Mutha Vivek, Asrar Ul Haq Muhammad, Van Gaal William J
Department of Cardiology , The Northern Hospital , Melbourne, Victoria , Australia.
Department of Cardiology , The Northern Hospital , Melbourne, Victoria , Australia ; Department of Medicine , University of Melbourne , Melbourne, Victoria , Australia.
Open Heart. 2014 Aug 4;1(1):e000060. doi: 10.1136/openhrt-2014-000060. eCollection 2014.
Intravenous adenosine is used to minimise the coronary micro-resistance to achieve maximal hyperaemia along with nitrates for optimal fractional flow reserve (FFR) measurements. We hypothesise that caffeine, being a competitive inhibitor of adenosine, would influence adenosine-mediated FFR readings.
Consecutive patients undergoing angiogram and FFR measurements were enrolled after abstaining from caffeine for 24 h. Patients with any contraindications to intravenous adenosine or caffeine were excluded. FFR measurements were taken using nitrates and adenosine pre and post 4 mg/kg intravenous caffeine administration and results were compared.
10 patients were analysed (80% men, age 59.9±9.4, weight 87.5±15.6). Baseline caffeine levels were undetectable in all patients and increased significantly postintravenous caffeine administration (16.4±5.5 μg/mL). Baseline preadenosine FFR values were similar before and after caffeine administration (0.91±0.06 vs 0.91±0.07; p=0.41). Postadenosine FFR readings were 0.79±0.07, which increased non-significantly to 0.82±0.11 postcaffeine (p=0.15). Two significant FFR readings (≤0.8) changed to non-significant after caffeine administration (0.77-0.93 and 0.8-0.91).
Caffeine may affect FFR results in some patients. Larger studies are warranted to clarify the extent and magnitude of caffeine/adenosine interaction particularly due to ubiquitous nature of caffeine and increasing importance of FFR in clinical practice.
静脉注射腺苷用于最小化冠状动脉微血管阻力，与硝酸盐一起实现最大充血，以进行最佳的血流储备分数（FFR）测量。我们假设咖啡因作为腺苷的竞争性抑制剂，会影响腺苷介导的FFR读数。
连续接受血管造影和FFR测量的患者在停用咖啡因24小时后入组。排除有静脉注射腺苷或咖啡因任何禁忌症的患者。在静脉注射4mg/kg咖啡因前后，使用硝酸盐和腺苷进行FFR测量，并比较结果。
分析了10例患者（80%为男性，年龄59.9±9.4岁，体重87.5±15.6kg）。所有患者的基线咖啡因水平均未检测到，静脉注射咖啡因后显著升高（16.4±5.5μg/mL）。咖啡因给药前后的基线腺苷前FFR值相似（0.91±0.06对0.91±0.07；p=0.41）。腺苷后FFR读数为0.79±0.07，咖啡因后非显著增加至0.82±0.11（p=0.15）。两次显著的FFR读数（≤0.8）在咖啡因给药后变为不显著（0.77 - 0.93和0.8 - 0.91）。
咖啡因可能会影响一些患者的FFR结果。有必要进行更大规模的研究，以阐明咖啡因/腺苷相互作用的程度和大小，特别是由于咖啡因的普遍存在以及FFR在临床实践中的重要性日益增加。
