Archive by Author

Jun201124

2

Integrated SPECT/CT for Assessment of Haemodynamically Significant Coronary Artery Lesions in Patients With Acute Coronary Syndrome

Eur J Nucl Med Mol Imaging. 2011; 38(7):1243-1249

Rispler S, Aronson D, Abadi S, Roguin A, Engel A, Beyar R, Israel O, Keidar Z

OBJECTIVES: Early risk stratification in patients with non-ST elevation acute coronary syndromes (NSTE-ACS) is important since the benefit from more aggressive and costly treatment strategies is proportional to the risk of adverse clinical events. In the present study we assessed whether hybrid single photon emission computed tomography (SPECT)/coronary computed tomography angiography (CCTA) technology could be an appropriate tool in stratifying patients with NSTE-ACS.

METHODS: SPECT/CCTA was performed in 90 consecutive patients with NSTE-ACS. The Thrombolysis in Myocardial Infarction risk score (TIMI-RS) was used to classify patients as low- or high-risk. Imaging was performed using SPECT/CCTA to identify haemodynamically significant lesions defined as >50% stenosis on CCTA with a reversible perfusion defect on SPECT in the corresponding territory.

RESULTS: CCTA demonstrated at least one lesion with >50% stenosis in 35 of 40 high-risk patients (87%) as compared to 14 of 50 low-risk patients (35%; TIMI-RS <3; p <0.0001). Of the 40 high-risk and 50 (16%) low-risk TIMI-RS patients, 16 (40%) and 8 (16%), respectively, had haemodynamically significant lesions (p = 0.01). Patients defined as high-risk by a high TIMI-RS, a positive CCTA scan or both (n = 45) resulted in a sensitivity of 95%, specificity of 49%, PPV of 35% and NPV of 97% for having haemodynamically significant coronary lesions. Those with normal perfusion were spared revascularization procedures, regardless of their TIMI-RS.

CONCLUSIONS: Noninvasive assessment of coronary artery disease by SPECT/CCTA may play an important role in risk stratification of patients with NSTE-ACS by better identifying the subgroup requiring intervention.

PMID: 21688049

Jun201118

1

Cost-Effectiveness of Coronary Computed Tomography and Cardiac Stress Imaging in the Emergency Department a Decision Analytic Model Comparing Diagnostic Strategies for Chest Pain in Patients at Low Risk of Acute Coronary Syndromes

JACC Cardiovasc Imag. 2011; 4(5):549-556

Priest VL, Scuffham PA, Hachamovitch R, Marwick TH

OBJECTIVES: Emergency department presentations with chest pain are expensive and often unrelated to coronary artery disease (CAD). Coronary computed tomographic angiography (CTA) may allow earlier discharge of low-risk patients, resulting in cost savings.

METHODS: We modeled clinical and economic outcomes of diagnostic strategies in patients with chest pain and at low risk of CAD: exercise electrocardiography (ECG), stress single-photon emission computed tomography (SPECT), stress echocardiography, and a CTA strategy comprising an initial CTA scan with confirmatory SPECT for indeterminate results.

RESULTS: Our results suggest that a 2-step diagnostic strategy of CTA with SPECT for intermediate scans is likely to be less costly and more effective for the diagnosis of a patient group at low risk of CAD and a prevalence of 2% to 30%. The CTA strategies were cost saving (lower costs, higher quality-adjusted life-years) compared with stress ECG, echocardiography, and SPECT.

CONCLUSIONS: Confirming intermediate/indeterminate CTA scans with SPECT results in cost savings and quality-adjusted life-year gains due to reduced hospitalization of patients who returned false-positive initial CTA test. However, CTA may be associated with a higher event rate in negative patients than SPECT, and the diagnostic and prognostic information for the use of CTA in the emergency department is evolving. Large comparative, randomized, controlled trials of the different diagnostic strategies are needed to compare the long-term costs and consequences of each strategy in a population of defined low-risk patients in the emergency department.

PMID: 21565744

May201125

2

Assessment of Coronary Artery Remodelling by Dual-Source CT: A Head-To-Head Comparison With Intravascular Ultrasound

Heart. 2011; 97(12):991-997

Gauss S, Achenbach S, Pflederer T, Schuhbäck A, Daniel WG, Marwan M

OBJECITVES: While it is widely assumed that coronary CT angiography permits detection and quantification of ‘positive remodelling’ of coronary atherosclerotic lesions, there is a paucity of data comparing CT with established reference methods. Therefore, to assess the accuracy of dual-source CT for detecting positive versus absent or negative coronary artery remodelling of coronary atherosclerotic lesions as compared with intravascular ultrasound (IVUS).

METHODS: The datasets were evaluated of 38 patients referred for invasive coronary angiography and in whom an IVUS study of one coronary vessel was performed. Coronary CT angiography was performed within 24&emsp14;h before invasive coronary angiography. Using dual-source CT (Siemens Healthcare, Forchheim, Germany), a contrast-enhanced volume dataset was acquired (120&emsp14;kV, 400&emsp14;mA/rot, collimation 2×64×0.6&emsp14;mm, 60-80&emsp14;ml contrast agent, intravenous). IVUS was performed using a 40&emsp14;MHz IVUS catheter (Atlantis, Boston Scientific Corporation, Natick, Massachusetts, USA) and motorised pullback at 0.5&emsp14;mm/s. 48 corresponding non-calcified and partially calcified plaques within the coronary artery system were identified in both CT and IVUS using bifurcation points as fiducial markers. In CT datasets, multiplanar reconstructions orthogonal to the centre line of the coronary artery were rendered and cross-sectional vessel area was measured at the site of maximal narrowing as well as at a reference segment proximal to the lesion for each of the 48 plaques. The remodelling index (RI) was calculated by dividing the vessel area at the site of maximal narrowing by the area of the reference segment. Corresponding vessel areas and RIs were also determined in IVUS.

RESULTS: CT classified 41 plaques as positively remodelled (RI≥1.05) and seven as having either absent or negative remodelling (RI<1.05). In IVUS 29 plaques demonstrated positive remodelling, while 19 did not. Mean cross-sectional vessel areas measured by CT at the lesion and at the reference segment were 19±5&emsp14;mm(2) and 17± 5&emsp14;mm(2), respectively, versus 18±5&emsp14;mm(2) and 17±5&emsp14;mm(2) for IVUS (mean difference 1±2&emsp14;mm(2) and -0.2±1&emsp14;mm(2), p<0.0001 and 0.8, respectively). The mean RI in CT was significantly larger than in IVUS (1.2±0.2 vs 1.1±0.2, p<0.0001). Correlation between CT and IVUS was higher for vessel area measurements (r>0.9, p<0.0001) than for remodelling indices (r=0.7, p<0.0001) with Bland-Altman analysis showing a systematic overestimation of vessel areas and RI in CT. Interobserver agreement was moderate for CT and IVUS measurements. Receiver operating characteristic curve analysis showed that a RI of 1.1 in CT identified positively remodelled plaques in IVUS with a sensitivity of 83% and a specificity of 78% (area under the curve=0.8, 95% CI 0.7 to 1.0). Using the standard cut-off point of 1.05 to identify positively remodelled plaques in CT resulted in a sensitivity of 100%, and a specificity of 45%.

CONCLUSIONS: Coronary CT angiography allows analysis of coronary artery remodelling. The degree of positive remodelling is typically overestimated by CT. A threshold of 1.1 for the RI may be optimal to classify plaques as ‘positively remodelled’ in coronary CT angiography.

PMID: 21478387

May201121

1

Contrast Medium-Induced Acute Kidney Injury: Comparison of Intravenous and Intraarterial Administration of Iodinated Contrast Medium

J Vasc Interv Radiol. 2011; 22(5):692-702

Karlsberg RP, Dohad SY, Sheng R; Iodixanol Peripheral Computed Tomographic Angiography Study Investigator Panel

OBJECTIVES: To compare the incidence of contrast medium-induced acute kidney injury (AKI) after intravenous (IV) administration of iodixanol for computed tomographic (CT) angiography versus intraarterial (IA) injection of iodixanol or low osmolar contrast medium (LOCM) for digital subtraction angiography (DSA) within the same population suspected of peripheral arterial occlusive disease (PAOD).

METHODS:  CT angiography was performed with IV iodixanol 320 mgI/mL. After a washout period of 3-14 days, DSA was performed with IA iodixanol or LOCM. Serum creatinine was measured at baseline and 24 hours after administration. Contrast medium-induced AKI was defined by a serum creatinine increase of at least 25% versus baseline at 24 hours. Data were analyzed with χ(2) statistics.

RESULTS:  Mean baseline serum creatinine values were comparable between CT angiography with IV contrast medium and DSA with IA contrast medium (93.3 μmol/L ± 52.92 vs 92.8 μmol/L ± 61.70). The incidence of AKI for CT angiography after IV iodixanol administration was 7.6% (20 of 264), which was not statistically different than the 8.7% incidence (22 of 253) for DSA with IA iodixanol or LOCM (P = .641). In the 143 patients who received only iodixanol for both procedures, incidences of contrast medium-induced AKI were comparable after IV (7.0%) and IA (5.6%) administration (P = .626).

CONCLUSIONS:  The rates of contrast medium-induced AKI are not statistically different between IV iodixanol for CT angiography and IA iodixanol or another LOCM for DSA in the same population with suspected PAOD.

PMID: 21570871

Apr201111

3

The Lack of Growth in Use of Coronary CT Angiography: Is It Being Appropriately Used?

AJR Am J Roentgenol. 2011; 196(4):862-867

Levin DC, Parker L, Halpern EJ, Julsrud PR, Rao VM

OBJECTIVES: The purpose of this article is to study recent utilization trends in coronary CT angiography (CTA) and compare them with radionuclide myocardial perfusion imaging (MPI), a competing procedure.

METHODS: The nationwide Medicare Part B databases were used to determine utilization rates per 100,000 beneficiaries. Rates for coronary CTA were studied from 2006 (the first year Current Procedural Terminology codes were available for this procedure) through 2008. Rates for MPI were studied from 1998 through 2008. Medicare specialty codes were used to identify examinations done by radiologists and cardiologists.

RESULTS: The coronary CTA total utilization rate per 100,000 rose from 99 in 2006 to 210 in 2007 (112%) but then decreased to 193 in 2008 (-8%). The rate for MPI increased from 4748 in 1998 to a peak of 8753 in 2006 (84%), then declined to 8467 in 2008. Cardiologists performed the majority of both coronary CTA and MPI. In 2008, MPI was performed 44 times as often as coronary CTA.

CONCLUSIONS: Given that coronary CTA is a new procedure that has aroused much interest and has been shown to have very favorable results, the drop in its utilization rate in 2008 was surprising. A review of the literature indicates that there are shortcomings to the clinical diagnosis of coronary artery disease (which often includes the use of MPI), that coronary CTA can be used to stratify risk, and that it can expedite the workup of patients with acute chest pain in emergency departments. The evidence from the literature review suggests that both invasive coronary angiography and MPI may be overutilized, whereas coronary CTA is probably underutilized.

PMID: 21427337

Mar201124

1

Influence of Noninvasive Cardiovascular Imaging in Primary Prevention: Systematic Review and Meta-analysis of Randomized Trials

Arch Inern Med. 2011; 171(5):422-424

Hackam DG, Shojania KG, Spence JD, Alter DA, Beanlands RS, Dresser GK, Goela A, Davies AH, Badano LP, Poldermans D, Boersma E, Njike VY

OBJECTIVES: Despite extensive use in practice, the impact of noninvasive cardiovascular imaging in primary prevention remains unclear.

METHODS: We searched for randomized trials that compared imaging with usual care and reported any of the following outcomes in a primary prevention setting: medication prescribing, lifestyle modification (including diet, exercise, or smoking cessation), angiography, or revascularization.

RESULTS: Seven trials were included. Trials screened patients for inducible myocardial ischemia (2 trials), coronary calcification (3 trials), carotid atherosclerosis (1 trial), or left ventricular hypertrophy (1 trial). Imaging had no effect on medication prescribing overall (odds ratio [OR], 1.01; 95% confidence interval [CI], 0.76-1.33) or on provision of lipid-modifying agents (OR, 1.08; 95% CI, 0.58-2.01), antihypertensive drugs (OR, 1.05; 95% CI, 0.75-1.47), or antiplatelet agents (OR, 1.05; 95% CI, 0.84-1.32). Similarly, no effect was seen on dietary improvement (OR, 0.78; 95% CI, 0.22-2.85), physical activity (0.02 vs -0.08 point change for imaging vs control on a 5-point scale; P = .23), or smoking cessation (OR, 2.24; 95% CI, 0.97-5.19). Imaging was not associated with invasive angiography (OR, 1.26; 95% CI, 0.89-1.79).

CONCLUSIONS: We found limited evidence suggesting that noninvasive cardiovascular imaging alters primary prevention efforts. However, given the imprecision of these results, further high-quality studies are needed.

PMID: 21403010

Mar201116

1

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

Circ Cardiovasc Imaging. 2011; 4(2):105-113

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

Mar201113

6

Prospective Validation of Standardized, 3-Dimensional, Quantitative Coronary Computed Tomographic Plaque Measurements Using Radiofrequency Backscatter Intravascular Ultrasound as Reference Standard in Intermediate Coronary Arterial Lesions Results From the ATLANTA (Assessment of Tissue Characteristics, Lesion Morphology, and Hemodynamics by Angiography With Fractional Flow Reserve, Intravascular Ultrasound and Virtual Histology, and Noninvasive Computed Tomography in Atherosclerotic Plaques) I Study

JACC Cardiovasc Interv. 2011; 4(2):198-208

Voros S, Rinehart S, Qian Z, Vazquez G, Anderson H, Murrieta L, Wilmer C, Carlson H, Taylor K, Ballard W, Karmpaliotis D, Kalynych A, Brown C

OBJECTIVES: This study sought to determine the accuracy of 3-dimensional, quantitative measurements of coronary plaque by computed tomography angiography (CTA) against intravascular ultrasound with radiofrequency backscatter analysis (IVUS/VH).  Quantitative, 3-dimensional coronary CTA plaque measurements have not been validated against IVUS/VH.

METHODS: Sixty patients in a prospective study underwent coronary X-ray angiography, IVUS/VH, and coronary CTA. Plaque geometry and composition was quantified after spatial coregistration on segmental and slice-by-slice bases. Correlation, mean difference, and limits of agreement were determined.

RESULTS: There was significant correlation for all pre-specified parameters by segmental and slice-by-slice analyses (r = 0.41 to 0.84; all p < 0.001). On a segmental basis, CTA underestimated minimal lumen diameter by 21% and overestimated diameter stenosis by 39%. Minimal lumen area was overestimated on CTA by 27% but area stenosis was only underestimated by 5%. Mean difference in noncalcified plaque volume and percent and calcified plaque volume and percent were 38%, -22%, 104%, and 64%. On a slice-by-slice basis, lumen, vessel, noncalcified-, and calcified-plaque areas were overestimated on CTA by 22%, 19%, 44%, and 88%. There was significant correlation for percentage of atheroma volume (0.52 vs. 0.54; r = 0.51; p < 0.001). Compositional analysis suggested that high-density noncalcified plaque on CTA best correlated with fibrous tissue and low-density noncalcified plaque correlated with necrotic core plus fibrofatty tissue by IVUS/VH.

CONCLUSIONS: This is the first validation that standardized, 3-dimensional, quantitative measurements of coronary plaque correlate with IVUS/VH. Mean differences are small, whereas limits of agreement are wide. Low-density noncalcified plaque correlates with necrotic core plus fibrofatty tissue on IVUS/VH.

PMID: 21349459

Mar201108

1

Assessment of Left Ventricular Regional Wall Motion and Ejection Fraction With Low-Radiation Dose Helical Dual-Source CT: Comparison to Two-Dimensional Echocardiography

J Cardiovasc Comput Tomogr. 2011; 5(2):148-152

Nakazato R, Tamarappoo BK, Smith TW, Cheng VY, Dey D, Shmilovich H, Gutstein A, Gurudevan S, Hayes SW, Thomson LE, Friedman JD, Berman DS

OBJECTIVES: Electrocardiographic (ECG)-based tube current modulation during cardiac CT reduces radiation exposure but significantly increases noise in parts of the cardiac cycle where tube current is minimized. We evaluated the effect of maximal ECG-based tube current reduction on left ventricular (LV) regional wall motion assessment and ejection fraction (EF) by comparing low-radiation helical dual-source CT (DSCT) to 2-dimensional transthoracic echocardiography (2D-TTE).

METHODS: We studied 83 consecutive patients (15 with prior myocardial infarction) who underwent helically acquired DSCT coronary angiography with maximal ECG-based tube current modulation (low-radiation helical DSCT) and 2D-TTE within a 6-month period (median, 1 day), without any change in clinical status between the studies. In all patients, full tube current was applied only at 70% of the R-R interval, with minimal tube current (4% of maximum) in all other parts of the cardiac cycle. Reduced tube voltage (100 kVp) was combined with the maximal dose modulation in 34 patients. DSCT datasets were evaluated by a blinded, experienced cardiologist. Regional wall motion was assessed with the standard 17-segment model, with each segment scored as normal, hypokinetic, akinetic, and dyskinetic.

RESULTS: Mean effective radiation dose for the low-radiation helical DSCT was 5.2 ± 1.7 mSv. Regional wall motion was evaluable in all segments on low-radiation helical DSCT. There was excellent agreement of wall motion scoring by low-radiation helical DSCT and 2D-TTE in 1382 of 1411 segments (98%; Cohen’s κ value 0.83; 95% confidence interval, 0.76-0.89; P < 0.0001). Mean LVEF was 67.6% ± 10.3% on low-radiation helical DSCT and 61.8% ± 10.3% on 2D-TTE (P < 0.0001).

CONCLUSION: Low-radiation dose helical coronary CT angiography with maximal ECG-based tube current modulation is comparable to 2D-TTE for regional wall motion and EF assessment.

PMID: 21367686

Mar201101

1

Effects of Aspirin Responsiveness and Platelet Reactivity on Early Vein Graft Thrombosis After Coronary Artery Bypass Graft Surgery

J Am Coll Cardiol. 2011; 57(9):1069-1077

Gluckman TJ, McLean RC, Schulman SP, Kickler TS, Shapiro EP, Conte JV, McNicholas KW, Segal JB, Rade JJ

OBJECTIVES: The purpose of this study was to determine if an incomplete response to or inadequate antiplatelet effect of aspirin, or both, contribute to saphenous vein graft (SVG) occlusion after coronary artery bypass graft (CABG) surgery.  Thrombosis is the predominant cause of early SVG occlusion. Aspirin, which inhibits cyclooxygenase-1 activity and thromboxane generation in platelets, reduces early SVG occlusion by one-half.

METHODS: Aspirin responsiveness and platelet reactivity were characterized 3 days and 6 months after coronary artery bypass graft surgery in 229 subjects receiving aspirin monotherapy by platelet aggregation to arachidonic acid, adenosine diphosphate, collagen and epinephrine, Platelet Function Analyzer-100 (Siemens Healthcare Diagnostics, Newark, Delaware) closure time (CT) using collagen/epinephrine agonist cartridge and collagen/adenosine diphosphate (CADP) agonist cartridge, VerifyNow Aspirin assay (Accumetrics, Inc., San Diego, California), and urine levels of 11-dehydro-thromboxane B(2) (UTXB(2)). SVG patency was determined 6 months after surgery by computed tomography coronary angiography.

RESULTS: Inhibited arachidonic acid-induced platelet aggregation, indicative of aspirin-mediated cyclooxygenase-1 suppression, occurred in 95% and >99% of subjects 3 days and 6 months after surgery, respectively. Despite this, 73% and 31% of subjects at these times had elevated UTXB(2). Among tested parameters, only UTXB(2) and CADP CT measured 6 months after surgery correlated with outcome. By multivariate analysis, CADP CT of ≤88 s (odds ratio: 2.85, p = 0.006), target vessel diameter of ≤1.5 mm (odds ratio: 2.38, p = 0.01), and UTXB(2) of ≥450 pg/mg creatinine (odds ratio: 2.59, p = 0.015) correlated with SVG occlusion. CADP CT and UTXB(2) in combination further identified subjects at particularly high and low risk for SVG occlusion.

CONCLUSIONS: Aspirin-insensitive thromboxane generation measured by UTXB(2) and shear-dependent platelet hyper-reactivity measured by Platelet Function Analyzer-100 CADP CT are novel independent risk factors for early SVG thrombosis after coronary artery bypass graft surgery.

PMID: 21349398

Feb201115

2

Noninvasive Evaluation of Coronary Reperfusion by CT Angiography in Patients With STEMI

J Am Coll Cardiol Img. 2011; 4(2):141-149

Yamashita M, Lee S, Hamasaki S, Nishimoto T, Kajiya T, Toyonaga K, Arima R, Toda H, Ohba I, Otsuji Y, Tei C

OBJECTIVES: The aim of this study was to determine whether 64-slice multidetector computed tomography (MDCT) can differentiate coronary reperfusion with Thrombolysis In Myocardial Infarction (TIMI) flow grade 3 from TIMI flow grade ≤2 after ST-segment elevation myocardial infarction (STEMI).  Multidetector computed tomography has become a popular modality for noninvasive coronary artery imaging. Recently, 64-slice MDCT has been applied to evaluate coronary arteries in acute coronary artery disease.

METHODS: The presence or absence of distal reperfusion in infarct-related arteries (IRA) was visualized with 64-slice MDCT during the acute phase in 87 non–high-risk patients after STEMI. To differentiate TIMI flow grade 3 from TIMI flow grade 2, we calculated the computed tomography (CT) number ratio by dividing the CT number of the contrast-enhanced coronary lumen at the most distal IRA by that at the proximal site to the culprit lesion in patients with reperfusion on MDCT. The MDCT findings were compared with TIMI flow grade with invasive coronary angiography (ICA) performed 20 ± 5 min later.

RESULTS: According to ICA, 58 patients had TIMI flow grade 0 or 1, 17 had TIMI flow grade 2, and 12 had TIMI flow grade 3, whereas distal reperfusion was evident on MDCT in 28 of the 29 patients with TIMI flow grade ≥2 and absent in 55 of the 58 with TIMI flow grade ≤1. The CT number ratio was significantly higher in TIMI flow grade 3 than in TIMI flow grade ≤2 (0.64 ± 0.11 vs. 0.37 ± 0.12; p < 0.0001). The sensitivity, specificity, and accuracy of a diagnosis of TIMI flow grade 3 on the basis of a CT number ratio of ≥0.54 that was an optimal cutoff value determined by receiver-operator characteristic curve analysis were 92%, 97%, and 97%, respectively.

CONCLUSONS: Visualization of the IRA by 64-slice MDCT enables noninvasive differentiation of angiographic TIMI flow grade 3 from TIMI flow grade ≤2 coronary reperfusion during the acute phase in patients with STEMI.

PMID:

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

« Older Entries   Recent Entries »