096 REGADENOSON IN EUROPE: FIRST- YEAR EXPERIENCE OF REGADENOSON STRESS COMBINED WITH SUBMAXIMAL EXERCISE IN PATIENTS UNDERGOING MPS

Abstract

Purpose: Regadenoson is a selective adenosine A2a receptor agonist that was developed to avoid the side effects associated with the unselective adenosine receptor agonists. Since approval in Europe in 2011 regadenoson has become the default form of stress at our institution. The aim of this study was to assess its side effect profile and tolerability in consecutive patients undergoing MPS between July 2011 and July 2012. Methods: We studied 1764 consecutive patients referred to our institution for clinically indicated MPS. Clinical, stress and imaging data were recorded prospectively and analysed using the Excel data analysis toolpak and SPSS. Symptoms during stress were defined as mild, moderate or severe. An adverse event was defined as any symptom that persisted for more than 30 minutes or that required investigation or treatment. Results: Of 1764 patients, 1581 (90%) received regadenoson combined with sub-maximal exercise unless contraindicated. Symptoms were common (63%) but transient and well-tolerated. The severity of symptoms was recorded in most of the patients as mild (84%). Dyspnoea (36%) and chest discomfort (12%) were the commonest side effects. Adverse events were reported in 8 (0.5%) patients, 7 of these thought to be vaso-vagal. Three events were moderate and two severe, the latter with sinus arrest and asystole lasting 30 and 10 seconds and requiring CPR. All patients recovered fully without sequelae. There were no deaths, myocardial infarction or hospital admissions. Twohundred and six asthma/COPD patients (12%) received regadenoson without bronchospasm or any other major side effect. Conclusion: We have studied 1764 stress tests for MPS over a twelvemonth period in order to assess the symptom profile of regadenoson in the largest European cohort to date. Regadenoson combined with exercise is well tolerated, notably also in patients with asthma/COPD. The majority of adverse events were vaso-vagal episodes without sequelae. There is no clear direct mechanism by which regadenoson might cause vaso-vagal syncope.