Clinical predictors of cardiac magnetic resonance late gadolinium enhancement in patients with atrial fibrillation.

AIMS: This study aims to examine the association of clinical co-morbidities with the presence of left atrial (LA) late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR). Previous studies have established the severity of LA LGE to be associated with atrial fibrillation (AF) recurrence following AF ablation. We sought to determine whether baseline clinical characteristics were associated with LGE extent among patients presenting for an initial AF ablation. METHODS AND RESULTS: The cohort consisted of 179 consecutive patients with no prior cardiac ablation procedures who underwent pre-procedure LGE-CMR. The extent of LA LGE for each patient was calculated using the image intensity ratio, normalized to the mean blood pool intensity, corresponding to a bipolar voltage ≤0.3 mV. The association of LGE extent with baseline clinical characteristics was examined using non-parametric and multivariable models. The mean age of the cohort was 60.9 ± 9.6 years and 128 (72%) were male. In total, 56 (31%) patients had persistent AF. The mean LA volume was 118.4 ± 41.6 mL, and the mean LA LGE extent was 14.1 ± 10.4%. There was no association with any clinical variables with LGE extent by quartiles in the multivariable model. Extent of LGE as a continuous variable was positively, but weakly associated with LA volume in a multivariable model adjusting for age, body mass index, AF persistence, and left ventricular ejection fraction (1.5% scar/mL, P = 0.038). CONCLUSION: In a cohort of patients presenting for initial AF ablation, the presence of pre-ablation LA LGE extent was weakly, but positively associated with increasing LA volume.

Factors impacting complication rates for catheter ablation of atrial fibrillation from 2003 to 2015.

Aims: Complications from catheter ablation for atrial fibrillation (AF) are well described. Changing aspects of AF ablation including patient populations referred, institutional experience, and emerging catheter and pharmacological options may impact complication rates. We assessed procedural complication trends in AF ablation patients from 2003­2015 to identify what factors affect adverse event rates. Methods and Results: We evaluated consecutively enrolled patients undergoing initial AF ablation from 2003 through 2015. Statistical analyses were performed to identify predictors of increased risk for major complications, which were defined as death, stroke, atrio-oesophageal fistula, phrenic nerve injury, cardiovascular events requiring blood transfusions or procedural interventions, or non-cardiovascular events requiring intervention. A total of 1475 patients (mean age 59.5 ± 10.5, 82% male) were evaluated. Major complications occurred in 3.9% (n = 58) of cases, including vascular access-site haematoma (1.3%), cardiac tamponade (1.1%), and cerebrovascular accident (CVA) (0.9%). Univariate analysis revealed increased risk of complications associated with hypertension (P = 0.048), CHA2DS2VASc score ≥1 (P = 0.015), and early institutional experience (P = 0.003). Populations with higher CHA2DS2VASc scores underwent AF ablation more frequently over time (P < 0.001). Novel catheters and anticoagulants did not appreciably affect complication rates. Multivariate analysis adjusting for hypertension, CHA2DS2VASc score, and institutional experience showed that higher CHA2DS2VASc score and early institutional experience were independent predictors of adverse events. Conclusion: Patient characteristics reflected in CHA2DS2VASc scoring and early institutional experience predict increased complication rates following AF ablation. Despite more patients with higher CHA2DS2VASc scores undergoing AF ablation, complication rates fell over time as institutional experience increased.

Right Ventricular Dysfunction Complicates Time in Therapeutic Range in Heart Failure Patients Receiving Warfarin.

AIM: We aimed to evaluate the effect of echocardiographically demonstrated right ventricular dysfunction (RVD) on time in therapeutic range (TTR) in heart failure (HF) patients receiving warfarin therapy. METHODS: A total of 893 consecutive HF patients were included and classified into 4 different subgroups: HF with preserved ejection fraction (HFpEF) without RVD (n = 373), HF with reduced EF (HFrEF) without RVD (n = 215), HFpEF with RVD (n = 106) and HFrEF with RVD (n = 199). Groups were compared according to baseline, demographic and clinical data and the characteristics of warfarin therapy. RESULTS: Presence of RVD yielded lower median TTR values both in HFpEF and HFrEF patients. RVD, current smoking, New York Heart Association functional class III/IV, hypertension, diabetes mellitus, pulmonary disease, prior transient ischemic attack or stroke, chronic kidney disease (CKD) stage 4/5 and CKD stage 3 were found to be independent predictors of poor anticoagulation control in multivariate logistic regression analysis. CONCLUSIONS: The present study demonstrated that presence of RVD in HF increases the risk for poor anticoagulation.

Fully automatic segmentation of left atrium and pulmonary veins in late gadolinium-enhanced MRI: Towards objective atrial scar assessment.

PURPOSE: To realize objective atrial scar assessment, this study aimed to develop a fully automatic method to segment the left atrium (LA) and pulmonary veins (PV) from late gadolinium-enhanced (LGE) magnetic resonance imaging (MRI). The extent and distribution of atrial scar, visualized by LGE-MRI, provides important information for clinical treatment of atrial fibrillation (AF) patients. MATERIALS AND METHODS: Forty-six AF patients (age 62 ± 8, 14 female) who underwent cardiac MRI prior to RF ablation were included. A contrast-enhanced MR angiography (MRA) sequence was acquired for anatomy assessment followed by an LGE sequence for LA scar assessment. A fully automatic segmentation method was proposed consisting of two stages: 1) global segmentation by multiatlas registration; and 2) local refinement by 3D level-set. These automatic segmentation results were compared with manual segmentation. RESULTS: The LA and PVs were automatically segmented in all subjects. Compared with manual segmentation, the method yielded a surface-to-surface distance of 1.49 ± 0.65 mm in the LA region when using both MRA and LGE, and 1.80 ± 0.93 mm when using LGE alone (P < 0.05). In the PV regions, the distance was 2.13 ± 0.67 mm and 2.46 ± 1.81 mm (P < 0.05), respectively. The difference between automatic and manual segmentation was comparable to the interobserver difference (P = 0.8 in LA region and P = 0.7 in PV region). CONCLUSION: We developed a fully automatic method for LA and PV segmentation from LGE-MRI, with comparable performance to a human observer. Inclusion of an MRA sequence further improves the segmentation accuracy. The method leads to automatic generation of a patient-specific model, and potentially enables objective atrial scar assessment for AF patients. J. Magn. Reson. Imaging 2016;44:346-354.

Asymptomatic Tricuspid Stenosis Following a Complex Lead Extraction Procedure.

The number of transvenous extraction procedures for leads of intracardiac rhythm devices increased recently and the most common reason for lead extraction is device infection. In some cases, combined use of two different techniques is necessary. Long-term results of this approach are not clear. In this case report, we present a patient with biventricular implantable cardioverter defibrillator who underwent percutaneous hardware removal due to recurrent pacemaker pocket infections. Mechanical dilator sheath removal and Needle's Eye Snare were used in the same patient. Although asymptomatic, tricuspid stenosis was detected three years after the operation.

Safety of implanted cardiac devices in an MRI environment.

Magnetic resonance imaging (MRI) has evolved into an essential diagnostic modality for the evaluation of various conditions. In line with the increase in MRI applications, the use of cardiac implantable electronic devices (CIED) is growing and many of the CEID recipients of today may require MRI examinations in the future. Traditionally, MRI examination of CIED recipients has been considered a contraindication. However, recent studies have provided strong evidence that MRI can safely be performed in selected patients with specific precautions. This review highlights the interactions of MRI with CIEDs, summarizes the literature, and outlines the Johns Hopkins Safety Protocol.

Preconception Counseling for a Patient With a Mechanical Tricuspid Valve.

A 37-year-old woman with mechanical tricuspid valve thrombosis presented for preconception consultation. Multimodality imaging confirmed a malfunctioning bileaflet mechanical tricuspid valve with both leaflets fixed and open. This case highlights the key discussions held by the multidisciplinary pregnancy heart team.

Infections of implantable cardiac rhythm devices: predisposing factors and outcome.

BACKGROUND AND OBJECTIVE: Infection is a serious complication of cardiac devices. We aimed to describe predisposing factors and outcome of permanent pacemaker (PPM) and implantable cardioverter/defibrillator (ICD) infections. METHOD: We reviewed cardiac device infections diagnosed at the Yuksek Ihtisas Hospital Ankara, Turkey, between 2004 and 2010 retrospectively. Demographic and clinical data were collected, descriptive analysis was performed. RESULTS: From 2004 to 2010, a total of 1916 devices were implanted. Thirty-four cases of confirmed device infections were identified giving an infection rate of 1.7%. Seventy-three percent of the cases were men. Mean age was 58 +/- 19 years. Twenty-two patients had a PPM, 12 had an ICD or cardiac resynchronization therapy (CRT). Diabetes mellitus, hypertension, cardiac failure, anaemia and immune suppression were prominent comorbidities. Previously, 6 (17%) patients had a history of replacement, 6 (17%) had revision, 3 (8%) had haematoma. Ten (29%) patients reported a history of long hospital stay and 13 (38%) patients had multiple hospitalizations. Pocket infection (70%) was the most common clinical presentation. Ninety-one percent of patients were cured with both device removal and antibiotic administration. Complications of cardiac device infections included septic emboli, acute renal failure, inotropic infusion requirement which were mostly seen among patients with endocarditis. Five patients suffered relapsing infection.Three patients died, among them two had infective endocarditis. CONCLUSION: Cardiac device infections have been encountered more often in recent years. Cure of device infections is achievable in a majority of patients treated with antimicrobial treatment and complete device removal although device-related endocarditis can have an aggressive course.

Which is the best for the warfarin monitoring: Following up by fixed or variable physician?

Objective: Warfarin therapy has some difficulties in terms of close monitoring and dosage. This study aims to evaluate the effect of same-fixed versus different-variable physician-based monitoring of warfarin therapy on treatment quality and clinical end-points. Methods: A total of 625 consecutive patients requiring warfarin treatment were enrolled at seven centers. INR values of the patients measured at each visit and registered to hospital database were recorded. Time in therapeutic range (TTR) was calculated using linear interpolation method (Rosendaal's method). A TTR value of ≥65% was considered as effective warfarin treatment. If a patient was evaluated by the same-fixed physician at each INR visit, was categorized into the same-physician (SP) group. In contrast, if a patient was evaluated by different-variable physicians at each INR visit, was categorized into variable physician (VP) group. Enrolled patients were followed up for bleeding and embolic events. Results: One hundred and fifty-six patients (24.9%) were followed by SP group, 469 (75.1%) patients were followed by VP group. Median TTR value of the VP group was lower than that of SP group (56.2% vs. 65.1%, respectively, p=0.009). During median 25.5 months (9-36) of follow-up, minor bleeding, major bleeding and cerebral embolic event rates were higher in VP group compared to SP group (p<0.001, p=0.023, p<0.001, respectively). In multivariate analysis, INR monitoring by VP group was found to be an independent predictor of increased risk of bleeding events (OR 2.55, 95% CI 1.64-3.96, p<0.001) and embolism (OR 3.42, 95% CI 1.66-7.04, p=0.001). Conclusion: INR monitoring by same physician was associated with better TTR and lower rates of adverse events during follow-up. Hence, it is worth encouraging an SP-based outpatient follow-up system at least for where warfarin therapy is the only choice.

Association of Rate-Dependent Conduction Block Between Eccentric Coronary Sinus to Left Atrial Connections With Inducible Atrial Fibrillation and Flutter.

BACKGROUND: We sought to describe the prevalence and variability of coronary sinus (CS) and left atrial (LA) myocardium connections, their susceptibility to rate-dependent conduction block, and association with atrial fibrillation (AF) and flutter induction. METHODS AND RESULTS: The study cohort included 30 consecutive AF patients (age 63.3±10.5 years, 63% male). Multipolar catheters were positioned in the CS, high right atrium (HRA), and LA parallel to and near the CS. Trains of 10 pacing stimuli were delivered during sinus rhythm from each of the following sites: CS proximal (CSp), CS distal (CSd), LA septum (LAs), lateral LA (LAl), and HRA, at the following cycle lengths: 1000, 500, 400, 300, and 250 ms, while recording from the other catheters. With the CS 9 to 10 bipole just inside the CS ostium, CS-LA connections were observed in 100% at CS 9 to 10, 30% at CS 7 to 8, 23% at CS 5 to 6, 23% at CS 3 to 4, and 97% at CS 1 to 2. Eighteen patients (60%) had AF/atrial flutter induced. Rate-dependent conduction block of a CS-LA connection at cycle length of ≥250 ms was present in 17 (94%) of those with versus none of those without AF/atrial flutter induction (P<0.001). CONCLUSIONS: Rate-dependent eccentric CS-LA conduction block is associated with AF/atrial flutter induction in patients with drug-refractory AF undergoing ablation. The presence of dual muscular CS-LA connections, coupled with unidirectional block in one limb, seems to serve as a substrate for single or multiple reentry beats, and arrhythmia induction.

Association of left atrial epicardial adipose tissue with electrogram bipolar voltage and fractionation: Electrophysiologic substrates for atrial fibrillation.

BACKGROUND: Epicardial adipose tissue (EAdT) is metabolically active and likely contributes to atrial fibrillation (AF) through the release of inflammatory cytokines into the myocardium or through its rich innervation with ganglionated plexi at the pulmonary vein ostia. The electrophysiologic mechanisms underlying the association between EAdT and AF remain unclear. OBJECTIVE: The purpose of this study was to investigate the association of EAdT with adjacent myocardial substrate. METHODS: Thirty consecutive patients who underwent cardiac computed tomography as well as electroanatomic mapping in sinus rhythm before an initial AF ablation procedure were studied. Semiautomatic segmentation of atrial EAdT was performed and registered anatomically to the voltage map. RESULTS: In multivariable regression analysis clustered by patient, age (-0.01 per year) and EAdT (-0.29) were associated with log bipolar voltage as well as low-voltage zones (<0.5 mV). Age (odds ratio [OR]: 1.02 per year), male gender (OR: 3.50), diabetes (OR: 2.91), hypertension (OR: 2.55), and EAdT (OR: 8.56) were associated with fractionated electrograms, and age (OR: 2.80), male gender (OR: 3.00), and EAdT (OR: 7.03) were associated with widened signals. Age (OR: 1.03 per year) and body mass index (OR: 1.06 per kg/m2) were associated with atrial fat. CONCLUSION: The presence of overlaying EAdT was associated with lower bipolar voltage and electrogram fractionation as electrophysiologic substrates for AF. EAdT was not a statistical mediator of the association between clinical variables and AF substrate. Body mass index was directly associated with the presence of EAdT in patients with AF.

Association of Left Atrial Local Conduction Velocity With Late Gadolinium Enhancement on Cardiac Magnetic Resonance in Patients With Atrial Fibrillation.

BACKGROUND: Prior studies have demonstrated regional left atrial late gadolinium enhancement (LGE) heterogeneity on magnetic resonance imaging. Heterogeneity in regional conduction velocities is a critical substrate for functional reentry. We sought to examine the association between left atrial conduction velocity and LGE in patients with atrial fibrillation. METHODS AND RESULTS: LGE imaging and left atrial activation mapping were performed during sinus rhythm in 22 patients before pulmonary vein isolation. The locations of 1468 electroanatomic map points were registered to the corresponding anatomic sites on 469 axial LGE image planes. The local conduction velocity at each point was calculated using previously established methods. The myocardial wall thickness and image intensity ratio defined as left atrial myocardial LGE signal intensity divided by the mean left atrial blood pool intensity was calculated for each mapping site. The local conduction velocity and image intensity ratio in the left atrium (mean ± SD) were 0.98 ± 0.46 and 0.95 ± 0.26 m/s, respectively. In multivariable regression analysis, clustered by patient, and adjusting for left atrial wall thickness, conduction velocity was associated with the local image intensity ratio (0.20 m/s decrease in conduction velocity per increase in unit image intensity ratio, P<0.001). CONCLUSIONS: In this clinical in vivo study, we demonstrate that left atrial myocardium with increased gadolinium uptake has lower local conduction velocity. Identification of such regions may facilitate the targeting of the substrate for reentrant arrhythmias.

Cardiac magnetic resonance for prediction of arrhythmogenic areas.

Catheter ablation has been widely used to manage recurrent atrial and ventricular arrhythmias. It has been established that contrast-enhanced magnetic resonance can accurately characterize the myocardium. In this review, we summarize the role of cardiac magnetic resonance in identification of arrhythmogenic substrates, and the potential utility of cardiac magnetic resonance for catheter ablation of complex atrial and ventricular arrhythmias.

Red cell distribution width predicts mortality in infective endocarditis.

BACKGROUND: Infective endocarditis (IE) is associated with significant morbidity and mortality. Red cell distribution width (RDW) is a recently recognized biomarker of adverse outcome in a number of acute and chronic conditions. AIM: To investigate the relationship between RDW and 1-year survival in patients with IE. METHODS: Clinical records from two tertiary centres were used to analyze data from patients with definite IE. Clinical, echocardiographic and biochemical variables were evaluated along with RDW. One-year survival status after index hospitalization was identified for each patient. RESULTS: One hundred consecutive patients (mean age 47.8±16.7 years; 61% men) with definite IE were enrolled. According to receiver operating characteristic curve analysis, the optimal RDW cut-off value for predicting mortality was 15.3% (area under the curve 0.70; P=0.001). Forty-one patients (41%) died within 1 year; of these, 88% had RDW results>15.3%. Univariate Cox proportional-hazards analysis showed that RDW>15.3%, heart failure, renal failure, cardiac abscess, severe valvular regurgitation and presence of dehiscence were associated with increased mortality. Multivariable Cox proportional-hazards analysis revealed that renal failure (hazard ratio [HR] 3.21, 95% confidence interval [CI] 1.35-7.59; P=0.008), heart failure (HR 2.77, 95% CI 1.1-6.97; P=0.03) and RDW>15.3% (HR 3.07, 95% CI 1.06-8.86; P=0.03) were independent predictors of mortality in patients with IE. CONCLUSION: According to our results, mortality is high in patients with IE. RDW is a promising biomarker for predicting 1-year survival rates in these patients.

Factors influencing the use of ambulance among patients with acute coronary syndrome: results of two centers in Turkey.

OBJECTIVE: In this study, we aimed to identify the factors influencing the use of ambulance among patients admitted to two Turkish hospitals with acute coronary syndrome (ACS). METHODS: Overall, 330 with a mean age of 55±13 years, hospitalized patients with ACS at 2 different hospitals were included in this prospective cohort study. The factors influencing the use of ambulance hospital were investigated through a questionnaire. The comparisons were made between two groups regarding use of ambulance. The predictors of the use of ambulance were determined using multiple logistic regression analysis. RESULTS: Despite the high rate of knowing the emergency service number of "112", of the 330 patents, only 96 (29%) used ambulance. Ambulance users had shorter arrival duration with median of 60 min vs 120 min (p=0.03). Presenting with ST elevation myocardial infarction (OR=3.127, 95% CI: 1.555-6.2877, p<0.001), severity of chest pain (OR=2.665, 95% CI: 1.938-3.665, p<0.001), presence of accompanying symptoms such as dyspnea (OR= 5.510, 95% CI: 2.614-11.614, p<0.001), dizziness (OR=4.172, 95% CI: 1.901-9.154, p<0.001) and vomiting (OR=3.756, 95% CI: 1.521-9.272, p=0.004), knowledge of cardiac risk factors (OR=10.512, 95% CI: 4.497-24.572, p<0.001) or chest pain related to heart attack and the importance of quickly seeking for medical care by calling ambulance (OR= 4.184, 95% CI: 2.528-6.926, p<0.001) are the factors associated with ambulance use. CONCLUSION: Using ambulance was in a very low rate among our study patients with ACS. Severity of symptoms, type of ACS and knowledge are seemed to be related with increased ambulance use. Informative health educational programs can be organized to achieve a behavioral change in using of ambulance.