Serge Harb

Radiofrequency ablation of atrial fibrillation in patients with mechanical mitral valve prostheses safety, feasibility, electrophysiologic findings, and outcomes.

OBJECTIVES The purpose of this study was to evaluate the feasibility, safety, and outcomes of radiofrequency ablation of atrial fibrillation (AF) in patients with mechanical mitral valve replacement (MVR). BACKGROUND The role of ablative therapy in patients with MVR is not yet established, with safety concerns and very few outcome data. METHODS Between January 2003 and December 2008, we followed up 81 patients with MVR undergoing first-time AF ablation (compared with 162 age- and sex-matched controls). Arrhythmia recurrences were identified by symptoms with documentation, event monitoring, Holter monitoring, and electrocardiograms. RESULTS All MVR and control patients underwent ablation under therapeutic international normalized ratio. No entrapment of catheters or stroke occurred. There were no differences in terms of procedure-related complications between the groups (p = NS). Patients with MVR had larger atria (p < 0.0001), lower left ventricular ejection fractions (p = 0.0001), and more concomitant atrial flutter at baseline (p < 0.0001). Over a 24-month follow-up, they had higher recurrence rates compared with controls (49.4% vs. 27.7% after a single ablation, p = 0.0006). The creation of flutter lines significantly reduced recurrences in patients with any history of atrial flutter (16.7% vs. 60.9%, p = 0.009). At last follow-up, 82.7% of MVR patients had their arrhythmia controlled (69.1% not receiving antiarrhythmic drugs). CONCLUSIONS Radiofrequency ablation is feasible and safe for patients with MVR. It allowed restoration of sinus rhythm in a substantial proportion of patients undergoing ablation. An abnormal atrial substrate underlies recurrences in these patients. The ablation procedure needs to be further refined with a focus on extra pulmonary vein triggers and concomitant flutters to improve outcomes.

Implantable Cardioverter-Defibrillators in Patients with CKD: A Propensity-Matched Mortality Analysis

BACKGROUND AND OBJECTIVES Benefits of transvenous implantable cardioverter-defibrillators (ICDs) in prevention of sudden cardiac death among the general population are proven. However, the benefit of ICDs remains unclear in CKD. A propensity-matched analysis was conducted to examine the survival benefits of ICDs placed for primary prevention in those with CKD not on dialysis (eGFR<60 ml/min per 1.73 m(2)). DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS The Cleveland Clinic CKD registry was utilized to identify individuals who had an echocardiogram at the institution (between 2001 and October 2011). A propensity score of the likelihood of receiving an ICD was developed with the following variables: demographics, comorbid conditions, use of cardioprotective medications, eGFR, left ventricular ejection fraction, and ventricular arrhythmia. One-to-one greedy matching was used with 0.1 caliper width to match patients with and without an ICD. A Cox proportional hazards model was used to examine survival of matched patients with and without an ICD. RESULTS This study included 1053 ICD patients and 9435 potential controls. Of 1053 ICD patients (60%), 631 were matched to the control group. During a median follow-up of 2.9 years (25th and 75th percentiles, 1.5, 4.7), 578 patients died. After adjusting for covariates, the hazard of mortality among propensity-matched patients was 0.69 (95% confidence interval [95% CI], 0.59 to 0.82) for the ICD group compared with the non-ICD group. A significant interaction was found between ICDs and eGFR (P=0.04). Presence of an ICD was associated with a lower risk of death among those with eGFRs of 45-59 ml/min per 1.73 m(2) (hazard ratio [HR], 0.58; 95% CI, 0.44 to 0.77) and 30-44 ml/min per 1.73 m(2) (HR, 0.65; 95% CI, 0.50 to 0.85), but not among those with eGFRs<30 ml/min per 1.73 m(2) (HR, 0.98; 95% CI, 0.71 to 1.35). CONCLUSIONS Transvenous ICDs placed for primary prevention are associated with a survival benefit in those with stage 3 CKD, but not in those with stage 4 CKD.

First-in-Human Implantations of the NaviGate Bioprosthesis in a Severely Dilated Tricuspid Annulus and in a Failed Tricuspid Annuloplasty Ring

Based on an old misconception that the tricuspid valve is not important for cardiac performance, functional tricuspid regurgitation (TR) has been historically ignored. As a consequence, an increasing number of patients present in the current era with severe TR associated with right heart failure that is refractory to medical treatment. Traditional or redotricuspid valve surgery in that setting has been shown to have high mortality (up to 35% at 30 days).1–3 Thereby, transcatheter valve implantation technology seems as an attractive alternative. Herein, we report the first-in-human successful implantation of the NaviGate valved-stent (NaviGate Cardiac Structures, Inc, NCSI, Lake Forest, CA) in 2 patients with severe TR and prohibitive risk for conventional surgery, for which they received Food and Drug Administration and institutional review board approvals for compassionate use (Figure 1). Figure 1. The NaviGate valved-stent. A , Ventricular view. B , Lateral view. A 64-year-old woman presented after multiple admissions for refractory right heart failure with severe functional TR secondary to annular dilatation, severe right ventricular (RV) dysfunction, severe pulmonary hypertension (systolic pressure, 75 mm Hg), and moderate ischemic mitral regurgitation (Figure 2A). Other comorbidities included chronic kidney dysfunction, chest radiation for breast cancer, atrial fibrillation, obstructive lung disease, and coronary bypass surgery with patent grafts. The patient was deemed high risk for conventional open-heart surgery by the Multidisciplinary Heart Team and was found a candidate for compassionate use of a first-in-human NaviGate valved-stent implantation. Preoperative sizing included a focused 4-dimensional computed tomography that was used to develop a 3-dimensional printing model of the …

Prognostic value of stress imaging after revascularization: a systematic review of stress echocardiography and stress nuclear imaging

BACKGROUND Risk assessment may be important in patients being considered for repeat revascularization after prior coronary intervention or surgery. We sought the prognostic value of radionuclide stress myocardial perfusion imaging or echocardiography among patients with previous revascularization. METHODS Studies on the outcomes of stress imaging tests after revascularization were selected from an electronic search if they reported the odds or hazard ratio (HR) of an abnormal stress test in the prediction of mortality (cardiac or total), hard cardiac events (cardiac death and myocardial infarction [MI]), total hard events (total mortality and MI]), or overall events (cardiac death, MI, and repeat revascularization). RESULTS In 29 studies (12,874 patients, 63 ± 3 years, 80% men), an abnormal test result was associated with hard cardiac events (HR 1.2, 95% CI 1.1-1.3), cardiac mortality (HR 5.8, 95% CI 0.8-10.8), total mortality (HR 2.2, 95% CI 1.3-3.1), total hard events(HR 2.4, 95% CI 1.4-3.3), and overall events (HR 1.2, 95% CI 1.1-1.3). The nature of the end point was not associated with differences in the prediction of events, but the type of revascularization showed a significant association with outcome, with percutaneous intervention portending a worse outcome. Age and the timing of the stress imaging postrevascularization were inversely associated with survival. Gender, length of follow-up after testing, symptom status, past infarction, and risk factor status did not explain interstudy heterogeneity. CONCLUSIONS In patients with previous revascularization, abnormal results at stress echocardiography or radionuclide myocardial perfusion imaging are predictive of subsequent events, with age, type of revascularization, and the timing of the stress imaging after revascularization being important sources of heterogeneity between studies.

New Insights into Pericarditis: Mechanisms of Injury and Therapeutic Targets

Purpose of ReviewThis review article aims to provide a contemporary insight into the pathophysiological mechanisms of and therapeutic targets for pericarditis, drawing distinction between autoinflammatory and autoimmune pericarditis.Recent FindingsRecent research has focused on the distinction between autoinflammatory and autoimmune pericarditis. In autoinflammatory pericarditis, viruses can activate the sensor molecule of the inflammasome, which results in downstream release of cytokines, such as interleukin-1, that recruit neutrophils and macrophages to the site of injury. Conversely, in autoimmune pericarditis, a type I interferon signature predominates, and pericardial manifestations coincide with the severity of the underlying systemic autoimmune disease. In addition, autoimmune pericarditis can also develop after cardiac injury syndromes. With either type of pericarditis, imaging can help stage the inflammatory state. Prominent pericardial delayed hyperenhancement on magnetic resonance imaging suggests ongoing inflammation whereas calcium on computed tomography suggests a completed inflammatory cascade. In patients with ongoing pericarditis, treatments that converge on the inflammasome, such as colchicine and anakinra, have proved effective in recurrent autoinflammatory pericarditis, though further clinical trials with anakinra are warranted.SummaryAn improved understanding of the pathophysiological mechanisms of pericarditis helps unravel effective therapeutic targets for this condition.

Mitral Valve Disease: a Comprehensive Review

Purpose of ReviewThis review aims to provide a comprehensive assessment of mitral valve disease, both mitral stenosis and mitral regurgitation, starting with an overview of the valve anatomy.Recent FindingsThe advent of three-dimensional imaging has allowed a better representation of the valve anatomy. Rheumatic disease is still the number one cause of mitral stenosis worldwide and percutaneous balloon mitral valvuloplasty remains the therapy of choice when indicated and in anatomically eligible patients. Mitral regurgitation (MR) is classified as primary (i.e., lesion in the mitral apparatus) or secondary (caused by left ventricular geometrical alterations). While surgery, preferably repair, is still the recommended therapy for severe primary MR, percutaneous approaches to repair and/or replace the mitral valve are being extensively investigated.SummaryMitral valve disease is common. A careful understanding of mitral valve anatomy and the disease processes that affect the valve are crucial for providing optimal patient care.

National patterns in imaging utilization for diagnosis of cardiac amyloidosis: A focus on Tc99m-pyrophosphate scintigraphy

AbstractBackground Tc99m-pyrophosphate (Tc99m-PYP) scintigraphy has emerged as a diagnostic modality for transthyretin (TTR) cardiac amyloidosis (CA). We sought to examine the variability in test utilization across multiple centers in the US.MethodsAn electronic, web-based survey addressing specifics on Tc-99m PYP imaging was emailed to ASNC members, totaling 2785 recipients. Only one response per institution was allowed.Results Responses were collected from 101 centers between July 2 and July 27, 2015. Among the respondents, 24% performed Tc-99m PYP specifically for CA diagnosis. The most commonly used dose was 20 mCi (37%) and most centers (35%) imaged 1 hour after injection. Scans were most often interpreted by cardiologists (60%). Quantification of uptake was performed in 57% of institutions with almost half (43%) utilizing the heart-to-contralateral lung (H/CL) ratio.ConclusionsThis national survey shows relatively low penetrance and high variability in Tc99m-PYP scintigraphy for CA diagnosis highlighting the need for standardization.

Left Atrial Appendage Occlusion/Exclusion: Procedural Image Guidance with Transesophageal Echocardiography

&NA; Atrial fibrillation is the most common arrhythmia worldwide and is a major risk factor for embolic stroke. In this article, the authors describe the crucial role of two‐ and three‐dimensional transesophageal echocardiography in the pre‐ and postprocedural assessment and intraprocedural guidance of percutaneous left atrial appendage (LAA) occlusion procedures. Although recent advances have been made in the field of systemic anticoagulation with the novel oral anticoagulants, these medications come with a significant risk for bleeding and are contraindicated in many patients. Because thromboembolism in atrial fibrillation typically arises from thrombi originating in the LAA, surgical and percutaneous LAA exclusion/occlusion techniques have been devised as alternatives to systemic anticoagulation. Currently, surgical LAA exclusion is typically performed as an adjunct to other cardiac surgical procedures, which limits the number of eligible patients. Recently, several percutaneously delivered devices for LAA exclusion from the systemic circulation have been developed, some of which have been shown in clinical trials to reduce the risk for thromboembolism. These devices use an either purely endocardial LAA occlusion approach, such as the Watchman and Amulet procedures, or both an endocardial and a pericardial (epicardial) approach, such as the Lariat procedure. In the Watchman and Amulet procedures, a transseptally delivered structure composed of nitinol is placed in the LAA orifice, thereby excluding the LAA from the systemic circulation. In the Lariat procedure, a magnet link is created between a transseptally delivered endocardial wire and epicardially delivered pericardial wire, followed by epicardial suture ligation of the LAA. HighlightsThe LAA is the most common site of thrombus formation in nonvalvular atrial fibrillation.In nonvalvular atrial fibrillation, percutaneous LAA occlusion/exclusion is an alternative method of thromboembolism prevention for patients who are either ineligible for or too high risk to receive systemic anticoagulation therapy.2D/3D transesophageal echocardiography has a critical role in all percutaneous LAA occlusion/exclusion procedures, including screening for eligibility, device sizing, intraprocedural guidance, and postprocedural follow up.The most commonly used percutaneous LAA occlusion/exclusion devices worldwide include the Watchman, Amulet, and Lariat.

Mean Right Atrial Pressure for Estimation of Left Ventricular Filling Pressure in Patients with Normal Left Ventricular Ejection Fraction: Invasive and Noninvasive Validation

Background: There is a paucity of data on the utility of right atrial pressure (RAP) for estimating pulmonary capillary wedge pressure (PCWP) in patients with normal ejection fraction (EF), including patients with heart failure with preserved EF. Methods: Mean RAP was compared with PCWP in 129 patients (mean age, 61 ± 11 years; 45% men) with exertional dyspnea enrolled in a multicenter study. Measurements included left ventricular volumes, EF, and mitral inflow velocities. Results: Mean PCWP was 14 ± 7 mm Hg, and mean RAP was 8 ± 5 mm Hg. A significant relation was present between mean RAP and mean PCWP (r2 = 0.5, P < .001). RAP > 8 mm Hg had 76% sensitivity and 86% specificity in detecting mean PCWP > 12 mm Hg. In 101 patients with inconclusive mitral filling pattern (defined according to American Society of Echocardiography/European Association of Cardiovascular Imaging 2016 diastolic function recommendations), RAP by catheterization had sensitivity of 73% and specificity of 91%. In a subset of 59 patients with echocardiographic assessment of mean RAP, RAP by echocardiography had sensitivity of 76% and specificity of 89%. Conclusions: Mean RAP provides useful information about mean PCWP in many patients with normal left ventricular EF. There is good sensitivity and excellent specificity when combining invasive or noninvasive RAP and mitral velocities to determine if PCWP is elevated. HighlightsMean RAP provides useful information about mean PCWP in patients with normal LV EF.RAP may be used to draw conclusions about PCWP if one of three variables is missing.RAP may be an inaccurate measure of PCWP with predominant RV disease, severe TR, or MR.

Pitfalls and Pearls for 3-Dimensional Printing of the Tricuspid Valve in the Procedural Planning of Percutaneous Transcatheter Therapies

There is a recent rise in percutaneous therapies for the tricuspid valve. Due to the innovative nature of these procedures and the complex anatomy of the tricuspid valve, procedural planning often relies on 3-dimensional (3D) printing. Whereas contrast-enhanced 4-dimensional (4D) computed tomography