Sestamibi Perfusion Imaging Research Articles

Sex differences in mental stress-induced myocardial ischemia in young survivors of an acute myocardial infarction.

Emotional stress may disproportionally affect young women with ischemic heart disease. We sought to examine whether mental stress-induced myocardial ischemia (MSIMI), but not exercise-induced ischemia, is more common in young women with previous myocardial infarction (MI) than in men. We studied 98 post-MI patients (49 women and 49 men) aged 38 to 60 years. Women and men were matched for age, MI type, and months since MI. Patients underwent technetium-99m sestamibi perfusion imaging at rest, after mental stress, and after exercise/pharmacological stress. Perfusion defect scores were obtained with observer-independent software. A summed difference score (SDS), the difference between stress and rest scores, was used to quantify ischemia under both stress conditions. Women 50 years or younger, but not older women, showed a more adverse psychosocial profile than did age-matched men but did not differ for conventional risk factors and tended to have less angiographic coronary artery disease. Compared with age-matched men, women 50 years or younger exhibited a higher SDS with mental stress (3.1 versus 1.5, p = .029) and had twice the rate of MSIMI (SDS ≥ 3; 52% versus 25%), whereas ischemia with physical stress did not differ (36% versus 25%). In older patients, there were no sex differences in MSIMI. The higher prevalence of MSIMI in young women persisted when adjusting for sociodemographic and life-style factors, coronary artery disease severity, and depression. MSIMI post-MI is more common in women 50 years or younger compared with age-matched men. These sex differences are not observed in post-MI patients who are older than 50 years.

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.

Noninvasive identification of cardiac allograft vasculopathy with real-time myocardial contrast echocardiography: comparison with ivus, coronary angiography and 99mTC sestamibi perfusion imaging

Purpose: Cardiac allograft vasculopathy (CAV) remains a major long-term complication after heart transplantation (HTx) which is usually monitored by coronary angiography and intravascular ultrasound (IVUS). Myocardial contrast echocardiography (MCE) is a new, promising noninvasive technique to evaluate microvascular perfusion and to identify significant coronary stenosis. The aim of the study was to assess the prognostic value of stress MCE in comparison to coronary angiography including IVUS and stress 99mTC Sestamibi perfusion imaging.

Diagnosis of acute cardiac ischemia

A better understanding of coronary syndromes allow physicians to appreciate UAP and AMI as part of a continuum of ACI. ACI is a life-threatening condition whose identification can have major economic and therapeutic importance as far as threatening dysrhythmias and preventing or limiting myocardial infarction size. The identification of ACI continues to challenge the skill of even experienced clinicians, yet physicians continue (appropriately) to admit the overwhelming majority of patients with ACI; in the process, they admit many patients without acute ischemia [2], overestimating the likelihood of ischemia in low-risk patients because of magnified concern for this diagnosis for prognostic and therapeutic reasons. Studies of admitting practices from a decade ago have yielded useful clinical information but have shown that neither clinical symptoms nor the ECG could reliably distinguish most patients with ACI from those with other conditions. Most studies have evaluated the accuracy of various technologies for diagnosing ACI, yet only a few have evaluated the clinical impact of routine use. The prehospital 12-lead ECG has moderate sensitivity and specificity for the diagnosis of ACI. It has demonstrated a reduction of the mean time to thrombolysis by 33 minutes and short-term overall mortality in randomized trials. In the general ED setting, only the ACI-TIPI has demonstrated, in a large-scale multicenter clinical trial, a reduction in unnecessary hospitalizations without decreasing the rate of appropriate admission for patients with ACI. The Goldman chest pain protocol has good sensitivity for AMI but was not shown to result in any differences in hospitalization rate, length of stay, or estimated costs in the single clinical impact study performed. The protocol's applicability to patients with UAP has not been evaluated. Single measurement of biomarkers at presentation to the ED has poor sensitivity for AMI, although most biomarkers have high specificity. Serial measurements can greatly increase the sensitivity for AMI while maintaining their excellent specificity. Biomarkers cannot identify most patients with UAP. Finally, diagnostic technologies to evaluate ACI in selected populations, such as echocardiography, sestamibi perfusion imaging, and stress ECG, may have very good to excellent sensitivity; however, they have not been sufficiently studied.

Sestamibi perfusion imaging predicts wall motion recovery beyond TIMI grade 3 flow following primary stenting

Sestamibi perfusion imaging predicts wall motion recovery beyond TIMI grade 3 flow following primary stenting

Diagnosing acute cardiac ischemia in the emergency department: A systematic review of the accuracy and clinical effect of current technologies

Study Objective: Acute cardiac ischemia (ACI) encompasses the diagnoses of unstable angina pectoris and acute myocardial infarction (AMI). Accurate diagnosis and triage of patients with ACI in the emergency department should increase survival for these patients and reduce unnecessary hospital admissions. Methods: We conducted a systematic review of the English-language literature published between 1966 and December 1998 on the accuracy and clinical effect of diagnostic technologies for ACI. We evaluated prospective and retrospective studies of adult patients who presented to the ED with symptoms suggesting ACI. Outcomes were diagnostic performance (test sensitivity and specificity) and measures of clinical effect. Meta-analyses were performed when appropriate. A decision and cost-effectiveness analysis was conducted that investigated various diagnostic strategies used in the diagnosis of ACI in the ED. Results: We screened 6,667 abstracts, reviewed 407 full articles, and included 106 articles articles in the main analysis. Single measurements of biomarkers at presentation to the ED have low sensitivity for AMI, although they have high specificity. Serial measurements greatly increase the sensitivity for AMI while maintaining their excellent specificity. Diagnostic technologies to evaluate ACI in selected populations, such as electrocardiography, sestamibi perfusion imaging, and stress ECG, may have very good to excellent sensitivity; however, they have not been sufficiently studied. The Goldman Chest Pain Protocol has good sensitivity (about 90%) for AMI but has not been shown to result in any differences in hospitalization rate, length of stay, or estimated costs in the single clinical effect study performed. Its applicability to patients with unstable angina pectoris has not been evaluated. The use of an Acute Cardiac Ischemia-Time-Insensitive Predictive Instrument led to the appropriate triage of 97% of patients with ACI presenting to the ED and reduced unnecessary hospitalizations. Conclusion: Many of the current technologies remain underevaluated, especially regarding their clinical effect. The extent to which combinations of tests may provide better accuracy than any single test needs further study. [Lau J, Ioannidis JPA, Balk EM, Milch C, Terrin N, Chew PW, Salem D. Diagnosing acute cardiac ischemia in the emergency department: a systematic review of the accuracy and clinical effect of current technologies. Ann Emerg Med. May 2001;37:453-460.]

Prognostic implications of Tc-99m sestamibi viability imaging and subsequent therapeutic strategy in patients with chronic coronary artery disease and left ventricular dysfunction

OBJECTIVESThe aim of the study was to verify the prognostic implications of viability detection using baseline-nitrate sestamibi imaging in patients with left ventricular (LV) dysfunction due to chronic coronary artery disease (CAD) submitted to different therapeutic strategies.BACKGROUNDThe prognostic meaning of preserved viability in these patients is still debated. Sestamibi is increasingly used for myocardial perfusion scintigraphy and is being accepted also as viability tracer, but no data are available about the relationship between viability in sestamibi imaging, subsequent treatment, and patient’s outcome.METHODSFollow-up data were collected in 105 CAD patients with LV dysfunction who had undergone baseline-nitrate sestamibi perfusion imaging for viability assessment and had been later treated medically (group 1), or submitted to revascularization, which was either complete (group 2A) or incomplete (group 2B).RESULTSEighteen hard events (cardiac death or nonfatal myocardial infarction) were registered during the follow-up. A significantly worse event-free survival curve was observed in the patients of group 1 (p < 0.0002) and group 2B (p < 0.03) compared to those of group 2A. Using a Cox proportional hazard model, the most powerful prognostic predictors of events were the number of nonrevascularized asynergic segments with viability in sestamibi imaging (p < 0.003, risk ratio [RR] = 1.4), and the severity of CAD (p < 0.02, RR = 1.28).CONCLUSIONSViability detection in sestamibi imaging has important prognostic implications in CAD patients with LV dysfunction. Patients with preserved viability kept on medical therapy or submitted to incomplete revascularization represent high-risk groups.

Value of Acute Rest Sestamibi Perfusion Imaging for Evaluation of Patients Admitted to the Emergency Department With Chest Pain

Objectives. This study sought to determine the ability of early perfusion imaging using technetium-99m sestamibi to predict adverse cardiac outcomes in patients who present to the emergency department with possible cardiac ischemia and nondiagnostic electrocardiograms (ECGs).Background. Evaluation of patients presenting to the emergency department with possible acute coronary syndromes and nondiagnostic ECGs is problematic. Accurate risk stratification is necessary to prevent serious adverse outcomes. Initial results suggest that early perfusion imaging using technetium-99m sestamibi enables reliable risk stratification.Methods. Patients presenting to the emergency department with a low to moderate probability of acute coronary syndromes underwent rapid sestamibi injection with gated single-photon emission computed tomographic imaging. Studies showing perfusion defects with associated wall motion abnormalities were considered positive.Results. A total of 532 consecutive patients underwent serial myocardial marker analysis and rest perfusion imaging. Of these patients, perfusion imaging was positive in 171 (32%). Positive perfusion imaging was the only multivariate predictor of myocardial infarction (MI) (p < 0.0001, odds ratio [OR] 33, 95% confidence interval [CI] 7.7 to 141) and was the most important independent predictor of MI or revascularization (p < 0.0001, OR 14, 95% CI 7.3 to 25), followed by diabetes (p < 0.01, OR 2.8, 95% CI 1.5 to 5.1), typical angina (p = 0.01, OR 2.1, 95% CI 1.2 to 3.7) and male gender (p = 0.03, OR 1.9, 95% CI 1.1 to 3.5). The sensitivity of positive perfusion imaging for MI was 93% (95% CI 77% to 98%), and for MI or revascularization it was 81% (95% CI 71% to 88%), with negative predictive values of 99% (95% CI 98% to 100%) and 95% (95% CI 92% to 97%), respectively.Conclusions. Positive rest perfusion imaging accurately identified patients at high risk for adverse cardiac outcomes, whereas negative perfusion imaging identified a low risk patient group. Early perfusion imaging allows for rapid and accurate risk stratification of emergency department patients with possible cardiac ischemia and nondiagnostic ECGs.

Prospective Validation of a Composite End Point in Thrombolytic Trials of Acute Myocardial Infarction (TIMI 4 and 5)

Although the use of composite end points in clinical trials has increased in recent years, few data are available on the validity of such an approach. In the Thrombolysis In Myocardial Infarction (TIMI) 4 and 5 trials, we set out to validate prospectively the nonfatal components of the “unsatisfactory outcome” end point. This end point consisted of the in-hospital occurrence or observation of new-onset severe congestive heart failure/shock, left ventricular ejection fraction <40% (or <30% for patients with prior myocardial infarction), reinfarction, reocclusion by sestamibi perfusion imaging, TIMI flow grade <2 at 90 minutes or 18 to 36 hours, intracranial hemorrhage, major spontaneous hemorrhage, or anaphylaxis. Among 576 patients in TIMI 4 and 5 with 1-year follow-up, a nonfatal unsatisfactory outcome end point was reached in hospital in 45% of patients. Compared with patients without such an end point, patients with an end point had a relative risk of 1-year mortality of 2.5 (95% confidence interval 1.4 to 5.6, p = 0.001). For individual components, new-onset severe congestive heart failure/shock had a relative risk of 4.6 (p = 0.001), left ventricular ejection fraction <40% had a relative risk of 3.5 (p = 0.006), recurrent myocardial infarction had a relative risk of 2.2 (p = 0.047), and TIMI flow grade <2 at 90 minutes had a relative risk of 2.2 (p = 0.005). Our findings show that these nonfatal in-hospital end points and the composite end point are associated with an increased risk of 1-year mortality and as such are valid predictive survival markers for use in clinical trials.

Comparison of Tc-99m Sestamibi Perfusion Imaging and Echocardiography Using an Arbutamine Infusion for the Detection of Coronary Artery Disease

Arbutamine, a synthetic catecholamine, coupled with a closed-loop, computerized delivery system was evaluated in conjunction with technetium-99m sestamibi scintigraphy and echocardiography for the detection of coronary artery disease. Concordance between the imaging methods was 68%, with a similar sensitivity for coronary disease using echocardiography (78%) and technetium-99m sestamibi (76%), although more arbutamine-induced ischemia was noted with perfusion imaging.

Correlates of Unrecognized Acute Myocardial Infarction Detected Via Perfusion Imaging

Research using the electrocardiogram (ECG) indicates that about 1/3 of acute myocardial infarctions (AMIs) are unrecognized. To date, no studies of unrecognized AMIs have employed perfusion imaging, although it is more sensitive than the ECG and provides more information about infarct characteristics, such as size and location. In this study, 82 of 258 consecutive patients (31.8%) undergoing exercise testing with technetium-99m sestamibi perfusion imaging had fixed, nonartifactual perfusion defects, suggesting AMI. These patients were interviewed regarding their recognition of AMI; 27 patients (32.9%) had unrecognized AMI. Unrecognized AMI was significantly associated with (1) smaller infarcts, (2) infarcts not in the apical or septal regions, (3) diabetes mellitus, (4) lack of angina, (5) a negative family history for cardiac disease, and (6) being African-American. Many of these variables were significantly intercorrelated, and in multivariate analysis, unrecognized AMI remained significantly predicted by a smaller infarct and lack of angina. This study suggests that the incidence of unrecognized AMI detected via perfusion imaging on a clinic population is similar to that detected via electrocardiographic studies on community samples. This study also replicates prior findings of the medical history and demographic correlates of unrecognized AMI, and indicates that infarct size and location are also associated with unrecognized AMI.

Prognostic Significance of Systolic Blood Pressure Changes During Dobutamine-Atropine Stress Technetium-99m Sestamibi Perfusion Scintigraphy in Patients With Chest Pain and Known or Suspected Coronary Artery Disease

To investigate the prognostic value of dobutamine stress-induced changes in systolic blood pressure (BP) 418 patients (mean age 60 years, 238 men) with chest pain and known or suspected coronary artery disease, who underwent a dobutamine-atropine stress technetium-99m sestamibi myocardial perfusion scintigraphic study, were followed up for 25 ± 15 months. Blood pressure was measured by automatic sphygmomanometry every 3 minutes. A marked decrease and increase in systolic BP from rest to peak were defined as changes of ≥20 mm Hg, and ≥30 mm Hg, respectively. Worst outcome events were cardiac death (n = 30), nonfatal myocardial infarction (n = 17), and hospitalization for congestive heart failure (n = 8). A decrease in systolic BP (prevalence 16%) was associated with older age and higher baseline systolic BP. Fixed and reversible sestamibi perfusion defects and follow-up results were similar to patients without a systolic BP decrease. In contrast, an increase in systolic BP (prevalence 24%) was associated with younger age, lower baseline systolic BP, and with absence of a history of prior congestive heart failure or treatment with angiotensin-converting enzyme inhibitors. Furthermore, these patients had fewer fixed perfusion defects and tended to have fewer annual event rates (3.5% vs 7.5%, p <0.10). In a multivariate model, an increase in systolic BP was not an independent predictor for subsequent events. In conclusion, a dobutamine-induced decrease in systolic BP is not associated with fixed or reversible sestamibi defects or adverse prognosis. An increase in systolic BP, however, is associated with less fixed sestamibi defects and a tendency toward less annual event rates.During dobutamine-atropine stress technetium-99m sestamibi perfusion imaging in 418 patients, a decrease in systolic blood pressure (BP) ≥20 mm Hg was present in 16% of the patients and an increase in systolic BP ≥30 mm Hg was present in 24% of the patients. A decrease in systolic BP was not associated with fixed and reversible sestamibi perfusion defects or clinical outcome (cardiac death, nonfatal myocardial infarction, congestive heart failure); an increase in systolic BP, however, was associated with less fixed defects and a tendency toward better clinical outcome.

Prognostic value of systolic blood pressure modifications during dobutamine-atropine technetium-99m sestamibi perfusion imaging

Prognostic value of systolic blood pressure modifications during dobutamine-atropine technetium-99m sestamibi perfusion imaging

Comparative Diagnostic Accuracy of Tl-201 and Tc-99m Sestamibi SPECT Imaging (Perfusion and ECG-Gated SPECT) in Detecting Coronary Artery Disease in Women

Objectives. This prospective study was conducted in 115 women to directly compare the sensitivity and specificity of thallium-201 (Tl-201), technetium-99m (Tc-99m) sestamibi perfusion and Tc-99m sestamibi electrocardiographic (ECG)-gated single-photon emission computed tomographic (SPECT) studies for detection of coronary artery disease (CAD).Background. Data on the comparative diagnostic accuracy of Tl-201 and Tc-99m sestamibi perfusion imaging for the detection of CAD, specifically in women, are very limited.Methods. Eighty-five patients with suspected CAD, scheduled for coronary angiography, and 30 volunteers with a pretest likelihood of ≤5% for CAD were evaluated. Within 1 week, each patient underwent Tl-201 and Tc-99m sestamibi SPECT imaging procedures (both perfusion and gated SPECT imaging). Treadmill stress testing was used in 78 patients and dipyridamole in the remaining 37 patients. All images were interpreted by three observers in a blinded manner (consensus reading). Technetium-99m sestamibi SPECT studies were read without and then with ECG gating. Technetium-99m sestamibi gated SPECT studies were used to differentiate scar tissue from soft tissue attenuation artifact.Results. The overall sensitivities for detecting ≥50% and ≥70% stenoses were 75.0% and 84.3%, respectively, for Tl-201, and 71.9% and 80.4%, respectively, for Tc-99m sestamibi perfusion studies (p = 0.48). The specificity for lesions ≥50% was 61.9% for Tl-201 and 85.7% for Tc-99m sestamibi perfusion (p = 0.07), whereas for lesions ≥70% it was 58.8% for Tl-201 and 82.4% for Tc-99m sestamibi perfusion (p = 0.01). When the 34 patients with a normal coronary angiogram were added to the group of 30 normal volunteers, the “specificity” for lesions ≥70% was 67.2% for Tl-201, 84.4% for Tc-99m sestamibi SPECT perfusion (p = 0.02) and 92.2% for Tc-99m sestamibi gated SPECT (p = 0.0004).Conclusions. Both Tl-201 SPECT and Tc-99m sestamibi SPECT perfusion studies had a similar sensitivity for the detection of CAD in women. However, Tc-99m sestamibi SPECT perfusion imaging shows a significantly better specificity, which is further enhanced by the use of ECG gating.(J Am Coll Cardiol 1997;29:69–77)>

Effect of time to thrombolytic therapy on infarct size assessed by tomographic sestamibi perfusion imaging

After adjustment for infarct location, prior infarct, thrombolytio and dose of pofoxamer 188, time remained significant (p = 0.027). However, a 2 hr increase in time was associated with an increase in infarct size of only 1.1% of the LV, compared to an increase of 8.1% for prior infarction and 16.7°/o for anterior infarction. Conclusion: rime to initiation of thrombolytic therapy is a significant determinant of infarct size as assessed by tomographio sealamibi perfusion imaging in the CORE trial. The magnitude of its effect is small compared to prior infarction or infarct location.

Transmission imaging of large attenuators using a slant hole collimator on a three‐headed SPECT system

By combining conjugate views, truncation-free attenuation profiles of patients can be obtained by using slant hole collimators on three-headed SPECT systems. The alterations in reconstruction algorithms necessary for use with slant hole collimators and potential image artifacts are discussed. Based on an evaluation of the size of objects that can be imaged without truncation and the size of the overlap region in the conjugate views, a 15 degrees slant angle was determined to be optimal. Studies with a 30 degrees slant hole collimator verified the ability of slant hole transmission imaging to provide accurate, truncation-free attenuation maps of a 56 cm lateral width phantom. The center of rotation was determined to be dependent on the slant angle and radius of rotation of the slant collimator. These studies also demonstrated that the spatial resolution in the transaxial plane of the attenuation maps depends on radius of rotation of the slant hole collimator, but does not depend on the radius of rotation of an uncollimated transmission source. A multiline transmission source was investigated for use with estimating the attenuation map in Tc-99m labeled sestamibi perfusion imaging.