CARDIOLOGY
`
`CLINICS
`
`Michael H. Crawford, MD, Consulting Editor
`
`VOLUME 7/ NUMBER 4
`NOVEMBER 1989
`
`CORONARY ANGIOPLASTY
`
`Gerald Dorros, MD, Guest Editor
`Ruben F. Lewin, MD, and
`James F. King, MD, Co-Guest Editors
`
`W. B. SAUNDERS COMPANY
`HarcOurt Brace Jovanovich, Inc.
`
`Philadelphia London Toronto
`Montreal Sydney Tokyo
`
`Page 1
`
`Medtronic Exhibit 1037
`
`Page 1
`
`Medtronic Exhibit 1037
`
`

`

`W_ B. SAUNDERS COMPANY
`Harcolm BTM‘C Jovanmich, Inc.
`Tl‘it‘ Curtis CL-nlt-r
`Inclepk'mlt'mt‘ Mature Wm
`phandr-lphia, PA 19105—3399
`
`Cardiology Clinics are also published in translated editions by the following:
`
`Spanish
`
`Nueva Editorial Inturamcricana S.A. dc C.V.
`Cedro 512, Apart-ado 26370
`06450 Mexico, Mexico
`
`Portuguese
`
`Interlivms Edicoes Ltdzi.
`Rua Commandante Coelho 1085
`CEP Z1250
`Rio (le Ianeiro
`Brazil
`
`Creek
`
`Dimitrios P. Lagos
`71 Biskini Street
`157 71, Zografou
`Athens, Greece
`
`CARDIOLOGY CLINICS
`November 1989
`Volume 7~Numbcr 4
`
`ISSN 0733—8651
`
`Copyright 15".: 198$) l}_\' W. B. Saunders Company. All rights reserved. No part of this publication may
`llt'
`reproduced til'
`iransmiltt‘d in 111W form or 11} any means. electronic or mechanical,
`including
`ljllnhmnp‘y‘ weanling.
`ial' any infin‘mulinn storage and rr-»Lriwnl system, without permission in writing
`l'run'l the publisher.
`Printed in lllt‘ Ul‘iill‘tl Slales (Ill America.
`
`Anthnrimtion to photocopy items for internal or personal mars. or the internal or personal use of
`Specific clients, is granted by W. B. Saunders Company for users I't‘gistered with the Copyright Clearance
`(Aqua, (CCU) Trausaciicmal new-”1mg Son'ice. provided thal [he bmg- fee “[50th per copy, plus 8.20
`pm [fill-[‘8‘
`i5 paid dirvull} in (jCC_ 2? Congress 5L, SalL-rn, MA [11970, For them: urgauimtiuris ihat have
`law-.1 granted a phuinctapy license by [:CC: 1 5"‘P‘1T41h‘ System Hi payment has been arranged. The PM?
`“3dr: lhr mat-rs or the Transactional liUlNJl'Ul'li-l 5‘5”“! 15?
`733-SISEUBB $00111} + 3-3”-
`
`C‘urcimiumi Clinics is pui-plished quarterly by W. B. Saunders Company, The Curtis Center,
`LI‘I‘IFP'IP'HFIII'DCL' Square Wt-si. Philadelphia. PA 19105‘3399- Subscription Pl'iC6 i5 $70-00 (U'S‘ individuals),
`:Séljlliu'l (LS, infilitntinnsl and 5.5556110 (inrcign individuals and institutions). There is a postage charge of
`ll 1.
`i For subscriptions billed in United Slates addresses and shipped outside the United States. Second,
`Efrxrpml-“fi-l‘ paid at Duluth. MN ESSUB. and .‘lcltlillonfll malhng Offices. POSTMASTER: Send addresg
`' "m“ l” W. B. Saunders Gmnpany. Customer Service, P.O. Box 6467, Duluth, MN 55806—9854.
`
`Indchlc editor of this publication is Nzu'na Cliolian. W. B Saunders Company, The Curtis Center,
`‘Ptn‘lencc Square West, Philadelphia, PA 1m.ur»3399.
`P “
`\
`llutcd b)’ the Maple—Vail Book Manufacturing Group, York, Pennsylvania.
`
`Page 2
`
`Medtronic Exhibit 1037
`
`Page 2
`
`Medtronic Exhibit 1037
`
`

`

`Coronary Angioplasty
`
`0733—8651/89 $0.00 + .20
`
`Coronary Angioplasty in Patients with
`Prior Coronary Artery Bypass Surgery:
`All Prior Coronary Artery Bypass Surgery Patients
`and Patients More than 5 Years After Coronary
`Bypass Surgery
`
`Gerald Dorms, MD,* Ruben F. Lewin, MD,T
`and Lynne M. Mathiak, RN21:
`
`MATERIALS AND METHODS
`
`Patient Selection
`
`All patients who underwent PTCA had one
`or more prior CABGs and had a significant
`coronary or vein graft stenosis(es) that produced
`severe angina or significant myocardial ische—
`mia, confirmed by noninvasive studies.
`The patient’s anatomy (that is, the site of the
`stenosis(es), determined by cineartcriograzl'ls)
`was the determinant of whether or not PTCA
`was feasible technically and his clinical condi-
`tion determined its appropriateness.
`
`Patient Evaluation
`
`Percutaneous transluminal coronary an gioe
`plasty {PTCA} has been usetl successfully in
`patients who have had prior bypass surgery
`[CABGJ as a means ofreyascularizing the myo-
`cardium and avoiding repeat myocardial res-as—
`cularization.2- 3’ 9' “45' 19' 28 Percutaneous trans-
`luminal coronary angioplasty has been effective
`for lesions in relatively new bypass grafts (3 or
`less years old), bypass grafts that are not dis-
`eased difitisely, and in patients with a relatively
`high surgical risk because ol— significant medical
`problems and/or diminished left ventricular
`function (left ventricular ejection fraction less
`than or equal to 40 per cent). Old saphcnous
`vein grafts (greater than 5 years) have been
`considered to be a relative and/or absolute
`contraindication to PTCA because of distal
`embolizationfl' 25; in the opinion of some, PTCA
`of lesions at the aortic anastomosis or within
`the graft shaft was relatively contraindicated
`because of the high restenosis rate.21* 25' 29 The
`first section in this article will detail our expe—
`rience with PTCA of prior CABC patients and
`the second section, with PTCA in the subset of
`patients 5 or more years after their last coronary
`bypass surgery.
`'
`
`the “culprit” le—
`In multiple—lesion PTCA,
`sions always were considered accessible to the
`angioplasty catheter. Selected patients under-
`went PTCA of multiple lesions, despite the
`presence of significant disease in other coronary
`vessels that would not be dilated because of the
`diseases extensive and/or diffuse nature and/or
`the small caliber of the vessel. These patients
`
`From the Department of Cardiology, St. Luke’s Medical Center, Milwaukee, Wisconsin
`
`*Interventional Cardiologist; Director, The William Dorms-Isadore Feucr Foundation for lnterventional Cardiovascular
`Disease; and Associate Clinical Professor of Medicine (Cardiology). Medical College- of Wismnsin
`Tlntm‘ventimmi Cardiologist
`i(.3;1rdiova.scular Nurse Clinician
`
`Cardiology Clinics—Vol. 7, No. 4, November 1989
`
`791
`
`Page 3
`
`Medtronic Exhibit 1037
`
`Page 3
`
`Medtronic Exhibit 1037
`
`

`

`792
`
`Gerald Dorms at (II.
`
`were considered to be capable of medical man—
`agement if the culprit lesions were dilated suc-
`cessfully.
`Selected patients preferentially underwent
`PTCA rather than repeat CABG because of an
`anticipated prohibitively high surgical morbid—
`ity and/or mortality risk (presence of multiple
`prior CABGs; functioning internal mammary
`graft(s); concomitant severe, debilitating medi-
`cal conditions; cardiogenic shock; and/or severe
`left ventricular dysfunction [left ventricular
`ejection fraction less than or equal to 35 per
`cent]).
`Patients were referred preferentially for
`PTCA when (1) there was a lack of obvious vein
`graft donor sources; (2) the significant lesion(s)
`was a vessel that had undergone coronary end—
`arterectomy(ies); (3) the patient had a previously
`complicated
`and
`prolonged
`postoperative
`course; or (4) he probably would require valve
`replacement at a future time. These high-risk
`surgical patients agreed to an attempted PTCA
`with the realization that myocardial revascular—
`ization surgery would be avoided. A few of
`these
`specific patients
`recently underwent
`PTCA while on percutaneous femorofemoral
`cardiopulmonary bypass.
`Patients were advised that complications aris—
`ing from a coronary occlusion or embolization
`of debris from a vein graft would be managed
`with the use of continuous lytic therapy” and
`would not be an indication for emergency sur-
`gery. The post—PTCA management has been
`published. ‘2
`
`Definitions
`
`Multiple—lesion PTCA was defined by the
`dilatation of two or more individual lesions in
`
`varying combinations of two or more coronary
`vessels, vein grafts,
`internal mammary grafts,
`or in diHerent segments of the same vessel.
`Multiple—lesion PTCA included the dilatation of
`tandem lesions when separated by an angio-
`graphica‘lly apparent lesion—free segment.
`A dilatation procedure was considered suc—
`cessful when (1) all
`lesions attempted were
`dilated successfully (a 20 per cent or greater
`reduction in the per cent diameter stenosis with
`less than or equal
`to 50 per cent residual
`narrowing); or (2) the culprit lesion(s) was di-
`
`lated successful; and (3) these angiographically
`successful results were accompanied by a clini-
`cal improvement within 1 week of the proce-
`dure.
`
`Clinical improvement was evaluated by the
`patient’s subjective assessment of anginal status,
`and/or by noninvasive techniques. An apparent
`symptom—related lesion recurrence was consid—
`ered present when a patient, clinically im—
`proved after PTCA, deteriorated and this wors—
`ening was
`associated with
`angiographic
`evidence of restenosis of one or more lesions.
`
`Follow-up Data
`
`Follow—up data of patients, both successful
`and unsuccessful, were obtained by periodic
`interviews (within 1 week, 3 months, 6 months,
`and yearly), via office visits, telephone calls, or
`written questionnaires that detailed the pa-
`tient’s Vital status, anginal status, occurrence of
`a myocardial infarction, repeat hospitalizations,
`and/0r subsequent PTCA or CABG. A late
`death was defined as an occurrence after hos—
`pital discharge. At a mean time of 3.3 years,
`data were obtained for 98 per cent of patients
`regarding vital status and in 92 per cent con—
`cerning anginal status.
`
`Statistical Analysis
`
`All data have been presented as the mean i
`one standard deviation. The Chi-square test
`with Yates’ correction and univariate analysis
`was utilized. A P value of less than 0.05 was
`considered statistically significant. Life-table
`analysis was performed according to published
`methods.10
`
`PERCUTANEOUS TRANSLUMINAL
`CORONARY ANCIOPLASTY IN PATIENTS
`WITH PRIOR CORONARY ARTERY
`BYPASS SURGERY
`
`Results
`
`Clinical Characteristics (Table 1)
`
`Four—hundred twenty prior CABG patients
`(mean, 83 per cent) underwent PTCA, with 85
`
`Page 4
`
`Medtronic Exhibit 1037
`
`Page 4
`
`Medtronic Exhibit 1037
`
`

`

`PTCA in Patients with Prior Coronary Artery Bypass Surgery
`
`793
`
`Table 1. Clinical Characteristics 0f420 Prior
`CABG Patients who Underwent PTCA
`420
`
`Patients
`Men
`Women
`Mean age (years)
`Prior infarction
`LVEF 535 per cent
`Angina] Class II—IV (CCSC)
`Chronic lung disease
`Prior stroke
`Chronic renal failure
`
`349 (83%)
`71 (17%)
`58.3 i 8.8
`258 (61%)
`49 (12%)
`355 (85%)
`15 (3.6%)
`15 (3.6%)
`9 (2.1%)
`
`CABG = Coronary artery bypass grafting; CCSC =
`Canadian Cardiovascular Society Class; LVEF = left ven—
`tricular ejection fraction.
`
`per cent having severe angina (Class II to IV).
`Severe left ventricular dysfunction was present
`in 12 per cent of the cases.
`
`Angioplasty Data (Table 2)
`
`Fifty per cent of patients required only one
`lesion, and 30 per cent had two lesions dilated
`to achieve the desired revascularization. A suc-
`
`cessful dilatation was achieved in 88 per cent of
`attempts—87 per cent in native arteries and 91
`per cent in vein grafts. A clinical success (pa-
`tient improvement) was obtained in 86 per cent
`of cases.
`
`Complications (Table 3)
`
`A significant complication (death, emergency
`surgery, or Q wave infarction) occurred in 21
`
`Table 2. Angioplasty Data of 420 Prior
`CABG Patients
`
`211 (50%)
`127 (30%)
`82 (20%)
`
`784 (mean, 1.9 lesions/patient)
`Lesions
`Lesions attempted per patient
`1 lesion
`2 lesions
`2 3 lesions
`Lesion success related to lesion site
`Native artery
`Vein graft
`Aortic anastomosis
`Shaft (body)
`Distal anastomosis
`Internal mammary artery
`Success
`Lesion success
`Patient success
`Patient success related to
`number of prior CABCs
`249/287 (87%)
`1 prior CABG
`88/108 (81%)
`2 prior CABCS
`18/18 (100%)
`3 prior CABCs
`24 prior CABCs
`6/7
`(86%)
`
`450/517 (87%)
`219/241 (91%)
`65/76 (86%)
`55/56 (98%)
`99/109 (91%)
`19/26 (73%)
`
`688/784 (88%)
`361/420 (86%)
`
`CABG = coronary artery bypass grafting.
`
`Table 3. Complications Encountered During PTCA
`in 420 Prior CABG Patients
`PATIENTS
`
`Complications
`Myocardial infarction
`Q Wave MI
`Non—Q Wave MI
`Coronary occlusion
`Mortality
`PTCA related
`Not PTCA related
`Emergency CABG
`Distal embolization
`Number/SVC dilated
`Number/all lesions dilated
`Summary
`Cases with no complications
`Cases with significant
`complications
`
`22 (5.2%)
`10 (2.3%)
`12 (2.9%)
`14 (3.3%)
`11 (2.6%)
`10 (2.3%)
`1 (0.3%)
`6 (1.4 %)
`16 (3.8%)
`16/241 (6.6%)
`16/784 (2.0%)
`
`347 (83%)
`21 (5.0%)
`
`M1 = myocardial infarction; CABG = coronary artery
`bypass grafting; SVG = saphenous vein graft.
`
`patients (5 per cent), with an in-hospital PTCA—
`related mortality of 2.3 per cent. Complications
`encountered were not mutually exclusive, with
`three of the six patients who died having had
`emergency surgery, and in 3 of the 12 deaths,
`an acute Q wave myocardial
`infarction was
`apparent.
`Although patients with only a native artery
`dilatation(s) were more likely to have a signifi-
`cant complication (7.7 versus 2 per cent;
`P<0.05) compared with vein graft dilatation
`patients, no specific complication (myocardial
`infarction, mortality, or emergency surgery) was
`found to be more likely to occur. Patients with
`vein graft dilatations had a low incidence of
`significant complications but an increased inci-
`dence of embolic episodes: Saphenous vein graft
`distal embolizations occurred in 16 patients (3.8
`per cent) and in 6.6 per cent of all vein graft
`lesions attempted. Nevertheless, 83 per cent of
`patients experienced no complication.
`
`Fallow—up (Table 4)
`
`During the follow—up period, an assumption
`was made so as not to underestimate the inci—
`dence of lesion recurrence: A lesion “restenosis”
`
`was responsible for (1) any cardiac-related death
`(36 patients);
`(2) all repeat CABGs, with or
`without preoperative angiography (27 patients);
`and (3) clinical deterioration requiring repeat
`PTCA (94 patients). Utilizing this assumption,
`the recurrence rate was 43 per cent (157 of 361
`patients).
`
`Page 5
`
`Medtronic Exhibit 1037
`
`Page 5
`
`Medtronic Exhibit 1037
`
`

`

`794
`
`Gerald Dorros (at al.
`
`Table 4. Follow—up of 361 Successful PTCA Prior
`CAB C Patients
`
`ALL CABC
`PATIENTS
`
`85/94 (90%)
`0.8 year
`
`71 (55%)
`31 (24%)
`
`28 (21%)
`
`99/104 (95%)
`34/37 (92%)
`36/36 (100%)
`21/23 (91%)
`8/8
`(100%)
`34/40 (85%)
`15/16 (94%)
`11/14 (79%)
`8/10 (80%)
`27 (7.5%)
`39 (11%)
`36
`21/22 (95%)
`1.1 years
`
`Repeat successful PTCA (2nd)
`Mean time lst—2nd PTCA
`Patients with angiographic
`Old (lesion recurrence)
`New (lesions not present previ-
`ously)
`Old and new
`Lesion sites
`Native artery
`Anterior descending
`Circumflex
`Right coronary
`Left main coronary
`Vein graft
`Aortic ariastomosis
`Shaft (body)
`Distal anastomosis
`Follow—up CABC
`Lute deaths
`Attributed to cardiac disease
`Repeat successful PTCA (3rd)
`Mean time 2nd—3rd PTCA (years)
`Clinical follow—up 21 year after
`PTCA (mean time, 33 years)
`(71 = 219)
`Improved anginal status
`Patients with no angina
`
`cent (Fig. 1). Univariate analysis showed that
`survival at 63 months was influenced adversely
`by gender (male, 87 i 3 per cent versus female,
`95 i- 3 per cent; P<0.01; Fig. 2) and ventricular
`ejection fraction (less than or equal to 35 per
`cent, 77 i 8 per cent versus greater than 35
`per cent, 91 i- 2 per cent; P<0.001; Fig. 3).
`Age did not affect survival initially (greater than
`or equal to 70 years, 89 i 2 per cent versus
`less than 70 years, 92 i 5 per cent; P=NS;
`Fig. 4).
`When death or post—PTCA repeat CABG was
`used as the cardiac event marker, the probabil-
`ity was 77 i 5 per cent that a patient would
`be alive and would not have undergone repeat
`CABC (see Fig. 1) at 87 months. In addition,
`the cardiac event—free (death, CABC, and/0r
`myocardial infarction) probability was 72 i 5
`per cent at 87 months (see Fig. 1).
`
`183/219 (84%)
`117/219 (53%)
`
`DISCUSSION
`
`CABC = coronary artery bypass grafting; PTCA =
`percutaneous transluminal coronary angioplasty.
`
`A successful second PTCA was performed in
`85 of 94 restenosed patients (90 per cent) at a
`mean time of 9 months after the first PTCA.
`
`Coronary arteriography showed that 74 per cent
`had had a restenosis of the previously dilated
`lesion, with or without disease progression, and
`26 per cent had had only a new lesi0n(s) (disease
`progression). Without
`those 20 patients with
`disease progression,
`the presumptive recur-
`rence rate would be 38 per cent (137 of 361
`patients).
`There were 219 patients alive 12 or more
`months after their PTCA procedure (mean time,
`3.3 years). Clinical data indicated that 84 per
`cent of patients had an improved angina] status,
`and 53 per cent had no angina.
`A second clinical recurrence occurred in 22
`
`of 85 patients (26 per cent), with a third PTCA
`(mean time, 12 months) performed successfully
`in 21 patients (95 per cent).
`
`Life-table Analysis
`
`The cumulative probability of survival for the
`entire group, at 87 months, was 86 i 3 per
`
`Percutaneous transluminal coronary angio-
`plasty and CABG are effective revascularization
`techniques for symptomatic patients with ob-
`structive coronary artery disease. Neither tech—
`nique cures atherosclerosis. The disease process
`continues as long as the patient remains alive
`and,
`in time, will affect
`the arteries or vein
`grafts,
`the latter often virulentlyfi6'18”"32 A
`second operation (CABC) has been estimated
`to be performed in 1.1 per cent of prior CABC
`patients per year for the first 5 years, and in
`3.9 per cent per year thereafter. Although a
`cumulative percentage of reoperation has been
`reported to be 19 per cent at 12 years,23 other
`studiesEa have shown that reintervention has
`
`been necessary because of symptom recurrence
`in 12 per cent of patients after
`their
`first
`CABC—a repeat CABG in 8.3 per cent,
`a
`PTCA in 2.3 per cent, and both in 1.2 per cent.
`Repeat surgical revascularization usually was
`done because of vein graft closure; when occur—
`ring early in the postoperative course,
`it was
`considered secondary to surgical
`technique,
`and, when late, because of atherosclerotic dis-
`ease within the graft conduit or in the vessel
`distal to the anastomotic site.
`
`Page 6
`
`Medtronic Exhibit 1037
`
`Page 6
`
`Medtronic Exhibit 1037
`
`

`

`PTCA in Patients with Prior Coronary Artery Bypass Surgery
`
`795
`
`1.00
`
`
`
`CUMULATIVEPROBABILITYOFSURVIVAL
`
`is c:
`
`in o
`
`\J o
`
`0 Death
`
`Death + CABG
`
`l Death + CABG + MI
`
`2:: o
`
`1
`
`6
`
`12
`
`18
`
`24
`
`
`30
`36
`42
`48
`54
`60
`66
`72
`78
`84
`
`MONTHS
`Figure l. Liter-able analysis of patients with prior CABG after successful PTCA for cardiac-related events; lower numbers
`represent lhu patients at risk for (lentil, death and rcpt-at myocardial rm'nscularization (CABG), and both plus myocardial
`infarction {MI-l.
`
`Repeat Coronary Artery Bypass Crafting
`(Table 5)
`
`Patients who underwent repeat CABG were
`younger and had better ventricular function
`
`than the original bypass surgery patient to
`hurt. "J' 5' In surgical series published since 1950,
`the mean time from the first
`to the second
`CABG has ranged between 36 and 98 months,
`with mortality/16‘ 17‘ 2” and morlJitiily (Table 6)
`
`Male ~ Female
`
`.90
`
`.80
`
`JO
`
`_60
`
`.50
`
`
`
`CUMULATIVEPROBABILITYOFSURVIVAL
`
`
`
`0
`
`Female
`
`I Male
`
`p = 0.01
`
`48
`55
`276 233
`
`20
`26
`28
`36
`41
`46
`77
`114
`125
`159
`170
`225
`
`
`12
`18
`24
`30
`36
`42
`48
`54
`60
`MONTHS
`Figure 2. Life-table analysis for patients with prior CABG after successful PTCA showing a statistically significant
`increased prolmlaility of sun-ix n1 for women.
`
`1
`
`6
`
`Page 7
`
`Medtronic Exhibit 1037
`
`Page 7
`
`Medtronic Exhibit 1037
`
`

`

`796
`
`Gerald Dorms at al.
`
`_L O O
`
`in o
`
`'oo o
`
`a, O
`
`6') o
`
`in o
`
`N
`
`o
`
`I
`
`> 35% LVEF
`
`: 35% LVEF
`
`p 5 0.001
`
`
`
` 85 CUMULATIVEPROBABILITY0FSURVIVAL
`
`275
`
`247
`
`56
`
`34
`
`241
`
`30
`
`192
`
`19
`
`179
`
`16
`
`142
`
`11
`
`132
`
`8
`
`91
`
`6
`
`4
`
`1
`
`6
`
`12
`
`18
`
`24
`
`30
`
`36
`
`42
`
`48
`
`MONTHS
`Figure 3. Lifeetable analysis for patients with prior CABG after successful PTCA showing a statistically significant
`probability of survival for patients with left ventricular ejection fraction (LVEF) greater than 35 per cent.
`
`increased significantly as compared with that at
`the initial procedure. Variables aiTecting sur-
`vival adversely after repeat CABG included
`advanced age, left ventricular dysfunction, and
`
`diffuse coronary disease} 15’ 17' 24 A recurrence
`of angina after a repeat CABG has occurred at
`a yearly rate of 3.5 to 7.2 per cent.” 31 Repeat
`CABG has been veiy effective in selected pa—
`
`1.00
`
`.90
`
`.80
`
`-7°
`
`’60
`
`.50
`
`0
`
`I
`
`< 70 Years
`
`z 70 Years
`
`p 2 NS
`
`
`
`CUMULATIVEPROBABILITYOFSURVIVAL
`
`298
`33
`
`256
`25
`
`247
`24
`
`196
`15
`
`180
`15
`
`142
`11
`
`130
`10
`
`91
`6
`
`84
`5
`
`1
`
`6
`
`12
`
`18
`
`24
`MONTHS
`Figure 4. Life-table analysis of patients with prior CABG after successful PTCA showing no change in survival when
`stratified by age (less than 70 versus more than 70 years old)
`
`30
`
`36
`
`42
`
`48
`
`Page 8
`
`Medtronic Exhibit 1037
`
`Page 8
`
`Medtronic Exhibit 1037
`
`

`

`PTCA in Patients with Prior Coronary Artery Bypass Surgery
`
`797
`
`PATIENTS
`
`PER CENT‘
`
`Table 5. Published Results Regarding Mortality and Survival of Patients who have
`Undergone Repeat Bypass Surgery
`OPERATIVE MORTALITY
`(PER CENT)
`— PER CENT
`TIME
`lst
`2nd
`CPS
`
`39
`3.1
`5.3
`—
`3
`283
`Foster (CASS)
`36
`—
`4
`4.6
`112
`LamaslE
`6.2
`106
`SChafF2
`—
`—
`2.8
`—
`58
`Hall17
`—
`2.8
`9.2
`8. 6
`64
`CameronS
`98
`—
`——
`8.6
`89
`Keoni“
`54
`1.2
`5.6
`—
`625
`Loopis
`91
`—
`3.2
`—
`—
`8
`10
`636
`Dorrosll
`—
`—
`5.8
`8
`514
`Normal LV function
`
`—— 17.1
`
`LV dysfunction
`111
`2
`
`94 (5)—'ears)
`75 (5 years)
`82(10 years)
`879( vears)
`82 (5 years)
`
`*Per cent of original cohort of lst coronary artery bypass graft (CABG); Time = time from lst to 2nd CABG in months;
`CPS = cumulative probability of survival; CASS = Coronary Artery Surgical Study; lst and 2nd refer to the lst and 2nd
`coronary bypass surgery; (—) = not reported; LV = left ventricle.
`
`tient groups. Angioplasty can be equally effica—
`cious in appropriately selected patients, how-
`ever, and can obtain clinical success while being
`less invasive and having a lower morbidity and
`mortality. The relief of angina and long—term
`survival was comparable with PTCA and CABG.
`
`avoided as being unfeasible technically because
`of (l) the difficulty of opening the chest rapidly;
`(2) finding the appropriate vessels; and (3) re—
`establishing blood flow to the compromised
`vessels in a reasonable time frame,
`thereby
`preventing a myocardial infarction.
`
`Angioplasty in Prior Bypass Patients (Table 7)
`
`Angioplasty in Vein Grafts (see Table 6)
`
`The 88 per cent angiographic success rate,
`reported herein, resulted in a Clinical improve-
`ment in 86 per cent of the patients. The major
`complications encountered in our series were
`not
`increased significantly as compared with
`those studies with predominantly single—vessel
`coronary disease patients who did not have the
`high proportion of multivessel coronary artery
`disease (89 per cent), patients with left ventric—
`ular dysfunction (12 per cent), and geriatric
`patients (15 per cent). The incidence of emer-
`gency CABG was low (1.4 per cent) and,
`in
`part, was planned. Emergency surgery was
`
`The complications associated with PTCA in
`prior CABG patients were of concern, espe—
`cially with regard to their management. The
`complications encountered, although not neg-
`ligible, however, were comparable to those
`occurring with the repeat surgical alternatives.
`Angioplasty of vein graft lesions had a better
`success rate and lower incidence of complica—
`tions than PTCA attempted on native artery
`lesions. The vein graft restenosis rate, however,
`was significantly higher than that
`in native
`arteries. In this series, the restenosis rate varied
`between 24 per cent (the distal anastomosis)
`
`Table 6. Complications Reported with Repeat Coronary Bypass Surgery
`STEKNAL
`WOUND
`RESPIRATORY
`MORTALITY'
`PERIOP MI
`CVA
`COMPLICATIONS
`INFECTION
`(PER CENT)
`(FER CENT)
`(PER CENT)
`(PER CENT)
`(PER CENT)
`
`8.0
`2.6
`5.4
`1.4
`3.2
`625
`Loop”
`14
`H
`—
`3
`2.8
`112
`Allen‘
`7.5
`0.9
`0.9
`1.9
`2.8
`106
`Schaflnl
`
`
`
`
`283 5.3 6 0 3Foster (CASS) 1
`
`
`
`PATIENTS
`
`*Opcrative mortality.
`Perinp = periopeml'ire; MI 2
`Coronary Artery Surgical Study.
`
`myocardial infarction; CVA = cerebrovasclar accident; (—)
`
`not reported; CASS =
`
`Page 9
`
`Medtronic Exhibit 1037
`
`Page 9
`
`Medtronic Exhibit 1037
`
`

`

`798
`
`Gerald Dorms et al.
`
`420
`
`241/517
`
`88/86
`
`2.3
`
`1.4
`
`
`Table 7. Results of PTCA in Prior Bypass Surgical Patients That Have Been Published Since 1985
`SUCCESS:
`ANGIO/
`CLINICAL
`COMPLICATIONS:
`PATIENTS
`VG/NA
`(PER CENT)
`DEATH/CABG/MI (PER CENT)
`
`COtCn
`82
`83/—
`85/70
`0
`1.2
`E mst15
`83
`33/59
`91/86
`0
`0
`Reeder50
`19
`19/—
`84/84
`5
`0
`Douglas13
`166
`166/7
`7/7
`—
`—
`CorbelliS
`94
`62/47
`90/88
`1
`4
`Platlx'own
`101
`107/—
`92/—
`2
`—
`Dorms”
`76
`53/81
`85/86
`3
`1
`Dorms
`(present study)
`
`ANGINA
`NOILESS
`(PER CENT)
`
`71/7
`46/fi
`7/78
`7/92
`— /63
`T /53
`46/60
`
`53/84
`
`3.6
`2. 4
`5
`7
`2
`6
`1
`
`2.3
`
`VC 2 vein graft; NA = native artery; VC/NA = lesions attempted in vein graft and native arteiy; angio : angiographic;
`clinical refers to clinical improvement; CABG : coronary artery bypass grafting; Ml : myocardial infarction; angina, less
`is in comparison with status prior to lst PTCA; (-) 2 not reported.
`
`and 50 per cent (the aortic anastomosis). Sur—
`prisingly, patients in whom a vein graft dilata—'
`tion was done were more likely to have an
`uneventful and successful procedure than when
`a native artery lesion was related. The reason
`for this difference cannot be determined from
`
`the data, but could be related to the fact that
`when only a native artery was dilated to achieve
`revascularization,
`then (1) the myocardial re-
`serve had been severely compromised because
`of vein graft closure; (2) the vessel dilated had
`been bypassed previously and was more prone
`to dissection; (3) if a vessel closed, emergency
`surgery was not to be performed; and (4) PTCA
`was being attempted in patients with more
`diffuse disease. Although the incidence of distal
`embolization after vein graft dilatation was of
`considerable concern,
`the sequelae of such
`events appeared not
`to have the predicted
`disastrous consequences.“ 25 Distal emboliza—
`tion was managed successfully utilizing re—
`peated balloon inflations; which fractionated the
`debris, and often was done in combination with
`continuous lytic therapy (urokinase, 2000 U per
`minute for 24 to 48 hours).
`
`Follow-up
`
`Follow-up data of successful PTCA in prior
`CABG patients showed that (1) repeat PTCA
`was performed successfully (90 per cent) in 26
`per cent of patients; and (2) the lesion recur-
`rence rate approached 43 per cent, if all patients
`who died of cardiac causes and those who
`
`the repeat PTCA patients (9 months after the
`first PTCA) showed that 25 per cent of patients
`had new lesions without any recurrence of
`previously dilated lesions. Clinical deterioration
`did not always represent failure of the PTCA
`but, rather, might have indicated progression
`of disease.
`
`The clinical results during follow up appeared
`satisfactory, with anginal relief being 84 per
`cent and abolition of angina having been
`achieved in 53 per cent of the patients. These
`results were comparable to those in patients
`after repeat CABG, with only 47 per cent
`having significant angina] relief 5.5 years after
`surgery.25
`The data reported herein have shown that
`PTCA in prior CABG patients: (1) accomplished
`an angiographically successful dilatation with
`equal facility in vein grafts (91 per cent) and
`native arteries (84 per cent); (2) the site of vein
`graft dilatation (proximal or distal anastomosis,
`or body shaft) did not change the success rate;
`and (3)
`the dilatation of the culprit
`lesi0n(s)
`achieved an immediate clinical improvement in
`86 per cent of patients.
`
`PERCUTANEOUS TRANSLUMINAL
`CORONARY ANGIOPLASTY IN PATIENTS
`5 YEARS OR MORE AFTER CORONARY
`BYPASS SURGERY
`
`The age of a saphenous vein graft, in and of
`itself, has been considered a relative contrain-
`dication to the use of PTCA. This assessment
`
`underwent repeat CABG and/or PTCA were
`included. In fact, the coronary arteriograms in
`
`was based on the pathologic evaluation (gross
`and histologic) of surgically removed vein grafts
`
`Page 10
`
`Medtronic Exhibit 1037
`
`Page 10
`
`Medtronic Exhibit 1037
`
`

`

`PTCA in Patients with Prior Coronary Artery Bypass Surgery
`
`799
`
`Table 9. Angioplasty Data in Patients 5 Years or
`More Remote from Their Last Coronary Bypass
`
`Surgery
`ALL PATIENTS
`
`Lesions attempted
`457
`Mean number/patient
`1.8
`Lesions attempted/patient
`1 Lesion
`2 Lesions
`2 3 Lesions
`Success according to
`site dilated
`Native artery
`Saphenous vein graft
`Aortic anastomosis
`Shaft (body)
`Distal anastomosis
`Internal mammary artery
`Successes
`406/457 (89%)
`Success/lesions
`
`Success/patients 216/258 (84%)
`Success/lesions refers to angiographic success; success/
`patients refers to clinical improvement.
`
`260/304 (86%)
`129/144 (90%)
`42/50 (84%)
`39/40 (98%)
`48/54 (89%)
`(78%)
`
`7/9
`
`133 (52%)
`81 (31%)
`44 (17%)
`
`Complications (Table 10)
`
`No complication occurred in 81 per cent of
`cases. A significant complication (death, emer—
`gency surgery, or Q wave myocardial infarction)
`occurred in 15 patients (5.8 per cent). The in-
`hospital mortality related to PTCA was 2.3 per
`cent. Five of the six patients whose death was
`
`Table 10. Complications of PTCA in Patients 5
`Years or More Remote from Their Last Coronary
`Bypass Surgery
` PATIENTS
`Complications
`Myocardial infarction
`Q Wave MI
`Non—Q Wave MI
`Coronary spasm
`Coronary occlusion
`Mortality
`Related to PTCA
`Not related to PTCA
`Emergency CABC
`Embolization
`Number/only SVG dilated
`Number/all lesions dilated
`Cases with:
`No complications
`210 (81%)
`
`Significant complications 15 (5.8%)t
`
`9 (3.5%)
`11 (4.3%)
`
`6 (2.3%)
`1 (0.4%)
`
`13/144 (9.0%)*
`13/457 (2.8%)t
`
`20 (7.8%)
`
`4 (1.6%)
`7 (2. 7%)
`7 (2.7%)
`
`3 (1.2%)
`13 (5.0%)
`
`and on the surgical experience that excessive
`manipulation of old vein grafts could produce
`distal embolization.“' 11' 13' ‘9' 21
`
`section details our experience with
`This
`PTCA in patients who are 5 years or more
`remote from their last CABC who had dilation
`
`of a native arterial lesion(s) and/or a vein graft
`lesi0n(s). A comparison often will be made
`between those patients who had only a native
`arterial lcsion(s) dilated and those who had a
`vein graft
`lesion(s) dilated with or without a
`concomitant dilatation of a native artery le-
`sion(s).
`
`Results
`
`Clinical Characteristics (Table 8)
`
`The clinical characteristics of 258 patients
`who underwent PTCA 5 years or more after
`CABG showed that the predominant presenting
`symptom in 86 per cent of patients was severe
`angina (Class II to IV). A comparison of patients
`in whom PTCA was performed on saphenous
`vein graft and those in whom only native artery
`PTCA was performed showed no statistical dif—
`ference in their clinical characteristics.
`
`Angioplasty Data (Table 9)
`
`The results of the angioplasty procedure
`showed no statistical difference in angiographic
`success, whether a native artery or saphcnous
`vein graft
`lesion was dilated. Success was
`achieved in 89 per cent of lesions attempted
`(90 per cent of vein graft and 86 per cent of
`native artery lesions) and produced a clinical
`improvement in 84 per cent of patients.
`
`Table 8. Clinical Characteristics of Patients who
`had PTCA 5 Years or More After Coronary Bypass
`Graft Surgery
`ALL PATIENTS
`
`258
`
`Patient data
`Men
`Women
`Mean age (years)
`Prior myocardial infarction
`Left ventricular ejection
`fraction $35 per cent
`222 (86%)
`Angina] Class II—IV (CCSC)
`
`Lytic therapy utilization 13 (5.0%)
`CCSC = Canadian Cardiovascular Society Class;
`lytic
`therapy = urokinase or streptokinase.
`
`221 (86%)
`37 (14%)
`58.7 i 9
`161 (62%)
`32 (12%)
`
`MI : myocardial infarction; Q wave MI = transmural
`infarction; non—Q wave M1 = subendocardial MI; PTCA =
`percutaneous transluminal coronary angioplasty; CABC =
`coronary artery bypass grafting; SVG = saphenous vein
`graft.
`*Number of embolic episodes per suphenous vein lesions
`dilated.
`TNumber of embolic episodes per all lesions dilated.
`iEmergency CABC, myocardial infarction, and death.
`
`Page 11
`
`Medtronic Exhibit 1037
`
`Page 11
`
`Medtronic Exhibit 1037
`
`

`

`800
`
`Gerald Dorros et al.
`
`PTCA—related had a coronary occlusion—four
`patients abruptly closed the dilated native ves-
`sel within 30 minutes following PTCA and the
`fifth had an abrupt closure 6 hours post—proce»
`dure. The sixth patient died after balloon infla~
`tion of electromechanical dissociation.
`
`Although the saphenous vein graft patients
`were more likely to have a significant compli-
`cation than the native artery-only patients (8.5
`versus 2.6 per cent; P<0.05), no specific com-
`plication statistically was more likely to occur.
`Saphenous vein graft patients had fewer signif-
`icant complications but had an increased inci-
`dence of vein graft embolic episodes over native
`artery-only patients (9.5 versus 1.4 per cent;
`P<0.05). These embolic episodes were associ—
`ated with a significant increase in non—Q wave
`infarctions (6 versus 2.8 per cent; P<0.05).
`
`Follow-up (Table 11)
`
`the same as-
`During the follow-up period,
`sumption as described in the first section was
`made so as not to underestimate the incidence
`of lesion recurrence: A lesion “restenosis” was
`
`considered responsible for any cardiac-related
`death (21 patients), all repeat CABCs (23 pa-
`tients), and/or repeat PTCA (58 patients). The
`
`resulting presumptive recurrence rate was 47
`per cent (102 of 216). If the nine patients who
`underwent PTCA for new disease only were
`excluded, then the presumptive recurrence rate
`would be 43 per cent. A successful second
`PTCA was performed in 52 of 58 patients (90
`per cent). Coronary arteriography in the pa-
`tients undergoing repeat PTCA showed that 47
`per ce