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.

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.

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.

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.

Thrombolytic therapy for thrombosis of continuous flow ventricular assist devices.

BACKGROUND: Despite chronic systemic anticoagulation, advanced heart failure patients treated with a continuous-flow left ventricular assist device (LVAD) remain at risk for pump thrombosis. Pump thrombosis may initially be suspected in the setting of clinical and biochemical evidence for intravascular hemolysis, putatively related to shear stress on red blood cells propelled through a partially occluded pump. Limited data exist to guide management in these patients. METHODS AND RESULTS: We present a series of 8 LVAD patients who presented with intravascular hemolysis secondary to pump thrombosis who were treated with intraventricular thrombolytic therapy. In 3 patients, thrombolytic therapy led to complete and lasting resolution of hemolysis, suggesting successful dissolution of pump thrombus. In the remaining 5 patients, thrombolytic therapy ultimately failed to halt or reverse pump thrombosis and hemolysis: 1 patient required emergent pump exchange, 2 patients progressed to cardiogenic shock and died, 1 patient suffered a debilitating stroke after which care was withdrawn, and 1 patient underwent cardiac transplantation. CONCLUSIONS: In the setting of LVAD thrombosis, thrombolytic therapy is an alternate treatment strategy in a subset of patients. Candidacy for this alternate procedure must carefully weigh the risks of complications, including hemorrhage and thromboembolism.

Treatment of mechanical aortic valve thrombosis with heparin and eptifibatide.

A 75-year old woman with a history of coronary disease status post 3-vessel coronary artery bypass grafting (CABG) 8 years ago and a repeat one-vessel CABG 2 years ago in the setting of aortic valve replacement with a #19 mm St. Jude bileaflet mechanical valve for severe aortic stenosis presented with two to three weeks of progressive dyspnea and increasing substernal chest discomfort. Echocardiography revealed a gradient to 31 mmHg across her aortic valve, increased from a baseline of 13 mmHg five months previously. Fluoroscopy revealed thrombosis of her mechanical aortic valve. She was not a candidate for surgery given her multiple comorbidities, and fibrinolysis was contraindicated given a recent subdural hematoma 1 year prior to presentation. She was treated with heparin and eptifibatide and subsequently demonstrated resolution of her aortic valve thrombosis. We report the first described successful use of eptifibatide in addition to unfractionated heparin for the management of subacute valve thrombosis in a patient at high risk for repeat surgery or fibrinolysis.

Invasive hemodynamic evaluation in patients with mechanical aortic valves.

Invasive hemodynamic evaluation in the patient with a mechanical aortic valve has in the past required transseptal or apical left ventricular puncture in order to obtain left ventricular pressure measurements. Over the last few years, several case reports have described the feasibility of using a coronary pressure-sensing guidewire to cross mechanical prosthetic aortic valves. In the current manuscript, we report four cases in which the use of a pressure-sensing guidewire was utilized for invasive hemodynamic diagnostic evaluation in patients with mechanical aortic valves. Furthermore, we present a detailed description of the technical approach to this technique and the limitations of this approach.

Transcatheter aortic valve replacement: an update.

Aortic stenosis affects many people worldwide with a significant impact on morbidity and mortality with uncorrected, symptomatic aortic valve stenosis carrying mortality of 50% at one year. Degenerative calcific pathology, the most common cause of aortic stenosis, increases in prevalence with age; estimated prevalence of 5% in individuals over 75 years of age. Despite the malignant prognosis without valve replacement, many patients are not offered surgery due to advanced age and co-existing medical conditions; reported to be a third of symptomatic patients. In the last several years, transcatheter aortic valve replacement has emerged as an alternative treatment in patients with high or prohibitive open surgical risk. The PARTNER cohort B data, employing the Sapien valve, demonstrated a 20% absolute mortality benefit at one year compared with medical therapy. In this review, we provide an update of this technology and discuss patient selection, procedural planning, complications, and look toward the future of transcatheter heart valves in the treatment of aortic stenosis.

Infective endocarditis: a comprehensive overview.

Infective endocarditis (IE) is an infection of a heart valve or other cardiac structure at a site of endothelial damage. The definition has been also expanded to include infected cardiac devices. A variety of organ systems may be adversely affected in patients with IE. Although advances have improved the diagnostic accuracy for IE, morbidity and mortality remain remarkably high. This article reviews the pathophysiology, complications, diagnosis, and management of IE with recent updates to the literature and the major cardiovascular society guidelines. The increasingly prevalent clinical problem of intracardiac device-related IE is addressed, along with the recent changes to the IE prophylaxis guidelines.

Management of patients with bicuspid aortic valve disease.

OPINION STATEMENT: Our approach to the management of the patient with a bicuspid aortic valve (BAV) takes several factors into consideration. First, is the dysfunction of the valve due to aortic stenosis (AS), aortic regurgitation (AR), or a combination of stenosis and regurgitation, and what is the severity? Next, is there aortic dilation in any of the regions (sinuses of Valsalva, sinotubular junction, tubular ascending aorta, or transverse arch) discussed in this article. In general, we follow patients with a BAV and moderate valve dysfunction (AS or AR) with yearly surveillance transthoracic echocardiography for left ventricular function, jet velocity, gradient, and valve area with AS, whereas left ventricular (LV) function and LV dimensions are monitored for patients with AR. In addition, yearly clinical evaluation for change in symptom status or functional capacity is critical. More recently, we have utilized NT-pro BNP levels to help assess patients, particularly those in whom the anatomic severity does not match the clinical symptoms (ie, the valve severity appears mild but the patient is complaining of symptoms or the valve severity seems significant but no symptoms are noted). All patients with a bicuspid valve should have evaluation of the aorta with a MRI or CT angiography at some point, as 50% of BAV patients have aortic root involvement. At our institution, cardiac MRI is preferred unless there is a contraindication, particularly in younger patients, given the cumulative radiation exposure from surveillance CT scans. Cardiac MRI also provides the added benefit of information regarding LV function, LV dimensions, and assessment of valve stenosis/regurgitation severity, thus obviating the need for echocardiographic data in those being followed with serial cardiac MRI. For those with no aortic dilatation, we tend to use only echocardiography for follow-up. For patients with mild aortic dilation, surveillance aortic imaging is usually performed every 3-5 years. However, for those with greater degrees of aortic dilation (aortic diameters >4.0 cm) or notable interval change in dimensions, then aortic imaging every year is conducted. For young adult patients with isolated aortic stenosis, balloon aortic valvuloplasty is often an effective and temporizing treatment option. In older patients with aortic stenosis or those with AR, aortic valve replacement, with or without a surgery on the aorta depending on whether concomitant dilation (aortic diameter >4.5 cm) of the aorta is present, is the preferred management strategy. In a few patients, surgery on the aortic alone may be indicated if the maximal diameter exceeds 5.0 cm.

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.

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).

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.