Measurement of Aortic Valve Calcification Using Multislice Computed Tomography: Correlation With Haemodynamic Severity of Aortic Stenosis and Clinical Implication for Patients With Low Ejection Fraction

OBJECTIVES: Measurement of the degree of aortic valve calcification (AVC) using electron beam computed tomography (EBCT) is an accurate and complementary method to transthoracic echocardiography (TTE) for assessment of the severity of aortic stenosis (AS). Whether threshold values of AVC obtained with EBCT could be extrapolated to multislice computed tomography (MSCT) was unclear and AVC diagnostic value in patients with low ejection fraction (EF) has never been specifically evaluated.

METHODS: Patients with mild to severe AS underwent prospectively within 1 week MSCT and TTE. Severe AS was defined as an aortic valve area (AVA) of less than 1 cm(2). In 179 patients with EF greater than 40% (validation set), the relationship between AVC and AVA was evaluated. The best threshold of AVC for the diagnosis of severe AS was then evaluated in a second subset (testing set) of 49 patients with low EF (<40%). In this subgroup, AS severity was defined based on mean gradient, natural history or dobutamine stress echocardiography.

RESULTS: Correlation between AVC and AVA was good (r=-0.63, p<0.0001). A threshold of 1651 arbitrary units (AU) provided 82% sensitivity, 80% specificity, 88% negative-predictive value and 70% positive-predictive value. In the testing set (patients with low EF), this threshold correctly differentiated patients with severe AS from non-severe AS in all but three cases. These three patients had an AVC score close to the threshold (1206, 1436 and 1797 AU).

CONCLUSIONS: In this large series of patients with a wide range of AS, AVC was shown to be well correlated to AVA and may be a useful adjunct for the evaluation of AS severity especially in difficult cases such as patients with low EF.

PMID: 20720250

Septal Pouch in the Left Atrium and Risk of Ischemic Stroke

OBJECTIVES: We sought to assess the association between the presence of a septal pouch in the left atrium and ischemic stroke. It has been suggested that the presence of a left septal pouch (LSP) may favor the stasis of blood and possibly result in thromboembolic complications. However, the embolic potential of an LSP is not known.

METHODS: The association between an LSP and risk of stroke was assessed using a population-based case-control study design. The presence of an LSP was assessed by transesophageal echocardiography in 187 patients >50 years of age with a first-ever ischemic stroke (96 men, mean age 70.6 ± 9.0 years) and in 157 control subjects matched to patients by age, sex, and race/ethnicity. The association between an LSP and risk of stroke was assessed after adjustment for other stroke risk factors.

RESULTS: Patients with LSPs were younger than control subjects (67.5 ± 9.1 years vs. 69.6 ± 8.8 years; p = 0.046), with a lower prevalence of hypertension (68.0% vs. 80.3%; p = 0.01). There were no differences in the prevalence of LSPs between stroke patients and control subjects (28.9% vs. 29.3%, respectively; p = 0.93). The subgroup of 69 patients (36.9%) with cryptogenic stroke showed a similar prevalence of LSPs (31.9% vs. 29.3%; p = 0.70). Multivariable analysis showed that the presence of an LSP was not associated with ischemic stroke (odds ratio: 1.09; 95% confidence interval: 0.64 to 1.85) or cryptogenic stroke (odds ratio: 1.41; 95% confidence interval: 0.71 to 2.78).

CONCLUSIONS: This study does not demonstrate evidence of the association of the presence of an LSP with ischemic stroke or cryptogenic stroke. The stroke risk associated with LSPs requires further evaluation in the younger stroke populations. The cofactors that may turn an LSP from an innocent bystander to a causative mechanism for stroke remains to be elucidated.

PMID: 21163457

Prognostic Value of Cardiac Computed Tomography Angiography A Systematic Review and Meta-Analysis

OBJECTIVES: The purpose of this study was to systematically review and perform a meta-analysis of the ability of cardiac computed tomography angiography (CCTA) to predict future cardiovascular events and death. The diagnostic accuracy of CCTA is well reported. The prognostic value of CCTA has been described in several studies, but many were underpowered. Pooling outcomes increases the power to predict rare events.

METHODS: We searched multiple databases for longitudinal studies of CCTA with at least 3 months follow-up of symptomatic patients with suspected coronary artery disease (CAD) reporting major adverse cardiovascular events (MACE), consisting of death, myocardial infarction (MI), and revascularization. Annualized event rates were pooled using a bivariate mixed-effects binomial regression model to calculate summary likelihood ratios and receiver-operating characteristic curves.

RESULTS: Eighteen studies evaluated 9,592 patients with a median follow-up of 20 months. The pooled annualized event rate for obstructive (any vessel with >50% luminal stenosis) versus normal CCTA was 8.8% versus 0.17% per year for MACE (p < 0.05) and 3.2% versus 0.15% for death or MI (p < 0.05). The pooled negative likelihood ratio for MACE after normal CCTA findings was 0.008 (95% confidence interval [CI]: 0.0004 to 0.17, p < 0.001), the positive likelihood ratio was 1.70 (95% CI: 1.42 to 2.02, p <0.001), sensitivity was 0.99 (95% CI: 0.93 to 1.00, p < 0.001), and was specificity 0.41 (95% CI: 0.31 to 0.52, p < 0.001). Stratifying by no CAD, nonobstructive CAD (worst stenosis <50%), or obstructive CAD, there were incrementally increasing adverse events.

CONCLUSIONS: Adverse cardiovascular events among patients with normal findings on CCTA are rare. There are incrementally increasing future MACE with increasing CAD by CCTA.

PMID: 21145688

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

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

Myocardial Delayed Enhancement in Pulmonary Hypertension: Pulmonary Hemodynamics, Right Ventricular Function, and Remodeling

OBJECTIVES: The purpose of this study was to assess predictors of MRI-identified septal delayed enhancement mass at the right ventricular (RV) insertion sites in relation to RV remodeling, altered regional mechanics, and pulmonary hemodynamics in patients with suspected pulmonary hypertension (PH).

METHODS: Thirty-eight patients with suspected PH were evaluated with right heart catheterization and cardiac MRI. Ten age- and sex-matched healthy volunteers acted as controls for MRI comparison. Septal delayed enhancement mass was quantified at the RV insertions. Systolic septal eccentricity index, global RV function, and remodeling indexes were quantified with cine images. Peak systolic circumferential and longitudinal strain at the sites corresponding to delayed enhancement were measured with conventional tagging and fast strain-encoded MRI acquisition, respectively.

RESULTS: PH was diagnosed in 32 patients. Delayed enhancement was found in 31 of 32 patients with PH and in one of six patients in whom PH was suspected but proved absent (p = 0.001). No delayed enhancement was found in controls. Delayed enhancement mass correlated with pulmonary hemodynamics, reduced RV function, increased RV remodeling indexes, and reduced eccentricity index. Multiple linear regression analysis showed RV mass index was an independent predictor of total delayed enhancement mass (p = 0.017). Regional analysis showed delayed enhancement mass was associated with reduced longitudinal strain at the basal anterior septal insertion (r = 0.6, p < 0.01). Regression analysis showed that basal longitudinal strain remained an independent predictor of delayed enhancement mass at the basal anterior septal insertion (p = 0.02).

CONCLUSIONS: In PH, total delayed enhancement burden at the RV septal insertions is predicted by RV remodeling in response to increased afterload. Local fibrosis mass at the anterior septal insertion is associated with reduced regional longitudinal contractility at the base.

PMID: 21178051

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

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

Ionizing Radiation Exposure to Patients Admitted With Acute Myocardial Infarction in the United States

OBJECTIVES: Invasive and noninvasive cardiovascular imaging is beneficial in the care of patients admitted with acute myocardial infarction. Little is known about patients’ cumulative radiation exposure.

METHODS: All patients admitted with an acute myocardial infarction to any of 49 University HealthSystem Consortium member hospitals from 2006 to 2009 were reviewed for inpatient procedures involving ionizing radiation that included chest radiograph, computed tomogram scans, radionuclide imaging, diagnostic cardiac catheterization, and percutaneous coronary intervention. The average cumulative effective radiation dose per patient was estimated on the basis of published typical effective radiation doses for imaging procedures.

RESULTS: Patients (n=64 071) admitted for acute myocardial infarction had a median age of 64.9 years. A total of 276 651 procedures involving ionizing radiation were performed during the study period, a median of 4.3 procedures per patient per admission. The majority of patients had invasive catheterization (77%), followed by computed tomogram scans (52%), mostly body examinations. The median cumulative effective radiation dose delivered was 15.02 mSv per patient per acute myocardial infarction admission. Postprocedural bleeding was a significant predictor of radiation exposure (odds ratio, 2.01; 95% confidence interval, 1.85 to 2.18), together with postprocedural mechanical complications resulting from device implantation (odds ratio, 2.86; 95% confidence interval, 2.61 to 3.13). Patients with higher underlying clinical complexity (defined by severity of illness scores) had higher radiation exposure and higher mortality (P<0.0001). There was also significant geographic variation in radiation exposure; patients in New England received the lowest cumulative exposure (odds ratio, 0.78; 95% confidence interval, 0.74 to 0.81).

CONCLUSIONS: Acute myocardial infarction inpatients are exposed to an approximate median radiation dose of 15 mSv. This exposure is a result of multiple cardiovascular and noncardiovascular procedures. Efforts should be made to understand the risks and benefits of radiation exposure per episode of care for acute myocardial infarction.

PMID: 21060076

Prospectively Versus Retrospectively ECG-Gated 256-Slice Coronary CT Angiography: Image Quality and Radiation Dose Over Expanded Heart Rates

OBJECTIVES: To compare image quality and radiation dose estimates for coronary computed tomography angiography (CCTA) obtained with a prospectively gated transaxial (PGT) CT technique and a retrospectively gated helical (RGH) CT technique using a 256-slice multidetector CT (MDCT) scanner and establish an upper limit of heart rate to achieve reliable diagnostic image quality using PGT.

METHODS: 200 patients (135 males, 65 females) with suspected coronary artery disease (CAD) underwent CCTA on a 256-slice MDCT scanner. The PGT patients were enrolled prospectively from January to June, 2009. For each PGT patient, we found the paired ones in retrospective-gating patients database and randomly selected one patient in these match cases and built up the RGH group. Image quality for all coronary segments was assessed and compared between the two groups using a 4-point scale (1: non-diagnostic; 4: excellent). Effective radiation doses were also compared.

RESULTS: The average heart rate ± standard deviation (HR ± SD) between the two groups was not significantly different (PGT: 64.6 ± 12.9 bpm, range 45-97 bpm; RGH: 66.7 ± 10.9 bpm, range 48-97 bpm, P = 0.22). A receiver-operating characteristic (ROC) analysis determined a cutoff HR of 75 bpm up to which diagnostic image quality could be achieved using the PGT technique (P < 0.001). There were no significant differences in assessable coronary segments between the two groups for HR ≤ 75 bpm (PGT: 99.9% [961 of 962 segments]; RGH: 99.8% [1038 of 1040 segments]; P = 1.0). At HR > 75 bpm, the performance of the PGT technique was affected, resulting in a moderate reduction of percentage assessable coronary segments using this approach (PGT: 95.5% [323 of 338 segments]; RGH: 98.5% [261 of 265 segments]; P = 0.04). The mean estimated effective radiation dose for the PGT group was 3.0 ± 0.7 mSv, representing reduction of 73% compared to that of the RGH group (11.1 ± 1.6 mSv) (P < 0.001).

CONCLUSIONS: Prospectively-gated axial coronary computed tomography using a 256-slice multidetector CT scanner with a 270 ms tube rotation time enables a significant reduction in effective radiation dose while simultaneously providing image quality comparable to the retrospectively gated helical technique. Our experience demonstrates the applicability of this technique over a wider range of heart rates (up to 75 bpm) than previously reported.

PMID: 21153709

Incidence and Management of CoreValve Dislocation During Transcatheter Aortic Valve Implantation

OBJECTIVES: Transcatheter aortic valve implantation is a highly specialized technique offering a new therapeutic option to patients at high risk for conventional surgery. Complications associated with this catheter procedure differ from complications after surgical aortic valve replacement. This is to report incidence, management, and impact on morbidity and mortality of CoreValve dislocation during catheter valve implantation.

METHODS: Between June 2007 and September 2009, the self-expandable CoreValve prosthesis (Medtronic Inc, Minneapolis, Minn) was implanted in 212 patients through a transarterial (femoral or subclavian) access. Patients with severe aortic stenosis who were at high risk for conventional surgery were included.

RESULTS: We observed dislocation of the prosthesis during CoreValve implantation in 21 patients. In 16 cases, the CoreValve could be implanted in the correct annular position after retrieving it and reloading the catheter. In 4 patients, the completely deployed prosthesis had to be placed in the ascending or abdominal aorta before implanting a second one. One patient underwent open surgery. Overall 30-day mortality was 11.0%, 21.5% in the dislocation group and 9.9% in patients without dislocation (P=0.024). Coronary ischemia, stroke, and renal failure occurred more frequently in patients with dislocation, whereas pacemaker dependency did not differ significantly between the groups.

CONCLUSIONS: CoreValve dislocation during transcatheter aortic valve implantation occurred in 10% of the cases and significantly increases perioperative risk for severe complications or death. It requires individual specific management and can be managed either interventionally or, rarely, results in open surgery.

PMID: 21063000

Left Main Trunk Coronary Artery Dissection as a Consequence of Inaccurate Coronary Computed Tomographic Angiography

PMID:

Assessment of Myocardial Ischaemia and Viability: Role of Positron Emission Tomography

In developed countries, coronary artery disease (CAD) continues to be a major cause of death and disability. Over the past two decades, positron emission tomography (PET) imaging has become more widely accessible for the management of ischemic heart disease. Positron emission tomography has also emerged as an important alternative perfusion imaging modality in the context of recent shortages of molybdenum-99/technetium-99m ((99m)Tc). The clinical application of PET in ischaemic heart disease falls into two main categories: first, it is a well-established modality for evaluation of myocardial blood flow (MBF); second, it enables assessment of myocardial metabolism and viability in patients with ischaemic left ventricular dysfunction. The combined study of MBF and metabolism by PET has led to a better understanding of the pathophysiology of ischaemic heart disease.

While there are potential future applications of PET for plaque and molecular imaging, as well as some clinical use in inflammatory conditions, this article provides an overview of the physical and biological principles behind PET imaging and its main clinical applications in cardiology, namely the assessment of MBF and metabolism.

PMID: 20965888

Shortened Modified Look-Locker Inversion Recovery (ShMOLLI) for Clinical Myocardial T1-Mapping at 1.5 and 3 T Within A 9 Heartbeat Breathhold

OBJECTIVES: T1 mapping allows direct in-vivo quantitation of microscopic changes in the myocardium, providing new diagnostic insights into cardiac disease. Existing methods require long breath holds that are demanding for many cardiac patients. In this work we propose and validate a novel, clinically applicable, pulse sequence for myocardial T1-mapping that is compatible with typical limits for end-expiration breath-holding in patients.

METHODS: The Shortened MOdified Look-Locker Inversion recovery (ShMOLLI) method uses sequential inversion recovery measurements within a single short breath-hold. Full recovery of the longitudinal magnetisation between sequential inversion pulses is not achieved, but conditional interpretation of samples for reconstruction of T1-maps is used to yield accurate measurements, and this algorithm is implemented directly on the scanner. We performed computer simulations for 100ms<T1<2.7s and heart rates 40-100bpm followed by phantom validation at 1.5T and 3T. In-vivo myocardial T1-mapping using this method and the previous gold-standard (MOLLI) was performed in 10 healthy volunteers at 1.5T and 3T, 4 volunteers with contrast injection at 1.5T, and 4 patients with recent myocardial infarction (MI) at 3T.

RESULTS: We found good agreement between the average ShMOLLI and MOLLI estimates for T1<1200ms. In contrast to the original method, ShMOLLI showed no dependence on heart rates for long T1 values, with estimates characterized by a constant 4% underestimation for T1=800-2700ms. In-vivo, ShMOLLI measurements required 9.0+/-1.1s (MOLLI=17.6+/-2.9s). Average healthy myocardial T1s by ShMOLLI at 1.5T were 966+/-48ms (mean+/-SD) and 1166+/-60ms at 3T. In MI patients, the T1 in unaffected myocardium (1216+/-42ms) was similar to controls at 3T. Ischemically injured myocardium showed increased T1=1432+/-33ms (p<0.001). The difference between MI and remote myocardium was estimated 15% larger by ShMOLLI than MOLLI (p<0.04) which suffers from heart rate dependencies for long T1. The in-vivo variability within ShMOLLI T1-maps was only 14% (1.5T) or 18% (3T) higher than the MOLLI maps, but the MOLLI acquisitions were twice longer than ShMOLLI acquisitions.

CONCLUSIONS: ShMOLLI is an efficient method that generates immediate, high-resolution myocardial T1-maps in a short breath-hold with high precision. This technique provides a valuable clinically applicable tool for myocardial tissue characterisation.

PMID: 21092095

Urban Particulate Matter Air Pollution is Associated With Subclinical Atherosclerosis: Results from the HNR (Heinz Nixdorf Recall) Study

OBJECTIVES: The aim of this study was to investigate the association of long-term residential exposure to fine particles with carotid intima-media thickness (CIMT). Experimental and epidemiological evidence suggest that long-term exposure to air pollution might have a causal role in atherogenesis, but epidemiological findings are still inconsistent. We investigate whether urban particulate matter (PM) air pollution is associated with CIMT, a marker of subclinical atherosclerosis.

METHODS: We used baseline data (2000 to 2003) from the HNR (Heinz Nixdorf Recall) study, a population-based cohort of 4,814 participants, 45 to 75 years of age. We assessed residential long-term exposure to PM with a chemistry transport model and measured distance to high traffic. Multiple linear regression was used to estimate associations of air pollutants and traffic with CIMT, adjusting for each other, city of residence, age, sex, diabetes, and lifestyle variables.

RESULTS: Median CIMT of the 3,380 analyzed participants was 0.66 mm (interquartile range 0.16 mm). An interdecile range increase in PM(2.5) (4.2 μg/m(3)), PM(10) (6.7 μg/m(3)), and distance to high traffic (1,939 m) was associated with a 4.3% (95% confidence interval [CI]: 1.9% to 6.7%), 1.7% (95% CI: -0.7% to 4.1%), and 1.2% (95% CI: -0.2% to 2.6%) increase in CIMT, respectively.

CONCLUSIONS: Our study shows a clear association of long-term exposure to PM(2.5) with atherosclerosis. This finding strengthens the hypothesized role of PM(2.5) as a risk factor for atherogenesis.

PMID: 21087707

Longitudinal and Circumferential Strain Rate, Left Ventricular Remodeling, and Prognosis After Myocardial Infarction

OBJECTIVES: We sought to investigate the clinical prognostic value of longitudinal and circumferential strain (S) and strain rate (SR) in patients after high-risk myocardial infarction (MI). Left ventricular (LV) contractile performance after MI is an important predictor of long-term outcome. Tissue deformation imaging might more closely reflect myocardial contractility than traditional measures of systolic functions.

METHODS: The VALIANT (Valsartan in Acute Myocardial Infarction Trial) Echo study enrolled 603 patients with LV dysfunction, heart failure, or both 5 days after MI. We measured global peak longitudinal S and systolic SR (SRs) from apical 4- and 2-chamber views and global circumferential S and SRs from parasternal short-axis view with speckle tracking software (Velocity Vector Imaging, Siemens, Inc., Mountain View, California). We related global S and SRs to LV remodeling at 20-month follow-up and to clinical outcomes.

RESULTS: Both longitudinal (mean: -5.1 ± 1.6 100/ms) and circumferential SRs (mean: -8.0 ± 2.8 100/ms) were predictive of death or hospital stay for heart failure (hazard ratio: 2.4, 95% confidence interval [CI]: 2.0 to 3.1, p < 0.001; hazard ratio: 1.3, 95% CI: 1.2 to 1.4, p < 0.001, respectively) after adjustment for clinical covariates by Cox proportional hazards, and longitudinal SRs further improved in predicting 18-month survivor on a model based on clinical and standard echocardiographic measures (increase in area under the receiver-operator characteristic curve: 0.13, p = 0.009). With multivariable logistic regression, circumferential SRs, but not longitudinal SRs, was strongly predictive of remodeling (odds ratio: 1.3, 95% CI: 1.1 to 1.4, p < 0.001).

CONCLUSIONS: Both longitudinal and circumferential SRs were independent predictors of outcomes after MI, whereas only circumferential SRs was predictive of remodeling, suggesting that preserved circumferential function might serve to restrain ventricular enlargement after MI.

PMID: 21087709

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

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