Prognostic value of pharmacological stress echocardiography in patients with known or suspected coronary artery disease: a prospective, large-scale, multicenter, head-to-head comparison between dipyridamole and dobutamine test. Echo-Persantine International Cooperative (EPIC) and Echo-Dobutamine International Cooperative (EDIC) Study Groups

Machine learning to identify a composite indicator to predict cardiac death in ischemic heart disease

BACKGROUND

Machine learning (ML) employs algorithms that learn from data, building models with the potential to predict events by aggregating a large number of variables and assessing their complex interactions. The aim of this study is to assess ML potential in identifying patients with ischemic heart disease (IHD) at high risk of cardiac death (CD).

METHODS

3987 (mean age 68 ± 11) hospitalized IHD patients were enrolled. We implemented and compared various ML models and their combination into ensembles. Model output constitutes a new ML indicator to be employed for stratification. Primary variable importance was assessed with ablation tests.

RESULTS

An ensemble classifier combining three ML models achieved the best performance to predict CD (AUROC of 0.830, F1-macro of 0.726). ML indicator use through Cox survival analysis outperformed the 18 variables individually, producing a better stratification compared to standard multivariate analysis (improvement of ∼20%). Patients in the low risk group defined through ML indicator had a significantly higher survival (88.8% versus 29.1%). The main variables identified were Dyslipidemia, LVEF, Previous CABG, Diabetes, Previous Myocardial Infarction, Smoke, Documented resting or exertional ischemia, with an AUROC of 0.791 and an F1-score of 0.674, lower than that of 18 variables. Both code and clinical data are freely available with this article.

CONCLUSION

ML may allow a faster, low-cost and reliable evaluation of IHD patient prognosis by inclusion of more predictors and identification of those more significant, improving outcome prediction towards the development of precision medicine in this clinical field.

The Role of Non-Invasive Multimodality Imaging in Chronic Coronary Syndrome: Anatomical and Functional Pathways

Coronary artery disease (CAD) is one of the major causes of mortality and morbidity worldwide, with a high socioeconomic impact. Currently, various guidelines and recommendations have been published about chronic coronary syndromes (CCS). According to the recent European Society of Cardiology guidelines on chronic coronary syndrome, a multimodal imaging approach is strongly recommended in the evaluation of patients with suspected CAD. Today, in the current practice, non-invasive imaging methods can assess coronary anatomy through coronary computed tomography angiography (CCTA) and/or inducible myocardial ischemia through functional stress testing (stress echocardiography, cardiac magnetic resonance imaging, single photon emission computed tomography-SPECT, or positron emission tomography-PET). However, recent trials (ISCHEMIA and REVIVED) have cast doubt on the previous conception of the management of patients with CCS, and nowadays it is essential to understand the limitations and strengths of each imaging method and, specifically, when to choose a functional approach focused on the ischemia versus a coronary anatomy-based one. Finally, the concept of a pathophysiology-driven treatment of these patients emerged as an important goal of multimodal imaging, integrating 'anatomical' and 'functional' information. The present review aims to provide an overview of non-invasive imaging modalities for the comprehensive management of CCS patients.

Stress-echocardiography or coronary computed tomography in suspected chronic coronary syndrome after the 2019 European Guidelines? A practical guide

Stress-echocardiography can rightly be considered one of the champions of cardiac functional imaging, thanks to its real-time imaging, high temporal resolution, high safety and very low cost. When stress-echocardiography is performed at top technical quality, hence taking advantage of ultrasound contrast media for endocardial border delineation at least for suboptimal cases, subjectivity is minimized, and with the routine use of coronary flow reserve measurement (left anterior descending coronary artery, stress/rest ratio reduced or normal, i.e. <>2.0) diagnostic sensitivity is strengthened. The true competitor of any type of functional imaging, stress-echocardiography included, is nowadays coronary computed tomography angiography, which is instead a diagnostic method directly, noninvasively assessing coronary anatomy, apparently the holy grail for any cardiologist. The new 2019 Guidelines on chronic coronary syndrome of the European Society of Cardiology change the existing landscape and clinical practice, while they probably cannot clarify which type of test, functional or anatomic, should be first chosen in different clinical scenarios of suspected chronic coronary syndrome. We review the existing data and the authors' personal view in order to assess how functional stress-echocardiography compares with coronary computed tomography angiography regarding three main aspects: diagnosis of coronary artery disease, guidance of therapy (coronary revascularization versus medical therapy) and risk stratification.

Non-invasive Imaging in Coronary Syndromes - Recommendations of the European Association of Cardiovascular Imaging and the American Society of Echocardiography, in Collaboration with the American Society of Nuclear Cardiology, Society of Cardiovascular Computed Tomography and Society for Cardiovascular Magnetic Resonance

Coronary artery disease (CAD) is one of the major causes of mortality and morbidity worldwide, with a high socioeconomic impact.(1) Non-invasive imaging modalities play a fundamental role in the evaluation and management of patients with known or suspected CAD. Imaging end-points have served as surrogate markers in many observational studies and randomized clinical trials that evaluated the benefits of specific therapies for CAD.(2) A number of guidelines and recommendations have been published about coronary syndromes by cardiology societies and associations, but have not focused on the excellent opportunities with cardiac imaging. The recent European Society of Cardiology (ESC) 2019 guideline on chronic coronary syndromes (CCS) and 2020 guideline on acute coronary syndromes in patients presenting with non-ST-segment elevation (NSTE-ACS) highlight the importance of non-invasive imaging in the diagnosis, treatment, and risk assessment of the disease.(3)(4) The purpose of the current recommendations is to present the significant role of non-invasive imaging in coronary syndromes in more detail. These recommendations have been developed by the European Association of Cardiovascular Imaging (EACVI) and the American Society of Echocardiography (ASE), in collaboration with the American Society of Nuclear Cardiology, the Society of Cardiovascular Computed Tomography, and the Society for Cardiovascular Magnetic Resonance, all of which have approved the final document.

Apparent Declining Prognostic Value of a Negative Stress Echocardiography Based on Regional Wall Motion Abnormalities in Patients With Normal Resting Left Ventricular Function Due to the Changing Referral Profile of the Population Under Study

Background Cardiology guidelines identify the low-risk response during stress echocardiography as the absence of regional wall motion abnormalities. Methods From 1983 to 2016, we enrolled 5817 patients (age 63±12 years; 2830 males) with suspected coronary artery disease, normal regional, and global left ventricular function at rest and during stress (exercise in 692, dipyridamole in 4291, and dobutamine in 834). Based on timing of enrollment, 4 groups were identified in chronological order of recruitment: years 1983 to 1989, group 1 (n=211); years 1990 to 1999, group 2 (n=1491); years 2000 to 2009, group 3 (n=3285); and years 2010 to 2016, group 4 (n=830). Results There were 240 (4%) events (119 deaths and 121 infarctions) in the follow-up. At 1-year follow-up, the event rate was 0.5% (95% CI, 0.05-0.95), 1.5% (95% CI, -1.18 to 1.82), 1.9% (95% CI, 1.63-2.17), and 1.7% (95% CI, 1.01-2.39; χ², 9.0; P=0.03) in groups 1 to 4, respectively. At multivariable Cox analysis, independent predictors of future events were age (hazard ratio (HR), 1.05; 95% CI, 1.04-1.07; P<0.0001), male sex (HR, 1.57; 95% CI, 1.20-2.04; P=0.001), diabetes mellitus (HR, 1.78; 95% CI, 1.34-2.37; P<0.0001), smoking habit (HR, 1.40; 95% CI, 1.05-1.85; P=0.02), and ongoing anti-ischemic therapy (HR, 1.50; 95% CI, 1.15-1.97; P=0.003) Conclusions Over the past 3 decades, we observed a progressive decline in the prognostic value of a negative test based on regional wall motion abnormalities, likely reflecting both an increase in risk in patients, as well as a potential decrease in test performance due to concomitant anti-ischemic therapy.

[The Clinical use of Stress Echocardiography in Ischemic Heart Disease Cardiovascular Ultrasound (2017)15:7. Translation authors: Arystan A.Zh., Fettser D.V.]

Stress echocardiography is an established technique for the assessment of extent and severity of coronary artery disease. The combination of echocardiography with a physical, pharmacological or electrical stress allows detecting myocardial ischemia with an excellent accuracy. A transient worsening of regional function during stress is the hallmark of inducible ischemia. Stress echocardiography provides similar diagnostic and prognostic accuracy as radionuclide stress perfusion imaging or magnetic resonance, but at a substantially lower cost, without environmental impact, and with no biohazards for the patient and the physician. The evidence on its clinical impact has been collected over 35 years, based on solid experimental, pathophysiological, technological and clinical foundations. There is the need to implement the combination of wall motion and coronary flow reserve, assessed in the left anterior descending artery, into a single test. The improvement of technology and in imaging quality will make this approach more and more feasible. The future issues in stress echo will be the possibility of obtaining quantitative information translating the current qualitative assessment of regional wall motion into a number. The next challenge for stress echocardiography is to overcome its main weaknesses: dependence on operator expertise, the lack of outcome data (a widespread problem in clinical imaging) to document the improvement of patient outcomes. This paper summarizes the main indications for the clinical applications of stress echocardiography to ischemic heart disease.

The clinical use of stress echocardiography in ischemic heart disease

Stress echocardiography is an established technique for the assessment of extent and severity of coronary artery disease. The combination of echocardiography with a physical, pharmacological or electrical stress allows to detect myocardial ischemia with an excellent accuracy. A transient worsening of regional function during stress is the hallmark of inducible ischemia. Stress echocardiography provides similar diagnostic and prognostic accuracy as radionuclide stress perfusion imaging or magnetic resonance, but at a substantially lower cost, without environmental impact, and with no biohazards for the patient and the physician.

The evidence on its clinical impact has been collected over 35 years, based on solid experimental, pathophysiological, technological and clinical foundations. There is the need to implement the combination of wall motion and coronary flow reserve, assessed in the left anterior descending artery, into a single test. The improvement of technology and in imaging quality will make this approach more and more feasible. The future issues in stress echo will be the possibility of obtaining quantitative information translating the current qualitative assessment of regional wall motion into a number. The next challenge for stress echocardiography is to overcome its main weaknesses: dependance on operator expertise, the lack of outcome data (a widesperad problem in clinical imaging) to document the improvement of patient outcomes. This paper summarizes the main indications for the clinical applications of stress echocardiography to ischemic heart disease.

Prognostic value of dobutamine stress myocardial perfusion echocardiography in patients with known or suspected coronary artery disease and normal left ventricular function

Objective

We sought to determine the prognostic value of qualitative and quantitative analysis obtained by real-time myocardial perfusion echocardiography (RTMPE) in patients with known or suspected coronary artery disease (CAD).

Background

Quantification of myocardial blood flow reserve (MBFR) in patients with CAD using RTMPE has been demonstrated to further improve accuracy over the analysis of wall motion (WM) and qualitative analysis of myocardial perfusion (QMP).

Methods

From March 2003 to December 2008, we prospectively studied 168 patients with normal left ventricular function (LVF) who underwent dobutamine stress RTMPE. The replenishment velocity reserve (β) and MBFR were derived from RTMPE. Acute coronary events were: cardiac death, myocardial infarction and unstable angina with need for urgent coronary revascularization.

Results

During a median follow-up of 34 months (5 days to 6.9 years), 17 acute coronary events occurred. Abnormal β reserve in ≥2 coronary territories was the only independent predictor of events hazard ratio (HR) = 21, 95% CI = 4.5–99; p<0.001). Both, abnormal β reserve and MBFR added significant incremental value in predicting events over qualitative analysis of WM and MP (χ2 = 6.6 and χ2 = 24.6, respectively; p = 0.001 and χ2 = 6.6 and χ2 = 15.5, respectively; p = 0.012, respectively). When coronary angiographic data was added to the multivariate analysis model, β reserve remained the only predictor of events with HR of 21.0 (95% CI = 4.5–99); p<0.001.

Conclusion

Quantitative dobutamine stress RTMPE provides incremental prognostic information over clinical variables, qualitative analysis of WM and MP, and coronary angiography in predicting acute coronary events.

Usefulness of late gadolinium enhancement MRI combined with stress imaging in predictive significant coronary stenosis in new-diagnosed left ventricular dysfunction

BACKGROUND

To evaluate the accuracy of late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) and imaging stress test in predicting significant coronary artery disease (CAD) in left ventricular (LV) dysfunction.

METHODS

We enrolled 187 consecutive out-patients (61±17years) with new evidence of depressed (<45%) ejection fraction and no history of previous heart diseases and absence of Q-waves. All patients underwent coronary angiography (CA) and to LGE-CMR examination to identify ischemic and non-ischemic LGE. All patients underwent stress imaging to determine the presence of myocardial ischemia.

RESULTS

Ischemic-LGE was found in 83 patients and non-ischemic-LGE in 104. Significant CAD on CA was found in 86/187 patients. Ischemic-LGE showed a specificity of 94%, a sensitivity of 89% and an accuracy of 92% in identifying significant CAD. Imaging stress test was negative in 98/105 patients without CAD, and positive in 42/82 with significant CAD, showing a specificity of 93%, a sensitivity of 51% and an accuracy of 75% in identifying CAD. Combining CMR and stress test imaging, 94 patients had ischemic-LGE pattern and/or positive stress test for ischemia; of these 81/94 had significant CAD on CA and 13 had no CAD. Among the 93 patients with both tests negative, significant CAD was found in 5/93 patients. The combination of LGE and stress respect to only LGE did not improve the diagnostic accuracy (90 vs 92% respectively).

CONCLUSION

LGE-CMR had high accuracy in predicting significant CAD in ischemic LV dysfunction or as a bystander in non ischemic dysfunction.

Long-Term (>10 Years) Prognostic Value of Dobutamine Stress Echocardiography in a High-Risk Cohort

The prognostic value of dobutamine stress echocardiography (DSE) at >10-year follow-up is unknown. The aim of this study was to assess the very long-term prognostic value of DSE in a high-risk cohort of patients with known or suspected coronary artery disease. This prospective, single-center study included 3,381 patients who underwent DSE from January 1990 to January 2003. Two-dimensional echocardiographic images were acquired at rest, during dobutamine stress, and during recovery. Follow-up events were collected and included overall mortality, cardiac death, nonfatal myocardial infarction, and revascularization. The incremental value of DSE in the prediction of selected end points was evaluated using multivariate Cox proportional hazard analysis. During a mean follow-up of 13 ± 3.2 years (range 7.3 to 20.5 years), there were 1,725 deaths (51%), of which 1,128 (33%) were attributed to cardiac causes. Patients with an abnormal DSE had a higher mortality rate (44% vs 35% at 15-year follow-up, p <0.001) than those with a normal DSE. When comparing echocardiographic variables at rest to variables at maximum dose dobutamine, the chi-square of the test improved from 842 to 870 (p <0.0001) and from 684 to 740 (p <0.0001) for all-cause mortality and cardiac death, respectively. DSE provided incremental value in predicting all-cause mortality, cardiac death, and hard cardiac events. There seems, however, to be a "warranty period" of approximately 7 years, when the survival curves of a normal and abnormal DSE no longer diverge.

Feasibility, safety and accuracy of regadenoson-atropine (REGAT) stress echocardiography for the diagnosis of coronary artery disease: an angiographic correlative study

Regadenoson (REG), a selective A2A receptor vasodilator, has not been widely evaluated in stress echocardiography (SE). We report results of 45 patients participating in REG + atropine (REGAT) SE protocol conducted in a single-center prospective trial. The REGAT study enrolled subjects before a clinically indicated cardiac catheterization for suspected coronary artery disease (CAD). After rest imaging, a 2 mg Atropine (AT) bolus followed by 400 mcg of REG was given. Standard stress imaging views were obtained and interpreted in blinded fashion. Sensitivity, specificity, positive and negative predictive values (PPV, NPV) were calculated using cardiac catheterization >70 % stenosis as gold standard. Additional endpoints included major adverse cardiac events (MACE) and patient questionnaire responses. The mean duration of REGAT was 18 ± 7.2 min. There were no MACE, with only transient side-effects of dry mouth, shortness of breath, and headache. The incidence of significant CAD was 51.1 %. The sensitivity and specificity for significant stenosis was 60.9 and 86.4 %, with a PPV and NPV of 82.4 and 67.9 %. By coronary territories, the sensitivity, specificity, PPV, and NPV were: left anterior descending artery 58.8, 92.9, 83.3, and 78.8 %; left circumflex artery 6.7, 93.3, 33.3, and 67.7 %; and right coronary artery 16.7, 93.9, 50, and 75.6 %. Over 90 % of subjects reported feeling comfortable, with 83 % preferring REGAT as a future stress modality. The REGAT protocol is fast, safe, and well-tolerated with good specificity for CAD detection, but its low sensitivity and NPV precludes it from being an imaging modality for routine use.

Stress echocardiography

Stress echocardiography is the combination of 2D echocardiography with a physical, pharmacological or electrical stress. The diagnostic end point for the detection of myocardial ischemia is the induction of a transient worsening in regional function during stress. Stress echocardiography provides similar diagnostic and prognostic accuracy as radionuclide stress perfusion imaging but at a substantially lower cost, without environmental impact and with no biohazards for the patient and the physician. In spite of its dependence upon operator's training, it is the best possible choice to achieve the still elusive target of sustainable cardiac imaging in the field of noninvasive diagnosis of coronary artery disease.

A phase I study on pharmacokinetics and pharmacodynamics of higenamine in healthy Chinese subjects

AIM

To investigate the pharmacokinetics, pharmacodynamics, and safety of higenamine, an active ingredient of Aconite root, in healthy Chinese volunteers.

METHODS

Ten subjects received continuous, intravenous infusion of higenamine at gradually escalating doses from 0.5 to 4.0 μg·kg(-1)·min(-1), each dose was given for 3 min. Blood and urine samples were collected at designated time points to measure the concentrations of higenamine. Pharmacodynamics was assessed by measuring the subject's heart rate. A nonlinear mixed-effect modeling approach, using the software Phoenix NLME, was used to model the plasma concentration-time profiles and heart rate.

RESULTS

Peak concentrations (C(max)) of higenamine ranged from 15.1 to 44.0 ng/mL. The half-life of higenamine was 0.133 h (range, 0.107-0.166 h), while the area under concentration-time curve (AUC), extrapolated to infinity, was 5.39 ng·h·mL(-1) (range, 3.2-6.8 ng·h·mL(-1)). The volume of distribution (V) was 48 L (range, 30.8-80.6 L). The total clearance (CL) was 249 L/h (range, 199-336 L/h). Within 8 h, 9.3% (range, 4.6%-12.4%) of higenamine was recovered in the urine. The pharmacokinetics of higenamine was successfully described using a two-compartment model with nonlinear clearance. In the pharmacodynamic model, heart rates were related to the plasma drug concentrations using a simple direct effect model with baseline. The E(0), E(max), and EC(50) were 68 bpm, 73 bpm and 8.1 μg/L, respectively.

CONCLUSION

Higenamine has desirable pharmacokinetic and pharmacodynamic characteristics. The results provide important information for future clinical studies on higenamine.

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.

Imaging techniques in coronary atherosclerotic disease: dobutamine stress echocardiography--evidence and perspectives

Dobutamine stress echocardiography is the most widely disseminated noninvasive technique for the assessment of coronary artery disease. Its results are important for clinical decisions. It is a versatile technique with high sensitivity and specificity for detecting viable myocardium at jeopardy. More recently, strain rate imaging has been applied to stress echocardiography. This approach relies on tissue Doppler or two-dimensional strain imaging to quantify myocardial deformation. The application of contrast echocardiographic techniques to stress echocardiography enables left ventricular opacification for border enhancement and myocardial perfusion imaging. Thus, this application is not limited to stress echocardiography, but has utility whenever image quality adversely affects wall motion assessment. Recently, three-dimensional stress echocardiography imaging has been proposed as an alternative approach to assess myocardial ischemia.

Dipyridamole stress echocardiography in diagnosis and prognosis of hemodialysis patients with asymptomatic coronary disease

The prevalence of coronary artery disease (CAD) is high in hemodialysis (HD) patients. The aim of the study was to assess the diagnostic and prognostic value of dipyridamole stress echocardiography (DSE) in nondiabetic HD patients without signs or symptoms of CAD. In 51 out of 158 evaluated HD patients (21 females, age 67 [33-85] years, HD duration 38 [9-271] months), resting echocardiography and DSE were performed. Exclusion criteria were known CAD, diabetes mellitus, and pulmonary and oncologic pathologies. Logistic regression analysis was carried out to identify predictors of abnormal DSE response, while Cox regression analysis was performed to determine variables associated with total and cardiovascular mortality, after 43.3 (11-60) months of follow-up. Seven patients (14%) showed a positive response to DSE (DSE+). In 5/7, CAD was documented by angiography: All of them underwent coronary revascularization. DSE+ patients had significantly smaller body mass index than patients with a negative response (DSE-): 21.7 ± 1.9 vs. 25.1 ± 3.4 kg/m(2) (p = 0.018). During follow-up, 16 (31%) patients died. Older age hazard ratio [HR = 1.07; confidence interval (CI) = 1.01-1.12; p = 0.02] and higher plasma phosphate levels (HR = 10.41; CI = 2.30-47.17; p < 0.01) were predictors of total mortality. Male gender (HR = 22.7; CI = 1.45-354.4; p = 0.03), older age (HR = 1.24; CI = 1.03-1.50; p = 0.02), longer HD duration (HR = 1.13; CI = 1.01-1.26; p = 0.04), and positive response to DSE (HR = 5.82; CI = 1.04-32.65; p = 0.04) were associated with cardiovascular mortality. Ten percent of asymptomatic HD patients had significant CAD, but timely diagnosis did not seem to improve their prognosis. Total survival was associated with age and higher levels of plasma phosphate, while male gender, older age, longer HD duration, and DSE+ were predictors of cardiovascular mortality.

Prognostic effect of coronary flow reserve in women versus men with chest pain syndrome and normal dipyridamole stress echocardiography

The aim of this study was to investigate the prognostic effect of coronary flow reserve (CFR) on left anterior descending artery (LAD) in women and men with chest pain of unknown origin and normal stress echocardiogram. The study population consisted of 1,660 patients (906 women, 754 men) with chest pain syndrome, no wall motion abnormality on echocardiogram at rest, and dipyridamole (up to 0.84 mg/kg over 6 minutes) stress echocardiogram negative for wall motion criteria. All had undergone stress echocardiography with combined evaluation of CFR on LAD by Doppler. A CFR value ≤2.0 was considered abnormal. Median duration of follow-up was 19 months (interquartile range 10 to 34). Abnormal CFR was assessed in 171 women (19%) and 147 men (19%, p = 0.80). During follow-up, 80 events (20 deaths, 13 ST-elevation myocardial infarctions, and 47 non-ST-elevation myocardial infarctions) occurred. In addition, 128 patients underwent revascularization and were censored. CFR ≤2.0 on LAD was independently associated with prognosis in women (hazard ratio [HR] 16.48, 95% confidence interval [CI] 7.17 to 37.85, p <0.0001) and in men (HR 6.23, 95% CI 3.42 to 11.33, p <0.0001). Antianginal therapy at time of testing (HR 2.11, 95% CI 1.14 to 3.90, p = 0.02) was also a multivariable prognostic predictor in men. Four-year event rate associated with CFR values ≤2.0 and >2.0 were, respectively, 27% and 2% in women (p <0.0001) and 42% and 8% in men (p <0.0001). In conclusion, decreased CFR on LAD is associated with markedly increased risk in women and men with chest pain syndrome and a normal result of dipyridamole stress echocardiography. Conversely, preserved CFR on LAD predicts excellent survival, particularly in women.

Prognostic value of treadmill exercise and dobutamine stress positron emission tomography

BACKGROUND

Although positron emission tomography (PET) is routinely performed using vasodilator stress, exercise and dobutamine stress are available alternatives. Evidence suggests that vasodilator PET myocardial perfusion imaging (MPI) has prognostic value, but the prognostic value of treadmill exercise and dobutamine PET MPI is unknown.

OBJECTIVE

To determine the potential prognostic value of nonvasodilator stress PET MPI.

METHODS

Patients underwent treadmill exercise or dobutamine PET MPI. Images were assessed qualitatively and semiquantitatively. PET results were categorized as normal (summed stress score [SSS] of less than 4), abnormal (SSS of 4 or greater) or inconclusive (SSS of less than 4 and submaximal peak stress heart rate). Patient follow-up (cardiac death, nonfatal myocardial infarction [MI] and/or late revascularization) was performed.

RESULTS

Of the 124 patients (mean follow-up period of 2.3+/-1.6 years), 46 patients (37%) had a normal study, 15 patients (12%) had an inconclusive study and 63 (51%) had an abnormal PET. Patients with a normal PET had no deaths or nonfatal MI. One patient with a normal PET underwent late revascularization (annual event rate of 1.7%). Patients with an abnormal PET had 15 cardiac events (one cardiac death, four nonfatal MIs and 10 late revascularizations), with an annual event rate of 13.0% (P=0.002).

CONCLUSIONS

Although small, the present study suggests that defects seen on PET myocardial perfusion, resulting from stressors (treadmill exercise and dobutamine) that increase myocardial oxygen demand, may have prognostic value.

Stress/Rest Myocardial Perfusion Abnormalities by Gated SPECT: Still the Best Predictor of Cardiac Events in Stable Ischemic Heart Disease

The prognostic power of myocardial perfusion imaging in patients with ischemic heart disease (IHD) has been demonstrated since planar imaging. We aimed to investigate whether gated SPECT retains this value in current cardiology if compared with a complete diagnostic work-up and with more recent prognostic indicators.

METHODS

We selected from our database a cohort of 676 consecutive inpatients who underwent a complete diagnostic work-up that included gated SPECT and coronary arteriography for known or suspected IHD. Patients with acute myocardial infarction (MI), previous coronary artery bypass surgery, or overt hyperthyroidism and patients who were undergoing dialysis treatment were excluded. During follow-up (median, 37 mo), 24 patients died from cardiac causes and 19 experienced a nonfatal MI.

RESULTS

The following were determined to be independent predictors of event-free survival (cardiac death and nonfatal MI) in the different phases of diagnostic work-up using Cox proportional hazards regression analysis: among clinical variables, a previous MI; among laboratory examinations, serum creatinine and low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol levels; among electrocardiographic and echocardiographic variables, left ventricular ejection fraction; and among SPECT variables, summed rest score (SRS) and summed difference score (SDS). In addition, a score of coronary stenoses at angiography was an independent predictor. When the above predictors were tested together, SRS (P < 0.0001), SDS (P = 0.0108), and serum creatinine (P = 0.0186) and LDL and HDL cholesterol levels (P = 0.0222) were the final independent predictors of event-free survival. When gated SPECT was added to the clinical, laboratory, electrocardiographic, and echocardiographic variables, the prognostic stratification significantly improved (P < 0.05); when coronary arteriography was added to gated SPECT, prognostic stratification did not further improve (P > 0.25). If the information provided by gated SPECT was made available after clinical, laboratory, electrocardiographic, echocardiographic, and angiographic variables, the prognostic stratification still improved significantly (P < 0.05). In 492 of these patients with ascertained IHD, SRS and SDS were the final independent predictors of survival. Medical treatment and coronary revascularization did not affect the prognostic information of gated SPECT.

CONCLUSION

Myocardial perfusion abnormalities at rest and after stress are still the best predictors of cardiac event-free survival in patients with known or suspected IHD, even when compared with an extensive diagnostic work-up.

Impact of gender on risk stratification by stress echocardiography

OBJECTIVE

To compare the prognostic value of stress echocardiography results in men and women with known and suspected coronary artery disease.

METHODS

We analyzed the data of 8737 patients (5529 men and 3208 women) who underwent stress echocardiography (exercise in 523 patients, dipyridamole in 6227 patients, dobutamine in 1987) for evaluating known (n=3857) or suspected (n=4880) coronary artery disease. Patients were followed up for the occurrence of overall mortality or nonfatal myocardial infarction.

RESULTS

During a median follow-up of 25 months, 1218 cardiac events (693 deaths and 525 infarctions) occurred. Moreover, 2263 patients (1731 men [31%] and 532 women [17%]; P<.0001) underwent coronary revascularization and were censored. Stress echocardiography results added prognostic information to that of clinical findings and resting wall motion score index in men and women with both known and suspected coronary artery disease. In patients with known coronary artery disease, women had a higher (P=.01) event rate than men in the presence of ischemia. The annual event rate was worse for nondiabetic women (P=.007) but not diabetic women; age had a neutral prognostic effect in the 2 sexes. In patients with suspected coronary artery disease, men without ischemia had a higher (P<.0001) event rate than women. The annual event rate was worse in men aged less than 65 years (P<.0001) or more than 65 years (P=.04), and those with (P=.03) or without (P<.0001) diabetes.

CONCLUSION

Prognosis is at least comparable in men and women with ischemia and in those with coronary artery disease and no ischemia at stress echocardiography. In these clinical settings, availability for major procedures should be similar for both genders.

Prognostic value of dobutamine stress echocardiography with early injection of atropine with versus without chronic beta-blocker therapy in patients with known or suspected coronary heart disease

Although a new protocol of dobutamine stress echocardiography with the early injection of atropine (EA-DSE) has been demonstrated to be useful in reducing adverse effects and increasing the number of effective tests and to have similar accuracy for detecting coronary artery disease (CAD) compared with conventional protocols, no data exist regarding its ability to predict long-term events. The aim of this study was to determine the prognostic value of EA-DSE and the effects of the long-term use of beta blockers on it. A retrospective evaluation of 844 patients who underwent EA-DSE for known or suspected CAD was performed; 309 (37%) were receiving beta blockers. During a median follow-up period of 24 months, 102 events (12%) occurred. On univariate analysis, predictors of events were the ejection fraction (p <0.001), male gender (p <0.001), previous myocardial infarction (p <0.001), angiotensin-converting enzyme inhibitor therapy (p = 0.021), calcium channel blocker therapy (p = 0.034), and abnormal results on EA-DSE (p <0.001). On multivariate analysis, the independent predictors of events were male gender (relative risk [RR] 1.78, 95% confidence interval [CI] 1.13 to 2.81, p = 0.013) and abnormal results on EA-DSE (RR 4.45, 95% CI 2.84 to 7.01, p <0.0001). Normal results on EA-DSE with beta blockers were associated with a nonsignificant higher incidence of events than normal results on EA-DSE without beta blockers (RR 1.29, 95% CI 0.58 to 2.87, p = 0.54). Abnormal results on EA-DSE with beta blockers had an RR of 4.97 (95% CI 2.79 to 8.87, p <0.001) compared with normal results, while abnormal results on EA-DSE without beta blockers had an RR of 5.96 (95% CI 3.41 to 10.44, p <0.001) for events, with no difference between groups (p = 0.36). In conclusion, the detection of fixed or inducible wall motion abnormalities during EA-DSE was an independent predictor of long-term events in patients with known or suspected CAD. The prognostic value of EA-DSE was not affected by the long-term use of beta blockers.

Usefulness of stress echocardiography for risk stratification of patients after percutaneous coronary intervention

The prognostic value of stress echocardiography in patients with previous percutaneous coronary intervention (PCI) remains undefined. The aim of this study was to investigate the prognostic implication of stress echocardiography after PCI. The study group comprised 1,063 patients (794 men, 65 +/- 10 years of age) who underwent stress echocardiography with exercise (n = 105), dipyridamole (n = 780), or dobutamine (n = 178) after a median of 10 months from a successful PCI. Of these patients, 616 (58%) complained of chest pain and 447 (42%) were asymptomatic. Stress echocardiogram was positive for inducible ischemia in 328 patients (31%). During a median follow-up of 20 months, there were 167 events (61 deaths, 106 infarctions). Independent predictors of mortality were age (hazard ratio [HR] 1.06, 95% confidence interval [CI] 1.03 to 1.09, p <0.0001), wall motion score index at rest (HR 3.91, 95% CI 2.19 to 6.99, p <0.0001), and ischemia at stress echocardiography (HR 1.82, 95% CI 1.05 to 3.16, p = 0.03). Five-year mortalities were 20% in patients with and 9% in those without ischemia (p = 0.006). Independent predictors of hard events were ischemia at stress echocardiography (HR 3.82, 95% CI 2.75 to 5.29, p <0.0001), age (HR 1.02, 95% CI 1.01 to 1.04, p = 0.009), wall motion score index at rest (HR 1.98, 95% CI 1.30 to 3.02, p = 0.002), multivessel disease at time of PCI (HR 1.45, 95% CI 1.05 to 2.02, p = 0.02), and female gender (HR 1.44, 95% CI 1.03 to 2.01, p = 0.03). Five-year hard event rates were 53% in patients with and 16% in those without ischemia (p <0.0001). Stress echocardiographic positivity added prognostic information to clinical and at-rest echocardiographic parameters in symptomatic and asymptomatic patients. Moreover, it identified a subset of patients at higher risk of developing hard events independent of the subtending coronary anatomy (multivessel or single vessel disease). In conclusion, stress echocardiography is effective in risk-stratifying patients with previous PCI. In particular, inducible ischemia is a strong and independent predictor of mortality and hard events.

Subclinical impairment of coronary flow velocity reserve assessed by transthoracic echocardiography in young renal transplant recipients

BACKGROUND

In renal transplant recipients (RTR) an increased risk to develop cardiovascular injury is present. Transthoracic Doppler echocardiographic assessment of coronary flow velocity reserve (CFVR), a sensitive and minimally invasive technique, was recently employed to detect both macrovascular and microvascular coronary artery disease (CAD) in different clinical settings. The prevalence of coronary involvement in young adult RTR is still unknown. The aim of the study was to investigate the presence of early cardiovascular damage in asymptomatic young adult RTR.

METHODS

Transthoracic Doppler echocardiographic-derived CFVR and common carotid intima-media thickness (IMT) were assessed in 25 asymptomatic young adult RTR (mean age 25.7+/-7.0 years; range 17.3-43.9) without CAD and 25 healthy controls.

RESULTS

CFVR was lower in young adult RTR compared to controls (2.8+/-0.6 vs. 3.5+/-0.8; P<0.001), meanwhile left ventricular wall motion and common carotid IMT were comparable in both groups. We found a negative correlation between CFVR and age (r=-0.50; P=0.018) and months on dialysis (r=-0.54; P<0.01).

CONCLUSIONS

Young adult RTR showed a reduced CFVR reflecting an impaired coronary microcirculation, which is significantly related to the age and duration of dialysis; coronary microvascular damage is detectable in the absence of changes in common carotid IMT. Non-invasive evaluation of CFVR by transthoracic stress echocardiography could be a reliable method for identification of early coronary microvascular involvement in young adult RTR.

Additive prognostic value of interleukin-6 at peak phase of dobutamine stress echocardiography in patients with coronary artery disease. A 6-year follow-up study

BACKGROUND

Interleukin-6 (IL-6) and tissue factor (TF) are elevated after myocardial ischemia during dobutamine stress echo (DSE). We examined the incremental prognostic value of IL-6 or TF measured during DSE over echocardiographic and clinical factors in patients with chronic coronary artery disease (CAD).

METHODS

We studied 106 patients with angiographically documented CAD. IL-6 and TF were measured at rest, peak, and during recovery. A wall motion score index was calculated.

RESULTS

Fifty-seven (54%) patients had ischemia at DSE. During follow-up (63.7 +/- 20 months), 36 patients (33%) had an adverse event (12 cardiac deaths, 24 acute coronary events). Patients with events had a higher peak IL-6 (P = .02) but similar rest and recovery IL-6 than those without. Patients with peak IL-6 > or =3.14 pg/mL (upper tertile) had a hazard ratio of 2.7 (95% CI 1.44-5.37) (P < .01 for an adverse event). The addition of peak wall motion score index in a multivariable model including risk factors, ejection fraction, revascularization, and multivessel disease increased the model's c statistic from 0.66 to 0.70 (P = .04). The addition of peak IL-6 further increased the model's c statistic to 0.75 (P = .04). Tissue factor was not related with cardiac events.

CONCLUSIONS

Interleuikin-6 levels measured during the peak phase of DSE incrementally contribute to risk stratification in patients with chronic CAD.

The diagnostic accuracy of pharmacological stress echocardiography for the assessment of coronary artery disease: a meta-analysis

BACKGROUND

Recent American Heart Association/American College of Cardiology guidelines state that "dobutamine stress echo has substantially higher sensitivity than vasodilator stress echo for detection of coronary artery stenosis" while the European Society of Cardiology guidelines and the European Association of Echocardiography recommendations conclude that "the two tests have very similar applications". Who is right?

AIM

To evaluate the diagnostic accuracy of dobutamine versus dipyridamole stress echocardiography through an evidence-based approach.

METHODS

From PubMed search, we identified all papers with coronary angiographic verification and head-to-head comparison of dobutamine stress echo (40 mcg/kg/min +/- atropine) versus dipyridamole stress echo performed with state-of-the art protocols (either 0.84 mg/kg in 10' plus atropine, or 0.84 mg/kg in 6' without atropine). A total of 5 papers have been found. Pooled weight meta-analysis was performed.

RESULTS

the 5 analyzed papers recruited 435 patients, 299 with and 136 without angiographically assessed coronary artery disease (quantitatively assessed stenosis > 50%). Dipyridamole and dobutamine showed similar accuracy (87%, 95% confidence intervals, CI, 83-90, vs. 84%, CI, 80-88, p = 0.48), sensitivity (85%, CI 80-89, vs. 86%, CI 78-91, p = 0.81) and specificity (89%, CI 82-94 vs. 86%, CI 75-89, p = 0.15).

CONCLUSION

When state-of-the art protocols are considered, dipyridamole and dobutamine stress echo have similar accuracy, specificity and - most importantly - sensitivity for detection of CAD. European recommendations concluding that "dobutamine and vasodilators (at appropriately high doses) are equally potent ischemic stressors for inducing wall motion abnormalities in presence of a critical coronary artery stenosis" are evidence-based.

Cardiac functional stress imaging: a sequential approach with stress echo and cardiovascular magnetic resonance

AIMS

The aim of the study was to assess the feasibility and accuracy of an integrated stress imaging algorithm with echo first and second-line Cardiac Magnetic Resonance (CMR) in selected cases. Stress echo (SE) is widely used for non-invasive diagnosis of coronary artery disease (CAD), but difficult patients and ambiguous responses may be met even with top-level technology and expertise. CMR might ideally complement SE in well-selected cases with unfeasible and/or ambiguous and/or submaximal results.

METHODS AND RESULTS

152 in-hospital patients with chest pain and normal baseline function were referred for SE and coronary angiography. Of the initial population, 33 were shunted to CMR due to poor acoustic window or ambiguous or submaximal SE test. The only criterion of positivity for both techniques was the presence of regional wall motion abnormalities in at least 2 contiguous segments. Coronary angiography was performed independently of test results. Significant CAD was identified by a >50% quantitatively assessed diameter reduction in at least 1 major coronary vessel.CAD was present in 88 patients. Interpretable and diagnostic stress test were obtained in 143 patients with the sequential algorithm. The sequential (SE in 110 + CMR in 33 patients) algorithm showed a sensitivity of 76% (95% CI 66% to 85%) specificity of 87% (95% CI 76% to 95%) and accuracy of 80% (95% CI 73% to 86%).

CONCLUSION

A sequential functional stress imaging algorithm with stress echo first and stress CMR in selected cases is feasible, clinically realistic and allows an efficient, radiation-free diagnosis of CAD.

Effects of gender on prognosis of patients with known or suspected coronary artery disease undergoing contrast-enhanced dobutamine stress echocardiography

BACKGROUND

Gender differences in the predictors of outcome among patients with known or suspected coronary artery disease (CAD) undergoing contrast-enhanced dobutamine stress echocardiography (CE-DSE) have not been completely determined.

METHODS AND RESULTS

Follow-up (30+/-17 months) data for 581 men and 309 women with known or suspected CAD who underwent CE-DSE (mean age: 66 years) were obtained. Hard cardiac events included cardiac death and nonfatal myocardial infarction. Total cardiac events included hard cardiac events, unstable angina, congestive heart failure, and late revascularization (>3 months). Cardiac events occurred in 123 male and 50 female patients. Positive results for CE-DSE were associated with worse prognosis in both men and women (2-year total event free rate: 73.5% vs 88.2% in men, p<0.0001, 80.3% vs 91.3% in women, p<0.01). Addition of CE-DSE results, including abnormal left ventricular end-systolic volume response and left ventricular ejection fraction at peak stress <50%, to the clinical and rest echocardiography model provided incremental information for predicting total cardiac events (increase in chi-square value for the model from 60 to 72, p<0.001) in men and (increase in chi-square value for the model from 17 to 32, p<0.001) in women.

CONCLUSIONS

CE-DSE provides incremental information for predicting future cardiac events in both men and women.

Prognostic implications of dipyridamole or dobutamine stress echocardiography for evaluation of patients > or =65 years of age with known or suspected coronary heart disease

This study investigated the value of pharmacologic stress echocardiography for risk stratification of patients > or =65 years of age. The study cohort consisted of 2,160 patients > or =65 years of age (1,257 men, mean +/- SD 71 +/- 5 years of age) undergoing dipyridamole (n = 1,521) or dobutamine (n = 639) stress echocardiography for evaluation of known (n = 913) or suspected (n = 1,247) coronary artery disease. Of 2,160 patients, 753 (35%) had a normal test result, whereas 772 (36%) showed a myocardial ischemic pattern and 635 (29%) a scar pattern. During a median follow-up of 26 months, 241 deaths and 87 nonfatal myocardial infarctions occurred. Patients (n = 568) undergoing revascularization were censored. Of 16 analyzed variables, age (hazard ratio [HR] 1.07 per unit increment), wall motion score index at rest (HR 2.63 per unit increment), ischemia at stress echocardiography (HR 1.81), and diabetes (HR 1.57) were multivariable predictors of death, whereas age (HR 1.06 per unit increment), ischemia at stress echocardiography (HR 2.60), wall motion score index at rest (HR 1.98 per unit increment), scar pattern (HR 1.99), and diabetes (HR 1.48) were multivariable predictors of death or myocardial infarction. Using an interactive stepwise procedure, stress echocardiography showed incremental prognostic value over clinical and echocardiographic data at rest, which decreased with increasing age. In addition, the annual hard event rate associated with a normal test result progressively increased with age. In conclusion, pharmacologic stress echocardiography provides useful prognostic information in patients > or =65 years of age. However, its prognostic value decreases with increasing age.

Quantification of coronary flow velocity reserve by means of semiautomated analysis of coronary flow Doppler images

Coronary flow reserve (CFVR) is conventionally obtained by manual tracings of Doppler profiles, as ratio of control vs stress diastolic peak velocity. This parameter could help in discriminating between normal (N) and microcirculatory pathologic (P) subjects, even the clinical meaning of 1.9<CFVR</=2.5 it's still not clear. Our goal was to develop a technique for automated tracings of Doppler flow velocity profile to reduce subjectivity and to allow the extraction of other parameters, which could be of clinical interest. This technique was applied to 15 N (CFVR>3) and 15 P (CFVR<1.8) subjects, to assess whose of the new parameters could be able to discriminate between these groups. Results indicated that many of the new parameters were able to evidence significant differences between N and P, thus representing new clinical indices useful for the diagnosis.

Predischarge exercise electrocardiogram and stress echocardiography can predict long-term clinically driven revascularization following acute myocardial infarction

BACKGROUND

Predischarge stress testing provides suboptimal prediction of spontaneous hard events following uncomplicated acute myocardial infarction (AMI).

HYPOTHESIS

This study was aimed at assessing whether soft cardiac ischemic events requiring late revascularization could be predicted more accurately.

METHODS

In all, 428 patients undergoing exercise electrocardiography (ECG) and stress echocardiography (SE, 345 dobutamine and 83 dypiridamole) within 15 days of uncomplicated AMI were followed up for 425 (range 20-2220) days. Soft ischemic events (effort angina>class II [Canadian Cardiovascular Society Classification] and unstable angina) driving late (>6 months) revascularization were regarded as endpoints.

RESULTS

A total of 58 events (29 effort and 29 unstable angina with subsequent 47 coronary artery bypass grafts and 11 percutaneous transluminal coronary angioplasties) occurred: 26 in patients with positive exercise ECG and 34 in patients with positive SE. Univariate predictors of revascularizations were positive exercise ECG (p = 0.0001), peak wall motion score index (WMSI) (p = 0.0009), low workload (p = 0.0018), rest WMSI (p = 0.02) and positive SE (p = 0.02). Cox multivariate analysis selected peak WMSI, positive exercise ECG, and low workload positive exercise ECG as independent predictors of late revascularizations.

CONCLUSIONS

Predischarge stress testing identifies the long-term occurrence of soft ischemic events driving late revascularization after uncomplicated AMI.

Role of Contrast-Enhanced Dobutamine Stress Echocardiography in Predicting Outcome in Patients with Known or Suspected Coronary Artery Disease

Although the application of intravenous contrast agents during stress echocardiography has been shown to improve diagnostic accuracy for detecting coronary artery disease, less information exists regarding its prognostic value. The aim of this study was to determine the role of contrast-enhanced dobutamine stress echocardiography (DSE) for predicting future cardiac events in patients with coronary artery disease (CAD). We studied 893 patients (mean age: 66, 581 men) with known or suspected CAD undergoing contrast-enhanced DSE. Positivity was defined as new/worsened wall motion abnormality or fixed abnormality during stress. All patients were followed for 15 +/- 10 months to evaluate hard cardiac events (cardiac death and nonfatal myocardial infarction) and total cardiac events (hard cardiac events, congestive heart failure, unstable angina, and late revascularization). Three patients were lost to follow-up, and 128 patients developed cardiac events, including 21 hard cardiac events. The 3-year event free survival rate was significantly lower in patients with positive DSE results than in those with negative DSE results. Stepwise Cox multivariate analysis revealed that positivity of DSE (P < 0.0001, Hazard ratio (HR): 2.48) and peak wall motion score index (WMSI) >1.5 (P < 0.0001, HR: 2.41) were independent predictors for total cardiac events. Considering hard cardiac events, the independent predictors were peak WMSI > 1.5 (P < 0.0001, HR: 6.65) and age > 70 years (P < 0.005, HR: 3.27). We conclude that contrast-enhanced DSE provides important prognostic information for future cardiac events.

Incremental Prognostic Value of Stress Echocardiography Over Clinical and Stress Electrocardiographic Variables in Patients With Prior Myocardial Infarction: "Warranty Time" of a Normal Stress Echocardiogram

BACKGROUND

Patients with prior myocardial infarction (MI) are at increased risk of subsequent cardiac events (MI or cardiac death). The incremental prognostic value and warranty time of a normal stress echocardiogram in this high-risk population is not well defined.

METHODS

We evaluated 251 consecutive patients (62 +/- 11 years; 64% males) with remote history of MI (>6 weeks) undergoing stress echocardiography (83% dobutamine). Ischemia was defined as a new reversible wall motion abnormality and/or biphasic response. Follow-up for up to 4 years (mean 2.9 +/- 1.0 years) for confirmed MI (n = 7) and cardiac death (n = 15) were obtained.

RESULTS

Stress echocardiography effectively risk stratified patients into normal versus abnormal subgroups (Event rate 0.8% per year vs 4.2% per year; P = 0.01; RR = 5.6, 95% CI = 1.3-24.7). In patients with a normal stress echocardiogram, the event rate at the end of 6, 12, and 18 months were <1% per year. After 18 months the event rate in patients with a normal stress echocardiogram increased greatly (>1% per year). Stress echocardiography yields incremental prognostic value over clinical and stress electrocardiographic variables (Global chi-square increased from 12.4 to 25 to 31.1, P < 0.0001 both groups).

CONCLUSIONS

Stress echocardiography yields appropriate risk stratification and prognosis and provides incremental prognostic value over clinical and stress electrocardiographic variables even in patients with prior MI. A normal stress echocardiogram portends a benign prognosis (<1% event rate/year) for up to 18 months.

Incremental prognostic value of stress echo positivity in the left anterior descending coronary artery territory

BACKGROUND

Dipyridamole stress echo (DSE) positivity is usually titrated according to presence and severity of the induced wall motion abnormalities. The purpose of our study is to assess whether the location of DSE positivity might add to prognostic stratification.

METHODS

The study enrolled 112 patients with known or suspected coronary artery disease (CAD) and without a history of prior myocardial infarction. They were consecutively submitted to DSE (0.84 mg/Kg in 10 min followed by atropine administration, when needed) and coronary angiography (within a 15+/-7 day period). End points at follow-up were cardiac death and acute coronary syndromes.

RESULTS

Twenty-seven patients had a negative, and 85 a positive DSE (47 in the LAD territory). Angiographically assessed CAD was present in 82 patients (LAD in 59). At a follow-up of 9+/-7 months, there were 28 events of cardiac deaths or acute coronary syndromes. Event-free survival was lower in patients with positive DSE (any location) compared to those with negative DSE (47% vs 89%, p=0.003). In the subset with positive DSE, event-free survival was lower in patients with wall motion abnormalities in the LAD territory compared to those with dysfunction in the left circumflex and right coronary artery territory (31% vs 72%, p=0.00012 ). At multivariate analysis, stress echo positivity in the LAD territory was independently associated with increased risk (HR: 9.51, CI: 1.61 to 56.11, p<0.013) and outperformed angiographically assessed LAD stenosis (HR: 0.36, CI: 0.06 to 2.24, p: NS).

CONCLUSIONS

In CAD patients, wall motion abnormalities in the LAD territory during DSE identified a higher risk subgroup. Functional stress echo positivity on the LAD territory overcame the prognostic impact of an anatomic, angiographically assessed LAD disease.

Prognostic significance of ST-segment elevation during dobutamine stress echocardiography

BACKGROUND

Limited data are available concerning the significance of ST-segment elevation during dobutamine stress echocardiography (DSE). The purpose of this study was to assess the prognostic significance of new ST-segment elevation during DSE and its relationship to angiographic severity of coronary artery disease (CAD).

METHODS

From 4240 consecutive patients who had DSE, we identified 134 (3%) patients with new stress-induced ST-segment elevation > or =1 mm in at least two contiguous electrocardiographic leads. Significant CAD was considered as > or =50% diameter obstruction by angiography. Follow-up was obtained for cardiac events.

RESULTS

Age was 69 +/- 10 years; 84 (63%) were men. ST-segment elevation developed in the anterior leads in 55 (41%), inferior leads in 100 (75%), and lateral leads in 54 (40%); 56 (42%) had ST elevation in more than one region. Dobutamine stress echocardiography was abnormal in all patients; 115 (86%) had ischemia. Coronary angiography was obtained in 69 (51%) patients. Stenosis was > or =70% diameter in 68 (99%) patients and multivessel in 53 (77%). Follow-up (2.6 +/- 2.8 years) was obtained in all 134 patients. Events occurred in 103 (77%) patients, including death in 53, coronary revascularization in 33, myocardial infarction in 12, and unstable angina in 5. Event-free survival was 55% at 2 years, 38% at 4 years, and 28% at 5 years.

CONCLUSIONS

Patients with stress-induced ST-segment elevation during DSE commonly have severe CAD and are at high risk for events during follow-up. These patients should be considered for coronary angiography.

The additional prognostic value of coronary flow reserve on left anterior descending artery in patients with negative stress echo by wall motion criteria. A Transthoracic Vasodilator Stress Echocardiography Study

BACKGROUND

Vasodilator stress echocardiography allows imaging of left anterior descending (LAD) coronary flow reserve (CFR), which may provide additional prognostic information over regional wall motion.

AIM

To assess the prognostic value of CFR in patients with known or suspected coronary artery disease (CAD) and negative stress echo.

METHODS

We studied 329 consecutive patients (193 men, age 61 +/- 13 years) with known (n = 101) or suspected (n = 228) CAD and negative stress echo by standard wall motion criteria. All patients underwent dipyridamole (up to 0.84 mg/kg in 10 minutes) stress echo with CFR evaluation of LAD by Doppler.

RESULTS

During follow-up (28 +/- 10 months), 22 events occurred: 1 cardiac death, 6 nonfatal myocardial infarctions, 5 unstable anginas, and 10 late (> 6 months) coronary revascularizations. Moreover, 9 patients underwent early (< 6 months) revascularization and were censored. Using a receiver operating characteristic analysis, CFR < or = 1.92 was the best predictor of future events (area under the curve = 0.80, sensitivity = 77%, specificity = 85%) and was taken as criterion for reduced CFR accordingly. Sixty-three (19%) patients had reduced and 266 (81%) had normal CFR on LAD. The 36-month event-free survival was higher in patients with normal and lower in patients with reduced CFR (98% vs 64%, P < .0001). At Cox analysis, CFR of LAD (hazard ratio [HR] 16.52, 95% CI 5.76-47.40, P < .0001), left ventricular mass index (HR 1.03 per unit increment, 95% CI 1.00-1.05, P = .01), and smoking habit (HR 3.00, 95% CI 1.24-7.23, P = .01) were independent prognostic indicators. Using an interactive stepwise procedure, CFR on LAD provided additional prognostic information to clinical, resting echo, and angiographic findings.

CONCLUSIONS

In patients with known or suspected CAD and negative stress echocardiography by wall motion criteria, CFR provides independent information for prognostic stratification, and a reduced CFR is associated with a less benign long-term outcome.