John Rickard

Use of dabigatran for periprocedural anticoagulation in patients undergoing catheter ablation for atrial fibrillation

Background—Pulmonary vein isolation (PVI) for atrial fibrillation is associated with a transient increased risk of thromboembolic and hemorrhagic events. We hypothesized that dabigatran can be safely used as an alternative to continuous warfarin for the periprocedural anticoagulation in PVI. Methods and Results—A total of 999 consecutive patients undergoing PVI were included; 376 patients were on dabigatran (150 mg), and 623 patients were on warfarin with therapeutic international normalized ratio. Dabigatran was held 1 to 2 doses before PVI and restarted at the conclusion of the procedure or as soon as patients were transferred to the nursing floor. Propensity score matching was applied to generate a cohort of 344 patients in each group with balanced baseline data. Total hemorrhagic and thromboembolic complications were similar in both groups, before (3.2% versus 3.9%; P=0.59) and after (3.2% versus 4.1%; P=0.53) matching. Major hemorrhage occurred in 1.1% versus 1.6% (P=0.48) before and 1.2% versus 1.5% (P=0.74) after matching in the dabigatran versus warfarin group, respectively. A single thromboembolic event occurred in each of the dabigatran and warfarin groups. Despite higher doses of intraprocedural heparin, the mean activated clotting time was significantly lower in patients who held dabigatran for 1 or 2 doses than those on warfarin. Conclusions—Our study found no evidence to suggest a higher risk of thromboembolic or hemorrhagic complications with use of dabigatran for periprocedural anticoagulation in patients undergoing PVI compared with uninterrupted warfarin therapy.

HRS Expert Consensus Statement on remote interrogation and monitoring for cardiovascular implantable electronic devices

DavidSlotwiner,MD, FHRS, FACC(Chair),Niraj Varma,MD,PhD, FRCP(Co-chair), JosephG.Akar,MD,PhD, George Annas, JD, MPH, Marianne Beardsall, MN/NP, CCDS, FHRS, Richard I. Fogel, MD, FHRS, Nestor O. Galizio, MD, Taya V. Glotzer, MD, FHRS, FACC, Robin A. Leahy, RN, BSN, CCDS, FHRS, Charles J. Love, MD, CCDS, FHRS, FACC, FAHA, Rhondalyn C. McLean, MD, Suneet Mittal, MD, FHRS, Loredana Morichelli, RN, MSN, Kristen K. Patton, MD, Merritt H. Raitt, MD, FHRS, Renato Pietro Ricci, MD, John Rickard, MD, MPH, Mark H. Schoenfeld, MD, CCDS, FHRS, FACC, FAHA, Gerald A. Serwer, MD, FHRS, FACC, Julie Shea, MS, RNCS, FHRS, CCDS, Paul Varosy, MD, FHRS, FACC, FAHA, Atul Verma, MD, FHRS, FRCPC, Cheuk-Man Yu, MD, FACC, FRCP, FRACP From the Hofstra School of Medicine, North Shore Long Island Jewish Health System, New Hyde Park, New York, Cleveland Clinic, Cleveland, Ohio, Yale University School of Medicine, New Haven, Connecticut, Boston University School of Public Health, Boston, Massachusetts, Southlake Regional Health Centre, Newmarket, Ontario, Canada, St. Vincent Medical Group, Indianapolis, Indiana, Favaloro Foundation University Hospital, Buenos Aires, Argentina, Hackensack University Medical Center, Hackensack, New Jersey, Sanger Heart & Vascular Institute, Carolinas HealthCare System, Charlotte, North Carolina, New York University Langone Medical Center, New York City, New York, University of Pennsylvania Health System, Philadelphia, Pennsylvania, The Arrhythmia Institute at Valley Hospital, New York, New York, Department of Cardiovascular Diseases, San Filippo Neri Hospital, Rome, Italy, University of Washington, Seattle, Washington, VA Portland Health Care System, Oregon Health & Science University, Knight Cardiovascular Institute, Portland, Oregon, Johns Hopkins University, Baltimore, Maryland, Yale University School of Medicine, Yale-New Haven Hospital Saint Raphael Campus, New Haven, Connecticut, University of Michigan Congenital Heart Center, University of Michigan Health Center, Ann Arbor, Michigan, Brigham and Women’s Hospital, Boston, Massachusetts, Veterans Affairs Eastern Colorado Health Care System, University of Colorado, Denver, Colorado, and Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China.

Characterization of super-response to cardiac resynchronization therapy.

BACKGROUNDnIn patients with chronic systolic heart failure who undergo cardiac resynchronization therapy (CRT), improvements in left ventricular ejection fraction (LVEF) and reductions in left ventricular volume are generally modest. A minority of patients experience a dramatic response to CRT (super-responders), but the attributes associated with these patients have not been fully characterized.nnnOBJECTIVEnThe purpose of this study was to identify baseline clinical attributes of super-responders and to assess the survival benefit associated with this response.nnnMETHODSnWe reviewed clinical, echocardiographic, and ECG data from a cohort of 233 patients undergoing new implantation of a CRT device between December 2001 and November 2006. All patients had a baseline LVEF < or =40% and New York Heart Association class II to IV symptoms on standard medical therapy. Patients whose absolute LVEF improved by > or =20% were termed super-responders. A multivariate model was constructed to determine factors predictive of super-response, and an assessment of mortality was made.nnnRESULTSnIn this cohort of 233 patients, 32 (13.7%) met criteria for super-response. In univariate analysis, super-responders were more likely to be female and have a native left bundle branch block, lower preimplant brain natriuretic peptide and red cell distribution width levels, and smaller baseline left ventricular volumes with trends toward having more nonischemic cardiomyopathy and midventricular lead positions. In multivariate analysis, only left bundle branch block remained significantly associated with super-response. Super-responders had a considerably lower incidence of mortality compared to non-super-responders (9.4% vs 43.2%, P = .006) at mean follow-up of 5.5 +/- 1.2 years.nnnCONCLUSIONnBaseline left bundle branch block is strongly associated with super-response to CRT. Super-responders derive better long-term outcomes with CRT than do non-super-responders.

Differential Response to Cardiac Resynchronization Therapy and Clinical Outcomes According to QRS Morphology and QRS Duration

OBJECTIVESnThe goal of this study was to examine the relative impact of QRS morphology and duration in echocardiographic responses to cardiac resynchronization therapy (CRT) and clinical outcomes.nnnBACKGROUNDnAt least one-third of all patients treated with CRT fail to derive benefit. Patients without left bundle branch block (LBBB) or patients with smaller QRS duration (QRSd) respond less or not at all to CRT.nnnMETHODSnWe retrospectively assessed baseline characteristics, clinical and echocardiographic response, and outcomes of all patients who received CRT at our institution between December 2003 and July 2007. Patients were stratified into 4 groups according to their baseline QRS morphology and QRSd.nnnRESULTSnA total of 496 patients were included in the study; 216 (43.5%) had LBBB and a QRSd ≥150 ms, 85 (17.1%) had LBBB and QRSd <150 ms, 92 (18.5%) had non-LBBB and a QRSd ≥150 ms, and 103 (20.8%) had non-LBBB and QRSd <150 ms. Echocardiographic response (change in ejection fraction) was better in patients with LBBB and QRSd ≥150 ms (12 ± 12%) than in those with LBBB and QRSd <150 ms (8 ± 10%), non-LBBB and QRSd ≥150 ms (5 ± 9%), and non-LBBB and QRSd <150 ms (3 ± 11%) (p < 0.0001). In a multivariate stepwise model with change in ejection fraction as the dependent variable, the presented classification was the most important independent variable (p = 0.0003). Long-term survival was better in LBBB patients with QRSd ≥150 ms (p = 0.02), but this difference was not significant after adjustment for other baseline characteristics (p = 0.15).nnnCONCLUSIONSnQRS morphology is a more important baseline electrocardiographic determinant of CRT response than QRSd.

Predictors of Response to Cardiac Resynchronization Therapy in Patients With a Non-Left Bundle Branch Block Morphology

Patients with non-left bundle branch block (LBBB) morphologies are thought to derive less benefit from cardiac resynchronization therapy (CRT) than those with LBBB. However, some patients do exhibit improvement. The characteristics associated with a response to CRT in patients with non-LBBB morphologies are unknown. Clinical, electrocardiographic, and echocardiographic data were collected from 850 consecutive patients presenting for a new CRT device. For inclusion, all patients had a left ventricular ejection fraction of ≤35%, a QRS duration of ≥120 ms, and baseline and follow-up echocardiograms available. Patients with a paced rhythm or LBBB were excluded. The response was defined as an absolute decrease in left ventricular end-systolic volume of ≥10% from baseline. Multivariate models were constructed to identify variables significantly associated with the response and long-term outcomes. A total of 99 patients met the inclusion criteria. Of these 99 patients, 22 had right bundle branch block and 77 had nonspecific intraventricular conduction delay; 52.5% met the criteria for response. On multivariate analysis, the QRS duration was the only variable significantly associated with the response (odds ratio per 10-ms increase 1.23, 95% confidence interval 1.01 to 1.52, p = 0.048). During a mean follow-up of 5.4 ± 0.9 years, 65 patients died or underwent heart transplant or left ventricular assist device placement. On multivariate analysis, the QRS duration was inversely associated with poor long-term outcomes (hazard ratio per 10-ms increase 0.79, 95% confidence interval 0.66 to 0.94, p = 0.005). In patients with advanced heart failure and non-LBBB morphologies, a wider baseline QRS duration is an important determinant of enhanced reverse ventricular remodeling and improved long-term outcomes after CRT.

The QRS narrowing index predicts reverse left ventricular remodeling following cardiac resynchronization therapy

Background: u2002The relationship between QRS narrowing and response to cardiac resynchronization therapy (CRT) has been controversial.

Association of Left Atrial Function and Left Atrial Enhancement in Patients With Atrial Fibrillation Cardiac Magnetic Resonance Study

Atrial fibrillation (AF) is associated with extensive abnormalities in atrial structure and function1-3. It is well-established that structural atrial changes precede the development of AF and progress with increased duration of sustained AF4. The changes in atrial function impair not only the booster pump function but also the atrial reservoir and conduit functions during ventricular systole and early diastole 5, 6. Progressive atrial remodeling includes fibrotic changes that promote AF maintenance7. This idea is supported by observations of increased left atrial (LA) fibrosis in patients with long-standing persistent AF 4. LA structural and functional remodeling is associated with increased incidence of AF, as well as AF recurrence after cardioversion or ablation8-11. n nLate gadolinium enhanced (LGE) cardiac magnetic resonance (CMR) can noninvasively quantify the extent of LA fibrosis12, 13. Atrial function is commonly evaluated by speckle-tracking echocardiography; however, the technique is limited for resolution of the thin and asymmetric LA myocardium and for the analysis of the posterior LA where most of the fibrosis is located7. In contrast, myocardial motion can be accurately tracked with CMR due to its ability to accurately define endocardial and epicardial borders14. CMR-feature tracking, a novel post–processing technique which tracks myocardial motion using cine CMR images, has recently been developed15-19. In this study, we sought to examine the association of LA fibrosis measured with LGE-CMR with phasic LA remodeling measured with feature-tracking CMR in patients with AF. We hypothesized that increased atrial LGE is associated with reduced LA function as assessed by feature tracking CMR.Background—Atrial fibrillation (AF) is associated with left atrial (LA) structural and functional changes. Cardiac magnetic resonance late gadolinium enhancement (LGE) and feature-tracking are capable of noninvasive quantification of LA fibrosis and myocardial motion, respectively. We sought to examine the association of phasic LA function with LA enhancement in patients with AF. Methods and Results—LA structure and function was measured in 90 patients with AF (age 61±10 years; 76% men) referred for ablation and 14 healthy volunteers. Peak global longitudinal LA strain, LA systolic strain rate, and early and late diastolic strain rates were measured using cine–cardiac magnetic resonance images acquired during sinus rhythm. The degree of LGE was quantified. Compared with patients with paroxysmal AF (60% of cohort), those with persistent AF had larger maximum LA volume index (56±17 versus 49±13 mL/m2; P=0.036), and increased LGE (27.1±11.7% versus 36.8±14.8%; P<0.001). Aside from LA active emptying fraction, all LA parameters (passive emptying fraction, peak global longitudinal LA strain, systolic strain rate, early diastolic strain rate, and late diastolic strain rate) were lower in patients with persistent AF (P<0.05 for all). Healthy volunteers had less LGE and higher LA functional parameters compared with patients with AF (P<0.05 for all). In multivariable analysis, increased LGE was associated with lower LA passive emptying fraction, peak global longitudinal LA strain, systolic strain rate, early diastolic strain rate, and late diastolic strain rate (P<0.05 for all). Conclusions—Increased LA enhancement is associated with decreased LA reservoir, conduit, and booster pump functions. Phasic measurement of LA function using feature-tracking cardiac magnetic resonance may add important information about the physiological importance of LA fibrosis.

Usefulness of Cardiac Resynchronization Therapy in Patients With Adriamycin-Induced Cardiomyopathy

Adriamycin is a chemotherapeutic agent that can cause severe cardiotoxicity, which potentially carries a poorer long-term prognosis than other forms of cardiomyopathy. Cardiac resynchronization therapy (CRT) has been shown to improve quality of life, exercise capacity, left ventricular ejection fraction, and survival in selected patients with heart failure. It is unclear if patients with Adriamycin-induced cardiomyopathy (AIC) respond to CRT. We reviewed clinical and echocardiographic data on 18 consecutive patients with AIC who underwent implantation of a CRT device at the Cleveland Clinic from February 2000 to April 2007. Changes in clinical and echocardiographic parameters were compared to 189 consecutive patients with other forms of nonischemic cardiomyopathy (NIC) using similar end points. Patients with AIC demonstrated significant improvements in ejection fraction, left ventricular end-diastolic and end-systolic diameters, mitral regurgitation, and New York Heart Association functional class with CRT. These changes were similar to patients in the NIC cohort. In conclusion, patients with AIC may derive a significant echocardiographic and symptomatic benefit from CRT, which is similar to that seen in other forms of NIC.

Cardiac Resynchronization Therapy in CKD: A Systematic Review

BACKGROUNDnCardiac resynchronization therapy (CRT) confers morbidity and mortality benefits to selected patients with heart failure. This systematic review examined effects of CRT in CKD patients (estimated GFR [eGFR] <60 ml/min per 1.73 m(2)).nnnDESIGN, SETTING, PARTICIPANTS, & MEASUREMENTSnMEDLINE and Scopus (from 1990 to December 2012) and conference proceedings abstracts were searched for relevant observational studies and randomized controlled trials (RCTs). Studies comparing the following outcomes were included: (1) CKD patients with and without CRT and (2) CKD patients with CRT to non-CKD patients with CRT. Mortality, eGFR, and left ventricular ejection fraction data were extracted and pooled when appropriate using a random-effects model.nnnRESULTSnEighteen studies (14 observational studies and 4 RCTs) were included. There was a modest improvement in eGFR with CRT among CKD patients (mean difference 2.30 ml/min per 1.73m(2); 95% confidence interval, 0.33 to 4.27). Similarly, there was a significant improvement in left ventricular ejection with CRT in CKD patients (mean difference 6.24%; 95% confidence interval, 3.46 to 9.07). Subgroup analysis of three RCTs reported lower rates of death or hospitalization for heart failure with CRT (versus other therapy) in the CKD population. Survival outcomes of CKD patients (compared with the non-CKD population) with CRT differed among observational studies and RCTs.nnnCONCLUSIONSnCRT improves left ventricular and renal function in the CKD population with heart failure. Given the increasing use of cardiac devices, further studies examining the effects of CRT on mortality in CKD patients, particularly those with advanced kidney disease, are warranted.

Lack of regional association between atrial late gadolinium enhancement on cardiac magnetic resonance and atrial fibrillation rotors

BACKGROUNDnThe extent of left atrial (LA) late gadolinium enhancement (LGE), as a surrogate for fibrosis, has been associated with atrial fibrillation (AF) recurrence after catheter ablation. Furthermore, there is ex vivo evidence that islands of fibrosis may anchor fibrillatory rotors.nnnOBJECTIVEnThe purpose of this study was to examine the anatomical association of AF rotors with LA and right atrial (RA) LGE on cardiac magnetic resonance.nnnMETHODSnThe cohort included 9 patients with persistent AF (mean age 61.1 ± 9.7 years) who underwent LGE cardiac magnetic resonance before AF ablation using the focal impulse and rotor modulation system. The extent of LA and RA LGE was quantified globally and in each of the 7 sectors: LA posterior/inferior wall, anterior wall, roof, left and right pulmonary vein antra, and RA lateral and septal regions. The multivariable association of rotor incidence with global and per sector LGE extent was examined using multivariable Bernoulli logistic regression estimated by generalized estimating equations.nnnRESULTSnThe mean RA and LA volumes were 113.2 ± 37.31 and 143.03 ± 58.25 mL, respectively. The mean RA and LA LGE burden was 17.2% ± 11.0% and 17.4% ± 14.4%, respectively. A total of 18 LA rotors and 9 RA rotors were identified in all patients. No univariable or multivariable association was observed between global or per sector LGE extent and focal impulse and rotor modulation rotor incidence.nnnCONCLUSIONnIn this cohort of patients, there was no association between AF rotor incidence and the global or regional extent of RA and LA LGE.