Reply: Global health resource utilization associated with pacemaker complications

We read with interest the paper “Global health resource utilization associated with pacemaker complications” by Waweru et al. Cardiac implantable electronic devices (pacemakers, defibrillators, resynchronization systems) are expensive medical treatments, with demand rising as an increasingly elderly population meet clinical criteria and, therefore, drive spending. Re-operation is an inevitable and costly outcome as a consequence of the finite lifespan of manufactured goods (battery longevity, mechanical stress resulting in lead failure). Whilst attempting to advance knowledge on the cost of complications, Waweru et al. simply produce a consensus opinion on the clinical management of poorly defined complication scenarios, through re-surveying a self-selected group until agreement was finally achieved. Participants were selected by Medtronic, with frequently only one, perhaps unrepresentative, individual representing the views of an entire country. No attempt was made to generate an impartial and more representative sample set, thus limiting generalizability to the real world. Selection bias can simply combine the opinions of like-minded clinicians, who may not be representative of the broader clinical group, sampling the views of operators from large centers who treat a complex case-mix with expensive technology which may not be available to all. The snow ball method of recruiting panel members potentially further limits variation in clinical practice, as clinicians whom know each other are likely to have similar views, through previously sharing best practice knowledge and experience. The scenarios considered lack clarity, specifically with respect to implant duration and patient age, which influence procedure complexity, decision-making processes (equipment, personnel, time, complications, hospital stay), and resultant cost. Regarding the upper limb thrombosis scenario, the reader is left to decide whether this is an incidental asymptomatic finding, symptomatic patient or obstruction detected at a lead revision or upgrade procedure, each necessitating a different management strategy. Left upper limb thrombosis has been reported in 4.4–13.7% of patients before a virgin implant, increasing to 14–64% post implant, yet infrequently symptomatic. This emphasizes outpatient anticoagulant therapy without re-operation is an accepted cost-effective approach, without significant morbidity. Lead revisions and infections, particularly systemic infection or endocarditis, are the most resource intensive complications as they necessitate repeat operations (equipment, personnel, time, hospitalization). These complications can arise at any time post-implant, but there is a higher incidence after generator replacement or upgrade procedures. The estimated battery longevity of 12 years described in the study is generous and, if factorized into cost calculations, would under-estimate this potential cost. Infections can be local, systemic, or endocarditis with different cost implications for antibiotics (route, duration, type), re-implantation timing, and length of hospital admission, but these sub-divisions were not separately considered in the study design. Finally, the paper fails to take account of the additional costs generated during hospital visits in the pre-operative work up of these cases (laboratory and radiographic investigations, physiological diagnostics). Waweru et al. have demonstrated an efficient way to converge opinions on the management of clinical cases across the world; however, the sample selection, panel size, and inadequate scenario descriptions diminish the general applicability of their analysis. As such, their analysis fails to generate sufficiently accurate information on healthcare resource use to then be extrapolated to estimate the cost of such complications on a global basis. Obtaining real world retrospective data is time and labour intensive, but accurately reflects real world clinical practice. The development of a prospective, longitudinal registry of all visits, procedures, and equipment itemized to generate accurate individual patient costings is necessary to provide accurate device-related complication costs. Whilst being a comparatively costly undertaking in relation to the approach of Waweru et al. it would be both more accurate and more generalizable to a global clinical setting.