Abstract
Background
To identify and stratify coronary artery disease (CAD) non-invasively, cardiovascular magnetic resonance (CMR) derived perfusion imaging holds a class Ia recommendation.
As Gold standard, hyperemia is induced by an intravenous application of adenosine in a body weight adapted dosage over a constant time. However, adenosin has two disadvantages: 1.) efficacy of adenosine to induce maximal hyperemia via peripheral line is imperfect and 2.) additional adenosine specific effects exclude patients having comorbidities (e.g. AV-blocks and obstructive lung disease). Fortunately, regadenoson as aselective A2A-receptor agonist has the main advantages of being easier to handle (bolus application) and to be not restricted to patients without specific comorbidities. However, there is a lack of comprehensive data on the prognostic value of regadenoson perfusion CMR to predict clinical endpoints. To assess the predictive value of regadenoson perfusion CMR, our hypothesis was, that a “negative” ischemia test result by regadenoson-CMR predicted freedom from MACE at 12 month.
Methods
676 patients, with known or suspected CAD with intermediate risk were retrospectively analyzed from May 2015 till December 2016. Cardiovascular risk factors (CVRF) like age, sex, arterial hypertension, dis-/hyperlipidemia, cigarette smoking status and diabetes were documented. All included patients received perfusion CMR (Philips 1.5 Tesla) with regadenoson (0.4 mg) and a positive ischemia test was defined as perfusion defects in ≥1,5 cardiac segments (using the 17-segment model). Major cardiovascular events (MACE) were defined as cardiovascular death, rehospitalisation due to myocardial infarction and rehospitalisation due to revascularization. The follow-up time was 12 month.
Results
80,3% (n=543) of all analyzed patients showed negative ischemia testing in CMR and were thus followed up for 12 month. From these patients, 284 (52,3%) had a pre-existing coronary artery disease. The mean age regarding only the patients with negative ischemia was 66 years (65% male and 35% female) with 1,35±1,03 CVRF. The primary endpoint (MACE) occurred in 6 patients (1,1%): 3 (0,6%) died due to cardiovascular events, 1 (0,2%) suffered from a myocardial infarction and 2 (0,4%) received coronary revascularization. Consequently, an event-free survival was correctly predicted in 98,9% of all patients. No undesirable adverse reactions have appeared.
Conclusion
Regadenoson-CMR predicts a very low MACE-rate and an event-free survival in 98,9% in over 500 patients. In our study, Regadenoson was well tolerated and no side effects were reported.
Quantitative characterization of myocardial infarction by cardiovascular magnetic resonance predicts future cardiovascular events in patients with ischemic cardiomyopathy
