CT in planning transcatheter aortic valve implantation procedures and risk assessment.

For surgical aortic valve replacement, the Society of Thoracic Surgeons score (STSS) is the reference standard for the prediction of operative risk. In transcatheter aortic valve implantation (TAVI) though, where the procedure itself is minimally invasive, the traditional risk assessment is supplemented by CTA. Through a consistent approach to the acquisition of high-quality images and the standardised reporting of annular measurements and adverse root and vascular features, patients at risk of complications can be identified. In turn, this may allow for a personalised procedural approach and treatment strategies devised to potentially reduce or mitigate this risk. This article provides a systematic and standardised approach to pre-procedural work-up with computed tomography angiography (CTA) and explores the current state of evidence and future areas of development in this rapidly developing field.

Impact of scan quality on the diagnostic performance of CCTA, SPECT, and PET for diagnosing myocardial ischemia defined by fractional flow reserve.

BACKGROUND: Scan quality can have a significant effect on the diagnostic performance of non-invasive imaging techniques. However, the extent of its influence has scarcely been investigated in a head-to-head manner. METHODS: Two-hundred and eight patients underwent CCTA, SPECT, and PET prior to invasive fractional flow reserve measurements. Scan quality was classified as either good, moderate, or poor. RESULTS: Distribution of good, moderate, and poor quality scans was; CCTA; 66%, 22%, 13%; SPECT; 52%, 38%, 9%; PET; 86%, 13%, 1%. Good quality CCTA scans possessed a higher specificity (75% vs. 31%, p = 0.001), positive predictive value (PPV, 71% vs. 51%, p = 0.050), and accuracy (80% vs. 60%, p = 0.009) compared to moderate quality scans, while sensitivity (94%) and negative predictive value (NPV, 88%) were similar to moderate and poor quality scans. Sensitivity (76%), NPV (84%), and accuracy (85%) of good quality SPECT scans was superior to those of moderate (41% p = 0.001, 56% p = 0.010, 70% p = 0.010) and poor quality (30% p = 0.003, 65% p = 0.069, 63% p = 0.038). Specificity (92%) and PPV (87%) of good quality SPECT scans did not differ from scans of diminished quality. Good quality PET scans exhibited high sensitivity (84%), specificity (86%), NPV (88%), PPV (81%) and accuracy (85%), which was comparable to scans of lesser quality. Good quality CCTA, SPECT, and PET scans demonstrated a similar diagnostic accuracy (p = 0.247). CONCLUSION: Diagnostic performance of CCTA, and SPECT is hampered by scan quality, while the diagnostic value of PET is not affected. Good quality CCTA, SPECT, and PET scans possess a high diagnostic accuracy.

Data on the impact of scan quality on the diagnostic performance of CCTA, SPECT, and PET for diagnosing myocardial ischemia defined by fractional flow reserve on a per vessel level.

Scan quality directly impacts the diagnostic performance of non-invasive imaging modalities as reported in a substudy of the PACIFC-trial: "Impact of Scan Quality on the Diagnostic Performance of CCTA, SPECT, and PET for Diagnosing Myocardial Ischemia Defined by Fractional Flow Reserve" [1]. This Data-in-Brief paper supplements the hereinabove mentioned article by presenting the diagnostic performance of CCTA, SPECT, and PET on a per vessel level for the detection of hemodynamic significant coronary artery disease (CAD) when stratified according to scan quality and vascular territory.

The association of coronary lumen volume to left ventricle mass ratio with myocardial blood flow and fractional flow reserve.

BACKGROUND: A diminished coronary lumen volume to left ventricle mass ratio (V/M) derived from coronary computed tomography angiography (CCTA) has been proposed as factor contributing to impaired myocardial blood flow (MBF) even in the absence of obstructive disease on invasive coronary angiography (ICA). METHODS: Patients underwent CCTA, and positron emission tomography (PET) prior to ICA. Matched global V/M, global, and vessel specific hyperaemic MBF (hMBF), coronary flow reserve (CFR), and, FFR were available for 431 vessels in 152 patients. The median V/M (20.71 mm3/g) was used to divide the population into patients with either a low V/M or a high V/M. RESULTS: Overall, a higher percentage of vessels with an abnormal hMBF and FFR (34% vs. 19%, p = 0.009 and 20% vs. 9%, p = 0.004), as well as a lower FFR (0.93 [interquartile range: 0.85-0.97] vs. 0.95 [0.89-0.98], p = 0.016) values were observed in the low V/M group. V/M was weakly associated with vessel specific hMBF (R = 0.148, p = 0.027), and FFR (R = 0.156, p < 0.001). Among vessels with non-obstructive CAD on ICA (361 vessels), no association between V/M and vessel specific hMBF nor CFR was noted. However, in the absence of obstructive CAD, V/M was associated with (R = 0.081, p = 0.027), and independently predictive for FFR (p = 0.047). CONCLUSION: Overall, an abnormal vessel specific hMBF and FFR were more prevalent in patients with a low V/M compared to those with a high V/M. Furthermore, V/M was weakly associated with vessel specific hMBF and FFR. In the absence of obstructive CAD on ICA, V/M was weakly associated with notwithstanding independently predictive for FFR.

Automated SPECT analysis compared with expert visual scoring for the detection of FFR-defined coronary artery disease.

PURPOSE: Traditionally, interpretation of myocardial perfusion imaging (MPI) is based on visual assessment. Computer-based automated analysis might be a simple alternative obviating the need for extensive reading experience. Therefore, the aim of the present study was to compare the diagnostic performance of automated analysis with that of expert visual reading for the detection of obstructive coronary artery disease (CAD). METHODS: 206 Patients (64% men, age 58.2 ± 8.7 years) with suspected CAD were included prospectively. All patients underwent 99mTc-tetrofosmin single-photon emission computed tomography (SPECT) and invasive coronary angiography with fractional flow reserve (FFR) measurements. Non-corrected (NC) and attenuation-corrected (AC) SPECT images were analyzed both visually as well as automatically by commercially available SPECT software. Automated analysis comprised a segmental summed stress score (SSS), summed difference score (SDS), stress total perfusion deficit (S-TPD), and ischemic total perfusion deficit (I-TPD), representing the extent and severity of hypoperfused myocardium. Subsequently, software was optimized with an institutional normal database and thresholds. Diagnostic performances of automated and visual analysis were compared taking FFR as a reference. RESULTS: Sensitivity did not differ significantly between visual reading and most automated scoring parameters, except for SDS, which was significantly higher than visual assessment (p < 0.001). Specificity, however, was significantly higher for visual reading than for any of the automated scores (p < 0.001 for all). Diagnostic accuracy was significantly higher for visual scoring (77.2%) than for all NC images scores (p < 0.05), but not compared with SSS AC and S-TPD AC (69.8% and 71.2%, p = 0.063 and p = 0.134). After optimization of the automated software, diagnostic accuracies were similar for visual (73.8%) and automated analysis. Among the automated parameters, S-TPD AC showed the highest accuracy (73.5%). CONCLUSION: Automated analysis of myocardial perfusion SPECT can be as accurate as visual interpretation by an expert reader in detecting significant CAD defined by FFR.

Training and Service Provision in Cardiovascular CT: International Challenges and Solutions.

PURPOSE OF REVIEW: This manuscript identifies international challenges in cardiovascular CT that may prevent it from becoming a mainstream cardiovascular investigation. It offers potential solutions and a vision to overcome these barriers. RECENT FINDINGS: The acceptance of cardiovascular CT as a mainstream investigation now mandates a root and branch review of how we deliver a technology that is no longer emerging but recommended for mainstream clinical practice. The main challenges include investment in equipment and personnel and a substantial uplift in educational and training opportunities available. This requires revision of existing structures for training and accreditation and a broadening of these opportunities to include radiographers/technologists. The evidence for cardiovascular CT is overwhelming; the same energy and investment witnessed in driving the evidence base for this technology is now required in education and training. Failure to do so risks undermining the academic investment made over the last decade.

Longitudinal sequential biventricular assessment in adults with transposition of the great arteries and relationship with adverse outcomes.

BACKGROUND: In a cohort of congenitally corrected transposition of the great arteries (cc-TGA) and transposition of the great arteries after atrial switch procedure (d-TGA) the study objectives were: 1) to assess the change of quantitative systemic right ventricle (sRV) parameters over time and; 2) to examine the relationship of quantitative sRV parameters with adverse clinical outcomes. METHODS AND RESULTS: Single-center cohort study that included 49 (39%) cc-TGA and 76 (61%) d-TGA patients >18years who had at least one MUGA sRV assessment, 18/39 had more than one respectively. The primary clinical endpoint was all-cause mortality, heart transplantation and/or heart failure hospitalization. At a median clinical follow-up of 7years following the first MUGA, the primary endpoint occurred more often in cc-TGA versus d-TGA patients (18 (36.7%) vs. 9 (11.8%), p=0.03). Median time between the MUGA assessments was 5.8 (cc-TGA) and 4.9years (d-TGA). At last MUGA follow-up: 6 (33%) cc-TGA/14 (36%) d-TGA patients showed a significant decline in sRVEF (>5%); 6 (33%) cc-TGA/17 (44%) d-TGA patients had a significant increase in sRVEDVi; and 7 (39%) cc-TGA/19 (49%) PA-TGA patients had a significant increase in sRVESVi. Baseline sRV parameters were not associated with the primary end point or sRV changes over time. CONCLUSIONS: An important proportion of both patient cohorts demonstrated a significant change in sRV parameters over time and these are likely related to multiple factors that vary between individuals given population heterogeneity. The TGA patients have distinct clinical trajectories with increased adverse heart failure outcomes in the cc-TGA population and sRV parameters were not related to adverse heart failure events in either group.

Independent association of subclinical coronary artery disease and emphysema in HIV-infected patients.

OBJECTIVES: Chronic obstructive pulmonary disease (COPD) and coronary artery disease are inflammatory states with a significant clinical impact. The relationship between them has not been investigated in patients with HIV infection. We assessed the presence of subclinical emphysema and coronary artery disease using chest computed tomography (CT) imaging in a cohort of HIV-infected patients receiving antiretroviral therapy. METHODS: Gated chest CT scans were performed in 1446 consecutive patients to assess the presence and severity of coronary artery calcium (CAC) (classified as a score of 0, 1-100 or > 100) and emphysema (classified using a visual semiquantitative scale: 0, absent; 1-4, mild to moderate; > 4, severe). Univariable and multivariable logistic regression analyses were performed to identify factors independently associated with CAC and emphysema. RESULTS: The emphysema score was significantly higher in patients with CAC scores of 1-100 and > 100 compared with those with a CAC score of 0. After adjustments for age, sex, smoking status, pack-years of smoking, visceral adiposity and duration of HIV infection, the presence of any emphysema was significantly associated with a CAC score > 0 [odds ratio (OR) 1.43; 95% confidence interval (CI) 1.08-1.88; P = 0.012]. The association persisted after adjustment for the Framingham risk score (OR 1.52; 95% CI 1.16-1.99; P = 0.002). There was a dose-dependent effect in the association between emphysema score and CAC score. CONCLUSIONS: In this cross-sectional study of HIV-infected patients, there was an independent association between emphysema and CAC, after adjustment for traditional cardiovascular risk factors, suggesting a common pathogenesis of these chronic inflammatory conditions in a chronic inflammatory disease such as HIV infection.

Incremental diagnostic value of epicardial adipose tissue for the detection of functionally relevant coronary artery disease.

BACKGROUND AND AIM: To determine the incremental diagnostic value of epicardial adipose tissue (EAT) volume in addition to the coronary artery calcium (CAC) score for detecting hemodynamic significant coronary artery disease (CAD). METHODS AND RESULTS: 122 patients (mean age 61 ± 10 years, 61% male) without a previous cardiac history underwent a non-contrast CT scan for calcium scoring and EAT volume measurements. Subsequently all patients underwent invasive coronary angiography (ICA) in conjunction with fractional flow reserve (FFR) measurements. A stenosis >90% and/or a FFR ≤0.80 were considered significant. Mean EAT volume and CACscore were 128 ± 51 cm(3) and 418 ± 704, respectively. The correlation between EAT volume and the CACscore was poor (r = 0.11, p = 0.24). Male gender (odds ratio [OR] 2.86, p = 0.01), CACscore ([cut-off value 100] OR 3.31, p = 0.003, and EAT volume ([cut-off value 92 cm(3)] OR 4.28, p = 0.01) were associated with flow-limiting disease. The multivariate model revealed that only male gender (OR 2.50, p = 0.045), CAC score (OR 3.60, p = 0.005), and EAT volume (OR 4.95, p = 0.02) were independent predictors of myocardial ischemia. Using the cut-off values of 100 (CAC score) and 92 cm(3) (EAT volume), sensitivity, specificity, negative predictive value, positive predictive value, and accuracy for detecting functionally relevant CAD as indicated by FFR were 71, 57, 77, 50 and 63% and 91, 29, 85, 44 and 52% for the CACscore and EAT volume, respectively. Adding EAT volume to the CAC score and cardiovascular risk factors did not enhance diagnostic performance for the detection of significant CAD (p = 0.57). CONCLUSION: EAT volume measurements have no diagnostic value beyond calcium scoring and cardiovascular risk factors in the detection of hemodynamic significant CAD.

Characteristics of COPD in never-smokers and ever-smokers in the general population: results from the CanCOLD study.

BACKGROUND: There is limited data on the risk factors and phenotypical characteristics associated with spirometrically confirmed COPD in never-smokers in the general population. AIMS: To compare the characteristics associated with COPD by gender and by severity of airway obstruction in never-smokers and in ever-smokers. METHOD: We analysed the data from 5176 adults aged 40 years and older who participated in the initial cross-sectional phase of the population-based, prospective, multisite Canadian Cohort of Obstructive Lung Disease study. Never-smokers were defined as those with a lifetime exposure of <1/20 pack year. Logistic regressions were constructed to evaluate associations for 'mild' and 'moderate-severe' COPD defined by FEV1/FVC <5th centile (lower limits of normal). Analyses were performed using SAS V.9.1 (SAS Institute, Cary, North Carolina, USA). RESULTS: The prevalence of COPD (FEV1/FVC

Fractional flow reserve derived from coronary CT angiography in stable coronary disease: a new standard in non-invasive testing?

Fractional flow reserve (FFR) measured during invasive coronary angiography is the gold standard for lesion-specific decisions on coronary revascularization in patients with stable coronary artery disease (CAD). Current guidelines recommend non-invasive functional or anatomic testing as a gatekeeper to the catheterization laboratory. However, the "holy grail" in non-invasive testing of CAD is to establish a single test that quantifies both coronary lesion severity and the associated ischemia. Most evidence to date of such a test is based on the addition of computational analysis of FFR to the anatomic information obtained from standard-acquired coronary CTA data sets at rest (FFRCT). This review summarizes the clinical evidence for the use of FFRCT in stable CAD in context to the diagnostic performance of other non-invasive testing modalities. Key Points • The process of selecting appropriate patients for invasive coronary angiography is inadequate • Invasive fractional flow reserve is the standard for assessing coronary lesion-specific ischemia • Fractional flow reserve may be derived from standard coronary CT angiography (FFR CT ) • FFR CT provides high diagnostic performance in stable coronary artery disease.

The association between physical activity and liver fat after five years of follow-up in a primary prevention multi-ethnic cohort.

OBJECTIVE: Excess liver fat (LF) is associated with dyslipidemia, insulin resistance and cardiovascular disease. Evidence suggests that there is an independent relationship between physical activity (PA) and LF although little is known of the role of PA intensity in reducing LF. The purpose was to evaluate whether meeting PA guidelines, the amount of PA and the intensity of PA at baseline were associated with LF after five-years. METHODS: Men and women (n=478) living in Vancouver, Canada of Aboriginal, Chinese, European or South Asian background completed baseline measurements in 2004-2005. Liver fat was assessed using CT scans at 5-year follow-up, and PA using a PA questionnaire at baseline as well as demographics and anthropometry. RESULTS: In separate unadjusted models, meeting moderate-vigorous PA (MVPA) guidelines (p=0.009), vigorous PA (p=0.002) and MVPA (p=0.017) but not moderate PA (p=0.068) was predictive of LF at five years (p=0.009). In multiple linear regression models, when adjusted for covariates, meeting MVPA guidelines and MVPA with LF at five years was no longer significant (p>0.05) while vigorous PA remained significant (p=0.021). CONCLUSION: Meeting PA guidelines through MVPA may not be adequate to prevent the accumulation of LF and PA guidelines may require revision. Vigorous PA should be encouraged to prevent LF accumulation.

Recent advances in thoracic x-ray computed tomography for pulmonary imaging.

The present article reviews recent advances in pulmonary computed tomography (CT) imaging, focusing on the application of dual-energy CT and the use of iterative reconstruction. Dual-energy CT has proven to be useful in the characterization of pulmonary blood pool in the setting of pulmonary embolism, characterization of diffuse lung parenchymal diseases, evaluation of thoracic malignancies and in imaging of lung ventilation using inhaled xenon. The benefits of iterative reconstruction have been largely derived from reduction of image noise compared with filtered backprojection reconstructions which, in turn, enables the use of lower radiation dose CT acquisition protocols without sacrificing image quality. Potential clinical applications of iterative reconstruction include imaging for pulmonary nodules and high-resolution pulmonary CT.

Multidetector computed tomography in transcatheter aortic valve implantation. Where we stand.

Degenerative calcific aortic stenosis represents the most common valve abnormality with increasing incidence in the elderly. Studies have shown that aortic stenosis is a fatal disease with a high cardiovascular death rate if untreated. However, many patients are encumbered with multiple comorbidities making them high-risk candidates for surgical aortic valve replacement, which is the hitorical treatment of choice. Transcatheter aortic valve implantation (TAVI) has seen rapid advancements over the last number of years with over 50000 TAVI procedures being performed in 40 countries with excellent prognosis proving TAVI to be a feasible alternative therapy to traditional surgical aortic valve replacement to treat high-risk patients. In addition to clinical suitability, imaging plays an essential role for optimal patient selection and to help select the appropriate prosthesis and to help reduce the likelihood of complications and adverse events. Fundamental to the procedure success, is the non-invasive assessment of the aortic annulus, the evaluation of the aortic root and the determination of the access to the aortic annulus. Among different imaging modalities that have been employed, multidetector computed tomography (MDCT) is increasingly used because of its capability of 3-dimentional (3D) determination of the non-circular nature of the aortic annulus as well as the complex aortic root anatomy. Additionally, MDCT provides a deep understanding of the structural integrity of the transcatheter aortic valve and enables the evaluation of the prosthesis location after TAVI and identification of post procedure complications. In this article, we discuss the current role of MDCT in pre-TAVI evaluation but also in the guidance of the procedure and in post-procedure follow-up.

Transvaginal strangulated small intestinal hernia after abdominal sacrocolpopexy: case report and literature review.

PURPOSE: To report a case of transvaginal small intestinal hernia following abdominal sacrocolpopexy and review this clinical presentation in the current literature. METHODS: A review of our case and a literature review of vaginal evisceration were carried out. RESULTS: The patient underwent sacrocolpopexy and a Burch procedure. Six months later, a recurrent enterocele through a 1 cm defect in the vaginal vault was diagnosed. Several weeks later she presented with an incarcerated and strangulated loop of small intestine extending beyond the introitus. This required an urgent exploratory laparotomy, ileocecal resection, and vaginal vault closure. Postoperatively, she experienced gradual prolapse recurrence and is currently successfully managed with a pessary. Risk factors that include vaginal atrophy, chronic constipation, and previous pelvic surgery may have contributed to the evisceration, mesh erosion, and may have caused the breakdown in the vaginal vault mucosa ultimately responsible for the evisceration. In addition, placement of the sacrocolpopexy mesh without tension, and utilization of an interposition graft to reinforce the weakened vaginal vault tissue, are aspects of the surgical procedure that may influence outcomes. At the time of evisceration repair, the best approach to resuspend the vaginal vault, and prevent recurrent prolapse or evisceration, is currently unknown. CONCLUSION: Vaginal evisceration is a potential complication of abdominal sacrocolpopexy. Early recognition and treatment of this complication is critical, and prolapse recurrence may occur even after surgical repair.

Transcatheter aortic valve implantation: durability of clinical and hemodynamic outcomes beyond 3 years in a large patient cohort.

BACKGROUND: Although short- and medium-term outcomes after transcatheter aortic valve implantation are encouraging, long-term data on valve function and clinical outcomes are limited. METHODS AND RESULTS: Consecutive high-risk patients who had been declined as surgical candidates because of comorbidities but who underwent successful transcatheter aortic valve implantation with a balloon-expandable valve between January 2005 and December 2006 and survived past 30 days were assessed. Clinical, echocardiographic, and computed tomographic follow-up examinations were performed. Seventy patients who underwent successful procedures and survived longer than 30 days were evaluated at a minimum follow-up of 3 years. At a median follow-up of 3.7 years (interquartile range 3.4 to 4.3 years), survival was 57%. Survival at 1, 2, and 3 years was 81%, 74%, and 61%, respectively. Freedom from reoperation was 98.5% (1 patient with endocarditis). During this early procedural experience, 11 patients died within 30 days, and 8 procedures were unsuccessful. When these patients were included, overall survival was 51%. Transaortic pressure gradients increased from 10.0 mm Hg (interquartile range 8.0 to 12.0 mm Hg) immediately after the procedure to 12.1 mm Hg (interquartile range 8.6 to 16.0 mm Hg) after 3 years (P=0.03). Bioprosthetic valve area decreased from a mean of 1.7±0.4 cm(2) after the procedure to 1.4±0.3 cm(2) after 3 years (P<0.01). Aortic incompetence after implantation was trivial or mild in 84% of cases and remained unchanged or improved over time. There were no cases of structural valvular deterioration, stent fracture, deformation, or valve migration. CONCLUSIONS: Transcatheter aortic valve implantation demonstrates good medium- to long-term durability and preserved hemodynamic function, with no evidence of structural failure. The procedure appears to offer an adequate and lasting resolution of aortic stenosis in selected patients.

Submillisievert coronary computed tomography angiography using adaptive statistical iterative reconstruction - a new reality.

Coronary computed tomography angiography (CCTA) is becoming an increasingly robust tool in the assessment and exclusion of coronary artery disease. Multiple recent studies have raised concerns regarding the radiation dose exposure of CCTA. A novel approach to dose reduction in CCTA using adaptive statistical iterative reconstruction, resulting in a submillisievert CCTA examination, is described. To the authors' knowledge, the present report describes the first submillisievert study performed in Canada. The ability to perform a diagnostic CCTA with such a low dose challenges the role of coronary calcium scoring and will likely have implications for the future use of this test.

Neuroleptic malignant syndrome in the elderly.

Four cases of neuroleptic malignant syndrome (NMS) were identified in a general hospital over a 5-year period. Two cases presented to the psychiatric consultation liaison service, and two were found by a computerized review of discharge diagnoses. Cases were examined for age, sex, administered neuroleptic potency and dose, premorbid history, prodromal symptoms, methods of treatment, and clinical outcome. The mean age of cases was found to be 14 years greater than the age of the non-NMS patient population. All NMS cases had premorbid neuropsychiatric disorders and recognizable prodromal symptoms. The mean neuroleptic dose was significantly lower than in previously reported cases. A systems model integrating premorbid factors, intercurrent illness, and drug effects in pathogenesis is presented.