Triage of patients for attenuation-corrected stress-first Tc-99m SPECT MPI using a simplified clinical pre-test scoring model.

BACKGROUND: Stress-only Tc-99m SPECT MPI saves time and reduces radiation exposure while a normal study has a benign prognosis. However, no guidelines exist as to which patients should undergo stress-first MPI. The purpose of this study was to validate a previously published pre-test prediction scoring model and refine the stress-first triage process further if possible. METHODS: We retrospectively reviewed all patients who underwent an attenuation-corrected Tc-99m SPECT MPI over a 39-month period. Based on 17-segment model semi-quantitative scoring, a successful stress-first MPI was defined as a summed stress attenuation-corrected score ≤ 1. Based on results from multivariate analysis, the previously published prediction score (comprised eight clinical and demographic variables) was compared to triage based on coronary artery disease (CAD) status alone and with the addition of other highly associated variables. Logistic regression and Chi-squared analyses were used to determine the magnitude of variable effect and to compare model results. RESULTS: A total of 2,277 patients were included, and the prediction score successfully stratified patients into low-risk (91.1% successful stress-first), intermediate-risk (79.4%), and high-risk (50.7%) groups. Comparing the use of the prediction score to the use of a history of CAD as the only triage factor, 69.0% of patients would be accurately triaged using the prediction score with a cutoff of 7 (maximized sensitivity and specificity), while 78.6% were correctly triaged with CAD status alone (P < .0001). The addition of variables highly associated with a successful stress-first protocol (congestive heart failure [OR 3.4] and an abnormal resting ECG [OR 2.1]) to CAD status further enhanced triage accuracy to 81% (P < .0001). CONCLUSIONS: While the previously described prediction score effectively identifies patients who can successfully undergo stress-first MPI, it is cumbersome. Triaging based solely on CAD status and with the addition of other key variables is practical and provides improved predictive accuracy for successful stress-first MPI. Utilizing this simplified pre-test scoring model may allow for wider adoption of stress-first imaging protocols which have clear advantages over traditional rest-stress protocols.

An assessment of the safety, hemodynamic response, and diagnostic accuracy of commonly used vasodilator stressors in patients with severe aortic stenosis.

BACKGROUND: Increasing numbers of patients are undergoing transcatheter aortic valve replacement, which often involves assessment of coronary artery disease ischemic burden. The safety and diagnostic accuracy of vasodilator stress agents in patients with severe aortic stenosis (AS) undergoing SPECT myocardial perfusion imaging (MPI) has not been established. METHODS: Patients with severe AS (valve area <1 cm2) on echocardiography who underwent vasodilator stress SPECT MPI at two centers were identified. Patients with aortic valve intervention prior to MPI or who underwent concurrent exercise during stress testing were excluded. AS patients were matched to controls without AS based on age, gender, BMI, ejection fraction, and stress agent. Symptoms, serious adverse events, hemodynamic response, and correlation to invasive angiography were assessed. RESULTS: A total of 95 cases were identified with 45% undergoing regadenoson, 31% dipyridamole, and 24% adenosine stress. A significant change in systolic blood pressure (BP), cases vs controls, was observed with adenosine [-17.9 ± 20.1 vs -2.6 ± 24.9 P = .03)], with a trend toward significance with regadenoson [-16.8 ± 20.3 vs -9.4 ± 17.9 (P = .08)] and dipyridamole [-17.8 ± 20.6 vs -9.0 ± 12.1 (P = .05)]. The change in heart rate was significantly different only for adenosine [5.3 ± 16.8 vs 14.2 ± 10.8 (P = .04)]. Overall, 45% of cases vs 24% of controls (P = .004) had a >20 mmHg decrease in systolic BP. Age, BMI, and resting systolic BP were related to a >20 mmHg decrease in systolic BP on univariate analysis, although only higher resting systolic BP was a predictor on multivariate analysis. In 33 patients who underwent angiography, the sensitivity, specificity, and diagnostic accuracy of vasodilator stress MPI was 77%, 69%, and 73%, respectively. No serious adverse events occurred in the severe AS patients. CONCLUSION: Severe AS patients are more likely to have a hemodynamically significant decrease in systolic BP with vasodilator stress. There were no serious adverse events in this severe AS cohort with good diagnostic performance of MPI compared to angiography.

Multicenter evaluation of stress-first myocardial perfusion image triage by nuclear technologists and automated quantification.

BACKGROUND: A stress-first myocardial perfusion imaging (MPI) protocol saves time, is cost effective, and decreases radiation exposure. A limitation of this protocol is the requirement for physician review of the stress images to determine the need for rest images. This hurdle could be eliminated if an experienced technologist and/or automated computer quantification could make this determination. METHODS: Images from consecutive patients who were undergoing a stress-first MPI with attenuation correction at two tertiary care medical centers were prospectively reviewed independently by a technologist and cardiologist blinded to clinical and stress test data. Their decision on the need for rest imaging along with automated computer quantification of perfusion results was compared with the clinical reference standard of an assessment of perfusion images by a board-certified nuclear cardiologist that included clinical and stress test data. RESULTS: A total of 250 patients (mean age 61 years and 55% female) who underwent a stress-first MPI were studied. According to the clinical reference standard, 42 (16.8%) and 208 (83.2%) stress-first images were interpreted as "needing" and "not needing" rest images, respectively. The technologists correctly classified 229 (91.6%) stress-first images as either "needing" (n = 28) or "not needing" (n = 201) rest images. Their sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 66.7%, 96.6%, 80.0%, and 93.5%, respectively. An automated stress TPD score ≥1.2 was associated with optimal sensitivity and specificity and correctly classified 179 (71.6%) stress-first images as either "needing" (n = 31) or "not needing" (n = 148) rest images. Its sensitivity, specificity, PPV, and NPV were 73.8%, 71.2%, 34.1%, and 93.1%, respectively. In a model whereby the computer or technologist could correct for the other's incorrect classification, 242 (96.8%) stress-first images were correctly classified. The composite sensitivity, specificity, PPV, and NPV were 83.3%, 99.5%, 97.2%, and 96.7%, respectively. CONCLUSION: Technologists and automated quantification software had a high degree of agreement with the clinical reference standard for determining the need for rest images in a stress-first imaging protocol. Utilizing an experienced technologist and automated systems to screen stress-first images could expand the use of stress-first MPI to sites where the cardiologist is not immediately available for interpretation.

A Temporal Correlation Between Electrocardiogram and Computed Tomography in Acquired Postpneumonectomy Dextrocardia.

Herein, we describe a temporal correlation between the electrocardiographic changes and the chest computed tomographic findings in a 73-year-old woman who underwent a right pneumonectomy (RP) for lung adenocarcinoma.

Electrocardiographic changes in Emphysema.

Chronic obstructive lung disease (COPD), predominantly emphysema, causes several thoracic anatomical and hemodynamic changes which may cause changes in various electrocardiographic parameters. A 12-lead electrocardiogram (ECG), which is often a part of routine evaluation in most clinical settings, may serve as a useful screening modality for diagnosis of COPD or emphysema. Our current article aims to provide a comprehensive review of the electrocardiographic changes encountered in COPD/emphysema utilizing published PubMed and Medline literature database. Several important ECG changes are present in COPD/emphysema and may serve as a good diagnostic tool. Verticalization of P-vector, changes in QRS duration, pattern recognition of precordial R-wave progression and axial shifts can be considered some of the most valuable markers among other changes. In conclusion, 12-lead surface electrocardiogram can serve as a valuable tool for the diagnosis of COPD and/or emphysema. An appropriate knowledge of these ECG changes can not only help in the diagnosis but can also immensely help in an appropriate clinical management of these patients.

Coronary Atherosclerosis in Masters Athletes: Mechanisms and Implications for Cardiovascular Disease Risk.

PURPOSE OF REVIEW: This manuscript reviews the data on the mechanisms and significance of atherosclerotic cardiovascular disease (ASCVD) in masters athletes. It describes recent advances in understanding the biological pathway for the development and progression of ASCVD in athletes. It also reviews salient clinical trials, guidelines on managing ASCVD in masters athletes, and future research directions. RECENT FINDINGS: Recent data have produced controversy as to whether high levels of physical activity and endurance training can promote ASCVD. Longstanding, vigorous endurance exercise may increase the development of calcified and non-calcified coronary plaques. There are no clinical trials to inform clinicians on how to manage masters athletes with occult ASCVD. We provide a review of the data on ASCVD in older athletes, the risks and benefits of exercise in active individuals with ASCVD, and our approach to evaluating and managing these patients. Vigorous physical exertion transiently increases the risk of acute coronary syndrome (ACS) and sudden cardiac death in patients with ASCVD. New research has demonstrated increases in both calcified and non-calcified plaque in athletes, although the dominant plaque type is usually calcific. The mechanisms mediating this possible increase in atherosclerosis in active individuals is uncertain, as is the prognostic implications of the increased atherosclerosis. The predominance of calcified plaque may indicate that coronary plaques in athletes are less prone to rupture and to produce acute coronary events. Some guidelines offer recommendations on the management of non-athletic patients with elevated CAC but data on athletes is scarce. Until additional studies are available, we suggest that athletes with CAC values > 100 Agatston units be managed as if they have preclinical ASCVD. They should be informed of the symptoms of angina and ACS and the importance of prompt medical attention should such symptoms occur. Serum calcium and parathyroid hormones levels should be measured to exclude hyperparathyroidism. Patients should undergo symptom-limited maximal exercise stress testing and aggressive lipid treatment to achieve low-density lipoprotein cholesterol (LDL-C) values < 70 mg/dl.

Cardiac Screening in the Noncardiac Surgery Patient.

This article will address common cardiac conditions that require evaluation prior to noncardiac surgery, characterization of urgency and the risk associated with surgical procedures, calculation of preoperative risk assessment, indications for diagnostic testing to quantify cardiac risk, and perioperative strategies to minimize the risk of cardiac complications.