Objectives The objective of this study was to determine the prognostic value of combined measures of B-type natriuretic peptide (BNP) and high-sensitivity cardiac troponin T (hsTnT) in patients with low-flow, low-gradient aortic stenosis (LF-LG AS) who had either a preserved or reduced left ventricular ejection fraction (LVEF).

Background An elevated BNP level is associated with increased risk of mortality in patients with LF-LG AS. The incremental prognostic value of hsTnT in these patients is unknown.

Methods Ninety-eight patients (74 ± 10 years; 75% men) with LF-LG AS (LVEF <50% and/or stroke volume index <35 ml/m², mean gradient <40 mm Hg, indexed aortic valve area <0.6 cm²/m²) who were prospectively enrolled in the TOPAS (Truly or Pseudo-Severe Aortic Stenosis) study were included. The cohort was divided into 3 groups according to BNP and hsTnT levels: group A: BNP <550 pg/ml and hsTnT <15 ng/l; group B: BNP ≥550 pg/ml or hsTnT ≥15 ng/l; and group C: BNP ≥550 pg/ml and hsTnT ≥15 ng/l. The primary endpoint was all-cause mortality.

Results Twenty-seven patients (27%) were in group A, 39 (40%) were in group B, and 32 (33%) were in group C. During a median follow-up of 2.8 years, 43 patients died. Two-year mortality was higher in group C (41 ± 9%) than in group B (23 ± 7%) and group A (5 ± 4%) (p = 0.002). In group B, there was no significant difference in 2-year mortality rates between the subgroup with hsTnT ≥15 ng/l (n = 29) and the subgroup with BNP ≥550 pg/ml (n = 10) (26 ± 9% vs. 11 ± 10%, respectively; p = 0.21). In multivariable analysis adjusted for age, type of treatment (aortic valve replacement vs. conservative therapy), coronary artery disease, and LVEF, being in group C remained independently associated with an increased risk of mortality (hazard ratio [HR]: 4.25; p = 0.023), and group B tended to have higher mortality (HR: 3.63; p = 0.058) compared with group A.

Conclusions This study demonstrated the usefulness of combined measures of BNP and hsTnT to enhance risk stratification in patients with LF-LG AS. Patients with elevation of both BNP and hsTnT had a markedly increased risk of mortality. (Multicenter Prospective Study of Low-Flow Low-Gradient Aortic Stenosis [TOPAS]; NCT01835028)

目的本研究的目的是确定B型钠尿肽（BNP）和高敏感性心肌肌钙蛋白T（hsTnT）联合测量对低流量，低梯度主动脉瓣狭窄（LF-LG）患者的预后价值AS）左室射血分数（LVEF）保持或降低。

背景升高的BNP水平与LF-LG AS患者的死亡风险增加相关。hsTnT在这些患者中增加的预后价值尚不清楚。

方法LF-LG AS（LVEF <50％和/或每搏量指数<35 ml / m ²，平均梯度<40 mm Hg，主动脉瓣面积< 90％）的98例患者（74±10岁； 75％男性）0.6 cm ² / m ²）包括前瞻性参加TOPAS（真正或假性严重主动脉瓣狭窄）研究的患者。根据BNP和hsTnT水平将队列分为3组：A组：BNP <550 pg / ml和hsTnT <15 ng / l； BNP <550 pg / ml和hsTnT <15 ng / l。B组：BNP≥550pg / ml或hsTnT≥15ng / l；C组：BNP≥550pg / ml，hsTnT≥15ng / l。主要终点是全因死亡率。

结果A组27例（27％），B组39例（40％），C组32例（33％）。在2.8年的中位随访中，有43例患者死亡。C组（41±9％）的两年死亡率高于B组（23±7％）和A组（5±4％）（p = 0.002）。在B组中，hsTnT≥15 ng / l的亚组（n = 29）和BNP≥550 pg / ml的亚组（n = 10）之间的2年死亡率无显着差异（26±9％）分别为11±10％； p = 0.21）。在根据年龄，治疗类型（主动脉瓣置换与保守治疗），冠状动脉疾病和LVEF进行校正的多变量分析中，C组仍与死亡风险增加独立相关（危险比[HR]：4.25； p = 0.023），并且B组的死亡率高于A组（HR：3.63； p = 0.058）。

结论这项研究证明了结合BNP和hsTnT的措施可增强LF-LG AS患者的危险分层。BNP和hsTnT升高的患者死亡风险显着增加。（低流量低梯度主动脉瓣狭窄[TOPAS]的多中心前瞻性研究； NCT01835028）