Correspondence

Defibrillators in Heart Failure and Quality of Life

N Engl J Med 2009; 360:187-189January 8, 2009

Article

To the Editor:

Mark et al. (Sept. 4 issue)1 report data on quality of life from the well-designed Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT). These data call for a repeat cost-effectiveness analysis of the use of implantable cardioverter–defibrillators (ICDs) for the primary prevention of death from cardiac causes. The newly reported utilities were 0.80 at baseline and 0.70 at 30 months. Mark et al. did not report these utilities in their previous cost-effectiveness analysis.2 In contrast, a separate cost-effectiveness analysis assumed a utility of 0.88 and showed ICDs to be cost-effective.3 The application of these new utilities to the sensitivity analysis of this second cost-effectiveness analysis would correspond to a cost-effectiveness ratio somewhere between $150,000 and more than $400,000 per quality-adjusted life-year.

In addition, although the authors report that overall quality of life was not affected by the ICD, quality of life did decrease in patients who received a shock. At 12 months, quality of life was not different in the patients who received a shock, but these results must be interpreted cautiously, since more than half of the patients who received a shock had died by this time.4 In other words, the ICD does not decrease quality of life unless it actually works.

Dan D. Matlock, M.D.
University of Colorado Denver School of Medicine, Denver, CO 80045
daniel.matlock@uchsc.edu

4 References

1. 1

   Mark DB, Anstrom KJ, Sun JL, et al. Quality of life with defibrillator therapy or amiodarone in heart failure. N Engl J Med 2008;359:999-1008
   Full Text | Web of Science | Medline

2. 2

   Mark DB, Nelson CL, Anstrom KJ, et al. Cost-effectiveness of defibrillator therapy or amiodarone in chronic stable heart failure: results from the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT). Circulation 2006;114:135-142
   CrossRef | Web of Science | Medline

3. 3

   Sanders GD, Hlatky MA, Owens DK. Cost-effectiveness of implantable cardioverter-defibrillators. N Engl J Med 2005;353:1471-1480
   Full Text | Web of Science | Medline

4. 4

   Poole JE, Johnson GW, Hellkamp AS, et al. Prognostic importance of defibrillator shocks in patients with heart failure. N Engl J Med 2008;359:1009-1017
   Full Text | Web of Science | Medline

To the Editor:

Mark et al. evaluated quality of life in patients treated with ICDs as compared with optimal medical management. However, the outcomes measured in this study may not capture important psychosocial factors such as anxiety or the effect of a preexisting psychiatric diagnosis.

A limited number of studies suggest that ICD implantation and subsequent shocks may exacerbate symptoms of anxiety, fear, and agoraphobia.1,2 Although Mark et al. report that data provide some support for the use of ICDs in patients with severely reduced systolic dysfunction, none of the outcome measures specifically addressed fear, anxiety, or both. We wonder whether anxiety-specific instruments such as the State–Trait Anxiety Index were included in the structured interviews.

There may be an increased risk of psychosocial dysfunction among patients with preexisting psychiatric diagnoses who undergo ICD implantation.3 In order to assess the generalizability of these data to populations with a higher prevalence of coexisting psychiatric conditions, it would be helpful to know about the baseline prevalence of psychiatric illness in the study by Mark et al.

Robin M. Telerant, M.D.
Nathan Boyer, M.D.
Devan Kansagara, M.D.
Oregon Health and Sciences University, Portland, OR 97239
telerant@ohsu.edu

3 References

1. 1

   Burke JL, Hallas CN, Clark-Carter D, White D, Connelly D. The psychosocial impact of the implantable cardioverter defibrillator: a meta-analytic review. Br J Health Psychol 2003;8:165-178
   CrossRef | Web of Science | Medline

2. 2

   Godemann F, Butter C, Lampe F, et al. Panic disorders and agoraphobia: side effects of treatment with an implantable cardioverter/defibrillator. Clin Cardiol 2004;27:321-326
   CrossRef | Web of Science | Medline

3. 3

   Sears SF, Lewis TS, Kuhl EA, Conti JB. Predictors of quality of life in patients with implantable cardioverter defibrillators. Psychosomatics 2005;46:451-457
   CrossRef | Web of Science | Medline

To the Editor:

In their article on health-related quality of life with ICD therapy, Mark et al. found that primary-prevention ICDs do not adversely affect health-related quality of life. Their findings extended our previous observations from the Defibrillators in Nonischemic Cardiomyopathy Treatment Evaluation (DEFINITE) trial, which involved ICD recipients with nonischemic cardiomyopathy, to include patients with ischemic disease.1 However, the infrequent quality-of-life assessments performed in SCD-HeFT and the comparison with a single measurement before the shock occurred raise questions regarding whether the observed changes were the result of progression of heart failure or the deleterious effects of shocks.2 In contrast, the more frequent assessments performed in the DEFINITE trial allowed for the analyses of trajectories of quality of life within each individual patient before and after the shock occurred, thus determining that the observed changes were from shocks themselves. We therefore believe that the issue of whether ICD shocks in patients with ischemic cardiomyopathy independently worsen quality of life remains unresolved. Furthermore, clinical strategies aimed at reducing shocks remain a critical tactic to prevent unnecessary distress and increase acceptance of this lifesaving therapy.3,4

Rod Passman, M.D., M.S.C.E.
Alan Kadish, M.D.
Northwestern University Feinberg School of Medicine, Chicago, IL 60611-2908
r-passman@northwestern.edu

Sam Sears, Ph.D.
East Carolina University, Greenville, NC 27858-4353

Dr. Passman reports receiving fees and grant support from Medtronic; and Dr. Kadish, receiving grant support from Medtronic and St. Jude Medical. No other potential conflict of interest relevant to this letter was reported.

4 References

1. 1

   Passman R, Subacius H, Ruo B, et al. Implantable cardioverter defibrillators and quality of life: results from the Defibrillators in Nonischemic Cardiomyopathy Treatment Evaluation (DEFINITE) study. Arch Intern Med 2007;167:2226-2232
   CrossRef | Web of Science | Medline

2. 2

   Whang W, Mittleman MA, Rich DQ, et al. Heart failure and the risk of shocks in patients with implantable cardioverter defibrillators: results from the Triggers Of Ventricular Arrhythmias (TOVA) study. Circulation 2004;109:1386-1391
   CrossRef | Web of Science | Medline

3. 3

   Wathen MS, DeGroot PJ, Sweeney MO, et al. Prospective randomized multicenter trial of empirical antitachycardia pacing versus shocks for spontaneous rapid ventricular tachycardia in patients with implantable cardioverter-defibrillators: Pacing Fast Ventricular Tachycardia Reduces Shock Therapies (PainFREE Rx II) trial results. Circulation 2004;110:2591-2596
   CrossRef | Web of Science | Medline

4. 4

   Wilkoff BL, Williamson BD, Stern RS, et al. Strategic programming of detection and therapy parameters in implantable cardioverter-defibrillators reduces shocks in primary prevention patients: results from the PREPARE (Primary Prevention Parameters Evaluation) study. J Am Coll Cardiol 2008;52:541-550
   CrossRef | Web of Science | Medline

Author/Editor Response

I must correct some inaccurate impressions presented in Matlock's letter. First, we did use time–trade-off utility weights to calculate the cost-utility ratio for ICD therapy in the SCD-HeFT in a previous publication.1 Second, as reported in that publication, the time–trade-off utility for 30 months was 0.85, and not 0.70 as Matlock writes. Third, the calculation Matlock offers based on the article by Sanders et al. is incorrect and misleading, since it assumes a differential utility between the two groups that was not empirically observed. Finally, of the 49 patients with a quality-of-life assessment within 30 days after an ICD shock, 4 died in the year after the shock.

With regard to the question by Telerant et al. about additional psychosocial measures in patients with an ICD, more detailed data including measures of anxiety and depression would be useful.

I agree with Passman et al. that it is extremely difficult to know whether the decreased quality of life seen soon after ICD shocks is due to the shock itself, changes in the underlying cardiac disease, or both. Although DEFINITE did perform quality-of-life assessments every 3 months, quality-of-life data were missing for a large number of subjects in this substudy, and the effect of these missing assessments on the results of the study analyses is difficult to judge. Furthermore, changes in clinical status in heart failure may occur over a shorter time frame than 3 months, so it is unclear that such data would really be able to settle the cause-and-effect question regarding ICD shocks and quality of life.

Daniel B. Mark, M.D., M.P.H.
Duke University Medical Center, Durham, NC 27705

1 References

1. 1

   Mark DB, Nelson CL, Anstrom KJ, et al. Cost-effectiveness of defibrillator therapy or amiodarone in chronic stable heart failure: results from the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT). Circulation 2006;114:135-142
   CrossRef | Web of Science | Medline