Division of Cardiology, Azienda Ospedaliera-Universitaria "Maggiore della Carità", Eastern Piedmont University, Novara, Italy.
Division of Cardiology, Azienda Ospedaliera-Universitaria "Maggiore della Carità", Eastern Piedmont University, Novara, Italy; ASST Santi Paolo e Carlo, Milano, Italy.
Int J Cardiol. 2019 Jun 1;284:16-21. doi: 10.1016/j.ijcard.2018.09.088. Epub 2018 Oct 2.
Fractional Flow Reserve (FFR) is currently indicated as a first line strategy for the functional assessment of intermediate coronary stenoses. However, the protocol for inducing hyperemia still lacks standardization. Intracoronary adenosine boli, with a progressive increase to high-dosage, have been proposed as a sensitive and accurate strategy for the classification of coronary stenoses, although being potentially affected by the achievement of plateau of the effect and by a less prolonged and stable hyperemia as compared to intravenous administration. Therefore, the aim of the present study was to define the conditioning parameters and assess the impact of increasing-dose intracoronary adenosine on peak hyperemia duration in patients undergoing FFR for intermediate coronary stenoses.
FFR was assessed in patients with intermediate (40 to 70%) lesions by pressure-recording guidewire (Prime Wire, Volcano), after induction of hyperemia with intracoronary boli of adenosine (from 60 to 1440 μg, with dose doubling at each step). Hyperemic duration was defined as the time for the variation form minimum FFR ± 0.02 and time to recovery till baseline values.
We included 87 patients, undergoing FFR evaluation of 101 lesions. Mean peak hyperemia duration and time to recovery significantly increased with adenosine doses escalation (p = 0.02 and p < 0.001). Peak hyperemia duration and time to recovery with 1440 μg adenosine were 14.5 ± 12.6 s and 45.2 ± 30.7 s, respectively. Hyperemia duration was not related to Quantitative Coronary Angiography (QCA) parameters or FFR values. In fact, a similar increase in the time of hyperemic peak was noted when comparing patients with positive or negative FFR (p = 0.87) or patients with lesions < or ≥20 mm (p = 0.92) and lesions involving left main coronary or proximal left anterior descending artery (LAD) (p = 0.07). A linear relationship was observed between time to recovery and FFR variations, with a greater time to baseline required in patients with FFR ≤ 0.80 (p = 0.003) and in lesions ≥ 20 mm (p = 0.006), but not in LAD/LM lesions (p = 0.55).
The present study shows a progressive raise in the duration of peak hyperemia and time to recovery, after the administration of increasing doses of intracoronary adenosine for the assessment of FFR. Therefore, considering the potential advantages of a high-dose adenosine protocol, allowing a more prolonged hyperemia and a more precise and reliable measurement of FFR, further larger studies with such FFR strategy should certainly be advocated to confirm its safety and benefits, before its routinely use recommendation.
分数血流储备（FFR）目前被认为是评估中度冠状动脉狭窄的功能的一线策略。然而，诱导充血的方案仍缺乏标准化。虽然与静脉内给药相比，冠状动脉内腺苷弹丸，随着剂量的增加到高剂量，已经被提出作为一种敏感和准确的策略来分类冠状动脉狭窄，但可能受到效应平台的实现和更短暂和稳定的充血的影响。因此，本研究的目的是定义递增剂量冠状动脉内腺苷对接受 FFR 检查的中度冠状动脉狭窄患者的峰值充血持续时间的影响。
通过压力记录导丝（Prime Wire，Volcano）在接受中度（40 至 70%）病变的患者中进行 FFR 评估，在使用冠状动脉内腺苷弹丸诱导充血后（从 60 至 1440μg，每次剂量加倍）。充血持续时间定义为从最小 FFR 变化的时间±0.02 和恢复到基线值的时间。
我们纳入了 87 名患者，对 101 个病变进行了 FFR 评估。随着腺苷剂量的增加，峰值充血持续时间和恢复时间显著增加（p=0.02 和 p<0.001）。使用 1440μg 腺苷时，峰值充血持续时间和恢复时间分别为 14.5±12.6s 和 45.2±30.7s。充血持续时间与定量冠状动脉造影（QCA）参数或 FFR 值无关。事实上，在比较 FFR 为阳性或阴性的患者（p=0.87）或病变<或≥20mm 的患者（p=0.92）以及涉及左主干或近端左前降支（LAD）的病变患者时，也观察到充血峰值增加相似（p=0.07）。在恢复到基线的时间和 FFR 变化之间观察到线性关系，FFR≤0.80 的患者（p=0.003）和病变≥20mm 的患者（p=0.006）需要更多的时间恢复到基线，但在 LAD/LM 病变患者中没有（p=0.55）。
本研究表明，在评估 FFR 时，给予递增剂量的冠状动脉内腺苷后，峰值充血持续时间和恢复到基线的时间逐渐增加。因此，考虑到高剂量腺苷方案的潜在优势，允许更持久的充血和更精确、更可靠的 FFR 测量，进一步的更大规模的研究采用这种 FFR 策略，当然应该提倡，以确认其安全性和益处，然后再推荐其常规使用。
