Circ Cardiovasc Imaging.. 2010; 3(4):351-9

Russo V, Zavalloni A, Bacchi Reggiani ML, Buttazzi K, Gostoli V, Bartolini S, Fattori R.

BACKGROUND: Multidetector CT coronary angiography (MDCTCA) is capable of detecting coronary artery disease (CAD) with a high diagnostic accuracy. In particular, this technique is credited with having a negative predictive value close to 100%. However, data about the prognostic value of MDCTCA are currently lacking. We sought to determine the prognostic value of MDCTCA in patients with suspected but undocumented CAD and, in particular, the incremental prognostic value as compared with clinical risk and calcium scoring.

METHODS AND RESULTS: A total of 441 patients (age, 59.7+/-11.6 years) with suspected CAD underwent MDCTCA to evaluate the presence and severity of the disease. Patients were followed up as to the occurrence of hard cardiac events (cardiac death, nonfatal myocardial infarction, and unstable angina requiring hospitalization). Coronary lesions were detected in 297 (67.3%) patients. During a mean follow-up of 31.9+/-14.8 months, 44 hard cardiac events occurred in 40 patients. CT calcium scoring showed a statistically significant incremental prognostic value as compared to a baseline clinical risk model (P=0.018), whereas MDCTCA provided an additional incremental prognostic value as compared with a baseline clinical risk model plus calcium scoring if considering both nonobstructive versus obstructive CAD (P=0.016) or, better, plaque composition (calcified versus noncalcified and/or mixed plaques, P=0.0001). During follow-up, an excellent prognosis was noted in patients with normal coronary arteries, with an annualized incidence rate of 0.88% if compared with those with mild CAD (3.89%) and with patients with significant coronary disease (8.09%). The presence of noncalcified or mixed plaques, regardless of lesion severity, was found to be the strongest predictor of events (P<0.0001) as a potential marker of plaque vulnerability.

CONCLUSIONS: MDCTCA provides independent and incremental prognostic information as compared to baseline clinical risk factors and calcium scoring in patients with suspected CAD.

PMID: 20460497

Radiology. 2010; 256(2):245-253

Astor BC, Sharrett AR, Coresh J, Chambless LE, Wasserman BA

OBJECTIVES: To determine the extent of thickening of the carotid arterial walls that may be accommodated by outward remodeling.

METHODS: Institutional review board approval was obtained at each participating site, and informed consent was obtained from each participant. All study sites conducted this study in compliance with HIPAA requirements. A total of 2066 participants (age range, 60-85 years) from the Atherosclerosis Risk in Communities (ARIC) study were enrolled in the ARIC Carotid MRI Study. Maximum wall thickness and luminal area were measured with gadolinium-enhanced magnetic resonance (MR) imaging in both common carotid arteries (CCAs) and in one internal carotid artery (ICA) 2 mm above the flow divider. Complete data were available for 1064 ICAs and 3348 CCAs. The association of maximum wall thickness with lumen area was evaluated with linear regression, and adjustments were made for participant age, sex, race, height, and height squared.

RESULTS: In the ICA, lumen area was relatively constant across patients with a wall thickness of 1.38 mm or less. In patients with a wall thickness of more than 1.38 mm, however, lumen area decreased linearly as wall thickness increased. Wall area represented a median of 61.9% of the area circumscribed by the vessel at a maximum wall thickness of 1.50 mm +/- 0.05 (standard deviation) and 75.4% at a maximum wall thickness of 4.0 mm +/- 0.10. In the CCA, lumen area was preserved across wall thicknesses less than 2.06 mm, representing 99% of vessels.

CONCLUSIONS: Atherosclerotic thickening in the ICA appears to be accommodated for vessels with a maximum wall thickness of less than 1.5 mm. Beyond this threshold, greater thickness is associated with a smaller lumen. The CCA appears to accommodate a wall thickness of less than 2.0 mm. These estimates indicate that the carotid arteries are able to compensate for a greater degree of thickening than are the coronary arteries.

PMID: 20651061

J Am Coll Cardiol. 2010; 56(6):455-462

Jan D. Schmitto, Suyog A. Mokashi, Lawrence H. Cohn

Minimally-invasive approaches have become increasingly important in cardiac valve surgery. Smaller incisions have become commonplace in many major centers. We reviewed the existing literature and present the current state-of-the-art of minimally-invasive valve operations in this paper.

PMID:

Heart. 2010; 96(16):1303-1310

Austin BA, Popovic ZB, Kwon DH, Thamilarasan M, Boonyasirinant T, Flamm SD, Lever HM, Desai MY

PMID:

Eur Heart J . 2010; 34(14):563-576

Pasquale Perrone-Filardi, Stephan Achenbach, Stefan Möhlenkamp, Zeljko Reiner, Gianmario Sambuceti, Joanne D. Schuijf, Ernst Van der Wall, Philip A. Kaufmann, Juhani Knuuti, Stephen Schroeder, Michael J. Zellweger

OBJECTIVES: Cardiovascular events remain one of the most frequent causes of mortality and morbidity worldwide. The majority of cardiac events occur in individuals without known coronary artery disease (CAD) and in low- to intermediate-risk subjects. Thus, the development of improved preventive strategies may substantially benefit from the identification, among apparently intermediate-risk subjects, of those who have a high probability for developing future cardiac events. Cardiac computed tomography and myocardial perfusion scintigraphy (MPS) by single photon emission computed tomography may play a role in this setting. In fact, absence of coronary calcium in cardiac computed tomography and inducible ischaemia in MPS are associated with a very low rate of major cardiac events in the next 3–5 years.

METHODS: Based on current evidence, the evaluation of coronary calcium in primary prevention subjects should be considered in patients classified as intermediate-risk based on traditional risk factors, since high calcium scores identify subjects at high-risk who may benefit from aggressive secondary prevention strategies. In addition, calcium scoring should be considered for asymptomatic type 2 diabetic patients without known CAD to select those in whom further functional testing by MPS or other stress imaging techniques may be considered to identify patients with significant inducible ischaemia.

RESULTS: From available data, the use of MPS as first line testing modality for risk stratification is not recommended in any category of primary prevention subjects with the possible exception of first-degree relatives of patients with premature CAD in whom MPS may be considered.

CONCLUCIONS: However, the Working Group recognizes that neither the use of computed tomography for calcium imaging nor of MPS have been proven to significantly improve clinical outcomes of primary prevention subjects in prospective controlled studies. This information would be crucial to adequately define the role of imaging approaches in cardiovascular preventive strategies.

PMID: 20630895

International Journal of Cardiovascular Imaging. 2010; 49(6):754-756

Alina G. van der Giessen, Frank J. H. Gijsen, Jolanda J. Wentzel, Pushpa M. Jairam, Theo van Walsum, Lisan A. E. Neefjes, Nico R. Mollet, Wiro J. Niessen, Frans N. van de Vosse, Pim J. de Feyter, Antonius F. W. van der Steen

OBJECTIVES: Recently, small calcifications have been associated with unstable plaques. Plaque calcifications are both in intravascular ultrasound (IVUS) and multi-slice computed tomography (MSCT) easily recognized. However, smaller calcifications might be missed on MSCT due to its lower resolution.

METHODS: Because it is unknown to which extent calcifications can be detected with MSCT, we compared calcification detection on contrast enhanced MSCT with IVUS. The coronary arteries of patients with myocardial infarction or unstable angina were imaged by 64-slice MSCT angiography and IVUS. The IVUS and MSCT images were registered and the arteries were inspected on the presence of calcifications on both modalities independently. We measured the length and the maximum circumferential angle of each calcification on IVUS.

RESULTS: In 31 arteries, we found 99 calcifications on IVUS, of which only 47 were also detected on MSCT. The calcifications missed on MSCT (n = 52) were significantly smaller in angle (27° ± 16° vs. 59° ± 31°) and length (1.4 ± 0.8 vs. 3.7 ± 2.2 mm) than those detected on MSCT. Calcifications could only be detected reliably on MSCT if they were larger than 2.1 mm in length or 36° in angle.

CONCLUSIONS: Half of the calcifications seen on the IVUS images cannot be detected on contrast enhanced 64-slice MSCT angiography images because of their size. The limited resolution of MSCT is the main reason for missing small calcifications.

PMID: 20602171

J Am Coll Cardiol. 2010; 56(7):278-287

Azevedo CF, Nigri M, Higuchi ML, Pomerantzeff PM, Spina GS, Sampaio RO, Tarasoutchi F, Grinberg M, Rochitte CE.

OBJECTIVES: Does myocardial fibrosis (MF) in patients with severe aortic valve (AV) disease, assessed by histopathology or contrast-enhanced magnetic resonance imaging (ce-MRI), predict outcomes following surgical AV replacement?

METHODS: Fifty-four patients (mean age 46.8 years, 78% male) with symptomatic severe aortic regurgitation (n = 26) or aortic stenosis (n = 28) were prospectively evaluated. All patients underwent preoperative quantitative assessment of MF by ce-MRI and had myocardial tissue samples obtained during surgery for histopathologic evaluation. Patients were grouped based on degree of MF and were compared to assess for differences in left ventricular (LV) functional improvement and survival postoperatively.

RESULTS: ce-MRI assessment of MF correlated well with histopathology (r = 0.69, p < 0.0001), and the degree of MF was higher in the study group than in normal controls. LV functional changes were evaluated in 25 patients who underwent follow-up MRI; LV mass was decreased and LV ejection fraction (EF) improved (EF 54 ± 10% pre-op vs. 59 ± 14% post-op, p = 0.02). LVEF improvement was inversely related to the degree of pre-op MF. Overall, those who died had more MF, and this increased burden of MF was associated with lower postoperative survival. Finally, on multivariate analysis, the amount of MF, along with advanced age, independently predicted all-cause mortality.

CONCLUSIONS: In patients with severe AV disease, the amount of MF assessed by histopathology or ce-MRI is associated with LV function improvement and mortality. 

PMID: 20633819

J Am Coll Cardiol Img. 2010; 3(7):691 - 698

K. Inoue, S. Motoyama, M. Sarai, T. Sato, H. Harigaya, T. Hara, Y. Sanda, H. Anno, T. Kondo, N. D. Wong

OBJECTIVES: This study sought to assess, by serial computed tomography angiography (CTA), the effect of statin treatment on coronary plaque morphology. In addition to the assessment of luminal stenosis, CTA also allows characterization of plaque morphology. Large, positively remodeled plaques with large necrotic cores have been reported as indicators of plaque instability.

METHODS: CTA was performed in 32 patients (26 men, ages 64.3 ± 8.5 years). Of these, 24 received fluvastatin after the baseline study; 8 subjects who refused statin treatment were followed as the control subjects. Serial imaging was performed after a median interval of 12 months. All vessels were examined in every subject, and a 10-mm-long segment was identified for comparison before and after intervention. Total plaque volume, low attenuation plaque (LAP) volume, lumen volume, and remodeling index were calculated.

RESULTS: In the statin-treated patients, the total plaque volume (92.3 ± 37.7 vs. 76.4 ± 26.5 mm³, p < 0.01) and LAP volume (4.9 ± 7.8 vs. 1.3 ± 2.3 mm³, p = 0.01) were significantly reduced over time; however, there was no change in the lumen volume (63.9 ± 25.3 vs. 65.2 ± 26.2 mm³, p = 0.59). On the other hand, no change was observed in the CTA characteristics in the control subjects, including total plaque volume (94.4 ± 21.2 vs. 98.4 ± 28.6 mm³, p = 0.48), LAP volume (2.1 ± 3.0 vs. 2.3 ± 3.6 mm³, p = 0.91), and lumen volume (80.5 ± 20.7 vs. 75.0 ± 16.3 mm³, p = 0.26). The plaque volume change (–15.9 ± 22.2 vs. 4.0 ± 14.0 mm³, p = 0.01) and LAP volume change (–3.7 ± 7.0 vs. 0.2 ± 1.5 mm³, p < 0.01) were significantly greater in the statin than the control group. The lumen volume (1.3 ± 15.6 vs. –5.5 ± 13.1 mm³, p = 0.24) and remodeling index (–2.4 ± 6.8% vs. –0.3 ± 6.5%, p = 0.53) did not show the significant differences between the 2 groups. The decrease in the plaque volume was due to reduction in the LAP volume (R = 0.83, p < 0.01), and was not related to any changes in the lumen volume (R = 0.21, p = 0.24).

CONCLUSIIONS: This preliminary study suggests that serial CTA evaluation of coronary plaques allows for the assessment of interval change in the plaque morphology. Statin treatment results in decreases in the plaque and necrotic core volume. The features known to be associated with plaque instability.

PMID:

Eur Heart J . 2010; 34(14):254-265

Mohamed Marwan, Tobias Pflederer, Tiziano Schepis, Alexandra Lang, Gerd Muschiol, Dieter Ropers, Werner G. Daniel, Stephan Achenbach

OBJECTIVES: It has been previously reported that the sensitivity and specificity of multislice computed tomography (CT) for detecting significant coronary artery disease (CAD) is high. However, regular sinus rhythm has been considered a prerequisite for an adequate examination, even though atrial fibrillation (AF) is common among patients evaluated for the presence of coronary heart disease. In this study, we investigated the sensitivity and specificity of dual-source CT (DSCT) to detect and rule out significant coronary stenoses in patients with AF referred for invasive coronary angiography.

PMID:

J Am Coll Cardiol. 2010; 56(3):544-549

Chen J, Einstein A, Fazel R

OBJECTIVES: The purpose of this study was to describe radiation exposure from cardiac imaging procedures over time in a general population. Cardiac imaging procedures frequently expose patients to ionizing radiation, but their contribution to effective doses of radiation in the general population is unknown.

METHODS: We used administrative claims to identify cardiac imaging procedures performed from 2005 to 2007 in 952,420 nonelderly insured adults in 5 U.S. health care markets. We estimated 3-year cumulative effective doses of radiation in millisieverts from these procedures We then calculated population-based annual rates of radiation exposure to effective doses 3 mSv/year (background level ofradiation from natural sources), >3 to 20 mSv/year, or >20 mSv/year (upper annual limit for occupational exposure averaged over 5 years).

RESULTS: A total of 90,121 (9.5%) individuals underwent at least 1 cardiac imaging procedure using radiation. Among patients who underwent 1 cardiac imaging procedures, the mean cumulative effective dose over 3 years was 16.4 mSv (range 1.5 to 189.5 mSv). Myocardial perfusion imaging accounted for 74% of the cumulative effective dose. Overall, 47.8% of cardiac imaging procedures were performed in physician offices; this proportion was higher for myocardial perfusion imaging (74.8%) and cardiac computed tomography studies (76.5%). The annual population-based rate of receiving an effective dose of >3 to 20 mSv/year was 89.0 per 1,000; and 3.3 per 1,000 for cumulative doses >20 mSv/year. Annual effective doses increased with age and were generally higher among men.

CONCLUSIONS: Cardiac imaging procedures lead to substantial radiation exposure and effective doses for many patients in the U.S.

PMID: