- Email: [email protected]
No Further Question
JACC: CLINICAL ELECTROPHYSIOLOGY
VOL.
ª 2016 BY THE AMERICAN COLLEGE OF CARDIOLOGY FOUNDATION
-, NO. -, 2016
ISSN 2405-500X/$36.00
PUBLISHED BY ELSEVIER
http://dx.doi.org/10.1016/j.jacep.2016.09.010
EDITORIAL COMMENT
No Further Question Cardiac Rehabilitation Benefits Patients With Implantable-Cardioverter Defibrillators: Insurers, Are You Listening?* Rachel Lampert, MD
T
he
ability
of
implantable
cardioverter
decreases
mortality,
immediately,
exercise
can
defibrillators (ICDs) to save lives in popula-
trigger
tions at risk for sudden cardiac arrest is
“paradox,” but rather a reflection of the impact of
well-established. For the most part, quality of life
exercise on the autonomic nervous system and, in
(QOL) is preserved for ICD patients (1). However,
turn, the impact of the autonomic nervous system on
ICD shocks, described in 1 study as being punched
arrhythmia. Overall, physical fitness increases vagal
in the chest or kicked by a mule (2), decrease QOL
activity, which decreases vulnerability to ventricular
(3) and lead to psychological distress. Thus, prevent-
fibrillation. For example, experimental studies show
arrhythmias
(10).
This
is
not
really
a
ing ICD shocks is paramount in allowing ICD patients
that exercise-trained dogs are less likely to fibrillate
to enjoy a full QOL. Further, after an ICD shock, many
during myocardial infarction (11). While actually
patients curtail their activity (4), likely due to fear
exercising, however, sympathetic activity surges,
and avoidance behaviors in response to the noxious
potentially triggering arrhythmias. Thus, although
stimulus (4,5). Patients decrease activity even after
the most physically fit are overall less likely to die
implant, before receiving a shock (6). As exercise
than the sedentary, even the physically fit are more
improves QOL, this curtailment of already low
likely to die during exercise than rest (12).
activity after a shock creates a vicious cycle of inactivity and poor QOL (7,8). Intuitively,
cardiac
Based on these theoretical benefits and risks, a number of studies have evaluated whether exercise
rehabilitation,
or
exercise
training is safe for patients with ICDs, and whether it
training, should be an appropriate intervention to
is efficacious in terms of increasing fitness. In this
increase activity and thus improve QOL for ICD
months’ issue of JACC: Clinical Electrophysiology,
patients. The benefits of exercise training for patients
Pandey et al. (13) report the results of a meta-analysis
with heart failure are well-established (9). However,
of 6 studies (5 randomized controlled trials) of
although exercise training is safe in patients with
exercise-training in patients with ICDs, finding that
heart failure, the impact on ventricular arrhythmias,
exercise increases cardiorespiratory fitness (VO 2 max)
of increased importance for those with known
without increasing, and, in fact, decreasing shocks.
vulnerability to ventricular tachycardia or ventricular
The findings regarding increased fitness with super-
fibrillation such as those with ICDs, was harder to
vised exercise are not surprising and several of the
predict. The “paradox of exercise” has been well-
studies showed this alone.
described—although
in
the
long
term
exercise
The question of impact of exercise training on shocks, however, was ripe for meta-analysis, because many of the individual studies in the meta-analysis
*Editorials published in JACC: Clinical Electrophysiology reflect the views of the authors and do not necessarily represent the views of JACC: Clinical Electrophysiology or the American College of Cardiology. From the Department of Internal Medicine (Cardiovascular Medicine), Yale School of Medicine, New Haven, Connecticut. Dr. Lampert has re-
showed a tantalizing but nonsignificant trend toward improvement in shocks with exercise training. Due to the concerns detailed herein, shocks in these studies were actually a safety outcome rather than
ported that she has received research grants (>$10,000) and modest
the efficacy outcome shown here. This meta-analysis
consulting fees ($5 to $10,000) from Medtronic.
is thus the first and most definitive demonstration
2
Lampert
JACC: CLINICAL ELECTROPHYSIOLOGY VOL.
-, NO. -, 2016 - 2016:-–-
Cardiac Rehabilitation Benefits ICD Patients
that exercise training is beneficial for decreasing
et al. (17) randomized ICD patients to a home-based
arrhythmias leading to ICD shocks.
program, which included an initial cardiopulmonary
The authors note a number of important issues in
exercise test to individualize heart rate targets,
designing an exercise program for ICD patients. As
followed by 8 weeks of an aerobic training phase and
they note, a stress test before embarking on an
a 16-week maintenance phase. Those in the exercise
exercise program, to guide target heart rates as
training group showed improvement in fitness, no
increasing fitness, to ensure that heart rates with
adverse events, and a nonsignificant decrease in
exercise are below the ICD’s rate cutoffs for therapy,
shocks. Further research into home-based programs
and to identify patients who may be more prone to
is needed. This may be true particularly in the elderly,
exercise-induced arrhythmias, is imperative.
an increasing percentage of ICD recipients, for whom
It is an unfortunate aspect of the study that appropriate shocks, inappropriate shocks, and anti-
transportation to a center for cardiac rehabilitation may be even more of an issue.
tachycardia pacing–terminated ventricular tachycar-
In summary, these data now demonstrate con-
dias are rolled into a single endpoint. This is
vincingly that ICD patients benefit from exercise
unavoidable due to the heterogeneity of the end-
training in reduction of shock. Currently, many in-
points of the studies included in the meta-analysis.
surers do not reimburse exercise training after ICD
These events are different, and it would be inter-
implantation, or even after ICD shock. These data
esting to understand the impact of each. However,
clearly support the benefits of cardiac rehabilitation
because appropriate shocks, inappropriate shocks
in preventing shocks, which improves QOL in those
(14), and antitachycardia pacing–terminated ventric-
with ICDs. Cardiac rehabilitation programs should
ular arrhythmias (15) all have detrimental effects on
be reimbursed after implant to prevent ICD shocks,
mortality, this does not detract from the overall
and after an ICD shock to get patients back on
importance of the study.
their feet.
Several questions remain unanswered. First, what is the best format to deliver exercise training to pa-
REPRINT REQUESTS AND CORRESPONDENCE: Dr.
tients with ICDs? Compliance with center-based pro-
Rachel Lampert, Yale School of Medicine, 789 Howard
grams is known to be suboptimal (16). In one of the
Avenue, Dana 319, New Haven, Connecticut, 06520.
studies included in this meta-analysis, Dougherty
E-mail: [email protected].
REFERENCES 1. Leosdottir M, Sigurdsson E, Reimarsdottir G,
behaviors in ICD patients. J Cardiopulmon Rehabil
implantable cardioverter defibrillator: a meta-
et al. Health-related quality of life of patients with implantable cardioverter defibrillators compared with that of pacemaker recipients. Europace 2006;8:168–74.
Prev 2014;34:241–7.
analysis. J Am Coll Cardiol EP 2016;2:XXX–XX.
8. van Ittersum M, de Greef M, van Gelder I, Coster J, Brugemann J, van der Schans C. Fear of exercise and health-related quality of life in patients with an implantable cardioverter defibrillator. Int J Rehabil Res 2003;26:117–22.
14. Saxon LA, Hayes DL, Gilliam FR, et al. Long-term
2. Ahmad M, Bloomstein L, Roelke M, Bernstein AD, Parsonnet V. Patients’ attitudes toward implanted defibrillator shocks. Pacing Clin Electrophysiol 2000;23:934–8. 3. Irvine J, Dorian P, Baker B, et al. Quality of life in the Canadian implantable defibrillator study (CIDS). Am Heart J 2002;144:282–9.
9. Flynn KE, Pina IL, Whellan DJ, et al. Effects of exercise training on health status in patients with chronic heart failure: HF-ACTION randomized controlled trial. [Erratum appears in JAMA 2009;302:2322]. JAMA 2009;301:1451–9.
4. Sears SF, Whited A, Koehler J, Gunderson B.
10. Maron BJ. The paradox of exercise. N Engl J
Examination of the differential impacts of antitachycardia pacing vs. shock on patient activity in the EMPIRIC study. Europace 2015;17:417–23.
Med 2000;343:1409–10.
5. Lang PJ, Davis M, Ohman A. Fear and anxiety: animal models and human cognitive psychophysiology. J Affect Disord 2000;61:137–59.
11. Hull SS Jr., Vanoli E, Adamson PB, Verrier RL, Foreman RD, Schwartz PJ. Exercise training confers anticipatory protection from sudden death during acute myocardial ischemia. Circulation 1994;89:548–52.
6. Lemon J, Edelman S, Kirkness A. Avoidance behaviors in patients with implantable cardioverter defibrillators. Heart Lung 2004;33: 176–82.
12. Albert CM, Mittleman MA, Chae CU, Lee IM, Hennekens CH, Manson JE. Triggering of sudden death from cardiac causes by vigorous exertion. N Engl J Med 2000;343:1355–61.
7. Cutitta KE, Woodrow LK, Ford J, et al. Shocktivity: ability and avoidance of daily activity
13. Pandey A, Parashar A, Moore C, et al. Safety and efficacy of exercise training in patients with
outcome after ICD and CRT implant and the influence of remote device follow-up: the ALTITUDE survival study. Circulation 2010;122:2359–67. 15. Moss AJ, Schuger C, Beck CA, et al. Reduction in inappropriate therapy and mortality through ICD programming. N Engl J Med 2012;367: 2275–83. 16. Golwala H, Pandey A, Ju C, et al. Temporal trends and factors associated with cardiac rehabilitation referral among patients hospitalized with heart failure: findings from Get With The Guidelines-Heart Failure Registry. J Am Coll Cardiol 2015;66:917–26. 17. Dougherty CM, Glenny RW, Burr RL, Flo GL, Kudenchuk PJ. Prospective randomized trial of moderately strenuous aerobic exercise after an implantable cardioverter defibrillator (ICD). Circulation 2015;131:1835–42.
KEY WORDS cardiorespiratory fitness, exercise training, implantable cardioverter defibrillator, ventricular fibrillation, ventricular tachycardia
VOL.
ª 2016 BY THE AMERICAN COLLEGE OF CARDIOLOGY FOUNDATION
-, NO. -, 2016
ISSN 2405-500X/$36.00
PUBLISHED BY ELSEVIER
http://dx.doi.org/10.1016/j.jacep.2016.09.010
EDITORIAL COMMENT
No Further Question Cardiac Rehabilitation Benefits Patients With Implantable-Cardioverter Defibrillators: Insurers, Are You Listening?* Rachel Lampert, MD
T
he
ability
of
implantable
cardioverter
decreases
mortality,
immediately,
exercise
can
defibrillators (ICDs) to save lives in popula-
trigger
tions at risk for sudden cardiac arrest is
“paradox,” but rather a reflection of the impact of
well-established. For the most part, quality of life
exercise on the autonomic nervous system and, in
(QOL) is preserved for ICD patients (1). However,
turn, the impact of the autonomic nervous system on
ICD shocks, described in 1 study as being punched
arrhythmia. Overall, physical fitness increases vagal
in the chest or kicked by a mule (2), decrease QOL
activity, which decreases vulnerability to ventricular
(3) and lead to psychological distress. Thus, prevent-
fibrillation. For example, experimental studies show
arrhythmias
(10).
This
is
not
really
a
ing ICD shocks is paramount in allowing ICD patients
that exercise-trained dogs are less likely to fibrillate
to enjoy a full QOL. Further, after an ICD shock, many
during myocardial infarction (11). While actually
patients curtail their activity (4), likely due to fear
exercising, however, sympathetic activity surges,
and avoidance behaviors in response to the noxious
potentially triggering arrhythmias. Thus, although
stimulus (4,5). Patients decrease activity even after
the most physically fit are overall less likely to die
implant, before receiving a shock (6). As exercise
than the sedentary, even the physically fit are more
improves QOL, this curtailment of already low
likely to die during exercise than rest (12).
activity after a shock creates a vicious cycle of inactivity and poor QOL (7,8). Intuitively,
cardiac
Based on these theoretical benefits and risks, a number of studies have evaluated whether exercise
rehabilitation,
or
exercise
training is safe for patients with ICDs, and whether it
training, should be an appropriate intervention to
is efficacious in terms of increasing fitness. In this
increase activity and thus improve QOL for ICD
months’ issue of JACC: Clinical Electrophysiology,
patients. The benefits of exercise training for patients
Pandey et al. (13) report the results of a meta-analysis
with heart failure are well-established (9). However,
of 6 studies (5 randomized controlled trials) of
although exercise training is safe in patients with
exercise-training in patients with ICDs, finding that
heart failure, the impact on ventricular arrhythmias,
exercise increases cardiorespiratory fitness (VO 2 max)
of increased importance for those with known
without increasing, and, in fact, decreasing shocks.
vulnerability to ventricular tachycardia or ventricular
The findings regarding increased fitness with super-
fibrillation such as those with ICDs, was harder to
vised exercise are not surprising and several of the
predict. The “paradox of exercise” has been well-
studies showed this alone.
described—although
in
the
long
term
exercise
The question of impact of exercise training on shocks, however, was ripe for meta-analysis, because many of the individual studies in the meta-analysis
*Editorials published in JACC: Clinical Electrophysiology reflect the views of the authors and do not necessarily represent the views of JACC: Clinical Electrophysiology or the American College of Cardiology. From the Department of Internal Medicine (Cardiovascular Medicine), Yale School of Medicine, New Haven, Connecticut. Dr. Lampert has re-
showed a tantalizing but nonsignificant trend toward improvement in shocks with exercise training. Due to the concerns detailed herein, shocks in these studies were actually a safety outcome rather than
ported that she has received research grants (>$10,000) and modest
the efficacy outcome shown here. This meta-analysis
consulting fees ($5 to $10,000) from Medtronic.
is thus the first and most definitive demonstration
2
Lampert
JACC: CLINICAL ELECTROPHYSIOLOGY VOL.
-, NO. -, 2016 - 2016:-–-
Cardiac Rehabilitation Benefits ICD Patients
that exercise training is beneficial for decreasing
et al. (17) randomized ICD patients to a home-based
arrhythmias leading to ICD shocks.
program, which included an initial cardiopulmonary
The authors note a number of important issues in
exercise test to individualize heart rate targets,
designing an exercise program for ICD patients. As
followed by 8 weeks of an aerobic training phase and
they note, a stress test before embarking on an
a 16-week maintenance phase. Those in the exercise
exercise program, to guide target heart rates as
training group showed improvement in fitness, no
increasing fitness, to ensure that heart rates with
adverse events, and a nonsignificant decrease in
exercise are below the ICD’s rate cutoffs for therapy,
shocks. Further research into home-based programs
and to identify patients who may be more prone to
is needed. This may be true particularly in the elderly,
exercise-induced arrhythmias, is imperative.
an increasing percentage of ICD recipients, for whom
It is an unfortunate aspect of the study that appropriate shocks, inappropriate shocks, and anti-
transportation to a center for cardiac rehabilitation may be even more of an issue.
tachycardia pacing–terminated ventricular tachycar-
In summary, these data now demonstrate con-
dias are rolled into a single endpoint. This is
vincingly that ICD patients benefit from exercise
unavoidable due to the heterogeneity of the end-
training in reduction of shock. Currently, many in-
points of the studies included in the meta-analysis.
surers do not reimburse exercise training after ICD
These events are different, and it would be inter-
implantation, or even after ICD shock. These data
esting to understand the impact of each. However,
clearly support the benefits of cardiac rehabilitation
because appropriate shocks, inappropriate shocks
in preventing shocks, which improves QOL in those
(14), and antitachycardia pacing–terminated ventric-
with ICDs. Cardiac rehabilitation programs should
ular arrhythmias (15) all have detrimental effects on
be reimbursed after implant to prevent ICD shocks,
mortality, this does not detract from the overall
and after an ICD shock to get patients back on
importance of the study.
their feet.
Several questions remain unanswered. First, what is the best format to deliver exercise training to pa-
REPRINT REQUESTS AND CORRESPONDENCE: Dr.
tients with ICDs? Compliance with center-based pro-
Rachel Lampert, Yale School of Medicine, 789 Howard
grams is known to be suboptimal (16). In one of the
Avenue, Dana 319, New Haven, Connecticut, 06520.
studies included in this meta-analysis, Dougherty
E-mail: [email protected].
REFERENCES 1. Leosdottir M, Sigurdsson E, Reimarsdottir G,
behaviors in ICD patients. J Cardiopulmon Rehabil
implantable cardioverter defibrillator: a meta-
et al. Health-related quality of life of patients with implantable cardioverter defibrillators compared with that of pacemaker recipients. Europace 2006;8:168–74.
Prev 2014;34:241–7.
analysis. J Am Coll Cardiol EP 2016;2:XXX–XX.
8. van Ittersum M, de Greef M, van Gelder I, Coster J, Brugemann J, van der Schans C. Fear of exercise and health-related quality of life in patients with an implantable cardioverter defibrillator. Int J Rehabil Res 2003;26:117–22.
14. Saxon LA, Hayes DL, Gilliam FR, et al. Long-term
2. Ahmad M, Bloomstein L, Roelke M, Bernstein AD, Parsonnet V. Patients’ attitudes toward implanted defibrillator shocks. Pacing Clin Electrophysiol 2000;23:934–8. 3. Irvine J, Dorian P, Baker B, et al. Quality of life in the Canadian implantable defibrillator study (CIDS). Am Heart J 2002;144:282–9.
9. Flynn KE, Pina IL, Whellan DJ, et al. Effects of exercise training on health status in patients with chronic heart failure: HF-ACTION randomized controlled trial. [Erratum appears in JAMA 2009;302:2322]. JAMA 2009;301:1451–9.
4. Sears SF, Whited A, Koehler J, Gunderson B.
10. Maron BJ. The paradox of exercise. N Engl J
Examination of the differential impacts of antitachycardia pacing vs. shock on patient activity in the EMPIRIC study. Europace 2015;17:417–23.
Med 2000;343:1409–10.
5. Lang PJ, Davis M, Ohman A. Fear and anxiety: animal models and human cognitive psychophysiology. J Affect Disord 2000;61:137–59.
11. Hull SS Jr., Vanoli E, Adamson PB, Verrier RL, Foreman RD, Schwartz PJ. Exercise training confers anticipatory protection from sudden death during acute myocardial ischemia. Circulation 1994;89:548–52.
6. Lemon J, Edelman S, Kirkness A. Avoidance behaviors in patients with implantable cardioverter defibrillators. Heart Lung 2004;33: 176–82.
12. Albert CM, Mittleman MA, Chae CU, Lee IM, Hennekens CH, Manson JE. Triggering of sudden death from cardiac causes by vigorous exertion. N Engl J Med 2000;343:1355–61.
7. Cutitta KE, Woodrow LK, Ford J, et al. Shocktivity: ability and avoidance of daily activity
13. Pandey A, Parashar A, Moore C, et al. Safety and efficacy of exercise training in patients with
outcome after ICD and CRT implant and the influence of remote device follow-up: the ALTITUDE survival study. Circulation 2010;122:2359–67. 15. Moss AJ, Schuger C, Beck CA, et al. Reduction in inappropriate therapy and mortality through ICD programming. N Engl J Med 2012;367: 2275–83. 16. Golwala H, Pandey A, Ju C, et al. Temporal trends and factors associated with cardiac rehabilitation referral among patients hospitalized with heart failure: findings from Get With The Guidelines-Heart Failure Registry. J Am Coll Cardiol 2015;66:917–26. 17. Dougherty CM, Glenny RW, Burr RL, Flo GL, Kudenchuk PJ. Prospective randomized trial of moderately strenuous aerobic exercise after an implantable cardioverter defibrillator (ICD). Circulation 2015;131:1835–42.
KEY WORDS cardiorespiratory fitness, exercise training, implantable cardioverter defibrillator, ventricular fibrillation, ventricular tachycardia