Negative Stress Echocardiography Research Articles

Regadenoson stress echocardiography: a road ahead

Abstract Introduction Drugs used in stress echocardiography (SE) have important limitations due to side effects and contraindications. Since its approval in 2008, Regadenoson has seen a significant increase in usage. This is largely attributed to its good safety profile and diagnostic accuracy, making it the preferred drug for stress tests in many European centers. However, despite its expanding use and major advantages, current guidelines don't place it as the first choice for SE, probably because the reported experience with this drug remains limited. The aim of the present study was to assess the safety and short-medium term prognosis of patients who underwent Regadenoson SE. Methods Retrospective observational study. Patients who underwent Regadenoson SE between 2017 and 2023 were included. Safety was assessed by monitoring immediate adverse effects following Regadenoson infusion and the need for using an antidote (Aminophylline). A positive test result was defined by the occurrence of any of the following: wall motion abnormalities, left ventricle dilatation, electrocardiographic changes or symptoms of ischemia. During the follow up, we registered the incidence of ischaemic events (admission for unstable angina, acute myocardial infarction (AMI) or cardiovascular (CV) death) and other CV events such as admission for heart failure (HF) and stroke. Additionally, we evaluated patients in both groups who underwent coronary angiography (by computerized tomography or coronary catheterization) during the follow up period. The groups with negative SE (NSE) and positive SE (PSE) were compared. Results The total number of patients was 344, with a median follow up of 29 months. Basal population characteristics and events by group (NSE and PSE) are shown in Figure 1. We needed to use the antidote in only one case, because of ventricular bigeminism, with no other major adverse effects reported. SE was positive in 37 (11%) patients. In this group, patients were more likely to present ischaemic events (16% vs. 3%, p<0.01) and admissions for HF (24% vs. 5%, p <0.01), compared to the NSE one. In those who underwent coronary angiography, revascularization was needed in 14 patients of the PSE group, and only in 7 of the NSE group (38% vs 2%, p < 0.05). The indications for these last cases were persistent angina in 5 patients (2 of them with history of coronary artery disease) and revascularization following an AMI in 2 patients. (Figure 2). Conclusions The probability of an ischaemic event after a negative Regadenoson SE remains very low, unlike positive studies. Regadenoson SE showed to be both safe in assessing ischemic cardiomyopathy and very useful for its prognostic value. These findings encourage its expanding use in the stress echo lab.

Predictive ability and prognostic correlation of global longitudinal strain in patients with negative dipyridamole stress echocardiography by wall motion criteria

Abstract Background Dipyridamole stress echocardiography (DSE) is an established technique to detect coronary artery disease (CAD) and for risk stratification. Speckle Tracking Echocardiography (STE), as an objective and quantitative evaluation of ventricular function, may add incremental value to conventional stress echo analysis. Purpose To assess the prognostic value of rest (Rest-GLS) and peak (Peak-GLS) stress global longitudinal strain (GLS) in patients with suspected CAD and negative DSE according to wall motion index (WMI) criteria. Methods We retrospectively enrolled patients who underwent DSE at our centre for suspected CAD, with normal WMI. Strain Reserve was calculated as Rest GLS – Peak-GLS (Delta-GLS). We also collected data regarding other conventional parameters such as coronary flow reserve (CFR) of left anterior descending (LAD), left ventricle contractile reserve (LVCR), delta left ventricular ejection fraction (Delta-LVEF), heart rate response (HRR). Our primary endpoint was a composite of all-cause death and coronary revascularization. Receiver operating characteristic (ROC) curves were used to compare the predictive ability of the parameters. Adjusted logistic regression analyses were used to assess associations, also modelled as a restricted cubic spline. Results A total of 355 patients were included in the analysis (median age 68.2, IQR 58.2-75.2, 38.0% female). At follow-up, 58 patients met the primary endpoint. Figure 1 shows the ROC curves of different DSE parameters. Delta-GLS and Peak-GLS showed high predictive ability of composite endpoint events (area under the curve [AUC] 0.87, 95% Confidence Interval [CI] 0.82-0.92, AUC, 0.85, 95% CI 0.79-0.91, respectively), which was significantly higher compared with other DSE parameters, included Basal-GLS (P for difference for all < 0.001). After adjustments for age, previous CAD, sex, and diabetes, reducing values of Rest-GLS, Peak-GLS and Delta-GLS were significantly associated with higher odds of experiencing composite endpoint events (Basal-GLS, odds ratio [OR] 1.13, 95% CI 1.04-1.24; Peak-GLS, OR 1.45, 95% CI 1.32-1.63; Delta-GLS, OR 1.73, 95% CI 1.50-2.04). Plotting the results of the logistic regression analysis on a restricted cubic spline, reducing values of Peak-GLS and Delta-GLS showed a linear increase for the risk of adverse events, while Rest-GLS showed a plateau for lower values. Conclusion The use of GLS parameters in DSE can help to better stratify the risk for the patients since they are associated with adverse cardiovascular events.Figure 1Figure 2

Assessing Cardiovascular Risk with Coronary Artery Calcium and Carotid Intima-Media Thickness in Patients with Negative Stress Echocardiography.

Background: The role of treadmill stress echocardiography (TSE) in symptomatic patients may be limited. We evaluated whether carotid intima-media thickness (cIMT) and coronary artery calcium (CAC) scores can predict cardiovascular (CV) outcomes in patients with negative TSE. Methods: Patients who had negative TSE and measured cIMT or CAC scoring were enrolled and followed up. The primary CV outcome was defined as a composite of acute coronary syndrome, coronary revascularization, heart failure, stroke, and CV death. Results: Overall, 1095 patients participated. The median follow-up duration was 5.8 years. Patients with increased cIMT and CAC scores experienced a high incidence of primary CV outcomes (normal vs. increased group on cIMT and CAC scoring: 4.4% vs. 20.0% and 0.4% vs. 25.0%, respectively, p < 0.001). In the Cox proportional hazard model, increased cIMT and CAC scores were associated with increased primary CV outcomes (adjusted hazard ratio [95% confidence interval], p-value for increased cIMT and increased CAC scores = 2.939 [1.241-6.960], p = 0.014 and 45.192 [5.497-371.505], p < 0.001, respectively). Conclusions: Patients with increased cIMT and CAC scores have poor CV outcomes even though they have negative TSE results, and therefore, they should be carefully monitored.

Long-term prognostic value of contemporary stress echocardiography in patients with suspected or known coronary artery disease: systematic review and meta-analysis

BackgroundLong-term outcome of contemporary stress echocardiography has not been systematically assessed.ObjectiveTo evaluate the association between results of stress echocardiography and patients’ outcomes with suspected coronary artery disease using randomised controlled...

Additive negative prognostic value of coronary flow reserve in patients with left bundle branch block without inducible ischemia and without known coronary artery disease

Abstract Background Left bundle branch block (LBBB) can be isolated thing, but it is also often associated with underlying coronary artery disease (CAD). Stress echocardiography (SECHO) is widely used as an imaging method for the diagnosis of CAD. However, the diagnostic value of stress echocardiography in patients (pts) with LBBB is limited. Purpose To evaluate negative prognostic value of coronary flow reserve (CFR) in pts with LBBB without inducible ischemia and without known CAD. Methods This retrospective study included 224 pts (98, 43.8% male gender, average age 66±11 years) with LBBB and without known CAD. All the pts had negative SECHO test according the Bruce protocol. Risk factors for CAD (diabetes, smoking, hypertension, high cholesterol and positive family history of CAD), Duke treadmill score, functional capacity (Metabolic Equivalents - METs) were recorded in all pts. Out of 224 pts, in 64 (29.5%) coronary flow reserve on the left anterior descending artery was assessed using pulsed Doppler echocardiography with adenosine in a dose of 140μcg/kg/body weight during 3 minutes. As the normal value we took value of CFR ≥2. Median follow up of the pts was 72 months (IQR 56.25–132 months) for the occurrence of MACE (cardiovascular death (CVD), non-fatal myocardial infarction (nfMI), coronary artery bypass graft (CABG) and percutaneous coronary revascularization (PCI). Results Out of 224 pts, 6 (2.7%) had positive SECHO test, 2 pts (0.9%) had died due to non-cardiac causes and 11 pts (4.9%) were lost to follow up so they were excluded from further analysis. The remaining 204 pts were divided in 2 groups: 1. pts with only negative SECHO (n=144, 68.8%); 2. pts with negative SECHO and normal CFR (n=64, 31.2%). During the follow-up period 22 out of 205 pts (10.7%) had an adverse event (6 CVD, 6 nfMI, 5 CABG, 8 PCI). Between the two groups there was no significant difference in risk factors and parameters of the SECHO test. Pts with CFR had significantly lower rate of MACE compared to the pts with only SECHO test (2, 3.1% vs 20, 14.2%, p=0.018, respectively). Using the Cox regression analysis, univariate predictors of MACE were insulin dependent diabetes (HR 10.851 [95% CI 2.095–56.220], p=0.004), Duke score (HR 0.603 [95% CI 0.414–0.878], p=0.008), and MET (HR 0.393 [95% CI 0.209–0.737], p=0.004). In the multivariate analysis only the insulin dependent diabetes remained an independent predictor of MACE (HR 6.906 [95% CI 1.100–43.363], p=0.039). Using the Kaplan-Meier survival curve we see that the pts with SECHO test and CFR had shorter event-free time compared to the pts with SECHO test (136.3±3.6 months vs 149.8±2.9 months, Log Rank 4.022, p=0.045) (Figure 1). Conclusion Normal value of CFR has good negative prognostic value in pts with LBBB without inducible ischemia and without known CAD, while pts with insulin dependent diabetes have more pronounced risk for the occurrence of adverse events. Funding Acknowledgement Type of funding sources: None.

Does diabetes increase the risk of cardiovascular events in patients with negative treadmill stress echocardiography?

Cardiovascular morbidity and mortality rates are considered to be high in patients with diabetes despite negative stress test results; however, little data are available to support this supposition. We compared the long-term cardiovascular events between patients with diabetes and those without diabetes with negative treadmill stress echocardiography and evaluated the predictors for cardiovascular events in patients with diabetes. A total of 1,243 consecutive patients (mean age, 56 ± 10 years; non-diabetics: diabetics, 975:268; mean follow-up of 5 years) with negative treadmill stress echocardiography were evaluated. Clinical data were examined, and major adverse cardiovascular events (MACEs, a composite of coronary revascularization, acute myocardial infarction, and cardiovascular death) were compared between the non-diabetic and diabetic groups. In the population matched by clinical characteristics, the diabetic and non-diabetic groups had similar occurrence of MACEs (non-diabetics vs. diabetics = 5% versus 7%; p = 0.329) and event-free survival. MACEs in the diabetic group were associated with elevated early diastolic velocity of the mitral inflow/mitral annulus (E/e') ratio, indicative of diastolic dysfunction. The absence of statin and dipeptidyl peptidase-4 inhibitor use and use of sulfonylureas were also predictors of more MACEs. In conclusion, long-term cardiovascular events in patients with diabetes and negative stress echocardiography were comparable to those in patients without diabetes. However, appropriate monitoring of diastolic dysfunction, statin use, and individualized antidiabetic drug selection are required to reduce the cardiovascular risk in patients with diabetes.

Major adverse cardiac events after emergency department evaluation of chest pain patients with advanced testing: Systematic review and meta-analysis.

Our primary objective was to describe the risk of major adverse cardiac events (MACE) at 1, 6, and 12months after a negative coronary computed tomography angiogram (cCTA), electrocardiogram (ECG) stress test, stress echocardiography, and myocardial perfusion scintigraphy (MPS) in low- to intermediate-risk patients. Initially, 952 articles were identified for screening, 81met criteria for full-text review, and once risk of bias was assessed, 33 articles were included in this meta-analysis. We utilized a random-effects model to assess pooled MACE event proportion for patients undergoing evaluation of acute coronary syndrome (ACS) when risk stratified to a low- to intermediate-risk category after undergoing standard testing. Heterogeneity analysis was performed using Cochrane's Q-test and I2 statistic. Twenty-one studies evaluated follow-up at 1month with cCTA having a 0.09% (95% confidence interval [CI]= 0.03% to 0.26%) pooled MACE compared to 0.23% (95% CI= 0.01% to 5.8%) of the exercise stress testing (p=1). MPS and cCTA had an overall event rate of 0.15% (95% CI= 0.06% to 0.41%) at 6months (I2 =0%). At 12months, a subgroup analysis found a pooled cCTA MACE of 0.16% (95% CI= 0.04% to 0.65%) compared to 1.68% (95% CI= 0.01% to 2.6%) for stress echocardiography with low within-group heterogeneity (I2 =0%). Subgroup analysis of cCTA with no disease versus nonobstructive disease (<50% stenosis) did not find statistical difference in the MACE at both 1 month (0.17% [95% CI= 0.04% to 0.67%] vs. 0.06% [95% CI= 0.01% to 0.34%]) and 12months (0.44% [95% CI= 0.09% to 2.2% vs. 0.54% [95% CI= 0.19% to 1.5%]). Patients presenting with chest pain who have a coronary CTA showing < 50% stenosis, negative ECG stress test, stress echocardiography, or stress myocardial perfusion scan in the past 12months can be discharged without any further risk stratification if their ECG and troponin are reassuring given low MACE.

Myocardial injury in stress echocardiography: comparison of dobutamine, dipyridamole and dynamic stress echocardiography – single centre study

Abstract Background Stress echocardiography (SE) plays important role in investigation of the patients with chest pain. Adverse events rate is higher in dobutamine stress echocardiography on comparison to dobutamine stress echocardiography (ExSE) or dipyridamole stress echocardiography (DIP). Dynamic stress (ExSE) is recommended as the first-choice method according to the current guidelines. Purpose Response to the different stressors was studied in several studies with controversial results. This study aimed to investigate myocardial injury during stress echocardiography measured by the serum high sensitivity troponin (hsTnT) in a low risk population and whether there is a difference in hsTnT response between various stressors. Methods 135 patients (DSE n=46, ExsE n=46, Dip n=43) investigated for chest pain with suspicion on angina with negative diagnostic stress echocardiography were enrolled in the study. HsTnT was measured before and at 180 min. after the test was terminated. Patients with baseline elevated hsTnT levels (≥14 pg/ml), impaired LV EF (&amp;lt;50%), regional wall motion abnormalities, previous acute coronary syndrome and/or revascularisation, known epicardial coronary artery stenosis &amp;gt;50%, diabetes, prediabates (fasting glycemia at the day of the test ≥5,6 mmol/l, left ventricle hypertrophy &amp;gt;13 mm, baseline uncontrolled hypertension (BP &amp;gt;160/100 mmHg), estimated systolic pulmonary pressure &amp;gt;45 mmHg, more than moderate valvular disease, and patient who experienced dobutmine side effect (hypotension, atrial fibrillation) were excluded from the study. Results HsTnT increased in DSE and ExSE, but not in DIP group [9,4 (1,5–58,6), 1,1 (−0,9–15,7), −0,1 (−1,4–2,1) ng/L, p&amp;lt;0,001]. Similar result was found In DSE and ExSE subgroups without atropine [5,3 (0,4–45,3) vs 1,1 (−1,1–15,7) ng/L, p&amp;lt;0,001]. Adding atropine during SE triggered much greater hsTnT release in DSE [40,1 (3,7–160,3) vs 5,3 (0,4–45,3) ng/L, p&amp;lt;0,001], but not in ExSE group [0,6 (−0,9–22,7) vs 1,1 (−1,1–15,7) ng/L, p=0,786]. Moderate correlation of hsTnT rise with DSE length was observed (r=0,43). Conclusions DSE leads to significant myocardial injury multiplied when atropine is used. No injury was observed in DIP and only mild was revealed in ExSE. This finding support ExSE as the preferred stress echocardiography method. Whether significant myocardial injury is causative of the higher adverse event rates in DSE remains to be determined. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): University Hospital Hradec Kralove, Czech RepublicFaculty of Medicine Hradec Kralove, Charles University, Czech Republic hsTnT change 0–180 min. the whole grouphsTnT change 0–180 min. w/wo atropine

Abstract 16183: Predictors of Myocardial Injury in Patients With Negative Stress Echocardiogram

Background: A negative result on stress echocardiography (SE) is generally associated with a low risk of cardiovascular events and carries a favorable prognosis. The present study was conducted to identify clinical and echocardiographic characteristics associated with increased risk of myocardial injury following a negative SE (NSE). Methods: We retrospectively identified a total of 4130 SEs performed between 2013 and 2017 at a tertiary care center. NSE was defined as the absence of a new or worsening wall motion abnormality (WMA) with stress. Patients with resting WMA on SE were excluded. The occurrence of myocardial injury following index SE within 1 year was then recorded. Myocardial injury was defined as an elevated (&gt;99 th percentile of the upper reference limit of normal) and changing troponin value (a rise and/or fall of the troponin value observed) following index SE. Results: During the study period, 2962 patients with NSE met inclusion criteria (median age 58 years-old; 50% females). Baseline characteristics were as follows: 35% diabetic, 49% hyperlipidemic, 62% hypertensive, 41% had a history of smoking, 21% had a history of coronary artery disease (CAD), 24% had end-stage liver disease (ESLD), 5% had end-stage renal disease (ESRD) and 1.5% had a left ventricular ejection fraction (LVEF) &lt; 50%. Around 5% of patients developed myocardial injury within 1 year of NSE. Age, diabetes mellitus, ESLD and a LVEF &lt;50% were significantly associated with an increased risk of myocardial injury on univariate and multivariate analysis (p&lt;0.013) (Table). Conclusion: Patients with age &gt; 65 years, diabetes mellitus, ESLD and a LVEF &lt;50% were found to be at increased risk of myocardial injury within 1 year of a NSE. These characteristics should be accounted for during the interpretation of SE as these patients warrant intensive risk factor modification and close follow-up.

Accuracy and Prognostic Value of Physiologist-Led Stress Echocardiography for Coronary Disease

We demonstrated that physiologist-led stress echocardiography (PLSE) is feasible for coronary artery disease (CAD) assessment. We sought to extend our work by assessing its accuracy and prognostic value. Retrospective study of 898 subjects undergoing PLSE (n=393) or cardiologist-led stress echocardiography (CLSE) (n=505) for CAD assessment using exercise or dobutamine. For accuracy assessment, the primary outcome was the ability of stress echocardiography to identify significant CAD on invasive coronary angiography (ICA). Incidence of 24-month non-fatal MI, total and cardiac mortality, revascularisation and combined major adverse cardiac events (MACE) were assessed. Demographics, comorbidities, CAD predictors, CAD pre-test probability and cardiac medications were matched between the PLSE and CLSE groups. PLSE had high sensitivity, specificity, positive and negative predictive value and accuracy (85%, 74%, 69%, 88%, 78% respectively). PLSE accuracy measures were similar and non-inferior to CLSE. There was a similar incidence of individual and combined outcomes in PLSE and CLSE subjects. Negative stress echocardiography conferred a comparably low incidence of non-fatal MI (PLSE 1.4% vs. CLSE 0.9%, p=0.464), cardiac mortality (0.6% vs. 0.0%, p=0.277) and MACE (6.8% vs. 3.1%, p=0.404). This is the first study of the accuracy compared with gold standard of ICA, and prognostic value of PLSE CAD assessment. PLSE demonstrates high and non-inferior accuracy compared with CLSE for CAD assessment. Negative PLSE and CLSE confer a similarly very low incidence of cardiac outcomes, confirming for the first time the important prognostic value of PLSE.

Exercise induced reduction in myocardial work predicts significant coronary artery disease in patients with false negative stress echocardiography

Abstract Stress echocardiography (SE) is a reliable technique for the diagnosis of coronary artery disease (CAD) with high sensitivity and specificity. However in patients with small left ventricular (LV) cavity caused by marked concentric hypertrophy the sensitivity of SE is low. We assumed that in patients with false negative SE evaluation of global myocardial work (GW) might detect significant CAD. Methods 238 patents with chest pain (98 female, mean age 61±5 years) without history of CAD were referred to SE for CAD confirmation. 94 (39.5%) patients had negative SE and were enrolled in our study for re-examination. Age and gender matched 50 healthy subjects served as controls. GW index (GWI) was obtained from pressure-strain loops composed from speckle tracking analysis indexed to brachial systolic blood pressure. Global constructive work (GCW) as the sum of positive work due to myocardial shortening during systole and negative work due to lengthening during isovolumic relaxation, global wasted work (GWW) as energy loss by myocardial lengthening in systole and shortening in isovolumic relaxation, and GW efficiency (GWE) as the percentage ratio of constructive work to the sum of constructive work and wasted work were measured after submaximal treadmill SE at the heart rate of 100–110 beats per minute (109±11 s after SE) using EchoPac software by blinded experienced echocardiographer. All patients were referred to coronary angiography after re-examination. Results 42 (44.7%) patients had lower GWI values than the lowest limit of GWI value in controls. These patients had significant reduction in GWI, compared with remaining 52 patients in whom GWI did not differ from those of controls (GWI 1897±112 mmHg% vs 2518±243 mmHg%, p&amp;lt;0.01). GCW, GWE and GWW were comparable between patients with or without reduced GWI (GCW 2283±107mmHg% vs 2321±110 mmHg%, p=NS; GWE 96.9±1.1% vs 97.4±1.2%, p=NS; GWW 57±3 mmHg% vs 53±4 mmHg%, p=NS). 28 (66.7%) of 42 patients with GWI reduction and 8 (15.0%) of 52 patients without GWI reduction had at least one vessel significant CAD. GWI had sensitivity, specificity, and accuracy in detection of CAD 78%, 76%, 77% respectively with 67% positive predictive value, and 85% negative predictive value. 29 (80.5%) patients out of 36 with significant CAD had concentric increase in LVMi compared with true negative SE patients (83±6 g/m2 vs 71±4 g/m2, p&amp;lt;0.01). GWI was the predictor of significant CAD (area under the curve 0.793). Conclusion GWI extends diagnostic power of conventional SE in detection of CAD, especially in patients with smaller LV cavity due to concentric hypertrophy when sensitivity of conventional SE is low. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): Committee of Sience at Ministry of Education of Republic of Armenia

Long-term prognosis and predictors of outcomes after negative stress echocardiography

Negative stress echocardiography (NSE) is associated with low cardiovascular morbidity and overall mortality. We aimed to determine the clinical and echocardiographic predictors of overall and cardiovascular outcomes following NSE. Patients who underwent SE between 2013 and 2017 were reviewed. Patients with a history of solid organ transplant or being evaluated for transplant, history of end-stage renal or liver disease, and positive SE were excluded. NSE results were divided into negative diagnostic if patient reached target heart rate (THR) and had no wall motion abnormality (WMA) at rest or stress; negative non-diagnostic if patient had no WMA but did not reach THR or if image quality was non-diagnostic; and abnormal non-ischemic if patient had a resting WMA not worsened at stress along with a personal history of coronary artery disease (CAD). New CAD lesion at 1year was defined as ≥ 50% stenosis on cardiac catheterization. Of 4119 patients with SE, 2575 were included. All-cause mortality rate was 1.1%/year and CAD rate was 3.1%/year. Predictors of all-cause mortality were age, male gender, history of smoking and being selected for dobutamine SE. Predictors of a new CAD lesion at 1year were male gender, diabetes, personal history of CAD and abnormal non-ischemic SE. We identified clinical and echocardiographic characteristics in a subset of NSE patients who are at higher risk for subsequent adverse events. These characteristics should be accounted for during the clinical interpretation of SE, and patients found at increased risk for morbidity and mortality warrant continued follow-up.

Factors Associated with Non-calcified Plaques in Patients with Coronary Artery Calcium Score of Zero

Background: The coronary artery calcium score is used for risk stratification in asymptomatic patients. Although coronary arterydisease can occur in the absence of coronary artery calcifications, no conditions associated with the presence of soft non-calcifiedplaques have been described in this scenario, beyond the presence of symptoms.Objectives: The aim of this study was to determine the associations between non-calcified plaques and independent variables inpatients with coronary artery calcium score of zero.Methods: Consecutive patients with coronary artery score of zero Agatston units who also underwent computed tomography coronaryangiography were included in the study. Univariate logistic regression analysis was used to find associations. (15) Sensitivity,specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LH+) and negative likelihoodratio (LH-) were calculated.Results: Among a total of 93 patients, 10% (n = 9) presented non-calcified plaque. A positive exercise stress test was associated withplaques of any degree of severity (OR 6.5; 95% CI, 1.3-33, p = 0.02). This association persisted for non-severe plaques when the positiveexercise stress test was combined with a negative myocardial perfusion SPECT or stress echocardiography for ischemia (OR,12.4; 95% CI 1.5-101, p = 0.02). Sensitivity and specificity of ST-segment depression for non-calcified plaque of any degree of severitywas 44.4% and 86%, respectively, with NPV of 94%, PPV of 25%, LR+ of 3.11 and LR– of 0.65.Conclusions: ST-segment depression could be associated with non-calcified plaques in patients without coronary artery calcifications,even with normal exercise stress myocardial perfusion or wall motion (non-obstructive disease).

Minimal Patient Clinical Variables to Accurately Predict Stress Echocardiography Outcome: Validation Study Using Machine Learning Techniques.

BackgroundStress echocardiography is a well-established diagnostic tool for suspected coronary artery disease (CAD). Cardiovascular risk factors are used in the assessment of the probability of CAD. The link between the outcome of stress echocardiography and patients’ variables including risk factors, current medication, and anthropometric variables has not been widely investigated.ObjectiveThis study aimed to use machine learning to predict significant CAD defined by positive stress echocardiography results in patients with chest pain based on anthropometrics, cardiovascular risk factors, and medication as variables. This could allow clinical prioritization of patients with likely prediction of CAD, thus saving clinician time and improving outcomes.MethodsA machine learning framework was proposed to automate the prediction of stress echocardiography results. The framework consisted of four stages: feature extraction, preprocessing, feature selection, and classification stage. A mutual information–based feature selection method was used to investigate the amount of information that each feature carried to define the positive outcome of stress echocardiography. Two classification algorithms, support vector machine (SVM) and random forest classifiers, have been deployed. Data from 529 patients were used to train and validate the framework. Patient mean age was 61 (SD 12) years. The data consists of anthropological data and cardiovascular risk factors such as gender, age, weight, family history, diabetes, smoking history, hypertension, hypercholesterolemia, prior diagnosis of CAD, and prescribed medications at the time of the test. There were 82 positive (abnormal) and 447 negative (normal) stress echocardiography results. The framework was evaluated using the whole dataset including cases with prior diagnosis of CAD. Five-fold cross-validation was used to validate the performance of the framework. We also investigated the model in the subset of patients with no prior CAD.ResultsThe feature selection methods showed that prior diagnosis of CAD, sex, and prescribed medications such as angiotensin-converting enzyme inhibitor/angiotensin receptor blocker were the features that shared the most information about the outcome of stress echocardiography. SVM classifiers showed the best trade-off between sensitivity and specificity and was achieved with three features. Using only these three features, we achieved an accuracy of 67.63% with sensitivity and specificity 72.87% and 66.67% respectively. However, for patients with no prior diagnosis of CAD, only two features (sex and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use) were needed to achieve accuracy of 70.32% with sensitivity and specificity at 70.24%.ConclusionsThis study shows that machine learning can predict the outcome of stress echocardiography based on only a few features: patient prior cardiac history, gender, and prescribed medication. Further research recruiting higher number of patients who underwent stress echocardiography could further improve the performance of the proposed algorithm with the potential of facilitating patient selection for early treatment/intervention avoiding unnecessary downstream testing.

Prognostic impact of stress echocardiography with discordant stress electrocardiography in patients with suspected coronary artery disease.

During stress echocardiography, the echocardiologist routinely collects both echocardiographic images and stress electrocardiogram (ECG) concurrently. The managing physician faces a dilemma when the stress ECG and stress echocardiography results are discordant; for example, when a patient has negative stress echocardiography but positive stress ECG. We therefore sought to evaluate the prognostic value of stress echocardiography in relation to concordant or discordant stress ECG findings in our local Singapore setting, which has a well-defined Southeast Asian population. This was a retrospective observational study of all patients who underwent stress echocardiography in 2012 at Changi General Hospital, Singapore. All study patients were followed up for 18 months via electronic medical records. There was no difference in the major adverse cardiovascular events (MACE) outcome of patients with normal stress echocardiography and normal stress ECG (reference group) as compared with patients with normal stress echocardiography but positive (discordant) stress ECG (odds ratio 2.02, 95% confidence interval 0.82‒4.98; p = 0.125). This study will help to reassure cardiologists that discordant results (negative stress echocardiography but positive stress ECG) do not portend a higher risk of MACE when compared to concordant results (i.e. both stress echocardiography and stress ECG are negative).

PREDICTORS OF INCREASED MORTALITY RISK IN PATIENTS WITH NEGATIVE STRESS ECHOCARDIOGRAPHY

A negative result on stress echocardiography (SE) is associated with low risk (<1% per year) of adverse events and carries a favorable prognosis. We sought to identify predictors of increased mortality risk in a group of patients with negative SE (NSE). We reviewed a total of 4130 SEs performed

P245 Acute ST segment elevation MI in a patient following negative dobuatmine stress echocardiography: Possible mechanisms and lessons to learn

Abstract Funding Acknowledgements No Funding Background Dobutamine stress echocardiography (DSE) has been used as a safe stress modality for assessing myocardial ischemia. Acute myocardial infarction is one of the rare complications of DSE. In this report, we will discuss a case of a 60 year old lady who developed anterior ST-segment elevation myocardial infarction(STEMI) after a negative DSE. Case report 60 year old lady with a background of PCI to LAD in 2009 presented with angina , a repeat angiogram showed mild to moderate in stent restenosis (ISR) within the LAD but instant wave-free ratio (IFR ) was 0.94 , Fractional Flow Reserve(FFR) 0.84 and negative IVUS studies. Despite that, the patient continued to have chest pain with effort and therefore a DSE was requested. The patient was stressed with intravenous Dobutamine with a maximum dose of 40mcg/kg/min plus 600mcg of atropine. There was no evidence of ischemia. The Patient developed chest pain 15 minutes later. ECG was done and showed ST elevation in anterior leads. Urgent angiography was undertaken which showed acute thrombotic occlusion in the mid LAD with TIMI 0 flow (within the area where ISR had been seen previously) (fig1) . Percutaneous intervention was undertaken and TIMI III flow was restored. Discussion Acute STEMI within a few hours after normal DSE is very rare with an incidence of 0.02% (range 0.00% to 0.10%) Plaque destabilisation and rupture are the possible underlying mechanisms behind coronary occlusion. Interestingly, most of the cases happen within 30 mins after the test. The activation of sympathetic nervous system leads to increased catecholamines, blood viscosity, arterial pressure and heart rate, which are accompanied by detectable increase in platelet aggregation and decrease in fibrinolytic activity that both tend to favour thrombosis. This could lead to propagation of mural thrombus overlying a small plaque erosion that might otherwise have been harmless. Another interesting learning point is the correlation between chronotropic incompetence (CI) and myocardial ischaemia. Low basal heart rate is one of the predictors of CI (baseline average heart rate of 60 bpm in our case, and she managed to achieve only 81% of target Heart rate (THR) despite the maximum dose of dobutamine and atropine). Many studies examined the significance of CI. Impaired Chronotropic response is associated with an increased risk of mortality and MI. Possible explanation is that patients with CI fail to demonstrate or underestimate extent of ischemia. With the experience of our case and similar cases from the literature, we suggest symptoms of chest pain should be seriously attended even after a normal DSE. The risk of life-threatening complication should be informed to patients and enough time should be taken for observation post stress test. More research is needed to clarify the role of DSE in CI patients on account of its potential normal result with submaximal THR and risk of life threatening cardiac event. Abstract P245 Figure. Coronary Angiogram fig1

1673 Accuracy and prognostic value of physiologist-led stress echocardiography for coronary disease

Abstract Funding Acknowledgements No funding sources Background Cardiac physiologist-led stress echocardiography (PLSE) services provide potential for expansion of SE services and increased productivity for cardiologists. There is no published data on the accuracy or prognostic value of PLSE. Purpose To assess and compare the accuracy and prognostic value of PLSE and cardiologist-led stress echocardiography (CLSE) for CAD assessment Methods Retrospective study of 898 subjects undergoing PLSE (n = 393) or CLSE (n = 505) for CAD assessment using exercise or dobutamine. For accuracy assessment, the primary outcome was the ability of stress echocardiography to identify significant CAD on invasive angiography (ICA). Incidence of 24-month non-fatal myocardial infarction (MI), total and cardiac mortality, revascularisation and combined major adverse cardiac events (MACE) were assessed. Results Demographics, comorbidities, CAD predictors and cardiac medications were matched between the PLSE and CLSE groups. PLSE had high sensitivity, specificity, positive and negative predictive value and accuracy (85%, 74%, 69%, 88%, 78% respectively). PLSE accuracy measures were similar and non-inferior to CLSE. There was a similar incidence of individual and combined outcomes in PLSE and CLSE subjects. Negative stress echocardiography conferred a low incidence of non-fatal MI (PLSE 1.4% vs. CLSE 0.9%, p = 0.464), cardiac mortality (0.6% vs. 0.0%, p = 0.277) and MACE (6.8% vs. 3.1%, p = 0.404). Conclusion This is the largest study of PLSE accuracy and first study of the prognostic value of PLSE. PLSE demonstrates high and non-inferior accuracy compared with CLSE for CAD assessment. Negative PLSE and CLSE confer a similarly very low incidence of cardiac outcomes, confirming for the first time the important prognostic value of PLSE. Accuracy of PLSE and CLSE for CAD Marker of diagnostic test Total (n = 72) PLSE (n = 32) CLSE (n = 40) p Significant CAD present (n, %) 20 (27.8%) 12 (37.5%) 8 (20.0%) 0.167 * Single-vessel CAD 12 (60.0%) 7 (58.3%) 5 (62.5%) 0.325 * Multi-vessel CAD 8 (40.0%) 5 (41.7%) 3 (37.5%) 0.325 Sensitivity 76% (66-76%) 85% (73-97%) 63% (48-78%) Non-significant Specificity 73% (63-73%) 74% (59-89%) 72% (58-86%) Non-significant Positive predictive value (PPV) 53% (42-64%) 69% (53-85%) 29% (15-43%) Significant Negative predictive value (NPV) 88% (80-96%) 88% (77-99%) 88% (78-98%) Non-significant Overall accuracy 74% (64-84%) 78% (64-92%) 70% (56-84%) Non-significant Accuracy data expressed as value (95% confidence interval). CAD= coronary artery disease. Differences in values between PLSE and CLSE considered statistically significant if no crossover in 95% confidence intervals Abstract 1673 Figure. Predicted coronary artery lesion from SE

P1788 Prognostic value of stress echocardiography in preoperative risk stratification and management

Abstract Introduction The prognostic value of pharmacologic stress echocardiography has been extensively demonstrated in patients undergoing noncardiac surgery since 42% of the perioperative complications are cardiac. Coronary artery stenoses can became flow-limiting due to hemodynamic fluctuations in this period leading to myocardial ischemia. Purpose Evaluation of prognostic value of pharmacologic stress echocardiography in preoperative risk stratification. Methods Single center retrospective analysis of patients’ data referred to perform a preoperative risk stratification through pharmacological stress echocardiography between January 2014- December 2018. Data was collected regarding clinical and echocardiographic parameters to predict perioperative cardiac complications (myocardial infarction and development of arrythmias) and evaluate the impact of the result of DSE in patients´ clinical management. Results Of 910 pharmacological stress echocardiograms, 106 were performed to evaluate preoperative risk. Patients´ mean age was 66 ± 11 years, 85% males. 64% had hypertension, 45% dyslipidaemia, 38% current smokers and 18% diabetes. 189% had previously myocardial infarction and 9% stroke. All patients were proposed to intermediate-high risk surgeries: 73% to vascular surgery, 14% to kidney transplant and 13% to other type of surgery (especially abdominal surgery). Most of the stress tests (64%) were performed with dobutamine and the others 34% with dipyridamole. 91% of stress echocardiography were negative, 6% positive and 4% inconclusive. The patients with a positive stress test was submitted to coronary angiography to treat relevant lesions and cardiovascular risk factors were optimized. 72% of the patients has already been submitted to the proposed surgery; in this population, there was a 5% rate of cardiac complications following the surgery, all in patients with previous negative stress echocardiography. Complications were non-ST elevation myocardial infarction in 1% and de novo atrial fibrillation in 4%. Half of the patients with a positive stress echocardiography were operated with no cardiac perioperative complications, possibly related to patient´s optimization before the surgery; in the other half it was decided not to perform the surgery due to the potential cardiac risk. Predictor factors for perioperative cardiac complications, evaluated through univariate and multivariate analysis, were age (odds ratios (OR) 1.232, confidence interval (CI) 1.043-1.456, p 0.007) and stroke (OR 0.057, CI 0.947-44.592, p 0.033). Conclusion In our study, patients with a positive stress echocardiography were optimized before the surgery leading to none cardiac perioperative complications, emphasizing the importance of this test in preoperative patients´ management.

P1511Promising prognostic value of negative stress echocardiography in patients with incomplete revascularization after successful primary PCI

Abstract Background The specific role of non-invasive functional testing in a risk stratification of patients with incomplete revascularization after primary percutaneous coronary intervention (pPCI) still needs to be evaluated. The aim of our study was to assess negative prognostic value of stress echocardiography (SECHO) after successful pPCI and incomplete revascularization of non-culprit lesions. Methods Our study consisted of 202 patients (mean age 59±10 years, male 142) successfully treated with pPCI, who performed SECHO according to Bruce protocol in order to assess residual ischemia in coronary artery with non-culprit lesion. Duke treadmill score, functional capacity (Metabolic Equivalents - METs), achieved target heart rate (THR), heart rate recovery (HRR), wall motion score index (WMSI) and ejection fraction were interrogated in all patients. Slow HRR was defined as ≤18 beats/min. Median follow-up of the patients was 70 months (IQR 55–83 months) for the occurrence of cardiovascular death and non-fatal myocardial infarction. We also assessed the independent predictors for the occurrence of the adverse events. Results Out of 202 patients, 42 (20.8%) had positive SECHO test, 4 patients (1.98%) had died due to non-cardiac causes and 7 patients (3.5%) were lost to follow-up. From the remaining 149 patients with negative SECHO, 13 (8.7%) had an adverse event (7 cardiovascular deaths and 6 non-fatal MI). Negative predictive value of SECHO test was 91.3%. Univariate predictors of adverse events were slow HRR (HR 4.343 [95% CI 1.473–14.011], p=0.008), and not achieved THR (HR 0.322 [95% CI 0.105–0.985], p=0.047). By multivariate analysis, only slow HRR remained independent predictor of adverse events (HR 3.324 [95% CI 1.013–10.906], p=0.048). Conclusion SECHO test has excellent negative prognostic value in patients with incomplete revascularization of non-culprit lesions after successful pPCI. Still, particular care should be taken to the patients with slow HRR and negative SECHO due to increased risk for the occurrence of adverse events. Acknowledgement/Funding Ministry of Education and Science of the Republic of Serbia (Grant No III41022)