Super and Nonresponders to Catheter Ablation for Atrial Fibrillation: A Quality-of-Life Assessment Using Patient Reported Outcomes.

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Predictors of long-term outcomes greater than 10 years after cardiac resynchronization therapy implantation.

BACKGROUND: Cardiac resynchronization therapy (CRT) is indicated in patients with medically refractory heart failure and wide QRS duration. While much is known about predictors of left ventricular (LV) remodeling after CRT implantation and short-term mortality, limited data exist on long-term outcomes after CRT placement. METHODS: We retrospectively reviewed all patients undergoing CRT implantation at our center between 2003 and 2008 and examined mortality using institutional electronic records, social security death index, and online obituary search. We included only patients with preimplant echoes with LV ejection fraction (LVEF) 35% or below. Variable selection was performed using stepwise regression and models were compared using goodness-of-fit criteria. A final model was validated with the bootstrap regression method. RESULTS: Out of the 877 CRT patients undergoing implantation during this time, 287 (32.7%) survived longer than 10 years. Significant (P < .05) predictors of survival in our multivariate model were age, left ventricular diastolic diameter, sex, presence of nonischemic vs ischemic cardiomyopathy, QRS duration, atrial fibrillation, BNP levels, and creatinine levels at the time of CRT implantation. A model using the odds ratios from these variables had a receiver operating curve with an area under the curve score of 0.816 (standard error, 0.019) at predicting survival or freedom from LVAD or heart transplant for longer than 10 years after CRT implantation. The specificity for factors 3 or above and 5 or above was 68% and 77%, respectively. CONCLUSION: A large proportion of patients are still alive 10 years after CRT implantation. Variables at the time of CRT implant can help provide prognostic information to patients and electrophysiologists to determine the long-term benefit and survival of patients after CRT implantation.

Risk factors for 1-year mortality among patients with cardiac implantable electronic device infection undergoing transvenous lead extraction: the impact of the infection type and the presence of vegetation on survival.

AIMS: Infections of cardiac implantable electronic devices (CIEDs) are infrequent but carry significant morbidity and mortality. We aimed to assess risk factors for 1-year mortality among patients with CIED infection and to evaluate if the type of infection and the presence of vegetation affect survival. METHODS AND RESULTS: We reviewed records of all patients with infected CIEDs who underwent transvenous lead extraction at our tertiary care centre between 2002 and 2008. Patients who presented with infection involving the device pocket were classified as 'pocket infection', and those who presented with bacteraemia with or without vegetation and a pocket that looked benign were classified as 'endovascular infection' (EVI). One-year mortality was examined using the social security death index. Five hundred and two patients were identified (68.5 ± 15 years); 289 (58%) had pocket infection and 213 (42%) had EVI. One-year mortality rate was 20%. Using multivariable Cox regression model, EVI was associated with significantly higher 1-year mortality (hazard ratio 2.1, P-value 0.0008). Among patients with EVI, 100 patients had vegetation on transoesophageal echo; however, there was no difference in 1-year mortality between patients with EVI and vegetation compared with patients with EVI and no vegetation (27, 27 vs. 40, 35%; P-value 0.188). Risk factors for 1-year mortality among patients with EVI included renal failure, worse functional class, and bleeding requiring transfusion. The presence of vegetation was not associated with increased 1-year mortality. CONCLUSION: One-year mortality is higher among patients with EVI compared with patients with pocket infection; this increased mortality does not seem to be related to the presence of vegetations.

Incidence, management, and outcomes of the arteriovenous fistula complicating transvenous lead extraction.

BACKGROUND: An arteriovenous (AV) fistula is an infrequently reported complication of transvenous lead extraction (TLE), but may be under-recognized. OBJECTIVE: To determine the incidence, management, and outcomes of the AV fistula complicating TLE. METHODS: All TLE procedures from July 2001 to December 2012 were reviewed. RESULTS: Of 2471 patients who underwent TLE, the AV fistula occurred in 8 (0.3%; 6 pacemaker and 2 implantable cardioverter-defibrillator) procedures. Patients who developed an AV fistula had longer lead implant duration (11.8 [interquartile range 7.7] vs 5.2 [interquartile range 7.0] years) and were more likely to have required a powered sheath (8 of 8 [100%] vs 1392 of 2463 [56.5%]) compared to those who did not. Other procedural and demographic details did not discriminate. All patients had a continuous bruit along the anterior chest wall. Catheter angiography was more sensitive (100%) than computed tomography (75%) or ultrasound (25%) for confirming the diagnosis and identifying the vessels involved. One fistula closed spontaneously, while others were closed with covered stents (4) or surgical glue (1). One attempt at closure failed, and one was diagnosed postmortem. Mortality related to the AV fistula was 3 of 8 (37.5%). Patients who died all had structural heart disease. In the 5 patients with normal hearts, the AV fistula was well tolerated for up to 2 years. CONCLUSIONS: An AV fistula is an infrequent, though possibly under-recognized, complication of TLE. It requires a high index of suspicion for early diagnosis, may present late, and may be associated with significant morbidity and mortality in patients with structural heart disease.

Assessment of left atrial mechanics in patients with atrial fibrillation: comparison between two-dimensional speckle-based strain and velocity vector imaging.

BACKGROUND: Two-dimensional (2D) speckle tracking-derived left atrial (LA) strain (ε) facilitates comprehensive evaluation of LA contractile, reservoir, and conduit function; however, its dependence on the individual software used for assessment has not been evaluated. The aim of this study was to compare LA ε derived from two different speckle-tracking software technologies, Velocity Vector Imaging (VVI) and 2D speckle-tracking echocardiography (STE). METHODS: VVI-derived and 2D STE-derived global longitudinal LA ε and ε rate (SR) were directly compared in 127 patients (mean age, 62 ± 10 years) with atrial fibrillation. Peak negative, peak positive, and total ε (corresponding to LA contractile, conduit, and reservoir function) were measured during sinus rhythm. Late negative (LA contraction), peak positive (left ventricular systole), and early negative (left ventricular early diastole) SR were also measured. RESULTS: The measurement of LA ε and SR by both software was feasible in high proportions of patients (93% with VVI and 93% with 2D STE). The average analysis of ε(negative) was -7.24 ± 3.87% by VVI and -7.30 ± 3.37% by 2D STE (P = .84). The average analysis of ε(positive) was 14.52 ± 5.82% by VVI and 10.74 ± 4.51% by 2D STE (P < .01). The average analysis of ε(total) was 21.76 ± 7.39% by VVI and 18.04 ± 5.98% by 2D STE (P < .01). VVI-derived and 2D STE-derived ε(positive), ε(negative), and ε(total) had good correlations with one another (R = 0.79, R = 0.75, and R = 0.80), with low mean differences. Late negative, peak positive, and early negative SR were correlated less well (R = 0.78, R = 0.71, and R = 0.67). CONCLUSIONS: LA ε measurement using both VVI and 2D STE is feasible in a large proportion of patients in clinical practice. VVI and 2D STE provide comparable LA ε and SR measurements for LA contractile function.

Cost comparison of ablation versus antiarrhythmic drugs as first-line therapy for atrial fibrillation: an economic evaluation of the RAAFT pilot study.

INTRODUCTION: Radiofrequency ablation (RFA) has become an accepted therapy for atrial fibrillation (AF). The objective of this study was to perform an economic evaluation of RFA versus antiarrhythmic drug therapy (AAD) as first-line treatment of symptomatic paroxysmal AF. METHODS: To estimate and compare the costs of RFA versus AAD, a decision analytic model was developed using data on AF recurrence, hospitalization rates, AAD use, and treatment crossover rates derived directly from the Randomized Trial of RFA versus AAD as First-Line Treatment of Symptomatic Atrial Fibrillation (RAAFT). Resource utilization was modeled to reflect Canadian clinical practice in AF management. Unit costs of healthcare interactions were based on available Canadian government resources and published literature. Costs were assessed based on intention-to-treat. Total expected costs were computed to include initial treatment, hospital stay, physician fees, diagnostic tests, and outpatient visits. Sensitivity analyses were performed to account for the uncertainties. The study was conducted from the third party payer's perspective and costs are reported in 2005 Canadian dollars with 3% discount rate used in the analysis. RESULTS: During the 2-month blanking period following therapy selection, total average costs for RFA and AAD were $10,465 and $2,556, respectively; at 1-year follow-up, these were $12,823 and $6,053; and total 2-year cumulative total average costs were $15,303 and $14,392. Sensitivity analyses did not alter the results, suggesting the model is robust. CONCLUSIONS: RFA as first-line treatment strategy in patients with symptomatic paroxysmal AF was cost neutral 2 years after the initial procedure compared to AAD.

Endoscopic fiberoptic assessment of balloon occlusion of the pulmonary vein ostium in humans: comparison with phased-array intracardiac echocardiography.

BACKGROUND: Anatomic pulmonary vein (PV) variants may affect the ability to position balloon catheter systems at the left atrium (LA)-PV junction with complete circumferential contact, resulting in ineffective PV isolation. OBJECTIVES: This feasibility study was performed to assess the use of the fiberoptic endoscopic light ring balloon catheter (ELRBC) in accessing the PVs and achieving adequate contact at the LA-PV junction, as visualized by phased-array intracardiac echocardiography (ICE). METHODS: We enrolled five men (mean age 59 +/- 8 years) with drug-refractory atrial fibrillation. The ELRBC consisted of a 25-mm balloon catheter with an integral endoscope contained within the balloon and a custom deflectable sheath. At the end of conventional PV isolation, the ELRBC was inserted into the LA in an attempt to position the balloon at each PV ostium. The real position of the ELRBC at this level was assessed by ICE in all patients. RESULTS: All but two PVs (right inferior PVs) (89%) were accessed with the ELRBC in a mean time of 17 +/- 3 minutes, and complete circumferential contact was visualized with the fiberoptic endoscopic component in 15 of 16 PVs accessed (94%). Contact was also confirmed by the absence of color Doppler flow through the balloon-occluded PV, as seen on ICE. On two occasions a gap was seen with the fiberoptic endoscope and visualized by the ICE only after optimization of the echo window. No complications were observed. CONCLUSIONS: The ELRBC is able to access the PV without complications. The endoscope and ICE were complementary for positioning of the balloon at the LA-PV junction and for the definition of circumferential contact.