Stress Myocardial Perfusion Imaging Results Research Articles

Development and Piloting of a Patient-Centered Report Design for Stress Myocardial Perfusion Imaging Results

The management of coronary disease epitomizes the call to better engage patients in shared medical decision-making. Myocardial perfusion imaging (MPI) is the foundation of diagnosis, risk stratification, and subsequent therapy; however, MPI reports are currently interpretable by specialists but not patients. To design and test a patient-centered report for stress MPI test results. This qualitative study of outpatients who underwent an MPI stress test and clinicians used a mixed methods approach. Phase 1 (December 2018 to July 2019) used qualitative methods to design a patient-centered reporting tool, with 5 focus groups with 36 patients and 2 focus groups with 27 clinicians. Phase 2 (June to September 2019) consisted of pilot testing the reporting tool with feedback from a structured survey given to patients who received MPI reports before and after implementing the tool. Key themes around patient experiences with the current MPI reporting and their desire for a more useful report were identified, which led to a sample reporting tool after serial iterations with feedback. Differences in patient knowledge and engagement were assessed between patients before and after implementation of the new reporting tool using χ2 tests. From patient focus groups (26 patients; mean [SD] age, 66.3 [9.6] years, 9 [35%] women), 3 themes on the inadequacies of current MPI reporting were identified: (1) inconsistent delivery of results, (2) use of medical jargon, and (3) unclear posttest course. We identified 5 themes for a more patient-centered MPI report: desire for written information, discussion of the report with medical personnel, presentation of results in simple language with use of visual graphics, comparisons with normal results, and personalized risk estimates. In a pilot survey with 123 patients split into a pre-implementation group (69 patients; mean [SD] age, 68.2 [8.5] years; 27 [51%] women) and a postimplementation group (54 patients; mean [SD] age, 66.4 [8.7] years; 30 [56%] women), the patient-centered report led to more patients reading the entire report (45 [83%] vs 46 [67%]; P = .04) and improved knowledge of future risk of cardiac events (41 [76%] vs 20 [29%]; P < .001). There was also a numerically higher percentage of patients who found the report easy to read (45 [83%] vs 44 [68%]; P = .05) and understand (42 [78%] vs 43 [66%]; P = .16), although these results were not statistically significant. This study identified key elements of a patient-centered report design for stress MPI test results, which improved patient engagement and knowledge. These preliminary data support further implementation and study of a more patient-centered MPI report.

Abstract 363: Chest Pain Observation Unit: Does Post-Discharge Stress Testing Influence Physician Management Decisions?

Background: Chest pain (CP) accounts for approximately 6 million emergency visits per year in the United States. There is growing interest in strategies to effectively risk stratify pts for coronary artery disease (CAD) related events in a cost-effective manner. The use of chest pain observation units followed by early stress testing is frequently employed in these pts. However the utility of stress testing in this population is not well defined, and the effect of stress test results on subsequent management decisions is a topic of controversy. In the present study we examined the relationship of stress myocardial perfusion imaging (MPI) results to physician decisions regarding ccath in a single community teaching hospital. Methods: Retrospective study of 426 pts undergoing a chest pain observation strategy over a 24 month period. Pt eligible for the program had CP deemed possibly related to CAD but no diagnostic ECG changes and negative TnI measurements x2. All pts underwent outpt. stress MPI within 72 hours of discharge. Pts saw a cardiologist the day of stress MPI who reviewed the CP history, MPI results, and made decisions regarding further risk stratification. Demographic and medical history was collected from the pts chest pain observation unit record. Multivariate regression analysis was used to determine significant independent variables related to physician decisions regarding further risk stratification. Results: Of 426 pts who underwent outpt stress MPI, 71(16.7%) were positive for ischemia, and 16 (22.5% of +MPI) underwent cath with reperfusion performed in 8 (5PCI, 3 CABG, 11.3% of +MPI). Of the 355 pts with negative stress MPI, 5(1.4% of -MPI) underwent cath with reperfusion performed in 2 (2PCI, 0 CABG, 0.5% of -MPI). A MLR model suggested only stress MPI results were independently predictive of the use of ccath for risk stratification. Conclusion: Stress MPI was an important factor in physician decision-making regarding the need for ccath in pts managed in a chest pain observation unit. The rate of +MPI and subsequent use of ccath in our institution supports MPI as an appropriate step in risk stratification of low to moderate risk CP pts triaged through a CP observation unit.

Stress myocardial perfusion imaging for the evaluation and triage of chest pain in the emergency department: A randomized controlled trial

BackgroundPatients with acute coronary syndrome (ACS) often present atypically. In a randomized controlled trial, we studied whether adding stress myocardial perfusion imaging (SMPI) to an evaluation strategy for emergency department (ED) patients presenting with chest pain more effectively identifies patients with ACS. MethodsParticipants were randomized to standard ED chest pain protocol (clinical assessment) or standard protocol supplemented with SMPI results. During 6 hours of electrocardiogram (ECG) monitoring and serial cardiac markers (creatine kinase-MB isoenzyme, troponin), participants developing ST segment changes or elevated cardiac markers were admitted. Those with a negative observation period underwent SMPI (N = 1,004) or clinical assessment (N = 504) based on randomization, and admitted if their SMPI scan was abnormal or senior clinicians found a high or intermediate risk for ACS. ResultsSMPI participants had a significantly lower admission rate than clinical assessment participants (10.16% vs 18.45%), with no significant between-group differences in risk of cardiac events (CEs) after 30 days (0.40% vs 0.79%) or 1 year (0.70% vs 0.99%). ConclusionsWhen added to a standard triage strategy incorporating clinical evaluation, serial ECGs, and cardiac markers, SMPI improved clinical decision making for chest pain patients, significantly reducing the need for hospitalization without an increase in adverse CE rates at 30 days or 1 year.

Prediction of cardiovascular events in pre-dialysis chronic kidney disease patients with normal SPECT myocardial perfusion imaging

PurposePatients with normal stress myocardial perfusion imaging (MPI) results generally have an excellent prognosis with <1% cardiovascular events/year. Chronic kidney disease (CKD) is an established risk factor for cardiovascular events. However, the estimated glomerular filtration rate (eGFR) varies considerably among patients with CKD. We evaluated the prognostic value of eGFR for patients with CKD who did not undergo hemodialysis and had no evidence of coronary artery disease (CAD). Methods and subjectsPatients with CKD (n=108; 58 males; mean age: 74 years) with no CAD [no previous CAD and normal stress MPI results; summed stress score (SSS) <4] and with no history of hemodialysis were followed-up (mean duration: 24 months). CKD was defined by eGFR of <60ml/min/1.73m2 and/or persistent proteinuria. Cardiovascular events included cardiac death, non-fatal myocardial infarction, and unstable angina. ResultsCardiovascular events were observed in 8 patients with CKD (7%). The following were determined as significant predictors of these events: age (hazard ratio=1.14; p=0.019), hemoglobin levels (hazard ratio=0.69; p=0.021), eGFR (hazard ratio=0.94; p=0.008), SSS (hazard ratio=2.31; p=0.012), and summed difference score (hazard ratio=2.33; p=0.014). ConclusionsPatients with CKD and with no previous CAD and normal stress MPI results (SSS<4) may not exhibit an excellent cardiovascular prognosis. Further, a lower eGFR and stress MPI results may be the predictors of cardiovascular events. Thus, patients with a lower eGFR and/or normal stress MPI results (SSS<4) may require continuous follow-up.

Association between serum adipocyte fatty-acid binding protein concentrations, left ventricular function and myocardial perfusion abnormalities in patients with coronary artery disease

BackgroundAdipokines, including adipocyte fatty acid-binding protein (A-FABP), have been demonstrated to be involved in the pathogenesis of atherosclerosis. In the present study, we investigated the association of circulating A-FABP level with severity of myocardial perfusion abnormalities analyzed by Tl-201 dipyridamole single-photon emission computed tomography.MethodsA total of 170 patients with coronary artery disease (CAD) from cardiovascular clinics were enrolled in the study. Serum A-FABP levels, echocardiography, and stress myocardial perfusion imaging results were analyzed.ResultsCompared with the patients with mild CAD (summed stress score [SSS] ≤ 8), those with moderate to severe CAD (SSS > 8) had significantly higher A-FABP concentrations. However, the difference was attenuated in the subgroup of patients with heart failure. In the correlation analyses, A-FABP level was correlated with age, body mass index, waist circumference, levels of creatinine, fasting glucose, high-sensitivity C-reactive protein, N-terminal pro-brain natriuretic peptide, adiponectin, and several echocardiographic parameters, including left ventricular ejection fraction. Multivariate logistic regression analysis demonstrated that the A-FABP level was not only associated with higher SSS (odds ratio, 1.30; 95% confidence interval [CI], 1.01–1.69; P = 0.048), but also an independent risk factor for heart failure (odds ratio 2.71, 95% CI, 1.23–5.94; P = 0.013).ConclusionsSerum A-FABP levels not only were associated with myocardial perfusion abnormalities and left ventricular function, but also predicted the presence of heart failure in our patients with CAD.

Baseline stress myocardial perfusion imaging results and outcomes in patients with stable ischemic heart disease randomized to optimal medical therapy with or without percutaneous coronary intervention

The COURAGE trial reported similar clinical outcomes for patients with stable ischemic heart disease (SIHD) receiving optimal medical therapy (OMT) with or without percutaneous coronary intervention (PCI). The current post hoc substudy analysis examined the relationship between baseline stress myocardial ischemia and clinical outcomes based on randomized treatment assignment. A total of 1,381 randomized patients (OMT n = 699, PCI + OMT n = 682) underwent baseline stress myocardial perfusion single-photon emission computed tomographic imaging. Site investigators interpreted the extent of ischemia by the number of ischemic segments using a 6-segment myocardial model. Patients were divided into those with no to mild (<3 ischemic segments) and moderate to severe ischemia (≥ 3 ischemic segments). Cox proportional hazards models were calculated to assess time to the primary end point of death or myocardial infarction. At baseline, moderate to severe ischemia occurred in more than one-quarter of patients (n = 468), and the incidence was comparable in both treatment groups (P = .36). The primary end point, death or myocardial infarction, was similar in the OMT and PCI + OMT treatment groups for no to mild (18% and 19%, P = .92) and moderate to severe ischemia (19% and 22%, P = .53, interaction P value = .65). There was no gradient increase in events for the overall cohort with the extent of ischemia. From the COURAGE trial post hoc substudy, the extent of site-defined ischemia did not predict adverse events and did not alter treatment effectiveness. Currently, evidence supports equipoise as to whether the extent and severity of ischemia impact on therapeutic effectiveness.

Discordance Between the Morphological and Physiological Information of 64-Slice MSCT Coronary Angiography and Myocardial Perfusion Imaging in Patients With Intermediate to High Probability of Coronary Artery Disease

The aim of this study was to determine the relationship between the morphological and physiological information of coronary CT angiography (CCTA) and stress myocardial perfusion imaging (S-MPI) from the standpoint of risk stratification of patients with intermediate to high probability of coronary artery disease (CAD). In total, 51 patients underwent both CCTA and S-MPI as sequential examinations. In each patient, the severity of coronary plaque and stenosis (>50%) and the presence of myocardial perfusion abnormalities were assessed and the prognostic information from the CCTA and S-MPI results was compared. In 30 patients with normal S-MPI, 3 (10%) had only completely normal coronaries and another 3 (10%) had non-obstructive CAD as observed on CCTA. The remaining 24 patients (80%) with normal S-MPI and all 21 patients with abnormal S-MPI study had obstructive CAD. High-risk CAD (defined as obstructive left main trunk (LMT) lesion or 3-vessel disease) was seen in 10 (33%) of 30 patients with normal S-MPI, although it was less frequent than in the 14 (67%) of 21 patients with abnormal S-MPI. A normal S-MPI result can reflect a wide range of coronary atherosclerosis types and severities and, to some extent, involves severe coronary atherosclerosis such as LMT lesion and 3-vessel disease in patients with an intermediate to high probability of CAD.

Screening Stress Myocardial Perfusion Imaging and Eligibility for Liver Transplantation

Screening for coronary artery disease is common practice in the evaluation of liver transplantation candidates. However, it is unclear whether coronary screening influences transplantation eligibility. We sought to determine the association between screening stress myocardial perfusion imaging (MPI) results and the eligibility for liver transplantation. Within a retrospective cohort of liver transplantation candidates referred for screening stress MPI at a single institution from April 1998 to February 2004, we obtained the baseline characteristics, stress MPI results, transplantation eligibility, and transplantation denial criteria by chart review. Of 294 patients (39%) denied transplantation, the denial criteria were multifactorial for 91 (31%) of the candidates. Compared to candidates with low-risk stress MPI results, the odds of being denied transplantation were the same for candidates with intermediate-risk MPI results (odds ratio 0.93, 95% confidence interval 0.45 to 1.82) or high-risk MPI results (odds ratio 1.42, 95% confidence interval 0.54 to 3.73). This lack of association persisted in our analysis with additional stratification of stress MPI results into negative, positive-low-risk, positive-intermediate-risk, and positive-high-risk. In conclusion, the screening stress MPI results were not associated with liver transplantation eligibility. The large number of competing factors considered before transplantation listing and the low proportion of positive stress MPI results suggests that targeting screening to patients deemed otherwise acceptable for transplantation might increase the influence of stress MPI findings on transplantation eligibility.

Characteristics and outcome of octogenarian population referred for myocardial perfusion imaging: Comparison with non-octogenarian population with reference to gender

Octogenarian patients referred for stress myocardial perfusion imaging (MPI) differ from younger (non-octogenarian) patients in that they have lower prevalence of risk factors for CAD, but more frequent ischemic events and higher cardiac mortality. The purpose of this study was to investigate the efficacy of MPI in octogenarian men and women compared with that in the younger population, and to compare the prognostic value of stress MPI in both populations. We studied 162 consecutive patients aged > or = 80 years who were referred for stress MPI, and compared them with 253 consecutive patients aged < 80 years. Patients completed a questionnaire encompassing information about the existence of coronary risk factors, cardiac symptoms, coronary artery disease (CAD), myocardial infarction, coronary artery bypass graft, percutaneous transluminal coronary angioplasty, and results of stress MPI. The patients were followed up for cardiac mortality for a mean of 45 +/- 12 months. There were 61 women and 101 men (17% of all referrals) with a mean age of 83 +/- 3 (range 80-90). Parameters of octogenarian patients demonstrated a significantly lower prevalence of non-insulin-dependent diabetes mellitus (p < 0.02), hypercholestrolemia (p < 0.001), and smoking (p = 0.001) compared with non-octogenarian patients. The prevalence of known CAD was similar, but the prevalence of abnormal resting electrocardiogram, left ventricular (LV) dilatation, and stress-induced ischemia was significantly higher in octogenarians (p < 0.002). Cardiac mortality rate per year was 4.3% in octogenarians versus 1.3% in the younger population (p < 0.0001). The independent predictors according to MPI of cardiac death were LV dilatation and presence of ischemia in octogenarians, and severity of ischemia in non-octogenarians. The octogenarian population referred for stress single-photon emission computed tomography differed from the non-octogenarian group in that it had a lower prevalence of risk factors for CAD, but more frequent ischemic events and higher cardiac mortality; however, MPI variables predict adverse outcome in both populations.

Impact of diabetes on the risk stratification using stress single-photon emission computed tomography myocardial perfusion imaging in patients with symptoms suggestive of coronary artery disease.

Coronary artery disease can develop prematurely and is the leading cause of death among diabetics, making noninvasive risk stratification desirable. Patients with symptoms of coronary artery disease who were undergoing stress myocardial perfusion imaging (MPI) from 5 centers were prospectively followed (2.5+/-1.5 years) for the subsequent occurrence of cardiac death, myocardial infarction (MI), and revascularization. Stress MPI results were categorized as normal or abnormal (fixed or ischemic defects and 1, 2, or 3 vessel distribution). Of 4755 patients, 929 (19.5%) were diabetic. Patients with diabetes, despite an increased revascularization rate, had 80 cardiac events (8.6%; 39 deaths and 41 MIs) compared with 172 cardiac events (4.5%; 69 deaths and 103 MIs) in the nondiabetic cohort (P<0.0001). Abnormal stress MPI was an independent predictor of cardiac death and MI in both populations. Diabetics with ischemic defects had an increased number of cardiac events (P<0.001), with the highest MI rates (17.1%) observed with 3-vessel ischemia. Similarly, a multivessel fixed defect was associated with the highest rate of cardiac death (13.6%) among diabetics. The unadjusted cardiac survival rate was lower for diabetic patients (91% versus 97%, P<0.001), but it became comparable once adjusted for the pretest clinical risk and stress MPI results. In multivariable Cox analysis, both ischemic and fixed MPI defects independently predicted cardiac death alone or cardiac death/MI. Diabetic women had the worst outcome for any given extent of myocardial ischemia. In this large cohort of diabetics undergoing stress MPI, the presence and the extent of abnormal stress MPI independently predicted subsequent cardiac events. Using stress MPI in conjunction with clinical information can provide risk stratification of diabetic patients.

Comparison of pressure-derived fractional flow reserve with poststenotic coronary flow velocity reserve for prediction of stress myocardial perfusion imaging results

The physiologic importance of coronary stenoses can be assessed indirectly by stress myocardial perfusion imaging or directly by translesional pressure and flow measurements. The aims of this study were to compare myocardial fractional flow reserve (FFR myo), a recently proposed index of lesion significance derived from hyperemic translesional pressure gradients, with directly measured poststenotic flow velocity reserve for the prediction of myocardial perfusion stress imaging results in corresponding vascular beds. Poststenotic coronary flow velocity (0.018-inch guide wire) and translesional pressure gradients (2.7F fluid-filled catheter) were measured at baseline and after intracoronary adenosine (12 to 18 μg) in 70 arteries (diameter stenosis: mean 56% ± 15%, range 14% to 94% by quantitative angiography). Coronary flow reserve was calculated as the ratio of hyperemic to basal mean flow velocity. FFR myo was calculated during maximal hyperemia as equal to 1 — (hyperemic gradient [mean aortic pressure — 5]), where 5 is the assumed central venous pressure. Positive and negative predictive values and predictive accuracy for reversible stress myocardial perfusion abnormalities were computed. There was a significant correlation between pressure-derived FFR myo and distal coronary flow reserve ( r = 0.46; p < 0.0001). The strongest predictor of stress myocardial perfusion imaging results was the poststenotic coronary flow reserve (chi square = 33.2; p < 0.0001). The correlation between stress myocardial perfusion imaging and FFR myo was also significant (chi square = 8.3; p < 0.005). There was no correlation between stress myocardial perfusion imaging and percentage diameter stenosis (chi square = 2.9; p = 0.10) or minimal lumen diameter (chi square = 0.47; p = 0.73). A poststenotic coronary flow reserve of ≤2 had a positive predictive value of 89% for regionally abnormal myocardial perfusion imaging abnormalities, whereas the positive predictive values of FFR myo and angiographic percentage diameter stenosis were only 71% and 67% respectively. In conclusion, the predictive value of poststenotic coronary flow velocity reserve for stress-induced myocardial perfusion abnormalities exceeds that of the translesional FFR myo. These findings should be considered when applying these techniques for clinical decision making in the assessment of coronary stenosis severity.