RESUMO
The aim of this study was to examine whether the heart rate response to adenosine differs after 12 hours [Good control (Good-C)] versus 24 hours [Excellent control (Exc-C)] of caffeine abstinence in adenosine stress thallium-201 (TL) myocardial perfusion imaging (MPI). Patients (n=729) with suspected ischemic heart disease underwent adenosine TL-MPI after 12 (n=226) and 24 (n=503) hours of caffeine abstinence. There was not significant differences between the heart rate of Exc-C and Good-C in 0-2 min after adenosine infusion (0 min 63.7±9.5 versus 63.7±10.0, 1 min 66.4±10.6 versus 65.3±10.5, 2 min 72.3±11.2 versus 70.6±11.4). The heart rate of Exc-C was higher compared to Good-C in 3-6 min after adenosine infusion (3 min 75.6 ±11.7 versus 73.3±11.6 p=0.013, 4 min 79.2±12.9 versus 76.7±12.2 p=0.012, 5 min 79.4±12.6 versus 76.8±12.4 p=0.009, 6 min 79.4±12.5 versus 77.0±12.3 p=0.016). Therefore, the longer caffeine abstinence, namely 24 hours self-restraint, is effective in adenosine TL-MPI.
