Impact of dual energy cardiac CT for metal artefact reduction post aortic valve replacement.

PURPOSE: Assess image quality of dual-energy (DE) and single-energy (SE) cardiac multi-detector computed tomographic (MDCT) post aortic valve replacement (AVR) on a dual source MDCT scanner. METHODS: Eighty patients with cardiac MDCT acquisitions (ECG gated, dual-source) post-surgical and transcatheter AVR were retrospectively identified. Forty DE (cohort 1) and 40 SE acquisitions (cohort 2; 100 or 120 kVp) were reviewed. Metal artefact at valve coaptation (VC) and valve insertion site (VIS), and contrast enhancement were assessed. Valve leaflet edge definition was graded on a 4-point scale by three radiologists. RESULTS: The mean percentage valve area obscured by metal artifact differed between the cohorts; cohort 1 DE blended, high keV and low keV: 14.8 %, 11.1 % and 17.8 % at VC and 16.4 %, 13 %, 20.4 % at VIS respectively. Cohort 2: 25.8 % and 33.6 % (VC and VIS); each DE reconstruction vs SE: P < 0.0001. Average contrast opacification and coefficient of variance for cohort 1: 562.9 ± 144.7, 281.1 ± 60.3 and 1132.7 ± 300.8 Hounsfield Units (HU) and 9.6 %, 10 % and 8.9 %. For cohort 2: 437.2 ± 119.2 HU and 10.8 % (P < 0.01). Average leaflet edge definition cohort 1: 2.3 ± 0.4, 2.7 ± 0.2 and 2.3 ± 0.2, and cohort 2: 2.9 ± 0.2. CONCLUSION: DE high keV renderings can result in up to 17.2 % less metal artefact compared to standard SE acquisition for cardiac CT. Contrast opacification and homogeneity is higher for DE blended and low keV renderings compared to SE acquisition with leaflet visibility preferred for low keV and blended DE renderings.

Splanchnic Nerve Block for Chronic Heart Failure.

OBJECTIVES: We hypothesized that splanchnic nerve blockade (SNB) would attenuate increased exercise-induced cardiac filling pressures in patients with chronic HF. BACKGROUND: Chronic heart failure (HF) is characterized by limited exercise capacity driven in part by an excessive elevation of cardiac filling pressures. METHODS: This is a prospective, open-label, single-arm interventional study in chronic HF patients. Eligible patients had a wedge pressure ≥15 mm Hg at rest or ≥25 mm Hg with exercise on baseline right heart catheterization. Patients underwent cardiopulmonary exercise testing with invasive hemodynamic assessment, followed by percutaneous SNB with ropivacaine. RESULTS: Nineteen patients were enrolled, 15 of whom underwent SNB. The average age was 58 ± 13 years, 7 (47%) patients were women and 6 (40%) were black. Left ventricular ejection fraction was ≤35% in 14 (93%) patients. No procedural complications were encountered. SNB reduced mean pulmonary arterial pressure at peak exercise from 54.1 ± 14.4 (pre-SNB) to 45.8 ± 17.7 mm Hg (p < 0.001) (post-SNB). Similarly, SNB reduced exercise-induced wedge pressure from 34.8 ± 10.0 (pre-SNB) to 25.1 ± 10.7 mm Hg (p < 0.001) (post-SNB). The cardiac index changed with peak exercise from 3.4 ± 1.2 (pre-SNB) to 3.8 ± 1.1 l/min/m2 (p = 0.011) (post-SNB). After SNB, patients exercised for approximately the same duration at a greater workload (33 ± 24 W vs. 50 ± 30 W; p = 0.019) and peak oxygen consumption VO2 (9.1 ± 2.5 vs. 9.8 ± 2.7 ml/kg/min; p = 0.053). CONCLUSIONS: SNB reduced resting and exercise-induced pulmonary arterial and wedge pressure with favorable effects on cardiac output and exercise capacity. Continued efforts to investigate short- and long-term effects of SNB in chronic HF are warranted. Clinical Trials Registration (Abdominal Nerve Blockade in Chronic Heart Failure; NCT03453151).

Transcatheter aortic valve replacement for patients with severe bicuspid aortic stenosis.

BACKGROUND: Patients with bicuspid aortic valve stenosis (BAV) were excluded from all the trileaflet aortic valve stenosis (TAV) pivotal trials, and therefore, their outcomes are not clearly defined. The aim of the study was to evaluate the outcomes of transcatheter aortic valve replacement (TAVR) in patients with BAV and compared them with those of TAV. METHODS: We evaluated the outcomes following TAVR of patients with BAV at our institution between April 2011 and November 2016 and compared them with the outcomes of patients with TAV treated with TAVR. The χ2 and the Mann-Whitney U tests were used to compare the groups, and a Kaplan-Meier analysis was performed to estimate long-term survival. RESULTS: TAVR was performed in a total of 567 patients, from which 50 (8.8%) had BAV and 517 (91.2%) had TAV. Patients with BAV were younger and had higher prevalence of chronic obstructive pulmonary disease, lower prevalence of coronary artery disease, higher body mass index, and lower Society of Thoracic Surgeons score (STS PROM). Patients with BAV had a slightly higher mean aortic valve gradient postoperatively (median 12 mm Hg [10-15] vs 10 [7-13], P < .001), but paravalvular aortic regurgitation was not different between the groups (> mild 4.0% vs 3.5%, P = .541). Clinical outcomes were not different between the groups, including stroke (2.0% vs 1.5, P = .567) and the 30-day all-cause mortality (6.0% vs 1.5, P = .064). The 2-year survival (82.0% vs 83.4, P = .476) was similar between the groups. CONCLUSIONS: This initial experience suggests that TAVR can be safely performed in patients with BAV, achieving similar short-term procedural and clinical outcomes when compared with patients with TAV.

Review of alternative access in transcatheter aortic valve replacement.

Transcatheter aortic valve replacement (TAVR) has surpassed surgical aortic valve replacement (SAVR) as the most common treatment strategy for severe symptomatic aortic stenosis over the past decade. As TAVR technology has continued to advance, it has been expanded from being an option only for extreme risk patients to now being the preferred option for the majority of patients with severe aortic stenosis. Recent trials have shown that TAVR is superior or non-inferior to SAVR even in patients at low surgical risk. One limitation of TAVR is the need for large bore vascular access. This has improved over time with smaller sheath sizes and improved delivery systems, but is still a significant issue in a patient population that often has many comorbidities including peripheral arterial disease. Early in the TAVR experience the only option for alternative access was transapical access, which has consistently been linked to increased procedural complications and worsened clinical outcomes. However, in recent years several centers have demonstrated the safety and efficacy of several alternative access strategies including transaxillary, transcarotid, transcaval, and direct aortic. There are no randomized data comparing these strategies, so access site approach is chosen by the multidisciplinary heart team based on patient anatomy and site expertise. We will review the current data in alternative access that in our view supports prioritizing a transaxillary or transcarotid strategy. In addition, we will describe our center's pre-procedural planning, peri-procedural approach, and propose an algorithm for alternative access.

Valve-in-Ring Transcatheter Aortic Valve Replacement After Left Ventricular Assist Device Therapy.

Aortic regurgitation after left ventricular assist device (LVAD) implantation is a well-described problem that decreases the clinical effectiveness of LVAD therapy and may eventually prompt consideration of aortic valve replacement once the regurgitation becomes severe. Transcatheter aortic valve replacement is an attractive, less invasive option compared with surgical aortic valve replacement in these patients. We report a valve-in-ring transcatheter aortic valve replacement for a patient with severe aortic regurgitation associated with LVAD destination therapy. Our case demonstrates that this approach is feasible in humans and can yield excellent clinical results.

Trends and Outcomes of Alternative-Access Transcatheter Aortic Valve Replacement.

BACKGROUND: Alternative access (AA) is still required for a significant proportion of patients undergoing transcatheter aortic valve replacement (TAVR). We sought to compare the clinical outcomes of patients undergoing AA vs transfemoral (TF) access. METHODS: We retrospectively evaluated the outcomes of patients undergoing AA-TAVR between April 2011 and November 2016, and compared them with those who had TF-TAVR. Chi-square and Mann-Whitney U-tests were used to compare the groups and Kaplan-Meier analysis was performed to estimate long-term survival. RESULTS: TAVR was performed in a total of 600 patients, of which 78 (13%) had AA and 522 (87%) had TF access. Patients undergoing AA were younger, and had higher prevalence of chronic obstructive pulmonary disease, peripheral vascular disease, prior myocardial infarction, and prior sternotomy. Greater than mild paravalvular regurgitation (4.2% vs 0.0%; P=.04) and unplanned vascular surgery (5.4% vs 1.3%; P=.09) were more frequent in the TF group. However, patients who underwent AA had longer hospital stay (median 4 days [interquartile range, 3-7 days] vs 3 days [interquartile range, 3-4 days]; P<.001) and an increased incidence of prolonged ventilation (5.1% vs 1.3%; P=.06), 30-day all-cause (5.1% vs 1.7%; P=.08), and cardiovascular mortality (5.1% vs 1.3%; P=.04). The 6-month (15.7% vs 5.7%; P<.01) and 12-month (16.7% vs 10.2%; P=.07) mortality rates were higher for patients undergoing AA. The usage of AA significantly decreased over time (P=.01), primarily driven by a decrease in transapical (P<.001) and direct aortic access (P=.02). CONCLUSIONS: AA-TAVR is associated with an increased incidence of postoperative adverse events, including mortality, when compared with those undergoing TF access.

Association of Renin-Angiotensin Inhibitor Treatment With Mortality and Heart Failure Readmission in Patients With Transcatheter Aortic Valve Replacement.

Importance: Data are lacking on the effect of a renin-angiotensin system (RAS) inhibitor prescribed after transcatheter aortic valve replacement (TAVR). Treatment with a RAS inhibitor may reverse left ventricular remodeling and improve function. Objective: To investigate the association of prescription of a RAS inhibitor and outcomes after TAVR. Design, Setting, and Participants: Retrospective cohort study of TAVR procedures performed in the United States (using the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapies Registry) between July 2014 and January 2016 that were linked to Medicare claims data (final date of follow-up: March 31, 2017). To account for differences in demographics, echocardiographic findings, and in-hospital complications, 1:1 propensity matching was performed. Exposures: Initial hospital discharge prescription of a RAS inhibitor after TAVR. Main Outcomes and Measures: Primary outcomes were all-cause death and readmission due to heart failure at 1 year after discharge, which were considered separately. The secondary outcome was health status assessed by the Kansas City Cardiomyopathy Questionnaire (KCCQ; score range: 0-100, with a higher score indicating less symptom burden and better quality of life; a small effect size was defined as 5 points) at 1 year. Results: Among 21 312 patients who underwent TAVR at 417 US sites, 8468 patients (39.7%) were prescribed a RAS inhibitor at hospital discharge. After propensity matching, 15 896 patients were included (mean [SD] age, 82.4 [6.8] years; 48.1% were women; mean [SD] left ventricular ejection fraction [LVEF], 51.9% [11.5%]). Patients with a prescription for a RAS inhibitor vs those with no prescription had lower mortality rates at 1 year (12.5% vs 14.9%, respectively; absolute risk difference [ARD], -2.4% [95% CI, -3.5% to -1.4%]; hazard ratio [HR], 0.82 [95% CI, 0.76 to 0.90]) and lower heart failure readmission rates at 1 year (12.0% vs 13.8%; ARD, -1.8% [95% CI, -2.8% to -0.7%]; HR, 0.86 [95% CI, 0.79 to 0.95]). When stratified by LVEF, having a prescription for a RAS inhibitor vs no prescription was associated with lower 1-year mortality among patients with preserved LVEF (11.1% vs 13.9%, respectively; ARD, -2.81% [95% CI, -3.95% to -1.67%]; HR, 0.78 [95% CI, 0.71 to 0.86]), but not among those with reduced LVEF (18.8% vs 19.5%; ARD, -0.68% [95% CI, -3.52% to 2.20%]; HR, 0.95 [95% CI, 0.81 to 1.12]) (P = .04 for interaction). Of 15 896 matched patients, 4837 (30.4%) were included in the KCCQ score analysis and improvements at 1 year were greater in patients with a prescription for a RAS inhibitor vs those with no prescription (median, 33.3 [interquartile range, 14.2 to 51.0] vs 31.3 [interquartile range, 13.5 to 51.1], respectively; difference in improvement, 2.10 [95% CI, 0.10 to 4.06]; P < .001), but the effect size was not clinically meaningful. Conclusions and Relevance: Among patients who underwent TAVR, receiving a prescription for a RAS inhibitor at hospital discharge compared with no prescription was significantly associated with a lower risk of mortality and heart failure readmission. However, due to potential selection bias, this finding requires further investigation in randomized trials.

Asymptomatic Severe Aortic Valve Stenosis-When to Intervene: a Review of the Literature, Current Trials, and Guidelines.

PURPOSE OF REVIEW: The optimal treatment for asymptomatic patients with severe aortic valve stenosis (AS) is not clearly known. Here, we review the available data on the management of such patients. RECENT FINDINGS: Half of patients with severe AS are asymptomatic at the time of diagnosis, and are at risk for adverse events, including sudden cardiac death. A significant proportion of these patients develop AS-related symptoms within 1 or 2 years. Clinical and echocardiographic characteristics are predictors of poor outcomes and can guide treatment decisions. Several non-randomized studies and meta-analyses have suggested benefit from early AVR for asymptomatic severe AS, including improved all-cause, cardiovascular, and valve-related mortality. Based on the available information, current guidelines suggest aortic valve replacement in the presence of specific characteristic, including left ventricular dysfunction and very severe AS with significantly elevated gradients. Although the available data suggests early AVR improves the clinical outcomes of these patients, most patients in current practice are managed conservatively. Six randomized trials are ongoing to better elucidate the ideal management of asymptomatic severe AS patients.

Challenges in Aortic Valve Stenosis: Low-Flow States Diagnosis, Management, and a Review of the Current Literature.

PURPOSE OF REVIEW: We will describe and define the current diagnosis, management, and potential therapy for low-flow aortic stenosis (AS) states, as well as summarize the available evidence underlying these recommendations. RECENT FINDINGS: Low-flow aortic stenosis syndromes have worse prognoses than traditionally defined normal flow severe aortic stenosis. In this setting, aortic valve replacement is the only therapy that improves outcomes. Transcatheter aortic valve replacement has an ever-expanding role in the treatment of aortic stenosis, and there is growing evidence that TAVR may be a preferred therapy for low-flow AS states. Aortic stenosis remains one of the most common valvular diseases requiring therapy. Low-flow AS represents up to 40% of all patients with AS and is associated with significant mortality. This condition requires further testing for appropriate diagnosis and treatment. Low-flow AS states have poor prognoses, thus AVR and especially TAVR have a growing role in treatment of this challenging subset of AS patients.

Coronary Artery Anomalies: When You Need to Worry.

PURPOSE OF REVIEW: There is a broad spectrum of coronary artery anomalies that cardiologists may encounter either incidentally or during evaluation for cardiac symptoms. These anomalies include anomalous coronary arteries arising from the opposite sinus of Valsalva (ACAOS), coronary fistulae, and coronary artery aneurysms. This manuscript outlines the unique features, diagnostic characteristics, and treatment considerations for these lesions. RECENT FINDINGS: Intravenous ultrasound (IVUS), computed tomographic angiography (CTA), and magnetic resonance imaging (MRI) are becoming more sophisticated and will be increasingly used to facilitate the optimal treatment approach for coronary anomalies. There are a wide variety of coronary artery anomalies and their clinical ramifications range from benign to potentially fatal. Coronary anomalies often have complex anatomy and require advanced imaging modalities for comprehensive characterization. Due to the heterogeneity in lesion characteristics and outcomes, physicians should consider clinical and imaging features to create individualized management plans, along with referral to adult congenital heart disease centers.

Resolution of severe hemolysis and paravalvular aortic regurgitation employing an Amplatzer Vascular Plug 4: the importance of detailed pre-procedural planning using CT angiography.

A 76-year-old woman presented with progressive heart failure and transfusion-dependent hemolytic anemia due to severe paravalvular aortic regurgitation 4 years after bioprosthetic aortic valve replacement. She was deemed not to be a candidate for redo cardiac surgery due to a porcelain aorta and multiple comorbid medical conditions. We describe the role of pre-procedure contrast-enhanced, ECG-gated computed tomographic angiography to characterize the anatomy of the paravalvular leak connection for appropriate occluder device selection leading to successful percutaneous closure and resolution of the paravalvular regurgitation and hemolytic anemia.

Platypnea-Orthodeoxia Syndrome: To Shunt or Not to Shunt, That is the Question.

Platypnea-orthodeoxia syndrome is a rare disease defined by dyspnea and deoxygenation, induced by an upright position, and relieved by recumbency. Causes include shunting through a patent foramen ovale and pulmonary arteriovenous malformations. A 79-year-old woman experienced 2 syncopal episodes at rest and presented at another hospital. In the emergency department, she was hypoxic, needing 6 L/min of oxygen. Her chest radiograph showed nothing unusual. Transthoracic echocardiograms with saline microcavitation evaluation were mildly positive early after agitated-saline administration, suggesting intracardiac shunting. She was then transferred to our center. Right-sided heart catheterization revealed no oximetric evidence of intracardiac shunting while the patient was supine and had a low right atrial pressure. However, her oxygen saturation dropped to 78% when she sat up. Repeat transthoracic echocardiography while sitting revealed a dramatically positive early saline microcavitation-uptake into the left side of the heart. Transesophageal echocardiograms showed a patent foramen ovale, with right-to-left shunting highly dependent upon body position. The patient underwent successful percutaneous patent foramen ovale closure, and her oxygen supplementation was suspended. In patients with unexplained or transient hypoxemia in which a cardiac cause is suspected, it is important to evaluate shunting in both the recumbent and upright positions. In this syndrome, elevated right atrial pressure is not necessary for significant right-to-left shunting. Percutaneous closure, if feasible, is first-line therapy in these patients.

Comparison of aortic annulus size by transesophageal echocardiography and computed tomography angiography with direct surgical measurement.

This study sought to compare the accuracy of 2-dimensional transesophageal echocardiography (TEE) and computed tomography angiography (CTA) for noninvasive aortic annular sizing as required for transcatheter aortic valve implantation (TAVI). Direct intraoperative (OR) sizing is the gold standard for aortic annular measurement in surgical aortic valve replacement. Unlike surgical aortic valve replacement, TAVI requires noninvasive assessment of aortic annular dimensions for determining the size of prosthesis to be implanted and controversy exists regarding the best imaging technique for TAVI sizing. Preoperative CTA and OR TEE images of the aortic annulus in 227 patients who underwent proximal aortic surgery with OR annular sizing at the Duke University Medical Center were reviewed. Both imaging techniques were compared with direct OR measurements of aortic annulus diameter using metric sizers as the gold standard. CTA overestimated aortic annulus diameter in 72.2% of cases, with 46.3% >1 TAVI valve-size (>3 mm) overestimations, whereas TEE underestimated aortic annulus diameter in 51.1% of cases, with 16.7% >1 valve-size underestimations. Combining both techniques improved the estimation of aortic annular size. In conclusion, there are limitations to current imaging techniques for noninvasive determination of aortic annular dimensions compared with direct OR sizing. Undersizing by TEE and oversizing by CTA are common and may be related to differences in methods for sizing an elliptical structure. Combining measurements from both techniques would decrease the false exclusion rate for TAVI eligibility because of size mismatch.

Assessment of single-bolus contrast administration technique using hybrid dual-source ECG-gated thoracic and dual-source non-ECG-gated high-pitch abdominopelvic CT acquisitions for procedural planning before transcatheter aortic valve replacement.

PURPOSE: This study aimed to assess vascular contrast opacification and homogeneity using single-bolus contrast administration with hybrid thoracic and abdominopelvic computed tomographic angiography in patients with severe aortic valve stenosis. MATERIALS AND METHODS: Combination electrocardiogram-gated thoracic and dual-source, high-pitch abdominopelvic computed tomographic angiography examinations of 50 patients with severe aortic stenosis between December 2013 and March 2014 were reviewed. Contrast administration was individualized to patient-specific physiology. Image analysis of vascular opacification was obtained and interdependencies of vascular contrast and homogeneity of contrast distribution were assessed. RESULTS: The mean volume of contrast administered was 106 ± 11.7 mL. Mean attenuation was 371 ± 90.7 Hounsfield units (HU) in the thoracic aorta and 388 ± 95.9 HU in the abdominal aorta. Homogeneous opacification was obtained throughout with coefficient of variation of 11%. CONCLUSIONS: Procedural planning for transcatheter aortic valve replacement can be achieved using a single-injection bolus contrast protocol in combination with a 2-part multidetector computed tomographic image acquisition technique with optimal opacification of major arterial structures.