How Safe Is Carotid Angioplasty and Stenting in NASCET-Ineligible Patients?
To the Editor:
In a recent article, Malek et al1 reported 3.6% risk of stroke and death after percutaneous transluminal carotid angioplasty and stenting (PTCAS) in symptomatic patients ineligible for carotid endarterectomy (CEA) according to North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria.2 The authors achieved highly successful results in a subgroup of patients who were at high risk of surgical complications.
We conducted a retrospective, independent, third-party audit of medical records of patients undergoing PTCAS in a teaching hospital of University of Toronto. From 1996 to 1999, 55 PTCAS were performed in 50 patients with high-grade (>60%) internal carotid artery (ICA) stenosis. Mean age of patients was 68±11 years, and there were twice as many males; 45% of patients had hypertension, 33% had diabetes, 88% had coronary artery disease, and 36% had contralateral ICA occlusion.
Thirty-three patients were symptomatic and 17 had asymptomatic ICA disease. According to NASCET criteria,2 28 symptomatic patients were ineligible for CEA, leaving 5 patients eligible for carotid surgery. The major reason for NASCET ineligibility was unstable angina (n=14), followed by age >80 years (n=5) and previous CEA (n=5); 2 patients were unstable neurologically, 1 patient had cancer; and 1 patient had unstable congestive heart failure.
In the NASCET-ineligible cohort, there were 3 nonfatal periprocedural strokes (10.7%) and 2 deaths (7.1%), with a combined complication rate of stroke and death of 17.8%. Of 3 nonfatal strokes, 2 were major (Rankin scores of 4 and 5), and 1 patient had minor stroke (Rankin score 1). The cause of death in both cases was stroke: 1 patient developed stroke immediately after a procedure, and another patient had fatal stroke at day 6. In patients with periprocedural complications, the major reason for NASCET ineligibility was age >80 years. Only a 77-year old male patient with minor periprocedural stroke was rejected from CEA because of unstable angina. No complication was observed in 5 patients who were eligible for CEA.
We found an almost 5 times higher periprocedural risk of stroke and death associated with PTCAS in patients compatible to a cohort reported by Malek et al.1 In our population, the major cause of surgical rejection was unstable coronary artery disease (50%), whereas in the cohort reported by Malek et al,1 the major condition leading to exclusion from surgery was age >80 years (21%). However, while this was the reason for excluding these patients from NASCET, most surgeons will operate on patients over this age if they are fit for surgery. In view of this, a 21% exclusion rate on the basis of age alone seems rather high. This may relate to the higher procedural complications observed in our series, but none of our patients died from myocardial infarction, and the only cause of death was stroke. It is also possible that our cohort had more severe ICA disease as measured by Sundt and European Carotid Surgery Trial (ESCT)/Rothwell scores of risks3,4; however, because of the retrospective nature of this study, we did not record plaque surface irregularity, which is a major component of those scores.
We believe that the higher complication rate in our series is not related to the technique of PTACS. No complication was documented in a series of PTACS in patients who were eligible for CEA according to NASCET criteria. There were no major differences in the performance of PTCAS, or in postprocedural management of patients, including use of Schneider’s Wallstent, routine administration of heparin, and in postinterventional prescription of clopidogrel or ticlopidine in combination with aspirin. We were unable to demonstrate a “learning curve” in the performance of PTCAS, with less morbidity and mortality in recently performed procedures. The complications were equally distributed through 1996 to 1999.
Finally, we disagree with the author’s conclusion that PTCAS can be performed in high-risk patients rejected by surgeons with a complication rate compatible with published CEA series. In our series, the complication rate of 17.8% was twice that of the most severely affected patients with a Rothwell/ECST score of 5, and with a 5-year risk of stroke about 38%.4 Only a multicenter, randomized clinical trial, in which patients not eligible for CEA will be randomized into medical and PTCAS groups, may address the question of the superiority of PTACS compared with best medical treatment.