Cardiac rehabilitation using simultaneous voice and electrocardiographic transtelephonic monitoring

may help our understanding of vascular remodeling and arterialization. Becausea growing proportion of patients presenting with acute ischemic syndromes have saphenous vein bypass grafts, the clinical implications of these findings cannot be overstated. As with coronary arteries, the degree of atherosclerotic plaque cannot be adequately assessedwith angiography. For example, compensatory enlargement may make a culprit lesion angiographically silent“ after successfulthrombolysis. In addition, segments adjacent to a stenotic lesion may not be adequate references because they underestimate vessel dimensions. Thus, sizing an interventional device to perform optimized transcatheter revascularization may be difficult without intravascular ultrasound. Furthermore, angiography may prove insensitive for a study on atherosclerotic plaque progression or regression in venous bypass grafts becauseof its inability to detect compensatory enlargement. These data demonstrate that saphenous vein grafts enlarge at sites of focal atherosclerosis and preserve luminal area for narrowing of ~30% of the cross-sectional vessel area. 1. Glagov S, Weisenerg E, Zarins CK, Stankunavicius R, Kolettis GJ. Compensatory enlargement of human atherosclerotic coronary arteries. N Engl J Med 1987:316:1371-1375.

Cardiac Rehabilitation Electrocardiographic Donald

2. Hermiller JB, Tenaglia AN, Kisslo KB, Phillips HR. Bashore TM, Stack RS, Davidson CJ. In viva validation of compensatory enlargement of atherosclerotic coronary arteries. Am J Cardiol 1993;71:665-668. 3. Losordo DW, Rosenfield K, Kaufman J, Piecmk A, lsner JM. Focal cotnpensatoty enlargement of human arteries in response to progressive atherosclerosis: in viva documentation using intravascular ultrasound. Circukzti~n 1994;89: 2570-2577. 4. Stiel GM, Stiel LSG, Schafer J, Donath K, Mathey DC. Impact of compensatory enlargement of atherosclerotic coronary arteries on angiographic assessment of coronary artery disease. Circulation 1989;80: 1603-1609. 5. McPherson DD, Sima SJ, Hiratzka LF, Thorpe L, Armstrong ML, Marcus ML, Kerber RE. Coronary arterial remodeling studied by high-frequency epicardial echocardiography: an early compensatory mechanism in patients with obstructive coronaly atherosclerosis. J Am Cull Cardiol 1991;17:7%86. 6. Beere PA, Glagov S, Zatins CK. Experimental atherosclerosis at the carotid bifurcation of the cynomologus monkey. Localization, compensatory enlargement, and the sparing effect of lowered heart rate. Arkkoscler Thrmnb 1992;12: 1245-1253. 7. Kamiya A, Togawa T. Adaptive regulation of wall shear stress to flow change in the canine carotid artery. Am J Physiol 1980;239:H14-H21. 8. Zarins CK, Zatina MA, Giddens DP, Ku DN, Glagov S. Shear stress regulation of artery lumen diameter in experimental atherogenesl5. J Vfw Surg 1987; 5:413420. 9. Langille BL, O’Donnell F. Reductions in atterial diameter produced by chronic decreases in blood flow are endothelium-dependent. Science 1986;23 1:405407. 10. Glagov S, Zarins C, Giddens DP, Ku DN. Hemodynamics and atherosclerosis: insights and perspectives gained from studies of human arteries. Arch P&al Lab Med 1988;112:1018-1031. 11. Crawford T, Levene Cl. Medial thinning in atheroma. J Pufhol 1953;66: 19-23. 12. Keren G, Douek P, Oblon C, Banner RF, Pichard AD, Leon MB. Atherosclerotic saphenous vein grafts treated with different interventional procedures assessed by intravascular ultrasound. Am Hem J 1992; 124: 198-206. 13. Spray TL, Roberts WC. Changes in saphrnous veins used as aonocoronary bypass grafts. Am Heart J 1977;94:50&5 16. 14. Isner JM, Donaldson RF, Fortin AH, Tischler A, Clarke RH. Attenuation of the media of coronary arteries in advanced atherosclerosis. Am J Cardiol 1986:58: 937-939. 15. MacIsaac AI, Thomas JD, Topel EJ. Toward the quiescent coronary plaque. J Am Coil Cardiol 1993;22:1228-1241.

Using Simultaneous Voice and l’runstelephonic Monitoring

K. Shaw, PhD, Kenneth E. Sparks, PhD, Henry S. Jennings III, MD, and Janice C. Vantrease, RN

n 1984,Fletcher,’ Miller,* and their co-workers found Itientstranstelephonic electrocardiographicmonitoring of pawith coronary artery disease who exercised at home to be both efficacious and safe. Subsequentstudies support these initial findings,3,4with the scope of investigations expanding to include compliance5 and reimbursement6issues. Research data reveal those particularly benefiting from transtelephonic exercise monitoring (TEM) are patients located in rural areas where community hospitals frequently lack resourcesto establish and maintain viable outpatient programs.7For these persons,TEM provides a workable compromisebetween exercising alone and lengthy travel to metropolitan hospital-based programs. More recently, the concept of tandem sites has developed.7Patients exercisein rural medical facilities rather than at home with TEM provided by metropolitan hospital personnel located miles away.The From the Saint Thomas Heart Institute, Saint Thomas Hospital, Nashville, Tennessee, and the Department of Ph sical Education, Cleveland State Universrty, Cleveland, Ohio. Dr. S t: aw’s address is: Cardiac Health and Rehabilitation, Saint Thomas Heart Institute, Saint Thomas Hospital, 4220 Harding Road, Nashville, Tennessee 37205. Manuscript received May 30, 1995, revrsed manuscript received and accepted August 8, 1995.

simultaneoustransmissionof voice and rhythm strip over the sametelephone line was not commercially available until 198S6Before this time, basestation operatorswere required to “toggle” between analog voice and digital electrocardiographic signals. This potentially presented an increased risk for patients and proved cumbersome to operators who received voice communication at the expense of heart rhythm and vice versa. Although the simultaneous transmission feature corrected this fault and improved product acceptance,the proliferation of this new technology has not been studied. This investigation examinesthe current statusof simultaneous voice and electrocardiographic TEM in hospital, home, and clinic settings. ... We polled all facilities (n = 32) with simultaneous voice and electrocardiographic TEM capability. Because simultaneous transmission technology is marketed by only 1 company (Scott&e Inc., Cleveland, Ohio), ScottCare’s assistancewas obtainedin providing a list of product owners, leasees,and program supervisors. Each site was then sent a packet containing a sample22-item questionnaire with accompanying letter of explanation. One month later, program supervisorswere contactedby teleBRIEF REPORTS

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phone at which time survey data were obtained. All sites participated in the study; however, 13 facilities had not yet developed formal TEM programs. Of the remaining 19 sites surveyed, 10 were currently offering the service. Survey data were obtained on 500 patients (158 women and 342 men, mean age f SD 57 + 5.7 years) with diagnosed coronary artery or pulmonary disease. All patients were referred for EM becauseof distance from metropolitan programs or becauseof convenient access to a rural tandem site. Diagnoses included coronary artery bypass surgery (n = 160), myocardial infarction (n = 140), stable angina (n = 55), percutaneoustransluminal coronary angioplasty (n = 25), orthotopic cardiac transplantation (n = 4), chronic obstructive pulmonary disease (n = 4), valve replacement (n = 3), dilated cardiomyopathy (n = 3), diabetesmellitus (n = 2), and essential hypertension (n = 1). The remaining patients had multiple cardiac diagnoses: myocardiaI infarction/coronary artery bypass surgery (n = 31), myocardial infarction/percutaneous transluminal coronary angioplasty (n = 52), and myocardial infarction/percutaneous transluminal coronary angioplasty/coronary artery bypass surgery (n = 20). The EM base station consists of a personal computer equipped with high-resolution touch screen monitor, a laser printer, headset,operating software, and proprietary electronics required for simultaneous voice and electrocardiographictranslation. Sincestandardtelephone lines are used, heart rhythms are obtained in real time with as many as 5 patients being monitored at once. The simultaneous transmission feature permits “conference call” contact facilitating patient education and group interaction. Home kits contain a telephonemodem,AC/DC power converter, head set, lead wires, and junction box. Patients receive equipment set-up and bipolar lead wire application instructions before the first exercise sessions. Home set-up is frequently available for patients who require special assistance.Some programs also provide exercise equipment on a loan or nominal cost basis. A total of 500 patients had completed 14,195exercise sessionsas of January 1995. All patients exercised at home (n = 297) or at rural tandem sites (n = 203). Aerobic-conditioning sessionslasted from 10to 45 minutes and were held 2 to 5 times each week. Target heart rates were derived from gradedexercisetest data or were set at 20 beats above rest, and progressively increased based on rating of perceived exertion values. Patients exercised on a variety of modalities including steps, treadmill, rowing machine, arm ergometer,leg ergometer, combination arm-leg ergometer, and cross-country ski ergometer.Average program length was 29 f 10 sessions (range 2 to 36). Distance from the TEM base station averaged72 f 109miles (range 1 to 600), with none of the sites reporting medical emergenciesnecessitating ambulance response. One patient was monitored from Anchorage, Alaska while exercising at home in the Aleutian Islands. A total of 243 patients (13%) discontinued the program before completion. Most of those leaving the program (75%) did so because of medical reasons or early return to work. Base station operators were most often registered nurses (n = 18) and exercise physiologists (n = 10) who had received special instruc1070

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tion in arrhythmia detection. One physical therapist and 1 monitor technician also served in this capacity. Facilities owning or leasing TEM equipment were typically metropolitan hospitals (n = 18) with an average of 495 + 166 beds. One site, a transtelephonic 12-leadelectrocardiographic service, had no hospital afliliation. A total of 141telephone disconnectsduring exercisewas reported. Most disconnects (n = 120) were traced to long distance provider difficulties (i.e., electrical storms, high winds, etc.). Average charge per sessionwas 66 dollars (range 40 to 120). Insurance reimbursement averaged 86% of the actual charge, with 24 patients denied coverage for service. Most facilities had obtained their equipment within the last 2.1 It: 1.1 years. ... Results of the present study support earlier research related to TEM efficacy, safety, compliance, and reimbursement.1-7 The development of simultaneous voice and electrocardiographictransmissionimproved the original TEM concept, which required operators to choose between voice and rhythm strip signals6 We learned that 32 facilities located in 14 statesnow have simultaneous TEM capability. Many of these programs were offering this service to rural communities in other states.The implications of this expandeduse are far-reaching because monitored cardiac rehabilitation is now available to anyone within reach of a standardtelephone. None of these TEM programs had experienced medical complications requiring ambulanceresponse.This finding is consistent with other studies1-7and appearsto be a function of several factors: (1) careful initial screening, (2) monitoring by competent personnel, and (3) judicious exercise progression. Compliance is frequently a problem for hospital-basedprograms. Approximately 25% of patients typically withdraw from supervised rehabilitation within 3 months.* This is in contrast to the presentstudy,in which the dropout rate was approximately one half this figure (13%). The fact that patients were called directly by base station operatorsgave addedincentive to not miss scheduled exercise sessions.If initial contact was not made, patients were called again immediately to rule out a possible morbid medical scenario.However, 2 patients, both of whom failed to respondwhen called, died during sleep and were found at the prompting of base station operators. Although 141telephone disconnectswere reported, they constitute
based outpatient cardiac rehabilitation programs? The exact reason for this remains unclear, but it was due in part to the billing codesused and the “newness” of TEM compared with the established outpatient program approach. It has been estimatedthat more than two thirds of the hospitals in the United Stateswith >500 beds currently offer or will soon offer outpatient cardiac rehabilitation. to However, further estimates indicate that only between 2.5% and 4% of people with active coronary artery diseaseactually enroll in cardiac rehabilitation.‘O Certainly one factor affecting enrollment is program proximity, which must be addressedif more patients are to enroll. One of the more encouraging developments toward this end is TEM; however, additional research is needed before the cost-effectivenessof these systemsis clearly elucidated. Based on the results of this survey, we conclude that simultaneous TEM technology is expanding and is an appropriate adjunct to hospital-based cardiac rehabilitation programs.

IMPLICATIONS

1. Fletcher GF, Chiaramida AJ, LeMay MR, Johnston BL, Yheil JE, Spratlin MC. Telephonically-monitored home exercise early after coro!ary artery bypass surgery. Chest 1984;86:198-202. 2. Miller NH, Haskell WL, Berra K, DeBusk RF. Home versus group exercise training for increasing functional capacity after myocardial infarction. Circulntion 1984,70:64&649. 3. DeBusk RF, Haskell WL, Miller NH, Berra K, Taylor CB. Medically directed at-home rehabilitation soon after clinically uncomplicated acute myocardial infarction: a new model for patient care. Am J Cardiol 1985;53:251-257, 4. Squires RW, Miller TD, Ham T, Micheels TA, Palma TB. Transtelephonic electrocardiographic monitoring of cardiac rehabilitation exercise sessions in coronary artery disease. Am J Cardiol 1991;67:962-964. 5. Shaw DK, Sparks KE, Hanigosky P. Exercise compliance and patient satisfaction: tramtelephonic exercise monitoring (abstr). J Cardiopulm Rehbil 1990;19:373. 6. Shaw DK. Transtelephonic exercise monitoring: medico-legal and other considerations. Exercise Standards and Malpractice Reporter 1991;5:81-86. 7. Landers CB, Allen RD. Dageforde DA, Goodin RR, Squires RW. Cardiac rehabilitation in rural Kentucky: transtelephonic ECG monitoring from a metropolitan center. J Cardiovasc Manage 1992;3:3&34. 8. Oldridge NB, Pashkow FJ. Compliance and motivation in cardiac rehabilitation. In: Pashkow FJ, DaFoe WA, eds. Clinical Cardiac Rehabilitation: A Cardiologist’s Guide. Baltimore, MD: Williams & Wilkins, 1993:338-339. 9. Meyer CC. Overview of insurance. In: Hall LK, Meyer CC, eds. Cardiac Rehabilitation: Exercise Testing and Prescription. vol. II. Champaign, IL: Human Kinetics, 1988:98-99. 10. Pasbkow FJ, Dafoe WA. Preface. In: Pashkow FJ, Dafoe WA, eds. Clinical Cardiac Rehabilitation: A Cardiologist’s Guide. Baltimore, MD: Williams & Wilkins, 1993:viii.

FOR COST-EFFECTIVENESS

The cost-effectivenessof most new technology post-datesthe technology’s introduction. Such is the case with transtelephonic exercise monitoring (TEM). Data to date indicate excellent third-party reimbursement,especially when TEM is offered in tandem with rural hospitals. Medicare coverage varies from state to state; however, home TEM is often not reimbursed while tandem-siteTEM is viewed as phaseII cardiac rehabilitation and is covered accordingly. When all insurance data from the present study were analyzed, average TEM reimbursement was 86% of the actual $66 charge. This reimbursementis slightly better than that for typical non-transtelephonic phase II cardiac rehabilitation programs (180%). Simply stated,it is systemconvenience that defines TEM’s cost-effectiveness.Patients can exercise at or near home and not have to travel great distances for monitored exercise therapy. Rural hospitals can use already existing spacein physical therapy areas; monitoring of equipment purchases and staff salary expensesis virtually eliminated. Metropolitan hospitals maintain their referral networks while providing service traditionally unavailable to rural patients. Although the future appearsbright for TEM, technology proliferation will undoubtedly be a function of reimbursement. Donald K. Shaw, PhD

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