Long-term prognosis after a normal exercise stress Tc-99m sestamibi SPECT study

Functional imaging after the "ISCHEMIA" trial

Previous randomized trials have shown a lack of benefits from the addition of revascularization to optimal medical therapy versus optimal medical therapy alone in patients with stable ischaemic heart disease at relatively low risk (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation [COURAGE]), and in diabetic patients with stable ischaemic heart disease (Bypass Angioplasty Revascularization Investigation in Type 2 Diabetics [BARI 2D]). More recently, the International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) randomized clinical trial showed similar results in patients with moderate-severe ischaemia on functional testing (imaging or stress electrocardiogram) and at least one significant (> 50%) coronary stenosis in a major epicardial coronary artery on coronarography computed coronary angiography. Although the ISCHEMIA trial adds pivotal knowledge regarding the management of and decision-making in stable patients, this study has prompted a great debate about the role of functional imaging for diagnosis, risk stratification and therapeutic decision-making. The objectives of this review are to summarize the results of the ISCHEMIA trial, to underline its limitations and to warn care providers about potential misinterpretation of this trial.

Machine Learning Algorithms to Distinguish Myocardial Perfusion SPECT Polar Maps

Myocardial perfusion imaging (MPI) plays an important role in patients with suspected and documented coronary artery disease (CAD). Machine Learning (ML) algorithms have been developed for many medical applications with excellent performance. This study used ML algorithms to discern normal and abnormal gated Single Photon Emission Computed Tomography (SPECT) images. We analyzed one thousand and seven polar maps from a database of patients referred to a university hospital for clinically indicated MPI between January 2016 and December 2018. These studies were reported and evaluated by two different expert readers. The image features were extracted from a specific type of polar map segmentation based on horizontal and vertical slices. A senior expert reading was the comparator (gold standard). We used cross-validation to divide the dataset into training and testing subsets, using data augmentation in the training set, and evaluated 04 ML models. All models had accuracy >90% and area under the receiver operating characteristics curve (AUC) >0.80 except for Adaptive Boosting (AUC = 0.77), while all precision and sensitivity obtained were >96 and 92%, respectively. Random Forest had the best performance (AUC: 0.853; accuracy: 0,938; precision: 0.968; sensitivity: 0.963). ML algorithms performed very well in image classification. These models were capable of distinguishing polar maps remarkably into normal and abnormal.

Long-term prognostic value of low-dose normal stress-only myocardial perfusion imaging by wide beam reconstruction: A competing risk analysis

BACKGROUND

A normal stress myocardial perfusion single-photon emission computed tomography (MPS) is associated with a good clinical outcome. New iterative algorithms, such as wide beam reconstruction (WBR), which improve image interpretation with half-dose or half-time acquisition, have been proposed for cardiac MPS. The aim of this study was to assess the long-term predictive value of a low-dose normal stress-only MPS with WBR using conventional Anger camera in patients with known or suspected coronary artery disease (CAD).

METHODS AND RESULTS

A total of 2106 patients with known or suspected CAD and normal perfusion at half-dose stress-only MPS protocol were followed for a mean of 6.6 ± 2.7 years. MPS data were reconstructed with WBR iterative algorithm. End-point events were cardiac death or nonfatal myocardial infarction. Noncardiac death was considered the competing event. During follow-up, 149 cardiac events occurred with an annualized event rate of 1.2%. Independent predictors of cardiac events at Cox analysis were age, male gender, diabetes mellitus, previous myocardial infarction and the need for pharmacologic stress testing. At Fine-Gray analysis the cumulative incidence of cardiac events progressively increases with age and in the presence of diabetes for any combination of gender and stress type. Survival tree analysis confirmed that long-term prognosis considerably varies according of risk factors profile.

CONCLUSIONS

Low-dose normal stress-only WBR MPS has a reliable long-term prognostic value in patients with suspected or known CAD. This finding supports the introduction of such a method into clinical practice with a consistent dose optimization in the interest of patients and exposed staff.

My warranty has expired: I need to be retested

The concept of warranty period, the duration of time during which the patient's risk remains low, is appealing. However, some points remain to be resolved before its translation in the clinical arena. Methodological issues should be standardized in order to compare the results of studies in different patient populations. Also, the definition of a "normal" study should always take into consideration the history of prior revascularization, the achieved level of exercise, and the stressor used. The promise of warranty can be questioned by the patient's baseline demographic and clinical characteristics and may also be influenced by life-style modification in the course of the follow-up. The "warranty period" concept should shift from data reflecting the time to a cardiac event to the development of ischemia, given an opportunity for intervention before a cardiac event occurs. In this context, clarify the role of serial imaging can be extremely useful, in particular to evaluate if and when retesting a patient after a normal scan.

Phase analysis single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) detects dyssynchrony in myocardial scar and increases specificity of MPI

BACKGROUND

Myocardial perfusion imaging (MPI) with single-photon emission computed tomography (SPECT) is commonly used to assess patients with cardiovascular disease. However, in certain scenarios, it may have limited specificity in the identification of hemodynamically significant coronary artery disease (e.g., false positive), potentially resulting in additional unnecessary testing and treatment. Phase analysis (PA) is an emerging, highly reproducible quantitative technology that can differentiate normal myocardial activation (synchrony) from myocardial scar (dyssynchrony). The objective of this study is to determine if PA can improve the specificity SPECT MPI.

METHODS

An initial cohort of 340 patients (derivation cohort), referred for SPECT-MPI, was prospectively enrolled. Resting MPI studies were assessed for resting perfusion defects (scar). These were utilized as the reference standard for scar. Subsequently, we collected a second independent validation cohort of 138 patients and tested the potential of PA to reclassify patients for the diagnosis of "scar" or "no scar." Patients were assigned to three categories depending upon their pre-test probability of scar based on multiple clinical and imaging parameters: ≤ 10% (no scar), 11-74% (indeterminate), and ≥ 75% (scar). The ability of PA variables to reclassify patients with scar to a higher group and those without scar to a lower group was then determined using the net reclassification index (NRI).

RESULTS

Entropy (≥ 59%) was independently associated with scar in both patient cohorts with an odds ratio greater than five. Furthermore, when added to multiple clinical/imaging variables, the use of entropy significantly improved the area under the curve for assessment of scar (0.67 vs. 0.59, p = 0.04). The use of entropy correctly reclassified 24% of patients without scar, by clinical model, to a lower risk category (as determined by pre-test probability) with an overall NRI of 18% in this validation cohort.

DISCUSSION

The use of PA entropy can improve the specificity of SPECT MPI and may serve as a useful adjunctive tool to the interpreting physician. The current study determined the optimal PA parameters to detect scar (derivation cohort) and applied these parameters to a second, independent, patient group and noted that entropy (≥ 59%) was independently associated with scar in both patient cohorts. Therefore, PA, which requires no additional imaging time or radiation, enhances the diagnostic capabilities of SPECT MPI.

CONCLUSION

The use of PA entropy significantly improved the specificity of SPECT MPI and could influence the labeling of a patient as having or not having myocardial scar and thereby may influence not only diagnostic reporting but also potentially prognostic determination and therapeutic decision-making.

Negative predictive value of stress myocardial perfusion imaging and coronary computed tomography angiography: A meta-analysis

BACKGROUND

Comparing the prognostic value of a negative finding by stress single-photon emission computed tomography myocardial perfusion imaging (MPI) and coronary computed tomography angiography (CCTA) may be useful to evaluate how better identify low-risk patients. We performed a meta-analysis to compare the long-term negative predictive value (NPV) of normal stress MPI and normal CCTA in subjects with suspected coronary artery disease (CAD).

METHODS AND RESULTS

Studies published between January 2000 and November 2016 were identified by database search. We included MPI and CCTA studies that followed-up ≥100 subjects for ≥5 years and providing data on clinical outcome for patients with negative tests. Summary risk estimates for normal perfusion at MPI or <50% coronary stenosis at CCTA were derived in random effect regression analysis, and causes of heterogeneity were determined in meta-regression analysis. We identified 12 eligible articles (6 MPI and 6 CCTA) including 33,129 patients (26,757 in MPI and 6372 in CCTA studies) with suspected CAD. The pooled annualized event rate (AER) for occurrence of hard events (death and nonfatal myocardial infarction) was 1.06 (95% confidence interval, CI 0.49-1.64) in MPI and 0.61 (95% CI 0.35-0.86) in CCTA studies. The pooled NPV was 91% (95% CI 86-96) in MPI and 96 (95% CI 95-98) in CCTA studies. The summary rates between MPI and CCTA were not statistically different. At meta-regression analysis, no significant association between AER and clinical and demographical variables considered was found for overall studies.

CONCLUSIONS

Stress MPI and CCTA have a similar ability to identify low-risk patients with suspected CAD.

Long-term prognosis of end-stage renal disease patients with normal myocardial perfusion as determined by single photon emission computed tomography

BACKGROUND/AIMS

Normal myocardial perfusion is closely associated with very low rates of cardiac events and better long-term outcomes; however, little is known about its prognostic value in patients with end-stage renal disease (ESRD).

METHODS

A total of 286 incident patients underwent baseline cardiac evaluations using echocardiography and stress-rest single-photon emission computed tomography. Perfusion scans for 177 patients (61.9%) who had a summed stress score (SSS) < 4 were normal.

RESULTS

During the 4-year follow-up period, 79 cardiac events occurred. Patients with a SSS < 4 had significantly lower annual rates of cardiac events than did those with a SSS ≥ 4 (6.4% vs. 13.2%; hazard ratio, 0.54; 95% confidence interval, 0.31 to 0.94). Among patients with a SSS < 4, however, cardiac event rates significantly differed according to the presence of comorbid conditions such as old age, diabetes, history of coronary artery disease, and elevated C-reactive protein levels. In addition, the presence of left ventricular (LV) systolic dysfunction and LV hypertrophy at the start of hemodialysis strongly influenced future cardiac events.

CONCLUSIONS

In patients with ESRD, normal perfusion scans usually indicate a significantly low risk of adverse cardiac events. However, even in patients with normal perfusion scans, the cardiovascular prognosis is largely dependent on baseline inflammation levels and comorbidities.

Outcome of revascularisation in stable coronary artery disease without ischaemia: a Danish registry-based follow-up study

OBJECTIVES

In stable coronary artery disease (CAD), coronary revascularisation may reduce mortality of patients with a certain amount of left ventricular myocardial ischaemia. However, revascularisation does not always follow the guidance suggested by ischaemia testing. We compared outcomes in patients without ischaemia who had either revascularisation or medical treatment.

DESIGN AND POPULATION

Based on registries, 1327 consecutive patients with normal myocardial perfusion scintigraphy (MPS) and 278 with fixed perfusion defects were followed for a median of 6.1 years. Most patients received medical therapy alone (Med), but 26 (2%) with a normal MPS and 15 (5%) with fixed perfusion defects underwent revascularisation (Revasc).

OUTCOME MEASURES

Incidence rates of all-cause death (ACD) and rates of cardiac death/myocardial infarction (CD/MI).

RESULTS

With a normal MPS, the ACD rate was 6.2%/year in the Revasc group versus 1.9%/year in the Med group (p=0.01); the CD/MI rates were 6.9%/year and 0.6%/year, respectively (p<0.00001). Results persisted after adjustment for predictors of revascularisation, in particular angina score, and in comparisons of matched Revasc and Med patients. With fixed defects, the ACD rate was 9.1%/year in the Revasc group and 6.7%/year in the Med group (p=0.44); the CD/MI rate was 5.0%/year versus 4.2%/year, respectively (p=0.69). If adjusted for angiographic variables or analysed in matched subsets, differences remained insignificant.

CONCLUSIONS

With normal MPS, revascularisation conferred a higher risk, even after adjustment for predictors of revascularisation. With fixed defects, the Revascversus Med difference was close to equipoise. Hence, in patients with stable CAD without ischaemia, we could not find evidence to justify exceptional revascularisation.

High prevalence of coronary artery calcification in Saudi patients with normal myocardial perfusion

BACKGROUND

Normal single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) has a high negative predictive value for ischemic heart disease. Thus, the presence of subclinical coronary atherosclerosis detected by coronary artery calcification (CAC) score in patients who have under-gone SPECT MPI is unknown.

OBJECTIVES

Determine the prevalence of coronary artery calcification (CAC) in patients with normal SPECT MPI and examine the association of CAC with conventional coronary artery disease (CAD) risk factors.

DESIGN

Cross-sectional analytical study using medical records from February 2010 to April 2016.

SETTINGS

Single tertiary-care center.

PATIENTS AND METHODS

We studied patients referred from the outpatient clinical services for clinically indicated noninvasive CAD diagnosis with MPI SPECT. CAC scoring was subsequently performed within 3 months after a normal MPI. We excluded patients with chest pain or decompensated heart failure or patients with a history of CAD. The study population was divided into three groups: patients with a CAC score of 0, a CAC score from 1 to 300, and a CAC score more than 300. The groups were analyzed by age and other demographic and clinical characteristics.

MAIN OUTCOME MEASURE(S)

Prevalence of CAC in patients with normal MPI.

RESULTS

The prevalence of CAC was 55% (n=114) in 207 patients with a mean (SD) age of 57.1 (10.4) years. Twelve percent had severe coronary atherosclerosis (CAC score > 300). All patients had a normal MPI SPECT. CAC scores were 0 for 93 patients (45%), 1 to 300 for 89 (43%), and more than 300 for 24 (12%). There was a strong association between CAC score and age (P < .0001), male sex (P < .0001), and diabetes mellitus (P=.042), but no association between CAC score and hypertension (P=.153), family history of CAD (P=.23), obesity (P=.31), hypercholesterolemia (P=.071), or smoking (P=.308).

CONCLUSIONS

The prevalence of CAC is high in this study population of patients with normal SPECT MPI. Age, male sex and diabetes were risk factors associated with CAC.

LIMITATIONS

Single center and small study population.

Role of risk stratification by SPECT, PET, and hybrid imaging in guiding management of stable patients with ischaemic heart disease: expert panel of the EANM cardiovascular committee and EACVI

Risk stratification has become increasingly important in the management of patients with suspected or known ischaemic heart disease (IHD). Recent guidelines recommend that these patients have their care driven by risk assessment. The purpose of this position statement is to summarize current evidence on the value of cardiac single-photon emission computed tomography, positron emission tomography, and hybrid imaging in risk stratifying asymptomatic or symptomatic patients with suspected IHD, patients with stable disease, patients after coronary revascularization, heart failure patients, and specific patient population. In addition, this position statement evaluates the impact of imaging results on clinical decision-making and thereby its role in patient management. The document represents the opinion of the European Association of Nuclear Medicine (EANM) Cardiovascular Committee and of the European Association of Cardiovascular Imaging (EACVI) and intends to stimulate future research in this field.

Warranty periods for normal myocardial perfusion stress SPECT

BACKGROUND

To assess different warranty periods following a normal myocardial perfusion SPECT based on patients' clinical characteristics and the type of stress performed.

METHODS AND RESULTS

A study was done of 2,922 consecutive patients (62.9 ± 13 years; 53.4% women) with a normal stress-rest SPECT. The warranty period was defined as the period during which patients remained at a low risk (<1% events/year) of total mortality (TM), or hard events (HE) (cardiac death or non-fatal myocardial infarction). Of these patients, 2,051 were given an exercise myocardial perfusion imaging (Ex-MPI); 461 submaximal exercise plus dipyridamole (Ex+Dipy-MPI); and 410 dipyridamole (Dipy-MPI). During a mean follow-up of 5 ± 3.3 years, a significant reduction (P < .05) of the warranty period for TM (13.5, 9.6 and 8 months) and HE (34.8, 20.5 and 8.2 months) was observed, for Ex-MPI, Ex+Dipy-MPI and Dipy-MPI, respectively. Other warranty period determinants were the clinical variables of age, sex, diabetes and known coronary artery disease. An abnormal left ventricular ejection fraction on gated-SPECT also significantly shortened the warranty period for HE in patients undergoing Ex+Dipy-MPI (P = .001) or Dipy-MPI alone (P = .007).

CONCLUSIONS

The warranty period for a normal stress-rest SPECT is highly variable since it is primarily determined by the type of stress, the patient's clinical characteristics and LVEF.

Long-term mortality following normal exercise myocardial perfusion SPECT according to coronary disease risk factors

BACKGROUND

While normal exercise myocardial perfusion imaging (SPECT-MPI) is a robust predictor of low short-term clinical risk, there is increasing interest in ascertaining how clinical factors influence long-term risk following SPECT-MPI.

METHODS

We evaluated the predictors of outcome from clinical data obtained at the time of testing in 12,232 patients with normal exercise SPECT-MPI studies. All-cause mortality (ACM) was assessed at a mean of 11.2 ± 4.5 years using the Social Security Death Index.

RESULTS

The ACM rate was 0.8%/year, but varied markedly according to the presence of CAD risk factors. Hypertension, smoking, diabetes, exercise capacity, dyspnea, obesity, higher resting heart rate, an abnormal ECG, LVH, atrial fibrillation, and LVEF < 45% were all predictors of increased mortality. Risk factors were synergistic in predicting mortality: annualized age and gender-adjusted ACM rates ranged from only 0.2%/year among patients exercising for >9 minutes having none of three significant risk factors (among hypertension, diabetes, and smoking) to 1.6%/year among patients exercising <6 minutes and having ≥ 2 of these three risk factors. The age and gender-adjusted hazard ratio for mortality was increased by 7.3 (95% confidence interval 5.5-9.7) in the latter patients compared to those patients who exercised >9 minutes and had no significant risk factors (P < .001).

CONCLUSIONS

Long-term mortality risk varies markedly in accordance with baseline CAD risk factors and functional capacity among patients with normal exercise SPECT-MPI studies. Further study is indicated to determine whether the prospective characterization of both short-term and long-term risks following the performance of stress SPECT-MPI leads to improved clinical management.

[Variables that influence the indication of a second myocardial perfusion gated-SPECT after a normal stress-rest gated SPECT]

OBJECTIVE

The objective of this study was to investigate predictor variables at the moment of normal stress-rest myocardial perfusion gated SPECT for indication of a second gated SPECT.

MATERIAL AND METHODS

A prospective, single center cohort study was conducted. We evaluated 2326 consecutive patients (age 63.6 ± 13 years, 57.3% females) without perfusion defects and with normal left ventricular ejection fraction on a myocardial perfusion gated SPECT. Clinical and stress test variables were studied to predict indication of a second gated SPECT and presence of reversible perfusion defects in the second gated SPECT.

RESULTS

During a mean follow-up of 3.6 ± 2 years a second gated SPECT was performed in 286 patients (12.3%). Independent predictor variables of a second gated SPECT were presence of three or more cardiovascular risk factors (χ(2): 5.510; HR: 1.4; p=0.019), previous acute myocardial infarction (χ(2): 3.867; HR: 1.4; p=0.049), previous coronary revascularization (χ(2): 41.081; HR: 2.5; p<0.001), and a positive stress test (χ(2): 8.713; HR: 1.5; p=0.003). Observation of perfusion defects in the 280 patients in whom a second stress-rest gated SPECT was performed was more likely in male patients (χ(2): 4.322; HR: 1.9; p=0.038) who had a first pure pharmacological gated-SPECT (χ(2): 7.182; HR: 2.6; p=0.007).

CONCLUSIONS

In patients with a first normal myocardial perfusion gated SPECT, various clinical factors and variables derived from the stress test affect the indication of a second gated SPECT and the presence of ischemia in the latter.

Prognosis in patients with suspected or known ischemic heart disease and normal myocardial perfusion: long-term outcome and temporal risk variations

BACKGROUND

The prognostic value of a normal myocardial perfusion scintigraphy (MPS) may be well described, but long-term follow-up data are sparse, and temporal variations in risk are insufficiently elucidated.

METHODS AND RESULTS

During long-term follow-up (mean 6.2 years) of 1,327 consecutive Danish patients with normal MPS, the rate of all-cause death (ACD) was 1.9%/year (differing by gender) and of cardiac death (CD)/myocardial infarction (MI) 0.8%/year (differing by coronary artery disease, CAD). Female gender (HR: 0.60), age (HR: 1.07 per-year increment), and known CAD without prior revascularization (HR: 2.17) were statistically significant factors for ACD, whereas diabetes and previous MI per se were not. Known CAD with previous revascularization carried a low risk of ACD when adjusted for gender and age (HR: 0.56). For CD/MI, risk increased with age and threefold with known CAD, previous MI, and previous percutaneous coronary intervention. Judged from smoothed hazard functions, mortality risk increased further with time for men, elderly, and diabetics and markedly further with known CAD without prior revascularization.

CONCLUSIONS

Following a normal MPS, rates of death and hard cardiac events were low. Risk varied with age, gender, and disease history. Novel aspects of temporal risk variation suggested a general warranty period of 5 years, but less in risk groups.

Patients with left bundle branch block pattern and high cardiac risk myocardial SPECT: does the current management suffice?

INTRODUCTION

Myocardial perfusion SPECT (MPS) is frequently used for cardiovascular risk stratification. The significance of MPS in patients with abnormal electrical ventricular activation is often questionable. This review assesses the value of MPS for risk stratification of patients with intrinsic left bundle branch block or that due to right ventricular apical pacing.

METHODS

We reviewed the literature by a search of the MEDLINE database (January 1980 to September 2010). The terms prognosis or prognostic value were combined with SPECT and LBBB or pacing or pacemakers. MPS was categorised as low and high risk according to the original definitions.

RESULTS

We identified 11 studies suitable for review. A low-risk MPS is associated with a low risk of cardiac events whereas high-risk MPS carries a 4.8-fold increased risk, 95% CI [3.2 - 7.2] (p < 0.0001). Despite secondary prevention and an improved medical and interventional care, these figures have hardly changed over time.

CONCLUSION AND CLINICAL IMPLICATIONS

A low-risk MPS permits a policy of watchful waiting whereas a high-risk MPS requires further analysis and treatment. The persistent high cardiac death and acute myocardial infarction rate after a high-risk MPS suggest that the current management of these patients does not suffice and needs reconsideration.

15-Year outcome after normal exercise ⁹⁹mTc-sestamibi myocardial perfusion imaging: what is the duration of low risk after a normal scan?

OBJECTIVE

The goal of this study was to evaluate the very long-term outcome after normal exercise (99m)Tc-sestamibi myocardial perfusion single-photon emission computed tomography (SPECT). Exercise (99m)Tc-sestamibi SPECT is widely used for risk stratification, but data on very long-term outcome after a normal test are scarce.

METHODS

A consecutive group of 233 patients (122 men, mean age 54 ± 12 years) with known or suspected coronary artery disease (CAD) underwent exercise (99m)Tc-sestamibi SPECT and had normal myocardial perfusion at exercise and at rest. Follow-up endpoints were all-cause mortality, cardiac mortality, nonfatal myocardial infarction, and coronary revascularization. Predictors of outcome were identified by Cox proportional hazard regression models using clinical and exercise testing variables.

RESULTS

During a mean follow-up of 15.5 ± 4.9 years, 41 (18%) patients died, of which 13 were cardiac deaths. A total of 18 (8%) patients had a nonfatal myocardial infarction, and 47 (20%) had coronary revascularization. The annualized event rates for all-cause mortality, cardiac mortality, cardiac mortality/nonfatal infarction, and major adverse cardiac events were, respectively, 1.1%, 0.3%, 0.7%, and 1.8%. Multivariate analysis demonstrated that the variables age, male gender, diabetes, diastolic blood pressure at rest, rate pressure product at rest, peak exercise heart rate, and ST segment changes were independent predictors of major adverse cardiac events.

CONCLUSION

Patients with suspected or known CAD and normal exercise (99m)Tc-sestamibi myocardial perfusion SPECT have a favorable 15-year prognosis. Follow-up should be closer in patients with known CAD, and/or having clinical and exercise parameters indicating higher risk status.

Comparative Analysis between SPECT Myocardial Perfusion Imaging and CT Coronary Angiography for Diagnosis of Coronary Artery Disease

The study aims to discuss the relationship and difference between myocardial perfusion imaging (MPI) using SPECT and CT coronary angiography (CTCA) for diagnosis of coronary artery disease (CAD). Five hundred and four cases undergoing MPI and CTCA were comparatively analyzed, including fifty six patients undergoing invasive coronary angiography in the same period. Among patients with negative MPI results, negative or positive CTCA occupied 84.7% or 15.3%, respectively. Among patients with positive MPI, positive or negative CTCA occupied 67.2% or 32.8%, respectively. Among patients with negative CTCA, negative or positive MPI occupied 94.4% or 5.6%, respectively. Among patients with positive CTCA, positive or negative MPI occupied 40.2% or 59.8%, respectively. Negative predictive value was relatively higher than the positive predictive value for positive CTCA eliminating or predicting abnormal haemodynamics. And there was no significant difference for sensitivity, specificity, and accuracy of MPI or CTCA in diagnosing CAD. Both MPI and CTCA have good diagnostic performance for CAD. They provide different and complementary information for diagnosis and evaluation of CAD, namely, detection of ischemia versus detection of atherosclerosis, which are quite different but have a definite internal link for each other.

Prognostic implications of post-stress ejection fraction decrease detected by gated SPECT in the absence of stress-induced perfusion abnormalities

PURPOSE

The prognostic meaning of a post-stress ejection fraction (EF) decrease detected by perfusion gated SPECT is still unclear.We therefore followed up patients with post-stress EF decrease in the absence of stress-induced perfusion abnormalities.

METHODS

We prospectively enrolled 57 consecutive patients with post-stress EF drop ≥ 5 EF units and summed difference score (SDS) ≤ 1. They were followed up for more than 1 year and their outcome was compared with a group of sex- and age-matched controls with the same SDS but without EF decrease.

RESULTS

During follow-up there were 13 events (1 cardiac death, 1 non-fatal myocardial infarction, 1 congestive heart failure and 10 late revascularizations). In the control group we registered six events. There was a significant difference (p<0.0001) between the event-free survival curves of the two groups.

CONCLUSION

The event rate of patients with post-stress EF decrease ≥ 5 EF units is relatively high and is significantly worse than that of a control group of patients with similarly normal SDS but without EF changes. Therefore, a post-stress EF decrease without stress-induced perfusion abnormalities should be cautiously interpreted.

Cardiovascular outcomes are predicted by exercise-stress myocardial perfusion imaging: Impact on death, myocardial infarction, and coronary revascularization procedures

BACKGROUND

The aim of this study was to determine the impact of myocardial perfusion imaging (MPI) on the outcomes of death, myocardial infarction (MI), and late coronary revascularization procedures.

METHODS

In patients undergoing exercise-stress MPI (January 1, 2003-March 31, 2007), we determined the impact of summed stress score (SSS) and percent left ventricular (LV) ischemia on (a) death or MI and (b) composite of death, MI, or late coronary revascularization occurring more than 90 days post-MPI.

RESULTS

During 35,007 person-years of follow-up among 9,605 patients (mean ± SD age 54.4 ± 13.2 years, 60.3% men), there were 290 deaths, 175 MIs, and 525 coronary revascularization procedures. Of those who attained ≥10 metabolic equivalents (METS) workload, major stress perfusion defects (SSS ≥7) were present in 4.2% overall and in 3.7% without ST-segment shifts, whereas large ischemic defects (≥10% LV ischemia) were present in 1% overall and 0.7% without ST-segment shifts. For those with 1% to 4%, 5% to 9%, and ≥10% LV ischemia, adjusted hazard ratios were 1.40 (95% CI 1.13-1.73, P = .002), 2.07 (95% CI 1.56-2.74, P < .001), and 3.03 (95% CI 2.21-4.16, P < .001) for the outcome of late revascularization, MI, or death versus no ischemia. Summed stress scores ≥7 were associated with increased risk of death or MI, with an adjusted hazard ratio of 1.57 (95% CI 1.16-2.13, P = .004) compared with those with no stress perfusion defects.

CONCLUSION

Although workload ≥10 METS conferred lower frequency of major ischemia (≥10%), %LV ischemia predicted the occurrence of cardiovascular events and death (eg, MI, late coronary revascularization, or death). Presence of a large stress perfusion defect (SSS ≥7) predicted increased risk of MI or death.

One-year prognosis of patients with normal myocardial perfusion imaging using technitium-99m sestamibi in suspected coronary artery disease: a single-center experience of 1,047 patients

INTRODUCTION

The aim of the present study was to evaluate the clinical outcome of a normal stress technetium-99m (99mTc)-Sestamibi single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) with different probabilities of coronary artery disease (CAD).

MATERIAL AND METHODS

A total of 1,047 subjects with a normal 99mTc-MIBI SPECT were followed up for one year and hard and soft cardiac events were assessed. Hard cardiac events were defined as cardiac death or non-fatal myocardial infarction (MI). Soft cardiac events included the patient's development of recurrent chest pain requiring coronary revascularization or significant stenosis in coronary arteries on angiography.

RESULTS

Overall, 1,047 patients (248 men and 799 women; mean age: 60.07 ± 12.31, range 29-92) were enrolled. Three hard cardiac events occurred in the groups; two had cardiac arrest and one non-fatal MI. As a result, the annualized hard cardiac event rate was 0.28%, the annualized cardiac mortality rate was 0.19%, and the rate of overall annualized cardiac events was 1.25%. Furthermore, there was a significant difference in cardiac events among patients with various pretest likelihoods of CAD (p value=0.04).

CONCLUSION

Our data confirmed that patients with a normal 99mTc-Sestamibi myocardial SPECT are associated with a very low incidence of cardiovascular events.

Immediate computed tomography coronary angiography versus delayed outpatient stress testing for detecting coronary artery disease in emergency department patients with chest pain

Noninvasive testing for coronary artery disease (CAD) is warranted for symptomatic patients with intermediate pretest likelihood of CAD. Accomplishing testing in an emergency department (ED) environment is challenging. We compared two strategies of CAD testing in ED patients: immediate computed tomography coronary angiography (CTCA) versus delayed outpatient stress testing. We conducted a historical control cohort study comparing symptomatic ED patients without an acute coronary syndrome who warranted noninvasive CAD testing. Two cohorts (50 patients each) were defined by CAD testing strategy, immediate CTCA versus delayed stress testing. Outcomes were duration of ED stay, detection of CAD, and 3-month rates of readmission, myocardial infarction, (MI) or death. Median duration of stay was 417.5 minutes (interquartile range [IQR] 359.0-581.0) in the CT cohort and 400.0 minutes (IQR 338.0-471.0) in the control cohort (P = 0.53). CAD was detected in 14 CT cohort patients versus 1 in control (P = 0.0004), due to low follow-up in the control cohort (18 of 50, 36%). Obstructive CAD was diagnosed in 6 CT cohort patients versus 1 in control (P = 0.11). During 3 months of follow-up, four patients in each cohort were reevaluated in the ED for chest pain; no patients suffered MI or death. A strategy of immediate CTCA is superior to a delayed stress testing strategy for detecting CAD in ED patients with chest pain and prompting appropriate referrals for further management. Delayed stress testing was primarily ineffective due to low follow-up. Immediate CTCA can be used safely without altering the ED duration of stay.

Synergistic effect of coronary artery disease risk factors on long-term survival in patients with normal exercise SPECT studies

BACKGROUND

Normal exercise single-photon emission computed tomography (SPECT) studies are associated with a low event rate (<1.0%/year) during short-term follow-up. The influence of cardiac risk factors on long-term outcomes in such patients has not been well studied.

MATERIAL AND METHODS

2,597 patients (55 ± 12 years, male 41%) without a history of heart disease and a normal exercise SPECT between the years 1995 and 2006 were followed for a mean 6.8 ± 3.1 years for all-cause mortality assessed for using the Social Security Death Index. Baseline clinical risk factors and other clinical information were recorded for each patient and compared to outcomes.

RESULTS

The mortality rate was 0.9%/year for our overall study population but varied according to individual baseline risk factors. Three coronary artery disease (CAD) risk factors were significant predictors of all-cause mortality: hypertension, diabetes, and smoking. When all three were absent, long-term all-cause mortality rate averaged 0.2%/year and when all three were present, all-cause mortality averaged 1.8%/year, constituting a 5.7-fold adjusted increase in risk (95% CI 2.7-12.8, P < .0001).

CONCLUSIONS

During follow-up, annualized mortality rate varies markedly according to the number of CAD risk factors in patients without known heart disease and a normal exercise SPECT stress. Despite overall excellent long-term prognosis of a normal exercise SPECT, the burden of traditional CAD risk factors exert a strong synergistic influence on long-term survival and warrant aggressive treatment in this patient population.

Myocardial perfusion SPECT identifies patients with left bundle branch block patterns at high risk for future coronary events

BACKGROUND

The value of myocardial perfusion SPECT (MPS) for patients with left bundle branch block (LBBB) or right ventricular apical (RVA) pacing seems reduced. The prognosis of patients with only abnormal activation related perfusion defects (AARD) due to LBBB or RVA-pacing is similar to those with a normal MPS. We assessed the prognostic value of MPS in patients with LBBB or RVA pacing.

METHODS

Patients with LBBB or RVA pacing referred for vasodilator stress MPS between April 2002 and January 2006 were analyzed. Group 1 are patients with normal MPS and MPS with AARD. Group 2 are patients with an MPS with a perfusion defect extending outside the AARD area. Events were cardiac death, acute myocardial infarction and coronary revascularization.

RESULTS

In Group 1 (101 patients) 12 events and in Group 2 (96 patients) 45 events occurred during a mean follow-up of 2.6 +/- 1.5 years. The prognosis of Group 2 was significantly worse (49%) compared with Group 1 (91%). The annual cardiac death rate was 0.7%/year in Group 1 and 6.4%/year in Group 2 (P < .001). The prognosis of patients with LBBB was not different from those with RVA pacing.

CONCLUSION

Group 2 had a significantly worse cardiac prognosis compared to Group 1. The annual cardiac death rate of <1% in Group 1 warrants a watchful waiting strategy, whereas the cardiac death rate in Group 2 warrants aggressive invasive coronary strategies.

The value of multi-slice-computed tomography coronary angiography for risk stratification

Multi-slice-computed tomography coronary angiography (CTA) provides direct non-invasive anatomic assessment of the coronary arteries allowing for early identification of coronary artery disease (CAD). This information is useful for diagnosis of CAD, particularly the rule out of CAD. In addition, early identification of CAD with CTA may also be useful for risk stratification. The purpose of this review is to provide an overview of the current literature on the prognostic value of CTA and to discuss how the prognostic information obtained with CTA can be used to further integrate the technique into clinical practice. Non-invasive anatomic assessment of plaque burden, location, composition, and remodeling using CTA may provide prognostically relevant information. This information has been shown to be incremental to the Framingham risk score, coronary artery calcium scoring, and myocardial perfusion imaging. Characterization of atherosclerosis non-invasively has the potential to provide important prognostic information enabling a more patient-tailored approach to disease management.Future studies assessing outcome after CTA-based risk adjustments are needed to further understand the value of detailed non-invasive anatomic imaging.

Risk stratification by adenosine stress cardiac magnetic resonance in patients with coronary artery stenoses of intermediate angiographic severity

OBJECTIVES

The purpose of this study was to determine the role of adenosine stress cardiac magnetic resonance (CMR) for risk stratification in patients with coronary artery stenoses of intermediate angiographic severity.

BACKGROUND

Coronary angiography only provides a morphological description of coronary lesions. As the patient's prognosis is closely related to the functional significance of angiographically detected coronary lesions, a functional assessment is desirable in patients with coronary artery stenoses of intermediate severity.

METHODS

Myocardial perfusion measurements at rest and adenosine stress were performed on 81 patients (75.6% male, mean age 64.2 years) with stable angina pectoris (AP) and coronary artery stenoses of intermediate angiographic severity (50% to 75%). Regardless of the CMR result, all patients were treated conservatively with an intensified medical treatment, and a follow-up was performed after 18 +/- 8 months and 30 +/- 8 months. The primary end point was defined as a major adverse cardiac event (MACE): all-cause death, stroke, acute coronary syndrome; the secondary end point was defined as target vessel revascularization. Furthermore, AP and dyspnea were evaluated.

RESULTS

After the follow-up period of 30 +/- 8 months, 9 patients with perfusion deficit (PD) suffered from MACE, whereas no MACE occurred among the 36 patients without PD (p = 0.014). Among patients who had MACE, the number of ischemic segments (2.3 +/- 1.6 vs. 1.4 +/- 1.6, p = 0.0025) was significantly higher, whereas the number of delayed enhancement segments did not differ (1.4 +/- 1.6 vs. 1.6 +/- 2.3, p = 0.4). Target vessel revascularization was required in 38% of patients with PD and 6% of patients without PD (p = 0.005). In addition, the percentage of freedom from AP and dyspnea at the follow-up after 18 +/- 8 months was significantly lower among patients without perfusion deficit (69.4% vs. 15.6%; p = 0.0001). After a follow-up period of 30 +/- 8 months, the rate of AP (11.1% vs. 8.3%, p = 0.33) as well as the percentage of patients free of symptoms was similar in both groups (77.8% vs. 88.9%, p = 0.82).

CONCLUSIONS

Adenosine stress CMR may help to identify patients at risk who benefit from intensified medical treatment and close follow-up.

The prognostic significance of typical perfusion defects on vasodilator stress myocardial perfusion SPECT in patients with left bundle branch block or right ventricular apical pacing

PURPOSE

Left bundle branch block (LBBB) and ventricular pacing may induce typical artefacts that appear as perfusion defects in myocardial perfusion single photon emission computed tomography (MPS). We assessed the prognosis of patients with LBBB or right ventricular apical (RVA) pacing who had chest pain and an MPS with only abnormal activation-related defects (AARD).

METHODS

All patients with LBBB or ventricular pacing referred for vasodilator stress MPS between April 2002 and January 2006 were analyzed. AARD were defined as small, nontransmural, fixed defects and small reversible defects in well-defined regions always accompanied with concomitant wall motion abnormalities.

RESULTS

Ninety-seven patients were included, with a mean follow-up period of 3+/-1.3 years. MPS showed AARD in 57 and it was completely normal in 40 patients. No significant difference in cumulative cardiac event-free follow-up was observed between patients with AARD (93%) and normal MPS (85%). The average annual cardiac event rate was not significantly different between the groups (1.7 and 4.3% per year, respectively). No difference was found between patients with LBBB and RVA pacing.

CONCLUSION

Patients with chest pain and LBBB or RVA pacing who show AARD on MPS have a comparable prognosis as patients with abnormal activation and a normal MPS. This justifies MPS for risk stratification of patients with chest pain and LBBB or RVA pacing.

Non-invasive cardiac imaging techniques and vascular tools for the assessment of cardiovascular disease in type 2 diabetes mellitus

Cardiovascular disease is the major cause of mortality in type 2 diabetes mellitus. The criteria for the selection of those asymptomatic patients with type 2 diabetes who should undergo cardiac screening and the therapeutic consequences of screening remain controversial. Non-invasive techniques as markers of atherosclerosis and myocardial ischaemia may aid risk stratification and the implementation of tailored therapy for the patient with type 2 diabetes. In the present article we review the literature on the implementation of non-invasive vascular tools and cardiac imaging techniques in this patient group. The value of these techniques as endpoints in clinical trials and as risk estimators in asymptomatic diabetic patients is discussed. Carotid intima-media thickness, arterial stiffness and flow-mediated dilation are abnormal long before the onset of type 2 diabetes. These vascular tools are therefore most likely to be useful for the identification of 'at risk' patients during the early stages of atherosclerotic disease. The additional value of these tools in risk stratification and tailored therapy in type 2 diabetes remains to be proven. Cardiac imaging techniques are more justified in individuals with a strong clinical suspicion of advanced coronary heart disease (CHD). Asymptomatic myocardial ischaemia can be detected by stress echocardiography and myocardial perfusion imaging. The more recently developed non-invasive multi-slice computed tomography angiography is recommended for exclusion of CHD, and can therefore be used to screen asymptomatic patients with type 2 diabetes, but has the associated disadvantages of high radiation exposure and costs. Therefore, we propose an algorithm for the screening of asymptomatic diabetic patients, the first step of which consists of coronary artery calcium score assessment and exercise ECG.

Incidence and prognostic implication of unrecognized myocardial scar characterized by cardiac magnetic resonance in diabetic patients without clinical evidence of myocardial infarction

BACKGROUND

Silent myocardial infarctions (MIs) are prevalent among diabetic patients and inflict significant morbidity and mortality. Although late gadolinium enhancement (LGE) imaging by cardiac magnetic resonance (CMR) can provide sensitive characterization of myocardial scar, its prognostic significance in diabetic patients without any clinical evidence of MI is unknown.

METHODS AND RESULTS

We performed clinically indicated CMR imaging in 187 diabetic patients who were grouped by the absence (study group, n=109) or presence (control group, n=78) of clinical evidence of MI (clinical history of MI or Q waves on ECG). CMR imaging and follow-up were successful in 107 study patients (98%) and 74 control patients (95%). Cox regression analyses were performed to associate LGE with major adverse cardiovascular events (MACE), including death, acute MI, new congestive heart failure or unstable angina, stroke, and significant ventricular arrhythmias. LGE by CMR was present in 30 of 107 study patients (28%). At a median follow-up of 17 months, 38 of 107 patients (36%) experienced MACE, which included 18 deaths. Presence of LGE was associated with a >3-fold hazards increase for MACE and for death (hazard ratio, 3.71 and 3.61; P<0.001 and P=0.007, respectively). Adjusted to a model that combines patient age, sex, ST or T changes on ECG, and left ventricular end-systolic volume index, LGE maintained a >4-fold hazards increase for MACE (adjusted hazard ratio, 4.13; 95% confidence interval, 1.74 to 9.79; P=0.001). In addition, LGE provided significant prognostic value with MACE and with death adjusted to a diabetic-specific risk model for 5-year events. The presence of LGE was the strongest multivariable predictor of MACE and death by stepwise selection in the study patients.

CONCLUSIONS

CMR imaging can characterize occult myocardial scar consistent with MI in diabetic patients without clinical evidence of MI. This imaging finding demonstrates strong association with MACE and mortality hazards that is incremental to clinical, ECG, and left ventricular function combined.

The Prognostic Value of Normal Exercise Myocardial Perfusion Imaging and Exercise Echocardiography

OBJECTIVES

The purpose of this work was to determine the prognostic value of normal exercise myocardial perfusion imaging (MPI) tests and exercise echocardiography tests, and to determine the prognostic value of these imaging modalities in women and men.

BACKGROUND

Exercise MPI and exercise echocardiography provide prognostic information that is useful in the risk stratification of patients with suspected coronary artery disease (CAD).

METHODS

We searched the PubMed, Cochrane, and DARE databases between January 1990 and May 2005, and reviewed bibliographies of articles obtained. We included prospective cohort studies of subjects who underwent exercise MPI or exercise echocardiography for known or suspected CAD, and provided data on primary outcomes of myocardial infarction (MI) and cardiac death with at least 3 months of follow-up. Secondary outcomes (unstable angina, revascularization procedures) were abstracted if provided. Studies performed exclusively in patients with CAD were excluded.

RESULTS

The negative predictive value (NPV) for MI and cardiac death was 98.8% (95% confidence interval [CI] 98.5 to 99.0) over 36 months of follow-up for MPI, and 98.4% (95% CI 97.9 to 98.9) over 33 months for echocardiography. The corresponding annualized event rates were 0.45% per year for MPI and 0.54% per year for echocardiography. In subgroup analyses, annualized event rates were <1% for each MPI isotope, and were similar for women and men. For secondary events, MPI and echocardiography had annualized event rates of 1.25% and 0.95%, respectively.

CONCLUSIONS

Both exercise MPI and exercise echocardiography have high NPVs for primary and secondary cardiac events. The prognostic utility of both modalities is similar for both men and women.

Myocardial perfusion imaging in the elderly: a review

Coronary artery disease is a major cause of morbidity and mortality in the elderly population. As a result of ageing of the population and better medical, interventional and surgical treatment of patients with coronary artery disease, more and more elderly patients are referred to the cardiology department for diagnostic work-up. Stress testing, in combination with myocardial perfusion imaging, is routinely used in elderly patients, a population in which the diagnosis of significant coronary artery disease is often challenging because of atypical symptomatology. Since the introduction of technetium-99m ligands for myocardial perfusion imaging, it is possible to perform electrocardiogram-gated perfusion imaging. This not only improves the specificity of the test for coronary artery disease detection, but also enables the simultaneous assessment of left ventricular functional parameters. This article briefly overviews the possible stress modalities, diagnostic accuracy and prognostic value of myocardial perfusion imaging in elderly patients.

Prognostic value of normal exercise 99mTc-sestamibi myocardial tomography in patients with angiographic coronary artery disease

BACKGROUND AND AIM

Previous studies have documented the prognostic value of normal exercise Tl myocardial perfusion imaging in patients with angiographic coronary artery disease (CAD). However, data on exercise Tc-sestamibi myocardial single photon emission computed tomography (SPECT) are scant. Accordingly, the purpose of this study was to investigate the prognostic value of normal exercise Tc-sestamibi SPECT in patients with angiographic CAD.

METHODS

We retrospectively investigated 90 consecutive patients who had a normal exercise Tc-sestamibi myocardial SPECT but angiographic CAD. A group of 69 consecutive patients with both normal exercise Tc-sestamibi myocardial SPECT and coronary arteries were included as control.

RESULTS

During a mean follow-up of 50+/-19 months, a total of three hard cardiac events (non-fatal myocardial infarction) and seven soft cardiac events (late revascularization) were observed. The annual hard cardiac event rate between the two groups was not significantly different (0.6% vs. 0.3%, chi=0.47, P=NS), nevertheless the annual soft cardiac event rate was higher in patients with angiographic CAD (1.9% vs. 0, chi=5.74, P=0.02). Moreover, the annual hard cardiac events rate in patients with angiographic CAD who were treated medically was also not significantly different from that of the control group (0.8% vs. 0.3%, chi=0.77, P=NS). Among patients with angiographic CAD, the annual hard cardiac event rate was not statistically different between those treated medically and those who underwent revascularization (0.8% vs. 0, chi=0.53, P=NS).

CONCLUSIONS

Our data demonstrate that normal exercise Tc-sestamibi myocardial SPECT despite angiographic CAD suggests a low rate of cardiac death or non-fatal myocardial infarction but a relatively high rate of late revascularization during an intermediate term of follow-up.

Prognostic implications of a normal stress technetium-99m-tetrofosmin myocardial perfusion study in patients with a healed myocardial infarct and/or previous coronary revascularization

Previous studies have shown a good outcome for patients who present with normal findings on stress myocardial perfusion imaging. Currently, the prognostic implications of a normal study in patients who have a history of coronary artery disease (CAD) are not clear. This study investigated the long-term prognosis after a normal finding on stress technetium-99m (Tc-99m)-tetrofosmin single-photon emission computed tomography in patients with a history of CAD. The study included 147 consecutive patients with a history of CAD (previous myocardial infarction and/or myocardial revascularization), who underwent exercise bicycle or high-dose dobutamine-atropine stress Tc-99m-tetrofosmin single-photon emission computed tomography, and had normal perfusion results during stress and at rest. Follow-up was completed in all patients. During a follow-up of 6.5 +/- 1.9 years, 20 patients (14%) died, 10 (7%) of whom died due to cardiac causes, and 12 (8%) had a nonfatal myocardial infarction. Annual cardiac death rates were 0.5% during the first 3 years of follow-up and 1.3% in the subsequent 3 years. Independent predictors of cardiac death were male gender, rate-pressure product at rest, and rate-pressure product at peak stress. In conclusion, patients who have a history of CAD have a very low cardiac death rate during the 3 years after a normal finding on stress Tc-99m-tetrofosmin single-photon emission computed tomography. Repeated testing should be reconsidered 3 years after the initial evaluation and when a change in symptoms or clinical condition occurs.

Incremental prognostic value of combined perfusion and function assessment during myocardial gated SPECT in patients aged 75 years or older

BACKGROUND

Perfusion and functional data obtained during gated single photon emission computed tomography (SPECT) have proven prognostic value in the middle-aged patient population. The aim of this study was to investigate whether perfusion and functional cardiac gated SPECT data have prognostic value in patients aged 75 years or older.

METHODS AND RESULTS

We studied clinical and gated SPECT predictors of cardiac and all-cause death in 294 patients aged 75 years or older with known or suspected coronary artery disease who were referred for tetrofosmin cardiac gated SPECT imaging. Summed perfusion scores were calculated in a 17-segment model by use of commercially available software (4D-MSPECT). Left ventricular functional data were calculated by use of QGS gated SPECT software. The median age of the study population was 78 years (range, 75-91 years). There were 160 men (54%) and 134 women (46%). During a median follow-up of 25.9 months (range, 1.8-36 months), 47 patients (16%) died (27 cardiac deaths). In a multivariate Cox proportional hazards regression analysis, the summed rest score (chi2 gain = 8.0, P = .009), transient ischemic dilatation index (chi2 gain = 6.3, P = .012), and resting left ventricular ejection fraction (chi2 gain = 7.0, P = .030) were independent predictors of all-cause death. The summed rest score (chi2 gain = 8.2, P = .004) and resting end-systolic volume (chi2 gain = 13.7, P = .005) were independent predictors of cardiac death.

CONCLUSIONS

This study showed that gated SPECT left ventricular functional data assessed during myocardial gated SPECT provide independent and incremental information above clinical and perfusion SPECT data for the prediction of cardiac and all-cause death in patients aged 75 years or older referred for myocardial SPECT imaging.

Detection of chest pain of non-cardiac origin at the emergency room by a new non-invasive device avoiding unnecessary admission to hospital

Recent advances in the treatment of acute coronary syndromes has raised awareness that prompt presentation for chest pain may be life saving. Most patients presenting with chest discomfort have a non-ischaemic ECG on presentation, but are routinely admitted to hospital because of diagnostic uncertainty for occult MI or ischaemia. We tested a new non-invasive device that measures central aortic pressure changes (dP/dtejc): an accepted index of myocardial performance that could be added to the diagnostic triage of ischaemia in the ER avoiding unnecessary admissions. We followed 85 patients presenting at the ER with acute chest pain. In 72 patients, negative ECG and myocardial enzyme dynamics ruled out coronary origin during the first 24 h after admission. In 8 of the 72 patients, coronary catheterisation found normal coronary arteries. In this group, average dP/dtejc was 163 (range 92-232). In 35 patients in whom the new non-invasive cardiac performance index dP/dtejc was above a threshold of >150, acute MI was ruled out. In 13 patients, acute chest pain had coronary origin confirmed by ECG and/or positive enzymes. The average dP/dtejc in this group was 117 (range 61-149). The dP/dtejc values were found to be significantly higher in patients without acute MI (p<0.001). Preliminary findings suggest that nearly 40% of patients presenting with acute chest pain could be spared the risks and costs of unnecessary hospital admission and more invasive cardiac testing by simply adding a easy to use, immediately obtained, test to the diagnostic protocol, and using a threshold of dP/dtejc>150 to rule out heart attack.

[Positive exercise test and normal exercise myocardial perfusion SPECT. Clinical significance]

OBJECTIVE

To establish, in our area, the clinical significance of a normal exercise myocardial perfusion study, in patients with an ischemic response of the exercise test.

MATERIAL AND METHODS

A retrospective study was carried out in our Service for the last four years. We studied 45 patients (41 women and 4 men) with an ischemic response of the exercise test and normal myocardial perfusion SPECT, during a mean follow-up of 13,2 months. We considered the final clinical diagnosis according to clinical evolution, therapy outcome and coronary angiography results.

RESULTS

The presence of positive exercise test and normal SPECT was predominant in women (93.3%). In 35 patients (77.8%), the final diagnosis was chest pain of probable non-coronary origin (not secondary to coronary artery disease): 18 patients were diagnosed of hypertensive cardiomyopathy, 3 of valvulopathy, 2 of vasospastic angina, 1 of hypertrophic obstructive cardiomyopathy, 1 of microvascular angina, 1 of angina due to arrhythmia, and 9 patients diagnosed of atypical chest pain due to functional or non-cardiac origin. In 10 patients (22.2%), the final diagnosis was chest pain of probable coronary origin. We did not observe any major cardiac events (cardiac death and nonfatal myocardial infarction) during the follow-up period.

CONCLUSIONS

Patients with chest pain, positive exercise test and normal SPECT have an excellent prognosis within an intermediate follow-up period. 77.8% of patients were diagnosed of chest pain of non-coronary origin. The most common cause of non-coronary chest pain was hypertensive cardiomyopathy (51.4%), followed by functional or non-cardiac chest pain (28.6%).

New frontiers in risk stratification using stress myocardial perfusion single photon emission computed tomography

PURPOSE OF REVIEW

The purpose of this review is to review the recent published literature since 2002 for studies using stress myocardial perfusion single photon emission computed tomography for determination of the prognostic value of testing.

RECENT FINDINGS

A series of manuscripts dealing with myocardial perfusion single photon emission computed tomography have been published over the past 2 years that have altered a number of the most basic concepts defining risk stratification. These studies may have redefined the manner in which noninvasive stress imaging results will be interpreted and applied.

SUMMARY

Recent studies have expanded the understanding of how stress myocardial perfusion single photon emission computed tomography is helpful in the identification of risk, enhanced the means of identifying risk, and improved its use as a means to identify optimal posttest treatment.