Divisions of Cardiovascular Diseases, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
Divisions of Biostatistics, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
Heart. 2015 Jan;101(1):23-9. doi: 10.1136/heartjnl-2014-306151. Epub 2014 Sep 12.
Low-gradient (LG) severe aortic stenosis (AS) and preserved EF with reduced stroke volume are associated with an adverse prognosis, but the relationship of stroke volume index (SVI) with mortality among a range of values is unknown. We investigated the prognostic impact of SVI in this population.
We examined 405 consecutive patients with preserved EF (≥50%) and severe AS (valve area <1.0 cm(2)) with LG (<40 mm Hg) using echocardiography. Patients were stratified into quartiles based on SVI distribution (group 1: <38 mL/m(2) (n=90), group 2: 38-43 mL/m(2) (n=105), group 3: 43-48 mL/m(2) (n=104) and group 4: >48 mL/m(2) (n=106)).
Groups 1 and 2 had poorer survival with medical management compared with 3 and 4 (3-year estimate 46% and 67% vs. 78% and 73%, respectively, p=0.002) although aortic valve replacement referral rate was similar (53%-62%, p=0.57). An inverse relationship was observed between SVI and mortality (HR 1.28 (1.11 to 1.46) per every 5 mL/m(2) decrease in SVI). After multivariable analysis, SVI was the strongest predictor of mortality (HR 0.92 (0.89 to 0.95), p<0.0001). Using different SVI cutpoints, SVI <35 was associated with highest mortality (HR 2.36 (1.49 to 3.73), p<0.001), followed by SVI <38 (HR 2.09 (1.39 to 3.16), p<0.001) and by SVI <43 (HR 2.05 (1.38 to 3.05), p<0.001). Survival with SVI ≥43 was similar to age and sex-matched controls (3-year estimate 84%, p=0.24); survival for SVI <43 was significantly worse (3-year estimate 63%, p<0.001).
Lower SVI is incrementally associated with mortality in LG severe AS with preserved EF. These findings have implications for classification of AS severity, identification of high-risk groups and subsequent management.
低梯度（LG）严重主动脉瓣狭窄（AS）和射血分数保留但心排量降低与不良预后相关，但在一系列值中，心排量指数（SVI）与死亡率的关系尚不清楚。我们研究了该人群中 SVI 的预后影响。
我们对 405 例射血分数保留（≥50%）和严重 AS（瓣口面积<1.0cm²）且 LG（<40mmHg）的连续患者进行了超声心动图检查。根据 SVI 分布将患者分为四组（组 1：<38mL/m²（n=90），组 2：38-43mL/m²（n=105），组 3：43-48mL/m²（n=104）和组 4：>48mL/m²（n=106））。
与组 3 和组 4 相比，组 1 和组 2 接受药物治疗的患者生存率较差（3 年估计值分别为 46%和 67%比 78%和 73%，p=0.002），尽管主动脉瓣置换转诊率相似（53%-62%，p=0.57）。SVI 与死亡率呈负相关（每降低 5mL/m² SVI，HR 为 1.28（1.11 至 1.46））。多变量分析后，SVI 是死亡率的最强预测因子（HR 0.92（0.89 至 0.95），p<0.0001）。使用不同的 SVI 切点，SVI<35 与最高死亡率相关（HR 2.36（1.49 至 3.73），p<0.001），其次是 SVI<38（HR 2.09（1.39 至 3.16），p<0.001）和 SVI<43（HR 2.05（1.38 至 3.05），p<0.001）。SVI≥43 的生存率与年龄和性别匹配的对照组相似（3 年估计值为 84%，p=0.24）；SVI<43 的生存率明显更差（3 年估计值为 63%，p<0.001）。
在 LG 严重射血分数保留的 AS 中，较低的 SVI 与死亡率呈递增相关。这些发现对 AS 严重程度的分类、高危人群的识别以及随后的治疗具有重要意义。
