Prognostic value of dobutamine stress echocardiography in patients with diabetes

OBJECTIVE: The aim of this study was to assess the incremental value of dobutamine stress echocardiography (DSE) for the risk stratification of diabetic patients who are unable to perform an adequate exercise stress test. Exercise capacity is frequently impaired in patients with diabetes. The role of pharmacologic stress echocardiography in the risk stratification of diabetic patients has not been well defined. RESEARCH DESIGN AND METHODS: We studied 396 diabetic patients (mean age 61 +/- 11 years, 252 men [64%]) with limited exercise capacity who underwent DSE for evaluation of known or suspected coronary artery disease (CAD). End points were hard cardiac events (cardiac death and nonfatal myocardial infarction) and all causes of mortality. RESULTS: During a median follow-up of 3 years, 97 patients (24%) died (55 cardiac deaths), and 27 patients had nonfatal myocardial infarction. In an incremental multivariate analysis model, clinical predictors of hard cardiac events were history of congestive heart failure, previous myocardial infarction, hypercholesterolemia, and ejection fraction at rest. The percentage of ischemic segments was incremental to the clinical model in the prediction of hard cardiac events (chi(2) = 37 vs. 18, P < 0.05). Clinical predictors of all causes of mortality were history of congestive heart failure, age, hypercholesterolemia, and ejection fraction at rest. Wall motion score index at peak stress was incremental to the clinical model in the prediction of mortality (chi(2) = 52 vs. 43, P < 0.05). CONCLUSIONS: DSE provides incremental data for the prediction of mortality and hard cardiac events in patients with diabetes who are unable to perform an adequate exercise stress test.     

Prognostic value of combined magnetic resonance myocardial perfusion imaging and late gadolinium enhancement

Late gadolinium enhancement (LGE) and myocardial perfusion study by cardiac magnetic resonance (CMR) have a diagnostic and prognostic value in patients with suspected coronary artery disease (CAD). The purpose of this study was to determine the prognostic value of combined myocardial perfusion CMR and LGE in patients with known or suspected CAD. We studied patients with known or suspected CAD. All patients underwent CMR for functional study, myocardial perfusion and LGE. Myocardial ischemia by CMR was defined as a perfusion defect in patients without LGE or a perfusion defect beyond the LGE area. Patients were followed up for cardiovascular outcomes including hard cardiac events (cardiac death or non-fatal myocardial infarction) and major adverse cardiac events (MACE) which included cardiac death, non-fatal myocardial infarction, hospitalization for unstable angina, and heart failure. There were a total of 587 men and 645 women. Average age was 64.6 ± 11.1 years. LGE was detected in 326 patients (26.5%). Myocardial ischemia by CMR was detected in 423 patients (34.3%). Average follow-up duration was 34.9 ± 15.6 months. Univariate analysis showed that age, diabetes, use of beta blocker, left ventricular ejection fraction, left ventricular mass, wall motion abnormality, LGE, and myocardial ischemia are predictors for hard cardiac events and MACE. Multivariable analysis revealed that myocardial ischemia was the strongest predictor for hard cardiac events and MACE. Other independent predictors were age, use of beta blocker, and left ventricular mass. Myocardial ischemia by CMR has an incremental prognostic value for cardiac events in patients with known or suspected CAD.     

Abnormal electron beam computed tomography results: the value of repeating myocardial perfusion single-photon emission computed tomography in the ongoing assessment of coronary artery disease

OBJECTIVE: To determine whether asymptomatic patients with atherosclerosis, indicated by the presence of coronary artery calcium on electron beam computed tomography, are at enough risk for progression of disease to justify a repeated stress single-photon emission computed tomography (SPECT) examination after an initial normal to low-risk perfusion study. PATIENTS AND METHODS: We retrospectively identified patients who had abnormal results on electron beam computed tomography (coronary artery calcium score > 0) and normal to low-risk results on SPECT (defined as a summed stress score of 0-3) within a 3-month period from January 1, 1995, to October 31, 2002. Of the 504 identified patients, 285 remained after exclusion criteria were applied. Of the 285 patients, 69 (mean +/- SD age, 58.2 +/- 7.6 years; 91% male) underwent at least 1 repeated myocardial perfusion SPECT imaging study within 4 years of their initial assessment as normal or at low risk without recurrence of symptoms. The value of repeated SPECT imaging was assessed by detection of a substantial change in the repeated SPECT study and by documentation of a clinical event (death, nonfatal myocardial infarction, or revascularization). Follow-up was 100% complete at a mean of 4.3 +/- 1.6 years. RESULTS: Only 4 patients (6%) had a substantial progression in their SPECT risk category; substantial changes on the SPECT scans occurred only in patients with a coronary artery calcium score greater than 100. Three patients underwent revascularization, yielding a 5-year rate for survival free of revascularization of 94% (95% confidence interval, 88%-100%). No deaths or nonfatal myocardial infarctions were reported. CONCLUSION: The principal findings of this study indicate that asymptomatic patients with initial normal or low-risk results from stress SPECT performed because of abnormal coronary artery calcium scores who remain asymptomatic are at low risk of death, myocardial infarction, or coronary revascularization. Three patients underwent revascularization by percutaneous coronary intervention despite the absence of symptoms. A substantial change in SPECT results (defined as progression from normal or low-risk summed stress score to intermediate- or high-risk summed stress score) affected 6% of patients and was not associated with any adverse hard events (nonfatal myocardial infarction or death).     

Body mass index and rest myocardial perfusion defect predicts cardiac death in patients with chronic heart failure

Gated single photon emission computed tomography (SPECT) myocardial perfusion imaging has proven to be invaluable not only in assessing myocardial perfusion, but also in providing functional and volumetric information. The aim of this study was to investigate the value of clinical variables and rest gated SPECT myocardial perfusion imaging for predicting cardiac death in patients with chronic heart failure (CHF). Seventy-three consecutive hospitalized patients with CHF (aged 50.7 ± 16.5 years, 60 men and 13 women; 25 ischemic CHF and 48 non-ischemic CHF) and left ventricular ejection fraction on echocardiography <40%, who underwent rest gated SPECT myocardial perfusion imaging, were followed up for this study. Univariate and multivariate analysis of clinical characteristics and gated SPECT parameters for prediction of cardiac death were performed. During the follow-up period (18.6 ± 8.5 months), 14 (19.2%) cardiac deaths occurred. Multivariate Cox analysis showed that body mass index (BMI, 23.3 ± 4.1 kg/m², hazard ratio = 0.85, P = 0.025) and summed rest score (SRS, 11.8 ± 11.5, hazard ratio = 1.05, P = 0.021) were predictive for cardiac death. The optimal threshold of BMI was 25 kg/m² and patients with BMI < 25 kg/m² had lower survival rate (P = 0.013). The optimal threshold of SRS was set as 11 and patients with SRS > 11 had lower survival rate (P = 0.009). Rest gated SPECT myocardial perfusion imaging provides prognostic information in patients with CHF. BMI and SRS are both predictors of cardiac death in patients with CHF.     

Prediction of cardiovascular events in clinically selected high-risk NIDDM patients. Prognostic value of exercise stress test and thallium-201 single-photon emission computed tomography.

OBJECTIVE: We evaluated the prognostic value of an exercise stress test and thallium-201 scintigraphy for the prediction of cardiac events in selected high-risk NIDDM patients. RESEARCH DESIGN AND METHODS: NIDDM patients (n = 158, 105 men, aged 63 +/- 9 years) with two or more of the following criteria were prospectively included: age > or = 65 years, active smoking, hypertension > 160/95 mmHg, hypercholesterolemia (cholesterol > 5.70 mmol/l or LDL > 3.10 mmol/l), peripheral artery disease, abnormal rest electrocardiogram, or microalbuminuria (20-200 micrograms/min). An exercise-stress scintigraphy was performed in 77 patients able to exercise, while a dipyridamole scintigraphy was performed in 80 patients unable to exercise. Follow-up was 23 +/- 17 months. Major end points were cardiac deaths or nonfatal myocardial infarction. RESULTS: The annual event rate was 7.31% (deaths: 8, myocardial infarction: 14). Independent predictors of events were as follows: an age > 60 (P = 0.02), an abnormal rest electrocardiogram (P = 0.02), microalbuminuria (P = 0.001), the inability to exercise (P = 0.009), and the presence of more than two defects on scintigraphy (P = 0.001). A cardiac death occurred in 1.3% of patients able to exercise versus 8.8% of patients unable to exercise (odds ratio = 6.8, P = 0.001). Among patients unable to exercise, large perfusion defects corresponded to an annual mortality rate of 22.3%. Conversely, the negative predictive value of a normal scintigraphy for the occurrence of death was 97%. CONCLUSIONS: Inability to exercise and large perfusion defects on thallium-201 scan are major predictors of future death and myocardial infarction in high-risk NIDDM patients.     

Gender-based prognostic value of pharmacological cardiac magnetic resonance stress testing: head-to-head comparison of adenosine perfusion and dobutamine wall motion imaging

This study evaluated the gender related long-term prognostic value of adenosine perfusion and dobutamine wall motion imaging as assessed during a combined single-session stress cardiac magnetic resonance (CMR) examination. In 717 patients a combined CMR stress examination was performed. Inducible perfusion deficits and wall motion abnormalities were identified visually. Clinical parameters were assessed at the time of the CMR examination. All patients were contacted to determine the occurrence of hard cardiac events (cardiac death, myocardial infarction) during a median follow-up period of 5.3 years. A complete combined CMR examination and follow-up data were available in 679 patients (471 men). A total of 77 hard cardiac events (63 in men) occurred during follow-up. Multivariate analysis revealed the presence of inducible perfusion deficits or wall motion abnormalities as independent predictors of hard cardiac events for both gender with an incremental value over conventional cardiovascular risk factors. In case of a negative stress test result, event-free survival was 100% in women for 4 years and >99% in men for 2 years after the CMR examination. CMR perfusion and wall motion testing are equally suited for cardiac risk stratification in men and women. Stress CMR negative women exhibited very low event rates up to 4 years following the examination, while in men annual event rates increased after the second year. Consequently, the generally proposed 2-year warranty period of non-invasive stress testing may be prolonged to a 4 year level in CMR stress testing negative women.     

Predictive value of silent myocardial ischemia for cardiac events in diabetic patients: influence of age in a French multicenter study

OBJECTIVE: Silent myocardial ischemia (SMI) in asymptomatic subjects with no history of myocardial infarction or angina is a frequent condition in diabetic patients. The aim of the study was to examine the predictive value of SMI for cardiac events in a multicenter cohort and to determine whether this value is higher in patients with a particular clinical profile. RESEARCH DESIGN AND METHODS: A total of 370 asymptomatic diabetic patients with at least two additional cardiovascular risk factors was recruited in four departments of diabetology. SMI was assessed by either exercise or dipyridamole single-photon emission-computed tomography myocardial perfusion imaging with thallium-201. If dipyridamole stress was used, an electrocardiogram stress test was performed separately on another day. Follow-up duration was 3-89 months (38 +/- 23 months). RESULTS: There was evidence of SMI in 131 patients (35.4%) on at least one positive noninvasive test. The patients with SMI were significantly older and had significantly higher serum triglycerides and lower HDL cholesterol levels. Cardiac events occurred in 53 patients (14.3%). Major cardiac events (death or myocardial infarction) occurred in 38 patients (10%) and other events (unstable angina, heart failure, or coronary revascularization) occurred in 15 patients. The patients who had cardiac events were older and had higher serum triglyceride levels at baseline. There was a significant association between SMI and cardiac events (hazard ratio 2.79 [95% CI 1.54-5.04]) and in particular major cardiac events (3 [1.53-5.87]). In the patients >60 years of age, the prevalence of SMI was higher (43.4 vs. 30.2% in those <60 years). SMI was associated with a significant risk of cardiac events (2.89 [1.31-6.39]) and in particular major cardiac events (3.66 [1.36-9.87]) for the patients >60 years old but not for those <60 years old. CONCLUSIONS: In asymptomatic diabetic patients with additional cardiovascular risk factors, SMI is a potent predictor of cardiac events and should be assessed preferably in the patients >60 years of age.     

Prognostic Interplay Between Coronary Artery Calcium Scoring and Cardiorespiratory FItness: The CAC-FIT Study

ObjectiveTo assess the incremental prognostic role of coronary artery calcium score (CACS) and exercise capacity (EC), two independent prognostic tests in the assessment of patients with coronary artery disease.MethodsThe cohort consisted of patients who had clinically indicated exercise stress testing and CACS assessment from January 1, 2015, to September 30, 2021, with a median of 27 days between each other. Exercise capacity was defined by peak metabolic equivalents of task (METs) achieved during exercise stress test. The CACS was determined by the Agatston method. Patients were observed from the latest test date to incident major adverse cardiac events (inclusive of all-cause death, nonfatal myocardial infarction, late revascularization, and admission for heart failure).ResultsThere were a` total of 1932 patients in the study population (mean age, 56±12 years; 42% female, 48% hypertension, 21% diabetes, 48% dyslipidemia). Peak METs below 6 was achieved in 8% of patients, and the median (interquartile range) CACS was 9 (0-203). In multivariable Cox regression models, both CACS (1 unit increase in log CACS: hazard ratio, 1.19; 95% CI, 1.06 to 1.34; P=.003;) and EC (1 unit increase in peak METs: hazard ratio, 0.89; 95% CI, 0.81 to 0.97; P=.01) were independently associated with outcomes. Using CACS+EC added incremental prognostic value over clinical and fitness models (C index increase from 0.68 to 0.75; P=.015). Incident event rates increased across categories of CACS and EC.ConclusionOur analysis found that CACS and EC have complementary risk-stratifying roles in coronary artery disease.     

Prognostic value of real time dobutamine stress myocardial contrast echocardiography in patients with chest pain syndrome

The aims of this study were (1) to evaluate the prognostic value of negative wall motion (WM) and myocardial perfusion during contrast-dobutamine stress echocardiography (DSE), (2) to determine whether WM-myocardial contrast echocardiography (MCE) had incremental prognostic value over just WM during DSE in patients with chest pain in the emergency room (ER), and (3) to compare the prognostic value of negative DSE-WM, and DSE-WM-MCE to nuclear-myocardial perfusion imaging (N-MPI) in a similar patient population over the same time period. We retrospectively studied 569 patients with real time contrast DSE, and 147 patients underwent N-MPI for evaluation of chest pain. Follow-up for cardiac events was obtained between 12 and 25 months. The cumulative cardiac event-free survival was 94.5% in negative DSE-WM, 97.1% in negative DSE-WM-MCE and 96.7% in negative N-MPI group. Cardiac event-free survival of the negative DSE-WM-MCE group was significantly higher than the DSE-WM group (log rank P < 0.01), and similar in the DSE-WM-MCE group compared to the N-MPI group. Combined WM and perfusion during DSE was the strongest independent predictor for cardiac events. The negative predictive power of DSE-WM-MCE is superior to that of just negative DSE-WM and is comparable to that of N-MPI. Myocardial perfusion and WM analysis during DSE provide independent information for predicting cardiac events in patients with chest pain syndrome in the ER.     

Stress radionuclide myocardial perfusion imaging detects more residual ischemia than stress echocardiography following acute myocardial infarction

OBJECTIVES: This investigation sought to compare the abilities of stress radionuclide myocardial perfusion imaging and stress echocardiography to detect residual ischemia in patients following acute myocardial infarction (MI). BACKGROUND: Stress radionuclide myocardial perfusion imaging and stress echocardiography are both commonly used to assess patients (patients.) in the immediate post MI period. However, the relative value of these techniques in identifying post MI ischemia remains unclear. METHODS: Eighteen patients. underwent both dipyridamole radionuclide perfusion imaging and dobutamine stress echocardiography on the same day or on consecutive days, 3-7 days following uncomplicated acute MI. Pts. who had an acute percutaneous intervention were excluded. Images were reviewed with clinical information available, but blinded to the opposing modality, for perfusion defects, wall motion abnormalities (WMA), and evidence of ischemia (reversible defect(s) on perfusion imaging, worsening WMA on stress echocardiography). Of the 18 patients, 11 subsequently underwent cardiac catheterization. RESULTS: Perfusion imaging identified defects in 16 (89%) patients, of whom 15 (83% of total) were found to be ischemic. Stress echocardiography identified a fixed wall motion abnormality in 17 (94%) and ischemia in 8 (44%, p < 0.05 compared with perfusion imaging ischemia). Among 11 patients who underwent catheterization, there was a trend towards perfusion imaging identifying more ischemia in the territory of an obstructed (> or = 70%) vessel--100% (11/11) vs. 64% (7/11) for stress echocardiography (p = 0.09). CONCLUSION: In the immediate post-infarction period, dipyridamole stress radionuclide myocardial perfusion imaging more often shows evidence of residual ischemia than dobutamine stress echocardiography.     

Role of Coronary Flow Velocity in Predicting Adverse Outcome in Clinical Practice

There is a lack of information on the prognostic value of local high velocity in coronary arteries during echocardiography. The aim of the study described here was to define the prognostic value of local velocity >70?cm/s in the left main, anterior or circumflex artery during echocardiography. There were 412 patients in the prospective study. Death, non-fatal myocardial infarction, acute pulmonary edema, acute coronary syndrome and revascularization were defined as major adverse cardiac events (MACEs). Over 10.5?mo, there were 207 patients with MACEs. Seventeen patients died, 10 had non-fatal acute cardiac events and 184 underwent revascularization. Deaths occurred in patients with high local velocity (6.4% vs. 0%, p?<0.009). Acute cardiac events occurred in 10% versus 0% (p?<0.003). MACEs were observed in 62% versus 0% (p?<0.0000001). Only maximal velocity was an independent prognostic predictor of death (odds ratio?=?1.02, 95% confidence interval: 1.01–1.03, p?<0.02) and MACEs (odds ratio?=?1.04, 95% confidence interval: 1.02–1.05, p?<0.0001). The success rate of coronary artery visualization for at least one segment was 91%.     

Prognostic value of nitrate enhanced Tc99m MIBI SPECT study in detecting viable myocardium in patients with coronary artery disease

Background: Assessing the viability in akinetic myocardium is vital for predicting functional recovery after therapeutic management in patients with chronic coronary artery disease (CAD) and depressed left ventricular (LV) function. The present study aimed to evaluate the efficacy of Tc99m MIBI SPECT enhanced with nitroglycerine infusion in detecting myocardial viability, as well as to asses the relationship between the myocardial viability and the subsequent treatment and outcome of patients. Methods and results: Sixty-seven consecutive patients with CAD and LV dysfunction (LV ejection fraction 36.6 ± 8.4%) underwent Tc99m MIBI imaging – at rest and during intravenous nitroglycerine infusion – for viability assessment. Fourteen patients were treated pharmacologically (Group I), and fifty-three (Group II) were submitted to coronary revascularization (PTCR or CABG). Fifteen major cardiac events were observed during 25 months of the follow-up. A significantly worse event-free survival was registered in the subjects of Group I than in Group II subjects. The prognostic predictors of cardiac events were: (1) the number of viable, non-revascularized segments in perfusion imaging (p < 0.001), (2) the severity of the disease assessed by coronary angiography (p < 0.05). Conclusions: Viability detection in nitroglycerine infusion enhanced Tc99m MIBI imaging offers significant prognostic value in patients with CAD after myocardial infarction. Patients with preserved viability showed better prognosis after revascularization than those treated pharmacologically.     

Dipyridamole stress echocardiography stratifies outcomes of asymptomatic patients with recent myocardial revascularization

Background Patients with previous myocardial revascularization, even if symptom-free, remain at risk of subsequent cardiac events, so that a non-invasive tool able to stratify this population is wishful. Objectives To assess the prognostic value of dipyridamole stress echocardiography (DipSE) in a population of asymptomatic patients following complete myocardial revascularization, either by coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI). Methods We retrospectively evaluated 104 consecutive symptom-free patients (mean age 67 ± 9.3 years, 75 males) with recent (<12 months) complete myocardial revascularization (48% PCI, 52% CABG) undergoing DipSE. Ischemia was defined as the onset of a new or worsening wall motion abnormality during DipSE. The composite end point of the study was cardiac death and non-fatal acute coronary syndrome. Results Myocardial ischemia was identified in 23 patients (22.1%). During a mean follow up of 21 months, 7 (30.4%) out of these patients suffered cardiac events. Among the remaining 81 patients (77.9%) with negative DipSE results, 7 (8.6%) experienced cardiac events. At multivariable analysis only a positive DipSE (odds ratio 3.9, P = 0.03), wall motion score index at peak of stress (OR 3.6, P = 0.04) and a prior myocardial infarction (odds ratio 3.5, P = 0.04) achieved statistical significance for cardiac events. Moreover, DipSE effectively stratified patients into a high and low risk group according to presence of inducible ischemia (event rate per year 16% vs 4.8%, P = 0.02). Conclusions DipSE yields appropriate risk stratification and provides incremental prognostic value over clinical variables even in asymptomatic patients with prior complete myocardial revascularization. A negative DipSE portends a benign prognosis (<5% event rate/year) in such population.     

Detection of silent myocardial ischemia in asymptomatic diabetic subjects: the DIAD study

OBJECTIVE: To assess the prevalence and clinical predictors of silent myocardial ischemia in asymptomatic patients with type 2 diabetes and to test the effectiveness of current American Diabetes Association screening guidelines. RESEARCH DESIGN AND METHODS: In the Detection of Ischemia in Asymptomatic Diabetics (DIAD) study, 1,123 patients with type 2 diabetes, aged 50-75 years, with no known or suspected coronary artery disease, were randomly assigned to either stress testing and 5-year clinical follow-up or to follow-up only. The prevalence of ischemia in 522 patients randomized to stress testing was assessed by adenosine technetium-99m sestamibi single-photon emission-computed tomography myocardial perfusion imaging. RESULTS: A total of 113 patients (22%) had silent ischemia, including 83 with regional myocardial perfusion abnormalities and 30 with normal perfusion but other abnormalities (i.e., adenosine-induced ST-segment depression, ventricular dilation, or rest ventricular dysfunction). Moderate or large perfusion defects were present in 33 patients. The strongest predictors for abnormal tests were abnormal Valsalva (odds ratio [OR] 5.6), male sex (2.5), and diabetes duration (5.2). Other traditional cardiac risk factors or inflammatory and prothrombotic markers were not predictive. Ischemic adenosine-induced ST-segment depression with normal perfusion (n = 21) was associated with women (OR 3.4). Selecting only patients who met American Diabetes Association guidelines would have failed to identify 41% of patients with silent ischemia. CONCLUSIONS: Silent myocardial ischemia occurs in greater than one in five asymptomatic patients with type 2 diabetes. Traditional and emerging cardiac risk factors were not associated with abnormal stress tests, although cardiac autonomic dysfunction was a strong predictor of ischemia.     

Value of absence of a transient myocardial perfusion defect during stress myocardial perfusion study in patients undergoing major vascular surgery

Pre-operative cardiac assessment is important in the evaluation of patients undergoing major vascular surgery. Our study aims to evaluate the value of absence of a transient myocardial perfusion defect during radionuclide myocardial perfusion study for prediction of cardiac events (myocardial infarction, sudden cardiac death, unstable angina, coronary artery revascularization and congestive heart failure) in patients undergoing major vascular surgery. We studied 63 consecutive patients (ages 35–83 [avg. 64], male 39, female 24) with radiographically proven, abdominal aortic aneurysm or severe aortofemoral occlusive disease who underwent major vascular surgery (abdominal aortic aneurysm repair [38] or aortofemoral bypass [25]). The subjects all had multiple coronary artery risk factors (hypertension 48, diabetes 10, hyperlipidemia 23, tobacco use 39, family history of coronary artery disease 10), but a negative pre-operative stress myocardial perfusion study for myocardial ischemia. Of these 63 patients, 17 patients were able to exercise and achieve their adequate 85% maximal predicted heart rate. Thirty-eight patients received adenosine infusion of 140 g/kg/min for 6 min. Six patients received dipyridamole infusion of 0.56 mg/kg over 4 min. Two patients received dobutamine infusion at 5, 10, 20, 30, and 40 mg/kg/min. Of the 63 patients, 60 received 3–4 mCi of thallium-201 (²⁰¹Tl) and 3 patients received 8–9 mCi of technetium-99^m (^99mTc) at rest and 25–30 mCi ^99mTc during stress. The subjects all underwent major vascular surgery and were followed up to one year for any cardiac events. Of the 63, who underwent pre-operative cardiac assessment with myocardial perfusion testing, 25 had a fixed myocardial perfusion defect (scar) and none had evidence of transient myocardial perfusion defect (ischemia). One subject had coronary artery bypass grafting 11 months after aortofemoral bypass surgery. One died from a stroke one month after aortofemoral bypass surgery. Of the remaining 61 patients, none had any cardiac events up to one year after major vascular surgery.     

Prognostic value of automated SPECT scoring system for coronary artery disease in stress myocardial perfusion and fatty acid metabolism imaging

Quantitative SPECT analysis contributes to the diagnostic and prognostic assessment of coronary artery disease. A novel automated scoring system (heart score view) can provide identical quantitative information to that determined by expert visual analysis. The aim of the present study is to evaluate the prognostic value of the automated SPECT scoring system when applied to stress thallium and resting beta-methyl-iodophenyl pentadecanoic acid (BMIPP) SPECT images. After a preliminary validation of the automated system by comparison with expert visual analyses, outcome data from 151 consecutive patients with suspected or known coronary artery disease without prior myocardial infarction were analyzed using automated SPECT scores on stress thallium and resting BMIPP images. The software quantified abnormalities as summed stress (SSS), summed rest and summed difference scores for stress thallium and as summed BMIPP scores (SBS). Cardiac events occurred over a period of 48 months in 29 (19.2 %) patients with diabetes mellitus, a lower left ventricular ejection fraction (LVEF) and more abnormal scores for thallium and BMIPP. Multivariate predictors of all cardiac events included diabetes mellitus and thallium SSS. The global Chi-square value was significantly increased when SSS was added to the clinical information (diabetes mellitus and LVEF). Negative predictive values of thallium SSS and SBS were almost identical at 84 % for all cardiac events and 98 % for hard cardiac events. Automatically quantified perfusion and BMIPP scores are related to cardiac events and these values can improve the risk stratification of coronary patients particularly when stress thallium imaging is combined with clinical information.     

The prognostic value of cardiac MRI

Although cardiac MRI (CMR) provides accurate quantitative assessment of myocardial function, structure, and tissue characterization, there is growing evidence of the prognostic significance of CMR in the clinical setting. This article aims to not only review the diagnostic utility of CMR but all the prognostic implications in different cardiac conditions. First, CMR can distinguish ischemic from nonischemic cardiomyopathies and is establishing an increasing role in risk stratifying patients with heart failure. Second, CMR perfusion with vasodilator and inotropic stress has high sensitivity and specificity for prediction of cardiovascular events. Third, in addition to being an accurate tool for assessing myocardial viability and predicting the benefits of coronary revascularization, scar characterization by CMR late gadolinium enhancement imaging provides prognostic information beyond traditional markers of left ventricular function and volume. This article aims to explore the current evidence of each of these clinical settings.     

Exercise echocardiography and thallium-201 single-photon emission computed tomography stress test for 5- and 10-year prognosis of mortality and specific cardiac events.

Limited data suggest that stress myocardial perfusion imaging and stress echocardiography have similar prognostic value for composite cardiac events. However, it is not known whether exercise echocardiography and stress thallium are similar in their prediction of specific cardiac events, eg, death, sudden death, myocardial infarction, unstable angina, and congestive heart failure. A total of 206 patients undergoing stress echocardiography and thallium-201 single-photon emission computed tomography imaging during the same exercise test were followed-up for 5 and 10 years. Multivariate Cox regression analyses incorporating clinical, exercise stress test, echocardiographic, and nuclear imaging parameters were used to predict mortality and specific cardiac events. A moderate to large amount of ischemia (> or =4 segments on the basis of a 16-segment model) by exercise stress echocardiography was the strongest predictor of overall mortality (relative risk [RR] 6.2; P <.0001), cardiac death (RR 17.6; P =.01), congestive heart failure (RR 17.4; P =.0005) or sudden death (RR 26.8; P =.003), whereas a moderate to large fixed defect (> or =2 segments on the basis of a 6-segment model) by nuclear imaging was the strongest predictor of myocardial infarction (RR 8.1; P =.0002) or unstable angina (RR 3.0; P =.005) at 5 years. The heterogeneity in the prediction of these specific cardiac events by these 2 modalities was similarly observed at 10 years. The extent of ischemia by stress echocardiography is a better predictor of overall mortality, cardiac death, congestive heart failure, or sudden death, whereas the extent of a fixed defect by nuclear imaging is a better predictor of myocardial infarction or unstable angina.     

Prognostic value of adenosine stress cardiovascular magnetic resonance in patients with low-risk chest pain

Background

Approximately 5% of patients with an acute coronary syndrome are discharged from the emergency room with an erroneous diagnosis of non-cardiac chest pain. Highly accurate non-invasive stress imaging is valuable for assessment of low-risk chest pain patients to prevent these errors. Adenosine stress cardiovascular magnetic resonance (AS-CMR) is an imaging modality with increasing application. The goal of this study was to evaluate the negative prognostic value of AS-CMR among low-risk acute chest pain patients.

Methods

We studied 103 patients, mean 56.7 ± 12.3 years of age, with chest pain and no electrocardiographic evidence of ischemia and negative cardiac biomarkers of necrosis, who were admitted to the Cardiac Decision Unit of our institution. All patients underwent AS-CMR. A negative AS-CMR was defined as absence of all the following: regional wall motion abnormalities at rest; perfusion defects during stress (adenosine) and rest; and myocardial scar on late gadolinium enhancement images. The patients were followed for a mean of 277 (range 161-462) days. The primary end point was defined as the combination of cardiac death, nonfatal acute myocardial infarction, re-hospitalization for chest pain, obstructive coronary artery disease (>50% coronary stenosis on invasive angiography) and coronary revascularization.

Results

In 14 patients (13.6%), AS-CMR was positive. The remaining 89 patients (86.4%), who had negative AS-CMR, were discharged. No patient with negative AS-CMR reached the primary end-point during follow-up. The negative predictive value of AS-CMR was 100%.

Conclusion

AS-CMR holds promise as a useful tool to rule out significant coronary artery disease in patients with low-risk chest pain. Patients with negative AS-CMR have an excellent short and mid-term prognosis.     

Coronary artery disease is common in nonuremic, asymptomatic type 1 diabetic islet transplant candidates

OBJECTIVE: Coronary artery disease (CAD) is the most common cause of death in patients with type 1 diabetes. Asymptomatic CAD is common in uremic diabetic patients, but its prevalence in nonuremic type 1 diabetic patients is unknown. The prevalence of CAD was determined by coronary angiography and the performance of noninvasive cardiac investigation evaluated in type 1 diabetic islet transplant (ITX) candidates with preserved renal function. RESEARCH DESIGN AND METHODS: A total of 60 consecutive type 1 diabetic ITX candidates (average age 46 years [mean 24-64], 23 men, and 47% ever smokers) underwent coronary angiography, electrocardiographic stress testing (EST), and myocardial perfusion imaging (MPI) in a prospective cohort study. CAD was indicated on angiography by the presence of stenoses >50%. Models to predict CAD were examined by logistic regression. RESULTS: Most subjects (53 of 60) had no history or symptoms of CAD; 23 (43%) of these asymptomatic subjects had stenoses >50%. CAD was associated with age, duration of diabetes, hypertension, and smoking. Although specific, EST and MPI were not sensitive as predictors of CAD on angiography (specificity 0.97 and 0.93, sensitivity 0.17 and 0.04, respectively) but helped identify two of three subjects requiring revascularization. EST and MPI did not enhance logistic regression models. A clinical algorithm to identify low-risk subjects who may not require angiography was highly sensitive but was applicable only to a minority (n = 8, sensitivity 1.0, specificity 0.27, negative predictive value 1.0). CONCLUSIONS: Nonuremic type 1 diabetic patients with hypoglycemic unawareness and/or metabolic lability referred for ITX are at high risk for asymptomatic CAD despite negative noninvasive investigations. Aggressive management of cardiovascular risk factors and further investigation into optimal cardiac risk stratification in type 1 diabetes are warranted.