Noninvasive Stress Imaging Research Articles

Use of downstream stress imaging tests for risk stratification of patients presenting to the emergency department with chest pain and low HEART score

BackgroundPatients with low HEART (History, Electrocardiogram, Age, Risk factors, and Troponin level) risk scores who are discharged from the emergency department (ED) may present clinical challenges and diagnostic dilemmas. The...

Comprehensive Angiography-Derived Functional Assessment of Epicardial and Microvascular Coronary Disease. Correlation With Non-invasive Myocardial Stress Imaging

Coronary angiography (CA) is poorly correlated with non-invasive myocardial stress imaging (NSI) and myocardial ischemia is often observed in patients with unobstructed coronary arteries. Moreover, the diagnostic performance of combined epicardial and microcirculatory angiography-derived physiological assessment and its correlation with NSI remains unknown. Nine-hundred-seventeen coronary vessels in 319 patients who underwent both CA and NSI were included in this multicenter observational retrospective analysis. Quantitative flow ratio (QFR) and angiography-derived index of microcirculatory resistance (IMRangio) analyses were performed to estimate coronary epicardial and microcirculatory function respectively. NSI demonstrated evidence of myocardial ischemia in 76% of the cases. IMRangio (36 [22-50] vs 29 [21-41], p<0.001) was significantly higher and QFR (0.92 [0.78-0.99] vs 0.97 [0.91-0.99], p<0.001) was significantly lower in vessels subtending ischemic territories. Overall, the diagnostic accuracy of QFR was moderate (AUCROC 0.632 [95% CI 0.589-0.674], p<0.0001) but it was higher in patients with normal microcirculatory function (AUCROC = 0.726 [95% CI 0.669-0.784], p<0.0001, p-value for AUCROC comparison=0.009). Combined QFR/IMRangio assessment provided incremental diagnostic performance compared with the evaluation of epicardial or microcirculatory districts in isolation (p-value for AUC comparison <0.0001) and it was able to identify the predominant mechanism of myocardial ischemia in 77% of the patients with positive NSI. Our study suggests the value of a combined angiography-derived assessment of epicardial and microvascular function for the definition of the predominant mechanism of myocardial ischemia in patients with suspected coronary artery disease.

Sensitivity and specificity of non-invasive stress imaging techniques - an outdated paradigm in contemporary clinical cardiology?

Journal Article Accepted manuscript Sensitivity and specificity of non-invasive stress imaging techniques – an outdated paradigm in contemporary clinical cardiology? Get access Benoy Nalin Shah, MD FRCP FESC, Benoy Nalin Shah, MD FRCP FESC Wessex Cardiac Centre, Southampton General Hospital, SouthamptonUK Cardiac Administration Offices, Level E North Wing, Southampton General Hospital, Tremona Road, Southampton, Hampshire – SO16 6YD, England, Phone/E-mail/Twitter: +442381205918/benoy.shah@uhs.nhs.uk/@dr_benoy_n_shah https://orcid.org/0000-0001-9681-7311 Search for other works by this author on: Oxford Academic PubMed Google Scholar Roxy Senior, FACC FESC FRCP Roxy Senior, FACC FESC FRCP Department of Echocardiography, Royal Brompton Hospital, London, UKNational Heart & Lung Institute, Imperial College London, UK https://orcid.org/0000-0001-6289-7050 Search for other works by this author on: Oxford Academic PubMed Google Scholar European Heart Journal - Cardiovascular Imaging, jead144, https://doi.org/10.1093/ehjci/jead144 Published: 21 June 2023 Article history Received: 12 June 2023 Accepted: 17 June 2023 Published: 21 June 2023

Predictors of Left Main Coronary Artery Disease in the ISCHEMIA Trial

BackgroundDetection of ≥50% diameter stenosis left main coronary artery disease (LMD) has prognostic and therapeutic implications. Noninvasive stress imaging or an exercise tolerance test (ETT) are the most common methods to detect obstructive coronary artery disease, though stress test markers of LMD remain ill-defined. ObjectivesThe authors sought to identify markers of LMD as detected on coronary computed tomography angiography (CTA), using clinical and stress testing parameters. MethodsThis was a post hoc analysis of ISCHEMIA (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches), including randomized and nonrandomized participants who had locally determined moderate or severe ischemia on nonimaging ETT, stress nuclear myocardial perfusion imaging, or stress echocardiography followed by CTA to exclude LMD. Stress tests were read by core laboratories. Prior coronary artery bypass grafting was an exclusion. In a stepped multivariate model, the authors identified predictors of LMD, first without and then with stress testing parameters. ResultsAmong 5,146 participants (mean age 63 years, 74% male), 414 (8%) had LMD. Predictors of LMD were older age (P < 0.001), male sex (P < 0.01), absence of prior myocardial infarction (P < 0.009), transient ischemic dilation of the left ventricle on stress echocardiography (P = 0.05), magnitude of ST-segment depression on ETT (P = 0.004), and peak metabolic equivalents achieved on ETT (P = 0.001). The models were weakly predictive of LMD (C-index 0.643 and 0.684). ConclusionsIn patients with moderate or severe ischemia, clinical and stress testing parameters were weakly predictive of LMD on CTA. For most patients with moderate or severe ischemia, anatomical imaging is needed to rule out LMD. (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches [ISCHEMIA]; NCT01471522)

Changes in the diagnosis and non-invasive treatment of chronic coronary syndromes in the last three European Society of Cardiology guidelines.

One of the most common forms of ischemic heart disease is chronic coronary syndromes (CCS), formerly known as stable coronary artery disease. During the last 15 years, the European Society of Cardiology has modified the guidelines for the diagnosis and treatment of CCS three times. The aim of this study was to analyze the changes in non-invasive diagnostics and pharmacotherapy of CCS that occurred in the last three guidelines. In non-invasive diagnostics, the most important change was reduction of the role of the electrocardiographic exercise test in favor of non-invasive stress imaging tests and computed tomography angiography. In pharmacotherapy, the role of β-blockers and calcium channel blockers has increased in controlling heart rate and symptoms. Intensive hypolipemic treatment for prevention of cardiovascular events and treatment with low doses of novel oral anticoagulants for those at high risk of cardiovascular events with sinus rhythm are among the recommendations.

Diagnostic accuracy of Instantaneous Wave-Free Ratio (iFR) for the assessment of myocardial ischaemia: a comparison with non-invasive stress imaging

Abstract Background Instantaneous Wave-Free Ratio (iFR) allows for the assessment of the haemodynamic effects of epicardial coronary stenoses without the need for hyperaemia; iFR is currently recommended as a means to evaluate myocardial ischaemia. Purpose To assess the diagnostic accuracy of iFR with respect to the identification of coronary epicardial stenoses causing ischemia. Therefore, we combined anatomical (% stenosis at invasive coronary angiography, ICA) and functional (non-invasive imaging stress test, NIST) information to obtain a “gold standard” for the identification of stenoses causing ischaemia. Methods We enrolled 71 patients (52 male, 19 female; age mean 68.4±8.1 years) with chronic coronary syndrome or low-risk acute coronary syndrome without ST segment elevation who had at least a NIST and who had at least one vessel with a 50%-85% stenosis at ICA. iFR was measured in all coronary arteries with stenosis &amp;gt;50% and categorised according to the 0.89 threshold for ischaemia. Results iFR was assessed in 122 vessels. In a per-vessel analysis, in 56.7% ischaemia was present both at iFR and NIST, in 21.3% ischaemia was absent in both, while in 23.0% ischaemia was found at NIST but not confirmed by iFR. The overall accuracy of iFR with respect to NIST was 90.1%. However, when considering as the “gold standard” for coronary disease causing ischaemia the contemporary presence of an epicardial stenosis &amp;gt;70% at ICA and a positive NIST, the diagnostic accuracy of iFR greatly improved. The sensibility, specificity, PPV, NPV and accuracy were 96.5%, 75.0%, 73.3%, 96.7% and 84.4%, respectively. In case of discordance between NIST and iFR, revascularization was based on iFR. At a mean follow-up of 23±18 months, the composite endpoint of MACE (major adverse cardiac events, defined as the composite of all-cause death, nonfatal MI and unplanned coronary revascularization) occurred in 16.4%, while death/MI occurred in 11.9%. Stratification according to the per-patient concordance between iFR and NIST showed no significant differences in rates of MACE (p=0.50) and death/MI (p=0.20). Stratification based on iFR showed a higher death/MI rate in iFR-positive patients (11.9% vs. 0%, p=0.047) and a trend to higher MACE rate (11.9% vs. 4.47% p=0.14), Conclusions The diagnostic accuracy of iFR is low when compared with NIST as the reference for myocardial ischaemia, but it is very high when compared with the combined presence of epicardial stenosis and positive NIST. Therefore, iFR can accurately guide the decision to treat or defer revascularization of intermediate coronary stenoses, being most useful in patients with multivessel CAD and when non-invasive functional data are lacking or discordant with anatomy. Funding Acknowledgement Type of funding source: None

UK perspective on the changing landscape of non-invasive cardiac testing

ObjectiveTo document UK rates of exercise treadmill testing, functional stress testing and CT coronary angiography (CTCA). Specific aims were to determine how rates have changed in the context of changing...

Usefulness of Excellent Functional Capacity in Men and Women With Ischemic Exercise Electrocardiography to Predict a Negative Stress Imaging Test and Very Low Late Mortality

Exercise electrocardiography (ExECG) is widely employed to assess patients for coronary artery disease but it has limited diagnostic accuracy. Many patients with positive (ischemic) tests based on exercise-induced ST depression undergo secondary evaluation by noninvasive stress imaging. We hypothesized that high functional capacity in patients with positive ExECG could predict: (1) negative results in secondary evaluation by exercise echocardiography (ESE) or myocardial perfusion scintigraphy (MPS) and (2) low mortality on late follow-up. We evaluated 511 consecutive patients (312 men, 199 women; age 51 ± 9 years) referred for ESE or MPS after an ischemic ExECG at a treadmill workload of ≥10 metabolic equivalents. All-cause mortality was also obtained. Of 511 patients, 401 underwent ESE and 110 had MPS for secondary study. ESE was negative in 94% (376 of 401) and positive in 6% (25 of 401). MPS was also negative in 94% (103 of 110) and positive in 6% (7 of 110). Total stress imaging results were negative in 92% (286 of 312) of men and 97% (193 of 199) of women. During follow-up of approximately 6 years, there were 3 deaths with total all-cause mortality of 0.6% and average annual mortality of 0.1%. In conclusion, high functional capacity in patients with an ischemic ExECG predicts a negative ESE or MPS in a large majority of patients and very favorable late survival in both men and women. These results suggest that patients with ischemic ExECGs and a workload of ≥10 metabolic equivalents during ExECG may not require additional noninvasive or invasive evaluation.

Artificial neural network-based model enhances risk stratification and reduces non-invasive cardiac stress imaging compared to Diamond–Forrester and Morise risk assessment models: A prospective study

BackgroundCoronary artery disease (CAD) accounts for more than half of all cardiovascular events. Stress testing remains the cornerstone for non-invasive assessment of patients with possible or known CAD. Clinical utilization reviews show that most patients presenting for evaluation of stable CAD by stress testing are categorized as low risk prior to the test. Attempts to enhance risk stratification of individuals who are sent for stress testing seem to be more in need today. The present study compares artificial neural networks (ANN)-based prediction models to the other risk models being used in practice (the Diamond–Forrester and the Morise models). MethodsIn our study, we prospectively recruited patients who were 19 years of age or older, and were being evaluated for coronary artery disease with imaging-based stress tests. For ANN, the network architecture employed a systematic method, where the number of neurons is changed incrementally, and bootstrapping was performed to evaluate the accuracy of the models. ResultsWe prospectively enrolled 486 patients. The mean age of patients undergoing stress test was 55.2 ± 11.2 years, 35% were women, and 12% had a positive stress test for ischemic heart disease. When compared to Diamond–Forrester and Morise risk models, the ANN model for predicting ischemia provided higher discriminatory power (DP)(1.61), had a negative predictive value of 98%, Sensitivity 91% [81%-97%], Specificity 65% [60%-79%], positive predictive value 26%, and a potential 59% reduction of non-invasive imaging. ConclusionThe ANN models improved risk stratification when compared to the other risk scores (Diamond–Forrester and Morise) with a 98% negative predictive value and a significant potential reduction in non-invasive imaging tests.

Contrast-Enhanced Stress Echocardiography and Myocardial Perfusion Imaging in Patients Hospitalized With Chest Pain: A Randomized Study.

Ultrasound contrast-enhanced stress echocardiography improves endocardial visualization, but diagnostic test rates versus stress myocardial perfusion imaging (MPI) have not been studied. A prospective randomized trial was performed between April 2012 and October 2014 at a single-center, safety net hospital. Hospitalized patients referred for noninvasive stress imaging were randomized 1:1 to stress echocardiography or stress MPI. The primary outcome was diagnostic test rate defined as interpretable images and achievement of >85% of age-predicted maximal heart rate (for dobutamine and exercise). Rates were assessed among those completing testing and then based solely on image interpretability. Charges and length of stay were secondary outcomes. A total of 240 patients were randomized, and 229 completed testing. Diagnostic test rates were similar for stress echocardiography versus MPI {89.4% [95% confidence interval (CI), 82.2-94.4] vs. 94.8% [95% CI, 89.1-98.1], P = 0.13} and did not differ with multivariable adjustment. Modalities requiring a diagnostic heart rate criteria were more frequently ordered with stress echocardiography (100% vs. 26%; P < 0.001). Therefore, an imaging-based analysis without the 12 individuals who failed to achieve target heart rate (n = 217) was evaluated with diagnostic test rates of 100% versus 94.8% (95% CI, 89.1%-98.1%; P = 0.03) for stress echocardiography and MPI, respectively. Median length of stay did not differ. Median (interquartile range) test-related charges were lower with stress echocardiography: $2,424 ($2400-$2508) versus $3619 ($3584-$3728), P < 0.0001. Overall, tests were positive for ischemia in 8% of patients. In conclusion, contrast-enhanced stress echocardiography provides comparable diagnostic test rates to MPI with lower associated charges.

Routine preoperative testing in adults undergoing elective non-cardiothoracic surgery

The Belgian Health Care Knowledge Center (KCE) developed a guideline about routine preoperative testing in adults undergoing elective non-cardiothoracic surgery. The guideline is intended for all care providers involved in the preoperative and perioperative management (incl. anesthesiologists, surgeons, cardiologists, lung specialists, radiologists, clinical biologists, general practitioners, etc). A recent English guideline published by NICE (National Institute for Health and Care Excellence) was used as a starting point and adapted to the Belgian context. Clinical questions not included in the NICE guideline were developed de novo. The following tests are recommended under specific conditions: resting electrocardiogram, full blood count test, kidney function tests, haemostasis tests, urinalysis and urine culture, non-invasive cardiac stress imaging. The following tests are not routinely recommended: resting echocardiography, cardiopulmonary exercise testing, chest X-ray, polysomnography, lung function tests (including arterial blood gas analysis), glycated haemoglobin test, liver function tests, coronary CT angiography. This guideline supports clinicians in the choice of ad hoc preoperative testing based on the most recent evidence and specific history of their patients to ensure optimal quality and safety. Tools are provided with this guideline to improve daily usage.

Prognostic Value of Risk Factors, Calcium Score, Coronary CTA, Myocardial Perfusion Imaging, and Invasive Coronary Angiography in Kidney Transplantation Candidates

ObjectivesThis study sought to perform a prospective head-to-head comparison of the predictive value of clinical risk factors and a variety of cardiac imaging modalities including coronary artery calcium score (CACS), coronary computed tomography angiography (CTA), single-photon emission computed tomography (SPECT), and invasive coronary angiography (ICA) on major adverse cardiac events (MACE) and all-cause mortality in kidney transplantation candidates. BackgroundCurrent guidelines recommend screening for coronary artery disease in kidney transplantation candidates. Furthermore, noninvasive stress imaging is recommended in current guidelines, despite its low diagnostic accuracy and uncertain prognostic value. MethodsThe study prospectively evaluated 154 patients referred for kidney transplantation. All patients underwent CACS, coronary CTA, SPECT, and ICA testing. The clinical endpoints were extracted from patients’ interviews, patients’ records, and registries. ResultsThe mean follow-up time was 3.7 years. In total, 27 (17.5%) patients experienced MACE, and 31 (20.1%) patients died during follow-up. In a time-to-event analysis, both risk factors and CACS significantly predicted death, but only CACS predicted MACE. Combining risk factors with CACS identified a very-low-risk cohort with a MACE event rate of 2.1%, and a 1.0% mortality rate per year. Of the diagnostic modalities, coronary CTA and ICA significantly predicted MACE, but only coronary CTA predicted death. In contrast, SPECT predicted neither MACE nor death. ConclusionsCompared with traditional risk factors and other cardiac imaging modalities, CACS and coronary CTA seem superior for risk stratification in kidney transplant candidates. Applying a combination of risk factors and CACS and subsequently coronary CTA seems to be the most appropriate strategy. (Angiographic CT of Renal Transplantation Candidate Study [ACToR]; NCT01344434)

PROGNOSTIC VALUE OF CORONARY COMPUTED TOMOGRAPHY ANGIOGRAPHY, MYOCARDIAL PERFUSION IMAGING AND INVASIVE CORONARY ANGIOGRAPHY IN KIDNEY TRANSPLANTATION CANDIDATES: A PROSPECTIVE COHORT STUDY

Purpose: Current guidelines recommend screening for coronary artery disease in kidney transplantation candidates. Noninvasive stress imaging is preferred, despite low diagnostic accuracy and conflicting study results about the prognostic value. The aim of this study was to assess the predictive

005 Non-invasive stress imaging as a gatekeeper to complete revascularisation in stemi patients with moderate bystander disease at primary percutaneous coronary intervention

Introduction 40% of patients presenting with STEMI have multivessel disease (MVD). Current international guidelines recommend revascularisation of the culprit artery only. However recent trials (PRAMI/CVLPRIT) have shown a superiority of complete in-hospital revascularisation. Objective: Assess the role of non-invasive stress imaging as a gatekeeper to complete revascularisation in STEMI patients with moderate bystander disease. Methods A registry study of consecutive patients who underwent Primary Percutaneous Coronary Intervention (P-PCI) of the culprit artery. Significant MVD was defined as non-culprit stenosis ≥50% in large proximal epicardial vessel, or ≥75% elsewhere (moderate if 50–74% stenosis in large proximal epicardial vessel, or 75–94% elsewhere). Non-invasive stress imaging was performed at 4 weeks. Patients with severe or critical bystander disease were excluded from the study. A simple cost analysis model was built for UK and USA. Results 1,167 patients were included (74% males, 64 years), 33% demonstrating MVD. 40% of MVD underwent stress CMR, and 36% a stress echocardiogram. The remaining 93 patients underwent direct revascularisation or were lost to follow up. Only 47% had evidence of inducible myocardial ischaemia in moderate bystander coronary artery disease (61/157 in stress CMR and 78/141 in stress echocardiogram). When PCI in MVD is performed only in the presence of inducible myocardial ischemia, there is saving. (UK or US). Conclusions

012 Pre renal transplant cardiac risk stratification - clinical risk score to aid triage of patients prior to non-invasive or invasive evaluation

Introduction Stress myocardial perfusion imaging (MPI) is recommended to risk stratify patients undergoing renal transplantation. Patients with positive MPI studies are likely to need further invasive angiography. The aim of this study was to create a novel clinical risk score (CRS) to help triage patients to a single modality of non-invasive or invasive assessment prior to transplantation. Method A review of the risk factor profile of 39 patients undergoing stress MPI prior to renal transplantation was undertaken. The CRS was developed as follows (one point if present): Age >65​; BMI >30; Smoking​ history​; Hypertension; Diabetes; Vascular history. The CRS was applied to patients and compared with the outcome of the MPI. Results 20 male and 19 female patients were identified. 4 patients were excluded (incomplete data). 5 patients had positive MPI studies. The characteristics of patients with positive and negative MPI is in Table 1. The patient with a CRS score of zero had a negative MPI. 7.2% (26/28) of patients with a CRS of 1–3 had a positive stress MPI compared with 50% (3/6) in those with a CRS of 4 or greater. These patients required additional evaluation after MPI. Conclusion Patients with CRS of zero may not need non-invasive assessment prior to renal transplant. Patients with a CRS of 1–3 are best assessed by non-invasive stress imaging initially. In patients with CRS of 4 and greater, invasive angiography may be more appropriate as the single investigative modality. Larger studies are needed to validate these findings.

Myocardial Contrast Echocardiography has Favorable Sensitivity and Specificity for Coronary Artery Disease Diagnosis in Patients with LBBB: A Meta-Analysis

Background: Conflicting evidence exists on the ideal choice of non-invasive pharmacologic stress imaging for coronary artery disease (CAD) diagnosis in patients with left bundle branch block (LBBB). The aim of this meta-analysis is to compare data that examine the sensitivity and specificity of non-invasive pharmacologic stress imaging in patients with LBBB for obstructive CAD diagnosis. Methods: We performed a literature search in MEDLINE, embase.com and Cochrane (CENTRAL) without publication type or language restrictions. Both pharmacologic stress echocardiography (SE) and nuclear myocardial perfusion imaging (MPI) searches were restricted to the period between January 2004 and review time. Exclusion criteria included studies that lacked sensitivity and specificity data. The primary objective was to compare the sensitivities and specificities of all pharmacologic SE, MPI, myocardial contrast echocardiography (MCE), stress cardiac magnetic resonance (CMR) and positron emission tomography (PET) for identifying significant CAD in patients with LBBB. Results: 10 studies met the inclusion criteria for analysis. The sensitivity and specificity odds ratio of MCE was 92% (95% CI 81-97%), 93% (95% CI 86- 97%); Dobutamine (D)-CMR 64% (95% CI 42-82%), 94% (95% CI 85-98%); pharmacologic SE 73% (95% CI 55-86%), 84% (95% CI 75-91%); and pharmacologic MPI 83% (95% CI 72-91%), 56% (95% CI 42-70%). Conclusion: MCE and D-CMR appear to have improved diagnostic accuracy in comparison to pharmacologic SE and MPI in patients with LBBB. Additional MCE and D-CMR studies are warranted given their potential to become the non-invasive gold standard for the diagnosis of CAD in this population.

Limitations of Chest Pain Categorization Models to Predict Coronary Artery Disease

We aimed to evaluate how chest pain categorization, currently used to assess the pretest probability of coronary artery disease (CAD), predicts the actual presence of CAD in a population of patients with stable symptoms. We studied 475 consecutive patients enrolled in the Evaluation of Integrated Cardiac Imaging for the Detection and Characterization of Ischemic Heart Disease study based on possible symptoms of CAD. Chest pain or discomfort was categorized as typical angina, atypical angina, or as nonanginal according to the guidelines. Exertional dyspnea and fatigue suspected to be angina equivalents were classified as atypical angina. Patients with a probability of CAD <20 or >90% based on age, gender, and symptoms were excluded. The end points of this substudy were significant CAD (defined by invasive coronary angiography as >50% reduction in lumen diameter in the left main stem or >70% stenosis in a major coronary vessel or 30% to 70% stenosis with fractional flow reserve ≤0.8), inducible myocardial ischemia at noninvasive stress imaging, and their association. Patients' symptoms had limited ability to predict the presence of significant CAD, global chi-square being 5.0. The inclusion of age increased global chi-square to 18.7 and gender increased it further to 51.1. Using inducible myocardial ischemia or the association of CAD with inducible ischemia as end points, the ability to predict these end points was again better for patient demographics than for patient symptoms. Thus, the ability of current models based on symptoms, age, and gender to predict the presence of CAD is mainly based on patient demographics as opposed to symptoms.

Cardiac magnetic resonance myocardial perfusion reserve index is reduced in women with coronary microvascular dysfunction. A National Heart, Lung, and Blood Institute-sponsored study from the Women's Ischemia Syndrome Evaluation.

Women with signs and symptoms of ischemia and no obstructive coronary artery disease often have coronary microvascular dysfunction (CMD), diagnosed by invasive coronary reactivity testing (CRT). Although traditional noninvasive stress imaging is often normal in CMD, cardiac MRI may be able to detect CMD in this population. Vasodilator stress cardiac MRI was performed in 118 women with suspected CMD who had undergone CRT and 21 asymptomatic reference subjects. Semi-quantitative evaluation of the first-pass perfusion images was completed to determine myocardial perfusion reserve index (MPRI). The relationship between CRT findings and MPRI was examined by Pearson correlations, logistic regression, and sensitivity/specificity. Symptomatic women had lower mean pharmacological stress MPRI compared with reference subjects (1.71±0.43 versus 2.23±0.37; P<0.0001). Lower MPRI was predictive of ≥1 abnormal CRT variables (odds ratio =0.78 [0.70, 0.88], P<0.0001, c-statistic 0.78 [0.68, 0.88]). An MPRI threshold of 1.84 predicted CRT abnormality with sensitivity 73% and specificity 74%. Noninvasive cardiac MRI MPRI can detect CMD defined by invasive CRT. Further work is aimed to optimize the noninvasive identification and management of CMD patients. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00832702.

Meta-Analysis of Trials on Mortality After Percutaneous Coronary Intervention Compared With Medical Therapy in Patients With Stable Coronary Heart Disease and Objective Evidence of Myocardial Ischemia

Outcomes of percutaneous coronary intervention (PCI) versus medical therapy (MT) in the management of stable ischemic heart disease (SIHD) remain controversial, with some but not all studies showing improved results in patients with ischemia. We sought to elucidate whether PCI improves mortality compared to MT in patients with objective evidence of ischemia (assessed using noninvasive imaging or its invasive equivalent). We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing PCI to MT in patients with SIHD. To maintain a high degree of specificity for ischemia, studies were only included if ischemia was defined on the basis of noninvasive stress imaging or abnormal fractional flow reserve. The primary outcome was all-cause mortality. We identified 3 RCTs (Effects of Percutaneous Coronary Interventions in Silent Ischemia After Myocardial Infarction II, Fractional Flow Reserve versus Angiography for Multivessel Evaluation 2, and a substudy of the Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation trial) enrolling a total of 1,557 patients followed for an average of 3.0 years. When compared with MT in this population of patients with objective ischemia, PCI was associated with lower mortality (hazard ratio 0.52, 95% confidence interval 0.30 to 0.92, p=0.02). There was no evidence of study heterogeneity or bias among included trials. In this meta-analysis of published RCTs, PCI was shown to have a mortality benefit over MT in patients with SIHD and objective assessment of ischemia using noninvasive imaging or its invasive equivalent. In conclusion, this study provides insight into the management of a higher-risk SIHD population that is the focus of the ongoing International Study of Comparative Health Effectiveness with Medical and Invasive Approaches trial.

150 If an Agatston Score of Zero Means Neither Absence of Coronary Calcium nor Absence of Significant Disease, Should we be Following Nice Clinical Guidance 95?

IntroductionNICE Clinical Guidance 95 (March 2010) lays out a pathway for the investigation of chest pain incorporating more modern imaging modalities now spreading to most institutions. It suggests the use...