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European Journal of Heart Failure 2000 2(4):399-406; doi:10.1016/S1388-9842(00)00113-6
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© 2000 European Society of Cardiology

Reduction of hospital days by biventricular pacing

Frieder Braunschweig, Cecilia Linde*, Fredrik Gadler and Lars Rydén

Department of Cardiology, Karolinska Hospital S-117 76 Stockholm, Sweden

* Corresponding author. Tel.: +46-8-517-76068; fax: 46-8-664-48-45. frbr{at}cardio.ks.se (C. Linde).


   Abstract
Top
 Abstract
1. Introduction
 2. Methods
 3. Results
 4. Discussion
 References
 
The health care costs for heart failure are substantial. Studies indicate that hospital treatment constitutes 65–75% of these. The aim of this study was to assess total and heart failure related hospital days as well as safety and efficacy of biventricular pacing in 16 patients with severe heart failure and delayed intraventricular conduction (QRS duration <150 ms). They were implanted with a biventricular pacemaker and followed by NYHA class, 6-min walk test and quality of life for a mean of 291±76 days. Total number of hospital days and the need for hospitalisations were monitored. Thirteen responders improved by at least one functional class. After 6 months of pacing the 6-min walk test improved from 375±83 m to 437±73 m (P<0.001) and Minnesota Living with Heart Failure quality of life score from 41±19 to 24±17 (P<0.001) compared to baseline. The need for hospital care decreased significantly after biventricular pacing. The total number of hospital days in all patients was 253 the year before compared to 45 the year after biventricular pacing (P<0.01). For heart failure related hospital days the corresponding figures were 183 and 39 days, respectively (P<0.01). Biventricular pacing improved 13/16 patients with severe heart failure and wide QRS complexes in this open study. The improvement resulted in a reduced need for hospital care.

Key Words: Heart failure • Cardiac pacing • Hospitalisations

Received February 15, 2000; Revised May 9, 2000; Accepted June 20, 2000


   1. Introduction
Top
 Abstract
 1. Introduction
2. Methods
 3. Results
 4. Discussion
 References
 
Heart failure is a common condition with an estimated overall prevalence of 1–2%. It increases by age with a marked rise above the age of 60 years [1,2]. The progress in the pharmacological treatment of heart failure has been substantial [3–10]. Nevertheless, the 1-year mortality is still in the order of 10–40% [3–13]. The health care expenditures for heart failure are significant. In Sweden they account for nearly 2% of the health care budget out of which 65–75% are related to hospital care [14,15].

Patients with severe heart failure refractory to drug treatment can be offered heart transplantation or a cardiac assist device as a bridge to transplantation. Such treatment is only available for a limited number of patients. Therefore, there is a clear need for additional treatment options.

It is estimated that 30% of patients with severe heart failure have intraventricular conduction disturbances characterised by wide QRS complexes and a discoordinate ventricular contraction pattern [16–18]. The delay in ventricular electrical activation may be overcome by biventricular pacing. Uncontrolled studies of such pacing demonstrate improvements in central hemodynamics, exercise tolerance and quality of life in patients with severe heart failure and wide QRS complexes [19,20]. Whether such a benefit results in a decreased need for hospital care has not yet been demonstrated.

The aim of this study was to assess whether biventricular pacing affected the total and heart failure related hospital days in severe heart failure patients eligible for biventricular pacing and to evaluate the clinical effects of biventricular pacing.


   2. Methods
Top
 Abstract
 1. Introduction
 2. Methods
3. Results
 4. Discussion
 References
 
All patients were recruited from heart failure clinics. Patients with heart failure due to ischemic heart disease or dilated cardiomyopathy were eligible if they were in New York Heart Association functional class (NYHA class) III–IV despite optimised drug treatment including ACE inhibitors or betablocker in maximal tolerated dosages. For patients intolerant to ACE inhibitors an angiotensin-II receptor antagonist was used. Administration of an aldosterone antagonist was established in only four patients since the results of the RALES study were not published at that time. Patients should be clinically stable at the time of operation and no change of drug treatment was performed for at least 1 month before pacemaker implantation beside some adjustments in diuretic dose. Before inclusion the following baseline data was collected: a 12-lead surface electrocardiogram (ECG), Doppler-echocardiography, a 6-min walk test [21] and quality of life [22,23]. Left ventricular ejection fraction measured by echocardiography had to be less than 40%. The QRS duration should be >150 ms and for those already paced >200 ms. The time of a previous His-ablation due to atrial fibrillation had to exceed 3 months. All patients were examined by a coronary angiogram to rule out a possible need for revascularisation and to establish the anatomy of the coronary sinus prior to pacemaker implantation. Patients were excluded if they had unstable angina, needed revascularisation or if coronary by pass surgery or percutaneous transluminal coronary angioplasty had been performed within the last 6 months. A recent myocardial infarction within the last 3 months was also an exclusion criteria as was the existence of a traditional indication for a pacemaker or an implantable defibrillator. The study was approved by the local Ethics Committee.

2.1. Quality of life
Quality of life was measured with two self-administered Questionnaires, the Minnesota Living With Heart Failure Questionnaire [22] and the Karolinska Questionnaire [23]. The Minnesota is a disease specific form on 21 limitations, frequently associated with heart failure. The response scale for each question ranges between 0 (no limitation) and 5 (very much). It has been proven reliable and has been validated in heart failure patients [24]. A total score ranging between 0 and 105 as well as two subscores, one of physical limitations (8 items, range 0–40) and another on emotional limitations (5 items, range 0–25) can be calculated [24]. For all scores the higher the figure, the worse quality of life.

The Karolinska questionnaire is a quality of life instrument which contains 94 items covering all broad domains of quality of life. It has been validated for patients with bradyarrhythmia and for patients with hypertrophic obstructive cardiomyopathy treated with AV synchronous pacing as described elsewhere [23,25–27]. General quality of life questions concerns physical, social, sexual and cognitive functioning, alertness, sleep, self-perceived health and emotional state. Sixteen questions address cardiovascular symptoms such as chest pain, dyspnea, dizziness and palpitations. A percentual assessment for quality of life parameters was chosen in the presentation of results since the scales differ for the various dimensions.

2.2. Pacemakers and leads
All pacemaker implantations were performed by one of the authors (FG). The left ventricular electrodes (Medtronic 2188, Medtronic 2187, Medtronic Inc Minneapolis, MN, USA) were positioned according to the technique developed by Daubert et al. [28] through the coronary sinus to a lateral or posterolateral vein or to the great cardiac vein. A right ventricular lead was positioned in the right ventricular apex or the right ventricular outflow tract. Four different DDDR pacemakers were used (Thera® DR; InSync® Medtronic Inc. Minneapolis, MN, USA; Chorum®, Ela Medical, France; Affinity®, Pacesetter, St Jude, Veddesta, Sweden).

Two different pacing systems were implanted: a biventricular rate adaptive pacemaker for patients with atrial fibrillation or a biventricular AV synchronous pacemaker for those with sinus rhythm. For those with atrial fibrillation two ventricular leads were implanted and connected to a DDDR device (Thera DR® or Affinity®). The pacemaker was programmed in the DDDR mode with the shortest sensed AV delay 30 ms which here corresponds to the time between the left and right ventricular activation. For patients in sinus rhythm a right atrial lead was also implanted and connected to the atrial port of the pacemaker. The device was programmed to the DDD mode with simultaneous stimulation of both ventricles. The AV delay in patients with sinus rhythm was individually optimised as described by Ritter [29]. The rate limits of the pacemaker were programmed to DDD 50–150 beats/min. For patients who had previously been subject to His-ablation the pacing mode was biventricular DDDR with rate limits 70–150 beats/min.

2.3. Follow-up
The follow-up period was June 1998 to 15 December 1999. Medication for heart failure was maintained unchanged over the study period except for diuretics which were adjusted according to clinical demands. The patients were followed at the outpatient clinic after 1, 6 and 12 months by clinical findings, NYHA class, 12-lead ECG, a technical pacemaker follow-up, 6-min walk test and quality of life. Changes of medication, hospital days and hospitalisations were noted.

2.4. Hospital days, hospitalisations and cost estimations
The need for hospitalisations, all cause and heart failure related hospital days were monitored. These comparisons were based on the same follow-up period after as before the pacemaker implantation in each individual patient for a maximum of 1 year. The hospital records were reviewed by one investigator (FB) to determine the exact cause and duration of the hospital stays. Pacemaker related hospitalisations and hospital days following the primary implantation of the biventricular pacemaker were monitored separately. When the patient was hospitalised due to heart failure as a primary diagnosis, however, with a concomitant pacemaker-related problem an estimate was made of the duration of hospitalisation that related to each of these two reasons. An estimation of all costs relating to the pacemaker procedure, equipment, follow-up and costs due to pacemaker-mediated complications and for hospital care for any reason was made in collaboration with the hospital administration.

2.5. Statistical methods
Results given are mean±S.D. for the group. For paired comparisons of the 6-min walk test and quality of life a Student's t-test was used. For differences in NYHA class the sign test was applied. For hospital days and hospitalisations, median, 25th and 75th percentiles (described here as Q25 and Q75) are also given. Differences in hospital days and hospitalisations were assessed by Wilcoxon's matched-pairs test. Quality of life was assessed by the Statistical Analysis System. A two-tailed P-value of <0.05 was considered statistically significant.


   3. Results
Top
 Abstract
 1. Introduction
 2. Methods
 3. Results
4. Discussion
 References
 
Between June 1998 and May 1999, 16 patients were enrolled in the study after informed consent and a biventricular pacemaker was successfully implanted. The mean follow-up time was 291±76 days ranging between 120 and 365 days. No patient was lost to follow-up. Clinical characteristics are presented in Table 1. Two patients died (no. 5 and 14), 120 and 224 days after biventricular pacemaker implantation due to pneumonia following a hip fracture (no. 5) and progressive heart failure (no. 14). The mean duration of heart failure before inclusion in the study was 3.1±2.8 years. Of 11 patients with ischemic heart disease seven had previous myocardial infarction and six had undergone coronary artery by pass surgery. Three patients had insulin dependent diabetes and two had renal failure indicated by a creatinine value of >130 mmol/l. Apart from three patients who had previously been subject to radiofrequency ablation of the AV node none had a conventional indication for pacing. The mean dose of ACE inhibitors was 84±52 mg for captopril, 17±15 mg for enalapril and 10±0 mg for ramipril, respectively. The mean dose of carvedilol was 26±16 mg and of furosemide 96±62 mg.


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  		Table 1 Patient characteristicsa

 
Thirteen of the 16 patients improved by at least one functional class and were classified as responders (Fig. 1, NYHA class). There were three non-responders (no. 6, 10, 14). Data on the 6-min walk distance and quality of life are provided in Table 2. The Karolinska quality of life results are presented in Fig. 2. Systolic and diastolic blood pressure, resting heart rate and body weight at baseline and during follow-up are presented in Table 3. The duration of the QRS complex was significantly reduced from 181±22 ms at baseline to 152±34 ms during pacing (P<0.01).


Figure 1
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  		Fig. 1 The New York Heart Association Functional Class (NYHA) at baseline and after 1 and 6 months of biventricular pacing.

 


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  		Table 2 Minnesota Living with Heart Failure scores and 6-min walk distance (m) at baseline and after 1 and 6 months of biventricular pacing

 


Figure 2
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  		Fig. 2 Percentual change in selected features of quality of life as assessed by the Karolinska Quality of Life Questionnaire after 1 (dark bars) and 6 months (light bars) of biventricular pacing compared to baseline. n.s.; not significant *P<0.05; **P<0.01; ***P<0.001.

 


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  		Table 3 Blood pressure, resting heart rate and body weight at baseline and 1 and 6 months after biventricular pacinga

 
3.1. Pacemaker implantation
The mean operation time was 71±30 min and the mean fluoroscopy time 27±19 min. The left ventricular lead position was the coronary sinus lateral or posterolateral branch stimulation site (n=12) or great cardiac vein site (n=4). Due to early dislodgement it had to be repositioned three times in one patient (no. 5) and once in another subject (no. 14). In patient no. 5 each loss of left ventricular stimulation was followed by symptoms of worsening heart failure. The right ventricular lead was positioned in the right ventricular apex (n=2) and the right ventricular outflow tract (n=14). The patients were hospitalised 2.5±0.7 days for the pacemaker implantation. The pacemaker follow-up revealed stable left ventricular stimulation thresholds over time.

3.2. Hospital days and hospitalisations
Total and heart failure related hospital days and hospitalisations are presented in Table 4. Individual hospital consumption the year before and after biventricular pacing is given in Fig. 3a,b.


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  		Table 4 Total and heart failure related hospital days and hospitalisations before and after biventricular pacinga

 


Figure 3
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  		Fig. 3 The total number of hospital days for any reason (a) and the number of hospital days for heart failure (b) in each individual (nos. 1–16) before (left of vertical line) and after biventricular pacing (right of vertical line). In each patient the number of hospital days during the time with biventricular pacing is compared to those occurring during the corresponding time before biventricular pacing was started. The crosses indicate patients who died during follow up.

 
In addition there were 40 and 9 hospital days related to pacemaker implantation and pacemaker related complications, respectively. Complications occurred in three patients and were constituted by dislodgement of the left ventricular lead in two cases (see above) and hematoma in the pacemaker pocket in one subject. The estimated costs for hospital care, pacemaker implantation and follow-up and complications are shown in Table 5.


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  		Table 5 Estimated costs for hospital care and pacemaker related costs in 16 patients before and after biventricular pacing (BiV)a

 

   4. Discussion
Top
 Abstract
 1. Introduction
 2. Methods
 3. Results
 4. Discussion
References
 
This study to our knowledge is the first to demonstrate a reduction in the need for hospitalisations and hospital days in parallel to clinical improvements by biventricular pacing in selected patients with severe heart failure.

Biventricular pacing has recently emerged as a treatment alternative in patients with severe heart failure and intraventricular conduction disturbances. To date, there are no available reports on changes in the consumption of hospital care following such treatment. Biventricular pacing was first suggested by Bakker et al. [30]. Available reports mainly focused on short-term hemodynamic benefits, functional class, quality of life and submaximal exercise tolerance but not on the need for hospital care [19,20,31–33].

In the present study 13 of 16 patients improved by at least one functional class after biventricular pacemaker implantation. Importantly, dislodgement of the coronary sinus lead in one patient (no. 5) was accompanied by clinical deterioration, which was reversed upon repositioning of the lead. The magnitude of improvement in this study corresponds with previous observations [19,20,30] with a 16% increment in 6-min walk distance and an improvement by at least one NYHA class. Quality of life by a method well validated for heart failure patients [24] improved by 41% after 6 months compared to baseline. In comparison, a 17% improvement in total score of the Minnesota Living with Heart Failure Questionnaire was described in the SOLVD treatment trial [34]. Improvements of similar degree as by the Minnesota form, were noted by the Karolinska quality of life form used elaborated for paced patients. The improvements by this instrument were of similar level as previously described in patients paced due to hypertrophic obstructive cardiomyopathy [26,35]. Not surprisingly, the degree of improvement was more pronounced after 1 compared to 6 months. This probably reflects the placebo effect by pacemaker implantation previously described by us [35,36]. In agreement with our present and previous observations this placebo effect wanes with time.

In this study and in agreement with previous studies, it is clear that not all heart failure patients respond to biventricular pacing. Three patients were not improved. In one (no. 14) right ventricular heart failure was more pronounced than left ventricular failure. Although not described in the literature, it is our clinical experience that biventricular stimulation is not efficacious in patients mainly afflicted with right ventricular failure. In another (no. 10) pulmonary disease probably constituted a greater limitation than heart failure. The third patient (no. 6) had suffered several previous infarctions. It is possible that left ventricular stimulation, in this case by the great cardiac vein, was not optimal and that pacemaker stimulation of viable myocardium was not achieved.

ACE inhibitors have been shown to improve mortality and morbidity in severe, moderate heart failure and in asymptomatic left ventricular dysfunction [3–6]. Betablockers further reduce mortality and morbidity [7–9]. In this study all patients were carefully optimised on drug treatment in a stable dose at least 1 month before the study started. Aldosterone-antagonists were not uniformly prescribed since the clear evidence for a benefit as indicated by the RALES study was not available [10]. Thereafter the drug regimen was not changed unless by clinical necessity such as exacerbation of heart failure. Such changes were made in four patients only. Therefore, we believe that the changes found can be attributed to the pacemaker treatment.

In this study the clinical improvements in 6-min walk test and quality of life occurred in parallel with a significant reduction in total and heart failure related hospital days and hospitalisations. In some patients the results were striking, decreasing hospital days from 92 days to none over a period of 10 months of biventricular pacing (Fig. 3a,b).

In heart failure management it is essential to bring down the costs for hospital care. Recent studies indicate that a comprehensive heart failure care program can reduce the need for hospital care [37]. In this study all subjects were recruited from such programs and nevertheless had required a substantial amount of hospital care. We therefore believe that biventricular pacing rather than frequent follow-up was the reason for the improvements observed. Pacemaker therapy is not an inexpensive treatment and comprises costs for equipment, implantation procedure and follow-up. Although the morbidity by pacemaker implantation in this study was greater than by conventional pacemaker implantation, the need for hospital care due to pacemaker-related complications was relatively small. The small number of patients does not justify more extensive cost–benefit analysis. Nevertheless, the total costs for pacemaker implantation and follow-up equalled the difference in costs for hospital care the year before and after biventricular pacing. It is important to remember that it is hard to prove the cost effectiveness of a novel treatment before it has been properly elaborated. Therefore, we believe that the pacemaker related costs in this study were justifiable in view of the ongoing elaboration and assessment of this treatment [38]. In the future, costs for biventricular pacing might be reduced due to simplification of the left ventricular lead technology and increased knowledge of how to select suitable patients for this intervention. Nevertheless, these findings do indicate that biventricular pacing might reduce the costs for hospital care in selected patients with severe heart failure at least over the first year. This treatment therefore can serve as a bridge to heart transplantation in those eligible and improve the well being and reduce costs for hospital care in these severely incapacitated patients.

4.1. Limitations
The interpretation of our results is limited by the uncontrolled design of the study and the small number of patients. Larger controlled studies are under way and will add valuable information to the issues discussed above [38].

4.2. Conclusion
In this open study with a mean follow-up time of 291 days biventricular pacing improved NYHA class, 6-min walk test and quality of life significantly in 13 of 16 patients with severe heart failure and wide QRS duration. The clinical improvement was accompanied by a significantly reduced need for hospital care.


   Acknowledgements
 
Supported by the Swedish Heart and Lung Association, the Swedish Medical Research Council (grant no B96-11626-01). We thank Mr Stig Elofsson for expert statistical advice.


   References
Top
 Abstract
 1. Introduction
 2. Methods
 3. Results
 4. Discussion
 References
 

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A. Bundkirchen and R. H.G Schwinger
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C. Linde, C. Leclercq, S. Rex, S. Garrigue, T. Lavergne, S. Cazeau, W. McKenna, M. Fitzgerald, J.-C. Deharo, C. Alonso, et al.
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