Predictors and treatment response with cardiac resynchronization therapy in patients with heart failure characterized by dyssynchrony: a pre-defined analysis from the CARE-HF trial. Surface electrocardiogram to predict outcome in candidates for cardiac resynchronization therapy: a sub-analysis of the CARE-HF trial. Response to cardiac resynchronization therapy in elderly patients (≥70 years) and octogenarians Cardiac-resynchronization therapy in heart failure with narrow QRS complexes. Cardiac Sympathetic Reserve and Response to Cardiac Resynchronization Therapy Randomized trial of cardiac resynchronization in mildly symptomatic heart failure patients and in asymptomatic patients with left ventricular dysfunction and previous heart failure symptoms. Long‐term mortality with cardiac resynchronization therapy in the Cardiac Resynchronization‐Heart Failure (CARE‐HF) trial Outcomes of cardiac resynchronization therapy in patients with intermittent atrial fibrillation or atrial flutter in the COMPANION trial. Cardiac resynchronization therapy for the treatment of heart failure in patients with intraventricular conduction delay and malignant ventricular tachyarrhythmias. Comparative long-term outcomes after cardiac resynchronization therapy in right ventricular paced patients versus native wide left bundle branch block patients. Rationale and design of the BUDAPEST-CRT Upgrade Study: a prospective, randomized, multicentre clinical trial The European cardiac resynchronization therapy survey. Time course of effects of cardiac resynchronization therapy in chronic heart failure: benefits in patients with preserved exercise capacity. Cardiac resynchronization therapy improves renal function in human heart failure with reduced glomerular filtration rate. Monitoring of physical activity and heart rate variability in patients with chronic heart failure using cardiac resynchronization devices. Comparison of usefulness of cardiac resynchronization therapy in patients with atrial fibrillation and heart failure versus patients with sinus rhythm and heart failure. Improvement of congestive heart failure by upgrading of conventional to resynchronization pacemakers.
AIMS The cardiac resynchronization therapy in heart failure trial ( CARE-HF ) demonstrated that cardiac resynchronization therapy ( CRT ) reduces morbidity and mortality in patients with heart failure and cardiac dyssynchrony . The aim of this study was to develop a prognostic model to evaluate the relationship between prospect ively defined patient characteristics and treatment on the trial primary outcome of death from any cause or unplanned hospitalization for a major cardiovascular event . METHODS AND RESULTS A total of 813 patients were enrolled in the CARE-HF study and were followed for a mean of 29.4 months . A Cox Proportional Hazards Model was fitted to identify predictors of the primary outcome and any predictors that modified the effect of CRT . Ischaemic aetiology , more severe mitral regurgitation and increased N-terminal pro-brain natriuretic peptide , were associated with an increased risk of death or unplanned cardiovascular hospitalization irrespective of cardiac resynchronization [ Hazard ratio ( HR ) 1.89 , 95 % CI 1.45 - 2.46 , HR 1.71 , 95 % CI 1.38 - 2.12 and HR 1.31 , 95 % CI 1.17 - 1.47 , respectively ] and increasing systolic blood pressure with a decreasing risk of an event ( HR 0.99 , 95 % CI 0.98 - 1.00 ) . The benefits of cardiac resynchronization were modified by systolic blood pressure and interventricular mechanical delay ( IVMD ) . Patients with increasing systolic blood pressure appear to receive reduced benefit from CRT ( HR 1.02 , 95 % CI 1.00 - 1.03 ) , whereas those patients with more severe IVMD appear to benefit more from treatment ( HR 0.99 , 95 % CI 0.98 - 1.00 ) . CONCLUSION Patients with echocardiographic evidence of more severe cardiac dyssynchrony and low systolic blood pressure obtain greater benefit from CRT , although benefits were substantial across the range of subjects included in the trial AIMS In CARE-HF , cardiac resynchronization therapy ( CRT ) lowered morbidity and mortality in patients with moderate to severe heart failure . We examined whether baseline and follow-up electrocardiographic characteristics might predict long-term outcome . METHODS AND RESULTS CARE-HF r and omly assigned 409 patients to medical therapy ( MT ) plus CRT , and 404 patients to MT alone .  Electrocardiographic measurements were made at baseline during sinus rhythm , and at 3 months during paced or spontaneous rhythm depending on treatment assignment . Favourable outcome was defined as freedom from death , urgent transplantation , or cardiovascular hospitalization . Among patients assigned to CRT , 39 % had unfavourable outcomes including 55 deaths . By single variable analysis , ( i ) prolonged PR interval , left QRS axis ( but not QRS duration ) , and left bundle branch block ( BBB ) at baseline , and ( ii ) heart rate , PR , and QRS duration at 3 months predicted unfavourable outcome . By multiple variable analysis , treatment assignment ( P = 0.0001 ) , PR ( P = 0.0004 ) , and right BBB ( P < 0.00013 ) at baseline predicted outcome , whereas baseline JTc and QRS duration at 3 months predicted all-cause mortality and heart failure hospitalization ( P = 0.0071 ) . CONCLUSION In CARE-HF , QRS duration at baseline did not predict outcome , but QRS at 3 months was a predictor by single variable analysis . Patients with prolonged PR interval and the 5 % of patients with right BBB had a particularly high event rate Cardiac resynchronization therapy ( CRT ) leads to reverse ventricular remodelling , improved functional capacity , and better clinical outcome in patients with advanced chronic heart failure , reduced ejection fraction , and evidence of ventricular conduction delay , who are under optimal medical therapy . This study investigated whether these benefits can be extrapolated to older patients , typically not included in r and omized clinical trials BACKGROUND Indications for cardiac-resynchronization therapy ( CRT ) in patients with heart failure include a prolonged QRS interval ( > or = 120 msec ) , in addition to other functional criteria . Some patients with narrow QRS complexes have echocardiographic evidence of left ventricular mechanical dyssynchrony and may also benefit from CRT . METHODS We enrolled 172 patients who had a st and ard indication for an implantable cardioverter-defibrillator . Patients received the CRT device and were r and omly assigned to the CRT group or to a control group ( no CRT ) for 6 months . The primary end point was the proportion of patients with an increase in peak oxygen consumption of at least 1.0 ml per kilogram of body weight per minute during cardiopulmonary exercise testing at 6 months . RESULTS At 6 months , the CRT group and the control group did not differ significantly in the proportion of patients with the primary end point ( 46 % and 41 % , respectively ) . In a prespecified subgroup with a QRS interval of 120 msec or more , the peak oxygen consumption increased in the CRT group ( P=0.02 ) , but it was unchanged in a subgroup with a QRS interval of less than 120 msec ( P=0.45 ) . There were 24 heart-failure events requiring intravenous therapy in 14 patients in the CRT group ( 16.1 % ) and 41 events in 19 patients in the control group ( 22.3 % ) , but the difference was not significant . CONCLUSIONS CRT did not improve peak oxygen consumption in patients with moderate-to-severe heart failure , providing evidence that patients with heart failure and narrow QRS intervals may not benefit from CRT . ( Clinical Trials.gov number , NCT00132977 [ Clinical Trials.gov ] . ) Background — The objective of the present study was to investigate the effect of cardiac resynchronization therapy ( CRT ) on cardiac autonomic function . Methods and Results — This prospect i ve study included 45 consecutive patients with heart failure who received CRT devices with defibrillator and 20 age-matched , healthy control subjects . At baseline and 3 months and 6 months after CRT , we assessed New York Heart Association ( NYHA ) class , 6-minute walk distance , plasma sympathetic biomarker nerve growth factor , echocardiography , heart rate variability and cardiac presynaptic sympathetic function determined by  iodine 123 metaiodobenzylguanidine scintigraphy . After CRT , NYHA class improved by 1 class ( P<0.001 ) , and left ventricular ejection fraction increased by 8 % ( P<0.001 ) . Along with improvement in the st and ard deviation of all normal-to-normal R-R intervals ( 85.63±31.66 ms versus 114.79±38.99 ms ; P=0.004 ) and the st and ard deviation of the averaged normal-to-normal R-R intervals ( 82.62±23.03 ms versus 100.50±34.87 ms ; P=0.004 ) , the delayed heart/mediastinum ( H/M ) ratio increased ( 1.82 [ 0.58 ] versus 1.97 [ 0.59 ] ; P=0.03 ) , whereas the mean ( SD ) H/M washout rate was reduced ( 48 % [ 19 % ] versus 37 % [ 22 % ] ; P=0.01 ) . Twenty-two of 45 study patients responded to CRT , with a reduction of left ventricular end-systolic volume index > 15 % . Compared with nonresponders , responders had a higher delayed H/M ratio ( 2.11 versus 1.48 ; P=0.003 ) and lower H/M washout rate ( 37 % versus 62 % ; P=0.003 ) at baseline . Conclusions — CRT  improved sympathetic function . Cardiac sympathetic reserve may be a marker for the reversibility of failing myocardial function OBJECTIVES We sought to determine the effects of cardiac resynchronization therapy ( CRT ) in New York Heart Association ( NYHA ) functional class II heart failure ( HF ) and NYHA functional class I ( American College of Cardiology/American Heart Association stage C ) patients with previous HF symptoms . BACKGROUND Cardiac resynchronization therapy improves left ventricular ( LV ) structure and function and clinical outcomes in NYHA functional class III and IV HF with prolonged QRS . METHODS Six hundred ten patients with NYHA functional class I or II heart failure with a QRS > or = 120 ms and a LV ejection fraction < or = 40 % received a CRT device ( + /-defibrillator )  and were r and omly assigned to active CRT ( CRT-ON ; n = 419 ) or control ( CRT-OFF ; n = 191 ) for 12 months . The primary end point was the HF clinical composite response , which scores patients as improved , unchanged , or worsened . The prospect ively powered secondary end point was LV end-systolic volume index . Hospitalization for worsening HF was evaluated in a prospect i ve secondary analysis of health care use . RESULTS The HF clinical composite response end point , which compared only the percent worsened , indicated 16 % worsened in CRT-ON compared with 21 % in CRT-OFF ( p = 0.10 ) . Patients assigned to CRT-ON experienced a greater improvement in LV end-systolic volume index ( -18.4 + /- 29.5 ml/m2 vs. -1.3 + /- 23.4 ml/m2 , p < 0.0001 ) and other measures of LV remodeling . Time-to-first HF hospitalization was significantly delayed in CRT-ON ( hazard ratio : 0.47 , p = 0.03 ) . CONCLUSIONS The REVERSE ( REsynchronization reVErses Remodeling in Systolic left vEntricular dysfunction ) trial demonstrates that CRT , in combination with optimal medical therapy ( + /-defibrillator ) , reduces the risk for heart failure hospitalization and improves ventricular structure and function in NYHA functional class II and NYHA functional class I ( American College of Cardiology/American Heart Association stage C ) patients with previous HF symptoms . ( REsynchronization reVErses Remodeling in Systolic Left vEntricular Dysfunction [ REVERSE ] ; NCT00271154 ) The Cardiac Resynchronization‐Heart Failure ( CARE‐HF ) study helped establish an important role for cardiac resynchronization therapy ( CRT ) in the management of selected patients with heart failure . We now report the long‐term outcome during and subsequent to the r and omized trial BACKGROUND Controlled clinical trial data are lacking for cardiac resynchronization therapy ( CRT ) outcomes in patients with advanced heart failure ( HF ) from reduced left ventricular ejection fraction ( HFrEF ) and intermittent atrial fibrillation or flutter ( IAF/AFL ) . OBJECTIVE The purpose of this study was to describe CRT outcomes in patients with IAF/AFL and advanced HF . METHODS HF outcomes in patients in the COMPANION ( Comparison of Medical Therapy , Pacing , and Defibrillation in Heart Failure ) trial with New York Heart Association class III or IV HFrEF , left ventricular ejection fraction ≤0.35 , sinus rhythm at r and omization , and no history of baseline arrhythmia were compared with those with a history of IAF/AFL . RESULTS In those with no history of baseline arrhythmia ( n = 887 ) , compared with optimal pharmacological therapy ( OPT ) with no CRT , the CRT + OPT arms exhibited a significant reduction in the end points of death or any hospitalization ( hazard ratio [ HR ] 0.73 [ 95 % Confidence Interval ( CI ) : 0.60 to 0.89 ] ; P = .002 ) and death or HF hospitalization ( HR 0.53 [ 95 % CI : 0.41 to 0.68 ] ; P < .001 ) . In contrast , in the IAF/AFL subgroup ( n = 293 ) , CRT did not result in improved outcomes compared with OPT ( death or any hospitalization : HR 1.16 [ 95 % CI : 0.83 to 1.63 ] ; P = .38 ; death or HF hospitalization : HR 0.97 [ 95 % CI : 0.64 to 1.46 ] ; P = .88 ) . The interaction between history of AF/AFL and CRT was statistically significant for both outcomes ( P < .05 ) . CONCLUSION In the COMPANION trial , patients with moderate to severe HFrEF and a history of IAF/AFL had no benefit from CRT OBJECTIVES This study was conducted to assess the safety and effectiveness of cardiac resynchronization therapy ( CRT ) when combined with an implantable cardioverter defibrillator ( ICD ) . BACKGROUND Long-term outcome of CRT was measured in patients with symptomatic heart failure ( HF ) , intraventricular conduction delay , and malignant ventricular tachyarrhythmias ( ventricular tachycardia/ventricular fibrillation [ VT/VF ] ) requiring therapy from an ICD . METHODS Patients ( n = 490 ) were implanted with a device capable of providing both CRT and ICD therapy and r and omized to CRT ( n = 245 ) or control ( no CRT , n = 245 ) for up to six months . The primary end point was progression of HF , defined as all-cause mortality , hospitalization for HF , and VT/VF requiring device intervention . Secondary end points included peak oxygen consumption ( VO(2 ) ) , 6-min walk ( 6 MW ) , New York Heart Association ( NYHA ) class , quality of life ( QOL ) , and echocardiographic analysis . RESULTS A 15 % reduction in HF progression was observed , but this was statistically insignificant ( p = 0.35 ) . The CRT , however , significantly improved peak VO(2 ) ( 0.8 ml/kg/min vs. 0.0 ml/kg/min , p = 0.030 ) and 6 MW ( 35 m vs. 15 m , p = 0.043 ) . Changes in NYHA class ( p = 0.10 ) and QOL ( p = 0.40 ) were not statistically significant . The CRT demonstrated significant reductions in ventricular dimensions ( left ventricular internal diameter in diastole = -3.4 mm vs. -0.3 mm , p < 0.001 and left ventricular internal diameter in systole = -4.0 mm vs. -0.7 mm , p < 0.001 ) and improvement in left ventricular ejection fraction ( 5.1 % vs. 2.8 % , p = 0.020 ) . A subgroup of patients with advanced HF ( NYHA class III/IV ) consistently demonstrated improvement across all functional status end points . CONCLUSIONS The CRT improved functional status in patients indicated for an ICD who also have symptomatic HF and intraventricular conduction delay BACKGROUND The current guidelines do not clearly state when we should up grade a patient with right ventricular pacing ( RVP ) to cardiac resynchronization therapy ( CRT )  , although the deleterious effect of chronic RVP has been established with recent trials . OBJECTIVES The aims of this study were to compare the long-term survival after CRT in patients up grade d from RVP with that in patients with left bundle branch block ( LBBB ) with QRS duration ≥ 150 ms and to compare the mechanical properties associated with CRT response in these groups . METHODS Overall , 135 patients with implanted CRT from a single center ( 85 ( 63 % ) with native wide LBBB and 50 ( 37 % ) with RVP ) were studied prospect ively . Baseline left ventricular typical contraction pattern was determined using speckle tracking echocardiography in the apical 4-chamber view . The predefined end point was death , heart transplantation , or left ventricular assist device implantation over a period of 4 years . RESULTS Patients with RVP had a significantly favorable long-term outcomes with adjusted hazard ratio of 0.36 ( 95 % confidence interval 0.14 - 0.96 ; P = .04 ) . Both groups had ~70 % of patients with typical contraction pattern . The absence of typical contraction pattern was associated with a higher risk of an end point with adjusted hazard ratio of 5.43 ( 95 % confidence interval 2.31 - 12.72 ; P < .001 ) . In patients with typical contraction pattern , activation of the apical septal segment occurred more frequently in the RVP group and of the base or mid septal segments in the LBBB group . CONCLUSION Patients with HF up grade d from RVP have more favorable long-term outcomes  after CRT than do native LBBB patients with QRS duration ≥ 150 ms . Contraction pattern assessment can be used to identify potential responders in the RVP group Abstract Aims There is lack of conclusive evidence from r and omized clinical trials on the efficacy and safety of up grade to cardiac resynchronization therapy ( CRT ) in patients with implanted pacemakers ( PM ) or defibrillators ( ICD ) with reduced left ventricular ejection fraction ( LVEF ) and chronic heart failure ( HF ) . The BUDAPEST-CRT Up grade Study was design ed to compare the efficacy and safety of CRT up grade from conventional PM or ICD therapy in patients with intermittent or permanent right ventricular ( RV ) septal/apical pacing , reduced LVEF , and symptomatic HF . Methods and results The BUDAPEST-CRT study is a prospect i ve , r and omized , multicentre , investigator-sponsored clinical trial . A total of 360 subjects will be enrolled with LVEF ≤ 35 % , NYHA functional classes II – IVa , paced QRS ≥ 150 ms , and a RV pacing ≥ 20 % . Patients will be followed for 12 months . R and omization is performed in a 3:2 ratio ( CRT-D vs. ICD ) . The primary composite endpoint is all-cause mortality , a first HF event , or less than 15 % reduction in left ventricular ( LV ) end-systolic volume at 12 months . Secondary endpoints are all-cause mortality , all-cause mortality or HF event , and LV volume reduction at 12 months . Tertiary endpoints include changes in quality of life , NYHA functional class , 6 min walk test , natriuretic peptides , and safety outcomes . Conclusion The results of our prospect i ve , r and omized , multicentre clinical trial will provide important information on the role of cardiac resynchronization therapy with defibrillator ( CRT-D ) up grade in patients with symptomatic HF , reduced LVEF , and wide-paced QRS with intermittent or permanent RV pacing . Clinical trials.gov identifier NCT02270840 AIMS The European cardiac resynchronization therapy ( CRT ) survey is a joint initiative taken by the Heart Failure Association and the European Heart Rhythm Association of the European Society of Cardiology . The primary aim of this survey is to describe current European practice associated with CRT implantations . METHODS AND RESULTS A total of 140 centres from 13 European countries contributed data from consecutive patients successfully implanted with a CRT device with or without an ICD between November 2008 and June 2009 . The total number of patients enrolled was 2438 . The median age of the patients was 70 years ( IQR 62 - 76 ) and 31 % were > or = 75 years . It was found that 78 % were in NYHA functional class III or IV and 22 % in I or II . The mean ejection fraction was 27 % + /- 8 and the mean QRS duration 157 ms + /- 32 . The QRS duration was < 120 ms in 9 % . Atrial fibrillation was reported in 23 % . It was found that 26 % of patients had a previously implanted permanent pacemaker or ICD ; 76 % of procedures were performed by an electrophysiologist ; 82 % had an elective admission for implantation and the median duration of hospitalization was 3 days ( IQR 2 - 7 ) ; and 73 % received a CRT-D device which was more often implanted in men , younger patients , and with ischaemic aetiology . The mean QRS duration was reduced to 133 ms + /- 27 ( P < 0.0001 ) at discharge . Peri-procedural complication rates were comparable to the rates reported in r and omized trials . CONCLUSION This CRT survey provides important information describing current European practice with regard to patient demographics , selection criteria , procedural routines , and status at discharge . These data should be useful for benchmarking individual patient management and national practice against wider experience OBJECTIVES To assess in patients with chronic heart failure the effect of cardiac resynchronization therapy ( CRT ) over 12 months ' follow-up the time course of the changes in functional and neurohormonal indices and to identify responders to CRT . METHODS Eighty-nine patients ( 74.1 + /- 1 years , left ventricular ejection fraction [ LVEF ] < 35 % ) , QRS complex duration > 150 ms , in stable New York Heart Association ( NYHA ) class III or IV on optimal medical treatment were prospect ively r and omized either in a control ( n = 45 ) or CRT ( n = 44 ) group and underwent  clinical evaluation , cardiopulmonary exercise testing ( CPET ) , 2D-Echo , heart rate variability ( HRV ) , carotid baroreflex ( BRS ) , and BNP assessment s before and at 6- and 12-month follow-up . RESULTS In the CRT group , improvement of cardiac indices and BNP concentration were evident at medium term ( over 6 months ) follow-up , and these changes persisted on a longer term ( 12 months ) ( all P < 0.05 ) . Instead CPET indices and NYHA class improved after 12 months associated with restoration of HRV and BRS ( all P < 0.05 ) . We identified 26 responders to CRT according to changes in LVEF and diameters . Responders presented less depressed hemodynamic ( LVEF 25 + /- 1.0 vs 22 + /- 0.1 % ) , functional ( peak VO(2 ) 10.2 + /- 0.2 vs 6.9 + /- 0.3 ml/kg/min ) , and neurohormonal indices ( HRV 203.6 + /- 15.7 vs 147.6 + /- 10.ms , BRS 4.9 + /- 0.2 vs 3.6 + /- 0.3 ms/mmHg ) ( all P < 0.05 ) . In the multivariate analysis , peak VO(2 ) was the strongest predictor of responders . CONCLUSIONS Improvement in functional status is associated with restoration of neurohormonal reflex control at medium term . Less depressed functional status ( peak VO(2 ) ) was the strongest predictor of responders to CRT BACKGROUND Renal dysfunction is an important independent prognostic factor in heart failure ( HF ) .  Cardiac resynchronization therapy ( CRT ) improves functional status and left ventricular ( LV ) function in HF patients with ventricular dyssynchrony , but the impact of CRT on renal function is less defined . We hypothesized that CRT would improve glomerular filtration rate as estimated by the abbreviated Modification of Diet in Renal Disease equation ( eGFR ) . METHODS AND RESULTS The Multicenter InSync R and omized Clinical Evaluation ( MIRACLE ) study evaluated CRT in HF patients with NYHA Class III-IV , ejection fraction < or=35 % , and QRS > or=130 ms . Patients were evaluated before and 6 months after r and omization to control ( n = 225 ) or CRT ( n = 228 ) . Patients were categorized according to their baseline eGFR : > or=90 ( category A ) , 60 < or = eGFR < 90 ( category B ) , and 30 < or = eGFR < 60 ( category C ) mL/min per 1.73 m(2 ) . CRT improved LV function in all categories . Compared with control , CRT increased eGFR ( -2.4 + /- 1.2 vs. + 2.7 + /- 1.2 mL/min per 1.73 m(2 ) ; P = .003 ) and reduced blood urea nitrogen ( + 6.4 + /- 2.4 vs. -1.1 + /- 1.5 mg/mL ; P = .008 ) in category C , whereas no differences were observed in categories A and B. CONCLUSIONS CRT increased eGFR and reduced blood urea nitrogen  in HF patients with moderately reduced baseline eGFR . By improving cardiac function , CRT can indirectly improve renal function , underscoring the importance of cardiorenal interaction and providing another mechanism for the beneficial effects of CRT Cardiac resynchronization therapy ( CRT ) devices not only deliver effective treatment but may also serve as valuable diagnostic tools in heart failure management . In the present study , the minutes of daily physical activity and heart rate variability , measured by sensors incorporated into such a device , reflected the effects of CRT and were related to New York Heart Association functional class The prevalence of atrial fibrillation ( AF ) in patients with heart failure is high , but data about the effects of cardiac resynchronization therapy ( CRT ) in patients with chronic AF are scarce . In this prospect i ve observational study of 263 consecutive patients , CRT was performed in 96 patients ( 37 % ) with chronic AF and 167 patients ( 63 % ) with sinus rhythm ( SR ) .  Echocardiographic and clinical parameters were evaluated at baseline and 3 and 12 months . Reverse left ventricular ( LV ) remodeling is defined as LV end-systolic volume decrease > or = 10 % . Hospitalization rates for heart failure in the year before and after implantation were compared . Baseline characteristics between patients with and without AF were similar , but the AF group had smaller LV end-systolic and end-diastolic volumes and larger left atrial dimensions . New York Heart Association class , 6-minute walking distance , quality -of-life score , LV ejection fraction , and mitral regurgitation improved significantly at 3 and 12 months in both groups , and the changes were similar . Reverse LV remodeling after 3 and 12 months was 74 % and 82 % ( AF group ) versus 77 % and 83 % , respectively ( SR group , p = 0.79 ) . After 1 year , cardioversion had occurred in 25 % of patients with AF . In the year after implantation , significant decreases in hospitalizations for heart failure in both groups ( 84 % and 90 % ) were documented . Long-term mortality was almost equal in both groups . In conclusion , this large-scale study shows that the benefit of CRT in patients with chronic AF and heart failure is similar to that in patients with SR . Patients with chronic AF and heart failure should be considered c and i date s for CRT AIMS To compare the clinical response of patients with right ventricular apical pacing ( RVAP ) up grade d to  cardiac resynchronization therapy ( CRT ) to that of previously nonpaced heart failure ( HF ) patients who had de novo CRT implantation . BACKGROUND The role of CRT in patients with wide QRS and HF due to RVAP is less well established than in other CRT c and i date s. METHODS Ninety-eight consecutive patients with CRT were studied ( mean age 70 , mean ejection fraction 0.23 ) . Group A : patients having RVAP prior to CRT implantation ( n = 25 ) , group B : patients without prior RVAP ( n = 73 ) .  Clinical and echocardiographic parameters were recorded prior to , and 3 months after , CRT implantation . RESULTS Group A patients had a wider QRS at baseline compared to group B ( 203 + /- 32 ms vs 163 + /- 30 ms respectively , P < 0.001 ) , and a shorter 6-minute walking distance ( 222 + /- 118 m vs 362 + /- 119 m , respectively , P < 0.005 ) . Otherwise , clinical and echocardiographic parameters were not different . At follow up , group A patients had an average 0.7 + /- 0.5 decrease in their NYHA functional class , compared to 0.3 + /- 0.7 in group B patients ( P < 0.05 ) . Six-minute walking distance increased by 93 + /- 113 m in group A , versus 36 + /- 120 m in group B ( P = 0.22 ) . There was no difference in echocardiographic response to CRT between the groups . CONCLUSIONS HF patients with prior RVAP demonstrate clinical improvement after upgrading to CRT that is comparable , and in some aspects , even better than that observed in HF patients with native conduction delay who undergo de novo CRT implantation
Conclusion The results of our meta- analysis suggest that AF was associated with decreased CRT benefits in patients with HF .
CRT , however , benefits patients with AF with AVJ ablation
Background Cardiac resynchronisation therapy ( CRT ) is beneficial in selected patients with heart failure ( HF ) in normal sinus rhythm ( NSR ) .