Stress Radionuclide Myocardial Perfusion Imaging Research Articles

Initial description of changes in wall motion parameters in normal subjects undergoing rest/regadenoson stress using a tagged MRI sequence

Background Changes in global and regional wall motion between rest and stress are important prognostic markers, uncommonly observed with vasodilator stress radionuclide myocardial perfusion imaging (MPI). Cardiac MRI (CMR) with tagging has the potential to more precisely quantify normal and abnormal ventricular wall motion responses. We herein report CMR findings in 5 very low-likelihood patients for CAD undergoing rest/regadenoson stress with tagging.

Hyperdynamic left ventricle on radionuclide myocardial perfusion imaging (RNMPI): A marker of diastolic dysfunction in patients presenting with dyspnea on exertion

BackgroundWe hypothesized that among patients presenting with dyspnea on exertion (DOE), those who were found to have hyperdynamic left ventricle (i.e. LVEF≥70%) on stress radionuclide myocardial perfusion imaging (RNMPI), are more likely to have features of diastolic dysfunction on transthoracic echocardiography. MethodsMedical records of 1892 consecutive patients who presented between February 2011 and September 2012 with the chief complaint of DOE and were referred to stress RNMPI were reviewed. Among these, patients who had no evidence of reversible ischemia and had hyperdynamic left ventricle on perfusion imaging, were selected and their recent echocardiograms were reviewed for evidence of diastolic dysfunction. Logistic regression analysis was used to develop an equation to predict diastolic dysfunction with the ejection fraction as the predictor. A two-way analysis of variance model was used to detect differential patterns of ejection fraction across diastolic dysfunction and gender. ResultsA hyperdynamic left ventricle identified on stress RNMPI was found to be a significant predictor of diastolic dysfunction on echocardiography in logistic regression analysis (odds ratio=1.24, 95% CI=1.13–1.35, p<0.0001). A hyperdynamic left ventricle on stress RNMPI has a specificity of 96.77% (CI 83.24–99.46%) and a positive predictor value of 97.83% (CI 88.43–99.64%) in identifying diastolic dysfunction. ConclusionIn patients presenting with DOE who have no evidence of reversible ischemia on radionuclide stress testing but have hyperdynamic left ventricle, a search should be made for alternate cardiac etiology for this complaint such as diastolic dysfunction and heart failure with preserved ejection fraction.

The origins and early years of the American Society of Nuclear Cardiology

In 1971 and 1973, Drs Strauss and Zaret published the seminal descriptions of stress radionuclide myocardial perfusion imaging and of ECG-gated blood pool imaging, marking the beginning of what we know now as nuclear cardiology. In the later years (1975-1980), radionuclide cardiac imaging emerged as a distinct entity within the field of nuclear medicine. The publication by Dr Gould on pharmacologic stress perfusion imaging was also pivotal for the development of this field. Of relevance for later developments, it was predominantly cardiologists who investigated and introduced the use of nuclear medicine techniques for clinical imaging of the heart. At the national meetings of the American College of Cardiology (ACC) and the American Heart Association (AHA), an increasing number of scientific sessions were devoted to clinical applications of radionuclide cardiac imaging. However, the daylong symposium on cardiovascular imaging at the annual meeting of the Society of Nuclear Medicine (SNM) became the most important annual educational and scientific event for those involved in nuclear cardiac imaging. The increasing interest in Nuclear Cardiology led to the formation of the Cardiovascular (CV) Council of the SNM on November 12, 1985. Dr Elias Botvinick was the founder and the first president, who was joined by a small core group of mainly cardiologists. Subsequent presidents were all prominent investigators in the field of nuclear cardiology, and many of them were cardiologists (Table 1). With 1,012 members, the CV Council became the most dynamic and largest council of the SNM. Thirty-six percent of the members were nuclear physicians, 32% cardiologists, 22% technologists, and 10% representatives of industry. Nevertheless, cardiologists were the predominant forces within the CV Council with regard to educational and research activities. After several years of very successful and wellattended cardiovascular imaging symposia, many cardiac imaging investigators felt that nuclear cardiology should expand as a field on its own and become more widely inclusive to those physicians who were becoming interested in this area of medicine. Early attempts to develop this concept within the SNM were not very successful. The leadership of the SNM exercised their official power to limit the operation of the CV Council as a mainly educational activity for its own nuclear medicine community and obviously had no desire to initiate a separate and potentially independent professional society within its own ranks. To many of the members of the CV Council, it became increasingly clear that a more effective and likely independent representation might be needed to advance the field. It was also recognized that such an effort should include clear guidelines for clinical training and practice that would lead to more consistent quality of nuclear cardiology services. The lack of such standards and the perception that there was wide variation in the field of nuclear cardiology practice was felt to significantly harm its credibility.

Rationale and design of a randomized controlled trial comparing stress myocardial perfusion imaging with coronary CT angiography as the initial imaging study for intermediate-risk patients admitted with chest pain

Noninvasive cardiac imaging plays an important role in the diagnosis and management of coronary artery disease (CAD). Prior studies have focused on the diagnostic performance of noninvasive modalities using angiographically significant stenoses as the reference standard. Recent trends in evidence-based medicine and increasing imaging utilization call for validation of diagnostic algorithms with well-designed, controlled trials with clinical outcome endpoints. To compare the performance of stress radionuclide myocardial perfusion imaging (MPI) and coronary computed tomography angiography (CTA) in terms of outcomes. We designed a single-center, randomized controlled trial that compares MPI and CTA as the initial modality for the evaluation of patients hospitalized for chest pain without known CAD or acute myocardial infarction. Patients with intermediate-risk characteristics and a clinical need for noninvasive imaging are included. The primary outcome measured is the incidence of conventional angiography not leading to subsequent coronary revascularization within 1 year. The study is powered to detect a reduction from 11% to 3% in catheterization not leading to an intervention with a sample size of 400. Secondary outcomes include procedural complications and posttest renal dysfunction (safety outcomes), major adverse cardiovascular events, length of hospital stay, subsequent hospitalizations and imaging, changes in medical management, and tolerability of the noninvasive test. The results of this trial will further our understanding of the relative appropriateness of CTA and MPI in evaluating intermediate-risk patients hospitalized with chest pain. It will also have implications for the design and probability of success of multicentered trials that are currently being planned.

Screening of asymptomatic patients with type 2 diabetes mellitus for silent coronary artery disease: Combined use of stress myocardial perfusion imaging and coronary calcium scoring

Diabetes mellitus and coronary artery disease constitute an ominous clinical combination. Rates of morbidity and mortality as a result of cardiovascular complications are high in patients with type 2 diabetes mellitus. Screening for silent coronary artery disease, to detect the disease in an early stage and to be able to initiate early appropriate treatment, has recently become an important focus of clinical investigation. Recent prospective studies have shown that the overall prevalence of silent coronary artery disease in truly asymptomatic individuals with diabetes is about 20% to 25%. It is of practical and clinical importance to explore ways to "enrich" the target screening population. In this editorial point of view the relative roles of stress radionuclide myocardial perfusion imaging and coronary calcium scoring are examined. The two methodologies appear to have complementary values for the screening of asymptomatic individuals with diabetes mellitus. A screening algorithm involving sequential use of coronary calcium scoring and subsequent stress radionuclide myocardial perfusion imaging is proposed.

The effect of systemic hypertension (HTN) on the accuracy of stress radionuclide myocardial perfusion imaging

Background: HTN is common in patients (pts) undergoing stress testing. The aim of our study is to evaluate the diagnostic accuracy of stress SPECT with Tc-99m sestamibi perfusion imaging for the diagnosis of CAD in a large series of pts with HTN. Methods: We reviewed the database records of 1010 consecutive pts who had undergone stress SPECT myocardial perfusion imaging (stress MIBI) and coronary angiography within 90 days. Pts with CABG, LBBB/IVCD, paced rhythm, non-ischemic cardiomyopathy and valvular disease were excluded. Similar group of 606 pts with a low (<5%) pre test likelihood of CAD who did not undergo cardiac catheterization was also studied in order to determine the normalcy rate. We assessed data globally and for individual territories (LAD and non-LAD). Results: 634 (81%) of the pts had HTN. Pts with HTN were older (63±12 vs 60±13 years, p=0.024), were more often female (56% vs 48%, p=0.082), and had more multivessel/left main CAD (60% vs 42% of normotensive pts, p=0.000). Of the LL pts 334 (55%) had HTN For pts who underwent catheterization, the presence of LVH on ECG did not significantly affect the accuracy, but for the LL pts global (81.8%) and all vascular territory (89.7%) normalcy was reduced further. HTN (n = 634) No HTN (n = 146) P Value Global Sensitivity 86.8% (433/499) 82.8% (77/93) NS Specificity 31.9% (43/135) 43.4% (23/53) NS All Vascular Territories Sensitivity 62.7% (519/828) 60.9% (92/151) NS Specificity 63.2% (278/440) 68.1% (96/141) NS Low Likelihood pts (n = 334) (n = 272) Global Normalcy 88.9% (297/334) 96.0% (261/272) 0.002 All Vascular Territories Normalcy 93.9% (627/668) 98.0% (533/544) 0.000 Conclusions: Although the sensitivity of the stress MIBI was similar between pts with and without HTN, there was a trend towards lower specificity in the HTN pts. The normalcy rate was significantly worse in HTN pts, particularly in those with LVH.

The prognostic value of ECG-gated SPECT imaging in patients undergoing stress Tc-99m sestamibi myocardial perfusion imaging

Background The ability of stress radionuclide myocardial perfusion imaging to predict adverse cardiac events is well accepted. As left ventricular systolic function has also been shown to be an important prognostic indicator, the objective of this study was to determine whether electrocardiography (ECG)–gated single photon emission computed tomography (SPECT) functional data add additional power. Methods and results In this study 3207 patients who underwent stress myocardial perfusion imaging with ECG gating, without early (≤60 days) revascularization, were studied. Subsequent nonfatal myocardial infarction and cardiac death were related to perfusion and ECG-gated SPECT ventricular function parameters. Cox proportional hazards regression analysis was used to evaluate the independent predictive value of these parameters, as well as their added utility over clinical and ECG parameters. Patients with abnormal perfusion images had an annual event rate of 5.1% compared with 1.6% for patients with normal images ( P < .001). An abnormal gated SPECT wall motion score was associated with an annual event rate of 6.1% compared with 1.6% for a normal score ( P < .001), and an abnormal left ventricular ejection fraction was associated with an event rate of 7.4% compared with 1.8% for normal patients ( P < .001). Abnormal ECG-gated SPECT results worsened outcome in both patients with normal perfusion images and those with abnormal perfusion images. Cardiac death was predicted by the number of territories with a perfusion defect and an abnormal ejection fraction, whereas myocardial infarction was predicted by the number of territories with a perfusion defect but not by ejection fraction. Conclusions Ventricular function data from ECG-gated SPECT add important prognostic value to data obtained from perfusion imaging alone in predicting adverse cardiac events.

Clinical application of rest thallium-201/Stress technetium-99m sestamibi dual isotope myocardial perfusion single-photon emission computed tomography.

Stress radionuclide myocardial perfusion imaging is a commonly used modality to evaluate patients with known or suspected coronary artery disease. The dual isotope rest thallium-201/stress technetium-99m sestamibi gated single-photon emission computed tomography protocol has gained increasing popularity for these applications. By combining the use of thallium-201, the optimal radioisotope for assessment of viability, with technetium-99m, a radionuclide agent that permits optimal image resolution and simultaneous assessment of viability information, maximization of clinical information can be achieved. Recent publications have demonstrated the efficacy of this imaging approach for both the identification of the presence of coronary artery disease and risk stratification.

Assessment of coronary artery disease in women

Stress radionuclide myocardial perfusion imaging and stress echocardiography are noninvasive imaging techniques with high diagnostic and prognostic utility. Previously, patient cohorts for studies using these methods have comprised predominantly men, but recent investigations have focused on women. Stress myocardial perfusion imaging is highly accurate for diagnosing coronary disease in women, particularly with newer techniques such as gated single-photon emission computed tomography, and has been shown to be a powerful prognostic predictor in both women and men. Comparable data for stress echocardiography are emerging. Older studies reported that for similar image findings fewer women than men were referred for invasive procedures, however, newer studies suggest an absence of such a gender bias. Further developments in attenuation correction for perfusion imaging and phase-contrast magnetic resonance imaging promise to enhance the utility of noninvasive imaging for both men and women.

Myocardial Perfusion Imaging (MPI), An Overview

The clinical utility of radiotracer study of heart in nuclear cardiology must always be considered in the of context of other cardiac diagnostic procedures, including ECG, Echo, ETT,CAG and cardiac enzymes or serum cardiac protein. So one should not be a hop cardiologist.Two modalities in Nuclear Cardiology: 1).Radionuclide Angiography (RNA) or Radionuclide Ventriculography. 2).Myocardial Perfusion Imaging (MPI).Radionuclide Angiography (RNA) or Radionuclide Ventriculography: This procedure is designed to provide measurement of LVEF in patient of coronary artery disease, valvular heart disease or cardiomyopathy. In our setting we determine EF from MPI, so Radionuclide Angiography routinely not do in many centre of world including NICVD, Dhaka.Myocardial Perfusion Imaging (MPI): MPI, more specifically myocardial perfusion single photon emission computed tomography (SPECT) is a nice tool for the noninvasive assessment of myocardial perfusion, ejection fraction, wall motion, and wall thickness.Why not perform cardiac catheterization and coronary angiography in all patients suspected of having coronary artery diseases?The contrast coronary angiogram displays the anatomic extent of epicardial coronary artery disease, the severity of luminal narrowing, and the number of diseased vessels. Stress radionuclide myocardial perfusion imaging, on the other hand, displays the downstream functional consequences of epicardial coronary artery disease in the myocardium. It also may visualize the regional effects of micro vascular endothelial dysfunction and impairment of regional coronary flow reserve. Application of MPI: The diagnosis of coronary artery disease remain common application of MPI ,but it is increasingly being used for the diagnosis of acute MI, risk stratification after infarction, and assessment of viable myocardium versus scar in patients in chronic coronary artery disease. Keywords: Myocardial Perfusion Imaging (MPI); Myocardial viability; Radiopharmaceutical DOI: 10.3329/cardio.v3i1.6428Cardiovasc. j. 2010; 3(1): 55-65