Detection Of Significant Coronary Artery Disease Research Articles

Diagnostic value of coronary flow reserve assessment by dynamic 99mTc-MIBI SPECT-CZT gamma camera for the detection of coronary artery disease

Abstract Background Coronary flow reserve (CFR) obtained by dynamic acquisition of myocardial blood flow using 99mTc-MIBI SPECT-CZT gamma camera may be useful to diagnose myocardial perfusion defects in patients with coronary artery disease (CAD). Purpose To assess the feasibility and diagnostic value of SPECT-derived CFR in patients with suspected of confirmed CAD. Methods The study group comprised 55 patients (pts) (43.6% females, mean age 64.6±8.4 years) with suspected CAD who were referred for scheduled coronary angiography. All pts underwent myocardial perfusion study with solid-state CZT nuclear camera (dipyridamole stress protocol) to calculate myocardial blood flow reserve. We measured total CFR, as well as CFR in three coronary territories: left anterior descending artery (LAD CFR), right coronary artery (RCA CFR) and left circumflex artery (LCx CFR). Results On coronary angiography 27 pts were found to have significant CAD (at least one major coronary artery ≥70% narrowed). Mean total CFR in pts with CAD was lower than in pts without CAD (1.73±0.59 vs 2.09±0.56, respectively, p=0.02). Similar differences were noted in LAD territory (1.47±0.57 vs 2.00±0.57; respectively, p=0.004) and RCA territory (1.55±0.54 vs 2.01±0.62; respectively, p=0.03). However, the differences in LCx CFR between CAD and no-CAD group did not reach statistical significance. Modest, but significant correlations were detected between LAD CFR and the percentage of LAD stenosis (r=−0.3; p=0.02). Total CFR has acceptable diagnostic value for detecting significant CAD (AUC=0.672; p=0.03). The criterion with the highest diagnostic accuracy was CFR <1.8 – its sensitivity was 63%, specificity 71.4%, and overall accuracy 67%. In analysis of coronary territories the highest diagnostic value was achieved for CFR LAD (AUC=0.744; p=0.007). Conclusions SPECT-derived CFR provides acceptable diagnostic accuracy for the detection of significant CAD. Funding Acknowledgement Type of funding sources: None.

Assessing myocardial perfusion in suspected coronary artery disease: rationale and design of the second phase 3, open-label multi-center study of flurpiridaz (F-18) injection for positron emission tomography (PET) imaging

BackgroundPositron emission tomography (PET) myocardial perfusion imaging (MPI) with the novel radiopharmaceutical Fluorine-18 Flurpiridaz has been shown in Phase 1, 2, and first Phase 3 clinical studies to be safe and effective in diagnosing coronary artery disease (CAD). We describe the methodology of the second FDA-mandated phase 3 prospective, open-label, international, multi-center trial of F-18 Flurpiridaz PET MPI. MethodsThe primary study end point is to assess the diagnostic efficacy of F-18 Flurpiridaz PET MPI in the detection of significant CAD [≥ 50% by quantitative invasive coronary angiography (ICA)] in patients with suspected CAD. The secondary endpoints are to evaluate the diagnostic efficacy of F-18 Flurpiridaz PET MPI compared to Tc-99 m-labeled SPECT MPI in the detection of CAD in all patients and in the following subgroups: (1) females; (2) patients with body mass index ≥ 30 kg/m2; and (3) diabetic patients. This trial’s design differs from the first phase 3 trial in that (1) comparison to SPECT is now a secondary end point; (2) patients with known CAD are excluded; and (3) both SPECT and PET MPI are performed before ICA. ConclusionsThis second phase 3 study will provide additional evidence on the diagnostic efficacy of F-18 Flurpiridaz PET MPI in the detection of significant CAD. Trial Registration Number:NCT03354273

The additional utility of two-dimensional strain in detection of coronary artery disease presence and localization in patients undergoing dobutamine stress echocardiogram.

Dobutamine stress echocardiogram (DSE) is a feasible and safe exercise-independent stress modality for diagnoses of coronary artery disease (CAD), but it is subjective, and operator dependant. Two-dimensional strain at peak stress could overcome these limitations and thus increase the accuracy of DSE. This was a prospective observational study in which 80 patients underwent DSE, two-dimensional strain at peak stress, and coronary angiography. Global longitudinal strains (GLS) cutoff point of -16.75 had 77.42% sensitivity and 83.33% specificity to detect significant CAD. Global circumferential strain (GCS) cutoff point of -20.75 had 93.55% sensitivity and 66.67% specificity to detect significant CAD (P=.003, areas under the curve [AUC]=0.73). The average territorial strain cutoff point for significant left anterior descending (LAD) lesion was -15.4 with 77.78% sensitivity and 82.86% specificity (P=.0001, AUC=0.78) and for non-LAD lesion was -16.9 with 82.93% sensitivity and 53.85% specificity (P=.0009, AUC=0.69). Two-dimensional strain at peak stress showed better agreement than DSE as regard number of vessels affected (K=0.579 vs 0.107), LAD lesion detection (K=0.783 vs 0.438), and non-LAD lesion detection (K=0.699 vs 0.233). Global longitudinal strain (GLS) at peak stress reduced DSE false positivity by 83%; the number of false-positive patients was reduced from 18 patients to only three patients. Two-dimensional strain at peak stress had an incremental value over DSE visual assessment/ wall-motion score index (WMSI) in reducing false-positive results of DSE. Two-dimensional strain at peak stress had greater accuracy than DSE alone not only in detection of significant CAD but also in detection of number of vessels with significant lesion as well as CAD localization.

Incremental diagnostic value of combined quantitative and qualitative parameters of magnetocardiography to detect coronary artery disease

Background/objectivesMagnetocardiography (MCG) has been proposed as a non-invasive and functional technique with high accuracy for diagnosis of myocardial ischemia. This study sought to investigate the incremental diagnostic value of combined quantitative and qualitative parameters of MCG to detect coronary artery disease (CAD). MethodsNinety six patients with suspected CAD who underwent coronary angiography were enrolled in the analysis to test the diagnostic accuracy of 2 MCG parameters (a quantitative parameter of the percent change of ST-segment fluctuation score and a qualitative parameter of non-dipole phenomenon). ResultsThe best cut-off value for the percent change of ST-segment fluctuation score was −51.0%. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were 78.1, 73.9, 82.0, 79.1, and 77.4, in the percent change of ST-segment fluctuation score and 86.5, 84.8, 88.0, 86.7, and 86.3 in non-dipole phenomenon. The area under the curve of receiver-operating characteristics was 0.79 for the percent change of ST-segment fluctuation score and 0.86 for non-dipole phenomenon (p<0.001). However, the incorporation of non-dipole phenomenon into a model with the percent change of ST-segment fluctuation score significantly improved C-statistics, indicating the enhancement of diagnostic performance in the detection of significant CAD (0.790 to 0.930; p<0.001). ConclusionsQualitative assessment of non-dipole phenomenon has a better diagnostic value than the quantitative parameter of percent change of ST-segment fluctuation score in the detection of significant CAD. Furthermore, this study found that the incorporation of non-dipole phenomenon into the percent change of ST-segment fluctuation score significantly improved the diagnostic performance of CAD detection.

Abstract 12746: Validation of a New Algorithm for Detection of Coronary Artery Disease Using Carotid and Femoral Vascular Ultrasound

Background: Atherosclerosis is a systemic disease and patients presenting with atherosclerotic coronary artery disease (CAD) usually have associated vascular disease and the reverse is true. Abdelwahab A. et al study is one of the studies who investigate the relation between the different duplex parameters of the carotid and femoral arteries and the extent of coronary atherosclerosis and they proposed a new algorithm for the detection of significant CAD by using carotid and femoral vascular ultrasound. Objective: To assess the validity and applicability of a new algorithm for detection of significant CAD. Methods: Peripheral arterial duplex evaluation was performed for 97 consecutive patients (65 men and 32 women; mean age 59±4.5 years) undergoing coronary angiography for a variety of indications. The following duplex parameters were determined in all patients : Common carotid and common femoral intima media thickness (IMT), carotid total plaques dimension product (PDP) and carotid-femoral (CARFEM) index which is a combination index of IMT of carotid artery and common femoral artery and total wall thickness of the superficial femoral artery. Results: As the number of affected coronary arteries increased, there was a proportional increase in the mean of Carotid IMT, total PDP and CARFEM Index (P= .025, &lt; 0.001 and 0.017 respectively ). Sensitivity, specificity, positive and negative predictive values of the proposed algorithm were 90.3% 72%, 90.3% and 72% respectively. Conclusion: Carotid and femoral duplex provides an easy non-invasive tool for detection of significant CAD. The proposed step-wise algorithm could be a reliable approach for detection of significant CAD.

Diagnostic Power of Longitudinal Strain at Rest for the Detection of Obstructive Coronary Artery Disease in Patients with Type 2 Diabetes Mellitus

Global longitudinal strain (GLS) measured by 2-D speckle-tracking echocardiography (2-D STE) at rest has been recognized as a sensitive parameter in the detection of significant coronary artery disease (CAD). However, the diagnostic power of 2-D STE in the detection of significant CAD in patients with diabetes mellitus is unknown. Two-dimensional STE features were studied in total of 143 consecutive patients who underwent echocardiography and coronary angiography. Left ventricular global and segmental peak systolic longitudinal strains (PSLSs) were quantified by speckle-tracking imaging. In the presence of obstructive CAD (defined as stenosis ≥75%), global PSLS was significantly lower in patients with diabetes mellitus than in patients without (16.65 ± 2.29% vs. 17.32 ± 2.27%, p < 0.05). Receiver operating characteristic analysis revealed that global PSLS could effectively detect obstructive CAD in patients without diabetes mellitus (cutoff value: –18.35%, sensitivity: 78.8%, specificity: 77.5%). However, global PSLS could detect obstructive CAD in diabetic patients at a lower cutoff value with inadequate sensitivity and specificity (cutoff value: –17.15%; sensitivity: 61.1%, specificity: 52.9%). In addition, the results for segmental PSLS were similar to those for global PSLS. In conclusion, global and segmental PSLSs at rest were significantly lower in patients with both obstructive CAD and diabetes mellitus than in patients with obstructive CAD only; thus, PSLSs at rest might not be a useful parameter in the detection of obstructive CAD in patients with diabetes mellitus.

Diagnostic accuracy of the core components of a multi-parametric cardiovascular magnetic resonance imaging protocol: a CE-MARC sub-study

Background The CE-MARC study was the largest prospective evaluation of the diagnostic accuracy of cardiovascular magnetic resonance (CMR) in coronary artery disease (CAD), demonstrating its superiority over single-photon emission computed tomography [1]. The trial adopted a multi-parametric protocol assessing ventricular function, myocardial perfusion, viability (with late gadolinium enhancement (LGE)) and coronary artery anatomy. There have been a number of previous studies analysing the diagnostic accuracy of different components of the CMR examination with contrasting results. We assessed the diagnostic accuracy of the individual components and selected combinations of the multi-parametric CMR examination from the CE-MARC study. Methods All patients from the CE-MARC population were studied. Visual CMR analyses were from the original, blinded read. Pre-specified sub-analysis of the four individual core components of the CMR protocol was performed in isolation, as a paired component (perfusion and LGE) and as a triplet (perfusion, LGE and ventricular function) and compared to the full multi-parametric protocol. Results Both CMR and X-ray angiography were available in 676 patients. The sensitivity of the combined CMR protocol was 86.5%, specificity 83.4%, PPV 77.2% and NPV 90.5%. The diagnostic accuracy of the individual components and paired and triplet combinations compared to the full multi-parametric protocol are presented in Table 1 and Figure 1. The maximum sensitivity for the detection of significant CAD by CMR was achieved when all four components were used. No individual component; paired perfusion with LGE; or perfusion with LGE and function significantly outperformed the multi-parametric protocol in terms of sensitivity. However in terms specificity, the individual components of perfusion, ventricular function and late gadolinium enhancement (LGE) all performed significantly better than the multi-parametric protocol (P < 0.0001). In addition, combining LGE with perfusion or with perfusion and ventricular function significantly improved the test specificity compared to the multi-parametric protocol (P < 0.0001 for each). In terms of PPV and NPV, the multi-parametric protocol performed significantly better than all individual components, paired or triplet combination. Conclusions A combined multi-parametric CMR protocol has higher sensitivity, PPV and NPV that the individual components however the specificity of the individual components of perfusion, ventricular function and late gadolinium enhancement (LGE) all performed significantly better than the multi-parametric protocol.

Comment on: Diagnostic accuracy of 320-slice computed tomography angiography for detection of coronary artery stenosis: Meta-analysis (Int J Cardiol 2013, http://dx.doi.org/10.1016/j.ijcard.2013.03.023)

We read with great interest the article “Diagnostic accuracy of 320-slice computed tomography angiography for detection of coronary artery stenosis: meta-analysis” by Li et al. [1]. The authors performed a meta-analysis of diagnostic accuracy of 320-slice coronary CT angiography (CCTA) in the diagnosis of coronary artery disease (CAD) based on an analysis of 10 studies available in the current literature. They concluded that 320-slice CCTA has similar diagnostic value to 64- and post-64 slice CT in the detection of significant CAD.

Is contrast-enhanced cardiac magnetic resonance imaging at 3 T superior to 1.5 T for detection of coronary artery disease?

The aim is to compare a compiled clinical routine cardiac magnetic resonance (CMR) imaging protocol performed at both 1.5 and 3 T in patients with suspected coronary artery disease (CAD) undergoing coronary X-ray angiography. CMR including adenosine perfusion and late gadolinium enhancement (LGE) at 1.5 T has been established for noninvasive detection of relevant CAD. However, little is known about the potential advantages of 3 T to detect CAD. Fifty-two evaluable patients (62.3 ± 10.2 years) were included into the study. All patients were scanned at both 1.5 and 3 T including adenosine stress and rest perfusion, and LGE imaging. CMR images were analyzed by two blinded readers in consensus. X-Ray angiography served as the reference method. A significant CAD was diagnosed by quantitative coronary analysis. Diagnostic accuracy of the combined analysis of perfusion and LGE imaging yielded better values at 1.5 and 3 T than the analysis of perfusion images alone. Specificity and sensitivity at 3 T was superior to 1.5 T in detecting coronary stenoses ≥50 % (90 vs. 75 % and 84.4 vs. 75 %) and ≥70 % (88 vs. 80 % and 96.3 vs. 88.9 %). This study showed that CMR at 3 T in a routine clinical setting is superior to 1.5 T in detection of significant CAD. 3 T might become the preferred CMR field strength for evaluation of CAD in clinical practice.

Evidence for prospective ECG-triggering coronary CT angiography in routine practice

Over the past decade, cardiac multidetector row CT (MDCT) has evolved, and the technology is poised to potentially alter the indications for diagnostic invasive coronary angiography (ICA) [1–10]. However, ionizing radiation concerns as related to increased cancer risks, initially applied to other organ systems [11, 12], have been translated to coronary CT angiography (CTA) and compared to ICA [13–17], while the dose dependent relation between low-radiation-dose exposure from cardiac procedures and subsequent risk of cancer has been reported [18]. Several strategies including ECG-triggered current modulation [19], lower tube voltage settings [13, 17, 20], and prospective ECG-triggering [21, 22] have progressively lowered patient radiation doses. One of the most applied approaches is prospective ECGtriggering [23, 24], where the exposure is confined to a predefined fraction of the time points of the cardiac cycle, rather than over the entire cycle. Depending on the details of the acquisition, the reduction in radiation dose can be as high as 80% [21, 22]. The effective dose of coronary CTA using prospective ECG-triggering (0.9–3.3 mSv) [2, 5] is comparable to, or lower than, diagnostic ICA (typical value of 7 mSv) [25]. However, there are unresolved concerns regarding diagnostic performance related to the limited phases of acquisition, and to date these methods have been most widely applied to patients with little risk of variations in cardiac cycle length and heart rates less than 70 beats per minute during the CT acquisition. In the current issue of the International Journal of Cardiovascular Imaging, Sun and Ng [26] performed a systematic review and meta-analysis of diagnostic value for coronary artery disease (CAD) using CTA with prospective ECG-triggering in comparison to ICA, and the authors also investigated the effective radiation dose. The 19 studies selected on primary selection criteria were reduced to fourteen that underwent the meta-analysis. Seven studies used singlesource 64-slice CT, four studies were performed with dual source 64-slice CT, two studies with 320-slice CT, and one with second generation of dual-source CT (128-slice). In 14 studies included in patient level (n = 910) analysis, pooled sensitivity for detection of significant CAD was 99% (95% CI: 98%, 100%) with specificity of 91% (95% CI: 88%, 94%) and the median negative predictive value (NPV) and positive predictive value (PPV) across studies were 94% (95% CI: 91%, 96%) and 99% (95% CI: 97%, 100%), respectively. Pooled positive (?LR) and negative (-LR) likelihood ratios were not reported at any of patient, vessel, or segment levels. Because observed heterogeneities were significant between 11 studies included in the vessel level (n = 3,531) and the segments level (n = 12,056) A. Salavati F. J. Rybicki (&) Applied Imaging Science Laboratory, Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, RA024, 75 Francis Street, Boston, MA 02115, USA e-mail: frybicki@partners.org

COMBINED NON-INVASIVE FUNCTIONAL AND ANATOMICAL DIAGNOSTIC WORK-UP IN CLINICAL PRACTICE: THE MAGNETIC RESONANCE AND COMPUTED TOMOGRAPHY IN SUSPECTED CORONARY ARTERY DISEASE (MARCC) STUDY

Aims The combined use of cardiac computed tomography (CT) coronary angiography (CTCA) and myocardial perfusion imaging allows the non-invasive evaluation of coronary morphology and function. Cardiovascular magnetic resonance (CMR) imaging has several advantages: it can simultaneously assess myocardial perfusion, ventricular and valvular function, cardiomyopathy, and aortic disease and does not involve any additional ionizing radiation. We investigated the combined use of cardiac CT and CMR for the diagnostic evaluation of patients with suspected coronary artery disease (CAD) in clinical practice. Methods and results A total of 192 patients with low or intermediate pre-test probability of CAD underwent CTCA and CMR. All patients with obstructive CAD on CTCA and/or myocardial ischaemia on CMR were referred for invasive coronary angiography (ICA). Fractional flow reserve was measured in case of intermediate lesions (30–70% diameter stenosis) on ICA. Additional cardiac and extra-cardiac findings by CTCA and CMR were registered. The combination of CTCA and CMR significantly improved specificity and overall accuracy (94 and 91%) for the detection of significant CAD compared with their use as a single technique (CTCA 39 and 57%, P < 0.0001; CMR 82 and 83%, P = 0.016). No events were recorded during follow-up (18 ± 6 months) in 104 patients who did not undergo ICA. Furthermore, the combined strategy provided an alternative diagnosis in 19 patients. Conclusion The combined use of CTCA and CMR significantly improved specificity and overall diagnostic accuracy for the detection of significant CAD and allowed the detection of alternative (extra-)cardiac disease in patients without significant CAD.

Cardiac magnetic resonance adenosine perfusion at 3 Tesla is superior to 1.5 Tesla for detection of relevant coronary artery stenosis

Background Cardiac magnetic resonance imaging (CMR) including adenosine perfusion and late gadolinium enhancement (LGE) at 1.5 Tesla (T) has been established for noninvasive detection of relevant coronary artery disease (CAD). However, little is known about the potential advantages of 3.0-T to detect CAD. The aim of our prospective study was to compare a compiled clinical routine CMR protocol performed at both 1.5-T and 3.0-T in patients with suspected CAD undergoing coronary x-ray angiography. Methods Fifty-two patients (62.3 ± 10.2 years) with suspected CAD referred for coronary x-ray angiography were included into the study. All patients were scanned at both 1.5-T and 3.0-T including functional imaging, adenosine stress and rest perfusion, and LGE imaging. CMR images were analyzed by two blinded readers in consensus. A significant CAD was diagnosed by quantitative coronary analysis. Two thresholds of >50% and >70% stenosis in coronary arteries with a diameter of >2mm were chosen. Results Diagnostic accuracy of the combined analysis of perfusion and LGE imaging yielded better values at 1.5-T and 3.0-T than the analysis of perfusion images alone. Sensitivity and specificity at 3.0-T was superior to 1.5-T in detection of coronary stenoses >50% (0.87 vs. 0.77 and 0.91 vs. 0.76) and >70% (0.96 vs. 0.89 and 0.92 vs. 0.80). Area under receiver-operator characteristic (ROC) curve was higher for detection of coronary stenoses in the left anterior descending and left circumflex artery at 3.0-T in comparison to 1.5-T, but not in the right coronary artery. Conclusions This study showed that CMR at 3.0-T in a routine clinical setting is superior to 1.5-T in detection of significant CAD. 3.0-T might become the preferred CMR field strength for evaluation of CAD in clinical practice.

MRI and CT in the diagnosis of coronary artery disease: indications and applications

In recent years, technical advances and improvements in cardiac computed tomography (CT) and cardiac magnetic resonance imaging (MRI) have provoked increasing interest in the potential clinical role of these techniques in the non-invasive work-up of patients with suspected coronary artery disease (CAD) and correct patient selection for these emerging imaging techniques. In the primary detection or exclusion of significant CAD, e.g. in the patient with unspecific thoracic complaints, and also in patients with known CAD or advanced stages of CAD, both CT and MRI yield specific advantages. In this review, the major aspects of non-invasive MR and CT imaging in the diagnosis of CAD will be discussed. The first part describes the clinical value of contrast-enhanced non-invasive CT coronary angiography (CTCA), including the diagnostic accuracy of CTCA for the exclusion or detection of significant CAD with coronary artery stenoses that may require angioplastic intervention, as well as potentially valuable information on the coronary artery vessel wall. In the second section, the potential of CT for the imaging of myocardial viability and perfusion will be highlighted. In the third and final part, the range of applications of cardiac MRI in CAD patients will be outlined.

Incremental Value of Adenosine-induced Stress Myocardial Perfusion Imaging with Dual-Source CT at Cardiac CT Angiography

First, to assess the feasibility of a protocol involving stress-induced perfusion evaluated at computed tomography (CT) combined with cardiac CT angiography in a single examination and second, to assess the incremental value of perfusion imaging over cardiac CT angiography in a dual-source technique for the detection of obstructive coronary artery disease (CAD) in a high-risk population. Institutional review board approval and informed patient consent were obtained before patient enrollment in the study. The study was HIPAA compliant. Thirty-five patients at high risk for CAD were prospectively enrolled for evaluation of the feasibility of CT perfusion imaging. All patients underwent retrospectively electrocardiographically gated (helical) adenosine stress CT perfusion imaging followed by prospectively electrocardiographically gated (axial) rest myocardial CT perfusion imaging. Analysis was performed in three steps: (a)Coronary arterial stenoses were scored for severity and reader confidence at cardiac CT angiography, (b)myocardial perfusion defects were identified and scored for severity and reversibility at CT perfusion imaging, and (c)coronary stenosis severity was reclassified according to perfusion findings at combined cardiac CT angiography and CT perfusion imaging. The sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of cardiac CT angiography before and after CT perfusion analysis were calculated. With use of a reference standard of greater than 50% stenosis at invasive angiography, all parameters of diagnostic accuracy increased after CT perfusion analysis: Sensitivity increased from 83% to 91%; specificity, from 71% to 91%; PPV, from 66% to 86%; and NPV, from 87% to 93%. The area under the receiver operating characteristic curve increased significantly, from 0.77 to 0.90 (P < .005). A combination protocol involving adenosine perfusion CT imaging and cardiac CT angiography in a dual-source technique is feasible, and CT perfusion adds incremental value to cardiac CT angiography in the detection of significant CAD.

Coronary Computed Tomography Angiography for Screening of an Asymptomatic Population: Too Much or Too Soon?

Coronary Computed Tomography Angiography for Screening of an Asymptomatic Population: Too Much or Too Soon?

Serum Fetuin-A and Mitral Annular Calcification As a New Predictors For Significant Coronary Artery Disease

Mitral annular calcification has been shown to be associated with atherosclerosis,and is a predictor of cardiovascular events. Fetuin-A has recently been described as aserum-based inhibitor of calcification. The present study was designed to evaluate thepredictive value of serum fetuin-A and mitral annular calcification in patients withsuspected/ diagnosed coronary artery disease. We prospectively studied fifty fourpatients with suspected/diagnosed coronary artery disease without renal impairmentor rheumatic valvular disease. The patients divided into 3 groups according to fetuin-A values. Group 1 low fetuin-A (32 patients). Group 2 normal fetuin-A (12 patients),group 3 fetuin-A high fetuin-A (10 patients). Full clinical examination, transthoracicechocardiography, coronary angiography, biochemical investigations offered to allpatients and fetuin-A level measured using EDI human fetuin-A ELISA kit. The resultsof the current study showed a higher incidence of mitral annular calcification amonggroup 1 (59.4%) in comparison to other groups, on other hand the same group hadlower left ventricular ejection fraction percent and higher incidence of restingregional wall motion abnormalities. Angiography showed a higher prevalence ofsevere coronary artery disease in patients with mitral annular calcification than thosewithout. Group 1 had, also higher prevalence of left main stenosis (43.1%vs 0%)P<0.05, and triple vessels disease (43.6%vs 13%) P<0.05. While the predictiveability of Mitral annular calcification in detection of significant coronary arterydisease was highly significant P= 0.0001. There was significant negative correlationbetween fetuin-A and hsCRP p<0.01and LDL-c p<0.05. One of the main findings isthe inverse association of serum fetuin-A concentration with Mitral annularcalcification as well as strong predictive value of both to presence of significantcoronary artery disease after multilogestic regression analysis. Conclusion: insymptomatic patients with suspected coronary artery disease, the presence of lowfetuin-A level and mitral annular calcification, may be considered as independentpredictors for the presence of significant obstructive coronary artery disease.

Diagnostic accuracy of quantitative cardiac MRI evaluation compared to stress single-photon-emission computed tomography

Cardiac MRI (cMRI) perfusion is a promising non-invasive tool to assess myocardial ischemia. The accuracy of quantitative cMRI perfusion has been recently demonstrated, but to date no previous study has compared this technique with stress single-photon-emission computed tomography (SPECT). The aim of this study was to evaluate the diagnostic accuracy of myocardial perfusion reserve (MPR) based on cMRI compared with SPECT. We examined 24 patients who underwent coronary angiography, stress SPECT and cMRI perfusion. Qualitative assessment of both SPECT and cMRI images, quantification of cMRI perfusion, and quantitative coronary angiography (QCA) were independently performed. MPR was calculated using Fermi deconvolution technique. Accuracy of quantitative and qualitative data was examined to detect > 50% diameter stenosis (DS) by QCA. Qualitative analysis was obtained in 198 segments and quantitative analysis was performed in 171 segments. Significant coronary artery disease (CAD) was present in 81.8% of patients. Visual cMRI assessment yielded sensitivity of 74.4% and specificity of 79.4% to predict > 50%DS, while SPECT showed sensitivity of 67.4% and specificity of 81.3%. The sensitivity for SPECT in the right coronary artery territory and apex was low compared to cMRI. Sensitivity and specificity for detection of significant CAD were 89.5% and 46.6% for MPR (cutoff 1.92). Area under the curve was 0.75 for MPR (P < 0.01). The diagnostic accuracy of qualitative examination of perfusion cardiac MRI and stress SPECT were comparable. The high sensitivity and low operator dependency of quantitative cMRI makes it an attractive tool to evaluate myocardial perfusion.

Automated assessment of myocardial SPECT perfusion scintigraphy: A comparison of different approaches of case-based reasoning

This study compared the diagnostic accuracy of different approaches of case-based reasoning (CBR) for the assessment of coronary artery disease (CAD) using thallium-201 myocardial perfusion scintigraphy in comparison with coronary angiography. For each scintigraphic image set, regional myocardial tracer uptake was obtained by polar map analysis. CBR algorithms based on a similarity measure were employed to identify similar scintigraphic images within the case library, where each case contained the scintigraphic data together with results of coronary angiography. The angiographic data of retrieved cases were then used to determine whether significant CAD was present in one of the major coronary arteries. Three different approaches of CBR were compared: (1) case retrieval based on a global comparison of polar map data (GLOB), (2) case retrieval based on a territorial comparison of polar map data (TER), and (3) case retrieval based on a comparison of a given case with eight sub-libraries classified according to the involvement of the three major coronary vessels using a group similarity measure (GROUP). Two matching algorithms the best-match approach and an adapted retrieving approach were combined with all three case retrieval methods and their influence on the diagnostic accuracy were investigated. For overall detection of significant CAD, the best-match approach of both TER and GROUP retrieval methods showed a higher diagnostic accuracy than the GLOB retrieval method (75% and 77% versus 70%, respectively). ROC analysis for the adapted retrieving approach showed a similar diagnostic accuracy for all three methods with an area under the curve of 0.79, 0.8, and 0.8 for GLOB, TER, and GROUP, respectively. The observed improvement in the diagnostic accuracy by the new approaches may lead to further improvements of CBR systems, which have the potential to offer valuable decision support for human readers, especially for less experienced investigators.

Thallium-201 scintigraphy after dipyridamole infusion with low level exercise. II. Quantitative analysis vs visual analysis

To determine the value and limitations of quantitative analysis of thallium-201 imaging after intravenous dipyridamole in combination with low level exercise, 81 patients with suspected coronary artery disease (CAD) were evaluated prospectively. The results of quantitative analysis were compared with the results of visual analysis. All patients underwent coronary arteriography and left ventricular angiography. Significant CAD was present in 59 patients (73%); multivessel CAD was observed in 33 patients (42%). Mild side-effects such as headache, vertigo and nausea were experienced by 12 patients (15%). To establish 'test-specific' normal limits in quantitative analysis of uptake and washout of thallium-201 after dipyridamole infusion with low level exercise we studied 20 healthy volunteers with a likelihood of CAD less than or equal to 1%. Sensitivity and specificity of quantitative analysis for overall detection of significant CAD were 76% and 73%, respectively vs 78% and 86%, respectively with visual analysis (P = NS). Sensitivity for the detection of multivessel CAD was slightly higher with quantitative analysis (73%) than with visual analysis (70%), but the specificity was lower (75% vs 92%) (P = NS). Sensitivity of quantitative analysis in relation to vessels involved was slightly lower than with visual analysis (RCA and LAD: P = NS; LCX: P less than 0.05). Of 14 patients with false-negative results, four had multivessel CAD. Thus, quantitative analysis after the combination of dipyridamole infusion with low level exercise did not improve the diagnostic value as assessed by semi-quantitative visual analysis.