Rekha Raju

The Impact of Integration of a Multidetector Computed Tomography Annulus Area Sizing Algorithm on Outcomes of Transcatheter Aortic Valve Replacement A Prospective, Multicenter, Controlled Trial

OBJECTIVES This study prospectively investigated the impact of integration of a multidetector computed tomography (MDCT) annular area sizing algorithm on transcatheter aortic valve replacement (TAVR) outcomes. BACKGROUND Appreciation of the 3-dimensional, noncircular geometry of the aortic annulus is important for transcatheter heart valve (THV) sizing. METHODS Patients being evaluated for TAVR in 4 centers underwent pre-procedural MDCT. Recommendations for balloon-expandable THV size selection were based on an MDCT sizing algorithm with an optimal goal of modest annulus area oversizing (5% to 10%). Consecutive patients who underwent TAVR with the algorithm (MDCT group) were compared with consecutive patients without the algorithm (control group). The primary endpoint was the incidence of more than mild paravalvular regurgitation (PAR), and the secondary endpoint was the composite of in-hospital death, aortic annulus rupture, and severe PAR. RESULTS Of 266 patients, 133 consecutive patients underwent TAVR (SAPIEN XT THV) in the MDCT group and 133 consecutive patients were in the control group. More than mild PAR was present in 5.3% (7 of 133) of the MDCT group and in 12.8% (17 of 133) in the control group (p = 0.032). The combined secondary endpoint occurred in 3.8% (5 of 133) of the MDCT group and in 11.3% (15 of 133) of the control group (p = 0.02), driven by the difference of severe PAR. CONCLUSIONS The implementation of an MDCT annulus area sizing algorithm for TAVR reduces PAR. Three-dimensional aortic annular assessment and annular area sizing should be considered for TAVR.

Underexpansion and Ad Hoc Post-Dilation in Selected Patients Undergoing Balloon-Expandable Transcatheter Aortic Valve Replacement

OBJECTIVES This study sought to assess the clinical outcomes and hemodynamic performance associated with a strategy of underexpanding balloon-expandable transcatheter heart valves (THV) when excessive oversizing is a concern. BACKGROUND Transcatheter aortic valve replacement depends on the selection of an optimally sized THV. An undersized THV may lead to paravalvular regurgitation, whereas excessive oversizing may lead to annular injury. METHODS Patients (n = 47) who underwent transcatheter aortic valve replacement with an intentionally underexpanded THV (balloon-filling volume reduced ~10%) were compared with consecutive control patients who had nominal THV balloon deployment (n = 87). Pre- and post-procedural computed tomography imaging and echocardiography were performed to assess THV stent expansion and hemodynamics. RESULTS Underfilling resulted in THV underexpansion that was maximal at the THV inflow (85.0 ± 7.4% vs. 102.5 ± 6.2%, p < 0.001), in study versus control groups, respectively. The study group received larger THV, although annular injury was not observed. Post-dilation was required in 10.6% and 4.6% of patients of the study and control groups, respectively (p = 0.165). Echocardiographic THV area, gradient, paravalvular regurgitation, and in-hospital outcomes were similar. CONCLUSIONS Intentionally underexpanding balloon-expandable THV by underfilling the deployment balloon did not adversely affect procedural clinical outcomes, THV gradients, or THV areas. A strategy of underexpansion, with post-dilation as necessary, might play in role in reducing the risk of annular injury and paravalvular regurgitation in selected patients.

Diagnostic accuracy and discrimination of ischemia by fractional flow reserve CT using a clinical use rule: Results from the Determination of Fractional Flow Reserve by Anatomic Computed Tomographic Angiography study

BACKGROUND Fractional flow reserve (FFR) is the gold standard for determining lesion-specific ischemia. Computed FFRCT derived from coronary CT angiography (coronary CTA) correlates well with invasive FFR and accurately differentiates between ischemia-producing and nonischemic lesions. The diagnostic performance of FFRCT when applied in a clinically relevant way to all vessels ≥ 2 mm in diameter stratified by sex and age has not been previously examined. METHODS Two hundred fifty-two patients and 407 vessels underwent coronary CTA, FFRCT, invasive coronary angiography, and invasive FFR. FFRCT and FFR ≤ 0.80 were considered ischemic, whereas CT stenosis ≥ 50% was considered obstructive. The diagnostic performance of FFRCT was assessed following a prespecified clinical use rule which included all vessels ≥ 2 mm in diameter, not just those assessed by invasive FFR measurements. Stenoses <30% were assigned an FFR of 0.90, and stenoses >90% were assigned an FFR of 0.50. Diagnostic performance of FFRCT was stratified by vessel diameter, sex, and age. RESULTS By FFR, ischemia was identified in 129 of 252 patients (51%) and in 151 of 407 vessels (31%). Mean age (± standard deviation) was 62.9 ± 9 years, and women were older (65.5 vs 61.9 years; P = .003). Per-patient diagnostic accuracy (83% vs 72%; P < .005) and specificity (54% vs 82%, P < .001) improved significantly after application of the clinical use tool. These were significantly improved over standard coronary CTA values before application of the clinical use rule. Discriminatory power of FFRCT also increased compared with baseline (area under the receiver operating characteristics curve [AUC]: 0.93 vs 0.81, P < .001). Diagnostic performance improved in both sexes with no significant differences between the sexes (AUC: 0.93 vs 0.90, P = .43). There were no differences in the discrimination of FFRCT after application of the clinical use rule when stratified by age ≥ 65 or <65 years (AUC: 0.95 vs 0.90, P = .10). CONCLUSIONS The diagnostic accuracy and discriminatory power of FFRCT improve significantly after the application of a clinical use rule which includes all clinically relevant vessels >2 mm in diameter. FFRCT has similar diagnostic accuracy and discriminatory power for ischemia detection in men and women irrespective of age using a cut point of 65 years.

Findings on Thoracic Computed Tomography Scans and Respiratory Outcomes in Persons with and without Chronic Obstructive Pulmonary Disease: A Population-Based Cohort Study

Background Thoracic computed tomography (CT) scans are widely performed in clinical practice, often leading to detection of airway or parenchymal abnormalities in asymptomatic or minimally symptomatic individuals. However, clinical relevance of CT abnormalities is uncertain in the general population. Methods We evaluated data from 1361 participants aged ≥40 years from a Canadian prospective cohort comprising 408 healthy never-smokers, 502 healthy ever-smokers, and 451 individuals with spirometric evidence of chronic obstructive pulmonary disease (COPD) who had thoracic CT scans. CT images of subjects were visually scored for respiratory bronchiolitis(RB), emphysema(E), bronchial-wall thickening(BWT), expiratory air-trapping(AT), and bronchiectasis(B). Multivariable logistic regression models were used to assess associations of CT features with respiratory symptoms, dyspnea, health status as determined by COPD assessment test, and risk of clinically significant exacerbations during 12 months follow-up. Results About 11% of life-time never-smokers demonstrated emphysema on CT scans. Prevalence increased to 30% among smokers with normal lung function and 36%, 50%, and 57% among individuals with mild, moderate or severe/very severe COPD, respectively. Presence of emphysema on CT was associated with chronic cough (OR,2.11; 95%CI,1.4–3.18); chronic phlegm production (OR,1.87; 95% CI,1.27–2.76); wheeze (OR,1.61; 95% CI,1.05–2.48); dyspnoea (OR,2.90; 95% CI,1.41–5.98); CAT score≥10(OR,2.17; 95%CI,1.42–3.30) and risk of ≥2 exacerbations over 12 months (OR,2.17; 95% CI, 1.42–3.0). Conclusions Burden of thoracic CT abnormalities is high among Canadians ≥40 years of age, including never-smokers and smokers with normal lung function. Detection of emphysema on CT scans is associated with pulmonary symptoms and increased risk of exacerbations, independent of smoking or lung function.

Aortic dissection in a patient with a dilated aortic root following tetralogy of Fallot repair

With improved longevity, aortic root dilation has been increasingly recognized among patients with tetralogy of Fallot (TOF). Aortic dissection is thought to be rare with only three previous cases [1,3,2] reported in the literature. We describe the case of a patient who presented following aortic root dissection late after TOF repair. This 60 year old male had TOF repair at age 14, and was known to have a dilated aortic root. Infrequent (five yearly) transthoracic echocardiograms from 1999 to 2011 showed no progressive aortic root dilation although the ascending aorta was not always well visualized. There was no significant residual valvular disease, outflow tract obstruction or ventricular septal defect. Computed tomography (CT) of the aorta in January 2012 measured a transsinus diameter of 53 mm (24 mm/m; normal b20 mm/m) and proximal ascending aorta diameter of 49 mm which were similar to measurements obtained on an ascending aortogram a few months later. Apart from being obese (height 173 cm, weight 100 kg), he had no comorbidities and was on no regular medications. He presented in April 2013 with a two week history of new onset class III-IV dyspnea that was preceded by an episode of acute chest pain lasting three hours. Clinically he had left ventricular failure with a loud aortic regurgitant murmur, bilateral pleural effusions and a serum BNP 1400 ng/L (normal b40 ng/L). A CT of the aorta (Fig. 1) showed a trans-sinus diameter of 55 mm but there was now a limited dissection involving the right coronary cusp causing severe aortic regurgitation confirmed by echocardiography. He underwent a Bentall operation. Various hypotheses have been proposed for the mechanism of aortic root dilatation in this group of patients including: increased flow through the aorta due to right to left shunting before repair [4]; embryological defects of spiral septum growth leading to a larger aortic diameter at the expense of the pulmonary artery [5]; and an intrinsic aortopathy related to cystic medial degeneration [5]. The prevalence of aortic root dilation in TOF patients has been reported in a few studies and ranges between 15 and 87% depending on the definitions used [6], and when defined as an observed-to-expected ratio indexed to body surface area and age, was only present in 6.6% of patients [6]. In this case, the indexed observed-to-expected aortic dimension was increased at 1.58. In the previous three reports of aortic dissection in repaired TOF, the aortic dimensions were 71 mm [1], 93 mm [3] and 70 mm [2]; significantly larger than in this case. There is no consensus as to how TOF patients with aortic root dilation should be managed. Intervention when the ascending aorta reaches 55 mm [4] has been suggested as aortic dilatation is associated with increased stiffness and hence increased risk of aortic dissection [7]. The low number of reported cases may suggest

Sequential Right and Left Ventricular Assessment in Posttetralogy of Fallot Patients with Significant Pulmonary Regurgitation.

BACKGROUND The natural history of right ventricular (RV) and left ventricular (LV) size and function among adults with tetralogy of Fallot (TOF) repair and hemodynamically significant pulmonary regurgitation (PR) is not known. The main aim of this study was to determine changes in RV and LV size and function over time in an adult population with TOF repair and hemodynamically significant pulmonary regurgitation. METHODS Forty patients with repaired TOF and hemodynamically significant PR were included. These patients were identified on the basis of having more than one CMR between January 2008 and 2015. Patients with a prosthetic pulmonary valve or any cardiac intervention between CMR studies were excluded. Rate of progression (ROP) of RV dilation was determined for both indexed right ventricular end-systolic volume (RVESVi) and indexed right ventricular end-diastolic volume (RVEDVi), and calculated as the difference between the last and first volumes divided by the number of years between CMR#1 and CMR#2. Subjects were also divided into two groups based on the distribution of the ROP of RV dilation: Group I-rapid ROP (>50th percentile) and Group II-slower ROP (≤50th percentile). RESULTS The interval between CMR#1 and CMR#2 was 3.9 ± 1.7 years (range 1-8 years). We did find a significant change in RVEDVi and RVESVi over this time period, although the magnitude of change was small. Nine patients (23%) had a reduction in right ventricular ejection fraction (RVEF) by greater than 5%, 13 patients (33%) had an increase in RVEDVi by greater than 10 mL/m2 and seven patients (18%) had an increase in RVESVi by greater than 10 mL/m2 . Median ROP for RVEDVi was 1.8 (range -10.4 to 21.8) mL/(m2 year); RVESVi 1.1 (range -5.8 to 24.5) mL/(m2 year) and RVEF -0.5 (range -8 to 4)%/year. Patients with a rapid ROP had significantly larger RV volumes at the time of CMR#1 and lower RVEF as compared to the slow ROP group. There was no overall significant change in LVEDVi, LVESVi, or LVEF over this time period. CONCLUSIONS We have demonstrated, in a small population of patients with hemodynamically significant PR, that there is a small increase in RV volumes and decrease in RVEF over a mean 4-year period. We believe it to be reasonable practice to perform CMR at least every 4 years in asymptomatic patients with repaired TOF and hemodynamically significant PR. We found that LV volumes and function remained stable during the study period, suggesting that significant progressive LV changes are less likely to occur over a shorter time period. Our results inform a safe standardized approach to monitoring adults with hemodynamically significant PR post TOF repair and assist in planning allocation of this expensive and limited resource.

Safety and efficiency of outpatient versus emergency department-based coronary CT angiography for evaluation of patients with potential ischemic chest pain☆

BACKGROUND While coronary CT angiography (coronary CTA) may be comparable to standard care in diagnosing acute coronary syndrome (ACS) in emergency department (ED) chest pain patients, it has traditionally been obtained prior to ED discharge and a strategy of delayed outpatient coronary CTA following an ED visit has not been evaluated. OBJECTIVE To investigate the safety of discharging stable ED patients and obtaining outpatient CCTA. METHODS At two urban Canadian EDs, patients up to 65 years with chest pain but no findings indicating presence of ACS were further evaluated depending upon time of presentation: (1) ED-based coronary CTA during normal working hours, (2) or outpatient coronary CTA within 72 hours at other times. All data were collected prospectively. The primary outcome was the proportion of patients who had an outpatient coronary CTA ordered and had a predefined major adverse cardiac event (MACE) between ED discharge and outpatient CT; secondary outcome was the ED length of stay in both groups. RESULTS From July 1, 2012 to June 30, 2014, we enrolled 521 consecutive patients: 350 with outpatient CT and 171 with ED-based CT. Demographics and risk factors were similar in both cohorts. No outpatient CT patients had a MACE prior to coronary CTA. (0.0%, 95% CI 0 to 0.9%) The median length of stay for ED-based evaluation was 6.6 hours (interquartile range 5.4 to 8.3 hours) while the outpatient group had a median length of stay of 7.0 hours (IQR 6.0 to 9.8 hours, n.s.). CONCLUSIONS In ED chest pain patients with a low risk of ACS, performing coronary CTA as an outpatient may be a safe strategy.

Caseous calcification of the mitral annulus

A 61-year-old asymptomatic woman was referred for echocardiography to evaluate recently detected systolic murmur. Transthoracic echocardiography revealed an echodense obstructive mass in the left ventricular outflow tract of unclear origin. Subsequent transesophageal echo suggested an intracardiac calcified tumor and recommended surgical excision. Contrast-enhanced cardiac computed tomography (CT) confirmed a well-defined lobulated mass adherent to the anterior mitral valve leaflet, the non-enhanced scout view revealed marked hyper-attenuation confirming diffuse calcification. Caseous calcification was diagnosed and surgery was deferred. Caseous calcification is typically benign and most commonly involves the posterior mitral annulus. Our patient displayed an atypical location of exuberant mitral annular calcification.

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.

THE IMPACT OF INTEGRATION OF A COMPUTED TOMOGRAPHY ANNULUS AREA SIZING ALGORITHM ON CLINICAL OUTCOMES OF TRANSCATHETER AORTIC VALVE REPLACEMENT: A PROSPECTS. MULTICENTER, CONTROLLED TRIAL

Appreciation of the complex non–circular geometry of the aortic annulus by three–dimensional imaging is important for accurate transcatheter heart valve (THV) size selection. We prospectively investigated the impact of integration of a multidetector computed tomography (MDCT) annular area sizing