© 2004 by European Society of Cardiology
EDITORIAL
From trials to guidelines to clinical practice: the need for improvement
Molecular Cardiology, IRCCS Fondazione Maugeri, Department of Cardiology, University of Pavia Via Ferrata 8, 27100 Pavia, Italy
Manuscript submitted 7 January 2004. Tel.: +39-0382-592-051; fax: +39-0382-592-059. E-mail address: spriori{at}fsm.it.
In this issue of the journal, Sterk et al. [1]
present a study that retrospectively analyses the management of individuals surviving out-of-hospital cardiac arrest. The objective of the study is to assess whether information derived from clinical trials and incorporated into guidelines is applied in the clinical setting, and whether these sources provide adequate information to decide upon the use of an ICD in most cardiac arrest survivors. The authors conclude that in approximately 20% of individuals who survived cardiac arrest and were discharged alive from hospital, the clinical assessment was not adequate conclusively to decide whether, according to guidelines [2–5], an ICD was indicated, and the authors therefore support the view that efforts should be made to reduce the gap between guidelines and practice.
The data reported in this study prompt broader considerations pertaining to survival after cardiac arrest that may influence the strategies adopted to fight sudden cardiac death. Sterk et al. [1] report that in a period of 25 months in an area inhabited by 1.6 million people they identified "only" 372 cardiac arrests with documented ventricular fibrillation. Based on the accepted prevalence of cardiac arrest in the western population of 1/1000 per year [6], one may estimate that 3200 sudden cardiac deaths occurred in the two-year period in the region in which the study was conducted. This means that most of the victims of sudden cardiac death are missed and are not rescued by the emergency medical teams. Even more impressive is the finding that only 70 of the 372 patients were discharged alive from the hospital. These numbers reveal that the problems of management of survivors of cardiac arrest are relevant to a very small percentage of the individuals who experience cardiac arrest. Obviously, this means that while we should continue to struggle to optimise the management of these survivors, we should also acknowledge that secondary prevention of cardiac arrest (i.e. that focussed on individuals who survived a first episode) is not enough to have a real impact on mortality and morbidity of sudden cardiac death and that primary prevention of cardiac arrest must become the target.
The key finding of the study by Sterk and co-workers [1] is provided by the evidence that, despite guidelines produced by different scientific societies agreeing on recommendations, cardiologists still fail adequately to investigate survivors of out-of-hospital cardiac arrest. This observation raises interest in defining the causes of this lack of compliance with guidelines. Unfortunately, the Sterk et al. study [1] was not designed to investigate these reasons leaving us to speculate on the likely explanations for the gap between recommendations and practice. It is possible that physicians were not aware of the guidelines; however, this seems rather unlikely considering that for 80% of patients the management strategy was in agreement with evidence-based recommendations. It would have been extremely valuable if the authors had had the opportunity of investigating if difference existed in the characteristics of the hospital settings in which patients were managed in agreement with guidelines and those where they were not. It may be too simple to believe that the dissemination of guidelines through meetings, journals, slides, etc is enough to align practice with recommendations. Economic and logistic factors may turn out to be the real barriers to the implementation of guidelines. For example, it would have been interesting to know if programmed electrical stimulation for risk stratification for applying the recommendations based on MUSTT [7] and the MADIT [8] trials was omitted in those hospitals in which there was no electrophysiology laboratory. It seems, in fact, reasonable to assume that the adoption of novel schemes for clinical practice will require not only the intellectual effort of "learning" the new diagnostic and therapeutic modalities but also the "structural" change of creating an environment within the hospital in which the new schemes for patient management can be applied.
Some consideration should therefore be given to the methodology used for the development of guidelines and their implementation. A general consensus has been reached that recommendations for clinical practice should be based on the evidence derived from clinical trials, where available. Accordingly, assessment of the methodological characteristics of a trial, including the study design, patient selection, the strength of the results, and their applicability to clinical practice, are the fundamental steps in the development of guidelines that represent therefore a critical appraisal of the evidence published in the medical literature on a specific topic and should be performed by individuals with medical, scientific, statistical competence [9]. This step should be independent from economical considerations that will have to be addressed by a wider group of experts and be tailored not only to the different medical systems but also to the available resources. It is, however, clear that in order to make guidelines become part of medical practice they should be disseminated and at the same time medical systems should allow their implementation by accepting reimbursement of novel therapies supported by strong recommendations. The accomplishment of this latter step is of fundamental importance to ensure that patient care is constantly updated to incorporate medical innovations. However, the constantly increasing costs of care represent a major obstacle to the acceptance of new recommendations by medical systems. Therefore, each country should carefully establish its own medical priorities proportional to the available resources and the local medical community should have an active part in collecting the epidemiological data that provide the substrate on which the local priorities for health care expenditure are based.
In their study, Sterk et al. [1] identify another interesting aspect that contributes to separation of practice from guidelines when they point to the fact that even the best recommendations for practice are not comprehensive and do not provide guidelines for the management of all patients. These "grey areas" in the recommendations for treatment are represented by patient subgroups for whom "evidence" on the efficacy of therapy or on the risk of death is lacking. Specifically, Sterk et al. [1] point to the difficulties encountered in practice when trying to apply the definition of transient, reversible, or treatable causes of VF as a contraindication to the use of an ICD in survivors of cardiac arrest. It is clear that if a cause of cardiac arrest can be identified and treated (for example, hypokalemia or drug-induced Torsade des Pointes degenerating into ventricular fibrillation) it is inappropriate to implant such patients with an ICD. Obviously, the best preventive measure for recurrence of cardiac arrest would be the avoidance of the triggering factor. However, reality may provide less straightforward scenarios. As Sterk et al. [1] suggest, the occurrence of ventricular fibrillation during an acute ischaemic episode may be considered as an arrhythmic event that can be prevented by abolishing or attenuating myocardial ischaemia. Yet it is also possible that an ischaemic episode resulting in cardiac arrest may be the indicator of electrical instability that is simply unmasked by the ischaemia, which may persist after revascularization and/or anti-ischaemic treatment. How to assess the residual risk of recurrence of cardiac arrest in these patients is poorly defined because "evidence" from clinical trials is not available. This consideration prompts some important considerations that pertain to the design and funding of clinical trials. Most trials are supported by industry, which is willing to invest only in a limited number of studies, and public funding for large trials is inadequate to address most of the questions remaining unanswered. The overall effect is limitation of the possibility of developing guidelines for the management of specific subgroups of patients [10]. Thus, it is possible that even after successful education of physicians on the recommendations provided by guidelines and after approval of reimbursement of novel drugs and devices it would still be impossible to treat all patients according to "evidence-based guidelines" because data on the risk of recurrent cardiac arrest are available only for the limited group of patients who have been included in clinical trials.
It is therefore clear that while there is agreement that a gap exists between guidelines and practice, few studies have specifically addressed the reasons for the gap and therefore corrective measures can only be empirical. In this respect it would be important to conduct a survey, like the one performed by Sterk and colleagues [1], in a larger population. Such a study would attempt to assemble causes of lack of adherence to guidelines and to characterize better the subgroups of cardiac arrest survivors in which evidence-based recommendations for management are not available. This should result in the planning of specific studies to fill the gap between science and guidelines.
As a final consideration it is important to encourage funding agencies and medical journals to give higher priority to studies performed on an unselected population of patients that really reflect clinical practice. These studies/surveys are often considered less informative than the methodologically rigorous trials while they should be regarded as equally important as more focussed trials in achieving the final goal of medical research, improvement of patient care.
References
[1] Sterk B, van Alem AP, Tukkie R, Simmers TA, Koster RW. ICD-implantation guidelines versus clinical practise: a prospective study of out-of-hospital cardiac arrest survivors. Europace 2004; 6: (in press).
[2] Priori SG, Aliot E, Blomstrom-Lundqvist C, Bossaert L, Breithardt G, Brugada P, et al. Task force on sudden cardiac death of the European Society of Cardiology. Eur Heart J 2001; 22: 1374–1450.
[3] Hauer RN, Aliot E, Block M, Capucci A, Luderitz B, Santini M, et al. Indications for implantable cardioverter defibrillator (ICD) therapy. Europace 2001; 3: 169–176.
[4] Gregoratos G, Cheitlin MD, Conill A, Epstein AE, Fellows C, Ferguson TB Jr., et al. ACC/AHA guidelines for implantation of cardiac pacemakers and antiarrhythmia devices: executive summary—a report of the American College of Cardiology/American Heart Association Task Force on practice guidelines (Committee on Pacemaker Implantation). Circulation 1998; 97: 1325–1335.[Medline]
[5] Schalij M, Blom N, Dijkamn B, et al. Richtlijn ICD-implantaties 2000. Cardiologie 2001; 8: 52–66.
[6] Gorgels AP, Gijsbers C, de Vreede-Swagemakers J, Lousberg A, Wellens HJ. Out-of-hospital cardiac arrest—the relevance of heart failure. The Maastricht Circulatory Arrest Registry. Eur Heart J 2003; 24: 1204–1209.
[7] Buxton AE, Lee KL, Fisher JD, Josephson ME, Prystowsky EN, Hafley G. A randomized study of the prevention of sudden death in patients with coronary artery disease. Multicenter Unsustained Tachycardia Trial Investigators. N Engl J Med 1999; 341: 1882–1890.
[8] Moss AJ, Hall WJ, Cannom DS, Daubert JP, Higgins SL, Klein H, et al. Improved survival with an implanted defibrillator in patients with coronary disease at high risk for ventricular arrhythmia. Multicenter Automatic Defibrillator Implantation Trial Investigators. N Engl J Med 1996; 335: 1933–1940.
[9] Priori SG, Klein W, Bassand JP. Medical practice guidelines. Separating science from economics. Eur Heart J 2003; 24: 1962–1964.
[10] Bassand JP, Martin J, Rydén L, Simoons M. European Society of Cardiology. The need for resources for clinical research: the European Society of Cardiology calls for European, International collaboration. Lancet 2002; 360: 1866–1869.[CrossRef][Web of Science][Medline]
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