Effect of mitral valve transcatheter edge-to-edge repair on indices of left atrial performance in chronic mitral regurgitation.

INTRODUCTION: Effect of transcatheter edge-to-edge repair (TEER) using MitraClip in patients with mitral regurgitation (MR) on left atrial (LA) kinetic energy (LAKE), an index of LA work, and LA strain, a measure of LA performance, have not been well defined. METHODS: Patients with chronic primary or secondary 3+ or 4+ MR were analyzed pre- and post-TEER using MitraClip. LAKE was determined by echocardiography using LA stroke volume and A-wave velocity. Peak atrial longitudinal strain (PALS), peak atrial strain in early diastole, and peak atrial contraction strain (PACS) were obtained by speckle tracking echocardiography. RESULTS: Thirty-nine patients undergoing TEER with MitraClip were screened, 12 met criteria for analysis (9 primary and 3 secondary MR). Compared to pre-TEER, there was a significant increase post-TEER in LAKE (71.0 ± 64.1 vs. 177.5 ± 167.9 dyne·cm·103 , respectively; p = .008) and Doppler transmitral A-wave velocity (87.8 ± 41.4 vs. 138.5 ± 43.7 cm/s, respectively; p < .001); LA stroke volume did not change significantly. Mitral valve mean gradient significantly increased post-TEER compared to pre-TEER (5.7 ± 2.1 vs. 3.3 ± 2.1 mmHg, respectively; p = .01). There was a trend toward decrease in PALS post-TEER compared to pre-TEER (16.2 ± 4.8 vs. 20.7 ± 9.9%, respectively; p = .05). Peak atrial strain in early diastole significantly decreased post-TEER compared to pre-TEER (7.2 ± 3.0 vs. 14.1 ± 7.2%; respectively, p < .001), while PACS did not significantly change (9.1 ± 3.5 vs. 6.7 ± 5.2%, respectively; p = .07). CONCLUSION: In patients with chronic MR, LAKE increases after TEER with MitraClip driven by an increase in LA emptying velocities. Changes were also seen in LA strain with MitraClip. These procedurally induced changes due to mild mitral stenosis may have clinical implications.

Natural history of nonbacterial thrombotic endocarditis treated with warfarin.

We report on the natural history of a cohort of patients presenting with transient ischemic attack or stroke and nonbacterial thrombotic endocarditis treated with warfarin.Patients with valvular vegetations on echocardiography, stroke, or transient ischemic attack presenting to a single neurologist were included. All patients were treated with warfarin until the vegetation resolved or for two years, then were switched to aspirin and had at least one clinical and echocardiographic follow-up.Twenty-nine patients were included and followed for a median of 27 months. Average age was 42 years and 72% were female. Two patients had vegetations on two valves. Five patients (17%) had recurrent strokes, three had systemic lupus erythematosus and antiphospholipid antibodies, one had antiphospholipid antibodies alone and one had neither condition. Three of the five patients did not have resolution of the vegetation at the time of the event. The valvular vegetations resolved in 23 of the 31 affected valves (74%) after a median of 11 months (range 4.5-157.5). Eleven patients had at least one follow-up echocardiogram after resolution of the vegetation and none had recurrent vegetations after warfarin was stopped.This study should serve to provide general recommendations regarding treatment of patients with TIA/stroke with nonbacterial thrombotic endocarditis. Valvular vegetations resolve in most patients and the risk of recurrent stroke is low. Warfarin can safely be switched to aspirin in most patients when the vegetation resolves or after two years if it does not resolve. Prolonged warfarin may be warranted in patients with systemic lupus erythematosus, positive antiphospholipid antibodies, and a persistent vegetation.

The Use of MitraClip in Secondary Mitral Regurgitation and Heart Failure.

Secondary (also known as functional) mitral regurgitation (MR) has increased substantially over the last several decades due to an increase in the prevalence of dilated cardiomyopathy (ischemic and non-ischemic). Mortality and morbidity in patients with dilated cardiomyopathy is much greater when associated with MR as compared to without MR. MR will result in further left ventricular (LV) volume overload, LV dilation, and pupillary muscle displacement resulting in deterioration of the severity of MR leading to a vicious cycle. Optimization of heart failure medical therapy, and cardiac resynchronization therapy for those that qualify, can improve severity of MR; however, significant MR will persist in certain patients. Transcatheter mitral valve repair to treat significant MR using the MitraClip (Abbott, Menlo Park, California), which grasps and coapts the posterior and anterior mitral valve leaflets, in appropriately selected patients with dilated cardiomyopathy and secondary MR has been shown to improve quality of life and prolong survival.

Impact of Stroke Volume Index and Left Ventricular Ejection Fraction on Mortality After Aortic Valve Replacement.

OBJECTIVE: To assess the impact of stroke volume index (SVI) and left ventricular ejection fraction (LVEF) on prognosis in patients with severe aortic stenosis, comparing those undergoing transcatheter aortic valve replacement (TAVR) and those with surgical AVR (SAVR). PATIENTS AND METHODS: A total of 742 patients from the CoreValve US Pivotal High-Risk Trial randomized to TAVR (n=389) or SAVR (n=353) from February 2011 to September 2012 were stratified by an SVI of 35 mL/m2 and LVEF of 50% for comparing all-cause mortality at 1 year. RESULTS: The prevalence of an SVI of less than 35 mL/m2 in patients who underwent TAVR and SAVR was 35.8% (125 of 349) and 31.3% (96 of 307), respectively; LVEF of less than 50% was present in 18.1% (63 of 348) and 19.6% (60 of 306), respectively. Among patients with an SVI of less than 35 mL/m2, 1-year mortality was similar between patients with TAVR and SAVR (16.3% vs 22.2%; P=.25). However, in those with an SVI of 35 mL/m2 or greater, 1-year mortality was lower in those with TAVR than SAVR (10.3% vs 17.3%; P=.03). In patients with an LVEF of less than 50%, mortality was not affected by AVR approach (P>.05). In patients with an LVEF of 50% or higher, TAVR was associated with lower mortality than SAVR when SVI was preserved (9.8% vs 18.6%; P=.01). Mortality was not affected by SVI within the same AVR approach when LVEF was 50% or higher. CONCLUSION: In patients with severe aortic stenosis at high risk, there is a significant interaction between AVR approach and the status of SVI and LVEF. When LVEF or SVI was reduced, prognosis was similar regardless of AVR approach. In those with preserved LVEF or SVI, TAVR was associated with a better prognosis than SAVR. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01240902.

Imaging Device Therapy: Essentials for the Imager.

Treatment of patients with heart failure with reduced ejection fraction has evolved. Recently, a fully implantable remote hemodynamic monitoring sensor in the pulmonary artery was approved in the treatment of patients at risk of heart failure readmissions. Several novel devices designed to offload the left atrium by creating a small interatrial shunt are being investigated. Cardiac imaging plays a vital role in the selection process, implantation, and monitoring of individuals with such devices. This article discusses in detail various imaging techniques and key clinical points relating to several cardiac devices used in the treatment of patients with heart failure.

Aortic Dysfunction in Mitral Regurgitation Due to Floppy Mitral Valve/Mitral Valve Prolapse.

BACKGROUND: Floppy mitral valve/mitral valve prolapse (FMV/MVP), a heritable disorder of connective tissue, often leads to mitral regurgitation (MR) and is the most common cause for mitral valve surgery in developed countries. Connective tissue disorders may affect aortic function, and a stiff aorta may increase the severity of MR. Aortic function, however, has not been studied in FMV/MVP with MR. METHODS: A total of 17 patients (11 men, 6 women) with FMV/MVP and significant MR were compared with 20 controls matched for age and gender. Aortic diameters (AoD) were measured from left ventriculograms at 2 and 4 cm above the aortic valve. Aortic pressures were measured directly using fluid-filled catheters. Aortic distensibility was calculated using the formula: 2(systolic AoD-diastolic AoD)/(diastolic AoD x pulse pressure). RESULTS: Aortic distensibility was significantly lower in FMV/MVP compared with control at 2 cm above the aortic valve (1.00 ± 0.19 versus 3.78 ± 1.10 10-3 mm Hg-1, respectively; p = 0.027) and 4 cm above the aortic valve (0.89 ± 0.16 versus 3.22 ± 0.19 10-3 mm Hg-1, respectively; p = 0.007). FMV/MVP patients had greater left ventricular (LV) end-systolic (88 ± 72 mL versus 35 ± 15 mL, p = 0.002) and end-diastolic (165 ± 89 mL versus 100 ± 41 mL, p = 0.005) volumes, and lower LV ejection fraction, compared with control (50 ± 12% versus 57 ± 6%, p = 0.034). CONCLUSION: Aortic distensibility is decreased (consistent with a stiff aorta) in patients with FMV/MVP and MR. A stiff aorta may increase the severity of MR. Thus, abnormal aortic function, which also deteriorates with age, may play an important role in the natural history of MR due to FMV/MVP.

Usefulness of Integrating Heart Failure Risk Factors Into Impairment of Global Longitudinal Strain to Predict Anthracycline-Related Cardiac Dysfunction.

The prediction of cancer therapeutics-related cardiac dysfunction (CTRCD) is an essential aspect of care for individuals who receive potentially cardiotoxic oncologic treatments. Certain clinical risk factors have been described for incident CTRCD, and measurement of left ventricular (LV) longitudinal strain by speckle tracking 2-dimensional echocardiography (2DE) is the best-validated myocardial mechanical imaging assessment to detect subtle changes in LV function during cancer treatment. However, the direct integration of clinical and imaging risk factors to predict CTRCD has not yet been extensively examined. This was a retrospective study of 183 women with breast cancer aged 50.9 ± 10.8 years who received treatment with anthracyclines (doxorubicin dose of 422 ± 69 mg/m2, with 41.2% of subjects also receiving trastuzumab) and underwent 2DE at clinically determined intervals. CTRCD was diagnosed when LV ejection fraction dropped ≥10% to a subnormal (<53%) value by 2DE. Left ventricular global longitudinal strain (LV-GLS) was assessed offline. The risk prediction tool based only on clinical factors previously described by Ezaz et al was applied to our cohort and accurately stratified these subjects into low-, intermediate-, and high-risk groups, with incident CTRCD in 7.4%, 26.9%, and 54.6%, respectively (chi-square = 20.7, p <0.0001). We developed novel multivariate models to predict CTRCD using (1) demographic variables only (c = 0.8674), (2) echocardiographic (peak LV-GLS) variables only (c = 0.8440), or (3) a combination of demographic and echocardiographic variables, with the combined model exhibiting superior receiver-operating characteristics (c = 0.9629). In conclusion, estimation of CTRCD risk should integrate all available data, including both clinical variables and an imaging assessment.

Radiation exposure of cardiac sonographers working in an academic noninvasive cardiovascular imaging laboratory.

BACKGROUND AND AIM: Exposure to workplace radiation among cardiac sonographers has been felt to be low, and patient-related sources have been considered negligible. Sonographers may be exposed to radiation from patient emitted sources as well as external sources in interventional laboratories. This study quantified radiation exposure to cardiac sonographers. METHODS: Cardiac sonographers, vascular imaging technologists, exercise physiologists, noninvasive nursing staff, and CT/MRI technologists were provided body dosimeter badges. Sonographers were provided dosimeter rings for their scanning hands. Radiation exposure was quantified from the dosimeter data, reported in millirems (mrem) for deep, eye, and shallow exposure, as well as shallow exposure data from the rings. Data were prospectively collected for 63 employees over a 12-month period and retrospectively analyzed. RESULTS: The mean annual deep body exposure in sonographers was 8.2 mrem/year, shallow exposure 9.8 mrem/year, eye exposure 8.5 mrem/year, and ring exposure 207 mrem/year. There was a significant difference between body and ring exposure (P = .0002). When comparing exposure data between the vascular imaging technologists, CT/MRI technologists, noninvasive nursing staff, and the cardiac sonographers, there were no statistical differences (P > .23). Exercise physiologists had significantly higher exposure compared to sonographers (P < .03). CONCLUSION: This single-center experience demonstrates that, while exposure is low, cardiac sonographers are exposed to workplace radiation, most likely from patient emitted radiation. The finding that radiation exposure from rings exceeded body exposure supports this conclusion. Continued education and assessment of work flow practices should be employed to minimize staff radiation exposure.

Self-Expanding Transcatheter Aortic Valve Replacement Versus Surgical Valve Replacement in Patients at High Risk for Surgery: A Study of Echocardiographic Change and Risk Prediction.

BACKGROUND: The CoreValve US High-Risk Clinical Study compared clinical outcomes and serial echocardiographic findings in patients with severe aortic valve stenosis after transcatheter aortic valve replacement (TAVR) with a self-expanding bioprosthesis or surgical aortic valve replacement (SAVR). METHODS AND RESULTS: Eligible patients were randomly assigned 1:1 to TAVR with a self-expanding bioprosthesis or SAVR (N=747). Echocardiograms were obtained at baseline, discharge, 30 days, 6 months, and 1 year after the procedure and were analyzed at a central core laboratory. Compared with SAVR patients (N=357), TAVR patients (N=390) had a lower mean aortic valve gradient, larger valve area, and less patient-prosthesis mismatch (all P<0.001), but more paravalvular regurgitation at discharge, which decreased at 1 year. SAVR patients experienced significant right ventricular systolic dysfunction at discharge and 1 month with normal right ventricular function at 1 year. One-year all-cause mortality was 14.2% for TAVR and 19.1% for SAVR patients. Preimplantation aortic regurgitation ≥mild was associated with reduced mortality hazard for both the TAVR (hazard ratio 0.48, 95% confidence interval 0.27-0.85; P=0.01) and the SAVR groups (hazard ratio 0.53, 95% confidence interval 0.32-0.87; P=0.01). Aortic regurgitation ≥mild after TAVR was associated with increased risk for all-cause mortality (hazard ratio 1.95, 95% confidence interval 1.08-3.53; P=0.03). CONCLUSIONS: In patients with severe aortic stenosis at increased surgical risk, TAVR was associated with better systolic valve performance, similar left ventricular remodeling, more paravalvular regurgitation, and less right ventricular systolic dysfunction compared with SAVR. Despite an overall mortality reduction for the TAVR group, ≥mild aortic valve regurgitation after TAVR was associated with an increased mortality hazard. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01240902.

The diagnosis and treatment of a mycotic coronary artery aneurysm: a case report.

Aneurysms of the coronary arteries are rare and are usually associated with atherosclerosis in adults. Mycotic coronary artery aneurysms are exceedingly uncommon and are typically associated with systemic bacteremia, endocarditis, or septic emboli. Literature and data describing the management of mycotic coronary artery aneurysms are limited. This case describes the successful diagnosis of a large right coronary artery aneurysm by transesophageal echocardiogram as well as the successful management of the aneurysm.

The role of repeat transesophageal echocardiography in patients without atrial thrombus prior to cardioversion or ablation.

BACKGROUND: Cardioversion (CV) and radiofrequency catheter ablation (RFA) are often used to restore sinus rhythm in patients with atrial fibrillation (AF). These procedures are associated with a risk for stroke. The use of transesophageal echocardiography (TEE) to guide the management of AF is a validated strategy for patients in whom CV is planned, as well patients before RFA. For patients in whom the initial procedure fails, repeat TEE is often performed before repeat CV or RFA. The aim of this study was to test the hypothesis that patients with initial negative results on TEE would be unlikely to have thrombi detected on subsequent TEE and thus may avoid repeat procedures. METHODS: A total of 2,999 patients with AF were identified via retrospective review who had undergone TEE before CV or RFA, and 418 of these individuals underwent repeat TEE. After excluding patients who underwent repeat TEE >365 days from the initial study (n = 135) and those with thrombi on initial TEE (n = 20), 263 patients who had underwent two or more examinations were identified and analyzed. RESULTS: Of 263 eligible patients, two (0.8%; 95% confidence interval, 0.21-2.7%) had thrombi on subsequent TEE. CONCLUSIONS: Fewer than 1% of patients with AF with negative results on baseline TEE had thrombi detected on repeat TEE before subsequent CV or RFA. Thus, it may be possible to selectively screen patients to identify those at low risk for developing thrombi subsequent to negative results on initial TEE, especially if patients are in sinus rhythm. These results suggest the need for a prospective trial to definitively answer the question regarding repeat TEE in low-risk patients.

Aortic valve thrombosis after implantation of temporary left ventricular assist device.

The use of assist devices for ventricular support after myocardial infarction with cardiogenic shock has become common practice. Thrombosis, bleeding, and infection are common complications. However, native valve thrombosis is a rare complication. We present a case of aortic valve thrombosis after implantation of a left ventricular assist device (LVAD) treated with thrombus removal at time of device exchange.

Effect of cardiac resynchronization therapy on myocardial gene expression in patients with nonischemic dilated cardiomyopathy.

BACKGROUND: Cardiac resynchronization therapy (CRT) improves echocardiographic measures of ventricular structure and function in the failing heart. To determine whether or not these changes are representative of true biologic reverse ventricular remodeling or simply an artifact of an improved contraction pattern, we evaluated changes in myocardial gene expression typical of reverse remodeling before and after chronic CRT. METHODS AND RESULTS: Optimally medically treated patients with nonischemic heart failure meeting standard clinical criteria for CRT were enrolled. Before implantation of a CRT device, baseline echocardiogram and endomyocardial biopsies were obtained. These studies were repeated after 6 months of CRT. Using quantitative reverse-transcriptase polymerase chain reaction, the amount of messenger RNA for selected genes regulating contractile function (sarcoplasmic reticulum Ca2+ ATPase, alpha- and beta-myosin heavy chain [MHC] isoforms, phospholamban [PLB]), and pathologic hypertrophy (beta-MHC and atrial natriuretic peptide [ANP]) was determined from biopsy samples. Changes in gene expression (baseline to 6 months) were determined and correlated to changes in echocardiographic remodeling parameters. Ten patients were enrolled in the study, with 7 completing both baseline and follow-up biopsies and echocardiograms. On average, a significant increase was observed in alpha-MHC and PLB gene expression from baseline to 6 months (P = .016 for both). Beta-MHC levels tended to decrease with CRT (P = .078). Increased alpha-MHC levels correlated best with decreases in left ventricular end-diastolic dimension (P = .073, r = -0.71) and reductions in mitral regurgitation. No significant correlation between ejection fraction and gene expression was found. CONCLUSIONS: These changes in myocardial gene expression support the occurrence of reverse remodeling during chronic CRT. The changes are similar to those reported previously with beta-blockade, but were seen on top of standard drug therapies for heart failure.

Efficacy of transesophageal echocardiography-guided cardioversion of patients with atrial fibrillation at 6 months: a randomized controlled trial.

BACKGROUND: Electrical cardioversion in patients with atrial fibrillation (AF) is associated with an increased risk of stroke. We compared a transesophageal echocardiography (TEE)-guided strategy with a conventional strategy in patients with AF > 2 days' duration undergoing electrical cardioversion over a 6-month follow-up. METHODS: The ACUTE study was a multicenter, randomized, clinical trial, with 1222 patients. Six-month follow-up was available in 1034 patients (85%), 525 in the TEE group and 509 in the conventional group. The primary composite end points were cerebrovascular accident, transient ischemic attack, and peripheral embolism at 6 months, which was a prespecified time point. Secondary end points were hemorrhage, mortality, and sinus rhythm. RESULTS: At 6 months, there was no difference in composite embolic events between the TEE group and the conventional group (10 [2%] vs 4 [0.8%]; risk ratio (RR) 2.47, 95% CI 0.78-7.88; P = .11). However, the hemorrhagic rate was significantly lower in the TEE group (23 [4.4%] vs 38 [7.5%]; RR 0.58, 96% CI 0.35-0.97; P = .04). There was no difference between the 2 treatment groups in all-cause mortality (21 [4%] vs 14 [2.8%]; RR 1.48, 95% CI 0.76-2.92; P = .25) and in the occurrence of normal sinus rhythm between the 2 groups (305 [62.2%] vs 280 [58.1%]; P = .51). Sinus rhythm at 6 months was more common in the TEE-guided group, in those patients who had direct current cardioversion (238 [62.5%] vs 151 [53.9%]; P = .03). CONCLUSION: The TEE-guided strategy may be considered a clinically effective alternative to a conventional anticoagulation strategy for patients with AF of > 2 days' duration undergoing electrical cardioversion over a 6-month period.