American
Heart Journal
N o v e m b e r , 1976, Volume 92, N a m b e r 5
Editorial Rehabilitation and length of hospitalization after acute myocardial infarction Albert J. Miller, M.D. Chicago, Ill.
in 1912, Herrick wrote in his now famous article on acute coronary occlusion, 1 "the importance of absolute rest in bed for several days is clear." And subsequently, as more knowledge about the pathology of myocardial infarction was accumulated, hospitalizations of 42 days and longer became the rule. Recently it was proposed t h a t 7 days of hospitalization in "uncomplicated" acute myocardial infarction is sensible and feasible and it was recommended that a controlled clinical trial of such early hospital discharge is clinically and ethically desirable.'-' The clinician can only be confused. Certainly our guiding principle for treatment must remain the individual patient's welfare, when he is acutely ill and over the longer time, and we must not confuse this important principle with expediency of any kind. There has been considerable evidence to support the desirability of so-called "early ambulation" in the treatment of patients with acute myocardial infarction. The American Heart Association has published a booklet supporting this concept, :t and for the most part we can agree that the routine described is sensible, effective, and well tolerated. Relatively rapid institution of rehabilitation procedures in patients who have From the Cardiology Section, Department of Medicine, Northwestern University Medical School and the Department of Medicine, Northwestern Memorial Hospital, Chicago. Supported by Northwestern University Research and Education Fund Number 4253-118-05. Received for publication Dec. 17, 1975. Reprint requests to: Albert J. Miller, M.D., Northwestern Memorial Hospital, 250 East Superior St., Chicago, Ill. 60611.
November, 1976, Vol. 92, No. 5, pp. 547-548
suffered an acute myocardial infarction prevents or lessens physical deconditioning, has i m p o r t a n t psychological benefits, and does not appear to significantly alter acute mortality rate when compared to slower methods of ambulation. 3 It is likely that early ambulation decreases the frequency of thromboembolic phenomena from the legs in patients not on anticoagulant therapy. The more rapid methods of ambulation should not be confused with the chair treatment introduced by Dr. Samuel Levine. This mode of treatment, as well as use of the bedside commode and the close-by bathroom, are not intrinsically related to accelerated rehabilitation programs and have been used by "conservative" physicians for a long time. Perhaps the earlier ambulation and rehabilitation programs are more appropriately characterized by "standing warm-up exercises." In the uncomplicated myocardial infarction patient the physical routine at about 21 days (shortly before going home) would include lateral side bending with 2 pound weights, trunk twisting with 2 pound weights, touching toes from the sitting position, and walking up a flight of 10 stairs. Certainly these routines do not appear to be excessive and have much to commend them. However, they become quite cautious and timid compared to suggestions that uncomplicated myocardial infarction patients may go home after 7 hospital days. One must assume that "home" will not provide t h a t degree of rest which we define in the hospital setting, and that the oppor-
American Heart Journal
547
Miller
t u n i t y for graded rehabilitation will be sacrificed. T h e r e is no question t h a t m o s t d a n g e r o u s complications of a c u t e m y o c a r d i a l infarction occur early. P r o g r a m s of rehabilitation recognize this a n d do not p a r t i c u l a r l y address t h e m s e l v e s to the first 4 or 5 d a y s a f t e r the a c u t e insult. A c u t e m o r t a l i t y statistics are n o t influenced by rehabilitation p r o g r a m s , a n d this is not surprising. However, in the t r e a t m e n t of a c u t e m y o c a r d i a l infarction we m u s t also give a t t e n t i o n to considerations other t h a n the factor of a c u t e m o r t a l ity. During the stage of r e m o v a l of necrotic muscle fibers r e s u l t a n t f r o m a c u t e ischemia, there is d e m a r c a t i o n b e t w e e n necrotic and viable muscle cells. " I n this zone, even t h o u g h elsewhere t h e r e m a y be c o n g l o m e r a t e masses of infarcted muscle, characteristically there is a l t e r n a t i o n b e t w e e n small masses of viable muscle and areas of infarction. ' ' ' T h u s , it is characteristic with a c u t e m y o c a r d i a l infarction t h a t there is an area of ischemia of variable size, a n d there is s o m e evidence t h a t such areas of ischemia m a y persist for considerable time.:' R e m o v a l of the necrotic fibers s o m e t i m e s continues for weeks, 4 b u t scar f o r m a t i o n is seen at the beginning of the third week. U s u a l l y m o s t of the necrotic tissue is r e m o v e d by the f o u r t h week, and the scar develo p m e n t continues. In a n o t e w o r t h y editorial, B l u m g a r t and Zoll '~ e m p h a s i z e d the slow r a t e of d e v e l o p m e n t of collateral vessels after sudden c o r o n a r y occlusion. T h e s e a u t h o r s stated, " T h e slow d e v e l o p m e n t of these channels as well as of the i n f l a m m a t o r y reaction to necrosis e m p h a s i z e the i m p o r t a n c e of rest a n d reduced activity for m a n y weeks a f t e r a c u t e m y o c a r d i a l infarction, c o n t r a r y to the c u r r e n t t e n d e n c y to early a m b u lation." T h e a u t h o r a n d his co-workers 7 h a v e seen strikingly delayed healing processes in one experim e n t a l condition which m a y s o m e t i m e s be pertin e n t to healing of m y o c a r d i a l infarctions in man. E a r l y a m b u l a t i o n p r o g r a m s clearly m a k e b o t h p a t i e n t s a n d physicians feel b e t t e r sooner. B u t the l o n g - t e r m value to the p a t i e n t still m u s t be considered as u n p r o v e d in the area of our greatest concern, the effective and m a x i m a l healing of an injured muscle with the survival of as m u c h of
548
t h a t muscle as possible. After a c u t e m y o c a r d i a l infarction it is desirable to p r o t e c t the ischemic m y o c a r d i u m and to facilitate collateral vessel formation. T h e processes of healing a n d collateral vessel growth m a y be altered u n f a v o r a b l y if our concern with deconditioning becomes excessive. I t r e m a i n s to be established w h e t h e r there is a n y value to early a m b u l a t i o n of p a t i e n t s after a c u t e m y o c a r d i a l infarction other t h a n the psychologic benefit. However, there are sensible p r o g r a m s oriented to a r o u n d three weeks of hospitalization t h a t offer a reasonable middle r o u t e to follow in the light of our present knowledge, u n d e r s t a n d i n g t h a t it remains possible t h a t earlier a m b u l a t i o n is associated with m o r e f r e q u e n t late complications. Such complications would include higher r a t e s of r e c u r r e n t infarction, congestive h e a r t failure, angina pectoris, ventricular a n e u r y s m , m u r a l thrombi, a n d v e n t r i c u l a r d y s r h y t h m i a s . Such plans as those which would m a r k e d l y shorten the period of hospitalization s m a y accomplish certain cost benefits, b u t t h e y would in effect sacrifice the carefully developed p r o g r a m s of rehabilitation after acute m y o c a r d i a l infarction. One would hope t h a t e v a l u a t i o n s of the safety of m a r k e d l y a b b r e v i a t e d hospitalizations would be confined to an investigative setting in which long-term complications could be a d e q u a t e l y assessed. REFERENCES
1. Herrick, J. B.: Clinical features of sudden obstruction of the coronary arteries, J.A.M.A. 59:2015, 1912. 2. McNeer, J. F., Wallace, A. G., Wagner, G. S., Starmer, C. F., and Rosati, R. A.: The course of acute myocardial infarction: Feasibility of early discharge of the uncomplicated patient, Circulation 51:410, 1975. 3. Wenger, N. D.: Coronary care: Rehabilitation after myocardial infarction, American Heart Association, New York, 1973. 4. Lynch, R. P., and Edwards, J. E.: Pathology of coronary atherosclerosis and its complications, in Hurst, J. W., and Logue, R. B., editors, The heart, McGraw-Hill Book Co., New York, 1966, pages 658-669. 5. Pick, R., Miller, A. J., and Glick, G.: Myocardial pathology after cardiac venous and lymph flow obstruction in the dog, AM. HEARTJ. 87:627, 1974. 6. Blumgart, H. L., and Zoll, P. M.: Clinical pathologic correlations in coronary artery disease, Circulation 47:1139, 1973. 7. Kline, I. K., Miller, A. J., Pick, R., and Katz, L. N.: The effects of chronic impairment of cardiac lymph flow on myocardial reactions after coronary artery ligation in dogs, AM. HEARTJ. 68:515, 1964.
November, 1976, Vol. 92, No. 5
Heart Journal
N o v e m b e r , 1976, Volume 92, N a m b e r 5
Editorial Rehabilitation and length of hospitalization after acute myocardial infarction Albert J. Miller, M.D. Chicago, Ill.
in 1912, Herrick wrote in his now famous article on acute coronary occlusion, 1 "the importance of absolute rest in bed for several days is clear." And subsequently, as more knowledge about the pathology of myocardial infarction was accumulated, hospitalizations of 42 days and longer became the rule. Recently it was proposed t h a t 7 days of hospitalization in "uncomplicated" acute myocardial infarction is sensible and feasible and it was recommended that a controlled clinical trial of such early hospital discharge is clinically and ethically desirable.'-' The clinician can only be confused. Certainly our guiding principle for treatment must remain the individual patient's welfare, when he is acutely ill and over the longer time, and we must not confuse this important principle with expediency of any kind. There has been considerable evidence to support the desirability of so-called "early ambulation" in the treatment of patients with acute myocardial infarction. The American Heart Association has published a booklet supporting this concept, :t and for the most part we can agree that the routine described is sensible, effective, and well tolerated. Relatively rapid institution of rehabilitation procedures in patients who have From the Cardiology Section, Department of Medicine, Northwestern University Medical School and the Department of Medicine, Northwestern Memorial Hospital, Chicago. Supported by Northwestern University Research and Education Fund Number 4253-118-05. Received for publication Dec. 17, 1975. Reprint requests to: Albert J. Miller, M.D., Northwestern Memorial Hospital, 250 East Superior St., Chicago, Ill. 60611.
November, 1976, Vol. 92, No. 5, pp. 547-548
suffered an acute myocardial infarction prevents or lessens physical deconditioning, has i m p o r t a n t psychological benefits, and does not appear to significantly alter acute mortality rate when compared to slower methods of ambulation. 3 It is likely that early ambulation decreases the frequency of thromboembolic phenomena from the legs in patients not on anticoagulant therapy. The more rapid methods of ambulation should not be confused with the chair treatment introduced by Dr. Samuel Levine. This mode of treatment, as well as use of the bedside commode and the close-by bathroom, are not intrinsically related to accelerated rehabilitation programs and have been used by "conservative" physicians for a long time. Perhaps the earlier ambulation and rehabilitation programs are more appropriately characterized by "standing warm-up exercises." In the uncomplicated myocardial infarction patient the physical routine at about 21 days (shortly before going home) would include lateral side bending with 2 pound weights, trunk twisting with 2 pound weights, touching toes from the sitting position, and walking up a flight of 10 stairs. Certainly these routines do not appear to be excessive and have much to commend them. However, they become quite cautious and timid compared to suggestions that uncomplicated myocardial infarction patients may go home after 7 hospital days. One must assume that "home" will not provide t h a t degree of rest which we define in the hospital setting, and that the oppor-
American Heart Journal
547
Miller
t u n i t y for graded rehabilitation will be sacrificed. T h e r e is no question t h a t m o s t d a n g e r o u s complications of a c u t e m y o c a r d i a l infarction occur early. P r o g r a m s of rehabilitation recognize this a n d do not p a r t i c u l a r l y address t h e m s e l v e s to the first 4 or 5 d a y s a f t e r the a c u t e insult. A c u t e m o r t a l i t y statistics are n o t influenced by rehabilitation p r o g r a m s , a n d this is not surprising. However, in the t r e a t m e n t of a c u t e m y o c a r d i a l infarction we m u s t also give a t t e n t i o n to considerations other t h a n the factor of a c u t e m o r t a l ity. During the stage of r e m o v a l of necrotic muscle fibers r e s u l t a n t f r o m a c u t e ischemia, there is d e m a r c a t i o n b e t w e e n necrotic and viable muscle cells. " I n this zone, even t h o u g h elsewhere t h e r e m a y be c o n g l o m e r a t e masses of infarcted muscle, characteristically there is a l t e r n a t i o n b e t w e e n small masses of viable muscle and areas of infarction. ' ' ' T h u s , it is characteristic with a c u t e m y o c a r d i a l infarction t h a t there is an area of ischemia of variable size, a n d there is s o m e evidence t h a t such areas of ischemia m a y persist for considerable time.:' R e m o v a l of the necrotic fibers s o m e t i m e s continues for weeks, 4 b u t scar f o r m a t i o n is seen at the beginning of the third week. U s u a l l y m o s t of the necrotic tissue is r e m o v e d by the f o u r t h week, and the scar develo p m e n t continues. In a n o t e w o r t h y editorial, B l u m g a r t and Zoll '~ e m p h a s i z e d the slow r a t e of d e v e l o p m e n t of collateral vessels after sudden c o r o n a r y occlusion. T h e s e a u t h o r s stated, " T h e slow d e v e l o p m e n t of these channels as well as of the i n f l a m m a t o r y reaction to necrosis e m p h a s i z e the i m p o r t a n c e of rest a n d reduced activity for m a n y weeks a f t e r a c u t e m y o c a r d i a l infarction, c o n t r a r y to the c u r r e n t t e n d e n c y to early a m b u lation." T h e a u t h o r a n d his co-workers 7 h a v e seen strikingly delayed healing processes in one experim e n t a l condition which m a y s o m e t i m e s be pertin e n t to healing of m y o c a r d i a l infarctions in man. E a r l y a m b u l a t i o n p r o g r a m s clearly m a k e b o t h p a t i e n t s a n d physicians feel b e t t e r sooner. B u t the l o n g - t e r m value to the p a t i e n t still m u s t be considered as u n p r o v e d in the area of our greatest concern, the effective and m a x i m a l healing of an injured muscle with the survival of as m u c h of
548
t h a t muscle as possible. After a c u t e m y o c a r d i a l infarction it is desirable to p r o t e c t the ischemic m y o c a r d i u m and to facilitate collateral vessel formation. T h e processes of healing a n d collateral vessel growth m a y be altered u n f a v o r a b l y if our concern with deconditioning becomes excessive. I t r e m a i n s to be established w h e t h e r there is a n y value to early a m b u l a t i o n of p a t i e n t s after a c u t e m y o c a r d i a l infarction other t h a n the psychologic benefit. However, there are sensible p r o g r a m s oriented to a r o u n d three weeks of hospitalization t h a t offer a reasonable middle r o u t e to follow in the light of our present knowledge, u n d e r s t a n d i n g t h a t it remains possible t h a t earlier a m b u l a t i o n is associated with m o r e f r e q u e n t late complications. Such complications would include higher r a t e s of r e c u r r e n t infarction, congestive h e a r t failure, angina pectoris, ventricular a n e u r y s m , m u r a l thrombi, a n d v e n t r i c u l a r d y s r h y t h m i a s . Such plans as those which would m a r k e d l y shorten the period of hospitalization s m a y accomplish certain cost benefits, b u t t h e y would in effect sacrifice the carefully developed p r o g r a m s of rehabilitation after acute m y o c a r d i a l infarction. One would hope t h a t e v a l u a t i o n s of the safety of m a r k e d l y a b b r e v i a t e d hospitalizations would be confined to an investigative setting in which long-term complications could be a d e q u a t e l y assessed. REFERENCES
1. Herrick, J. B.: Clinical features of sudden obstruction of the coronary arteries, J.A.M.A. 59:2015, 1912. 2. McNeer, J. F., Wallace, A. G., Wagner, G. S., Starmer, C. F., and Rosati, R. A.: The course of acute myocardial infarction: Feasibility of early discharge of the uncomplicated patient, Circulation 51:410, 1975. 3. Wenger, N. D.: Coronary care: Rehabilitation after myocardial infarction, American Heart Association, New York, 1973. 4. Lynch, R. P., and Edwards, J. E.: Pathology of coronary atherosclerosis and its complications, in Hurst, J. W., and Logue, R. B., editors, The heart, McGraw-Hill Book Co., New York, 1966, pages 658-669. 5. Pick, R., Miller, A. J., and Glick, G.: Myocardial pathology after cardiac venous and lymph flow obstruction in the dog, AM. HEARTJ. 87:627, 1974. 6. Blumgart, H. L., and Zoll, P. M.: Clinical pathologic correlations in coronary artery disease, Circulation 47:1139, 1973. 7. Kline, I. K., Miller, A. J., Pick, R., and Katz, L. N.: The effects of chronic impairment of cardiac lymph flow on myocardial reactions after coronary artery ligation in dogs, AM. HEARTJ. 68:515, 1964.
November, 1976, Vol. 92, No. 5
![[Rehabilitation after acute myocardial infarction].](/assets/img/hold.png)
