Slow recruitment and interim analysis results

Purpose: The investigators plan to test a newly FDA approved pharmacologic stress agent, Regadenoson, in conjunction with atropine in the use of stress echocardiography for the diagnosis of coronary artery disease. The selective nature of Regadenoson allows for its use in patients with contraindications to the currently used drug, Adenosine, which is non-selective. Furthermore, the proposed protocol can be completed faster and without radiation exposure than the current protocol with adenosine.

Design: This is a prospective study evaluating people with no prior diagnosis of coronary disease with a prior stress test and are scheduled for cardiac catheterization. Patients who meet inclusion criteria will undergo regadenoson-atropine echocardiography protocol prior to their catheterization. The study will be interpreted by two independent readers blinded to the catheterization results. The sensitivity, specificity, positive and negative predictive values of the regadenoson-atropine study will be then be calculated using the coronary angiogram as a gold standard.

Inclusion Criteria:

1. Age > 18 years old
2. Able to provide consent
3. Scheduled for cardiac catheterization either with or without a prior functional stress imaging study

Exclusion Criteria:

1. Any history of acute myocardial infarction, prior PCI in last 3 months, bypass surgery,
2. History of greater than first degree AV block, sick sinus syndrome in patients
3. Patients with a pacemaker/LBBB
4. History on uncontrolled arrhythmias
5. Patients with significant pulmonary disease, known or suspected bronchoconstrictive or bronchospastic lung disease or other hypersensitivity to adenosine
6. History of cardiac transplantation, hypertrophic cardiomyopathy, acute myocarditis or pericarditis, severe valvular heart disease
7. Hemodynamically unstable patients
8. Dipyridamole use within 30 hours, consumption of methylxanthines (e.g., tea, coffee, caffeinated soft drinks, chocolate, or cocoa) within 12 hours, or use of sublingual nitroglycerin within 2 hours
9. History of glaucoma or obstructive uropathy
10. Allergy or hypersensitivity to atropine
11. Participation in another investigational drug study within 1 month or participation in any previous regadenoson trial
12. Pregnancy, breast feeding, or not using an acceptable method of birth control (if premenopausal)
13. . History of end-stage renal disease on hemodialysis or peritoneal dialysis

Adverse Events collection occurred from consent to conclusion of post-monitoring period. A total time of 45 minutes.

The major limitations of our study was slow patient recruitment leading to premature termination of the study. Based on our observations of enrolled patients, we do not believe that additional recruitment would have changed the results/conclusions.