JACC VOL. 66, NO. 6, 2015
Letters
AUGUST 11, 2015:754–60
on the patient’s vulnerability—which is often neglec-
As the authors noted, it has already been indi-
ted in our considerations of patients’ risk of adverse
cated that the incidence of musculoskeletal pain is
events. The “protecting” effect of dense calcium
associated with higher case volumes and more years
found by Criqui et al. (4) indeed may be interpreted as
in practice for interventional cardiologists. In other
a marker for individuals who are resistant to vascular
words, the total time exposed to a radiation-bearing
thrombosis in response to plaque ruptures and thus
lead apron might lead to increased risk of musculo-
exhibit more features of plaque healing/organization
skeletal pain. Therefore, it is essential to investigate
in the absence of events. The PESA (Progression of
the association between the total radiation exposure
Early Subclinical Atherosclerosis) study found sub-
time (self-reported exposure time per week years in
clinical atherosclerotic disease in 63% of participants
the current profession) and the proportion of work-
within a middle-aged cohort (5). The discussion on
related pain. Similarly, the association between the
risk assessment in patients warrants a broader,
total time of wearing a lead apron (time per week
comprehensive view rather than focusing on indi-
years in the current profession) and the proportion of
vidual plaque components.
work-related pain also should be analyzed. Unfortunately, years in current profession was not integrated
*Armin Arbab-Zadeh, MD, PhD, MPH Valentin Fuster, MD, PhD
into the analysis when the authors investigated the
*Division of Cardiology
As a result, this led to some cumbersome and feeble
Johns Hopkins University
explanations, such as constant and different physical
600 North Wolfe Street, Halsted 559
stress to argue why nonphysician employees in the
Baltimore, Maryland 21287
interventional lab reported a higher prevalence of
E-mail:
[email protected] work-related musculoskeletal pain, even if they were
http://dx.doi.org/10.1016/j.jacc.2015.06.011
younger with fewer working years. If the authors
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose. Peter Libby, MD, served as Guest Editor for this paper.
investigated the association between musculoskeletal
factors associated with increase of work-related pain.
pain and the total time the catheterization lab operators and staff wore a radiation-bearing lead apron,
REFERENCES 1. Baber U, Mehran R, Sartori S, et al. Prevalence, impact, and predictive value of detecting subclinical coronary and carotid atherosclerosis in asymptomatic adults: the BioImage study. J Am Coll Cardiol 2015;65:1065–74. 2. Puchner SB, Liu T, Mayrhofer T, et al. High-risk plaque detected on coronary CT angiography predicts acute coronary syndromes independent of significant stenosis in acute chest pain: results from the ROMICAT-II trial. J Am Coll Cardiol 2014;64:684–92. 3. Stone GW, Maehara A, Lansky AJ, et al. A prospective natural-history study of coronary atherosclerosis. N Engl J Med 2011;364:226–35. 4. Criqui MH, Denenberg JO, Ix JH, et al. Calcium density of coronary artery plaque and risk of incident cardiovascular events. JAMA 2014;311:271–8. 5. Fernandez-Friera L, Penalvo JL, Fernandez-Ortiz A, et al. Prevalence, vascular distribution, and multi-territorial extent of subclinical atherosclerosis in a middle-aged cohort: the PESA (Progression of Early Subclinical Atherosclerosis) study. Circulation 2015;131:2104–13.
they might have been to obtain evidence to clarify the issue. Moreover, it might have been more interesting to investigate whether there is any correlation between the pain score and the total time of wearing a lead apron in participants exposed to radiation without taking a pain medication. In this cross-sectional case-control study, the authors identified no difference in cancer prevalence between groups (9% vs. 9%; p ¼ 0.96). We suspect a significant bias within this analysis because many staff involved in procedures with radiation exposure had fewer working years and less cancer risk, exhibiting a linear/linear-quadratic, no-threshold radiation relationship with stochastic effects (2). Thus, the comparison of cancer prevalence between groups should be stratified by the working years.
Musculoskeletal Pain and Cancer Risk of Staff Working With Fluoroscopically Guided Procedures
Guoxin Fan, MD *Shisheng He, MD Zhengqi Chen, MD *Orthopedic Department Shanghai Tenth People’s Hospital Tongji University School of Medicine 301 Yanchang Road Shanghai 200072
We took great interest in the paper by Orme et al. (1)
China
recently published in the Journal; however, we have
E-mail:
[email protected] some concerns regarding the statistical analysis.
http://dx.doi.org/10.1016/j.jacc.2015.04.080
759
760
JACC VOL. 66, NO. 6, 2015
Letters
AUGUST 11, 2015:754–60
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose. Jonathan Tobis, MD, served as Guest Editor for this paper.
apron less (572 h vs. 2,652 h; p < 0.001). We believe that these additional data confirm our previous assertions that time per week involved in interventional
REFERENCES 1. Orme NM, Rihal CS, Gulati R, et al. Occupational health hazards of working in the interventional laboratory: a multisite case control study of physicians and allied staff. J Am Coll Cardiol 2015;65:820–6.
procedures and use of the lead apron are associated with increased musculoskeletal pain in the catheterization lab. However, given the difference in lead apron use among physicians and technicians, additional
2. Fan G, Fu Q, Zhang H, He S. Direct-beam radiation exposure to surgeons during pinning of supracondylar humerus fractures. J Pediatr Orthop 2015; 35:e37.
factors may be involved as we described in the dis-
REPLY: Musculoskeletal Pain and Cancer Risk
parison of cancer prevalence among interventional
of Staff Working With Fluoroscopically
laboratory employees compared with noninterven-
cussion of our paper (patient transfers, sheath pull, less rotation out of the catheterization lab, and so on). Fan and colleagues also suggested that our com-
Guided Procedures
tional lab employees be stratified by working years. Our original paper reported no difference in years
We greatly appreciate the interest of Dr. Fan and
in current profession among the study or control
colleagues in our recent study published in the
group (p ¼ 0.81), which is why we did not assess as-
Journal (1). We reported that hours per week involved
sociations with cancer history stratified by working
in radiation-utilizing procedures and time per week
years. The stratified analyses suggested by Fan and
wearing the lead apron were associated with in-
colleagues also did not detect any difference in cancer
creased musculoskeletal pain. It was suggested by
prevalence between the 2 groups among employees
Dr. Fan and colleagues that we analyze these factors
working 0 to 5 years (p ¼ 0.7), 6 to 10 years (p ¼ 0.5),
using cumulative lifetime values (time per week
11 to 15 years (p ¼ 0.3), 16 to 20 years (p ¼ 0.4), or
years in profession). We did not perform the analyses
>20 years (p ¼ 0.8). The overall Cochran-Mantel-
in the original paper because of concerns on varia-
Haenszel p value was 0.78. We continue to acknowl-
tions in the weekly time spent by the operators over
edge the limitations of our cross-sectional design and
the course of their careers. However, we have per-
the need for large, longitudinal studies of employees
formed the requested analysis.
exposed to radiation.
As expected, employees participating in radiation-
vs. 2,002 h; p < 0.001) and hours wearing the lead
Nicholas M. Orme, MD Ryan J. Lennon, MS *Mandeep Singh, MD
apron (1,950 h vs. 559 h; p < 0.001). There was a
*Division of Cardiovascular Diseases
small, significant correlation between total time
Mayo Clinic
wearing the lead apron and the objective pain rating
200 First Street SW
index pain score in patients not taking pain medica-
Rochester, Minnesota 55905
tion (Spearman r ¼ 0.178; p ¼ 0.002). Nurses reported
E-mail:
[email protected] more musculoskeletal pain than physicians and
http://dx.doi.org/10.1016/j.jacc.2015.04.081
correspondingly had more lifetime hours of proce-
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose. Jonathan Tobis, MD, served as Guest Editor for this paper.
utilizing procedures who reported musculoskeletal pain had more hours of lifetime participation (6,240 h
dural participation (6,578 h vs. 2,704 h; p < 0.001) and more hours wearing the lead apron (4,940 h vs. 2,652 h; p < 0.001). Technicians also reported more pain than physicians and had higher lifetime hours of participation in radiation-intensive procedures (4,680 h vs. 2,704 h; p < 0.001) but wore the lead
REFERENCE 1. Orme NM, Rihal CS, Gulati R, et al. Occupational health hazards of working in the interventional laboratory: a multisite case control study of physicians and allied staff. J Am Coll Cardiol 2015;65:820–6.