The EXERRT trial: "EXErcise to Regadenoson in Recovery Trial": A phase 3b, open-label, parallel group, randomized, multicenter study to assess regadenoson administration following an inadequate exercise stress test as compared to regadenoson without exercise for myocardial perfusion imaging using a SPECT protocol.

BACKGROUND: This study assessed the non-inferiority and safety of regadenoson administration during recovery from inadequate exercise compared with administration without exercise. METHODS: Patients unable to achieve adequate exercise stress were randomized to regadenoson 0.4 mg either during recovery (Ex-Reg) or 1 hour after inadequate exercise (Regadenoson) (MPI1). All patients also underwent non-exercise regadenoson MPI 1-14 days later (MPI2). The number of segments with reversible perfusion defects (RPDs) detected using single photon emission computerized tomography imaging was categorized. The primary analysis evaluated the majority agreement rate between Ex-Reg and Regadenoson groups. RESULTS: 1,147 patients were randomized. The lower bound of the 95% confidence interval of the difference in agreement rates (-6%) was above the -7.5% non-inferiority margin, demonstrating non-inferiority of Ex-Reg to Regadenoson. Adverse events were numerically less with Ex-Reg (MPI1). In the Ex-Reg group, one patient developed an acute coronary syndrome and another had a myocardial infarction following regadenoson after exercise. Upon review, both had electrocardiographic changes consistent with ischemia prior to regadenoson. CONCLUSIONS: Administering regadenoson during recovery from inadequate exercise results in comparable categorization of segments with RPDs and with careful monitoring appears to be well tolerated in patients without signs/symptoms of ischemia during exercise and recovery.

A randomized, double-blind, placebo-controlled study of the safety and tolerance of regadenoson in subjects with stage 3 or 4 chronic kidney disease.

BACKGROUND: The safety and tolerability of regadenoson, a pharmacologic stress agent that is excreted primarily by the kidneys, were examined in subjects with chronic kidney disease (CKD). METHODS: This multicenter, double-blind, randomized, placebo-controlled study involved men and women, ≥18 years of age, with stage 3 or 4 [estimated glomerular filtration rate (eGFR) 30-59 mL/minute/1.73 m(2) and 15-29 mL/minute/1.73 m(2), respectively] CKD and known or suspected coronary artery disease. Subjects were randomized 2:1 to receive one 10-second intravenous injection of regadenoson 0.4 mg or placebo. The primary outcome measure was the frequency of serious adverse events over 24-h post-dose. RESULTS: The study included 432 subjects with stage 3 (regadenoson n = 287; placebo n = 145) and 72 with stage 4 (regadenoson n = 47; placebo n = 25) CKD. No serious adverse events or deaths were reported over 24-h post-dose. The overall adverse event incidence was higher with regadenoson than placebo (62.6% vs 21.2%; P < .0001). Of the most common adverse events (≥5%) reported by subjects receiving regadenoson, headache (24.9% vs 7.1%), dyspnea (19.2% vs 0.6%), chest discomfort (14.7% vs 0.6%), nausea (14.7% vs 1.2%), flushing (12.0% vs 1.8%), and dizziness (9.6% vs 0.6%) occurred significantly more often (P < .0001) with regadenoson than placebo. There were no trends for clinically meaningful changes in eGFR from baseline to 24-h post-dose in subjects with stage 3 or 4 CKD. CONCLUSIONS: Regadenoson was not associated with any serious or unexpected adverse events in subjects with stage 3 or 4 CKD.

A randomized, double-blind, placebo-controlled study assessing the safety and tolerability of regadenoson in subjects with asthma or chronic obstructive pulmonary disease.

BACKGROUND: Adenosine receptor stress agents for myocardial perfusion imaging (MPI) may cause A(2B) and/or A(3) receptor-mediated bronchoconstriction, of particular concern to physicians testing patients with asthma or chronic obstructive pulmonary disease (COPD). METHODS: A Phase 4, randomized, double-blind study (NCT00862641) assessed the safety of the selective A(2A) receptor agonist, regadenoson, compared with placebo in subjects with asthma or COPD who represented likely candidates for MPI. RESULTS: Overall, 356 and 176 subjects with asthma and 316 and 151 subjects with COPD received regadenoson and placebo, respectively. The percentage of subjects experiencing a >15% decrease in FEV(1) from baseline to any assessment up to 24 hours post-baseline was not statistically significantly different between the regadenoson and the placebo groups in the asthma or COPD stratum. Dyspnea, the most frequent respiratory adverse event, occurred with higher incidence (P < .0001) in the regadenoson group than the placebo group in the asthma (10.7% vs 1.1%) and COPD (18.0% vs 2.6%) strata. No subjects experienced severe bronchoconstriction, although the occurrence of such reactions with adenosine receptor agonists cannot be ruled out, such that caution is advised. CONCLUSIONS: This information may be helpful to physicians selecting a pharmacologic stress agent for MPI in patients with asthma or COPD.

A randomized, multicenter, multivendor study of myocardial perfusion imaging with regadenoson CT perfusion vs single photon emission CT.

BACKGROUND: Myocardial CT perfusion (CTP) is a promising tool for the detection of myocardial ischemia. We hypothesize that regadenoson CTP is noninferior to regadenoson single photon emission CT (SPECT) for detecting or excluding myocardial ischemia. METHODS: Patients (men ≥ 45 years; women ≥ 50 years) with known or suspected coronary artery disease (n = 124) were randomized to 1 of 2 diagnostic sequences: rest and regadenoson SPECT on day 1, then regadenoson CTP and rest CTP (and coronary CT angiography [CTA]) (CTA; same acquisition) on day 2 or regadenoson CTP and rest CTP (and CTA) on Day 1, then rest and regadenoson SPECT on day 2. Scanning platforms included 64-, 128-, 256-, and 320-slice systems. The primary analysis examined the agreement rate between CTP and SPECT for detecting or excluding reversible ischemia in ≥ 2 myocardial segments as assessed by independent, blinded readers. RESULTS: Complete and interpretable CTP and SPECT scans were obtained for 110 patients. Regadenoson CTP was noninferior to SPECT for detecting or excluding reversible ischemia with an agreement rate of 0.87 (95% confidence interval [CI], 0.77-0.97) and sensitivity and specificity of 0.90 (95% CI, 0.71-1.00) and 0.84 (95% CI, 0.77-0.91), respectively. The agreement rate for detecting or excluding ≥ 1 fixed defects by regadenoson CTP and SPECT was 0.86 (95% CI, 0.74-0.98). With SPECT as the reference standard, the diagnostic accuracies for detecting or excluding ischemia by regadenoson CTP and CTA alone were 0.85 (95% CI, 0.78-0.91) and 0.69 (95% CI, 0.60-0.77), respectively. CONCLUSIONS: This study establishes the noninferiority of regadenoson CTP to SPECT for detecting or excluding myocardial ischemia.

Regadenoson-stress myocardial CT perfusion and single-photon emission CT: rationale, design, and acquisition methods of a prospective, multicenter, multivendor comparison.

Pharmacologic stress myocardial CT perfusion (CTP) has been reported to be a viable imaging modality for detection of myocardial ischemia compared with single-photon emission CT (SPECT) in several single-center studies. However, regadenoson-stress CTP has not previously been compared with SPECT in a multicenter, multivendor study. The rationale and design of a phase 2, randomized, cross-over study of regadenoson-stress myocardial perfusion imaging by CTP compared with SPECT are described herein. The study will be conducted at approximately 25 sites by using 6 different CT scanner models, including 64-, 128-, 256-, and 320-slice systems. Subjects with known/suspected coronary artery disease will be randomly assigned to 1 of 2 imaging procedure sequences; rest and regadenoson-stress SPECT on day 1, then regadenoson-stress CTP and rest CTP/coronary CT angiography (same acquisition) on day 2; or regadenoson-stress CTP and rest CTP/CT angiography on day 1, then rest and regadenoson-stress SPECT on day 2. The prespecified primary analysis examines the agreement rate between CTP and SPECT for detecting or excluding ischemia (≥2 or 0-1 reversible defects, respectively), as assessed by 3 independent blinded readers for each modality. Non-inferiority will be indicated if the lower boundary of the 95% CI for the agreement rate is within 0.15 of 0.78 (the observed agreement rate in the regadenoson pivotal trials). The protocol described herein will support the first evaluation of regadenoson-stress CTP by using multiple scanner types compared with SPECT.