Elective stenting of carotid artery stenosis in patients with severe coronary artery disease

Transcription

1 European Heart Journal (1998) 19, Article No. hj Elective stenting of carotid artery stenosis in patients with severe coronary artery disease J. Waigand, C. M. Gross, F. Uhlich, J. Krämer, C. Tamaschke*, P. Vogel, F. C. Luft and R. Dietz Franz Volhard Clinic at the Max Delbrück Center, Virchow Clinic, Humboldt University of Berlin, Berlin, *Department of Vascular Surgery, Department of Neurology, Klinikum Berlin-Buch, Berlin, Germany Aims To evaluate the feasibility and safety of elective carotid stent implantation in patients with carotid stenoses and concomitant coronary artery disease, as an alternative to combined carotid and coronary surgery. Methods We treated 50 patients with >70% stenoses in 53 carotid arteries with balloon angioplasty followed by elective stent implantation. All patients had severe coronary artery disease, and/or mitral insufficiency, aortic stenosis, rhythm disorders or generalized arteriosclerosis. In three patients the opposite carotid artery was occluded; nine patients had bilateral stenoses of which two received stents bilaterally. Results Fifty-six successful stent implantations (42 Wallstents, eight BeStents, two AVE-Microstents, one Palmaz Schatz stent, three Sito stents) were performed, reducing the baseline percent stenosis from 78 18% to 13 11%. Complications included three transient ischaemic attacks, one minor and one major stroke. Follow-up was available for 46 patients over a mean of 10 months. Three asymptomatic restenoses and one deformation of a BeStent occurred. Conclusion Our preliminary results indicate that carotid artery stenting in patients with concomitant severe coronary artery disease is feasible, safe, and may be an alternative to combined carotid and coronary surgery. (Eur Heart J 1998; 19: ) Key Words: Carotid stenosis, coronary artery disease, coronary artery bypass graft, carotid stents. See page 1278 for the Editorial comment on this article Introduction Revision submitted 9 March 1998, and accepted 12 March Correspondence: Jürgen Waigand, M.D. Franz Volhard Clinic, Wiltberg Strasse 50, Berlin, Germany X/98/ $18.00/0 Certain forms of coronary artery disease, such as left main stem stenosis and three-vessel disease in the face of poor ventricular function, are better treated operatively than with percutaneous techniques [1]. However, severe coronary artery disease and severe arteriosclerotic disease elsewhere commonly coincide [2]. Cardiac surgeons are reluctant to perform coronary artery bypass grafting in patients who also have tight carotid artery stenoses, even when these stenoses are asymptomatic. The argument raised is that hypotension, a not uncommon occurrence in the patient with poor ventricular function, could result in an intra-operative stroke. Similarly, vascular surgeons are reluctant to perform carotid endarterectomy on patients with severe coronary artery disease and/or poorly functioning left ventricles, because of a possible intra-operative or peri-operative myocardial infarction. Finally, neurologists are divided in their opinions on treating asymptomatic albeit significant carotid artery stenoses, particularly in patients with other severe or even life-threatening clinical problems elsewhere. The current evidence suggests that asymptomatic carotid disease is not a contraindication to coronary artery bypass grafting [3 5], although Brener et al. [3] observed that the operative mortality rate after cardiac surgery was three times higher in patients with carotid disease than in those patients with normal carotid arteries. A combined operation, addressing both carotid and coronary disease, is a more risky alternative than either operative procedure alone [6,7]. The potential medical legal ramification of this clinical dilemma, particularly for the cardiologist responsible for such patients with multiple problems, is still not clear. We therefore began an observational study to determine the feasibility of percutaneously treating carotid artery stenoses in such high risk patients with combined carotid and coronary disease who clearly needed coronary artery bypass grafting or percutaneous coronary angioplasty The European Society of Cardiology

2 1366 J. Waigand et al. Methods We offered extracranial carotid artery stenting to patients with symptomatic or asymptomatic carotid disease and severe coronary artery disease, who needed coronary artery bypass grafting. We also suggested this treatment to patients who were advised to undergo high risk percutaneous coronary angioplasty, and to a small number of patients with generalized arteriosclerosis, left ventricular dysfunction after coronary artery bypass grafting, valvular or rhythm disorder. After consulting our ethical committee, we modified our written consent procedure to inform the patient more precisely about the reasons for our recommendation and the risk of possible stroke. All patients underwent a physical examination, including detailed neurological examination by a consulting neurologist. The patients offered carotid stenting were found to have significant (>70% stenosis) carotid artery disease in addition to their coronary disease. Their condition was revealed first with non-invasive colour duplex scanning and then by carotid angiography with quantitative assessment (Siemens AG, Erlangen, Germany). The carotid angiograms were reviewed by a radiologist and by a vascular surgeon, who determined the severity of each lesion according to the criteria of the North American Symptomatic Carotid Endarterectomy Trial [8]. Patients with severe carotid disease all underwent cranial computerized tomography. The indication for carotid stent implantation was determined by a cardiac surgeon, a vascular surgeon, and the attending cardiologist, who reviewed all of the findings. The patients were re-examined by colour duplex scanning at 48 h, 4 weeks, and 6 months after intervention and scheduled for repeat angiography. All patients received aspirin 100 mg once a day. Low molecular weight heparin was given after stent placement and was discontinued at the time of discharge. Ticlopidine 250 mg twice daily was administered 2 days before the intervention and was continued for 4 weeks. In patients subsequently undergoing coronary artery bypass grafting, aspirin and ticlopidine were discontinued 2 to 7 days prior to operation and were replaced by low molecular weight heparin. The mean length of elapsed time between carotid stent implantation and percutaneous coronary angioplasty was days; for surgical revascularization and/or valve replacement days. Vascular access was gained by placement of a 7 or 8 F sheath into the femoral artery and a 6 F sheath into the femoral vein. A transvenous pacemaker was placed in the right ventricle in all patients. Heparin was administered by intra-arterial bolus ( IU) before starting selective angiography of the diseased carotid artery with a 7 or 8 F percutaneous coronary angioplasty guiding catheter (Judkins right or Amplatz right, Tourguide, Guidant Inc., Temecula, U.S.A.). On-line, quantitative angiography was performed to measure the severity of the stenotic lesion as well as the pre- and post-stenotic diameter of the internal carotid artery. This precise measurement was conducted so that the balloon and stent diameter selected would correspond with the size of the ipsilateral non-diseased region of the vessel. After crossing the lesion with a coronary flexible hydrophilic coated guide with (0 014 Hanibal, Schneider Inc., Bülach, Switzerland), pre-dilatation with a 4 0 mm coronary perfusion balloon catheter was performed. In most cases, we used the coronary Wallstent with a 6 mm diameter (Schneider Inc., Bülach, Switzerland), while the peripheral Wallstent (8 to 10 mm in diameter) was implanted in ostial or bifurcational stenoses. In the minority of our patients we used the BeStent (Medtronic Inc., Minneapolis, MN, U.S.A.), the AVE-Microstent (AVE Inc., Richmond, Canada), the Palmaz-Schatz stent (Johnson & Johnson Inc., Warren, NJ, U.S.A.), and the Sito stent (Jomed Inc., Rangendingen, Germany), followed by routine high pressure dilatation (14 16 atm) with a 5 0 to 6 0 mm coronary dilatation catheter (Bypass speedy, Schneider Inc., Bülach, Switzerland). After the procedure, angiography and quantitative measurement of the carotid vessel were again performed, before removing the vascular sheaths. Clinical, duplex scanning, angiographical, and neurological data were prospectively recorded. The primary end-points were neurological and cardiac complications, namely transient ischaemic attack, minor or major stroke, myocardial infarction (new Q wave or twofold elevation of creatine kinase), or death. Restenosis rate was defined as lumen narrowing 50% angiographically or an increase of the ratio in peak systolic velocity of the internal carotid artery to the end-diastolic velocity of the common carotid artery 10 at follow-up. All values are expressed as mean SD and a value of P 0 05 was considered statistically significant. Results We treated 42 men and eight women ranging in age from 46 to 89 years (Table 1). Twenty-three patients had previous myocardial infarctions; four out of these had undergone coronary bypass graft surgery because of diminished left ventricular function. Thirty-one had severe two or three coronary vessel disease and six had one vessel disease. Nineteen patients were diabetic and 23 were smokers. In 24 patients, coronary artery bypass surgery was advised, in 23 patients we performed high risk percutaneous coronary angioplasty. Three patients had mitral insufficiency without, and three had aortic stenosis with the need for valve replacement. Fourteen patients had symptomatic carotid disease; 13 reported transient ischaemic attacks, while one had had one non-disabling major and several minor strokes corresponding to his carotid stenosis. Figure 1 is a severe symptomatic tandem stenosis of the right internal carotid artery in a 59-year-old patient with two vessel coronary artery disease. The percent diameter stenosis was 56% at the ostial portion

3 Carotid artery stenting 1367 Table 1 Baseline clinical characteristics of patients Age (in years) n Male/Female 42/8 Cardiovascular risk factors Hypertension 31 Diabetes 19 Smoker 23 Hypercholsterolaemia 26 Peripheral artery disease 16 Abdominal aneurysm 1 Cardiac history Prior MI, CABG 23 Rhythm disorder 2 Mitral regurgitation 3 Aortic stenosis 3 CCS class I 9 II 11 III/IV 14 NYHA class I 5 II 14 III/IV 13 Coronary vessel disease Advised for CABG 24 Advised for PTCA 23 Advised for valve replacement+cabg 3 Carotid artery stenoses (n=53) Right internal carotid artery 29 Left internal carotid artery 24 Symptomatic 14 Transient ischaemic attack (TIA) 13 Major stroke 1 Asymptomatic 39 Contralateral carotid occlusion 3 Bilateral stenoses 9 MI=myocardial infarction; CABG=coronary artery bypass graft; CCS=Canadian Cardiovascular Society; NYHA=New York Heart Association; PTCA=percutaneous transluminal coronary angioplasty. and 72% at the distal area, with a 1 4 mm minimum lumen diameter. Figure 2 represents the same stenotic area after the placement of a 6 mm diameter Wallstent. The residual stenosis of the ostial part of the lesion was 12%. After stent placement the patient underwent coronary artery bypass grafting uneventfully. Figure 3 shows the angiogram of the same patient after 7 3 months follow-up. Within the Wallstent, intimal hyperplasia has occurred without a significant degree of restenosis. The on-line quantitative carotid angiography demonstrated a 12% diameter stenosis with a minimum lumen diameter of 3 63 mm. Fifty-three stenosed vessels were treated in 50 patients. In three patients the opposite carotid artery Figure 1 A severe tandem stenosis of the right internal carotid artery in a 59-year-old patient with two-vessel coronary artery disease. The percent diameter stenosis was 56% at the ostial portion and 72% at the distal area with 1 4 mm minimum lumen diameter. was occluded, nine patients had bilateral stenoses, three of them were stented bilaterally. The mean degree of stenosis before intervention was 78 18%; after stenting the mean residual stenosis was 13 11%. The Wallstent was deployed in 42 stenoses. Eight stenoses were treated with BeStents, one lesion was treated with a Palmaz Schatz, two with an AVE-Microstent and three with a Sito stent. One patient with bilateral internal carotid artery stenosis >70% had both arteries stented in one procedure. The temporary pacemaker proved to be an important prophylactic means, since 40 patients developed transient sinoatrial heart block during the high-pressure dilatation. Three patients developed transient ischaemic attacks in the first 24 h after the procedure (Table 2). However, all symptoms resolved without residuals. No patient had myocardial infarction and none displayed creatine kinase elevation. One patient developed a major stroke immediately after the procedure. Since this patient represents a serious complication, we present his case in detail. This patient was 89 years old and had had a non-disabling major and several minor strokes in the last 2 months. He had suffered several myocardial infarctions prior to the procedure, and also had severe three vessel coronary disease with an ejection fraction <30%. His left carotid artery was stenotic and he had experienced two episodes of transient right hemiparesis, which resolved within 3 days. Neither cardiac nor vascular surgeons were willing to operate on this patient, so we offered him carotid stenting. A computed

4 1368 J. Waigand et al. Figure 2 Digital subtraction angiogram of the same vessel indicated in Fig. 1 after the placement of a 6 mm in diameter Wallstent with a residual narrowing of 12% of the ostial part of the lesion. The patient then underwent coronary artery bypass grafting uneventfully. tomography scan and a cerebral angiogram of the right carotid and right middle cerebral artery were performed prior to stent placement. After stent placement, he developed a left hemiparesis. We decided to examine his carotid circulation again; the stent was patent and the right middle cerebral artery appeared no different from the earlier examination. We also repeated the computed tomography scan immediately and again several days later, and no new hypodense areas were found. The patient subsequently died 2 weeks later. A request for autopsy was denied. Clinical follow-up and duplex scanning was available in 46 patients over a mean of 10 months. Thirty-six patients had angiography. None of the patients reported transient ischaemic attacks and none has had a major stroke. One patient with rhythm disorder developed a non-disabling minor stroke corresponding to the site of stent implantation 6 months after the procedure without significant restenosis. One patient receiving an AVE stent, one with a Wallstent and another with a Palmaz Schatz stent developed restenosis (>50%) at 3, 5 and 6 months during the follow-up. All three were successfully treated with balloon angioplasty. One BeStent showed deformation; however, the resulting stenosis was not significant. Two patients died 2 weeks after successful coronary artery bypass grafting surgery due to rhythm disorder. None of these patients had suffered neurological complication (transient ischaemic attack, minor or major stroke). Figure 3 An angiogram of the same patient after 7 3 months. Within the Wallstent intimal hyperplasia has occurred without a significant degree of restenosis. The on-line quantitative carotid angiography demonstrated a 12% diameter stenosis with a minimum lumen diameter of 3 63 mm. Discussion Our experience indicates that high-risk patients with severe coronary artery disease, three vessel disease and poor ventricular function, can be successfully treated for carotid artery stenosis with a stent implantation. We did not initially intend to perform an observational trial of stent implantation. We conducted the procedure because of the uncertainty of the course of action of treating patients with severe concomitant coronary and carotid atherosclerosis. Patients with concomitant carotid and coronary disease have special problems. Stroke is estimated to occur after coronary artery bypass grafting in 1 6% of patients [9]. Risk factors for postoperative stroke include a history of neurological deficit, congestive heart failure, mitral insufficiency, or the presence of a carotid artery bruit [10]. Thus, there are no guidelines based on prospective trials indicating how such patients are best managed. Recent studies suggested that the neurological risk for patients undergoing bypass surgery is greater than generally appreciated [11]. Patients with severe carotid disease, asymptomatic or not, are at a higher risk of developing such complications post-operatively than patients without. The incidence of adverse cerebral outcomes increases dramatically in patients older than 69 years. Moreover, advanced age, particularly an age of 70 or more, is a leading factor for neurological complications associated with coronary artery bypass grafting [11].

5 Carotid artery stenting 1369 Table 2 Procedural results, follow-up and complications in 50 patients Stenoses 53 Severity before stent* 78 12% Severity after stent* 13 11% Stents 56 Wallstent 42 Palmaz Schatz 1 AVE stent 2 Sito stent 3 BeStent 8 Complications after stent Procedural events TIA 3 Minor stroke 1 Major stroke 1 Postprocedural events (at discharge) Death 1 Postprocedure events (at 30 days) Death, major or minor stroke, TIA 0 Complications after CABG Death 2 TIA 0 Minor or major stroke 0 Complications after PTCA Myocardial infarction 0 TIA, major or minor stroke 0 Follow-up (at 6 month) Restenosis 3 Minor stroke 1 Stent deformation 1 TIA=transient ischaemic attack; CABG=coronary artery bypass graft; PTCA=percutaneous transluminal coronary angioplasty. *stenosis quantification according to NASCET criteria [8]. The American Heart Association Ad Hoc committee could identify no proven indication for carotid endarterectomy in asymptomatic patients with coronary artery disease [9]. The committee concluded that carotid endarterectomy appeared acceptable, but unproved for those patients with a stenosis 75% and an estimated surgical risk below 3%. The peri-operative stroke rate in the North American Endarterectomy Trial was 5 8% [8] ; the European trial gave similar results [12]. Peri-operative mortality amounted to 0 6% and was mainly due to myocardial infarction. However, in angina pectoris patients, mortality rates following carotid endarterectomy of 4 18% have been reported [13]. None of the patients reported here would have qualified for either of these trials because of the studies exclusion criteria. In conclusion, at the present time, guidelines for adequate treatment of both symptomatic and asymptomatic carotid artery stenoses are vague for patients with symptomatic coronary atherosclerosis. Thus, the question remains how patients with severe coronary artery disease and carotid artery stenosis should be treated. Staged surgical procedures, either coronary artery bypass grafting first, followed by carotid n endarterectomy or vice versa, appear to be associated with an increased risk of ischaemic peri-operative complications. In the case of carotid endarterectomy as the initial operation, the major risk stems from underperfusion in the coronary vascular bed beyond preexisting critical stenoses. On the other hand, patients with carotid disease undergoing coronary artery bypass grafting are exposed to situations during extracorporal circulation in which cerebral perfusion is severely limited by their carotid stenoses. Whether or not a combined surgical revascularization approach can successfully address these problems is uncertain [6,7]. The stent procedure offers several potential advantages. In contrast to carotid endarterectomy, the antiplatelet regimen can be continued and abrupt changes in blood pressure be avoided. When acute myocardial ischaemia occurs during the procedure, intra-arterial access is provided and immediate angioplasty can be performed. General anaesthesia is not required. Operative treatment does not provide the same flexibility. Cranial nerve palsies are not likely to occur following stenting. The procedure does not need to be restricted to the cervical portion of the carotid artery. The vertebral arteries are also potentially accessible. Finally, as our patients demonstrate, the elderly patient with severe co-morbid vascular problems elsewhere can be offered an alternative. We subsequently also offered this treatment to patients who were advised to undergo high risk percutaneous coronary angioplasty. The high rate of percutaneous coronary angioplasty as a second procedure (instead of coronary artery bypass grafting for revascularization of the underlying three-vessel disease) points to the fact that co-morbidity, advanced age and higher risk in our patient population have contributed to the decision of the cardiac surgeon against a primary surgical approach. Therefore, our main goal was to demonstrate that stent implantation into the carotid artery could be an alternative for a patient with combined morbidity. Although not performed simultaneously, our staged revascularization procedure appears to be safe and not associated with an increased risk of ischaemic complications from either vascular bed. We treated a small number of patients with generalized arteriosclerosis, left ventricular dysfunction after coronary artery bypass grafting, valvular or rhythm disorder. These patients, with an underlying disease likely to be associated with embolic stroke, and general symptoms of carotid disease, fulfilled the North American Endarterectomy Trial exclusion criteria and were not candidates for carotid endarterectomy. We are aware of the concern about safety of carotid angioplasty. As any new therapy it has to be evaluated critically by means of prospective randomized clinical trials as a combined effort of neurologists, interventional neuroradiologists, vascular surgeons and cardiologists. Beebe et al. [14] emphasized that the procedure had been reported only in small published series characterized by lack of complete descriptive

6 1370 J. Waigand et al. information and absent or limited outcome and follow-up data. They pointed out that legal and ethical considerations had not been adequately met and called for well-controlled, scientifically valid, prospective clinical trials. Their concerns are obviously important and reasonably stated. We attempted to meet at least some of the issues they raised by providing independent qualified neurological assessment, adequate carotid imaging, brain imaging, interdisciplinary peer review, and careful follow-up. Although we fully agree with the call for a randomized prospective trial, we predict that the patients treated here might not qualify for randomization because of their concomitant medical problems. Since the editorial of Beebe et al. [14] observational studies have been reported, in which excellent follow-up data and documentation were available. Yadav et al. [15] treated 107 patients with elective stenting of extracranial carotid arteries. They reported seven minor strokes, two major strokes, and one death during the first 30 days after the procedure. Their patients also exhibited multimorbid vascular problems elsewhere. The group has subsequently expanded its experience to additional patients [16] ; however, the conclusions are the same. On the basis of their observational study, carotid artery stenting appears to offer severely ill patients an alternative to vascular surgery or remaining untreated. Our experience supports their point of view. Grotta [17] pointed out that the experience of Yadav et al. [15] might offer an alternative to carotid endarterectomy. However, he further emphasized important differences in coronary and carotid atherosclerosis, particularly the tendency of carotid plaques to result in distal embolization. We also had one death. Our patient had severe generalized vascular disease and in retrospect should probably have been left untreated. However, repeat angiography and computed tomography examinations did not reveal evidence for a major technical problem; the stent was well placed and the middle cerebral artery was not occluded. We treated most of our patients with selfexpanding Wallstents. The major advantage of the Wallstent in our view is reduced recoil and decreased chances for subsequent stent deformation. The latter stent-related complication has been described by Yadov et al. with the Palmaz stent [9]. We observed only one stent deformation in a BeStent without significant restenosis. In conclusion, we agree that only randomized, prospective trials can establish carotid angioplasty with stent implantation as a reasonable, safe alternative to carotid endarterectomy and we intend to participate in such studies. In a small but ever increasing high risk patient population with severe coronary artery disease and concomitant carotid stenosis 70% we feel that based on our experience carotid stenting is feasible and safe and might be indicated as an alternative procedure to combined carotid and coronary surgery. References [1] Yusuf S. Effect of coronary artery bypass graft surgery on survival: overview of 10 year results from randomized trials by the coronary artery bypass graft surgery trialists collaboration. Lancet 1994; 344: [2] Ropper AH, Wechsler LR, Wilson LS. Carotid bruit and the risk of stroke. N Engl J Med 1982; 307: [3] Brener BJ, Brief DK, Alpert J et al. The risk of stroke in patients with asymptomatic carotid stenosis undergoing cardiac surgery; a follow-up study. J Vasc Surg 1987; 5: [4] Barnes RW. Asymptomaic carotid disease in patients undergoing major cardiovascular operations: Can prophylactic endarterectomy be justified? Ann Thorac Surg 1986; 42: S36 S40. 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