Diagnostic accuracy of multidetector computed tomography coronary angiography in 325 consecutive patients referred for transcatheter aortic valve replacement

    Diagnostic Accuracy of Multidetector Computed Tomography Coronary Angiography in 325 Consecutive Patients Referred for Transcatheter Aortic Valve Replacement Daniele Andreini MD, PhD, Gianluca Pontone MD, Saima Mushtaq MD, Antonio L. Bartorelli MD, Giovanni Ballerini MD, Erika Bertella MD, Chiara Segurini MD, Edoardo Conte MD, Andrea Annoni MD, Andrea Baggiano MD, Alberto Formenti MD, Laura Fusini MS, Gloria Tamborini MD, Francesco Alamanni MD, Cesare Fiorentini MD, Mauro Pepi MD PII: DOI: Reference:

S0002-8703(14)00356-1 doi: 10.1016/j.ahj.2014.04.022 YMHJ 4653

To appear in:

American Heart Journal

Received date: Accepted date:

8 November 2013 6 April 2014

Please cite this article as: Andreini Daniele, Pontone Gianluca, Mushtaq Saima, Bartorelli Antonio L., Ballerini Giovanni, Bertella Erika, Segurini Chiara, Conte Edoardo, Annoni Andrea, Baggiano Andrea, Formenti Alberto, Fusini Laura, Tamborini Gloria, Alamanni Francesco, Fiorentini Cesare, Pepi Mauro, Diagnostic Accuracy of Multidetector Computed Tomography Coronary Angiography in 325 Consecutive Patients Referred for Transcatheter Aortic Valve Replacement, American Heart Journal (2014), doi: 10.1016/j.ahj.2014.04.022

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Diagnostic Accuracy of Multidetector Computed Tomography Coronary Angiography

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CT coronary angiography in TAVR

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in 325 Consecutive Patients Referred for Transcatheter Aortic Valve Replacement.

Daniele Andreini MD, PhD, 1Gianluca Pontone MD, 1Saima Mushtaq MD, 1,2Antonio L. Bartorelli MD, 1Giovanni Ballerini MD, 1Erika Bertella MD, 1Chiara Segurini MD, 1Edoardo Conte MD, 1Andrea Annoni MD, 1Andrea Baggiano MD, 1Alberto Formenti MD, 1Laura Fusini MS, 1 Gloria Tamborini MD, 1,2Francesco Alamanni MD, 1,2Cesare Fiorentini MD, 1Mauro Pepi MD. 1

From the Centro Cardiologico Monzino, IRCCS Milan, Italy

the Department of Clinical Sciences and Community Health, Cardiovascular Section, University of Milan,

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Address for correspondence: Daniele Andreini, MD, PhD

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Centro Cardiologico Monzino

Via Parea 4 20138 Milan, Italy Tel: +39-02-58002577 Fax: +39-02-58002283

E-mail: [email protected]

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STRUCTURED ABSTRACT Background. Multidetector computed tomography (MDCT) provides detailed assessment of

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valve annulus and iliofemoral vessels in transcatheter aortic valve replacement (TAVR) patients.

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However, data on diagnostic performance of MDCT coronary angiography (MDCT-CA) are scarce. Aim of the study is to assess diagnostic performance of MDCT for coronary artery evaluation

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before TAVR

325 consecutive patients [234 without previous myocardial

Methods and Results.

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revascularization, 49 with previous coronary stenting and 42 with previous coronary artery bypass graft (CABG)] underwent invasive coronary angiography (ICA) and MDCT before TAVR. MDCTCA was performed using the same data set dedicated to standard MDCT aortic annulus evaluation. MDCT-CA evaluability and diagnostic accuracy in comparison with ICA as gold standard were

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assessed. The MDCT-CA evaluability of native coronaries was 95.6%. The leading cause of

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unevaluability was beam-hardening artifact due to coronary calcifications. In a segment-based analysis, MDCT-CA showed sensitivity, specificity, positive predictive value (PPV), negative

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predictive value (NPV) and accuracy for detecting ≥50% stenosis of 91%, 99.2%, 83.4%, 99.6%

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and 98.8%, respectively. The MDCT-CA evaluability of coronary stents was 82.1%. In a segmentbased analysis, MDCT-CA showed sensitivity, specificity, PPV, NPV and accuracy for detecting ≥50% in-stent restenosis (ISR) of 94.1%, 86.7%, 66.7%, 98.1% and 88.3%, respectively. All CABGs were correctly assessed by MDCT-CA. In a patient-based analysis, MDCT-CA showed sensitivity, specificity, PPV, NPV and accuracy of 89.7%, 90.8%, 80.6%, 95.4% and 90.5%, respectively. Conclusions. MDCT-CA allows to correctly ruling out the presence of significant native coronary artery stenosis, significant ISR and CABG disease in patients referred for TAVR. Key Words: Multidetector Computed Tomography; transcatheter aortic valve replacement ; invasive coronary angiography [Digitare il testo]

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INTRODUCTION

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Multidetector computed tomography coronary angiography (MDCT-CA) is currently considered a reliable diagnostic method for the evaluation of patients with known or suspected coronary artery

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disease (CAD) with high diagnostic performance for the detection of significant coronary stenosis (1), particularly in specific clinical subsets (2-4). Moreover, MDCT plays an increasingly critical

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role in patients scheduled for transcatheter aortic valve replacement (TAVR), providing detailed anatomic assessment of aorta and iliofemoral vessels and of the aortic root and valve annulus, including annulus diameters and area, valve leaflet length, degree of leaflet calcifications and distance between aortic annulus and coronary ostia (5,6). However, the diagnostic performance of

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MDCT-CA, that may be obtained using the same acquisition and data set employed with standard

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MDCT evaluation of the aortic annulus, has not been adequately investigated. Indeed, several factors may affect MDCT-CA evaluability and diagnostic accuracy in TAVR patients. Most of them

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are elderly with high prevalence of CAD and frequently present high heart rate (HR) at the time of

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scanning. Previous studies demonstrated that MDCT-CA evaluability and specificity is significantly reduced by a large atherosclerotic burden with diffuse calcifications of the coronary arteries and high HR during the scan, which may cause slice misalignment artifacts (7,8). Therefore, the aim of the present study was to assess the evaluability and diagnostic accuracy of MDCT-CA in comparison with invasive coronary angiography (ICA), as the gold standard imaging technique, in a large population of consecutive patients referred to our center for TAVR.

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METHODS Sources of funding. No extramural funding was used to support this work. The authors are solely

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responsible for the design and conduct of this study, all study analyses, the drafting and editing of

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the paper and its final contents.

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Study Population. Between January 2009 and September 2012, three-hundred and sixty-three consecutive patients with severe aortic stenosis (AS) undergoing ICA and cardiovascular MDCT

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within a TAVR screening protocol were considered for enrollment in this study. In all patients, ICA was performed 3  2 days after MDCT. Exclusion criteria were hypersensitivity to contrast agents (3 patients), impaired renal function (creatinine clearance <60 ml/min) (6 patients), inability to sustain a 15-s breath hold (8 patients) and cardiac arrhythmias (16 patients). According to the

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exclusion criteria, 330 patients were scheduled to undergo MDCT. In patients with a resting HR

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>70 bpm (211 patients, 64%), ivabradine (10 mg/day in patients with ≤70 Kg weight, 15 mg/day in patients with >70 Kg weight) was orally administered 48 to 72 hours before MDCT to achieve a

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target HR ≤70 bpm. Five patients were further excluded because the target HR was not reached. Therefore, a total of 325 patients were finally included in the study. The study protocol was

patients.

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approved by the institutional review board and written informed consent was obtained by all

Scan Protocol. All cardiovascular MDCT were performed with a LightSpeed VCT XTe Scanner (GE Healthcare, Milwaukee, WI), using a slice configuration of 64x0.625 mm and a gantry rotation time of 350 msec. For the chest, retrospective ECG triggering (temporal windows between 0% and 90% of the R wave to R wave time at 10% intervals of cardiac cycle) and a BMI–adapted scanning protocol were used: BMI<20 Kg/m2, tube voltage and tube current of 100 KVp and 500mA, respectively; 20≤BMI<25 Kg/m2, tube voltage and tube current of 100 KVp and 550mA, respectively; 25≤BMI<30 Kg/m2, tube voltage and tube current of 100 KVp and 600 mA, respectively; 30≤BMI<35 Kg/m2, tube voltage and tube current of 120 KVp and 650mA, [Digitare il testo]

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respectively. No ECG triggering was used for the abdomen and legs, with a delay between the 2 acquisitions of 5 seconds. Moreover, a post-processing algorithm called Adaptive Statistical

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Iterative Reconstruction was used instead of standard filtered back-projection algorithm to limit the

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expected increase of noise due to the low kilovoltage applied (9). The patients received a tripleinjection protocol of an 80-mL bolus of contrast (Iomeron 400 g/mL; Bracco, Milan, Italy) through

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an antecubital vein at an infusion rate of 5 mL/s, followed by 50 mL of saline solution and a further

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50-mL bolus of contrast at 3.5 mL/s.

MDCT-CA reconstruction and analysis. Data sets of each MDCT-CA were transferred to an image processing workstation (Advantage Workstation 4.4, Leonardo, GE Healthcare, Milwaukee, WI). Image reconstruction was retrospectively gated to the ECG including X-ray window between

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40 and 80% of the RR cycle using a 0.4-mm increment. Native coronary arteries were divided into

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16 segments according to the American Heart Association classification (10). Reconstructed images were evaluated by two readers blinded to the angiographic and clinical findings (D.A., G.P.) both

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with over 10 years of clinical experience in MDCT-CA performance and analysis. Image quality

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score was classified for each native coronary artery segment, stented segment and CABG as excellent (no artifacts, unrestricted evaluation), good (minor artifacts, good diagnostic quality), adequate (moderate artifacts, acceptable for routine clinical diagnosis), or poor/not evaluable (severe artifacts impairing accurate evaluation, segment classified as “unevaluable”) (11). The causes of impaired image quality of native coronary arteries or stented segments were classified as due to high-density artifacts generated by large coronary calcifications or metallic stent struts, motion artifacts related to non-compliance of breath hold or chest movement, misalignment of slices related to HR variation, high HR or premature ventricular beats during the scan and impaired signal/image noise ratio (11). The causes of impaired image quality of CABG imaging were classified as due to motion artifacts related to non-compliance of breath hold or chest movement, misalignment of slices related to related to HR variation, high HR or premature ventricular beats [Digitare il testo]

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during the scan, artifacts due to surgical metallic clips and impaired signal/image noise ratio. The two readers used transverse images and multiplanar reconstructions to classify each native coronary

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segment and graft on the basis of the presence of significant stenoses, defined as narrowings of the

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vascular lumen exceeding 50%, by visual estimation. Moreover, stented segments were screened for the presence of significant in-stent restenosis (ISR) (defined as ≥50% lumen diameter reduction) by

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visual assessment of intraluminal contrast density. For any disagreement in visual assessment and data analysis between the two readers, consensus agreement was achieved. Contrast density values

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in the aortic root and coronary arteries were recorded.

Invasive Coronary Angiography. Conventional ICA was performed by standard technique by two experienced operators (A.B and D.T.) both with over 20 years of clinical experience in ICA

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performance, blinded to the MDCT findings. The coronary arteries were classified according to the American Heart Association Classification (10). Angiograms were analyzed with quantitative

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coronary angiography software (QantCor, QCA, Pie Medical Imaging, Maastricht, the Netherlands)

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by 2 interventional cardiologists blinded to MDCT-CA results. The severity of coronary stenoses was quantified in 2 orthogonal planes, and a stenosis was classified as significant if the lumen

was recorded.

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diameter reduction was >50%. The dose of contrast agent (Iomeron 400 g/mL; Bracco, Milan, Italy)

Radiation dose parameters. The effective dose (ED) of MDCT was calculated according to the European Working Group for Guidelines on Quality Criteria in MDCT. The dose-length product (DLP), defined as total radiation energy absorbed by the patient’s body, was measured in mGy x cm in each patient. The ED was calculated as the DLP times a conversion coefficient for the chest (K= 0.014 mSv/mGy cm) and for abdomen (0.015 mSv/mGy cm). Statistical analysis. Statistical analysis was performed using the SPSS 13.0 software (SPSS Inc, Chicago, IL). Continuous variables were expressed as meanSD, and discrete variables as absolute numbers and percentages. Student’s t-test was used to test differences in continuous variables [Digitare il testo]

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between groups and Chi-squared test or Fisher’s exact tests were used to study differences regarding categorical data. The MDCT-CA evaluability (number of evaluable coronary segments,

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stented segments and grafts/total number of coronary segments, stented segments and grafts) of

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native coronary arteries, coronary stents and CABGs using a segment-based model was evaluated. Moreover, the MDCT-CA evaluability using a patient-based model (number of patients with at least

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one unevaluable segment/total number of patients) was measured. An estimation of diagnostic accuracy (sensitivity, specificity, positive predictive value [PPV], negative predictive value [NPV]

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and accuracy) was calculated on a segment-based model and on a patient-based model, based on a 50% threshold against the standard of ICA findings. On a patient-based analysis, patients with at least 1 detected stenosis >50% in a native coronary arteries or CABG or with at least 1 detected significant ISR were classified as “positive”. The 95% confidence intervals for all diagnostic

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accuracy parameters were calculated using the conventional binomial estimator method. The intra-

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observer and inter-observer variability for the detection of >50% coronary artery or graft stenosis and for the detection of significant ISR on MDCT-CA images were tested with Cohen’s Kappa. A P

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value <0.05 was considered statistically significant.

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RESULTS

Study population. Table 1 reports the patient clinical characteristics. We found a high prevalence of patients with hypertension (74%) and hypercholesterolemia (53%). Mean HR before oral administration of ivabradine was 75.110.5 bpm, whereas mean HR after ivabradine and before imaging was 61±9 bpm. MDCT-CA Diagnostic Accuracy. Table 2 reports a direct comparison of MDCT-CA findings and ICA results in patients without previous revascularization and with previous stenting or CABG MDCT-CA diagnostic accuracy in a segment-based analysis (using only evaluable native coronaries, stents and CABGs for analysis) showed a sensitivity, specificity, PPV, NPV and accuracy significantly higher for native coronary arteries (90,9%, 99.2%, 83.4%, 99.5% and 98.8%) [Digitare il testo]

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than for stents (94,1%, 86.6%, 66.6%, 98.1% and 88.3%). Similarly, MDCT-CA accuracy was significantly higher for CABGs (100%) than for stents. Moreover, PPV was significantly higher for

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CABGs than for native coronary arteries (100% vs. 83%). In a patient-based analysis, MDCT-CA

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showed sensitivity, specificity, PPV, NPV and accuracy of 89.7%, 90.8%, 80.6%, 95.4% and 90.5%, respectively. The Kappa value for detecting significant coronary artery stenosis and ISR

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with MDCT-CA was 0.91 and 0.85 for intra-observer agreement and 0.88 and 0.82 for interobserver agreement, respectively. The Kappa value for detecting significant CABG stenosis with

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MDCT-CA was 1 for both intra-observer and inter-observer agreements. Table 3 shows MDCT–CA accuracy by segments, using only evaluable segments of native coronaries. Contrast density in the aortic root and coronary arteries. Mean attenuation values in the aortic root and coronary arteries in our patients were: aortic root=570±140 Hounsfield Unit (HU), left

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main coronary artery=545±160 HU, left anterior descending coronary artery=494±150 HU , left

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circumflex coronary artery=495±152 HU, right coronary artery=460±162 HU.

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MDCT-CA evaluability and image quality. Using a segment-based analysis, the evaluability of native coronary arteries was 95.6% (4428/4633 coronary segments). The leading cause of

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unevaluability was the occurrence of beam-hardening artifacts due to large coronary calcifications (109 segments), followed by slice misalignments (56 segments) and motion artifacts (40 segments). No cases of impaired signal/image noise ratio were recorded. The evaluability of coronary stents was 81% (77/95 stent segments). The leading cause of unevaluability was the occurrence of beamhardening artifacts (17 segments), followed by slice misalignment (1 segments). No cases of motion artifacts or impaired signal/image noise ratio were recorded. The evaluability of native coronary arteries was significantly higher than that of stents. In regard to CABGs (38 left internal mammary arteries, 3 right internal mammary arteries, 63 vein grafts), MDCT-CA evaluability was 100%, with no significant artifacts recorded. CABG evaluability was significantly higher than that of native coronaries and stents. In a patient-based analysis of the 325 patients, 82 had at least one unevaluable [Digitare il testo]

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segment, with an overall evaluability of 74.7% (particularly, 68 patients had an unevaluable segment of native coronaries, 8 patients had an unevaluable stent, 6 patients had both a native

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coronary segment and a stented segment classified as unevaluable). Notably, among the 82 patients,

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in only 24 cases (corresponding to 7% of the overall population) the segment classified as unevaluable was a proximal or mid coronary segment. MDCT-CA image quality score of native

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coronaries, coronary stents and CABGs are reported in Table 4. The prevalence of segments classified as having excellent image quality was significantly higher for grafts than for native

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coronaries and stents. Figure 1 shows MDCT-CA case examples of patent arterial graft, and stents, severe stenosis of a native coronary artery and high-density artifact due to large coronary calcifications. Table 3 shows MDCT-CA accuracy by segments, using only evaluable segments of

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native coronaries Radiation and contrast agent dose.

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The mean radiation dose of MDCT for the assessment of valve annulus, iliofemoral vessels and

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coronary circulation was 22±4,2 mSv in patients with CABGs and 15±3,8 mSv in patients in whom stents and native coronary evaluation alone was required. The fixed MDCT-CA contrast dose was

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80 mL.The ICA mean contrast dose was 100±25 mL in patients with CABGs and 70±20 mL in patients in whom stents and native coronary evaluation alone was required.

DISCUSSION Aortic stenosis is the most common diagnosed valvular disease affecting nearly 5% of people aged >75 years. Surgical aortic valve replacement is the definitive treatment for symptomatic patients with severe AS (12,13). However, many elderly patients are not referred to surgery because of number and severity of coexisting illnesses (14). TAVR was introduced as an alternative treatment strategy in high-risk patients with AS and eleven years after the first implantation >50.000 procedures have been performed worldwide. Cardiovascular MDCT is playing an increasingly [Digitare il testo]

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critical role in patients scheduled to undergo TAVR, providing detailed anatomic assessment of aortic root, valve annulus and iliofemoral vessels, and determining appropriate coaxial angles to

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optimize the valve implantation procedure (5). Moreover, pre-procedural assessment of CAD and

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patency of CABG or previously implanted coronary stents is mandatory to stratify patient risk and to determine whether myocardial revascularization is indicated before TAVR. Previous studies

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demonstrated that MDCT-CA is accurate in evaluating native coronary arteries, coronary stents and CABGs (1,16,17), particularly in patients referred to heart valve surgery (3,18). However,

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MDCT-CA diagnostic performance may be limited in the elderly TAVR patients, due to the agerelated high atherosclerotic burden often with diffuse coronary calcifications and to the high HR at the time of scanning, frequently observed in severe AS patients. Indeed, it has been demonstrated that these factors may significantly impair MDCT-CA evaluability and specificity in the

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assessment of native coronary arteries (7,8,19). To the best of our knowledge, the present is the

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first study evaluating the diagnostic performance of MDCT-CA in a large population of consecutive patients referred for TAVR. The main finding is that MDCT-CA showed high

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evaluability and diagnostic accuracy for the assessment of native coronary arteries and CABGs,

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with excellent NPV even in a patient-based analysis. The evaluation of coronary stents demonstrated high NPV (98%) but a PPV of 67% and a moderate evaluability (81%). As concerns the evaluation of native coronaries, our study showed an overall MDCT-CA evaluability of 95.6% that is consistent with previous data regarding non-TAVR patients (20). The leading cause of unevaluability was the occurrence (109 cases) of beam-hardening artifacts due to large coronary calcifications. This was likely related to the high atherosclerotic burden of our study population, which is quite typical in elderly patients like ours whose mean age was 81 years. The second cause of unevaluability was slice misalignment (56 cases) related to HR variability, high HR or premature ventricular beats during the scan. The prevalence of this type of artifacts was relatively low (1.2%, 56/4633 coronary segments), which is surprising in severe AS patients who usually have high HR. It is noteworthy that the administration of oral ivabradine before the scan to all [Digitare il testo]

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patients with a resting HR >70 bpm (211 patients) achieved a mean HR at the time of imaging of 61 bpm, a value associated with excellent image quality in MDCT-CA. These results are in

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agreement with a previous study demonstrating the usefulness of ivabradine pretreatment in

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patients scheduled to undergo MDCT-CA [21]. Motion artifacts (40 cases), the third cause of unevaluability, was probably related to the age of the patients and their understandable inability to

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correctly sustain a breath hold during the scan. The MDCT-CA diagnostic accuracy and NPV in the evaluation of native coronary arteries were very high (98.8% and 99.5%, respectively) with a

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good but not excellent (83.4%) PPV. The latter value is probably due to the age-related high prevalence of significant CAD of study patients without previous myocardial revascularization (>50% coronary stenoses and multi-vessel disease were found in 45% and 49% of them, respectively) and to the high atherosclerotic burden of those with known CAD and previous

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stenting or CABG. As concerns coronary stent evaluation, we found an overall evaluability of 82%

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with 18 stents classified as unevaluable. High-density artifacts generated by metallic stent struts or large coronary calcifications were the leading cause of unevaluability (17 cases). Nevertheless, the

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diagnostic accuracy for stent evaluation was high (88.3%) and consistent with that reported in the

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literature in non-TAVR patients, with an excellent NPV of 98%. As regards the evaluation of surgical grafts, MDCT-CA confirmed an optimal diagnostic performance in our TAVR patients, showing evaluability and accuracy of 100%. The very high NPV observed in all three segmentsbased analyses (native coronary arteries, stents and CABGs) was confirmed also in the patientbased model, with a NPV of 95.4%. As concerns the clinical value of the present study, our data showed an overall MDCT-CA accuracy of 98.8% for the detection of >50% stenosis of native coronaries, which is consistent with previous data regarding non-TAVR patients in whom MDCT-CA is now considered a reliable and effective diagnostic method, such as those with mitral valve prolapse referred for surgical repair and patients with dilated cardiomiopathy with unknown etiology or patients with suspected CAD

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and intermediate likelihood for coronary artery disease (accuracy of 98% in the segment-based analysis in all studies) (2-4)

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These findings may have relevant clinical implications because they indicate that ICA could be

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avoided for the screening protocol of patients scheduled to undergo TAVR when MDCT-CA has ruled out the presence of significant coronary stenoses, ISR or CABG disease. Indeed, ICA could

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have been superfluous in 207 out of 325 patients of our study who were correctly classified as true negative by MDCT-CA. The routine use of MDCT-CA instead of ICA in TAVR patients may have

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several advantages. Indeed, coronary artery assessment by MDCT-CA may be performed with the same acquisition and data set employed for standard MDCT evaluation of the aortic annulus, avoiding further radiation exposure and, more importantly, additional administration of contrast agents, which is not negligible in ICA (70 mL for native coronary studies with additional 30 mL

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for CABGs evaluation) and similar to the amount that we used for MDCT-CA (80 mL). Repeated

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contrast administration before and during TAVR may be responsible for acute kidney injury that ranges from 12% to 28% after this procedure and is associated with a higher postoperative

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mortality (22). A major risk factor for this complication is pre-existing chronic kidney disease that

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ranges from 14% to 59% in elderly patients undergoing TAVR (23).

Limitations of the study. In interpreting these data, some limitations should be considered First, Ivabradine is not available in the US and this might limit the generalizibility of our study findings in non-european patients. Second, patients with severe renal insufficiency were excluded from the analysis given the high volume of medium contrast administered. Third, further advancements in MDCT technology are likely to overcome some drawbacks of the current MDCT generation. Particularly, the recent introduction of the newest generation dual-energy MDCT may reduce highdensity artifacts generated by large coronary calcifications (24), while the 320-detectors (25) or high-pitch (26) MDCT have the potential to significantly decrease motion artifacts.

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Conclusions. MDCT-CA allows to correctly ruling out the presence of significant coronary stenosis in patients referred for TAVR, demonstrating excellent NPV also in those previously treated with

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CABG or coronary stents.

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Andreini D, Pontone G, Mushtaq S, et al. Coronary in-stent restenosis: assessment with CT

coronary angiography. Radiology 2012;265:410-7.

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Andreini D, Pontone G, Mushtaq S, et al. Diagnostic performance of two types of low

radiation exposure protocol for prospective ECG-triggering multidetector computed tomography

Meijboom WB, Mollet NR, Van Mieghem CA, et al. Pre-operative computed tomography

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angiography in assessment of coronary artery bypass graft. Int J Cardiol. 2012;157:63-9.

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computed tomography coronary angiography: A randomized comparison of 7.5mg vs 5mg regimen.

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CT for quantitative imaging of myocardial perfusion. JACC Cardiovasc Imaging. 2012;5:829-36. [Digitare il testo]

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Rybicki FJ, Otero HJ, Steigner ML, et al. Initial evaluation of coronary images from 320-

detector row computed tomography. Int J Cardiovasc Imaging. 2008;24:535-46.

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for coronary CT angiography. J Cardiovasc Comput Tomogr. 2009;3:117-21.

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Figure Legend

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Figure 1.

Panel 1A. MDCT-CA volume rendering reconstruction showing the patency of LIMA anatomosed to LAD and proximal occlusion of two vein grafts (arrows). Panel 1B. MDCT-CA multiplanar reconstruction showing the patency of 4 stents implanted in the

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RCA.

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Panel 1C. Head-to-head comparison of MDCT-CA multiplanar reconstruction (upper panel) and

Panel 1D.

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ICA (lower panel) showing a severe stenosis on proximal LAD (arrows). MDCT-CA multiplanar reconstruction (left panel) showing high-density artifacts

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generated by large coronary calcifications impeding correct assessment of coronary lumen. No significant stenosis was observed with ICA (right panel) ICA= invasive coronary angiography; LAD= left anterior descending coronary artery; LIMA= left internal mammary artery; MDCT-CA= multidetector computed tomography coronary angiography; RCA= right coronary artery; SVG= safein vein graft.

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325

Patients without revascularizations, n

234

Patients with previous coronary stenting, n

49

Patients with previous CABG, n

42

Gender (male/female), n

132/194

SC

RI P

Number of patients, n

81.1 ± 6.6

BMI (Kg/m2), mean ± SD Serum creatinine (mg/dl), mean ± SD

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CARDIOVASCULAR RISK FACTORS Hypertension, n (%)

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Hypercholesterolemia, n (%)

Current smoking, n (%)

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Age (years), mean ± SD

Diabetes mellitus, n (%)

25.6  4.4 1.12  0.3

243 (74) 175 (53) 98 (30) 65 (20) 123 (37)

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Family history of CAD, n (%)

IVABRADINE

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Table 1. Baseline Characteristics

Number of patients, n (%)

211 (64)

Cumulative dose (mg), mean ± SD

25.8  12.4

Heart rate before Ivabradin (bpm), mean ± SD

75.1 10.5

Heart rate before imaging (bpm), mean ± SD

61.3  8.7*

PATIENTS WITHOUT REVASCULARIZATIONS Number

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234

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ACCEPTED MANUSCRIPT PATIENTS WITH PREVIOUS STENTING 49

Stent number

101

Stents per patient*

1,98±1,23

Drug eluting stent, n (%)

54 (53)

Bare-metal stent, n (%)

47 (46)

Nominal stent diameter (mm)*

3.14 ± 0.59

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Number

PATIENTS WITH PREVIOUS CABG Number

104

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CABG number

42

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BMI=Body Mass Index; CABG= coronary artery bypass-graft; CAD=coronary artery disease; SD=standard deviation;

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*: p <0.001 Heart rate before imaging vs. Heart rate before Ivabradine.

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Table 2. Comparison between MDCT-CA and ICA findings

ICA

p-value

Number

234

234

NS

Evaluable native coronary arteries segments, n

4428

4633

<0.001

Unevaluable segments, n

205

0

<0.001

4223

4416

NS

205

217

NS

49

49

-

77

95

<0.001

18

0

<0.001

Stent without ≥50% restenosis, n

53

54

NS

Stent with ≥50% in-stent restenosis, n

24

41

<0.01

42

42

-

CABG number

104

104

-

Patent CABG, n

81

81

-

≥50% stenosis CABG, n

5

5

-

Occluded CABG, n

18

18

-

Unevaluable CABG, n

0

0

-

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≥50% CAD segments, n

PATIENTS WITH PREVIOUS STENTING

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Number

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Segments without ≥50% CAD, n

Evaluable stents, n

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Unevaluable stents, n

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MDCT-CA

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PATIENTS WITHOUT REVASCULARIZATIONS

Number

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PATIENTS WITH PREVIOUS CABG

CAD=coronary artery disease; CABG=coronary artery bypass graft; ICA=invasive coronary angiography; NS=not significant.

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Table 3. Diagnostic accuracy of MDCT imaging in the 16 coronary artery segments of the 325 patients

Sp

NPV

PPV

Acc.

99.6%

100%

83.3%

99.6%

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Segment

TP

TN

FP

FN

Se

LM (306)

5

300

1

0

100%

Proximal (302)

23

272

6

1

Mid (304)

33

261

9

1

Distal (311)

4

305

1

1

D1 (280)

7

272

0

1

D2 (191)

1

190

100%

100%

100%

100%

100%

97%

96.6%

99.6%

78.5%

96.7%

80%

99.6%

99.6%

80%

99.3%

87.5%

100%

99.6%

100%

99.6%

0

100%

100%

100%

100%

100%

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Proximal (306)

16

Distal (299)

1

AC

LCX

PT

LAD

0

M1 (297)

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SC

(segments for analysis only; n = 4428)

284

5

1

94.1%

98.2%

99.6%

76.1%

98%

288

1

2

80%

99.6%

99.3%

88%

98.9%

9

281

1

6

60%

99.6%

97.9%

90%

97.6%

M2 (215)

1

214

0

0

100%

100%

100%

100%

100%

RI (118)

0

118

0

0

nc

100%

100%

nc

100%

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27

268

4

2

93.1%

98.5%

99.2%

87%

98%

Mid (294)

16

274

4

0

100%

98.5%

100%

80%

98.6%

Distal (311)

5

306

0

0

100%

100%

100%

100%

100%

PLA (294)

6

287

1

0

100%

99.6%

100%

85.7%

99.6%

PDA (299)

10

286

1

2

83.3%

99.6%

90.9%

98.9%

Total (4428)

171

4206

34

17

90.9%

99.1%

99.5%

83.4%

98.8%

SC

99.3%

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Proximal (301)

RI P

RCA

AC

CE

PT

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LM= left main coronary artery; LAD= left anterior descending coronary artery; D1= first diagonal branch; D2= second diagonal branch; LCx= left circumflex coronary artery, M1= first marginal branch; M2= second marginal branch; NC= not computable; RCA: right coronary artery; RI=intermediate branch; PDA= posterior descending artery; PPV= positive predictive value; NPV= negative predictive value.

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Excellent

Good

Adequate

Poor

n (%)

n (%)

n (%)

n (%)

4633

Stented segments

101

PT

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Native coronary artery segments

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N°

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Table 4. Comparison of image quality score in the three patient groups.

104

1867 (40) φ

1357 (29)

205 (5)Δ

21 (21)

25 (25)

37 (36)

18 (18)

70 (68)*

20 (19)

14 (13)†

0Ψ

AC

CE

CABG

1204 (26)

CABG=coronary artery bypass graft *: p <0.0001 CABG vs. Stented segments and vs. Native coronary arteries. Φ: p <0.001 Native coronary arteries vs. Stented segments and CABG. †: p < 0.0001 CABG vs. Stented segments and vs. Native coronary arteries. Ψ: p =0.02 CABG vs. Native coronary arteries and p<0.0001 CABG vs. Stented segments. Δ: p <0.0001 Native coronary arteries vs. Stented segments.

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