A high-dose adenosine protocol (up to 210 mcg/kg/min) was well tolerated and achieved an adequate haemodynamic response in 89% (16 of 18) of patients who had an inadequate response to the standard dose.
Cohort (n=98)
No
Does a high-dose adenosine protocol safely improve haemodynamic response in patients with known or suspected CAD who have an inadequate response to standard-dose adenosine during CMR perfusion imaging?
A high-dose adenosine protocol (up to 210 mcg/kg/min) is safe, well-tolerated, and effectively improves haemodynamic response in patients undergoing CMR perfusion imaging who fail to respond to the standard dose.
INTRODUCTION: Adenosine is the most widely used vasodilator stress agent for cardiovascular magnetic resonance (CMR) perfusion studies. With the standard dose of 140 mcg/kg/min some patients fail to demonstrate characteristic haemodynamic changes: a significant increase in heart rate (HR) and mild decrease in systolic blood pressure (SBP). Whether an increase in the rate of adenosine infusion would improve peripheral and, likely, coronary vasodilatation in those patients is unknown. The aim of the present study was to assess the tolerance and safety of a high-dose adenosine protocol in patients with inadequate haemodynamic response to the standard adenosine protocol when undergoing CMR perfusion imaging. METHODS: 98 consecutive patients with known or suspected coronary artery disease (CAD) underwent CMR perfusion imaging at 1.5 Tesla. Subjects were screened for contraindications to adenosine, and an electrocardiogram was performed prior to the scan. All patients initially received the standard adenosine protocol (140 mcg/kg/min for at least 3 minutes). If the haemodynamic response was inadequate (HR increase 65 years and ejection fraction < 57% were the only independent predictors of blunted haemodynamic responsiveness to adenosine. CONCLUSIONS: A substantial number of patients do not show adequate peripheral haemodynamic response to standard-dose adenosine stress during perfusion CMR imaging. Age and reduced ejection fraction are predictors of inadequate response to standard dose adenosine. A high-dose adenosine protocol (up to 210 mcg/kg/min) is well tolerated and results in adequate haemodynamic response in nearly all patients.
Karamitsos et al. (Fri,) conducted a cohort in Coronary artery disease (n=98). High-dose adenosine vs. Standard dose adenosine (140 mcg/kg/min) was evaluated on Adequate haemodynamic response (HR increase ≥ 10 bpm or SBP decrease ≥ 10 mmHg). A high-dose adenosine protocol (up to 210 mcg/kg/min) was well tolerated and achieved an adequate haemodynamic response in 89% (16 of 18) of patients who had an inadequate response to the standard dose.