Stress Induced Right Ventricular Uptake on Lexiscan Stress MPI

Phase 1: Retrospective data collection/analysis All Lexiscan and exercise MPI images on
patients performed for clinical indications in calendar year 2010 who had subsequent
coronary angiogram within 3 months after index MPI will be retrieved for review by two
experts. We will identify different types of RV uptake and RV overload during stress as well
as presence or absence of these changes on resting images. Analysis will include increased
RV uptake, enlargement, hypertrophy, thinning of RV and flattening of the interventricular
septum. Diagnostic performance (sensitivity, specificity and diagnostic accuracy) of the
identified pathological RV phenotypes in identifying severe and extensive disease will be
evaluated by comparison with contrary angiograms. Comparison of the set of parameters
identifying pathological RV changes, identifying normal and abnormal values of these novel
ancillary markers, as well as assessing their diagnostic accuracy in patients with suspected
and known CAD during vasodilator stress versus exercise stress MPI will be done.

Phase 2: Prospective data validation Patients referred for the Lexiscan stress MPI will be
followed prospectively after obtaining an informed consent. All comers after June 1 2012
will be included. Prediction of coronary artery disease will be performed by applying the
previously derived pathological RV criteria on the prospective stress MPIs.
2D-Echocardiogram will be performed for all the patients who do not have an Echocardiogram
performed for clinical indication within 1 month of their index Lexiscan stress MPI. We will
also include 100 patients referred for the exercise stress MPI who will serve as controls.

All patients will be prospectively followed up for a total of 12 months for the following
prognostic end points:

1. Hard cardiac events (cardiac death or MI);

2. Total (all-cause) mortality;

3. Cardiovascular hospitalization rate. Cardiac death (CD) will be defined as death
attributable to any cardiac cause (eg, lethal arrhythmia, myocardial infarction [MI],
or pump failure) as confirmed by review of death certificate and medical records.

Inclusion Criteria:

1. Retrospective population (approximately 300 charts to be reviewed)

- Patients with MPI and 2D Echocardiogram within one month of the stress testing
in calendar year 2010 at University Medical Center, Tucson AZ.

- 18 years or older.

2. Prospective population (approximately 350 subjects to be recruited)

- Patients scheduled for MPI at University Medical Center, Tucson AZ.

- 18 years to 89 years old

Exclusion Criteria (applied to both retrospective and prospective arms):

- patients with nondiagnostic or technically defective MPI

- incomplete clinical data

- severe valvular heart disease

- complex congenital heart disease

- life expectancy less than one year at the time of the index MPI

- unable to follow up (absence of permanent address)

- Known prisoners, pregnant women and cognitively impaired patients.