Data_Sheet_1_Prognosis of Paradoxical Low-Flow Low-Gradient Aortic Stenosis: A Severe, Non-critical Form, With Surgical Treatment Benefits.pdf

ObjectivesTo determine the risk of mortality and need for aortic valve replacement (AVR) in patients with low-flow low-gradient (LFLG) aortic stenosis (AS).
MethodsA longitudinal multicentre study including consecutive patients with severe AS (aortic valve area [AVA] < 1.0 cm2) and normal left ventricular ejection fraction (LVEF). Patients were classified as: high-gradient (HG, mean gradient ≥ 40 mmHg), normal-flow low-gradient (NFLG, mean gradient < 40 mmHg, indexed systolic volume (SVi) > 35 ml/m2) and LFLG (mean gradient < 40 mmHg, SVi ≤ 35 ml/m2).
ResultsOf 1,391 patients, 147 (10.5%) had LFLG, 752 (54.1%) HG, and 492 (35.4%) NFLG. Echocardiographic parameters of the LFLG group showed similar AVA to the HG group but with less severity in the dimensionless index, calcification, and hypertrophy. The HG group required AVR earlier than NFLG (p < 0.001) and LFLG (p < 0.001), with no differences between LFLG and NFLG groups (p = 0.358). Overall mortality was 27.7% (CI 95% 25.3–30.1) with no differences among groups (p = 0.319). The impact of AVR in terms of overall mortality reduction was observed the most in patients with HG (hazard ratio [HR]: 0.17; 95% CI: 0.12–0.23; p < 0.001), followed by patients with LFLG (HR: 0.25; 95% CI: 0.13–0.49; p < 0.001), and finally patients with NFLG (HR: 0.29; 95% CI: 0.20–0.44; p < 0.001), with a risk reduction of 84, 75, and 71%, respectively.
ConclusionsParadoxical LFLG AS affects 10.5% of severe AS, and has a lower need for AVR than the HG group and similar to the NFLG group, with no differences in mortality. AVR had a lower impact on LFLG AS compared with HG AS. Therefore, the findings of the present study showed LFLG AS to have an intermediate clinical risk profile between the HG and NFHG groups.

研究目标：明确低流量低梯度（low-flow low-gradient, LFLG）型主动脉瓣狭窄（aortic stenosis, AS）患者的死亡风险与主动脉瓣置换术（aortic valve replacement, AVR）的临床需求。研究方法：本研究为一项纵向多中心队列研究，纳入连续入选的重度AS患者（主动脉瓣面积[aortic valve area, AVA] <1.0 cm²）且左心室射血分数（left ventricular ejection fraction, LVEF）正常。根据临床指标将患者分为三组：高梯度组（high-gradient, HG，平均跨瓣压差≥40 mmHg）、正常流量低梯度组（normal-flow low-gradient, NFLG，平均跨瓣压差<40 mmHg，收缩期容量指数[indexed systolic volume, SVi] >35 ml/m²）以及LFLG组（平均跨瓣压差<40 mmHg，SVi ≤35 ml/m²）。研究结果：本研究共纳入1391例患者，其中147例（10.5%）为LFLG型AS，752例（54.1%）为HG型AS，492例（35.4%）为NFLG型AS。LFLG组患者的超声心动图参数显示，其AVA水平与HG组无显著差异，但无因次指标、瓣膜钙化及心室肥厚程度均轻于HG组。HG组患者接受AVR的时间早于NFLG组（p<0.001）与LFLG组（p<0.001），而LFLG组与NFLG组之间无统计学差异（p=0.358）。三组患者的总体死亡率为27.7%（95%置信区间[CI]：25.3%~30.1%），组间无显著差异（p=0.319）。AVR对总体死亡率的降低作用在HG组患者中最为显著（风险比（hazard ratio, HR）=0.17；95%CI：0.12~0.23；p<0.001），其次为LFLG组（HR=0.25；95%CI：0.13~0.49；p<0.001），最后为NFLG组（HR=0.29；95%CI：0.20~0.44；p<0.001），三组的死亡风险分别降低84%、75%与71%。研究结论：矛盾性LFLG型AS约占重度AS患者的10.5%，其AVR临床需求低于HG组，与NFLG组相当，且三组患者的死亡率无显著差异。相较于HG型AS，AVR对LFLG型AS的死亡风险改善作用较弱。综上，本研究结果显示，LFLG型AS的临床风险分层介于HG组与NFLG组之间。