Improved myocardial blood flow estimation with residual activity correction and motion correction in 18F-flurpiridaz PET myocardial perfusion imaging.

PURPOSE: We sought to evaluate the diagnostic performance for coronary artery disease (CAD) of myocardial blood flow (MBF) quantification with 18F-flurpiridaz PET using motion correction (MC) and residual activity correction (RAC). METHODS: In total, 231 patients undergoing same-day pharmacologic rest and stress 18F-flurpiridaz PET from Phase III Flurpiridaz trial (NCT01347710) were studied. Frame-by-frame MC was performed and RAC was accomplished by subtracting the rest residual counts from the dynamic stress polar maps. MBF and myocardial flow reserve (MFR) were derived with a two-compartment early kinetic model for the entire left ventricle (global), each coronary territory, and 17-segment. Global and minimal values of three territorial (minimal vessel) and segmental estimation (minimal segment) of stress MBF and MFR were evaluated in the prediction of CAD. MBF and MFR were evaluated with and without MC and RAC (1: no MC/no RAC, 2: no MC/RAC, 3: MC/RAC). RESULTS: The area-under the receiver operating characteristics curve (AUC [95% confidence interval]) of stress MBF with MC/RAC was higher for minimal segment (0.89 [0.85-0.94]) than for minimal vessel (0.86 [0.81-0.92], p = 0.03) or global estimation (0.81 [0.75-0.87], p < 0.0001). The AUC of MFR with MC/RAC was higher for minimal segment (0.87 [0.81-0.93]) than for minimal vessel (0.83 [0.76-0.90], p = 0.014) or global estimation (0.77 [0.69-0.84], p < 0.0001). The AUCs of minimal segment stress MBF and MFR with MC/RAC were higher compared to those with no MC/RAC (p < 0.001 for both) or no MC/no RAC (p < 0.0001 for both). CONCLUSIONS: Minimal segment MBF or MFR estimation with MC and RAC improves the diagnostic performance for obstructive CAD compared to global assessment.

Development, diagnostic performance, and interobserver agreement of a 18F-flurpiridaz PET automated perfusion quantitation system.

BACKGROUND: Computerized methodologies standardize the myocardial perfusion imaging (MPI) interpretation process. METHODS: To develop an automated relative perfusion quantitation approach for 18F-flurpiridaz, PET MPI studies from all phase III trial participants of 18F-flurpiridaz were divided into 3 groups. Count distributions were obtained in N = 40 normal patients undergoing pharmacological or exercise stress. Then, N = 90 additional studies were selected in a derivation group. Following receiver operating characteristic curve analysis, various standard deviations below the mean normal were used as cutoffs for significant CAD, and interobserver variability determined. Finally, diagnostic performance was compared between blinded visual readers and blinded derivations of automated relative quantitation in the remaining N = 548 validation patients. RESULTS: Both approaches yielded comparable accuracies for the detection of global CAD, reaching 71% and 72% by visual reads, and 72% and 68% by automated relative quantitation, when using CAD ≥ 70% or ≥ 50% stenosis for significance, respectively. Similar results were observed when analyzing individual coronary territories. In both pharmacological and exercise stress, automated relative quantitation demonstrated significantly more interobserver agreement than visual reads. CONCLUSIONS: Our automated method of 18F-flurpiridaz relative perfusion analysis provides a quantitative, objective, and highly reproducible assessment of PET MPI in normal and CAD subjects undergoing either pharmacological or exercise stress.

Assessing myocardial perfusion in suspected coronary artery disease: rationale and design of the second phase 3, open-label multi-center study of flurpiridaz (F-18) injection for positron emission tomography (PET) imaging.

BACKGROUND: Positron emission tomography (PET) myocardial perfusion imaging (MPI) with the novel radiopharmaceutical Fluorine-18 Flurpiridaz has been shown in Phase 1, 2, and first Phase 3 clinical studies to be safe and effective in diagnosing coronary artery disease (CAD). We describe the methodology of the second FDA-mandated phase 3 prospective, open-label, international, multi-center trial of F-18 Flurpiridaz PET MPI. METHODS: The primary study end point is to assess the diagnostic efficacy of F-18 Flurpiridaz PET MPI in the detection of significant CAD [≥ 50% by quantitative invasive coronary angiography (ICA)] in patients with suspected CAD. The secondary endpoints are to evaluate the diagnostic efficacy of F-18 Flurpiridaz PET MPI compared to Tc-99 m-labeled SPECT MPI in the detection of CAD in all patients and in the following subgroups: (1) females; (2) patients with body mass index ≥ 30 kg/m2; and (3) diabetic patients. This trial's design differs from the first phase 3 trial in that (1) comparison to SPECT is now a secondary end point; (2) patients with known CAD are excluded; and (3) both SPECT and PET MPI are performed before ICA. CONCLUSIONS: This second phase 3 study will provide additional evidence on the diagnostic efficacy of F-18 Flurpiridaz PET MPI in the detection of significant CAD. TRIAL REGISTRATION NUMBER: NCT03354273.

Dosimetry, biodistribution, and safety of flurpiridaz F 18 in healthy subjects undergoing rest and exercise or pharmacological stress PET myocardial perfusion imaging.

The objectives of this study were to evaluate radiation dosimetry, biodistribution, human safety, and tolerability of 18F-labeled flurpiridaz (Flurpiridaz) in normal subjects undergoing rest and separate-day exercise or adenosine pharmacological stress PET imaging. METHODS: 12 normal subjects were injected with 58.5 to 121 MBq (1.58 to 3.27 mCi) of Flurpiridaz intravenously at rest on Day 1 and 57 to 171 MBq (1.54 to 4.61 mCi) during stress on Day 2. Sequential whole-body imaging was performed for 5 hours. Blood samples were collected for up to 8 hours. RESULTS: The heart wall received the largest mean absorbed dose with both exercise and adenosine stresses. The mean effective dose was 0.054 rem/mCi (0.015 mSv/MBq) with exercise and 0.069 rem/mCi (0.019 mSv/MBq) with adenosine pharmacological stress. The maximum dose that may be administered without exceeding 1 rem (10 mSv) effective dose was 19 mCi (685 MBq) for exercise and 15 mCi (539 MBq) for adenosine pharmacological stress. There were no drug-related adverse events, and the tracer was well tolerated in all subjects. CONCLUSION: Based on radiation dosimetry, biodistribution, and safety observations, 18F-labeled flurpiridaz is found suitable for clinical PET myocardial perfusion imaging in conjunction with either exercise or pharmacological stress testing.

Flurpiridaz F-18 PET Myocardial Perfusion Imaging in Patients With Suspected Coronary Artery Disease.

BACKGROUND: Flurpiridaz F-18 (flurpiridaz) is a novel positron emission tomography (PET) myocardial perfusion imaging tracer. OBJECTIVES: The purpose of this study was to further assess the diagnostic efficacy and safety of flurpiridaz for the detection and evaluation of coronary artery disease (CAD) defined as ≥50% stenosis by quantitative invasive coronary angiography (ICA). METHODS: In this second phase 3 prospective multicenter clinical study, 730 patients with suspected CAD from 48 clinical sites in the United States, Canada, and Europe were enrolled. Patients underwent 1-day rest/stress flurpiridaz PET and 1- or 2-day rest-stress Tc-99m-labeled single photon emission computed tomography (SPECT) before ICA. PET and SPECT images were read by 3 experts blinded to clinical and ICA data. RESULTS: A total of 578 patients (age 63.7 ± 9.5 years) were evaluable; 32.5% were women, 52.3% had body mass index ≥30 kg/m2, and 33.6% had diabetes. Flurpiridaz PET met the efficacy endpoints of the study; its sensitivity and specificity were significantly higher than the prespecified threshold value by 2 of the 3 readers. The sensitivity of flurpiridaz PET was higher than SPECT (80.3% vs 68.7%; P = 0.0003) and its specificity was noninferior to SPECT (63.8% vs 61.7%; P = 0.0004). PET area under the receiver-operating characteristic curves were higher than SPECT in the overall population (0.80 vs 0.68; P < 0.001), women, and obese patients (P < 0.001 for both). Flurpiridaz PET was superior to SPECT (P < 0.001) for perfusion defect size/severity evaluation, image quality, diagnostic certainty, and radiation exposure. Flurpiridaz PET was safe and well tolerated. CONCLUSIONS: This second flurpiridaz PET myocardial perfusion imaging trial shows that flurpiridaz has utility as a new tracer for CAD detection, specifically in women and obese patients. (An International Study to Evaluate Diagnostic Efficacy of Flurpiridaz [18F] Injection PET MPI in the Detection of Coronary Artery Disease [CAD]; NCT03354273).

Properties of an ideal PET perfusion tracer: new PET tracer cases and data.

An ideal positron emission tomography (PET) tracer should be highly extractable by the myocardium and able to provide high-resolution images, should enable quantification of absolute myocardial blood flow (MBF), should be compatible with both pharmacologically induced and exercise-induced stress imaging, and should not require an on-site cyclotron. The PET radionuclides nitrogen-13 ammonia and oxygen-15 water require an on-site cyclotron. Rubidium-82 may be available locally due to the generator source, but greater utilization is limited because of its relatively low myocardial extraction fraction, long positron range, and generator cost. Flurpiridaz F 18, a novel PET tracer in development, has a high-extraction fraction, short positron range, and relatively long half-life (as compared to currently available tracers), and may be produced at regional cyclotrons. Results of early clinical trials suggest that both pharmacologically and exercise-induced stress PET imaging protocols can be completed more rapidly and with lower patient radiation exposure than with single-photon emission computerized tomography (SPECT) tracers. As compared to SPECT images in the same patients, flurpiridaz F 18 PET images showed better defect contrast. Flurpiridaz F 18 is a potentially promising tracer for assessment of myocardial perfusion, measurement of absolute MBF, calculation of coronary flow reserves, and assessment of cardiac function at the peak of the stress response.

18F-flurpiridaz positron emission tomography segmental and territory myocardial blood flow metrics: incremental value beyond perfusion for coronary artery disease categorization.

AIMS: We determined the feasibility and diagnostic performance of segmental 18F-flurpiridaz myocardial blood flow (MBF) measurement by positron emission tomography (PET) compared with the standard territory method, and assessed whether flow metrics provide incremental diagnostic value beyond relative perfusion quantitation (PQ). METHODS AND RESULTS: All evaluable pharmacological stress patients from the Phase III trial of 18F-flurpiridaz were included (n = 245) and blinded flow metrics obtained. For each coronary territory, the segmental flow metric was defined as the lowest 17-segment stress MBF (SMBF), myocardial flow reserve (MFR), or relative flow reserve (RFR) value. Diagnostic performances of segmental and territory MBF metrics were compared by receiver operating characteristic (ROC) areas under the curve (AUC). A multiple logistic model was used to evaluate whether flow metrics provided incremental diagnostic value beyond PQ alone. The diagnostic performances of segmental flow metrics were higher than their territory counterparts; SMBF AUC = 0.761 vs. 0.737; MFR AUC = 0.699 vs. 0.676; and RFR AUC = 0.716 vs. 0.635, respectively (P < 0.001 for all). Similar results were obtained for per-vessel coronary artery disease (CAD) ≥70% stenosis categorization and per-patient analyses. Combinatorial analyses revealed that only SMBF significantly improved the diagnostic performance of PQ in CAD ≥50% stenoses, with PQ AUC = 0.730, PQ + segmental SMBF AUC = 0.782 (P < 0.01), and PQ + territory SMBF AUC = 0.771 (P < 0.05). No flow metric improved diagnostic performance when combined with PQ in CAD ≥70% stenoses. CONCLUSION: Assessment of segmental MBF metrics with 18F-flurpiridaz is feasible and improves flow-based epicardial CAD detection. When combined with PQ, only SMBF provides additive diagnostic performance in moderate CAD.

Diagnostic Performance of PET Versus SPECT Myocardial Perfusion Imaging in Patients with Smaller Left Ventricles: A Substudy of the 18F-Flurpiridaz Phase III Clinical Trial.

The performance of SPECT myocardial perfusion imaging (MPI) may deteriorate in smaller hearts, primarily because of the lower resolution of conventional Anger cameras. 18F-flurpiridaz is a novel PET MPI agent with superior image and defect resolution. We sought to determine the diagnostic performance of 99mTc-labeled SPECT MPI compared with 18F-flurpiridaz PET MPI according to left ventricle (LV) size. Methods: We conducted a substudy of the phase III clinical trial of flurpiridaz (n = 750) and stratified diagnostic performance according to the median PET LV end-diastolic volume (LVEDV), with smaller LVs defined as having an LVEDV of less than 113 mL (n = 369) and larger LVs defined as having an LVEDV of at least 113 mL (n = 381). Images were interpreted by the majority rule of 3 independent masked readers. The reference standard was quantitative invasive angiography, with at least 50% stenosis in at least 1 coronary artery considered significant. Results: SPECT performance decreased significantly from an area under the curve (AUC) of 0.75 in larger LVs to 0.67 in smaller LVs (P = 0.03), whereas PET performance was similar in larger and smaller LVs (AUC, 0.79 vs. 0.77, P = 0.49). Accordingly, in smaller LVs, PET had a higher AUC (0.77) than the SPECT AUC (0.67) (P < 0.0001), a phenomenon driven by female patients (P < 0.0001). In smaller LVs, there was a degradation of SPECT sensitivity that was highly significant (P < 0.001), whereas there was no significant change in PET sensitivity according to LV size (P = 0.07). Overall, PET had significantly higher sensitivity than SPECT in both smaller LVs (67% vs. 43%, P < 0.001) and larger LVs (76% vs. 61%, P < 0.001). The specificities of PET and SPECT were similar in larger LVs (76% vs. 83%, P = 0.11). Although SPECT specificity improved in smaller compared with larger LVs (90% vs. 83%, P = 0.03), the PET specificity did not change with LV size (76% vs. 76%, P = 0.9). Conclusion: The diagnostic performance of 18F-flurpiridaz PET MPI is not affected by LV size and is superior to SPECT MPI in patients with smaller LVs, highlighting the importance of appropriate test selection in these patients.

Phantom evaluation of a cardiac SPECT/VCT system that uses a common set of solid-state detectors for both emission and transmission scans.

BACKGROUND: We developed a cardiac SPECT system (X-ACT) with low dose volume CT transmission-based attenuation correction (AC). Three solid-state detectors are configured to form a triple-head system for emission scans and reconfigured to form a 69-cm field-of-view detector arc for transmission scans. A near mono-energetic transmission line source is produced from the collimated fluorescence x-ray emitted from a lead target when the target is illuminated by a narrow polychromatic x-ray beam from an x-ray tube. Transmission scans can be completed in 1 min with insignificant patient dose (deep dose equivalent <5 muSv). METHODS: We used phantom studies to evaluate (1) the accuracy of the reconstructed attenuation maps, (2) the effect of AC on image uniformity, and (3) the effect of AC on defect contrast (DC). The phantoms we used included an ACR phantom, an anthropomorphic phantom with a uniform cardiac insert, and an anthropomorphic phantom with two defects in the cardiac insert. RESULTS: The reconstructed attenuation coefficient of water at 140 keV was .150 +/- .003/cm in the uniform region of the ACR phantom, .151 +/- .003/cm and .151 +/- .002/cm in the liver and cardiac regions of the anthropomorphic phantom. The ACR phantom images with AC showed correction of the bowing effect due to attenuation in the images without AC (NC). The 17-segment scores of the images of the uniform cardiac insert were 78.3 +/- 6.5 before and 87.9 +/- 3.3 after AC (average +/- standard deviation). The inferior-to-anterior wall ratio and the septal-to-lateral wall ratio were .99 and 1.16 before and 1.02 and 1.00 after AC. The DC of the two defects was .528 and .156 before and .628 and .173 after AC. CONCLUSION: The X-ACT system generated accurate attenuation maps with 1-minute transmission scans. AC improved image quality and uniformity over NC.

Phase-III Clinical Trial of Fluorine-18 Flurpiridaz Positron Emission Tomography for Evaluation of Coronary Artery Disease.

BACKGROUND: Fluorine-18 flurpiridaz is a novel positron emission tomography (PET) myocardial perfusion imaging tracer. OBJECTIVES: This study sought to assess the diagnostic efficacy of flurpiridaz PET versus technetium-99m-labeled single photon emission computed tomography SPECT for the detection and evaluation of coronary artery disease (CAD), defined as ≥50% stenosis by quantitative invasive coronary angiography (ICA). Flurpiridaz safety was also evaluated. METHODS: In this phase III prospective multicenter clinical study, 795 patients with known or suspected CAD from 72 clinical sites in the United States, Canada, and Finland were enrolled. A total of 755 patients were evaluable, and the mean age was 62.3 ± 9.5 years, 31% were women, 55% had body mass index ≥30 kg/m2, and 71% had pharmacological stress. Patients underwent 1-day rest-stress (pharmacological or exercise) flurpiridaz PET and 1- or 2-day rest-stress Tc-99m-labeled SPECT and ICA. Images were read by 3 experts blinded to clinical and ICA data. RESULTS: Sensitivity of flurpiridaz PET (for detection of ≥50% stenosis by ICA) was 71.9% (95% confidence interval [CI]: 67.0% to 76.3%), significantly (p < 0.001) higher than SPECT (53.7% [95% CI: 48.5% to 58.8%]), while specificity did not meet the prespecified noninferiority criterion (76.2% [95% CI: 71.8% to 80.1%] vs. 86.6% [95% CI: 83.2% to 89.8%]; p = NS). Receiver-operating characteristic curve analysis demonstrated superior discrimination of CAD by flurpiridaz PET versus SPECT in the overall population, in women, obese patients, and patients undergoing pharmacological stress testing (p < 0.001 for all). Flurpiridaz PET was superior to SPECT for defect size (p < 0.001), image quality (p < 0.001), diagnostic certainty (p < 0.001), and radiation exposure (6.1 ± 0.4 mSv vs. 13.4 ± 3.2 mSv; p < 0.001). Flurpiridaz PET was safe and well tolerated. CONCLUSIONS: Flurpiridaz PET myocardial perfusion imaging shows promise as a new tracer for CAD detection and assessment of women, obese patients, and patients undergoing pharmacological stress testing. A second phase III Food and Drug Administration trial is ongoing. (A Phase 3 Multi-center Study to Assess PET Imaging of Flurpiridaz F 18 Injection in Patients with CAD; NCT01347710).

Development and evaluation of a new fully automatic motion detection and correction technique in cardiac SPECT imaging.

BACKGROUND: In cardiac SPECT perfusion imaging, motion correction of the data is critical to the minimization of motion introduced artifacts in the reconstructed images. Software-based (data-driven) motion correction techniques are the most convenient and economical approaches to fulfill this purpose. However, the accuracy is significantly affected by how the data complexities, such as activity overlap, non-uniform tissue attenuation, and noise are handled. METHODS: We developed STASYS, a new, fully automatic technique, for motion detection and correction in cardiac SPECT. We evaluated the performance of STASYS by comparing its effectiveness of motion correcting patient studies with the current industry standard software (Cedars-Sinai MoCo) through blind readings by two readers independently. RESULTS: For 204 patient studies from multiple clinical sites, the first reader identified (1) 69 studies with medium to large axial motion, of which STASYS perfectly or significantly corrected 86.9% and MoCo 72.5%; and (2) 20 studies with medium to large lateral motion, of which STASYS perfectly or significantly corrected 80.0% and MoCo 60.0%. The second reader identified (1) 84 studies with medium to large axial motion, of which STASYS perfectly or significantly corrected 82.2% and MoCo 76.2%; and (2) 34 studies with medium to large lateral motion, of which STASYS perfectly or significantly corrected 58.9% and MoCo 50.0%. CONCLUSIONS: We developed a fully automatic software-based motion correction technique, STASYS, for cardiac SPECT. Clinical studies showed that STASYS was effective and corrected a larger percent of cardiac SPECT studies than the current industrial standard software.

Prospective multicenter evaluation of rapid, gated SPECT myocardial perfusion upright imaging.

BACKGROUND: A novel three-dimensional (3D) iterative image reconstruction method (3D-OSEM) has been developed that in phantom studies yielded comparable image quality at one half the imaging time. In this study, we compared standard (STD) and rapid (nSPEED) protocols for diagnostic quality of images and quantitation of end-diastolic volume (EDV), end-systolic volume (ESV), left ventricular ejection fraction (LVEF), and perfusion defect severity. METHODS: At 11 US community centers, 448 patients prospectively underwent rest-stress-gated SPECT imaging using Tc-99m-labeled agent. The difference in quality and diagnostic equivalence of STD and nSPEED images were blindly evaluated by three experts. Defect intensity was quantitated as %normal in the three coronary artery territories. RESULTS: Studies were abnormal in 40% of patients. In 98.7% of stress and 98% of rest images, the nSPEED image quality was identical to or better than the STD images. nSPEED images were diagnostically equivalent to the STD in 444/448 (99%) patients. A high correlation was observed between nSPEED and STD studies for measurement of EDV (Y = 0.957X, R (2) = 0.99), ESV (Y = 0.962X, R (2) = 0.99), and LVEF (Y = 1.005X, R (2) = 0.96). STD and nSPEED studies were not significantly different (P = ns) for quantitative perfusion defect severity. CONCLUSION: Rapid, gated rest-stress myocardial perfusion upright SPECT imaging may be achieved without compromising perfusion and function information.

Value of electrocardiographically gated single-photon emission computed tomographic myocardial perfusion scintigraphy in a cohort of symptomatic postmenopausal women.

The aim of this study is to prospectively evaluate the clinical value of electrocardiographically gated single-photon emission computed tomographic myocardial perfusion scintigraphy (MPS) imaging in a cohort of postmenopausal women with symptoms suggestive of ischemic heart disease. Forty-six postmenopausal women with no history of coronary artery disease (CAD), but with typical or atypical angina and >or=1 risk factor for CAD, were enrolled and underwent both coronary angiography and technetium-99m sestamibi MPS with exercise (n = 36) or pharmacologic stress (n = 10). All women were followed up for 5.0 +/- 3 years for the occurrence of hospitalization for acute coronary syndrome, myocardial infarction, and/or new-onset or worsening angina. CAD prevalence (>or=50% diameter stenosis) was 62% (26 of 42 patients). Fifteen patients (36%) had 1-vessel disease, 7 (17%) had 2-vessel disease, and 4 (10%) had 3-vessel disease. Diagnostic sensitivity and specificity of the exercise electrocardiogram were 67% and 69%, respectively. By comparison, sensitivity of MPS was 88% and specificity was 87.5% (p <0.0001). Cox survival analysis showed 3- and 5-year cumulative event-free survival rates of 97% and 94% for patients with normal MPS results compared with 60% and 48% for those with abnormal MPS findings (p <0.001). In conclusion, results of this study indicate high diagnostic and prognostic accuracy for MPS in symptomatic postmenopausal women.

Ethnic differences in the prognostic value of stress technetium-99m tetrofosmin gated single-photon emission computed tomography myocardial perfusion imaging.

OBJECTIVES: This study was designed to evaluate the differential prognostic value of gated single-photon emission computed tomographic imaging (SPECT) imaging in an ethnically diverse multicenter registry. BACKGROUND: Ethnic minority patient populations have reportedly higher coronary heart disease mortality with greater comorbidity and a clustering of risk factors at a significantly younger age when compared with Caucasian, non-Hispanic patients. Despite our increasingly diverse population, the predictive accuracy of cardiac imaging in ethnic minority patients is ill-defined. METHODS: A total of 7,849 patients were prospectively enrolled in a registry of patients undergoing exercise (44%) or pharmacologic stress (56%) technetium-99m tetrofosmin SPECT. Scans were scored using a 20-segment myocardial model with a 5-point severity index. Multivariable Cox proportional hazards models were employed to assess time to death or myocardial infarction. RESULTS: A total of 1,993 African-American, 464 Hispanic, and 5,258 Caucasian non-Hispanic patients underwent SPECT imaging. African-American and Hispanic patients more often had a history of stroke, peripheral arterial disease, angina, heart failure, diabetes, hypertension, and smoking at a younger age. Moderate or severely abnormal SPECT scans were noted in 21%, 17%, and 13% of African-American, Hispanic, and Caucasian non-Hispanic patients, respectively (p < 0.0001). Cardiovascular death rates were highest for ethnic minority patients (p < 0.0001). Annual rates of ischemic heart disease death ranged from 0.2% to 3.0% for Caucasian non-Hispanic and 0.8% to 6.5% for African-American patients with low-risk to severely abnormal SPECT scans (p < 0.0001). For post-stress ejection fraction <45%, annualized risk-adjusted death rates were 2.7% for Caucasian non-Hispanic patients versus 8.0% and 14.0% for African-American and Hispanic patients (p < 0.0001). CONCLUSIONS: The current results from a large observational registry reveal that exercise and pharmacologic stress SPECT effectively predicts major cardiovascular events in a large cohort of African-American and Hispanic patients evaluated for suspected myocardial ischemia. These results provide further evidence that ethnic minority patient populations have a worsening outcome related to cardiovascular disease.