Ihab Diab

Maintenance of sinus rhythm with an ablation strategy in patients with atrial fibrillation is associated with a lower risk of stroke and death

Objective To investigate whether catheter ablation of atrial fibrillation (AF) reduces stroke rate or mortality. Methods An international multicentre registry was compiled from seven centres in the UK and Australia for consecutive patients undergoing catheter ablation of AF. Long-term outcomes were compared with (1) a cohort with AF treated medically in the Euro Heart Survey, and (2) a hypothetical cohort without AF, age and gender matched to the general population. Analysis of stroke and death was carried out after the first procedure (including peri-procedural events) regardless of success, on an intention-to-treat basis. Results 1273 patients, aged 58±11 years, 56% paroxysmal AF, CHADS2 score 0.7±0.9, underwent 1.8±0.9 procedures. Major complications occurred in 5.4% of procedures, including stroke/TIA in 0.7%. Freedom from AF following the last procedure was 85% (76% off antiarrhythmic drugs) for paroxysmal AF, and 72% (60% off antiarrhythmic drugs) for persistent AF. During 3.1 (1.0–9.6) years from the first procedure, freedom from AF predicted stroke-free survival on multivariate analysis (HR=0.30, CI 0.16 to 0.55, p<0.001). Rates of stroke and death were significantly lower in this cohort (both 0.5% per patient-year) compared with those treated medically in the Euro Heart Survey (2.8% and 5.3%, respectively; p<0.0001). Rates of stroke and death were no different from those of the general population (0.4% and 1.0%, respectively). Conclusion Restoration of sinus rhythm by catheter ablation of AF is associated with lower rates of stroke and death compared with patients treated medically.

A Randomized Controlled Trial of Catheter Ablation Versus Medical Treatment of Atrial Fibrillation in Heart Failure (The CAMTAF Trial)

Background—Restoring sinus rhythm in patients with heart failure (HF) and atrial fibrillation (AF) may improve left ventricular (LV) function and HF symptoms. We sought to compare the effect of a catheter ablation strategy with that of a medical rate control strategy in patients with persistent AF and HF. Methods and Results—Patients with persistent AF, symptomatic HF, and LV ejection fraction <50% were randomized to catheter ablation or medical rate control. The primary end-point was the difference between groups in LV ejection fraction at 6 months. Baseline LV ejection fraction was 32±8% in the ablation group and 34±12% in the medical group. Twenty-six patients underwent catheter ablation, and 24 patients were rate controlled. Freedom from AF was achieved in 21/26 (81%) at 6 months off antiarrhythmic drugs. LV ejection fraction at 6 months in the ablation group was 40±12% compared with 31±13% in the rate control group (P=0.015). Ablation was associated with better peak oxygen consumption (22±6 versus 18±6 mL/kg per minute; P=0.014) and Minnesota living with HF questionnaire score (24±22 versus 47±22; P=0.001) compared with rate control. Conclusions—Catheter ablation is effective in restoring sinus rhythm in selected patients with persistent AF and HF, and can improve LV function, functional capacity, and HF symptoms compared with rate control. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT01411371

Characterization of fractionated atrial electrograms critical for maintenance of atrial fibrillation: a randomized, controlled trial of ablation strategies (the CFAE AF trial).

Background— Whether ablation of complex fractionated atrial electrograms (CFAE) modifies atrial fibrillation (AF) by eliminating drivers or atrial debulking remains unknown. This randomized study aimed to determine the effect of ablating different CFAE morphologies compared with normal electrograms (ie, debulking normal tissue) on the cycle length of persistent AF (AFCL). Methods and Results— After pulmonary vein isolation left and right atrial CFAE were targeted, until termination of AF or abolition of CFAE before DC cardioversion. Ten-second electrograms were classified according to a validated scale, with grade 1 being most fractionated and grade 5 normal. Patients were randomly assigned to have CFAE grades eliminated sequentially, from grade 1 to 5 (group 1) or grade 5 to 1 (group 2). An increase in AFCL (mean of left and right atrial appendage) ≥5 ms after a lesion was regarded as significant. CFAE (n=968) were targeted in 20 patients. AFCL increased after targeting 51±35% of grade 1 CFAE, 30±15% grade 2, 12±5% grade 3, 33±12% grade 4, and 8±15% grade 5 CFAE ( P <0.01 for grades 1, 2, and 4 versus 5; 3 versus 5, not significant). The proportion of lesions causing AFCL prolongation was unaffected by the order in which CFAE were targeted. Conclusions— Targeting CFAE is not simply atrial debulking. Ablating certain grades of CFAE increases AFCL, suggesting they are more important in maintaining AF. Clinical Trial Registration— URL: . Unique identifier: [NCT00894400][1]. [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00894400&atom=%2Fcircae%2F4%2F5%2F622.atomBackground— Whether ablation of complex fractionated atrial electrograms (CFAE) modifies atrial fibrillation (AF) by eliminating drivers or atrial debulking remains unknown. This randomized study aimed to determine the effect of ablating different CFAE morphologies compared with normal electrograms (ie, debulking normal tissue) on the cycle length of persistent AF (AFCL). Methods and Results— After pulmonary vein isolation left and right atrial CFAE were targeted, until termination of AF or abolition of CFAE before DC cardioversion. Ten-second electrograms were classified according to a validated scale, with grade 1 being most fractionated and grade 5 normal. Patients were randomly assigned to have CFAE grades eliminated sequentially, from grade 1 to 5 (group 1) or grade 5 to 1 (group 2). An increase in AFCL (mean of left and right atrial appendage) ≥5 ms after a lesion was regarded as significant. CFAE (n=968) were targeted in 20 patients. AFCL increased after targeting 51±35% of grade 1 CFAE, 30±15% grade 2, 12±5% grade 3, 33±12% grade 4, and 8±15% grade 5 CFAE (P<0.01 for grades 1, 2, and 4 versus 5; 3 versus 5, not significant). The proportion of lesions causing AFCL prolongation was unaffected by the order in which CFAE were targeted. Conclusions— Targeting CFAE is not simply atrial debulking. Ablating certain grades of CFAE increases AFCL, suggesting they are more important in maintaining AF. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00894400.

Impact of variant pulmonary vein anatomy and image integration on long-term outcome after catheter ablation for atrial fibrillation.

AIMS To investigate the impact of variant pulmonary vein (PV) anatomy and the use of three-dimensional image integration (3D-II) on long-term efficacy of catheter ablation for atrial fibrillation (AF). METHODS Consecutive procedures from 2002 to 2007 were analysed from a prospective database. All patients underwent wide area circumferential ablation, with linear lesions added and complex fractionated electrograms targeted for persistent AF. Imaging was segmented on Carto to assess PV anatomy. RESULTS Three hundred and fifty patients underwent 1.9 ± 0.9 procedures. The mean age was 57 ± 11 years, 73% males, and 55% paroxysmal AF. Freedom from AF/atrial tachycardia was 42% for paroxysmal AF and 20% for persistent AF at 3.1 years after the first procedure, or 86 and 66%, respectively, at 2.5 years after the last procedure. The Kaplan-Meier analysis showed a trend towards improved single-procedure efficacy with 3D-II (8.9% difference, P = 0.087) and a reduction in the number of procedures per patient from 2.1 ± 1.1 to 1.8 ± 0.9 (P < 0.0001). The use of 3D-II improved single-procedure efficacy with Carto (13.3% difference, P = 0.018), but not with Ensite NavX. Variant PV anatomy was identified in 28% and was associated with a lower single-procedure efficacy (10.0% difference, P = 0.024) but with no effect on final outcome. Multivariate analysis confirmed the impact of 3D-II [hazard ratio (HR) for recurrence of AF 0.67, P = 0.020] and variant PV anatomy (HR 1.37, P = 0.044). CONCLUSION The use of 3D-II improves single-procedure efficacy of PV isolation for AF. Variant PV anatomy was associated with a lower single-procedure success rate.

Does ventricular dyssynchrony on echocardiography predict response to cardiac resynchronisation therapy? A randomised controlled study

Objective To determine the value of echocardiography in predicting response to cardiac resynchronisation therapy (CRT). Methods This is a prospective randomised study that recruited patients with (group 1) and without (group 2) echocardiographic evidence of mechanical dyssynchrony. 73 heart failure patients (NYHA III–IV) with a requirement for an implantable cardioverter defibrillator, QRS ≥120 ms and LV ejection fraction (EF) <35% were studied. Group 1 patients received CRT-D (26 patients). Group 2 patients were randomised to CRT-D (group 2a: 23 patients) or implantable cardioverter defibrillator (group 2b: 21 patients). Main outcome measures were peak oxygen consumption (VO2max), NYHA class, and echocardiography at baseline and at 6 months. Results 62% of group 1 patients achieved ≥1 ml/kg/min increase in VO2max at 6 months versus 50% in group 2a and 21% in group 2b (p=0.04). Group 1 patients showed significant improvements in VO2max (15.8±2 to 18.0±4 ml/kg/min, p=0.01), NYHA class (3.1±0.3 to 1.9±0.7, p<0.001) and EF (22±7% to 26±9%, p=0.02). Group 2a showed significant improvement in NYHA class (3.1±0.3 to 2.2±0.7, p<0.001) but no change in EF or VO2max. Group 2b showed no change in NYHA class or EF with a decline in VO2max (16.4±4 to 14.1±4, p=0.03). A significantly higher proportion of patients in group 2b showed ≥1 ml/kg/min deterioration in VO2max compared to group 2a (68% vs 23%, HR for group 2b: 2.4, 95% CI 1.2 to 4.8, p=0.005). Conclusions The presence of echocardiographic dyssynchrony identifies patients who derive the most improvement from CRT. Patients without dyssynchrony also show more benefit and less deterioration with CRT than without and should not be denied CRT.

A highly effective technique for transseptal endocardial left ventricular lead placement for delivery of cardiac resynchronization therapy

BACKGROUND Implantation of a left ventricular (LV) lead fails in 5% to 10% of patients in whom cardiac resynchronization therapy (CRT) is attempted. Alternatives for delivery of CRT are surgical epicardial and endocardial transvenous leads. Endocardial transseptal LV lead delivery is challenging because of the absence of dedicated equipment designed for this procedure. OBJECTIVE The purpose of this study was to describe a new technique for delivery of a transseptal LV lead. METHODS This dual approach from the right femoral vein and left subclavian vein involves use of an Endrys transseptal needle and Mullins sheath to deliver a gooseneck snare from the left subclavian vein into the right atrium that can then be used to deliver a deflectable sheath into the left atrium. An active fixation lead is advanced into the LV through the sheath and screwed into the lateral wall. RESULTS The procedure was performed successfully in 12 patients in whom transvenous LV lead implantation had previously failed. The Endrys transseptal needle, ideally suited for this technique, facilitated passage of the gooseneck snare into the left atrium with no difficulty. Median procedure time was 148 minutes (interquartile range [IQR] 113-176 minutes), and median fluoroscopy time was 16 minutes (IQR 10-19 minutes). There was no need for repeat procedures after median follow-up of 97 days (IQR 36-313 days). CONCLUSION This approach using an Endrys needle and a gooseneck snare provides a reliable and effective alternative technique for delivery of an endocardial LV lead that is delivered easily through a deflectable sheath inserted transseptally into the LV.

Predictors of new onset atrial fibrillation in patients with heart failure

INTRODUCTION Stroke associated with atrial fibrillation (AF) is more frequent in heart failure. It is unknown what variables predict future AF in these patients and how AF might evolve over time. We investigated this in patients with implantable cardiac defibrillators (ICD) where AF detection is optimal. METHODS Single centre, retrospective, observational cohort study. All ischaemic cardiomyopathy patients with dual chamber, primary prevention ICD implants between Aug 2003 and Dec 2009 were screened and included if at implant, they had no known AF history. Nine variables were analysed. AF was defined as any atrial tachyarrhythmia ≥180 bpm and ≥30 s. Multivariable, binary logistic regression models were built by adding variables significant in the univariate models. Variables were retained in the final multivariate models if p<0.05. RESULTS n=197 met the inclusion criteria (85.8% male, median age: 66.8 years). After median follow-up for 2.8 years, 44.2% developed AF. After univariate analysis, the baseline variables associated with AF after implant were age, NYHA class and renal impairment (RI, defined eGFR<60 ml/min/1.73 m2) (p<0.05). After multivariable analysis, the only variable which was associated with AF was RI (HR: 2.04 (CI: 1.10-3.79)). Two baseline variables were independently associated with all-cause mortality: RI (HR: 2.42 (1.14-5.12)) and non-white ethnicity. CONCLUSION RI at time of implant was independently associated with both future AF and all-cause mortality during long-term follow-up. RI was a stronger predictor of AF than age. Those patients with heart failure and RI should be regularly screened for asymptomatic AF, regardless of age, to ensure that stroke prophylaxis may be initiated.

The lung impedance monitoring in treatment of chronic heart failure (the LIMIT-CHF study).

AIMS To assess the usefulness of intrathoracic impedance monitoring (IIM) alerts in guiding empirical treatment of chronic heart failure (CHF) patients to prevent heart failure (HF) hospitalizations and unplanned HF care. METHODS AND RESULTS Chronic heart failure patients with OptiVol or CorVue capable implantable cardioverter-defibrillators were randomized to either the active group (IIM alarm turned on and diuretic dose increased by 50% for 1 week in the event of alarm sounding) or the control group (IIM alarm turned off). The primary endpoint was the number of HF hospitalizations per patient at 1 year. The NYHA class, 6MWT, B-type natriuretic peptide (BNP), and MLWHF questionnaire score were collected at baseline and follow-up. Eighty patients were included and 71 reached 1-year follow-up. There were 1.7 ± 1.5 alerts in the active group and 1.1 ± 1.0 in the control group, P = 0.07. In the active group, 61% of alerts led to a diuretic dose increase. There was a total of 11 HF hospitalizations in the active group vs. 6 in the control group without significant differences in the number of episodes per patient (0.3 ± 0.9 vs. 0.2 ± 0.4, P = 0.95). There were no unplanned HF visits in the active group vs. 0.1 ± 0.3 per patient in the control group, P = 0.08. The total MLWHF scores were significantly increased at the final follow-up in the control group, whereas a trend towards reduction was observed in the active group. CONCLUSION In this study, an empirical HF treatment guided by IIM alerts did not reduce emergency treatment of HF. However, it seems to have a positive impact on quality of life. CLINICAL TRIAL REGISTRATIONURL: http://www.clinicaltrials.gov. Unique identifier: NCT01320007.

Characterization of Fractionated Atrial Electrograms Critical for Maintenance of Atrial FibrillationClinical Perspective: A Randomized, Controlled Trial of Ablation Strategies (The CFAE AF Trial)

Background— Whether ablation of complex fractionated atrial electrograms (CFAE) modifies atrial fibrillation (AF) by eliminating drivers or atrial debulking remains unknown. This randomized study aimed to determine the effect of ablating different CFAE morphologies compared with normal electrograms (ie, debulking normal tissue) on the cycle length of persistent AF (AFCL). Methods and Results— After pulmonary vein isolation left and right atrial CFAE were targeted, until termination of AF or abolition of CFAE before DC cardioversion. Ten-second electrograms were classified according to a validated scale, with grade 1 being most fractionated and grade 5 normal. Patients were randomly assigned to have CFAE grades eliminated sequentially, from grade 1 to 5 (group 1) or grade 5 to 1 (group 2). An increase in AFCL (mean of left and right atrial appendage) ≥5 ms after a lesion was regarded as significant. CFAE (n=968) were targeted in 20 patients. AFCL increased after targeting 51±35% of grade 1 CFAE, 30±15% grade 2, 12±5% grade 3, 33±12% grade 4, and 8±15% grade 5 CFAE ( P <0.01 for grades 1, 2, and 4 versus 5; 3 versus 5, not significant). The proportion of lesions causing AFCL prolongation was unaffected by the order in which CFAE were targeted. Conclusions— Targeting CFAE is not simply atrial debulking. Ablating certain grades of CFAE increases AFCL, suggesting they are more important in maintaining AF. Clinical Trial Registration— URL: . Unique identifier: [NCT00894400][1]. [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00894400&atom=%2Fcircae%2F4%2F5%2F622.atomBackground— Whether ablation of complex fractionated atrial electrograms (CFAE) modifies atrial fibrillation (AF) by eliminating drivers or atrial debulking remains unknown. This randomized study aimed to determine the effect of ablating different CFAE morphologies compared with normal electrograms (ie, debulking normal tissue) on the cycle length of persistent AF (AFCL). Methods and Results— After pulmonary vein isolation left and right atrial CFAE were targeted, until termination of AF or abolition of CFAE before DC cardioversion. Ten-second electrograms were classified according to a validated scale, with grade 1 being most fractionated and grade 5 normal. Patients were randomly assigned to have CFAE grades eliminated sequentially, from grade 1 to 5 (group 1) or grade 5 to 1 (group 2). An increase in AFCL (mean of left and right atrial appendage) ≥5 ms after a lesion was regarded as significant. CFAE (n=968) were targeted in 20 patients. AFCL increased after targeting 51±35% of grade 1 CFAE, 30±15% grade 2, 12±5% grade 3, 33±12% grade 4, and 8±15% grade 5 CFAE (P<0.01 for grades 1, 2, and 4 versus 5; 3 versus 5, not significant). The proportion of lesions causing AFCL prolongation was unaffected by the order in which CFAE were targeted. Conclusions— Targeting CFAE is not simply atrial debulking. Ablating certain grades of CFAE increases AFCL, suggesting they are more important in maintaining AF. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00894400.

Diagnostic yield of cardiovascular magnetic resonance in young-middle aged patients with high-grade atrio-ventricular block

BACKGROUND Atrio-ventricular block (AVB) is a rare finding in young or middle-aged adults, often leading to pacemaker implantation (PM) without further investigation. We sought to assess the diagnostic role of cardiovascular magnetic resonance (CMR) in young and middle-aged adults with high-grade AVB. METHODS We consecutively enrolled young-middle aged (18-65years) patients with high grade AVB referred to CMR after standard clinical assessment (history, electrocardiogram and cardiac rhythm monitoring) prior to PM implantation. Cine and post-contrast imaging were performed in a 1.5T scanner. RESULTS 34 patients (59% male, mean age 42±12years) with high grade AVB were referred to CMR for suspected ischemic heart disease (IHD)(n=4) and non-ischemic heart disease (NIHD)(n=20); no clear cause was found in 9 patients prior to CMR and 1 patient had suspected lung disease. A pathologic substrate was found on CMR in 15 patients (44%), while a structurally normal heart was reported in 18 (53%). Non-specific findings were reported in 1 patient (3%). There was a fair agreement between CMR and echocardiographic findings (Cohens kappa 0.243), and CMR provided an entirely new diagnosis in 34% of patients. As compared to the standard clinical assessment, CMR had an additional role in 65% of patients and guided further testing (genetic testing, extra-cardiac imaging) in 9%. CONCLUSIONS CMR found a pathologic substrate in 44% of patients, mainly NIHD (32%). Half of the patients (53%) had a structurally normal heart. When added to the standard clinical assessment, CMR had an incremental diagnostic role in two thirds of patients.