Regadenoson stress echocardiography: a road ahead

Abstract Introduction Drugs used in stress echocardiography (SE) have important limitations due to side effects and contraindications. Since its approval in 2008, Regadenoson has seen a significant increase in usage. This is largely attributed to its good safety profile and diagnostic accuracy, making it the preferred drug for stress tests in many European centers. However, despite its expanding use and major advantages, current guidelines don't place it as the first choice for SE, probably because the reported experience with this drug remains limited. The aim of the present study was to assess the safety and short-medium term prognosis of patients who underwent Regadenoson SE. Methods Retrospective observational study. Patients who underwent Regadenoson SE between 2017 and 2023 were included. Safety was assessed by monitoring immediate adverse effects following Regadenoson infusion and the need for using an antidote (Aminophylline). A positive test result was defined by the occurrence of any of the following: wall motion abnormalities, left ventricle dilatation, electrocardiographic changes or symptoms of ischemia. During the follow up, we registered the incidence of ischaemic events (admission for unstable angina, acute myocardial infarction (AMI) or cardiovascular (CV) death) and other CV events such as admission for heart failure (HF) and stroke. Additionally, we evaluated patients in both groups who underwent coronary angiography (by computerized tomography or coronary catheterization) during the follow up period. The groups with negative SE (NSE) and positive SE (PSE) were compared. Results The total number of patients was 344, with a median follow up of 29 months. Basal population characteristics and events by group (NSE and PSE) are shown in Figure 1. We needed to use the antidote in only one case, because of ventricular bigeminism, with no other major adverse effects reported. SE was positive in 37 (11%) patients. In this group, patients were more likely to present ischaemic events (16% vs. 3%, p<0.01) and admissions for HF (24% vs. 5%, p <0.01), compared to the NSE one. In those who underwent coronary angiography, revascularization was needed in 14 patients of the PSE group, and only in 7 of the NSE group (38% vs 2%, p < 0.05). The indications for these last cases were persistent angina in 5 patients (2 of them with history of coronary artery disease) and revascularization following an AMI in 2 patients. (Figure 2). Conclusions The probability of an ischaemic event after a negative Regadenoson SE remains very low, unlike positive studies. Regadenoson SE showed to be both safe in assessing ischemic cardiomyopathy and very useful for its prognostic value. These findings encourage its expanding use in the stress echo lab.