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The new england journal of medicine on Morbidity and Mortality in Heart Failure John G.F. Cleland, M.D., Jean-Claude Daubert, M.D., Erland Erdmann, M.D., Nick Freemantle, Ph.D., Daniel Gras, M.D., Lukas Kappenberger, M.D., and Luigi Tavazzi, M.D., for the Cardiac Resynchronization — Heart Failure (CARE-HF) Study Investigators* b a c k g r o u n d
Cardiac resynchronization reduces symptoms and improves left ventricular function in From the Department of Cardiology, Castle Hill Hospital, Kingston-upon-Hull, United many patients with heart failure due to left ventricular systolic dysfunction and cardiac Kingdom (J.G.F.C.); the Department of dyssynchrony. We evaluated its effects on morbidity and mortality.
Cardiology, Hôpital Pontchaillou, Rennes,France (J.-C.D.); Klinik III für Innere Medi-zin der Universität zu Köln, Cologne, Ger- many (E.E.); the University of Birmingham, Patients with New York Heart Association class III or IV heart failure due to left ventricu- Edgbaston, United Kingdom (N.F.); Nou-lar systolic dysfunction and cardiac dyssynchrony who were receiving standard pharma- velles Cliniques Nantaises, Nantes, France (D.G.); the Division of Cardiology, Centre cologic therapy were randomly assigned to receive medical therapy alone or with cardiac Hospitalier Universitaire Vaudois, Lau- resynchronization. The primary end point was the time to death from any cause or an sanne, Switzerland (L.K.); and Istituto diunplanned hospitalization for a major cardiovascular event. The principal secondary end Ricovero e Cura a Carattere Scientifico, Policlinico San Matteo, Pavia, Italy (L.T.).
Address reprint requests to Dr. Cleland atthe Department of Cardiology, Castle Hill Hospital, University of Hull, Kingston-upon-Hull, United Kingdom, or at j.g.cleland@ A total of 813 patients were enrolled and followed for a mean of 29.4 months. The pri- hull.ac.uk.
mary end point was reached by 159 patients in the cardiac-resynchronization group, ascompared with 224 patients in the medical-therapy group (39 percent vs. 55 percent; *The CARE-HF Study investigators are hazard ratio, 0.63; 95 percent confidence interval, 0.51 to 0.77; P<0.001). There were82 deaths in the cardiac-resynchronization group, as compared with 120 in the medi- This article was published at www.nejm.
cal-therapy group (20 percent vs. 30 percent; hazard ratio 0.64; 95 percent confidence org on March 7, 2004.
interval, 0.48 to 0.85; P<0.002). As compared with medical therapy, cardiac resynchro- N Engl J Med 2005;352:1539-49.
nization reduced the interventricular mechanical delay, the end-systolic volume index, Copyright 2005 Massachusetts Medical Society.
and the area of the mitral regurgitant jet; increased the left ventricular ejection fraction;and improved symptoms and the quality of life (P<0.01 for all comparisons).
c o n c l u s i o n s
In patients with heart failure and cardiac dyssynchrony, cardiac resynchronization im-proves symptoms and the quality of life and reduces complications and the risk of death.
These benefits are in addition to those afforded by standard pharmacologic therapy.
The implantation of a cardiac-resynchronization device should routinely be consideredin such patients.
Downloaded from www.nejm.org by DR STEPHEN PETTIT on February 4, 2006 . Copyright 2005 Massachusetts Medical Society. All rights reserved. The new england journal of medicine organization (Quintiles, Dublin) that maintained cologic treatment, many patients with the database, issued data-clarification forms, and dheart failure have severe and persistent assisted by Medtronic employees, verified source symptoms, and their prognosis remains poor.1,2 documents. The sponsor had no access to the data-
Such patients commonly have regions of delayed base and did not participate in the analysis of the re-
myocardial activation and contraction, leading to sults or the writing of the article. All analyses were
cardiac dyssynchrony. In a series of trials lasting up performed by one of the authors with the assistance
to six months, cardiac resynchronization decreased of an independent statistician. Three Medtronic rep-
symptoms and improved exercise capacity, the qual- resentatives commented on the manuscript before
ity of life, and ventricular function.3-7 The Compar- its submission. The study was approved by the local
ison of Medical Therapy, Pacing, and Defibrillation ethics committee of each participating institution
in Heart Failure (COMPANION) trial showed that and by appropriate national ethics committees. All
cardiac-resynchronization therapy alone or com- patients provided written informed consent.
bined with an implantable defibrillator reduced the
composite end point of death from any cause or hos- patients
pitalization during a mean follow-up of 16 months8; Eligible patients were at least 18 years of age, had
however, the decrease in the risk of death was not had heart failure for at least six weeks, and were in
significant with cardiac resynchronization therapy New York Heart Association (NYHA) class III or IV
alone (P=0.06). Meta-analyses have left lingering despite receipt of standard pharmacologic therapy,
uncertainty about the effects of cardiac resynchro- with a left ventricular ejection fraction of no more
nization on the risk of complications and death.9,10 than 35 percent, a left ventricular end-diastolic di-
We analyzed the effects of cardiac resynchroniza- mension of at least 30 mm (indexed to height), and
tion on the risk of complications and death among a QRS interval of at least 120 msec on the electro-
patients who were receiving standard medical ther- cardiogram. Patients with a QRS interval of 120 to
apy for moderate or severe heart failure and cardiac 149 msec were required to meet two of three addi-
dyssynchrony.
tional criteria for dyssynchrony: an aortic preejec-tion delay of more than 140 msec, an interventric-ular mechanical delay of more than 40 msec, or delayed activation of the posterolateral left ventric- The Cardiac Resynchronization — Heart Failure ular wall.11-13(CARE-HF) trial was a multicenter, international, Patients who had had a major cardiovascular randomized trial comparing the effect on the risk event in the previous six weeks, those who had con-
of complications and death of standard pharmaco- ventional indications for a pacemaker or an im-
logic therapy alone with that of the combination of plantable defibrillator, and those with heart fail-
standard therapy and cardiac resynchronization ure requiring continuous intravenous therapy were
(without a defibrillator) in patients with left ventric- excluded. Also excluded were patients with atrial ar-
ular systolic dysfunction, cardiac dyssynchrony, and rhythmias, since such patients cannot benefit from
symptomatic heart failure.11-13 Patients were en- the atrial component of resynchronization.11-13
rolled at 82 European centers; enrollment began in
January 2001 and ended in March 2003. The study study procedures
was not blinded. The members of the end-points Randomization was stratified according to the
committee (see the Appendix), however, were not NYHA class and was carried out by Quintiles with
aware of patients’ treatment assignments. Patients the use of a minimization procedure. Patients who
in the control group were not scheduled to receive a were randomly assigned to undergo cardiac resyn-
device, both for ethical reasons and so that the trial chronization received a Medtronic InSync or InSync
could assess the entire effect of cardiac resynchro- III device, which provided atrial-based, biventricular
nization, including complications associated with stimulation with the use of standard right ventricu-
implantation of the device.11-13
lar and Attain (Medtronic) left ventricular leads. In- The steering committee (see the Appendix) de- vestigators were asked to position the left ventricular signed the trial. The Medtronic Corporation funded lead to pace the lateral or posterolateral left ventric-the trial and provided a study manager to supervise ular wall transvenously and provide radiographicits conduct. Data were sent by investigators to core documentation. Backup atrial pacing was set at 60laboratories or to an independent clinical-research beats per minute. The interventricular delay was set Downloaded from www.nejm.org by DR STEPHEN PETTIT on February 4, 2006 . Copyright 2005 Massachusetts Medical Society. All rights reserved. e f f e c t o f c a r d i a c r e s y n c h r o n i z a t i o n o n h e a r t f a i l u r e to zero, and the atrioventricular delay was echocar- All hospitalizations were adjudicated in a blind- diographically optimized.11 Patients were moni- ed fashion by the end-points committee. The firsttored overnight after receiving the device. If the hospitalization with documented worsening heartinitial procedure failed, repeated attempts at im- failure, myocardial infarction, unstable angina, ar-plantation were encouraged, and expert assistance rhythmia, stroke, or other major cardiovascularwas provided.
event (e.g., pulmonary embolism or ruptured aorticaneurysm) or hospitalization owing to or prolonged f o l l o w - u p
by a serious procedure-related event (e.g., infection, Patients were evaluated at 1, 3, 6, 9, 12, and 18 pericardial hemorrhage, or tension pneumothorax)months and every six months thereafter, and stan- was counted in the primary end point. Hospitaliza-dard medications were adjusted as appropriate at tion with worsening heart failure was defined by thethese visits. Investigators were asked to report all occurrence of increasing symptoms and the needadverse events, which were classified in a blinded for treatment with intravenous diuretics or a sub-fashion by an end-points committee or, if they were stantial increase in oral diuretics (an increase of atprocedure-related or device-related, by an indepen- least 40 mg of furosemide per day, 1 mg of bumet-dent expert who was not blinded to the study-group anide per day, or 10 mg of torsemide per day) or theassignments (see the Appendix).
initiation of a combination of a thiazide and a loop The protocol required follow-up to continue for diuretic.
18 months after the last patient had been enrolled, Admissions for symptoms without a document- unless the data and safety monitoring board stopped ed major cardiac event were not included in thethe study earlier or fewer than 300 patients had primary end point, nor were readmissions for leadreached a primary end point at that time, in which displacement, unless it precipitated a cardiac emer-case the trial could be extended. On March 6, 2004, gency, or admissions for initial implantation of thethe board recommended extending the study until device, since this was part of the protocol. To pre-May 2005 without disclosing the reasons. However, vent bias in favor of cardiac resynchronization, hos-since the prespecified criteria had been met, the pitalizations within 10 days after randomization insteering committee decided to conclude the study either group did not count toward the primary endas planned on September 30, 2004,11 and imple- point.
mented, without knowledge of the results, an exten- The principal secondary outcome was death sion phase with death from any cause as the (nom- from any cause, which was classified according toinal) primary outcome. On February 24, 2005, after mode and cause.11 Other secondary end points in-this article had been submitted for publication, the cluded a composite of death from any cause and un-data and safety monitoring board indicated that the planned hospitalization with heart failure and, atmain reasons for its recommendation were interim 90 days, the NYHA class and the quality of life as as-analyses showing a trend toward more cardiovas- sessed by the patient with the use of the Minnesotacular events in the first 10 days after randomization Living with Heart Failure questionnaire (scores canamong patients assigned to cardiac resynchroniza- range from 0 to 105, with higher scores reflecting ation than among those assigned to medical therapy poorer quality of life)14,15 and the European Qualityalone and a trend toward a favorable effect of re- of Life–5 Dimensions (EuroQoL EQ-5D) instrumentsynchronization on long-term mortality that they (scores can range from –0.594 to 1.000, with lowerthought might fail to reach significance by the time numerical values indicating a poorer quality of life;of the planned closure date.
negative scores are associated with a quality of lifethat is considered worse than death).16 Death was e n d p o i n t s
given a notional NYHA class of V for the analysis of The primary end point was a composite of death changes in functional class. Several echocardio-from any cause or an unplanned hospitalization for graphic and biochemical variables were assessed ina major cardiovascular event; only the first event in core laboratories, including the severity of cardiaceach patient was included in this analysis. Data on dyssynchrony, ventricular function, mitral regurgi-patients who underwent elective heart transplanta- tation, and N-terminal pro–brain natriuretic peptidetion were censored seven days after the procedure. (Elecsys, Roche Diagnostics), at baseline and at theEmergency heart transplantation was counted as a 3-month and 18-month follow-up visits. Differenc-death.
es from baseline in heart rate and blood pressure Downloaded from www.nejm.org by DR STEPHEN PETTIT on February 4, 2006 . Copyright 2005 Massachusetts Medical Society. All rights reserved. The new england journal of medicine were also compared in the two groups at follow- Implantation of a device was attempted in 404 up.11 No data other than NYHA class were imputed of the 409 patients assigned to undergo cardiac re-for patients who died.
synchronization. One patient died before undergo-ing the procedure, and in four instances, the patient s t a t i s t i c a l a n a l y s i s
or investigator decided not to proceed. A cardiac- All prespecified analyses were conducted according resynchronization device was implanted and activat-to the intention-to-treat principle. P values other ed in 390 patients (95 percent), in 349 on the firstthan for the primary end point are nominal. The attempt; the device was implanted a median of fourstudy had a statistical power17 of 80 percent to iden- days (interquartile range, two to seven) after ran-tify a 14 percent relative reduction or a 5.7 percent- domization. The median duration of hospitalizationage point reduction in the rate of events, given a con- for implantation was five days (interquartile range,ventional one-sided a value of 0.025 and a predicted two to eight). Before the device could be activated,number of 300 events.11 The time to an event was six patients had an unplanned hospitalization forcalculated according to the Kaplan–Meier method cardiovascular reasons that qualified as a primaryand analyzed with the use of Cox proportional-haz- end point. Eight patients assigned to undergo car-ards models, which included baseline NYHA class diac resynchronization had a device with an addi-as a covariate.18 Continuous data were analyzed tional defibrillator function implanted during thewith the use of mixed models, which included base- study.
line variables as patient-level covariates and study In the medical-therapy group, implantation of centers as random effects.19 Dichotomous out- a cardiac-resynchronization device alone was at-comes were analyzed with the use of nonlinear tempted in 43 patients and implantation of a resyn-mixed models, which included the NYHA class as a chronization device with a defibrillator was attempt-patient-level covariate and study centers as random ed in 23 patients (both approaches were attemptedeffects. The rates of adverse events were compared in 1 patient). The device was activated in 50 patients.
between groups by means of Fisher’s exact test. In 10 instances, a device was successfully implantedAnalyses were conducted with the use of SAS soft- but programmed to provide only standard pacemak-ware (version 9.12, SAS Institute). The data and er or defibrillator functions to avoid crossover. Insafety monitoring board conducted two planned in- five patients, the attempt at implantation was un-terim analyses with the use of nonsymmetric stop- successful. The device was activated in 19 patientsping rules.20 (5 percent) before they reached the primary endpoint. Eight of these patients subsequently reacheda primary end point, six of whom died. Of 31 pa- tients in whom the device was activated after they A total of 404 patients were assigned to receive med- had reached the primary end point, 7 subsequent-
ical therapy alone and 409 to receive medical therapy ly died.
plus cardiac resynchronization. The mean duration
of follow-up was 29.4 months (range, 18.0 to 44.7). primary end point
By the end of the study, the survival status of all pa- By the end of the study, the primary end point had
tients was known, 383 patients had reached the pri- been reached in 159 patients in the cardiac-resyn-
mary end point, and 202 patients had died.
chronization group, as compared with 224 patientswho received medical therapy alone (39 percent vs.
s t u d y p o p u l a t i o n
55 percent; hazard ratio, 0.63; 95 percent confi- Baseline characteristics were similar in the two dence interval, 0.51 to 0.77; P<0.001) (Fig. 1A andgroups (Table 1). Patients had well-treated moder- Table 2). There were 384 unplanned hospitaliza-ate or severe heart failure and major left ventricular tions for a major cardiovascular event in the controlsystolic dysfunction. Only 43 percent were taking group and 222 in the cardiac-resynchronizationhigh doses of diuretics (defined as at least 80 mg of group. Death was the primary event in 74 patients,furosemide, at least 2 mg of bumetanide, or at least and hospitalization in 309. Prespecified subgroup20 mg of torsemide). Beta-blockers were taken at analyses for the primary end point revealed no het-some time during the study by 85 percent of the pa- erogeneity in the effect of cardiac resynchronizationtients in the medical-therapy group and 84 percent (Fig. 2). Twelve patients in the cardiac-resynchro-of those in the cardiac-resynchronization group.
nization group and 10 in the medical-therapy group Downloaded from www.nejm.org by DR STEPHEN PETTIT on February 4, 2006 . Copyright 2005 Massachusetts Medical Society. All rights reserved. e f f e c t o f c a r d i a c r e s y n c h r o n i z a t i o n o n h e a r t f a i l u r e Table 1. Baseline Characteristics of the Patients.*
Medical Therapy Alone
Medical Therapy plus Cardiac
Characteristic
Resynchronization (N=409)
N-terminal pro–brain natriuretic peptide (pg/ml)† Left ventricular end-systolic volume index (ml/m2) Glomerular filtration rate (ml/min/1.73 m2) Use of an ACE inhibitor or angiotensin-receptor blocker (%) * NYHA denotes New York Heart Association, and ACE angiotensin converting enzyme.
† To convert values for N-terminal pro–brain natriuretic peptide to picomoles per liter, divide by 8.457.
‡ The area was calculated as the area of the color-flow Doppler regurgitant jet divided by the area of the left atrium in sys- § A high-dose loop diuretic consisted of furosemide at a dose of 80 mg or more, bumetanide at a dose of 2 mg or more, or torsemide at a dose of 20 mg or more.
Downloaded from www.nejm.org by DR STEPHEN PETTIT on February 4, 2006 . Copyright 2005 Massachusetts Medical Society. All rights reserved. The new england journal of medicine 30 percent; hazard ratio, 0.64; 95 percent confi- dence interval, 0.48 to 0.85; P<0.002) (Fig. 1B and Table 2). The principal cause of death was cardio-vascular in 167 patients (83 percent), noncardiovas- cular in 34 patients (17 percent), and not classifi-able in 1 patient (0.5 percent). The cause of death was attributed to worsening heart failure in 56 of the 120 patients who died in the medical-therapygroup (47 percent) and in 33 of the 82 patients whodied in the cardiac-resynchronization group (40 per- Cardiovascular Event
Hospitalization for a Major
cent). The mode of death was classified as sudden from Any Cause or Unplanned
in 38 of the 120 patients who died in the medical- Percentage of Patients Free of Death
therapy group (32 percent) and in 29 of the 82 pa- tients who died in the cardiac-resynchronization group (35 percent). The mortality rate in the med- No. at Risk
ical-therapy group was 12.6 percent at one year and 25.1 percent at two years, as compared with 9.7 per- cent and 18.0 percent, respectively, in the cardiac-resynchronization group. There were three emergency and six elective heart transplantations in the medical-therapy group and one emergency and nine elective heart trans- plantations in the cardiac-resynchronization group.
All the patients who underwent emergency hearttransplantation died. None of the patients who un- derwent elective transplantation had died withinseven days after transplantation, at which point their follow-up data were censored from the analysis. Percentage of Patients Free
of Death from Any Cause
o t h e r s e c o n d a r y e n d p o i n t s
As compared with medical therapy alone, cardiac resynchronization reduced the risk of the composite end point of death from any cause or hospitalization No. at Risk
Cardiac resyn-
for worsening heart failure (hazard ratio, 0.54; 95 percent confidence interval, 0.43 to 0.68; P<0.001) (Table 2). There were 252 hospitalizations for wors- Figure 1. Kaplan–Meier Estimates of the Time to the Primary End Point
ening heart failure among 133 patients in the (Panel A) and the Principal Secondary Outcome (Panel B).
medical-therapy group (33 percent) and 122 such The primary outcome was death from any cause or an unplanned hospitaliza- hospitalizations among 72 patients in the cardiac- tion for a major cardiovascular event. The principal secondary outcome was resynchronization group (18 percent).
As compared with patients in the medical-ther- apy group, patients in the cardiac-resynchronizationgroup had less severe symptoms (P<0.001) and a had unplanned hospitalizations for a major cardio- better quality of life (P<0.001) at 90 days (Table 2).
vascular event that occurred within 10 days after At 90 days, 15 patients had died in the medical-ther-randomization and were therefore not counted as apy group and 12 patients had died in the cardiac-primary end points.
resynchronization group. At 18 months, 105 of thepatients in the cardiac-resynchronization group were in NYHA class I, 150 were in NYHA class II, In the cardiac-resynchronization group, 82 patients and 80 were in NYHA class III or IV; the respectivedied, as compared with 120 patients who had been values in the medical-therapy group were 39, 112,assigned to medical therapy alone (20 percent vs. and 152.
Downloaded from www.nejm.org by DR STEPHEN PETTIT on February 4, 2006 . Copyright 2005 Massachusetts Medical Society. All rights reserved. e f f e c t o f c a r d i a c r e s y n c h r o n i z a t i o n o n h e a r t f a i l u r e Table 2. Study Outcomes in Analyses Stratified According to NYHA Class.*
Medical Therapy
Medical Therapy plus
Cardiac Resynchronization
Hazard Ratio
Primary outcome
Secondary outcome
planned hospitalization with worsening heart failure Medical Therapy
Medical Therapy plus
Cardiac Resynchronization Difference in Means
(95% CI)‡
Continuous outcome
* Plus–minus values are means ±SD. The analysis was adjusted according to study center. NYHA denotes New York Heart Association, and CI confidence interval.
† These events contributed to the primary or secondary outcome.
‡ The difference shown is for the cardiac-resynchronization group as compared with the medical-therapy group. § Scores on the Minnesota Living with Heart Failure questionnaire range from 0 to 105, with higher scores reflecting a ¶ Scores on the European Quality of Life–5 Dimensions (EuroQoL EQ-5D) instrument range from –0.594 to 1.000, with 1.000 indicating fully healthy and 0 dead.
e c h o c a r d i o g r a p h i c , b i o c h e m i c a l ,
s e r i o u s a d v e r s e e v e n t s
a n d h e m o d y n a m i c a s s e s s m e n t s
There was one device-related death in each group: At both 3 months and 18 months, the left ventricular one patient in the cardiac-resynchronization groupejection fraction was significantly greater, the left died of heart failure aggravated by lead displace-ventricular end-systolic volume index was signifi- ment, and one patient in the medical-therapy groupcantly lower, the area of mitral regurgitation was died of septicemia after receiving a device. Thesignificantly smaller, and the interventricular me- most common adverse device- or procedure-relatedchanical delay was significantly shorter in the car- events in the cardiac-resynchronization group werediac-resynchronization group than in the medical- lead displacement (24 patients), coronary-sinus dis-therapy group (Table 3). By 18 months, plasma section (10 patients), pocket erosion (8 patients),levels of N-terminal pro–brain natriuretic peptide pneumothorax (6 patients), and device-related in-were lower among patients in the cardiac-resyn- fection (3 patients). Worsening heart failure waschronization group (Table 3). Systolic blood pres- more common in the medical-therapy group (affect-sure was higher at both 3 months and 18 months ing 263 patients, as compared with 191 patientsamong patients in the cardiac-resynchronization in the cardiac-resynchronization group; P<0.001),group.
whereas atrial arrhythmias or ectopy was more com- Downloaded from www.nejm.org by DR STEPHEN PETTIT on February 4, 2006 . Copyright 2005 Massachusetts Medical Society. All rights reserved. The new england journal of medicine mon in the cardiac-resynchronization group (af-fecting 64 patients in that group, as compared with Figure 2 (facing page). Effect of Cardiac Resynchroniza-
tion on the Primary End Point in Predefined Subgroups.
41 in the medical-therapy group; P=0.02). The fre- Hazard ratios and 95 percent confidence intervals (CIs) quencies of respiratory tract infections, hypoten- are shown. The subgroups of age, systolic blood pres- sion, falls or syncope, acute coronary syndromes, sure, mitral-regurgitation area (as defined in Table 1), renal dysfunction, ventricular arrhythmias or ecto- interventricular mechanical delay, ejection fraction, end- py, and neurologic events were similar in the two systolic volume index, and glomerular filtration rate are divided according to the median value in the study popu-lation. All analyses were stratified according to the NYHA class, except the subgroup analysis of NYHA class. To convert values for N-terminal probrain natriuretic pep-tide (NT-BNP) to picomoles per liter, divide by 8.457. For We found that cardiac resynchronization substan- some data (QRS width, for instance), many patients had tially reduced the risk of complications and death results at the median value, and this led to some inequal-ity in the sizes of the subgroups. Because of missing among patients with moderate or severe heart fail- baseline data, not all subgroup numbers total 813. ure owing to left ventricular systolic dysfunction andcardiac dyssynchrony. The benefits were similaramong patients with ischemic heart disease and pa-tients without ischemic heart disease and were in The extent to which risk can be modified may beaddition to those afforded by pharmacologic thera- greater among patients with less severe disease.
py. The data are consistent with a resynchronization- Cardiac resynchronization may be beneficial in pa-induced reduction in cardiac dyssynchrony, leading tients with cardiac dyssynchrony even if their symp-to a sustained increase in left ventricular perfor- toms are not severe, although we excluded patientsmance and a diminution of mitral regurgitation and, judged by the investigator to be in NYHA class I or II.
in turn, a rise in perfusion pressure, a fall in cardiac The hazard ratio for death among patients with a filling pressure, and favorable left ventricular re- cardiac-resynchronization device, as compared withmodeling. These changes in function translate into those receiving medical therapy alone (0.64; 95 per-improvements in well-being and decreases in symp- cent confidence interval, 0.48 to 0.85; P<0.002),toms, complications, and the risk of death.
was similar to that among patients who received The favorable effects of cardiac resynchroniza- both a resynchronization device and a defibrillator, tion on symptoms, the quality of life, ventricular as compared with medical therapy alone, in thefunction, and blood pressure in our trial are similar COMPANION trial (0.64; 95 percent confidence in-to those reported in previous trials.4-8 However, we terval, 0.48 to 0.86; P=0.003).8 The COMPANIONalso found that cardiac resynchronization signifi- trial was not designed to investigate differences be-cantly reduced the risk of death. Calculations based tween the use of a cardiac-resynchronization deviceon hazard ratios suggest that, for every nine devic- alone and the combination of a resynchronizationes implanted, one death and three hospitalizations device and an implantable defibrillator, but much offor major cardiovascular events are prevented. This the effect of the latter approach could be explainedeffect is in addition to the benefits of pharmacolog- by the cardiac-resynchronization component. In ouric therapy and is similar to the reduction in the risk study, the cardiac-resynchronization group had aof death associated with beta-blocker therapy as decreased incidence of sudden death and a de-compared with placebo in a similar population.21 creased incidence of death from worsening heart The benefit of cardiac resynchronization therapy failure, both of which may reflect an improvement in our study was due, at least in part, to the adher- in cardiac function. A defibrillator might furtherence of patients and investigators to the protocol reduce the risk of sudden death.25,26 Twenty-nineand to the increasing effect of cardiac resynchroni- patients (7 percent) in the cardiac-resynchroniza-zation over a long follow-up period, but it was not tion group died suddenly. due to the recruitment of patients at higher risk for Retarding the progression of cardiac dysfunction events than those in other studies. Indeed, the mor- to prevent malignant arrhythmias may be a bettertality rate was lower than that in many other studies, strategy than treating malignant arrhythmias oncepossibly reflecting the high standard of care, the they occur, because defibrillation is stressful to thepresence of less severe heart failure, or both.22-24 patient and associated with an adverse prognosis, Downloaded from www.nejm.org by DR STEPHEN PETTIT on February 4, 2006 . Copyright 2005 Massachusetts Medical Society. All rights reserved. e f f e c t o f c a r d i a c r e s y n c h r o n i z a t i o n o n h e a r t f a i l u r e Patients with Event/Total No. of Patients
Hazard Ratio (95% CI)
Resynchronization Better
Medical Therapy Better
Downloaded from www.nejm.org by DR STEPHEN PETTIT on February 4, 2006 . Copyright 2005 Massachusetts Medical Society. All rights reserved. The new england journal of medicine Table 3. Hemodynamic, Echocardiographic, and Biochemical Assessments.*
Difference in Means
Difference in Means
Variable
at 3 Mo (95% CI)
at 18 Mo (95% CI)
N-terminal pro–brain natriuretic peptide * Differences were not adjusted for the higher mortality rate in the medical-therapy group. A plus sign indicates a greater value, and a minus sign a smaller value, in the cardiac-resynchronization group than in the medical-therapy group. CI de-notes confidence interval.
† The area was calculated as the area of the color-flow Doppler regurgitant jet divided by the area of the left atrium in sys- ‡ To convert the values for N-terminal pro–brain natriuretic peptide to picomoles per liter, divide by 8.457.
owing either to the cause of the arrhythmia or to Hull and East Yorkshire Cardiac Trust, Medtronic, Vasomedical, andthe effects of the shock.27 Assuming that the com- Abbott. Dr. Daubert reports having served as a consultant for and having received speakers’ honoraria from Medtronic and St. Jude bination of a cardiac-resynchronization device and Medical. Dr. Erdmann reports having served as a consultant for anda defibrillator could prevent two thirds of sudden having received speakers’ honoraria from Takeda, Merck (Darm-deaths, a future study would require 1300 patients stadt), Medtronic, and Guidant. Dr. Freemantle reports having served as a consultant for Medtronic and Pfizer and having received per group and a follow-up period similar to ours to speakers’ honoraria from Medtronic and grant support fromhave a statistical power of 90 percent to detect an ab- Medtronic, Aventis, Amgen (United Kingdom), and the Britishsolute reduction in the risk of death from any cause Heart Foundation. Dr. Gras reports having served as a consultant for and having received speakers’ honoraria from Medtronic and of 5 percent with the use of combination therapy, Guidant. Dr. Kappenberger reports having served as a consultantas compared with the use of cardiac resynchroniza- for Medtronic, having received speakers’ honoraria from Medtron-tion alone.
ic, Biotronik, and Guidant, and having received grant support fromMedtronic and the Swiss National Foundation for Scientific Re- In summary, we found that cardiac resynchroni- search, Commission for Technology and Innovation/Kommission zation is an effective therapy for patients with left für Technologie und Innovation, and the Swiss Heart Foundation.
ventricular systolic dysfunction and cardiac dyssyn- Dr. Tavazzi reports having served as a consultant for Medtronic, Me- narini, Servier, and Pfizer and having received speakers’ honoraria chrony who have moderate or severe heart failure from Medtronic, Novartis, and Takeda.
and who are in sinus rhythm.
This article is dedicated to the memory of Werner Klein, profes- Supported by a grant from Medtronic.
sor of cardiology at the University Hospital of Graz (Austria), a Dr. Cleland reports having served as a consultant for Medtronic, member of the steering committee who died in 2004. He contribut- Amgen, Menarini, and Pfizer and having received speakers’ hono- ed substantially to the design and conduct of the study but did not raria from Medtronic, Takeda, AstraZeneca, and Pfizer and grant live to see it completed. His wise counsel is greatly missed by his col- support from the Medical Research Council (United Kingdom), a p p e n d i x
The following persons participated in the CARE-HF Study: Steering Committee — J.G.F. Cleland (chair), J.-C. Daubert, E. Erdmann, D.
Gras, L. Kappenberger, W. Klein, L. Tavazzi; Data and Safety Monitoring Board — P.A. Poole-Wilson, L. Rydén (chair), H. Wedel, H.J.J.
Wellens; End-Points Committee — B. Uretsky, K. Thygesen; Independent Device-Related Adverse-Event Assessor — D. Böcker; Study
Management — M.M.H. Marijianowski; Statistical Analysis — N. Freemantle, M.J. Calvert; Pharmacologic Vigilance and Data Manage-
ment — Quintiles; Investigators — Austria: G. Christ, F. Fruhwald, R. Hofmann, A. Krypta, F. Leisch, R. Pacher, F. Rauscha; Belgium: R. Tav-
ernier; Denmark: P.E. Bloch Thomsen, S. Boesgaard, H. Eiskjær, G.T. Esperen, J. Haarbo, A. Hagemann, E. Korup, M. Møller, P. Mortensen,
P. Søgaard, T. Vesterlund; Finland: H. Huikuri, K.I. Niemelä, L. Toivonen; France: F. Bauer, A. Cohen-Solal, C. Crocq, P. Djiane, J.L. Dubois-
Rande, P. de Groote, Y. Juilliere, G. Kirkorian, M. Komajda, T. Laperche, H. Le Marec, C. Leclercq, C. Tribouilloy; Germany: F. Er, E. Fleck,
U.C. Hoppe, F.X. Kleber, B. Maisch, J. Neuzner, C. Reithmann, T. Remp, C. Schmitt, C. Stahl, R.H. Strasser; Italy: M.C. Albanese, A. Bar-
toloni, M. Bocchiardo, A. Capucci, A. Carboni, A. Circo, M. Disertori, R. del Medico, T. Forzani, M. Frigerio, A. Gavazzi, M. Landolina, M.
Downloaded from www.nejm.org by DR STEPHEN PETTIT on February 4, 2006 . Copyright 2005 Massachusetts Medical Society. All rights reserved.
e f f e c t o f c a r d i a c r e s y n c h r o n i z a t i o n o n h e a r t f a i l u r e Lunati, S. Mangiameli, M. Piacenti, A. Pitì, P.A. Ravazzi, A. Raviele, M. Santini, A. Serio, G.P. Trevi, M. Volterrani, M. Zardini; the Netherlands:
F.A.L.E. Bracke, C.C. de Cock, A. Meijer, R. Tukkie; Spain: J. Casares Mediavilla, M. Concha, J.F. Delgado, A. González-García, R. Muñoz-
Aguilera, J. Martínez Ferrer, F. Ridocci; Sweden: B. Andren, J. Brandt, P. Blomström, M. Edner, K. Hellström, S. Jensen, B. Kristensson, F. Ma-
ru, S.J. Moller, F. Rönn, P. Smedgård, G. Wikström; Switzerland: J. Fuhrer, G. Girod; United Kingdom: G.H. Broomes, S. Chalil, H. Dargie, W.
Davies, A. Delaney, P. Elliott, G.K. Goode, G. Haywood, G.C. Kaye, A.S. Kurbaan, R. Lane, T. Levy, F. Leyva, H. Marshall, S. Muhyaldeen, N.
Nitikin, M.J.D. Roberts, J.D. Skehan, W.D. Toff, D.J. Wright; Core Echocardiography Laboratory (Pavia, Italy) — C. Bassi, S. Ghio, E. Ghiz-
zardi, G. Magrini, M. Pasotti, V. Pierota, E. Tellaroli, A. Serio, L. Scelsi; Core Neuroendocrine Laboratory (Graz, Austria) — A. Fahrleitner,
G. Leb, H. Wenisch; Therapy Delivery (Kingston-upon-Hull, United Kingdom) — A. Bennett, M. Cooklin, J. Ghosh, S. Hurren, G.C. Kaye,
N.K. Khan.
r e f e r e n c e s
10. Calvert M, Freemantle N, Cleland JG.
20. Lan KKG, DeMets DL. Discrete sequen-
JGF. Is the prognosis of heart failure im- Cardiac resynchronization therapy in heart tial boundaries for clinical trials. Biometrika proving? J Am Coll Cardiol 2000;36:2284-6.
failure. Ann Intern Med 2005;142:305-7.
11. Cleland JGF, Daubert JC, Erdmann E, et
21. CIBIS-II Investigators and Committee.
cumulative benefits of triple therapy to im- al. The CARE-HF study (Cardiac Resynchro- The Cardiac Insufficiency Bisoprolol Study prove outcomes in heart failure: too many nisation in Heart Failure study): rationale, II (CIBIS-II): a randomised trial. Lancet cooks will spoil the broth. J Am Coll Cardiol 22. Packer M, Coats AJS, Fowler MB, et al.
12. Calvert MJ, Freemantle N, Cleland JGF.
Effect of carvedilol on survival in severe associations. N Engl J Med 2004;350:2193-5.
chronic heart failure. N Engl J Med 2001; Cazeau S, Leclercq C, Lavergne T, et al.
health-related quality of life data acquired in Effects of multisite biventricular pacing in the baseline phase of the CARE-HF study.
23. The CONSENSUS Trial Study Group.
patients with heart failure and intraventricu- Effects of enalapril on mortality in severe 13. Cleland JGF, Daubert JC, Erdmann E, et
congestive heart failure: results of the Coop- al. Baseline characteristics of patients re- erative North Scandinavian Enalapril Surviv- Young JB, Abraham WT, Smith AL, et al.
cruited into the CARE-HF study. Eur J Heart implantable cardioversion defibrillation in 14. Rector TS, Tschumperlin LK, Kubo SH,
24. Pitt B, Zannad F, Remme WJ, et al. The
advanced chronic heart failure: the MIRACLE et al. Use of the Living With Heart Failure effect of spironolactone on morbidity and questionnaire to ascertain patients’ per- mortality in patients with severe heart fail- Abraham WT, Fisher WG, Smith AL, et al.
spectives on improvement in quality of life Cardiac resynchronization in chronic heart versus risk of drug-induced death. J Card 25. Bardy GH, Lee KL, Mark DB, et al.
failure. N Engl J Med 2002;346:1845-53.
Higgins SL, Hummel JD, Niazi IK, et al.
15. Rector TS, Kubo SH, Cohn JN. Validity
er–defibrillator for congestive heart failure.
Cardiac resynchronization therapy for the of the Minnesota Living with Heart Failure treatment of heart failure in patients with in- questionnaire as a measure of therapeutic 26. Cleland JGF, Ghosh J, Freemantle N, et
traventricular conduction delay and malig- response to enalapril or placebo. Am J Car- al. Clinical trials update and cumulative meta-analyses from the American College of 16. Brooks R. EuroQol: the current state of
Bristow MR, Saxon LA, Boehmer J, et al.
Cardiac-resynchronization therapy with or 17. Shih JH. Sample size calculation for
ids and cardiac resynchronisation therapy in without an implantable defibrillator in ad- complex clinical trials with survival end- heart failure. Eur J Heart Fail 2004;6:501-8.
vanced chronic heart failure. N Engl J Med points. Control Clin Trials 1995;16:395-407.
27. Moss AJ, Greenberg H, Case RB, et al.
18. Collett D. Modelling survival data in
Long-term clinical course of patients after medical research. London: Chapman & Hall, termination of ventricular tachyarrhythmia al. Systematic review: cardiac resynchroni- by an implanted defibrillator. Circulation zation in patients with symptomatic heart 19. McCulloch CE, Searle SR. Generalized,
failure. Ann Intern Med 2004;141:381-90.
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