Determining the Physiological Threshold for Angina (ORBITA-FIRE): A Double-Blind, Randomized, Placebo-Controlled Study.

Fractional flow reserve (FFR) and nonhyperemic pressure ratios such as resting full-cycle ratio (RFR) are used to guide revascularization.

使用分数流量储备（FFR）和非高血流压力比率（如静息全周期比率RFR）来指导血运重建。

Although these indices correlate with myocardial ischemia, they have never been validated against the onset of angina.

尽管这些指标与心肌缺血相关，但它们从未与心绞痛的发作进行过验证。

The physiological thresholds for angina, FFRangina and RFRangina, angina (FFRangina at rest and during exercise remain undefined.

心绞痛的生理阈值，包括静息和运动时的心绞痛FFR（FFRangina）和心绞痛RFR（RFRangina），目前尚未明确。

Methods

ORBITA-FIRE (Finding the Invasive Threshold for Symptom Relief in Exertional Angina) was a multicenter, double-blind, randomized, placebo-controlledstudy in patients with stable angina and single-vessel coronary artery disease.

ORBITA-FIRE（在劳力性心绞痛中寻找症状缓解的侵入性阈值）是一项多中心、双盲、随机、安慰剂对照的研究，研究对象为稳定型心绞痛患者且单支冠状动脉疾病。

After imaging-guided PCI, an in-stent balloon was incrementally inflated until angina occurred at rest.

在影像引导的经皮冠状动脉介入治疗（PCI）后，支架内球囊被逐步充气直至静息状态下出现心绞痛。

This angina threshold was verified against placebo inflation, and corresponding FFRangina and RFRangina values were recorded at symptom onset.

该心绞痛阈值与安慰剂膨胀进行了验证，并记录了症状发作时相应的FFRangina和RFRangina值。

The protocol was repeated during low- and high-intensity exercise to assess changes in angina thresholds with increasing cardiac workload.

在低强度和高强度运动期间重复该方案，以评估随着心脏工作负荷增加心绞痛阈值的变化。

Results

Sixty-five patients were enrolled (mean age, 63.9±8.7 years; 74% male; 69% hypertensive; 23% diabetic; 91% with Canadian Cardiovascular Society class II-III angina).

共有65名患者入组（平均年龄63.9±8.7岁；74%为男性；69%患有高血压；23%患有糖尿病；91%患有加拿大心血管病学会II-III级心绞痛）。

Median pre-PCI FFR was 0.59 (interquartile range [IQR], 0.46-0.70) and RFR was 0.61 (IQR, 0.40-0.82).

PCI术前中位数FFR为0.59（四分位数间距[IQR]，0.46-0.70），RFR为0.61（IQR，0.40-0.82）。

Median FFRangina at rest was 0.29 (IQR, 0.23-0.35), increasing to 0.38 (IQR, 0.30-0.48) during low-intensity exercise and 0.45 (IQR, 0.36-0.55) during high-intensity exercise.

静息状态下中位数FFR（心绞痛）为0.29（四分位数间距，0.23-0.35），在低强度运动期间增加到0.38（四分位数间距，0.30-0.48），在高强度运动期间增加到0.45（四分位数间距，0.36-0.55）。

RFRangina similarly increased from 0.22 (IQR, 0.16-0.30) at rest to 0.26 (IQR, 0.18-0.36) and 0.32 (IQR, 0.23-0.46) during low- and high-intensity exercise.

RFRangina（心绞痛）同样从静息状态下的0.22（四分位数间距，0.16-0.30）增加到低强度运动期间的0.26（四分位数间距，0.18-0.36）和高强度运动期间的0.32（四分位数间距，0.23-0.46）。

All thresholds were significantly lower than clinical diagnostic cut points (P<0.001).

所有阈值均显著低于临床诊断的临界点（P<0.001）。

Lower FFRangina and RFRangina thresholds were associated with greater symptom reproducibility across rest, low- and high-intensity exercise conditions (FFRangina: P=0.008, P<0.001, P<0.001, respectively; RFRangina: P=0.015, P<0.001, P=0.002, respectively).

较低的FFRangina和RFRangina阈值与在休息、低强度和高强度运动条件下的症状再现性更高相关（FFRangina：分别为P=0.008、P<0.001、P<0.001；RFRangina：分别为P=0.015、P<0.001、P=0.002）。

Lower angina thresholds across all conditions predicted higher baseline angina burden and greater symptom relief with PCI (probability of interaction >0.999).

所有条件下的较低心绞痛阈值预测了较高的基线心绞痛负担以及通过经皮冠状动脉介入治疗（PCI）获得更大的症状缓解（交互概率>0.999）。

Conclusions

Physiological thresholds for angina, FFRangina and RFRangina, are highly individualized, vary with cardiac workload, and are consistently lower than the universal ischemia-based thresholds used to guide revascularization.

心绞痛的生理阈值，包括FFRangina和RFRangina，是高度个性化的，随着心脏工作负荷的变化而变化，并且始终低于用于指导血运重建的普遍性缺血阈值。

These findings support integrating personalized, symptom-linked physiology to refine patient selection and to improve symptomatic response to PCI.

这些发现支持整合个性化的、与症状相关的生理学，以优化患者选择并提高对经皮冠状动脉介入治疗（PCI）的症状反应。