Systolic Anterior Motion of the Mitral Valve in the Presence of Annular Calcification.

BACKGROUND: Mitral annular calcification (MAC) has been reported as a possible cause of systolic anterior motion (SAM) of the mitral valve and dynamic left ventricular outflow tract (LVOT) obstruction. While morphologic features predisposing to SAM in other clinical settings have been described, patients with MAC+SAM have not been systematically investigated. We hypothesized that bulky calcium deposits in the mitral annulus could displace the valve toward the septum, thus promoting development of SAM. METHODS: We studied 30 patients with severe MAC who had SAM with septal contact. Three comparator groups (matched for age and sex) were developed: 30 controls without MAC or SAM, 30 with severe MAC but no SAM, and 30 with SAM but no MAC. RESULTS: Significant differences were found across groups for mitral valve coaptation point-septal distance (CSD), anterior mitral leaflet (AML) length, left ventricular diastolic dimension, and ejection fraction. Comparing all MAC subjects (n = 60) with controls, CSD was less (20.5 ± 4.1 vs 23.2 ± 3.7 mm, P = .003) and ejection fraction was higher (67.7% ± 7.8% vs 60.9% ± 6.4%, P < .0001) in MAC patients. Within MAC subjects AML was longer (21.9 ± 3.0 vs 17.4 ± 2.2 mm, P < .0001) and CSD was smaller (18.0 ± 2.7 vs 23.1 ± 3.6 mm, P < .0001) when SAM was present despite similar height of the calcium bar in the 2 MAC groups (12.4 ± 2.9 vs 11.1 ± 3.1 mm, P = .11). Regression analysis confirmed AML length and CSD as independent predictors of SAM. MAC+SAM patients also had more echocardiographic risk factors for SAM (acute aortomitral angle, small LVOT, long AML, small CSD, and presence of a septal bump) than MAC/no-SAM patients (3.4 ± 0.9 vs 1.8 ± 1.0, P < .0001). CONCLUSIONS: Bulky MAC appears to contribute to dynamic LVOT obstruction when it accumulates in such a way that the mitral valve is displaced anteriorly toward the septum. However, other features are also associated with SAM in these patients, particularly a long AML. A combination of morphologic features and favorable hemodynamics may be needed for SAM to develop in patients with severe MAC.

3D Printing of Subclavian Artery: Utility for Preprocedural Planning and Correlation With Subclavian Artery Percutaneous Vascular Interventions.

BACKGROUND: Three-dimensional (3D) printing for subclavian artery (SA) percutaneous vascular interventions (PVI) may allow superior understanding of patient specific complex anatomy and aid with preprocedural planning. METHODS: Five patients with computed tomography angiography (CTA) of the neck who underwent SA PVI were queried retrospectively. 3D printing of aortic arch and great vessels was accomplished with 3D slicer software and painted with acrylic paint to highlight anatomic features. The aortic arch type and implications for preprocedural planning for SA interventions including complex chronic total occlusion (CTO) lesions were determined. Comparisons were made with SA angiograms and 3D-CTA. RESULTS: Of the 5 patients, type I (n = 2), type II (n = 1), and type III (n = 2) aortic arches were identified. Proximal and distal reference vessel size and total lesion length were determined using a digital millimeter caliper and correlated with intraprocedural balloons and stents. In 3D-printed models (3D-PMs) of patients with SA-CTO (n = 2), cap morphology (tapered vs blunt) and distal vessel filling were visualized, permitting optimal arterial access site selection for successful cap crossing. The vertebral arteries (VAs) were also 3D printed which further allowed the ability to delineate optimal stent deployment site (proximal or distal to VA), a common dilemma that is faced intraprocedurally. The 3D-PMs also allowed preprocedural precision in stent and balloon size and length, potentially leading to procedural efficiency and cost-effectiveness. CONCLUSION: 3D printing of aortic arch and great vessel anatomy for SA-PVI allows multiple procedure-related factors to be predicted in advance, translating to decrease in contrast volume, radiation time, procedure and fluoroscopic time, thereby improving procedure and cost efficiency.

3D Printing for Mesenteric Artery Endovascular Interventions: Feasibility and Utility for Preprocedural Planning and Angiographic Correlation.

BACKGROUND: Three-dimensional (3D) printing of mesenteric artery (MA) anatomy preprocedurally for endovascular interventions can allow strategic preprocedure planning and improve procedure-related clinical outcomes. METHODS: Three patients with computed tomography angiography (CTA) of the abdomen and pelvis who subsequently underwent MA interventions were 3D printed retrospectively, and 2 patients with symptoms and severe MA stenosis on CTA, who had not undergone intervention, were 3D printed for procedure-related planning and anatomy-specific implications. The 3D-printed models (3D-PMs) were painted with acrylic paint to highlight anatomy. Reference vessel size, lesion length (LL), and renal artery (RA) to MA distance were determined using a digital millimeter caliper. RESULTS: Each of the 5 patients with variable anatomy, including an MA chronic total occlusion (CTO), were successfully 3D printed. A digital caliper allowed determination of vessel size, LL, and RA to MA distance, which were then compared with intraprocedural MA angiograms and intravascular imaging when available. Further complex anatomies, such as intraprocedural navigation in the setting of prior abdominal aortic endograft and CTO assessment with relevance to cap morphology, small branch arteries, and collateral flow, were also successfully 3D printed. CONCLUSION: Preprocedural 3D printing of MA anatomy for interventions can theoretically lead to decreases in contrast use, radiation dose, and fluoroscopic and procedural times, as well as enhance comprehension of complex patient-specific anatomy.

Obstructive sleep apnea in patients with acute aortic dissection.

BACKGROUND: Obstructive sleep apnea (OSA) imposes an afterload burden on the left ventricle and increases the pressure gradient across the aortic wall. Thus, OSA may increase the risk for aortic dissection (AD). METHODS: This study enrolled 40 subjects with acute AD from four institutions; 37 completed the modified Berlin Questionnaire and 31 underwent attended overnight polysomnography. Aortic diameter was measured on a computed tomography scan at seven locations from the sinotubular junction to the diaphragm. RESULTS: Twenty-seven subjects had type A dissection; 13 had type B. In those who had polysomnography apnea-hypopnea index (AHI) ranged from 0.7 to 89. Prevalence of OSA (AHI ≥ 5) was 61%. Nocturnal presentation (10 p.m.-7 a.m.) did not differ by presence/absence of OSA. The modified Berlin Questionnaire was not predictive of the presence of OSA. Among type A subjects with polysomnography (n = 23), aortic diameters at all locations were greater in the OSA group though differences were not statistically significant. Summating aortic diameters at the seven locations also yielded a numerically larger mean value in the OSA group versus the non-OSA group. CONCLUSIONS: In this sample of patients with acute dissection, OSA was prevalent but was not associated with a nocturnal presentation. The presence of underlying OSA may be associated with larger aortic diameters at the time of dissection compared to patients without OSA. Though differences did not meet statistical significance the current series is limited by small numbers.

3D Printing of Renal Arteries for Endovascular Interventions: Feasibility, Utility, and Correlation With Renal Arteriograms.

BACKGROUND: Three-dimensional (3D) printing technology is increasingly being utilized for preprocedural planning of interventional procedures. However, utility of 3D models of obstructive and clinically relevant renal artery disease has not been evaluated and could potentially assist in preprocedural planning of renal artery endovascular interventions. METHODS: Five patients with computed tomography angiography (CTA) of abdomen and pelvis who also subsequently underwent renal artery interventions were 3D printed retrospectively. Standard 3D slicer software was used to segment out descending aorta, renal artery, and renal anatomy to create a computer aided image. The 3D-printed models (3D-PMs) were painted with acrylic paint to highlight anatomic features for comparison with renal arteriograms and 3D-CTA to aid in endovascular interventions. RESULTS: 3D-PMs were successfully produced in diverse renal artery pathology: atherosclerotic disease, fibromuscular dysplasia, in-stent restenosis, and bilateral renal artery stenosis. Renal artery ostium angulation and optimal axial guiding catheter engagement were elucidated. Additionally, reference vessel size and lesion length were measured using digital millimeter calipers. Renal arteriogram along with renal interventional devices utilized during each case were compared for size correlation, reproducibility, and clinical utility. CONCLUSION: Preprocedural 3D printing of renal artery anatomy requiring endovascular intervention could allow for better appreciation of renal anatomy and could serve as an adjunctive tool to minimize use of contrast, fluoroscopy, and procedure time.

3D Printing of Carotid Artery and Aortic Arch Anatomy: Implications for Preprocedural Planning and Carotid Stenting.

BACKGROUND: Carotid artery stenting (CAS) has been associated with increased periprocedural stroke in comparison with carotid endarterectomy (CEA). Three-dimensional (3D) printing of aortic arch and carotid artery may aid with preprocedural planning and adaptive learning, possibly reducing procedure-related complications. METHODS: Five CAS cases with available computed tomography angiography (CTA) were retrospectively evaluated and 3D-printed models (3D-PMs) were made. One additional case that was 3D printed preprocedurally provided prospective analysis. Standard 3D printing software was used to create a computer-aided image from CTA series that were 3D printed. The models were painted with acrylic paint to highlight anatomical features. The type of aortic arch, common carotid artery (CCA) to internal carotid artery (ICA) angle, and ICA distal landing zone for embolic protection device (EPD) were analyzed. In addition, stent and EPD sizing was determined preprocedurally for the prospective case. Comparisons of 3D-PM were made with 3D-CTA reconstruction and carotid angiography. RESULTS: Of 6 cases, 2 had type III and 4 had type I aortic arches. One case, a failed endovascular approach from femoral artery access site requiring reattempt via right brachial artery, had a CCA to ICA angle >60° and a tortuous innominate artery and distal ICA for EPD. The remaining 5 cases had straight distal landing zones for EPD and <60° CCA to ICA angles with successful first endovascular attempt. Additionally, vessel-specific stent and EPD sizing was appropriately chosen for the 1 prospective case. CONCLUSIONS: 3D-PM for CAS offers added value compared with CTA by providing improved perceptual and visual understanding of 3D anatomy.

Patient-Specific Coronary Artery Bypass Graft 3D Printing: Implications for Procedural Planning in Complex Percutaneous Coronary Interventions.

BACKGROUND: Three-dimensional (3D) printing technology has seen tremendous growth in augmenting didactics, research, and preprocedural planning with structural heart procedures. Limited investigative efforts have been made in other areas of the cardiovascular spectrum. 3D-printed models (PMs) of anatomically complex coronary artery bypass graft (CABG) patients from coronary computed tomography angiography (CCTA) have implications for adaptive learning and preprocedural planning. METHODS: Five patients with CCTA who underwent subsequent coronary angiography were 3D printed for retrospective comparisons. Standard slicer software was used to create a computer-aided image of the ascending aorta, native coronary arteries, bypass grafts, aortic arch, and great vessels and 3D printed using polylactic acid filament. The models were painted with acrylic paint to highlight anatomical features and comparison was made with coronary angiography and 3D-CTA images. RESULTS: All occluded vein grafts, left and right internal mammary artery (IMA) grafts, patent saphenous vein grafts, along with distal graft anastomotic sites, were accurately 3D printed. In cases with chronic total occlusions (CTOs), ambiguous ostial caps, mid or distal vessel chronic occlusions, and occlusions seen as CTOs on coronary angiography were 3D printed showing either distal vessel reconstitution via collaterals or complete arterial filling seen in a setting of calcification, microchannels, and collateral flow. Lastly, 3D printing of the aortic root and great vessels allowed for better appreciation of vessel tortuosity to aid in the cannulation of IMA grafts and optimizing engagement with diagnostic and guiding catheters. CONCLUSIONS: 3D printing of anatomically complex CABG patients has the potential to assist with preprocedural planning and operator understanding of complex coronary anatomy.

Energy loss associated with in-vitro modeling of mitral annular calcification.

INTRODUCTION: Study aims were to compare hemodynamics and viscous energy dissipation (VED) in 3D printed mitral valves-one replicating a normal valve and the other a valve with severe mitral annular calcification (MAC). Patients with severe MAC develop transmitral gradients, without the commissural fusion typifying rheumatic mitral stenosis (MS), and may have symptoms similar to classical MS. A proposed mechanism relates to VED due to disturbed blood flow through the diseased valve into the ventricle. METHODS: A silicone model of a normal mitral valve (MV) was created using a transesophageal echocardiography dataset. 3D printed calcium phantoms were incorporated into a second valve model to replicate severe MAC. The synthetic MVs were tested in a left heart duplicator under rest and exercise conditions. Fine particles were suspended in a water/glycerol blood analogue for particle image velocimetry calculation of VED. RESULTS: Catheter mean transmitral gradients were slightly higher in the MAC valve compared to the normal MV, both at rest (3.2 vs. 1.3 mm Hg) and with exercise (5.9 vs. 5.0 mm Hg); Doppler gradients were 2.7 vs. 2.1 mm Hg at rest and 9.9 vs 8.2 mm Hg with exercise. VED was similar between the two valves at rest. During exercise, VED increased to a greater extent for the MAC valve (240%) versus the normal valve (127%). CONCLUSION: MAC MS is associated with slightly increased transmitral gradients but markedly increased VED during exercise. These energy losses may contribute to the exercise intolerance and exertional dyspnea present in MAC patients.

Aortic stenosis calcium scoring in a racially mixed sample.

Aortic stenosis (AS) is common and increasing in prevalence as the population ages. Using computed tomography (CT) to quantify aortic valve calcification (AVC) it has been reported that men have greater degrees of calcification than women among subjects with severe AS. These data, however, were derived in largely Caucasian populations and have not been verified in non-Caucasian subjects. This retrospective study identified 137 patients with severe AS who underwent valve replacement and had CT scans within 6 months prior to surgery. AVC scores were compared between men and women, both in the entire sample and in racial subgroups. 52% of subjects were male and 62.8% were non-Caucasian. Mean AVC score for the entire cohort was 3062.08±2097.87 with a range of 428-13,089. Gender differences in aortic valve calcification were found to be statistically significant with an average AVC score of 3646±2422 in men and 2433±1453 in women (p=0.001). On multivariate analysis, gender remained significantly associated with AVC score both in the entire sample (p=0.014) and in the non-Caucasian subgroup (p=0.008). Mean AVA was significantly greater in males than females but this difference disappeared when AVA was indexed to BSA (p=0.719). AVA was not different between racial groups (p=0.369). In this research we observed that among subjects with severe AS men have higher AVC scores than women regardless of racial background. This is consistent with previous studies in predominantly Caucasian populations.

Color Doppler Splay: A Clue to the Presence of Significant Mitral Regurgitation.

BACKGROUND: The authors describe a previously unreported Doppler signal associated with mitral regurgitation (MR) as imaged using transthoracic echocardiography. Horizontal "splay" of the color Doppler signal along the atrial surface of the valve may indicate significant regurgitation when the MR jet otherwise appears benign. METHODS: Splay was defined as a nonphysiologic arc of color centered at the point at which the MR jet emerges into the left atrium. The authors present a series of 10 cases of clinically significant MR (moderately severe or severe as defined by transesophageal echocardiography) that were misclassified on transthoracic echocardiography as less than moderate. The splay signal was present on at least one standard transthoracic view in each case. To better characterize the splay signal, two groups were created from existing clinically driven transthoracic echocardiograms: 100 consecutive patients with severe MR and 100 with mild MR. RESULTS: Splay was present in the majority of severe MR cases (81%) regardless of vendor machine, ejection fraction, or MR etiology. Splay was particularly prevalent among patients with wall-hugging jets (28 of 30 [93%]). In patients with mild MR, splay was present less often (16%), on fewer frames per clip, and had smaller dimensions compared with severe MR. Color scale did not differ between subjects with and those without splay, but color gain was higher when splay was present (P = .04). Machine settings were further explored in a single subject with prominent splay: increasing transducer frequency reduced splay, while increasing color gain increased it. CONCLUSIONS: The authors describe a new transthoracic echocardiographic sign of MR. Horizontal splay may be a clue to the presence of severe MR when the main body of the jet is out of the imaging plane. Splay is likely generated as a side-lobe artifact due to a high-flux regurgitant jet.

Usefulness of the Echocardiographic Calcium Score to Refine Risk of Major Adverse Cardiovascular Events Beyond the Traditional Framingham Risk Score.

Echocardiographic calcifications are associated with major adverse cardiovascular events (MACE). A recently described semiquantitative Global Cardiac Calcium Score (GCCS) has been associated with mortality and stroke, with increasing scores associated with increasing risk. This score assigns points for calcium in the aortic root and valve, mitral valve and annulus, and submitral apparatus, with additional points for restricted leaflet mobility. We tested the hypothesis that the GCCS could improve prediction of MACE beyond traditional risk scores. This was a retrospective study of 216 subjects from a general echocardiography database (mean age 59 ± 15; 51% male). Follow-up was 3.8 ± 1.7 years. The Framingham Risk Score (FRS) and Pooled Cohort Equations (PCE) were applied to each patient. Mean GCCS was 3.2 ± 2. In the total cohort, GCCS predicted MACE (myocardial infarction, stroke, all-cause mortality), even after adjusting for FRS (odd ratio 1.19, p = 0.03). There were 106 subjects (49%) in the low-risk FRS group, 71 (33%) in the intermediate-risk group, and 39 (18%) in the high-risk group. GCCS ≥3 was associated with increased MACE (vs <3) in the low-risk group (p = 0.03), while GCCS <3 was associated with decreased MACE (vs ≥3) in the high-risk group (p = 0.04). When applied to the PCE risk estimate (dichotomized at <7.5% vs ≥7.5%) the GCCS similarly refined risk prediction. In conclusion, the semiquantitative GCCS appears to be a marker of additional unaccounted risk factors; it is easily applied and can further stratify risk of MACE beyond traditional FRS or PCE estimates.

CT based 3D printing is superior to transesophageal echocardiography for pre-procedure planning in left atrial appendage device closure.

Accurate assessment of the left atrial appendage (LAA) is important for pre-procedure planning when utilizing device closure for stroke reduction. Sizing is traditionally done with transesophageal echocardiography (TEE) but this is not always precise. Three-dimensional (3D) printing of the LAA may be more accurate. 24 patients underwent Watchman device (WD) implantation (71 ± 11 years, 42% female). All had complete 2-dimensional TEE. Fourteen also had cardiac computed tomography (CCT) with 3D printing to produce a latex model of the LAA for pre-procedure planning. Device implantation was unsuccessful in 2 cases (one with and one without a 3D model). The model correlated perfectly with implanted device size (R2 = 1; p < 0.001), while TEE-predicted size showed inferior correlation (R2 = 0.34; 95% CI 0.23-0.98, p = 0.03). Fisher's exact test showed the model better predicted final WD size than TEE (100 vs. 60%, p = 0.02). Use of the model was associated with reduced procedure time (70 ± 20 vs. 107 ± 53 min, p = 0.03), anesthesia time (134 ± 31 vs. 182 ± 61 min, p = 0.03), and fluoroscopy time (11 ± 4 vs. 20 ± 13 min, p = 0.02). Absence of peri-device leak was also more likely when the model was used (92 vs. 56%, p = 0.04). There were trends towards reduced trans-septal puncture to catheter removal time (50 ± 20 vs. 73 ± 36 min, p = 0.07), number of device deployments (1.3 ± 0.5 vs. 2.0 ± 1.2, p = 0.08), and number of devices used (1.3 ± 0.5 vs. 1.9 ± 0.9, p = 0.07). Patient specific models of the LAA improve precision in closure device sizing. Use of the printed model allowed rapid and intuitive location of the best landing zone for the device.