Bryan Baranowski

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.

Natural History and Long-Term Outcomes of Ablated Atrial Fibrillation

Background—Atrial fibrillation (AF) ablation is increasingly used in clinical practice. We aimed to study the natural history and long-term outcomes of ablated AF. Methods and Results—We followed 831 patients after pulmonary vein isolation (PVI) performed in 2005. We documented clinical outcomes using our prospective AF registry with most recent update on this group of patients in October 2009. In the first year after ablation, 23.8% had early recurrence. Over long-term follow-up (55 months), only 8.9% had late arrhythmia recurrence defined as occurring beyond the first year after ablation. Repeat ablations in patients with late recurrence revealed conduction recovery in at least 1 of the previously isolated PVs in all of them and right-sided triggers with isoproterenol testing in 55.6%. At last follow-up, clinical improvement was 89.9% (79.4% arrhythmia-free off antiarrhythmic drugs and 10.5% with AF controlled with antiarrhythmic drugs). Only 4.6% continued to have drug-resistant AF. It was possible to safely discontinue anticoagulation in a substantial proportion of patients with no recurrence in the year after ablation (CHADS score ⩽2, stroke incidence of 0.06% per year). The procedure-related complication rate was very low. Conclusions—Pulmonary vein isolation is safe and efficacious for long-term maintenance of sinus rhythm and control of symptoms in patients with drug-resistant AF. It obviates the need for antiarrhythmic drugs, negative dromotropic agents, and anticoagulants in a substantial proportion of patients.

Characterization of super-response to cardiac resynchronization therapy.

BACKGROUND In 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. OBJECTIVE The purpose of this study was to identify baseline clinical attributes of super-responders and to assess the survival benefit associated with this response. METHODS We 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. RESULTS In 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. CONCLUSION Baseline 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.

Clinical predictors of adverse patient outcomes in an experience of more than 5000 chronic endovascular pacemaker and defibrillator lead extractions

BACKGROUND It is difficult to predict adverse patient outcomes associated with transvenous lead extraction (TLE) procedures. OBJECTIVE The purpose of this study was to examine the safety and efficacy of chronic endovascular pacemaker and implantable cardioverter-defibrillator (ICD) lead extraction and risk factors associated with adverse patient outcomes. METHODS Consecutive patients undergoing TLE at the Cleveland Clinic between August 1996 and August 2011 were included in the analysis. Univariate and multivariable logistic regression analyses were performed to evaluate for associations with outcomes. Continuous data are given as median (25th, 75th percentile). Categorical data are given as number (percentage). RESULTS In total, 5521 leads (4137 [74.9%] pacemaker, 1384 [25.1%] ICD) were extracted during 2999 TLE procedures (patient age 67.2 [55.2, 76.2] years, 30.2% female). Lead implant duration was 4.7 (2.4, 8.3) years, and 2.0 (1.0, 2.0) leads were extracted per procedure. Powered sheaths were used in 74.9% of procedures. Overall, there was 95.1% complete procedural success, 98.9% clinical success, and 1.1% failure, with 3.6% minor complications and 1.8% major complications. All-cause mortality within 30 days of TLE was 2.2%. Multivariable predictors of major complications included cerebrovascular disease, ejection fraction ≤15%, lower platelet count, international normalized ratio ≥1.2, mechanical sheaths, and powered sheaths. Multivariable predictors of all-cause mortality within 30 days of TLE included body mass index <25 kg/m(2), end-stage renal disease, higher New York Heart Association functional class, lower hemoglobin, higher international normalized ratio, lead extraction for infection, and extraction of a dual-coil ICD lead. CONCLUSION TLE in this single-center experience was highly successful. Risk factors associated with adverse patient outcomes were identified.

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

OBJECTIVES The 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. BACKGROUND At 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. METHODS We 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. RESULTS A 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). CONCLUSIONS QRS morphology is a more important baseline electrocardiographic determinant of CRT response than QRSd.

Plasma B-Type Natriuretic Peptide Levels and Recurrent Arrhythmia After Successful Ablation of Lone Atrial Fibrillation

Background— Plasma B-type natriuretic peptide (BNP) is abnormally elevated in patients with lone atrial fibrillation (AF). The exact significance and prognostic implications of this elevation have yet to be determined. Little is known about BNP in lone AF patients undergoing arrhythmia ablation. We sought to determine the relationship between BNP levels and the risk of recurrent arrhythmia after ablation of lone AF. Methods and Results— We followed up 726 patients with lone AF undergoing first-time arrhythmia ablation. All had BNP levels measured on the day of ablation with of the point-of-care Triage Meter assay (Biosite Diagnostics, San Diego, CA). At baseline, factors associated with elevated BNP levels in multivariable linear regression analysis (with log BNP being the dependent variable) were older age (&bgr; regression coefficient for +1-year change, 0.025; P<0.0001), longer duration of AF (&bgr; for +1-year change, 0.031; P=0.01), nonparoxysmal AF (versus paroxysmal; &bgr;, 0.52; P<0.0001), and larger left atrial size (&bgr; for +1-cm2 change, 0.040; P<0.0001). The BNP levels were strongly associated with arrhythmia recurrence in univariate- (hazard ratio for +1-log-BNP change, 2.32; 95% confidence interval, 2.11 to 2.74; P<0.001) and covariate- (hazard ratio for +1-log-BNP change, 2.13; 95% confidence interval, 2.06 to 2.38; P<0.001) adjusted Cox proportional hazards analysis. The covariate-adjusted hazard ratios for recurrent arrhythmia were 1.6, 2.7, 4.3, and 5.7 for the second, third, fourth, and fifth quintiles, respectively, compared with patients in the lowest quintile (P for trend across quintiles <0.001). Conclusions— B-type natriuretic peptide levels correlate with AF burden (chronicity, altered hemodynamics, and anatomic remodeling) in patients with lone AF and are strong predictors of recurrent arrhythmia after ablation. Elevated BNP levels may reflect increased cardiac chamber wall stress and/or intrinsic atrial disease, thus increasing the risk of arrhythmia recurrence.

Outcomes of patients requiring emergent surgical or endovascular intervention for catastrophic complications during transvenous lead extraction

BACKGROUND The outcomes of patients requiring emergent surgical or endovascular intervention during transvenous lead extraction (TLE) have not been well characterized. OBJECTIVES To evaluate the incidence of catastrophic complications requiring emergent surgical or endovascular intervention during TLE, to describe the injuries, and to review patient management and outcomes. METHODS Consecutive patients undergoing TLE of pacemaker and implantable cardioverter-defibrillator (ICD) leads at the Cleveland Clinic between August 1996 and September 2012 were included in the analysis. RESULTS A total of 5973 (4436 [74.3%] pacemaker and 1537 [25.7%] ICD) leads were extracted during 3258 TLE procedures (median [25th, 75th percentile] patient age 67.0 [55.0, 76.1] years; 69.2% men). The median (25th, 75th percentile) lead implant duration was 4.9 (2.4, 8.4) years, and 2.0 (1.0, 2.0) leads were extracted per procedure. Powered sheaths were used in 2369 (72.7%) procedures. Twenty-five (0.8%) patients experienced catastrophic complications requiring emergent surgical or endovascular intervention. Twenty patients (0.6%) required either sternotomy (n = 18) or thoracotomy (n = 2) for superior vena cava laceration (n = 15) and right atrial (n = 2) or ventricular (n = 3) perforation. Two patients required vascular repair at the procedural access site for either subclavian vein or artery laceration. Three patients were managed with an endovascular approach for superior vena cava laceration, left axillary artery laceration, and brachiocephalic vein and artery fistula. In-hospital mortality was 36.0% (6 procedural/operative deaths and 3 deaths during the same hospitalization). CONCLUSIONS Major vascular injury or cardiac perforation requiring emergent surgical or endovascular intervention during TLE is uncommon but carries significant in-hospital mortality. Despite high mortality, nearly two-thirds of these patients were rescued with immediate response and surgical or endovascular intervention.

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

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

Transvenous extraction of implantable cardioverter-defibrillator leads under advisory—A comparison of Riata, Sprint Fidelis, and non-recalled implantable cardioverter-defibrillator leads

BACKGROUND Comparative safety and efficacy associated with transvenous lead extraction (TLE) of recalled and non-recalled implantable cardioverter-defibrillator (ICD) leads has not been well characterized. OBJECTIVES To compare the indications, techniques, and procedural outcomes of recalled vs non-recalled ICD lead extraction procedures. METHODS TLE procedures performed at our institution from June 2002 to June 2012 in which Riata, Sprint Fidelis, or non-recalled ICD leads were extracted were included in the analysis. RESULTS ICD lead extraction procedures were performed in 1079 patients, including 430 patients with recalled leads (121 Riata, 308 Sprint Fidelis, and 1 Riata and Sprint Fidelis) and 649 patients with non-recalled ICD leads. A total of 2056 chronic endovascular leads were extracted, of which 1215 (59.1%) were ICD leads. Overall, there was 96.8% complete procedural success, 99.1% clinical success, and 0.9% failure, with 3.9% minor complications and 1.5% major complications. Procedural outcomes for Riata and Sprint Fidelis TLE procedures were no different. Lead implant duration was significantly less in recalled than in non-recalled ICD lead TLE procedures. Complete procedural success was higher in recalled (424 of 430 [98.6%]) than in non-recalled (621 of 649 [95.7%]; P = .007) ICD lead TLE procedures. Minor complications were lower in recalled (10 of 430 [2.3%]) than in non-recalled (32 of 649 [5.0%]; P = .030) ICD lead TLE procedures. Rates of clinical success, failure, and major complications were no different in the recalled and non-recalled ICD lead TLE procedures. CONCLUSION In our experience, recalled ICD leads were extracted with safety and efficacy comparable to that of non-recalled ICD leads.

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.