Search

Background: Transient ischemic dilation of the left ventricle (LV) during stress echocardiography indicates extensive myocardial ischemia. It remains unclear whether the change of LV end‐systolic volume (ESV) or end‐diastolic volume (EDV) better correlated with significant coronary artery disease (CAD). Meanwhile, the clinical significance of the extent of the volumetric change post‐stress has not been investigated. Methods: One hundred and five individuals (62 ± 12 years and 75% men) who underwent coronary angiography following exercise treadmill echocardiography were enrolled retrospectively. An additional 30 age‐ and sex‐matched healthy subjects were included for comparison. LV dilation was defined as any increase in LV volume from rest to peak exercise. Patients who had at least two coronary arteries with significant stenosis were considered as having multi‐vessel CAD. Results: Thirty‐four patients had ESV dilation during exercise echocardiography. On the contrary, ESV decreased at peak exercise in all healthy subjects. Forty‐one patients had multi‐vessel CAD, and its prevalence was higher in patients with ESV dilation (65% vs 27%, p = 0.001). The extent of ESV increase correlated with CAD severity. ESV dilation is associated with multi‐vessel CAD (Odds ratio [OR] 5.02, 95% confidence interval [CI] 2.09 – 12.07, p < 0.001). After adjustment for EDV increase, clinical, electrocardiographic, and echocardiographic variables, the association remained significant (adjusted OR 5.57, 95% CI 1.37‐22.64; p = 0.02). Conclusions: ESV dilation independently correlated with multi‐vessel CAD, whereas EDV dilation did not. The amount of ESV increase correlated with the severity of CAD. Our findings provide a rationale for incorporating volume measurements into stress echocardiography practice. [ABSTRACT FROM AUTHOR]

Objective: To determine the significance of transient ischemic dilatation (TID) in patients with normal perfusion on adenosine stress/rest.Methods: We analyzed 430 consecutive patients with normal perfusion on 2-day adenosine stress/rest 99mTc-sestamibi. A group of 70 patients with Framingham 10-year coronary heart disease risk < 10% was used to derive abnormal TID thresholds (derivation group). The significance of TID at these thresholds was validated in the remaining 360 patients (validation group) followed for cardiac events for 31.2 ± 9.7 (mean ± SD) months.Results: Transient ischemic dilatation in the derivation group was 1.05 ± 0.13. Three definitions of an abnormal TID were used: > mean + 2SD (TID ≥ 1.32), > mean + 1SD (TID ≥ 1.19) and a TID in the group's highest quartile (TID ≥ 1.15). Of the 360 validation group patients, 12 (3.3%), 48 (13.3%) and 70 (19.4%) had TID ≥ 1.32, 1.19 and 1.15, respectively. Age, gender, family history of coronary artery disease (CAD), known CAD, smoking, hypertension, diabetes, dyslipidemia, rest LVEF, post-stress LVEF, ΔLVEF, ≥ 5% or 10% decrease in LVEF did not predict TID ≥ 1.32. However, TID ≥ 1.19 was predicted by rest LVEF and ≥ 5% decrease in LVEF (P = 0.04 and 0.02, respectively) and TID ≥ 1.15 was predicted by ≥ 5% decrease in LVEF (P = 0.02). Cardiac event-free survivals were similar in patients with a TID ≥ and < 1.32 (P = 0.68), ≥ and < 1.19 (P = 0.40) and ≥ and < 1.15 (P = 0.79).Conclusions: Transient ischemic dilatation does not confer adverse prognosis in patients with normal perfusion on adenosine stress/rest 99mTc-sestamibi irrespective of the threshold used for its definition. [ABSTRACT FROM AUTHOR]

PURPOSE: To further investigate the clinical significance of transient ischemic dilation (TID) on myocardial perfusion imaging (MPI) by analyzing the effect of anisodamine hydrobromide (a drug that can effectively ameliorate microcirculation) on the patients with isolated TID and the findings of previous literatures. METHODS: Total 107 patients with isolated TID (TID value≥1.11) were randomly divided into group A (n = 36; intravenous administration of anisodamine hydrobromide), group N (n = 36; intravenous administration of isosorbide dinitrate), and group C (n = 35; intravenous administration of normal saline). MPI and treadmill exercise test (TET) were performed again after 14-day course of intervention. Pre- and post-intervention frequencies of symptom were recorded. RESULTS: In group A, after intervention of anisodamine hydrobromide, the summed stress score (SSS) and TID value on MPI significantly decreased than those before intervention (P < 0.001), the durations of exercise (DEs) and metabolic equivalents (METs) in TET notably ascended (P < 0.001), as well as the symptom remarkably improved. In group N and group C, there were no significant differences in SSS, TID value, DEs, METs, and frequencies of symptom between pre- and post-intervention (P > 0.05). No significant improvement of symptoms in group N before and after treatment. CONCLUSIONS: TID with perfusion defect may usually predict a possibility of severe and extensive coronary artery disease (CAD). An isolated TID should be considered as a likelihood of coronary microvascular dysfunction (CMD). TET and coronary CT angiography (cCTA) are extremely helpful for the antidiastole on CAD and CMD. The administration of anisodamine hydrobromide might be an optional treatment for the patients with isolated TID. [ABSTRACT FROM AUTHOR]

Transient ischemic dilation (TID), a marker of severe coronary artery disease (CAD), is the post-stress to rest left ventricular (LV) volume ratio quantified using non ECG gated single photon emission computerized tomography (SPECT). Although prone positioning causes physiological reduction of LV volume in normal subjects, we hypothesize this may not occur in TID with underlying severe CAD as cardiac hemodynamics worsen when prone. We aim to evaluate the utility of the non ECG gated supine to prone LV volume ratio (SPLVr) for identifying severe CAD. Retrospective data analysis from 130 patients with TID ratio ≥ 1.21 and both post-stress supine and prone images. SPLVr had a significant negative correlation with summed stress (r =  - 0.221, p = 0.011) and rest (r =  - 0.292, p = 0.001) scores. Of the 129 cases with follow-up invasive or computed tomography coronary angiography, 52 (40.3%) had severe CAD (left main ≥ 50% stenosis, 3-vessel with ≥ 70% stenosis or 2-vessel with proximal left anterior descending ≥ 70% stenosis). Mean SPLVr was significantly lower in severe CAD cases (1.05 ± 0.14 vs 1.12 ± 0.17, p = 0.012). SPLVr predicted severe CAD on univariate [OR 0.12 (95% CI 0.00-0.35) p = 0.01] but not in multivariate analysis. SPLVr is a novel marker that negatively correlates with extent of perfusion abnormalities and is lower amongst TID patients with severe CAD. Larger studies are needed to assess if SPLVr can reliably identify underlying severe CAD amongst TID cases. [ABSTRACT FROM AUTHOR]

Single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) has attained widespread clinical acceptance as a standard of care for patients with known or suspected coronary artery disease (CAD). A significant contribution to this success has been the use of computer techniques to provide objective quantitative assessment in the standardization of the interpretation of these studies. Software platforms have been developed as a pipeline to provide the quantitative algorithms researched, developed and validated to be clinically useful so diagnosticians everywhere can benefit from these tools. The goal of this CME article (PART 1) is to describe the many quantitative tools that are clinically established and more importantly how clinicians should use them routinely in the interpretation, clinical management and therapy guidance of patients with CAD. [ABSTRACT FROM AUTHOR]

Gated myocardial perfusion imaging (gMPI) is an established tool for the diagnosis and risk stratification of patients with coronary artery disease (CAD) providing a variety of parameters regarding to perfusion and function of left ventricle (LV). Transient ischemic dilation (TID) is one of them. The presence of TID has been shown as a marker of severe and extensive CAD. The aim of this study was to correlate scintigraphic and angiographic findings of patients with positive TID on their gMPI scans. Methods: Stress-rest gMPI was performed for 27 patients with suspected CAD. TID was equal or higher than 1.03 (TID≥1.03) in all patients. All patients had invasive coronary angiography results during 3 months before or after their SPECT studies. Ejection fraction (EF), end-diastolic and end-systolic volumes (EDV, ESV), TID were calculated. We correlated angiographic results with scintigraphic findings of the patients with positive TID. Results: We couldn't find statistical significant difference in functional parameters of the left ventricle between the groups of patients with normal or near normal coronary angiograms and with abnormal angiograms. Conclusions: TID should be considered a high risk marker in clinical management of patients with suspected or known CAD. But it can also be positive in normal coronary angiograms of conditions such as hypertensive heart disease and hypertrophic cardiomyopathy. Therefore, TID should be correlated with other perfusion and functional parameters of LV to reach the final diagnosis. If it is the only finding, it is reasonable to be cautious while interpreting gMPI. [ABSTRACT FROM AUTHOR]

Aim: Transient ischemic dilation (TID) is a marker of severe coronary artery disease (CAD). We aimed to assess the incremental value of TID in a cohort of patients with known significant CAD who had recurrence of symptoms after revascularization.Methods: We identified in our databases 104 patients who had recent coronary revascularization and recurrence of symptoms. 62 patients had PCI (75 arteries) and 42 patients had CABG (104 arteries). All had follow-up stress SPECT MPI and repeat coronary angiography. Myocardial perfusion findings of ischemia and TID were correlated with presence of significant obstructive CAD (>70% stenosis).Results: Follow-up stress Tc-99m Sestamibi SPECT MPI revealed inducible ischemia in 38 patients (36.5%) and TID > 1.20 in 49 patients (47%). Subsequent coronary angiography showed significant obstructive CAD in 44 patients (42%). The sensitivity for detecting obstructive CAD was 61% for SPECT MPI alone, but increased significantly to 93% by the addition of TID as a diagnostic criterion (P < 0.0001).Conclusions: In this selected patient cohort with prior coronary revascularization, TID is an important marker of obstructive CAD and has incremental value over SPECT MPI alone. [ABSTRACT FROM AUTHOR]

Introduction: Gated myocardial perfusion SPECT has diagnostic and prognostic values in coronary artery disease (CAD). We tried to determine prognostic values of the left ventricular perfusion & functional indices as well as transient left ventricular dilation (TID) derived from gated myocardial perfusion SPECT. Methods: 1820 patients who underwent gated myocardial perfusion SPECT (Gated SPECT) were studied. The summed stress score (SSS), summed rest score (SRS) and summed difference score (SDS) were calculated. Cardiac events considered as nonfatal myocardial infarction, cardiac death, Coronary Care Unit admission and revascularization. Mean follow-up period after Gated SPECT was 23±10 months. Results: 1599 patients didn't have any events, while from remaining 221, six patients had an acute MI, 90 patients had CCU admission, 42 patients underwent revascularization and 84 patients died. There was statistically significant difference in the cardiac events based on age, sex, SSS, SRS, SDS, TPD, TID, left ventricular volumes and LVEF. Multivariable Cox regression analysis showed the most and independent predictors of cardiac events are age (P=0.001), SSS (P=0.01) and history of coronary angiography (CA) (P=0.01). History of CA had a greater than 4.4 fold increased incidence of a cardiac event. With increase in SSS for 1 score, 1.4 times and with increase one year in age 1.4 fold increase in future cardiac event were seen. Conclusion: There was a strong association between future cardiac events and clinical history, SSS, SRS, SDS, TPD, TID, left ventricular volumes and LVEF. The most and independent predictors were age, SSS and history of CA. [ABSTRACT FROM AUTHOR]

Single isotope 99mTc single-photon emission computed tomography-myocardial perfusion imaging (SPECT-MPI) is the most commonly used protocol for nuclear stress testing. Transient ischemic dilation of the left ventricle (TID) has been considered a specific marker of severe coronary artery disease (CAD). Recent publications have questioned the clinical utility of TID, specifically with regadenoson as a stressor and 4DM-SPECT software for TID analysis. These findings have not been demonstrated using other imaging packages. The goal of our study was to establish the TID threshold in the identification of Multi-vessel CAD using Quantitative Perfusion SPECT (QPS) software. Included in this study are 190 patients that had undergone regadenoson-stress, same day, single-isotope 99mTc MPI and had a coronary angiography within a designated 3-month period. QPS (Cedars-Sinai, LA, CA) automated image analysis software was used to calculate TID ratios which were compared across different CAD categories. Coronary angiograms were reviewed to identify both obstructive and nonobstructive CAD. The mean TID for patients with nonobstructive CAD (n = 91) was 1.02 ± 0.11, and the threshold for TID was 1.24. A receiver operating characteristic curve showed that TID had a poor discriminatory capacity to identify MVD (area under the curve 0.58) with a sensitivity of 3% and a specificity of 97%. In our study with regadenoson MPI in a predominantly African-American population, TID was found to be a poor predictor of MVD using QPS software. The reason is unclear but possibly related to the significant decline in the prevalence of severe CAD in the area where our study took place. [ABSTRACT FROM AUTHOR]

Background: Transient ischemic dilation (TID) of the left ventricle seen on myocardial perfusion imaging (MPI) is sometimes used as a marker of severe coronary artery disease. The prognostic value of TID obtained using regadenoson, a selective adenosine A2A receptor agonist, as a stress agent for MPI has not been studied.Methods: TID ratio was measured using an automated software program on consecutive patients with normal and abnormal perfusion pattern on regadenoson MPI at a single institution. An abnormal TID was defined as greater than 1.33. The primary outcome was a composite of cardiac death, non-fatal myocardial infarction (MI), and late coronary revascularization (CR, >90 days after MPI).Results: The study population consisted of 887 patients (62 ± 12 years, 66% male, 48% diabetes, 46% prior CR, 75% with abnormal perfusion pattern, left ventricular ejection fraction-LVEF 55 ± 6%). An abnormal TID was present in 51 (6%) patients. Baseline characteristics were not different based on the presence or absence of TID. Early CR (≤90 days) was performed in 11 (22%) patients with vs 92 (11%) patients without TID (P = .04). During a mean follow-up of 29 ± 19 months, the primary outcome occurred in 271 (31%) patients (22% cardiac death, 6% MI, 9% late CR). TID was associated with increased risk of the primary outcome (log-rank P = .017), an association largely driven by late CR. In a Cox proportional model adjusted for multiple variables including perfusion defect size (PDS) and LVEF, the hazard ratio for TID was 1.92 (95% CI 1.20-3.08, P = .007). In the subset of patients with normal perfusion pattern, there was no association between TID and outcomes.Conclusions: TID on regadenoson MPI carries important prognostic information that is independent from PDS and LVEF, but this association is restricted to patients with abnormal perfusion on imaging. [ABSTRACT FROM AUTHOR]

Myocardial perfusion imaging (MPI) is an established diagnostic test that provides useful prognostic data in patients with known or suspected coronary artery disease. In more than half of the patients referred for stress testing, vasodilator stress is used in lieu of exercise. Unlike exercise, vasodilator stress does not provide information on exercise and functional capacity, heart rate recovery, and chronotropy, and ECG changes are less frequent. These non-perfusion data provide important prognostic and patient management information. Further, event rates in patients undergoing vasodilator MPI are higher than in those undergoing exercise MPI and even in those with normal images probably due to higher pretest risk. However, there are a number of non-perfusion variables that are obtained during vasodilator stress testing, which have prognostic relevance but their use has not been well emphasized. The purpose of this review is to summarize the prognostic values of these non-perfusion data obtained during vasodilator MPI. [ABSTRACT FROM AUTHOR]

Introduction: The main purpose of this study was to compare transient ischemic dilation (TID) ratios in SPECT-low dose CT and SPECT Myocardial Perfusion Imaging (MPI) by application of different quantitative programs and quantify the possible shift in the upper normal limits of TID ratio in the SPECT-CT MPI. Methods: 149 Patients with low pre-test probability for coronary artery disease (CAD), based upon Diamond and Forrester method entered the study. Each patient underwent both attenuation correction (AC) SPECT-CT MPI and non attenuation correction (NAC) SPECT MPI (two day Tc-99m sestamibi stress-rest protocol). Normalcy rates were also calculated and compared. The comparison was based on both visual interpretation and quantitative analysis. Results: In the low pre-test probability group visual interpretations lead to a statistically significant improvement in normalcy rate in the SPECT-CT acquisition compared to the SPECT MPI. Regardless of the stress type and software programs used, no significant difference was noted in the upper normal limits of the TID ratios between the AC and NAC acquisitions. Conclusion: The study showed superiority of SPECT-CT MPI to SPECT MPI in terms of normalcy rate. We also propose new upper normal limits of TID ratios for different sets of acquisition-gender-stress modality-software programs. [ABSTRACT FROM AUTHOR]

Vasodilator first-pass stress cardiac magnetic resonance perfusion imaging [stress cardiac magnetic resonance (CMR)] is a reliable, noninvasive method for evaluating myocardial ischemia; however, it does not routinely evaluate metrics such as wall-motion abnormality (WMA) and transient ischemic dilation (TID). Using the new selective A adenosine receptor agonist regadenoson, we tested a novel protocol for assessing perfusion defects, WMA, and TID in a single stress CMR session. We evaluated 29 consecutive patients who presented for clinically indicated regadenoson stress CMR. Immediately before and after the regadenoson stress perfusion sequence, we obtained baseline and post-stress cine images in the short-axis orientation to detect worsening or newly developed WMAs. This approach also allowed evaluation of TID. Delayed-enhancement imaging was performed in the standard orientations. All patients tolerated the procedure well. Thirteen patients (45 %) had perfusion abnormalities, and four patients developed TID. Seven patients had WMAs, and three of them also had TID. Patients with TID ± WMAs had multivessel disease documented by coronary angiography. By using regadenoson to assess myocardial ischemia during stress CMR, perfusion defects, WMAs, and TID can be evaluated in a single imaging session. To our knowledge, we are the first to describe this novel approach in a vasodilator stress CMR study. [ABSTRACT FROM AUTHOR]

Introduction: Coronary artery disease (CAD) is a leading cause of death in developed countries. Non-invasive functional imaging modalities are currently recommended as initial diagnostic tests in patients with an intermediate-high pretest probability of CAD. Single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) creates images of regional myocardial tracer uptake, reflecting relative myocardial blood flow. However, there are other non-perfusion predictors of CAD, such as transient ischemic dilatation (TID) and reduced post-stress left ventricle ejection fraction (LVEF). Available data regarding these parameters is controversial. The aim of our study was to evaluate the incidence of significant CAD in patients with non-perfusion high-risk markers of ischemia despite a normal SPECT-MPI., Methods: Single-center, observational, retrospective, and longitudinal study. Inclusion criteria were age ≥18 years, normal SPECT-MPI, and availability of gated study for LVEF and volume analysis. Exclusion criteria were any known cardiomyopathy or congenital heart disease and known CAD. Non-perfusion high-risk markers: LVEF reduction ≥5% on post-stress images; TID (defined as a stress/rest left ventricle volume ratio ≥ 1.15), including end-systolic, end-diastolic, and mean volumes. The primary endpoint was the identification of significant CAD (stenosis >70% on an epicardial coronary artery or >50% on the left main artery) on invasive coronary angiography., Results: A total of 197 patients met the inclusion criteria. Mean age was 64 ± 12.6 years and 59.4% (n = 117) of patients were male. Overall, 26% of patients had LVEF reduction ≥5% on stress study; 24.9% had a stress/rest end-systolic volume ratio ≥ 1.15; 7.1% had a stress/rest mean volume ratio ≥ 1.15; 7.1% had a stress/rest end-diastolic volume ratio ≥ 1.15. Time-to-primary endpoint was significantly lower in patients with LVEF reduction ≥5% on stress study (67.99 (95% CI 60.49-75.49) vs. 77.56 months (95% CI 75.14-79.99); p = 0.003) and in patients with stress/rest end-systolic volume ratio ≥ 1.15 (68.39 (95% CI 60.69-76.10) vs. 77.31 months (95% ICCI 74.68-79.76); p = 0.013)., Conclusion: In patients with normal perfusion on SPECT-MPI, the incidence of significant CAD was significantly higher in those with LVEF reduction ≥ 5% on stress study and in those with a stress/rest end-systolic volume ratio ≥ 1.15, during a follow-up period of five years., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2022, Medeiros et al.)

Background: Transient ischemic dilation (TID) of the left ventricle in myocardial perfusion SPECT (MPS) has been shown to be a clinically useful marker of severe coronary artery disease (CAD). However, TID has not been evaluated for 99mTc-sestamibi rest/stress protocols (Mibi-Mibi). We aimed to develop normal limits and evaluate diagnostic power of TID ratio for Mibi-Mibi scans. Methods: TID ratios were automatically derived from static rest/stress MPS (TID) and gated rest/stress MPS from the end-diastolic phase (TID) in 547 patients who underwent Mibi-Mibi scans [215 patients with correlating coronary angiography and 332 patients with low likelihood (LLk) of CAD]. Scans were classified as severe (≥70% stenosis in proximal left anterior descending (pLAD) artery or left main (LM), or ≥90% in ≥2 vessels), mild to moderate (≥90% stenosis in 1 vessel or ≥70%-90% in ≥1 vessel except pLAD or LM), and normal (<70% stenosis or LLk group). Another classification based on the angiographic Duke prognostic CAD index (DI) was also applied: DI ≥ 50, 30 ≤ DI < 50 and DI < 30 or LLk group. Results: The upper normal limits were 1.19 for TID and 1.23 for TID as established in 259 LLk patients. Both ratios increased with disease severity ( P < .0001). Incidence of abnormal TID increased from 2% in normal patients to >36% in patients with severe CAD. Similarly, when DI was used to classify disease severity, the average ratios showed significant increasing trend with DI increase ( P < .003); incidence of abnormal TID also increased with increasing DI. The incidence of abnormal TID in the group with high perfusion scores significantly increased compared to the group with low perfusion scores (stress total perfusion deficit, TPD < 3%) ( P < .0001). The sensitivity for detecting severe CAD improved for TID when added to mild to moderate perfusion abnormality (3% ≤ TPD < 10%): 71% vs 64%, P < .05; and trended to improve for TID/TID: 69% vs 64%, P = .08, while the accuracy remained consistent if abnormal TID was considered as a marker in addition to stress TPD. Similar results were obtained when DI was used for the definition of severe CAD (sensitivity: 76% vs 66%, P < .05 when TID was combined with stress TPD). Conclusion: TID ratios obtained from gated or ungated Mibi-Mibi MPS and are useful markers of severe CAD. [ABSTRACT FROM AUTHOR]

Background: Transient ischemic dilation (TID) in the setting of an abnormal SPECT radionuclide myocardial perfusion imaging (MPI) study is considered a marker of severe and extensive coronary artery disease (CAD). However, the clinical significance of TID and its association with CAD in patients with an otherwise normal MPI study is unclear. Methods: From a database of patients who underwent MPI over a 9-year period, 96 without known cardiac history who had normal image perfusion patterns, and who underwent coronary angiography within 6 months, were identified. TID quantitative values were derived. To adjust for varying stress and image protocols, a TID index based on published threshold values was derived for each patient, with >1 considered as TID. We examined the relationship of TID to the presence/extent of CAD, and to a CAD prognostic index. TID was also correlated with patient survival. To address referral bias, survival in a separate cohort of 3,691 patients with a normal perfusion MPI who did not undergo angiography in the 6-month interval was correlated with the presence and severity of TID. Results: For 28 (29.2%) patients with normal MPI perfusion patterns but with TID, there was no increased incidence of CAD, multivessel or left main disease, or a higher prognostic index compared with no TID. In addition, there was no increased mortality associated with TID in both the angiography cohort and in the patients who did not undergo immediate angiography. Conclusions: TID in patients with an otherwise normal SPECT MPI study does not increase the likelihood of CAD, its extent or severity, and is not associated with worsened patient survival. [ABSTRACT FROM AUTHOR]

Background: Although transient left ventricular (LV) dilation is a well-known marker for extensive coronary artery disease (CAD), few studies performed quantitative analysis of LV function of post adenosine triphosphate (ATP) stress and at rest to detect extensive CAD. Methods: One hundred nineteen patients with suspected CAD underwent post-stress and resting gated single-photon emission computed tomography (SPECT). Myocardial perfusion was assessed with a 20-segment model, and the changes in LV volume and function with ATP were analyzed. In addition, the stress-induced volume ratio (SIVR), defined as stress-to-rest ratios (end-systolic volume × 5 + end-diastolic volume), was calculated. All the patients underwent coronary angiography within 3 months of gated SPECT. Results: In the 62 patients with multi-vessel CAD, the summed stress score (SSS) (16.6 ± 8.7 vs 11.5 ± 9.1; P < .002), summed difference score (SDS) (9.6 ± 5.8 vs 3.9 ± 4.2; P < .0001), the post-stress increase in end-diastolic volume (EDV) (7.7 ± 7.9 vs 2.2 ± 5.3 mL; P < .0001), the post-stress increase in end-systolic volume (ESV) (9.4 ± 6.0 vs 2.7 ± 4.0 mL; P < .0001), and the (SIVR) (1.21 ± 0.14 vs 1.06 ± 0.10; P < .0001) were greater than in the 57 patients with insignificant or single-vessel CAD, whereas the post-stress increase in ejection fraction (EF) was less (−6.0 ± 4.9 vs −2.0 ± 4.4%; P < .0001). In the detection of multi-vessel CAD, an SSS of ≥14 and an SDS of ≥9 showed sensitivities of 57% and 52%, respectively, and specificities of 63% and 88%, respectively, while increase in EDV of ≥6 mL, increase in ESV of ≥6 mL, decrease in EF of ≥5% after stress, and SIVR of ≥1.13 demonstrated sensitivities of 60%, 81%, 60%, and 74% and specificities of 74%, 77%, 77%, and 79%, respectively. The multivariate discriminant analysis revealed that the combination of post-stress increase in ESV and the SDS best identified multi-vessel CAD, with 81% sensitivity and 77% specificity (χ = 63.6), whereas the SDS alone showed 52% sensitivity and 88% specificity (χ = 22.4). Conclusions: The addition of 'post-ATP stress' and 'at rest' LV functional analysis using gated SPECT to conventional perfusion analysis helps to better identify patients with multi-vessel CAD. [ABSTRACT FROM AUTHOR]

Background: Diabetes and left ventricular hypertrophy (LVH) can cause coronary flow reserve abnormalities in the absence of coronary artery disease (CAD). We sought to evaluate the impact of LVH and diabetes on the relationship between ischemia, severe CAD, and transient ischemic dilation (TID) on adenosine myocardial perfusion imaging (MPI). Methods and Results: We prospectively recruited 157 patients referred for routine single-day adenosine technetium 99m MPI. LVH was assessed by use of transthoracic echocardiography. A ratio of 1.19 or greater on MPI defined TID in men and 1.31 or greater in women. Summed difference scores were determined by use of a 17-segment 5-point scoring system. TID was present in 22 of 157 patients (14%), diabetes in 54 of 157 (34%), and LVH in 42 of 157 (27%). By multivariate logistic regression, LVH, ischemia (summed difference score >2), and diabetes were independently predictive of TID. The incidence of TID was stratified by the presence or absence of diabetes and/or LVH in those with ischemia on MPI (8/8 [100%] vs 0/11 [0%], P < .002) or severe CAD on angiography (5/7 [71%] vs 0/8 [0%], P < .01). All those with TID (22/22 [100%]) had either diabetes or LVH (or both). Conclusion: Although this study confirms the association between TID and both ischemia and severe CAD, all patients with TID had diabetes, LVH, or frequently, both, suggesting that the pathophysiology of these disease processes may play an integral role in the manifestation of TID on adenosine MPI. [Copyright &y& Elsevier]

Transient ischemic left ventricular dilation (TID) is a marker of severe and extensive coronary artery disease as well as an increased risk of adverse outcomes. The patients with more severe and extensive ischemia, multivessel-type of perfusion abnormality as well as patients with left anterior descending artery (LAD) territory perfusion abnormality have more probability of having TID. Evaluation of TID may be purely visual, or based on calculation of TID ratio between stress and rest images. Cutoff values for an abnormal TED ratio vary widely throughout the literature and may be related to different factors like patient populations and imaging protocols. On the other hand, several other causes of TED in the absence of significant epicardial stenoses have been reported. These include severe hypertension with myocardial hypertrophy; hypertrophic cardiomyopathy; and dilated cardiomyopathy. [ABSTRACT FROM AUTHOR]

Background: A hypertensive response to exercise (HRE) is associated with false-positive stress echocardiograms and myocardial perfusion single photon emission computed tomography (myocardial perfusion imaging [MPI]) defects even in the absence of coronary artery disease (CAD). Transient ischemic dilation (TID) of the left ventricle on stress MPI is a marker of severe CAD and future cardiac events. This study evaluated the association between an HRE and TID.Methods and Results: Blinded quantitative TID assessment was performed in 125 patients who had an HRE and a summed stress score (SSS) of less than 4, as well as 125 control patients with an SSS of less than 4 and without an HRE matched for age, gender, and resting systolic blood pressure. Cardiac comorbidities, pretest Framingham risk, and exercise results were recorded. TID was defined as a stress-to-rest volume ratio of 1.22 or greater. An HRE was associated with a high prevalence of TID and significantly more TID than no HRE (25.6% vs 11.2%; odds ratio, 3.00 [95% confidence interval, 1.41-6.38]). TID was more prevalent even in subgroups with a low pretest probability CAD, including those without diabetes mellitus or angina. On conditional logistic regression analysis, an HRE was found to be independently associated with TID after consideration of other clinical and exercise MPI variables (odds ratio, 2.72 [95% confidence interval, 1.01-7.31]).Conclusion: An HRE is associated with a high prevalence of TID in patients without other significant perfusion defects, possibly as a result of global subendocardial ischemia induced by the HRE. [ABSTRACT FROM AUTHOR]

Background: The definition of an abnormal transient ischemic dilation (TID) ratio may be different according to stress type, type of isotope, and imaging protocols. The aim of this study was to derive the normal threshold and assessment of the TID ratio via 2-day dipyridamole stress/rest technetium 99m sestamibi myocardial perfusion single photon emission computed tomography (MPS).Methods and Results: We performed 2-day dipyridamole stress/rest Tc-99m sestamibi MPS in 665 patients. The TID ratio was calculated automatically with the Emory Cardiac Toolbox. The upper limit of normal (1.19) for the TID ratio was derived from 131 patients with a low (<5%) likelihood of coronary artery disease as mean + 2 SDs. Patients with complete or partial reversible defects or multivessel-type or left anterior descending artery (LAD) territory perfusion abnormalities had higher TID ratios than the other patients. These patients had a higher frequency of an abnormal TID ratio (>1.19) as well. Binary logistic regression analysis showed that ischemia and LAD territory perfusion abnormality were independent predictors of an abnormal TID ratio.Conclusion: The threshold for an abnormal TID ratio via 2-day post-dipyridamole stress/rest Tc-99m sestamibi MPS was greater than 1.19. By use of this protocol, TID is not uncommon and it is related to a greater amount of ischemic burden as well as multivessel-type or LAD territory perfusion abnormality. [ABSTRACT FROM AUTHOR]

Background: Although transient left ventricular (LV) dilation is a well-known marker for extensive coronary artery disease (CAD), few studies have performed quantitative analysis of LV function after stress and at rest to detect extensive CAD. Methods and Results: Poststress and resting gated single photon emission computed tomography (SPECT) was performed in 175 patients with suspected CAD. All of the patients underwent coronary angiography within 3 months of gated SPECT. In the 83 patients with multivessel CAD, the summed difference score was greater (9.2 ± 7.0 vs 3.3 ± 4.0, P < .0001), the poststress increase in end-systolic volume (ESV) was larger (7.0 ± 8.0 mL vs −0.8 ± 4.7 mL, P < .0001), and the poststress increase in ejection fraction (EF) was less (−4.7% ± 5.4% vs −0.4% ± 4.5%, P < .0001) than in the 92 patients with insignificant or single-vessel CAD. In the detection of multivessel CAD, a summed difference score of 9 or greater showed a sensitivity of 46% and specificity of 90%, whereas an increase in ESV of 5 mL or greater and a decrease in EF of 5% or greater after exercise had a sensitivity of 66% and 52%, respectively, and specificity of 87% and 83%, respectively. The multivariate discriminant analysis revealed that the combination of poststress increase in ESV, summed difference score, and diabetes mellitus best identified multivessel CAD, with a sensitivity of 72% and specificity of 84% (χ2, 81.7). Conclusions: The addition of poststress and at-rest LV functional analysis by use of gated SPECT to conventional perfusion analysis helps to better identify patients with multivessel CAD. [Copyright &y& Elsevier]

Objective: Abnormal values of the transient ischemic dilation ratio (TID) according to an exercise myocardial SPECT are linked to severe coronary artery disease. The authors investigated the relationship between TID and the levels of VCAM, ICAM, E-selectin, microalbuminuria, intima-media thickness and HbA(1c) of diabetic subjects.Methods: We observed 38 subjects with diabetes type 2 (10 women, 28 men), of average age 56.08 +/- 8.24 years, with no past history of cardiovascular disease. All subjects were examined using an exercise myocardial SPECT. Transient ischemic dilation, summed stress score (SSS), summed rest score (SRS) and stress total severity score (STSS) were determined to quantify myocardial ischemia.Results: The average IMT value was 1.05 +/- 0.31 mm. The TID value was 1.02 +/- 0.154, VCAM 795.24 +/- 163.25 mg/l, ICAM 516.55 +/- 164.07, E-selectin 63.82 +/- 38.89, HbA(1c) 7.09 +/- 1.68%, microalbuminuria 68.01 +/- 55.21 mg/l. When ascertaining the relation of TID to the other factors we used Pearson's correlation at the level of significance p < 0.05. We proved a statistically significant correlation between the value of TID and glycosylated hemoglobin HbA(1c) (p = 0.035); the other factors did not show any significant correlation.Conclusion: Diabetes and its long- term unsatisfactory compensation can be one of the factors which affect left ventricular transient ischemic dilation. [ABSTRACT FROM AUTHOR]

Background: Transient ischemic dilation (TID) has been established as an important independent marker of severe and extensive coronary artery disease (CAD) in myocardial perfusion imaging (MPI). The accuracy of the TID index is dependent on a well-determined threshold (normal limits) between normal and abnormal values for each study protocol. To date, the effects of neither gender nor attenuation correction (AC) on TID normal limits have been established. Thus, the objectives of this study were to determine if AC processing changes the normal value of the TID index and if there were gender-related differences in the TID index of normal patients who had undergone rest/exercise-stress technetium-99m sestamibi MPI. Methods and Results: Seventy-five patients (33 women, 42 men; mean age, 57.7 ± 11.7 y and 55.9 ± 10.0 y, respectively) with less than a 5% likelihood of CAD, who had undergone low-dose rest/high-dose exercise-stress Tc-99m sestamibi MPI, were studied. All studies were acquired using simultaneous emission/transmission scans and were corrected for attenuation, scatter, and resolution effects using the ExSPECT II method. Both the AC and non-AC studies were analyzed using the Emory Cardiac Toolbox (ECTb; Syntermed, Inc, Atlanta, Ga) quantitative software. The TID index was calculated automatically as the ratio of stress mean left ventricular volumes to rest mean left ventricular volumes by ECTb. Patients were grouped by gender and the TID indices from AC and non-AC studies were compared. Linear regressions of the TID index and body mass index were analyzed to exclude differences in body size between male and female patients as a confounding factor in gender-related differences in TID. The TID index upper normal limits were calculated as the mean value plus 2 standard deviations (SDs). AC processing did not change the TID index significantly whether the genders were combined or separated (AC TID = 0.97 ± 0.14 vs non-AC TID = 0.98 ± 0.12 for all patients). Female patients showed higher mean TID indices than male patients in both AC (1.01 ± 0.15 vs 0.95 ± 0.12) and non-AC studies (1.00 ± 0.15 vs. 0.97 ± 0.10), but this difference was statistically significant only in AC studies (p = .03). TID indices remained constant across the range of body mass index studied. The TID index upper normal limit was 1.31 for female and 1.18 for male patients. Conclusion: TID normal values for rest/exercise-stress Tc-99m sestamibi MPI are gender-dependent and not affected by AC processing. Thus, diagnosticians should take into account these gender-related differences, as compared with the traditional value generated from mostly male populations, to ensure both men and women have the same overall accuracy of using the TID index in the diagnosis and prognosis of CAD. [Copyright &y& Elsevier]

Background: This study assessed whether transient ischemic dilation (TID) of the left ventricle is related to ischemic stunning, manifested by stress-induced decrease of left ventricular ejection fraction (LVEF) and worsening of wall motion, by use of dipyridamole-stress and redistribution thallium 201 gated single photon emission computed tomography (SPECT).Methods and Results: Ninety-two consecutive patients undergoing dipyridamole Tl-201 gated SPECT were included. Patients with a TID ratio in the highest quartile were defined as having TID. In patients with TID, end-diastolic volume (EDV) and end-systolic volume (ESV) were both significantly greater on dipyridamole-stress images than on redistribution images (P < .001). The degree of enlargement was much greater for ESV than EDV. In patients without TID, EDV and ESV were both decreased after stress (P < .001). Patients with TID had a lower mean LVEF on dipyridamole-stress images than on redistribution images (P < .001). Patients without TID had a higher mean LVEF on dipyridamole-stress images than on redistribution images (P < .001). Patients with TID had a significant worsening of global wall motion on dipyridamole-stress images than on redistribution images (P < .001), but patients without TID did not.Conclusion: TID was significantly correlated with ischemic stunning, and the enlargement of ESV was an important factor resulting in TID. [ABSTRACT FROM AUTHOR]

Background: In patients with coronary artery disease (CAD), the characteristics of those with discordant exercise thallium 201 single photon emission computed tomography (SPECT) lung uptake (lung-to-heart [L/H] ratio) and left ventricular (LV) transient ischemic dilation (LVTID) are not well defined.Methods and Results: The population included 310 patients having exercise Tl-201 SPECT and coronary angiography. The population was subclassified into 4 subgroups: increased L/H ratio only, increased LVTID only, both, and neither. The L/H ratio was weakly correlated to LVTID (r = 0.18). The L/H ratio was correlated to the summed difference score (r = 0.26), summed rest score (r = 0.31), summed stress score (r = 0.5), and rest and stress LV volume (r = 0.5 and r = 0.54, respectively). LVTID was only correlated to the summed difference score (r = 0.32) and stress LV volume (r = 0.17). Increased LVTID only was associated with more frequent ischemia and patients with it tended to be more extensively ischemic, as compared with patients with increased L/H ratio only, but had a similar angiographic extent of CAD. These results were independent of prior myocardial infarction variable.Conclusions: As compared with patients with increased L/H ratio alone, patients with increased LVTID alone are more frequently ischemic but have a similar angiographic extent of CAD. Increased L/H ratio was correlated to both rest and postexercise LV volume, whereas increased LVTID was correlated only to postexercise LV volume. [ABSTRACT FROM AUTHOR]

: ObjectivesWe sought to determine the level of angiographic stenosis at which reversible regional wall motion abnormalities (RWMA) are present on exercise stress technetium-99m (Tc-99m)– gated single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI), and whether assessments of stress and rest RWMA add incremental diagnostic information.: BackgroundStress and rest gated SPECT MPI enables the detection of post-exercise stunning. Although some studies have correlated RWMA to the severity of MPI defects, only one previous study correlated RWMA on gated MPI to angiographic findings. However, this correlation excluded patients with rest perfusion defects and did not involve gating of rest images.: MethodsOne hundred patients undergoing angiography within six months of exercise stress Tc-99m (sestamibi)–gated SPECT MPI (in the absence of interim cardiac events or revascularization) were recruited. Images were acquired 15 to 30 min after stress and interpreted without knowledge of the Duke treadmill score, left ventricular ejection fraction and angiographic data.: ResultsThe sensitivity of reversible RWMA for angiographic stenoses >70% was 53%, with a specificity of 100%. The presence of reversible RWMA was able to stratify patients with angiographic stenoses of 50% to 79% and 80% to 99% with a high positive predictive value. A good correlation was noted between the presence of reversible RWMA and the coronary artery jeopardy score (R = 0.49, p < 0.0001). Multivariate analysis showed that the post-stress RWMA, Duke treadmill and reversible RWMA scores were significant predictors of angiographic severity.: ConclusionsPost-stress and reversible RWMA, as shown by exercise stress Tc-99m–gated SPECT MPI, are significant predictors of angiographic disease and add incremental value to MPI for the assessment of angiographic severity. [Copyright &y& Elsevier]