CORRESPONDENCE: LETTER TO THE EDITOR
No Benefit From Cardiac Resynchronization Therapy in Asymptomatic Patients
Stefan Osswald, MD*,
Beat Schaer, MD,
Michael Kuhne, MD and
Christian Sticherling, MD
* Head Cardiac Arrhythmia Service, University Hospital Basel, CH-4031 Basel, Switzerland (Email: sosswald{at}uhbs.ch).
We congratulate Linde et al. (1) on the meticulously carried out REVERSE (REsynchronization reVErses Remodeling in Systolic left vEntricular dysfunction) trial that addressed the question of the clinical benefit of cardiac resynchronization therapy (CRT) in patients with New York Heart Association (NYHA) functional class II and I heart failure (1). Unfortunately, the composite primary end point as defined per the study protocol was negative. Still, the authors conclude that CRT, in combination with optimal medical treatment (± defibrillator), reduces the risk for heart failure hospitalizations and improves ventricular structure and function in NYHA functional class II and I. In our opinion, the later statement is not supported by the presented data, which shows no benefit for NYHA functional class I patients (odds ratio: 0.87; 95% confidence interval: 0.37 to 2.03) in their subgroup analysis (Fig. 4 of Linde et al. [1]).
This disagreement raises the more philosophical question: whether these subgroup analyses make sense if the primary end point is negative—maybe due to a lack of statistical power? It seems that the well-known players such as wide QRS and low left ventricular ejection fraction are positive predictors for CRT success but not NYHA functional class I. Another intriguing finding of this subgroup analysis is that patients on diuretics did improve, whereas those not on diuretics did not. However, the use of diuretics reduced mortality and prevented hospital admissions in this patient population, which raises the question of whether the use of diuretics by themselves may have accounted for the documented beneficial effect (clinical composite end point, hospitalizations) in the CRT ON group and whether this confounding variable was corrected for in the main analysis (2).
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1. Linde C, Abraham WT, Gold MR, St John Sutton M, Ghio S, Daubert C, REVERSE (REsynchronization reVErses Remodeling in Systolic left vEntricular dysfunction) Study Group Randomized trial of cardiac resynchronization in mildly symptomatic heart failure patients and in asymptomatic patients with left ventricular dysfunction and previous heart failure symptoms J Am Coll Cardiol 2008;52:1834-1843.[Abstract/Free Full Text]2. Faris R, Flather, MD, Purcell H, Poole-Wilson PA, Coats AJ. Diuretics for heart failure Cochrane Database Syst Rev 2006CD003838.[CrossRef][Web of Science][Medline]
Related Article
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- Cecilia Linde, William T. Abraham, Michael R. Gold, Martin St John Sutton, Stefano Ghio, Claude Daubert REVERSE Study Group
J. Am. Coll. Cardiol. 2009 53: 2198-2199.
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