Archive by Author

Feb201108

2

Heart Transplant Patient Outcomes: 5-Year Mean Follow-Up by Coronary Computed Tomography Angiography

Transplantation. 2011; 91(4):378-381

Rohnean A, Houyel L, Sigal-Cinqualbre A, Elfassy E, Paul JF

OBJECTIVES: We evaluate the feasibility and safety of coronary computed tomography angiography (CCTA) as the first-line investigation in heart transplant patients and the rate of coronary allograft vasculopathy detected using CCTA.

METHODS: From September 2003 to June 2009, we prospectively included 65 heart transplant recipients, retaining 62 who underwent yearly CCTA for coronary allograft vasculopathy detection (261 CCTAs). We used 16-slice, 64-slice, and 2×64-slice CT machines. Patients with coronary artery stenosis by CCTA had a confirmation and a further follow-up exclusively by conventional coronary angiography (CCA).

RESULTS: No major coronary events occurred during the study. Of the 62 baseline CCTAs, 37 (60%) were normal, 18 (29%) showed wall thickening, and 7 (11%) known significant stenosis, confirmed by CCA. The mean follow-up duration was 5 years. At the last follow-up, 26 (70%) patients with normal baseline findings remained normal, 9 (24%) had wall thickening, and 2 (6%) significant stenoses. Time to stenosis was consistently greater than 3 years. Of the 18 patients with initially wall thickening, 14 (78%) had wall thickening and 4 (22%) significant stenosis at last follow-up. The mean interval without any coronary lesion was 9.46±3.98 years. The mean interval without de novo significant stenosis was 10.31±4 years.

CONCLUSIONS: CCTA seems to be a safe noninvasive tool for monitoring heart transplant patients, and thus obviating the need for CCA. In patients with normal baseline CCTA, a 2-year interval between CCTAs may be safe.

PMID: 21297555

Jan201130

3

Features of Disrupted Plaques by Coronary CT Angiography: Correlates with Invasively-Proven Complex Lesions

Circ Cardiovasc Imaging. 2011; 4(1):347-348

Madder RD, Chinnaiyan KM, Marandici AM, Goldstein JA

OBJECTIVES: This study was designed as a “proof-of-concept” to establish whether CTA has the capability to identify morphologic features of plaque disruption.

METHODS: In patients with unstable angina undergoing CTA and invasive coronary angiography (ICA) within 30 days, quantitative CTA analysis was performed on all plaques for percent stenosis, volume, remodeling index, and volume of low attenuation plaque (LAP, <50 HU). Plaques >25% stenosis were evaluated for CTA features of disruption, including ulceration and intra-plaque dye penetration. Using ICA complex plaque as the reference standard for disruption, the sensitivity and specificity of ulceration and intra-plaque dye penetration by CTA were determined.

RESULTS: In 60 patients, 294 plaques were identified by CTA, of which 109 (37%) had features of disruption, including ulceration in 53 (18%) lesions and intra-plaque dye penetration in 80 (27%). Compared to non-disrupted lesions, plaques with ulceration or intra-plaque dye penetration by CTA were more voluminous (313 ± 356 mm(3) vs 118 ± 93 mm(3) p<0.0001), more often positively-remodeled (94.5% vs 44.3%, p<0.0001), contained more LAP (99 ± 161 mm(3) vs 19 ± 18 mm(3), p<0.0001), and were more often complex by ICA (57.8% vs 8.1%, p<0.0001). CTA features of disruption demonstrated modest to good sensitivity (53-81%), and good specificity (82-95%) for complex plaque by ICA.

CONCLUSIONS: In this highly selected group of patients with unstable angina, CTA can delineate features of plaque disruption, including ulceration and intra-plaque dye penetration, which are specific markers of invasively-identified complex plaque. Further studies are needed to confirm the generalizability of the results and to explore the clinical and prognostic implications of these findings.

PMID: 21262981

Jan201118

2

Long-Term Outcome and Impact of Surgery on Adults With Coronary Arteries Originating From the Opposite Coronary Cusp

Circulation. 2011; 123(2):154-162

Krasuski RA, Magyar D, Hart S, Kalahasti V, Lorber R, Hobbs R, Pettersson G, Blackstone E

OBJECTIVES: An anomalous coronary artery from the opposite sinus of Valsalva may increase sudden death risk in children and young adults, and surgical intervention is often recommended. The impact of this lesion when recognized in the adult and its management are ill defined.

METHODS: We reviewed 210, 700 cardiac catheterizations performed over a 35-year period at a single institution and identified 301 adults with an anomalous coronary artery from the opposite sinus of Valsalva, either anomalous right coronary artery from the left cusp or anomalous left main coronary artery from the right cusp. Patients were stratified by the pathway of the anomalous artery and the chosen treatment.

RESULTS: Among the 301 patients with anomalous coronary artery from the opposite sinus of Valsalva (0.14% of the cohort), 79% had anomalous right coronary artery from the left cusp, and 18% had an interarterial course (IAC). Patients with IAC were younger (52±13 versus 59±13 years; P=0.001) and more likely to undergo surgical intervention (52% versus 27%; P<0.001), but mortality was not increased with IAC. Among the 54 patients with IAC, 28 underwent surgical repair with no perioperative deaths. Patients evaluated since 2000 were significantly more likely to be referred for surgery (P=0.004). Surgical patients were more likely to have abnormal stress tests (90% versus 43%; P=0.01) and had more extensive atherosclerosis but less diabetes mellitus (0% versus 23%; P=0.01). Long-term survival at 10 years appeared similar in both groups.

CONCLUSIONS: In this single-center cohort study of patients with an anomalous coronary artery from the opposite sinus of Valsalva, surgical management appears to have been favored recently. Despite no perioperative mortality, a positive impact on long-term survival was not observed. The impact of surgery in older adults with anomalous coronary arteries arising from the opposite coronary sinus with IAC deserves further study.

PMID: 21200009

Jan201116

2

A Prospective Study for Comparison of MR and CT Imaging for Detection of Coronary Artery Stenosis

JACC Cardiovasc Imaging. 2011; 4(1):50-61

Hamdan A, Asbach P, Wellnhofer E, Klein C, Gebker R, Kelle S, Kilian H, Huppertz A, Fleck E

OBJECTIVES: The purpose of the present study was to directly compare the diagnostic accuracy of magnetic resonance imaging (MRI) and multislice computed tomography (CT) for the detection of coronary artery stenosis. Both imaging modalities have emerged as potential noninvasive coronary imaging modalities; however, CT-unlike MRI-exposes patients to radiation and iodinated contrast agent.

METHODS: One hundred twenty consecutive patients with suspected or known coronary artery disease prospectively underwent 32-channel 3.0-T MRI and 64-slice CT before elective X-ray angiography. The diagnostic accuracy of the 2 modalities for detecting significant coronary stenosis (≥50% luminal diameter stenosis) in segments ≥1.5 mm diameter was compared with quantitative invasive coronary angiography as the reference standard.

RESULTS: In the patient-based analysis MRI and CT angiography showed similar diagnostic accuracy of 83% (95% confidence interval [CI]: 75 to 87) versus 87% (95% CI: 80 to 92), p = 0.38; sensitivity of 87% (95% CI: 76 to 93) versus 90% (95% CI: 80 to 95), p = 0.16; and specificity of 77% (95% CI: 63 to 87) versus 83% (95% CI: 70 to 91), p = 0.06, respectively. All cases of left main or 3-vessel disease were correctly diagnosed by MRI and CT angiography. In the patient-based analysis MRI and CT angiography were similar in their ability to identify patients who subsequently underwent revascularization: the area under the receiver-operator characteristic curve was 0.78 (95% CI: 0.69 to 0.87) for MRI and 0.82 (95% CI: 0.74 to 0.90) for CT angiography.

CONCLUSIONS: Thirty-two channel 3.0-T MRI and 64-slice CT angiography similarly identify significant coronary stenosis in patients with suspected or known coronary artery disease scheduled for elective coronary angiography. However, CT angiography showed a favorable trend toward higher diagnostic performance.

PMID: 21232704

Dec201026

3

Prevalence of Subclinical Atherosclerosis in Asymptomatic Patients With Low-to-Intermediate Risk by 64-Slice Computed Tomography

Coron Artery Dis. 2011; 22(1):18-25

Iwasaki K, Matsumoto T, Aono H, Furukawa H, Samukawa M

OBJECTIVES: Recent research has shown that cardiovascular risk scoring significantly underestimates or misclassifies risk in key subsets of the population. There is a growing need for a noninvasive imaging to detect a subclinical atherosclerosis. Thus we hypothesized that 64-slice computed tomography (CT) could effectively detect subclinical atherosclerosis in asymptomatic patients with low-to-intermediate risk.

METHODS: Four hundred and fifteen asymptomatic patients with coronary risk factors underwent 64-slice CT. When 64-slice CT showed a significant stenosis we recommended that patients receive stress myocardial perfusion imaging (MPI). When MPI showed ischemic findings, we recommended that patients receive a coronary revascularization procedure. We followed our patients for a mean of 2.8 years (2.4-3.3 years).

RESULTS: We detected coronary plaques in 295 patients (71.1%). Of 135 patients with a negative scan for coronary calcification, noncalcified plaques were detected in 15 patients (11.1%). Two hundred and thirty-five patients (79.7%) had multiple plaques and, on average, one patient had 4.6 plaques. Significant coronary stenosis was detected in 91 patients (21.9%) and 85 patients underwent stress MPI. Myocardial ischemia was found in 27 patients (31.8%) and 21 patients underwent percutaneous coronary intervention. For a mean follow-up period of 2.8 years, four patients developed acute coronary syndrome.

CONCLUSIONS: Our results showed that the prevalence of subclinical atherosclerosis in asymptomatic patients with low-to-intermediate risk was very high and one-fifth of them had significant stenosis as shown by 64-slice CT. However, myocardial ischemia was detected in only one-third of them.

PMID: 21160291

Dec201021

8

Evaluation of Right Ventricular Function by 64-Row CT in Patients With Chronic Obstructive Pulmonary Disease and Cor Pulmonale

Eur J Radiol. 2010; 76(3):547-549

Gao Y, Du X, Liang L, Cao L, Yang Q, Li K

OBJECTIVES: The aim of this study was to investigate the clinical application value of right ventricle (RV) function measured by 64 multi-detector row CT (MDCT) in patients with chronic obstructive pulmonary disease (COPD) and cor pulmonale.

METHODS: Sixty-three consecutive patients with COPD and cor pulmonale were referred for electrocardiographically gated MDCT for evaluation of suspected or known coronary artery disease. Magnetic resonance imaging (MRI) for cardiac function analysis was performed on the same day. The MDCT and MRI examinations were successfully completed in 58 patients. Forty-six patients with COPD were divided into three groups according to the severity of disease by the pulmonary function test (PFT). Twelve patients diagnosed as cor pulmonale and 32 control subjects were also included. The RV function and myocardial mass (MM) were obtained by 64-MDCT and 1.5T cardiac MRI in all of the groups. The results were compared among the groups using the Newman-Keuls method. Pearson’s correlation was used to evaluate the relationship between the right ventricular ejection fraction (RVEF) and MM with the PFT results in COPD and cor pulmonale patients.

RESULTS: The RVEF was significantly lower in patients with severe COPD and cor pulmonale than it was in those patients with mild or moderate COPD (P<0.01). There were strong correlations between MDCT and MRI (r=0.826 for RV MM, r=0.982 and 0.969 for RV EDV and RV ESV, r=0.899 for RVEF) and between MDCT results and forced expiratory volume in 1s (r=0.787 for RVEF, r=-0.774 for RV MM) in all patients.

CONCLUSION: MDCT can accurately quantify RV function and MM. The RVEF and RV MM measured by MDCT correlate well with the severity of disease as determined by PFT in patients with COPD and cor pulmonale. The assessment of right ventricular function is clinically important for evaluation of the severity of COPD, which may provide an objective basis for therapeutic strategy.

PMID: 21112711

Dec201009

3

Multislice Computed Tomography for Prediction of Optimal Angiographic Deployment Projections During Transcatheter Aortic Valve Implantation

JACC Cardiovasc Intv. 2010; 3(11):1157-1165

Gurvitch R, Wood DA, Leipsic J, Tay E, Johnson M, Ye J, Nietlispach F, Wijesinghe N, Cheung A, Webb JG

OBJECTIVES: This study assessed whether multislice computed tomography (MSCT) could predict optimal angiographic projections for visualizing the plane of the native valve and facilitate accurate positioning during transcatheter aortic valve implantation (TAVI). Accurate device positioning during TAVI depends on valve deployment in angiographic projections perpendicular to the native valve plane, but these may be difficult to determine.

METHODS: Twenty patients underwent MSCT before TAVI. Using a novel technique, multiple angiographic projections accurately representing the native valve plane in multiple axes were determined. The accuracy of all predicted projections was determined post-procedure using angiography according to new criteria, based on valve perpendicularity and the degree of strut overlap (defined as excellent, satisfactory, or poor). The accuracy of valve deployment using MSCT was compared with the results of 20 consecutive patients undergoing TAVI without such MSCT angle prediction.

RESULTS: Correct final deployment projections were more frequent in the MSCT-guided compared with non-MSCT-guided group: excellent or satisfactory projections (90% vs. 65%, p = 0.06). The MSCT angle prediction was accurate but dependent on optimal images (optimal images: 93% of predicted angles were excellent or satisfactory, suboptimal images: 73% of predicted angles were poor). A “line of perpendicularity” could be generated with optimal projections across the right-to-left anterior oblique plane by adding the correct cranial or caudal angulation.

CONCLUSIONS: Pre-procedural MSCT can predict optimal angiographic deployment projections for implantation of transcatheter valves. An ideal deployment angle curve or “line of perpendicularity” can be generated. Understanding and applying these principles improves the accuracy of valve deployment and may improve outcomes.

PMID: 21087752

Nov201028

4

Individualized Assessment of Radiation Dose in Patients Undergoing Coronary Computed Tomographic Angiography With 256-Slice Scanning

Circulation. 2010; 122(21):1033-1034

Perisinakis K, Seimenis I, Tzedakis A, Papadakis AE, Damilakis J

OBJECTIVES: Available data on the radiation burden from coronary computed tomography (CT) angiography (CCTA) are mostly limited to effective dose estimates. This study provides individualized estimates of doses and associated life attributable risks of radiation-induced cancer in a clinical patient population undergoing 256-slice CCTA.

 METHODS: Typical retrospectively and prospectively ECG-gated CCTA exposures in a 256-slice CT scanner were simulated on 52 patient-specific voxelized phantoms. Dose images depicting the dose deposition on the exposed region were generated, and normalized organ doses for all primarily irradiated radiosensitive organs were derived and correlated to patient body habitus. Lung, breast, and esophagus absorbed doses were then determined in 136 consecutive patients subjected to CCTA. Projected life attributable risks of radiation-induced cancer were estimated through the use of appropriate sex-, age- and organ-specific cancer risk factors and compared with corresponding nominal cancer risks. The total projected life attributable risk of radiogenic cancer after CCTA decreases steeply with age at exposure, and lung cancer constitutes the most probable detriment for both sexes.

RESULTS: The relative risks of lung cancer associated with prospectively ECG-gated CCTA were 1.0032 and 1.0008 for women and men, respectively. The mean total projected life attributable risks were estimated to be 24.9±7.4 and 71.5±30.0 per 100 000 women undergoing prospectively and retrospectively ECG-gated CCTA, respectively. The corresponding values for men were 7.3±1.3 and 31.4±5.0 per 100 000 patients.

CONCLUSIONS: The mean projected life attributable risks of radiation-induced cancer in a typical clinical patient cohort undergoing standard prospectively ECG-gated CCTA with a 256-slice scanner were found to inconsequentially increase the natural cancer incidence rates.

PMID: 21098451

Nov201022

2

Bisphosphonate Use and Prevalence of Valvular and Vascular Calcification in Women MESA (The Multi-Ethnic Study of Atherosclerosis)

J Am Coll Cariol. 2010; 56(21):1752-1759

Elmariah S, Delaney JA, O'Brien KD, Budoff MJ, Vogel-Claussen J, Fuster V, Kronmal RA, Halperin JL.

OBJECTIVES: The aim of this study was to determine whether nitrogen-containing bisphosphonate (NCBP) therapy is associated with the prevalence of cardiovascular calcification. Cardiovascular calcification correlates with atherosclerotic disease burden. Experimental data suggest that NCBP might limit cardiovascular calcification, which has implications for disease prevention.

METHODS: The relationship of NCBP use to the prevalence of aortic valve, aortic valve ring, mitral annulus, thoracic aorta, and coronary artery calcification (AVC, AVRC, MAC, TAC, and CAC, respectively) detected by computed tomography was assessed in 3,710 women within the MESA (Multi-Ethnic Study of Atherosclerosis) with regression modeling.

RESULTS: Analyses were age-stratified, because of a significant interaction between age and NCBP use (interaction p values: AVC p < 0.0001; AVRC p < 0.0001; MAC p = 0.002; TAC p < 0.0001; CAC p = 0.046). After adjusting for age; body mass index; demographic data; diabetes; smoking; blood pressure; cholesterol levels; and statin, hormone replacement, and renin-angiotensin inhibitor therapy, NCBP use was associated with a lower prevalence of cardiovascular calcification in women ≥65 years of age (prevalence ratio: AVC 0.68 [95% confidence interval (CI): 0.41 to 1.13]; AVRC 0.65 [95% CI: 0.51 to 0.84]; MAC 0.54 [95% CI: 0.33 to 0.93]; TAC 0.69 [95% CI: 0.54 to 0.88]; CAC 0.89 [95% CI: 0.78 to 1.02]), whereas calcification was more prevalent in NCBP users among the 2,181 women <65 years of age (AVC 4.00 [95% CI: 2.33 to 6.89]; AVRC 1.92 [95% CI: 1.42 to 2.61]; MAC 2.35 [95% CI: 1.12 to 4.84]; TAC 2.17 [95% CI: 1.49 to 3.15]; CAC 1.23 [95% CI: 0.97 to 1.57]).

CONCLUSIONS: Among women in the diverse MESA cohort, NCBPs were associated with decreased prevalence of cardiovascular calcification in older subjects but more prevalent cardiovascular calcification in younger ones. Further study is warranted to clarify these age-dependent NCBP effects.

PMID: 21070928

Nov201020

3

Image Quality and Radiation Exposure With a Low Tube Voltage Protocol for Coronary CT Angiography Results of the PROTECTION II Trial

JACC Cardiovasc Imaging. 2010; 3(11):1113-1123

Hausleiter J, Martinoff S, Hadamitzky M, Martuscelli E, Pschierer I, Feuchtner GM, Catalán-Sanz P, Czermak B, Meyer TS, Hein F, Bischoff B, Kuse M, Schömig A, Achenbach S

OBJECTIVES: The purpose of this study was to evaluate image quality and radiation dose using a 100 kVp tube voltage scan protocol compared with standard 120 kVp for coronary computed tomography angiography (CTA). Concerns have been raised about radiation exposure during coronary CTA. The use of a 100 kVp tube voltage scan protocol effectively lowers coronary CTA radiation dose compared with standard 120 kVp, but it is unknown whether image quality is maintained.

METHODS: We enrolled 400 nonobese patients who underwent coronary CTA: 202 patients were randomly assigned to a 100 kVp protocol and 198 patients to a 120 kVp protocol. The primary end point was to demonstrate noninferiority in image quality with the 100 kVp protocol, which was assessed by a 4-point grading score (1 = nondiagnostic, 4 = excellent image quality). For the noninferiority analysis, a margin of -0.2 image quality score points for the difference between both scan protocols was pre-defined. Secondary end points included radiation dose and need for additional diagnostic tests during follow-up.

RESULTS: The mean image quality scores in patients scanned with 100 kVp and 120 kVp were 3.30 ± 0.67 and 3.28 ± 0.68, respectively (p = 0.742); image quality of the 100 kVp protocol was not inferior, as demonstrated by the 97.5% confidence interval of the difference, which did not cross the pre-defined noninferiority margin of -0.2. The 100 kVp protocol was associated with a 31% relative reduction in radiation exposure (dose-length product: 868 ± 317 mGy × cm with 120 kVp vs. 599 ± 255 mGy × cm with 100 kVp; p < 0.0001). At 30-day follow-up, the need for additional diagnostic studies did not differ (13.4% vs. 19.2% for 100 kVp vs. 120 kVp, respectively; p = 0.114).

CONCLUSIONS: A coronary CTA protocol using 100 kVp tube voltage maintained image quality, but reduced radiation exposure by 31% as compared with the standard 120 kVp protocol. Thus, 100 kVp scan protocols should be considered for nonobese patients to keep radiation exposure as low as reasonably achievable. (Prospective Randomized Trial on Radiation Dose Estimates of Cardiac CT Angiography in Patients Scanned With a 100 kVp Protocol

PMID: 21070998

Oct201031

2

Advanced Image Fusion to Overlay Coronary Sinus Anatomy with Real-Time Fluoroscopy to Facilitate Left Ventricular Lead Implantation in CRT

Pacing Clin Electrophysiol. 2010; 33(11):986-988

Duckett SG, Ginks MR, Knowles BR, Ma Y, Shetty A, Bostock J, Cooklin M, Gill JS, Carr-White GS, Razavi R, Schaeffter T, Rhode KS, Rinaldi CA

OBJECTIVES: Failure rate for left ventricular (LV) lead implantation in cardiac resynchronization therapy (CRT) is up to 12%. The use of segmentation tools, advanced image registration software, and high-fidelity images from computerized tomography (CT) and cardiac magnetic resonance (CMR) of the coronary sinus (CS) can guide LV lead implantation. We evaluated the feasibility of advanced image registration onto live fluoroscopic images to allow successful LV lead placement.

METHODS: Twelve patients (11 male, 59 ± 16.8 years) undergoing CRT had three-dimensional (3D) whole-heart imaging (six CT, six CMR). Eight patients had at least one previously failed LV lead implant. Using segmentation software, anatomical models of the cardiac chambers, CS, and its branches were overlaid onto the live fluoroscopy using a prototype version of the Philips EP Navigator software to guide lead implantation.

RESULTS: We achieved high-fidelity segmentations of cardiac chambers, coronary vein anatomy, and accurate registration between the 3D anatomical models and the live fluoroscopy in all 12 patients confirmed by balloon occlusion angiography. The CS was cannulated successfully in every patient and in 11, an LV lead was implanted successfully. (One patient had no acceptable lead values due to extensive myocardial scar.)

CONCLUSIONS: Using overlaid 3D segmentations of the CS and cardiac chambers, it is feasible to guide CRT implantation in real time by fusing advanced imaging and fluoroscopy. This enabled successful CRT in a group of patients with previously failed implants. This technology has the potential to facilitate CRT and improve implant success.

PMID: 21029135

Oct201022

3

Comparison of the Extent and Severity of Myocardial Perfusion Defects Measured by CT Coronary Angiography and SPECT Myocardial Perfusion Imaging

JACC Cardiovasc Imag. 2010; 3(10):1010-1019

Tamarappoo BK, Dey D, Nakazato R, Shmilovich H, Smith T, Cheng VY, Thomson LE, Hayes SW, Friedman JD, Germano G, Slomka PJ, Berman DS

OBJECTIVES: We compared electrocardiogram-gated computed tomography (CT) myocardial perfusion imaging (MPI) based on quantification of the extent and severity of perfusion abnormalities to that measured with single-photon emission computed tomography (SPECT) MPI. Contrast-enhanced CT-MPI has been used for the identification of myocardial ischemia.

METHODS: We performed CT-MPI during intravenous adenosine infusion in 30 patients with perfusion abnormalities on rest/adenosine stress SPECT-MPI acquired within 60 days (18 stress-rest CT-MPI and 12 stress CT-MPI only). The extent and severity of perfusion defects on SPECT-MPI were assessed on a 5-point scale in a standard 17-segment model, and total perfusion deficit (TPD) was quantified by automated software. The extent and severity of perfusion defects on CT-MPI was visually assessed by 2 observers using the same grading scale and expressed as summed stress score and summed rest score; visually quantified TPD was given by summed stress score/(maximal score of 68) and summed rest score/68. The magnitude of perfusion abnormality on CT-MPI in regions of the myocardium was defined.

RESULTS: On a per-segment basis, there was good agreement between CT-MPI and SPECT-MPI with a kappa of 0.71 (p < 0.0001) for detection of stress perfusion abnormalities. Automated TPD on SPECT-MPI was similar to visual TPD from CT-MPI (p = 0.65 stress TPD, and p = 0.12 ischemic TPD stress-rest) with excellent agreement (bias = -0.3 for stress TPD, and bias = 1.2 for ischemic TPD) on Bland-Altman analysis. Software-based quantification of the magnitude of stress perfusion deficit and ischemia on CT-MPI were similar to that for automated TPD measured by SPECT (p = 0.88 stress, and p = 0.48 ischemia), with minimal bias (bias = 0.6, and bias = 1.2).

CONCLUSIONS: Stress and reversible myocardial perfusion deficit measured by CT-MPI using a visual semiquantitative approach and a visually guided software-based approach show strong similarity with SPECT-MPI, suggesting that CT-MPI-based assessment of myocardial perfusion defects may be of clinical and prognostic value.

PMID: 20947046

Oct201004

1

Combined Presence of Aortic Valve Calcification and Mitral Annular Calcification as a Marker of the Extent and Vulnerable Characteristics of Coronary Artery Plaque assessed by 64-Multidetector Computed Tomography

Atherosclerosis. 2010; 212(1):70-77

Utsunomiya H, Yamamoto H, Kunita E, Kitagawa T, Ohashi N, Oka T, Yamazato R, Horiguchi J, Kihara Y

OBJECTIVE: We examined the association of aortic valve calcification (AVC) and mitral annular calcification (MAC) to coronary atherosclerosis using 64-multidetector computed tomography (MDCT). Valvular calcification is considered a manifestation of atherosclerosis. The impact of multiple heart valve calcium deposits on the distribution and characteristics of coronary plaque is unknown.

METHODS: We evaluated 322 patients referred for 64-MDCT, and assessed valvular calcification and the extent of calcified (CAP), mixed (MCAP), and noncalcified coronary atherosclerotic plaque (NCAP) in accordance with the 17-coronary segments model. We assessed the vulnerable characteristics of coronary plaque with positive remodeling, low-density plaque (CT density ≤38 Hounsfield units), and the presence of adjacent spotty calcification.

RESULTS: In 49 patients with both AVC and MAC, the segment numbers of CAP and MCAP were larger than in those with a lack of valvular calcification and an isolated AVC (p<0.001 for both). Multivariate analyses revealed that a combined presence of AVC and MAC was independently associated with the presence (odds ratio [OR] 9.36, 95% confidence interval [95%CI] 1.55-56.53, p=0.015) and extent (β-estimate 1.86, p<0.001) of overall coronary plaque. When stratified by plaque composition, it was associated with the extent of CAP (β-estimate 1.77, p<0.001) and MCAP (β-estimate 1.04, p<0.001), but not with NCAP. Moreover, it was also related to the presence of coronary plaque with all three vulnerable characteristics (OR 4.87, 95%CI 1.85-12.83, p=0.001).

CONCLUSIONS: The combined presence of AVC and MAC is highly associated with the presence, extent, and vulnerable characteristics of coronary plaque identified by 64-MDCT.

PMID: 20869714

Sep201012

3

Impaired Aortic Distensibility Measured by Computed Tomography is Associated With the Severity of Coronary Artery Disease

Int J Cardiovac Imaging. 2010; 4(2):119-126

Ahmadi N, Nabavi V, Hajsadeghi F, Flores F, Azmoon S, Ismaeel H, Shavelle D, Mao SS, Ebrahimi R, Budoff MJ

OBJECTIVES: Impaired aortic distensibility index (ADI) is associated with cardiovascular risk factors. This study evaluates the relation of ADI measured by computed tomographic angiography (CTA) with the severity of coronary atherosclerosis in subjects with suspected coronary artery disease (CAD).

METHODS: Two hundred and twenty-nine subjects,age 63 +/- 9 years, 42% female, underwent coronary artery calcium (CAC) scanning and CTA, and their ADI and Framingham risk score (FRS) were measured. End-systolic and end-diastolic (ED) cross-sectional-area(CSA) of ascending-aorta (AAo) was measured 15-mm above the left-main coronary ostium. ADI was defined as: [(Deltalumen-CSA)/(lumen-CSA in ED x systemic-pulse-pressure) x 10(3)]. ADI measured by 2D-trans-thoracic echocardiography (TTE) was compared with CTA-measured ADI in 26 subjects without CAC. CAC was defined as 0, 1-100, 101-400 and 400+. CAD was defined as luminal stenosis 0, 1-49% and 50%.

RESULTS: There was an excellent correlation between CTA- and TTE-measured ADI (r (2) = 0.94, P = 0.0001). ADI decreased from CAC 0 to CAC 400+; similarly from FRS 1-9% to FRS 20% + (P < 0.05). After adjustment for risk factors, the relative risk for each standard deviation decrease in ADI was 1.66 for CAC 1-100, 2.26 for CAC 101-400 and 2.32 for CAC 400+ as compared to CAC 0; similarly, 2.36 for non-obstructive CAD and 2.67 for obstructive CAD as compared to normal coronaries. The area under the ROC-curve to predict significant CAD was 0.68 for FRS, 0.75 for ADI, 0.81 for CAC and 0.86 for the combination (P < 0.05).

CONCLUSIONS: Impaired aortic distensibility strongly correlates with the severity of coronary atherosclerosis. Addition of ADI to CAC and traditional risk factors provides incremental value to predict at-risk individuals.

PMID: 20711815

Sep201005

2

ECG-Gated Dual-Source CT for Detection of Left Atrial Appendage Thrombus in Patients Undergoing Catheter Ablation for Atrial Fibrillation

J Interv Card Electrophysiol. 2010; 28(1):1123-1128

Kapa S, Martinez MW, Williamson EE, Ommen SR, Syed IS, Feng D, Packer DL, Brady PA

OBJECTIVES: Left atrial ablation is increasingly used to treat patients with symptomatic atrial fibrillation (AF). Prior to ablation, exclusion of left atrial appendage (LAA) thrombus is important. Whether ECG-gated dual-source computed tomography (DSCT) provides a sensitive means of detecting LAA thrombus in patients undergoing percutaneous AF ablation is unknown. Thus, we sought to determine the utility of ECG-gated DSCT in detecting LAA thrombus in patients with AF.

METHODS: A total of 255 patients (age 58 +/- 11 years, 78% male, ejection fraction 58 +/- 9%) who underwent ECG-gated DSCT and transesophageal echocardiography (TEE) prior to AF ablation between February 2006 and October 2007 were included. CHADS2 score and demographic data were obtained prospectively. Gated DSCT images were independently reviewed by two cardiac imagers blinded to TEE findings. The LAA was either defined as normal (fully opacified) or abnormal (under-filled) by DSCT.

RESULTS: An under-filled LAA was identified in 33 patients (12.9%), of whom four had thrombus confirmed by TEE. All patients diagnosed with LAA thrombus using TEE also had an abnormal LAA by gated DSCT. Thus, sensitivity and specificity for gated DSCT were 100% and 88%, respectively. No cases of LAA filling defects were observed in patients <51 years old with a CHADS2 of 0.

CONCLUSIONS: In patients referred for AF ablation, thrombus is uncommon in the absence of additional risk factors. Gated DSCT provides excellent sensitivity for the detection of thrombus. Thus, in AF patients with a CHADS2 of 0, gated DSCT may provide a useful stand-alone imaging modality.

PMID: 20809409

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