Lyngholm Ann Marie, Pedersen Begitte H, Petersen Lars J
Department of Clinical Physiology, Viborg Hospital, Viborg, Denmark.
Nucl Med Commun. 2008 Sep;29(9):759-63. doi: 10.1097/MNM.0b013e3283031af8.
Intestinal activity at the inferior myocardial wall represents an issue for assessment of myocardial perfusion imaging (MPI) with 99mTc-labelled tracers. The aim of this study was to investigate the effect of time and food on upper abdominal activity in 99mTc-tetrofosmin MPI.
The study population consisted of 152 consecutive patients referred for routine MPI. All patients underwent 2-day stress-rest 99mTc-tetrofosmin single-photon emission computed tomography MPI. Before stress testing, patients were randomized in a factorial design to four different regimens. Group A: early scan (image acquisition initiated within 15 min after injection of the tracer) and no food; group B: early scan and food (two pieces of white bread with butter and a minimum of 450 ml of water); group C: late scan (image acquisition 30-60 min after injection of the tracer) and no food; and group D: late and scan with food. Patients underwent standard bicycle exercise or pharmacological stress test. The degree of upper abdominal activity was evaluated by trained observers blinded to the randomization code. The primary endpoint was the proportion of accepted scans in the intention-to-treat population in stress MPI.
The results showed statistical significant impact on both time and food on upper abdominal activity. The primary endpoint showed that the acceptance rate improved from 55% in group A to 100% success rate in group D. An early scan reduced the acceptance rate by 30% versus a late scan [hazard ratio 0.70, 95% confidence interval 0.58-0.84; P<0.0001], whereas the addition of food improved the success rate versus no food by 27% (hazard ratio 1.27, 95% confidence interval 1.07-1.51; P=0.006). No significant interaction between food and time was observed. An analysis of accepted scans according to the actual scan time and food consumption confirmed the findings of the intention-to-treat analysis. In addition, similar findings were seen in 116 of 152 patients with a rest MPI (success rate of 53% in group A vs. 96% in group D).
A combination of solid food and water administered after injection of the tracer and delayed image acquisition led to significant and clinically relevant decrease of interfering upper abdominal activity in 99mTc-tetrofosmin MPI.
心肌下壁的肠道活动是使用99mTc标记示踪剂评估心肌灌注显像（MPI）的一个问题。本研究的目的是探讨时间和食物对99mTc-替曲膦MPI中上腹部活动的影响。
研究人群包括152例连续接受常规MPI检查的患者。所有患者均接受为期2天的负荷-静息99mTc-替曲膦单光子发射计算机断层显像MPI检查。在负荷试验前，患者按照析因设计随机分为四种不同方案。A组：早期扫描（注射示踪剂后15分钟内开始图像采集）且禁食；B组：早期扫描且进食（两片涂黄油的白面包和至少450毫升水）；C组：晚期扫描（注射示踪剂后30 - 60分钟进行图像采集）且禁食；D组：晚期扫描且进食。患者接受标准的自行车运动或药物负荷试验。由对随机分组代码不知情的训练有素的观察者评估上腹部活动程度。主要终点是负荷MPI意向性治疗人群中可接受扫描的比例。
结果显示时间和食物对上腹部活动均有统计学显著影响。主要终点表明，接受率从A组的55%提高到D组的100%成功率。早期扫描与晚期扫描相比，接受率降低了30%[风险比0.70，95%置信区间0.58 - 0.84；P < 0.0001]，而进食与禁食相比，成功率提高了27%（风险比1.27，95%置信区间1.07 - 1.51；P = 0.006）。未观察到食物和时间之间的显著交互作用。根据实际扫描时间和食物摄入情况对可接受扫描进行的分析证实了意向性治疗分析的结果。此外，在152例进行静息MPI的患者中的116例也观察到了类似结果（A组成功率为53%，D组为96%）。
在注射示踪剂后给予固体食物和水并延迟图像采集，可显著且在临床上减少99mTc-替曲膦MPI中干扰性上腹部活动。
