CARDIAC PACEMAKERS

Abstract

Objective: The rise in the number of implantations of cardiac pacemakers is of some concern to decision makers in the health sector. We assessed the intrinsic and relative clinical efficacy of cardiac pacemakers in current clinical indications to find out whether scientific or clinical arguments might justify differences in market prices.

Methods: We retrieved papers on cardiac pacing (January 1993–April 1998) from five databases (MEDLINE, HealthSTAR, EMBASE, Cochrane Library, and PASCAL). The citations in these papers were used to seek further articles. We selected the articles that met the criteria of evidence-based medicine (EBM) (randomized and nonrandomized controlled trials) and classified them according to clinical indication and type of evaluation (either of the intrinsic efficacy of a pacemaker versus a control or of the relative efficacy of different pacing modes).

Results: A total of 542 references were retrieved, but under 10% met our EBM criteria. Very few were comparative studies versus controls; most were recent and tended to use endpoints other than survival. Clinical efficacy was not proven on the basis of EBM criteria, even in common indications (e.g., sick sinus syndrome). Studies comparing different pacing modes were rarely randomized and did not provide consistent evidence for the superiority of any pacing mode in a given indication.

Conclusions: Knowledge of the natural history of the diseases for which cardiac pacing is indicated is scarce. There is an approximately 20-year gap between technological progress and clinical evaluation that cannot be easily bridged because of methodologic difficulties and ethical issues. Current guidelines on pacemaker use either rely on expert opinion or highlight present inadequacies and make recommendations for future work. Available clinical efficacy data do not justify the wide differences in the price of cardiac pacemakers.