Stress Echo Ultrasound Contrast in an Urban Safety Net Hospital to Refine Ischemia Evaluation

Inclusion criteria

• Patients must meet all of the following inclusion criteria to be eligible for participation in this study:

• Males or females aged ≥ 18 years
• Evaluated for symptoms of chest discomfort or ischemic equivalent
• Clinical indication for stress imaging, defined as one of the following clinical risk estimates for CAD based upon the Diamond and Forrester classification7:

• Intermediate pretest probability of CAD and electrocardiogram (ECG) is clinically interpretable and patient is able to exercise
• Intermediate pretest probability of CAD and ECG is clinically interpretable or patient is unable to exercise
• High pretest probability of CAD regardless of ECG interpretability and ability to exercise
• Willing and able to provide written informed consent to participate in this study
• Agrees to remain under observation (e.g., inpatient or observational status) until all study procedures from the hospital stay are completed, and to complete a 30-day follow up call

Exclusion criteria

• Patients who meet any of the following exclusion criteria are not to be enrolled in this study:

• Documented medical history or discovery during screening and/or admission of any of the following:

• Severe aortic or mitral stenosis
• Significant resting left ventricular outflow tract obstruction (velocity > 3 cm/s)
• Mobile left ventricular apical thrombus
• Acute pericarditis or pericardial tamponade
• Ascending or thoracic aortic aneurysm that is not stable or meets surgical criteria
• Acute decompensated congestive heart failure
• Established severe left ventricular systolic dysfunction (left ventricular ejection fraction < 35%)
• Definite acute coronary syndrome (e.g., unstable angina, acute myocardial infarction) as confirmed by elevated Troponin I (>0.6 ng/L) on two successive measurements or ECG changes diagnostic for unstable angina (e.g. localized ST changes) in conjunction with clinical appraisal
• Any of the following other abnormalities on the ECG at screening:

• Paced ventricular rhythm or complete left bundle branch block
• Uncontrolled arrhythmias defined by frequent premature ventricular complexes (PVCs) > 10/minute, non-sustained ventricular tachycardia, or atrial fibrillation with rapid ventricular response
• 2nd or 3rd degree heart block
• Uncontrolled hypertension defined as systolic blood pressure ≥ 200 mmHg and/or diastolic blood pressure ≥ 110 mmHg at screening
• Hemoglobin (Hb) < 7.5 mg/dL at screening or within 3 months prior to screening
• Potassium < 3.0 mmol/L or > 5.5 mmol/L or severe electrolyte abnormality at screening that, in the opinion of the supervising physician or Investigator, makes stress testing unsafe
• Females who are pregnant or nursing
• Known intolerance to any of the study stress agents (dipyridamole, dobutamine) or study cardiac imaging agents (Optison, Cardiolite)
• Weight ≥ 350lbs
• Any physical or psychological condition that, in the opinion of the Investigator, may adversely affect the safety of the patient if enrolled in this trial.