Cardiovascular Research, The Division of Cardiovascular Diseases, Mayo Clinic, Southwest Rochester, MN 55905, USA.
Eur Heart J. 2012 Jul;33(14):1742-9. doi: 10.1093/eurheartj/ehs135. Epub 2012 May 29.
The pathophysiology of heart failure with preserved ejection fraction (HFpEF) is complex but increased left ventricular (LV) diastolic stiffness plays a key role. A load-independent, non-invasive, direct measure of diastolic stiffness is lacking. The diastolic wall strain (DWS) index is based on the linear elastic theory, which predicts that impaired diastolic wall thinning reflects resistance to deformation in diastole and thus, increased diastolic myocardial stiffness. The objectives of this community-based study were to determine the distribution of this novel index in consecutive HFpEF patients and healthy controls, define the relationship between DWS and cardiac structure and function and determine whether increased diastolic stiffness as assessed by DWS is predictive of the outcome in HFpEF.
Consecutive HFpEF patients (n = 327, EF ≥ 50%) and controls (n = 528) from the same community were studied. Diastolic wall strain was lower in HFpEF (0.33 ± 0.08) than in controls (0.40 ± 0.07, P < 0.001). Within HFpEF, those with DWS ≤ median (0.33) had higher LV mass index, relative wall thickness, E/e', Doppler-estimated LV end-diastolic pressure to LV end-diastolic volume ratio, left atrial volume index, and brain natriuretic peptide (BNP) levels than those with DWS > median. Heart failure with preserved ejection fraction patients with DWS ≤ median had higher rate of death or HF hospitalization than those with DWS > median (P = 0.003) even after the adjustment for age, gender, log BNP, LV geometry, or log E/e' (P < 0.01).
These data suggest that DWS, a simple index, is useful in assessing diastolic stiffness and that more advanced diastolic stiffness is associated with worse outcomes in HFpEF.
射血分数保留的心力衰竭(HFpEF)的病理生理学较为复杂,但左心室(LV)舒张僵硬增加起着关键作用。目前缺乏一种独立于负荷、非侵入性的舒张僵硬的直接测量方法。舒张壁应变(DWS)指数基于线性弹性理论,该理论预测舒张期壁变薄受损反映了舒张期变形的阻力,因此,舒张心肌僵硬增加。本社区研究的目的是确定该新型指数在连续 HFpEF 患者和健康对照者中的分布,确定 DWS 与心脏结构和功能的关系,并确定 DWS 评估的舒张僵硬增加是否可预测 HFpEF 的结局。
本研究纳入了来自同一社区的连续 HFpEF 患者(n = 327,EF ≥ 50%)和对照组(n = 528)。HFpEF 患者的舒张壁应变(0.33 ± 0.08)低于对照组(0.40 ± 0.07,P < 0.001)。在 HFpEF 中,DWS 低于中位数(0.33)的患者具有更高的 LV 质量指数、相对壁厚度、E/e'、多普勒估计的 LV 舒张末期压力与 LV 舒张末期容积比、左心房容积指数和脑利钠肽(BNP)水平高于 DWS 高于中位数的患者。DWS 低于中位数的 HFpEF 患者的死亡率或 HF 住院率高于 DWS 高于中位数的患者(P = 0.003),即使在校正年龄、性别、log BNP、LV 几何形状或 log E/e'后(P < 0.01)。
这些数据表明,DWS 是一种简单的指标,可用于评估舒张僵硬,并且更严重的舒张僵硬与 HFpEF 患者的预后更差相关。