uncommonly preceded by an HG stage.
在重度主动脉瓣狭窄（sAS）且左心室射血分数（LVEF）保留的患者中，低流量、低梯度sAS（LFLG-sAS）患者预后不良。有人提出LFLG-sAS代表sAS的终末期，但尚未有纵向研究报道。本研究旨在确定LFLG-sAS是正常流量、高梯度sAS（NFHG-sAS）的终末期表现还是一种不同的疾病实体。
从我们的经胸超声心动图（TTE）数据库中，我们识别出患有sAS（主动脉瓣面积<1 cm²）且LVEF保留（≥50%）的患者，并从这些患者中筛选出在索引TTE前五年内有≥1次额外TTE检查的LFLG-sAS患者（每搏量指数<35 mL/m²且平均跨瓣压差<40 mmHg）。将患者按年龄/性别/日期以2:1的比例与NFHG-sAS以及正常流量、低梯度（NFLG）-sAS且同样有≥1次TTE检查的患者进行匹配。共纳入1203次TTE检查（383次索引研究和820次之前的研究）。
在78例LFLG-sAS患者中，仅有4例（5%）在索引TTE前处于高梯度（HG）阶段。在索引TTE前的五年中，LFLG-sAS患者的相对室壁厚度增加（从0.42增加至0.49；p<0.001），而左心室质量指数无变化。NFHG-sAS患者的左心室质量指数显著增加（从87增加至115 g/m²；p<0.001）。LFLG-sAS患者的左心室舒张末期内径减小最为明显（NFLG-sAS减小3 mm，NFHG-sAS增加2 mm；p=0.001），减速时间缩短（分别为-55、-3和+3 ms；p<0.01），LVEF降低（分别为-4%、0%和0%；p=0.01）。
LFLG-sAS是sAS的一种独特表现形式，其之前有独特的重塑途径，且很少有HG阶段作为前驱。
