Comparison of clinical outcome following coronary stenting or balloon angioplasty in dialysis versus non-dialysis patients

Abstract

W coronary stenting has been shown to reduce acute closure and 6-month restenosis in humans,1,2 few data on angioplasty and stenting are available in dialysis patients. The purpose of the current study was to determine the influence of dialysis: (1) on in-hospital outcome after balloon angioplasty with stent or without coronary stenting, and (2) on 1-year clinical outcome after coronary stenting or balloon angioplasty with ,30% residual stenosis. • • • The patient cohort included a consecutive series of 1,201 patients (1,363 narrowings) treated with balloon coronary angioplasty with or without coronary stenting between January 1995 and June 1998. Baseline clinical and angiographic characteristics, procedural results, and in-hospital complications had been entered prospectively into a computerized database. Patients were divided into 4 groups according to the use of stent during the procedure, and according to dialysis for at least 90 days before coronary angioplasty. There were 864 non-dialysis patients (72%) without coronary stenting, 250 non-dialysis patients (21%) with coronary stenting, 60 dialysis patients (5%) without coronary stenting, and in 27 dialysis patients (2%) with coronary stenting. The high percentage of patients with end-stage renal disease was due to an association with a renal disease program. The cause of renal failure was diabetes in 18%, hypertension in 23%, and other conditions in 59%. All patients were treated and studied after giving informed consent. All patients underwent left ventriculography and coronary angiography in multiple projections. Percutaneous transluminal coronary angioplasty was performed using standard techniques and adjunctive therapy, as previously described.3 All patients received aspirin 250 mg/day and a bolus of heparin (100 IU/kg) just before angioplasty. Indications for stenting included elective or provisional use following a bailout or a suboptimal result with residual stenosis exceeding 30% after balloon angioplasty. Procedural success was defined as diameter stenosis reduction of .20% with a residual stenosis ,50%, in the absence of major complications including death, myocardial infarction, and need for emergency surgery. Myocardial infarction was defined by increased serum creatine phosphokinase level .3 times the upper limit of normal, with $10% creatine phosphokinase-MB values relative to the total creatine phosphokinase. Vascular complications included hematoma requiring a blood transfusion or false aneurysm requiring surgical repair or prolonged compression. The poststent antithrombotic treatment included ticlopidine (500 mg/day), begun immediately after the procedure and continued for 4 weeks, and aspirin (100 mg/day for 4 weeks and then 250 mg/day). The qualitative angiographic analyses were performed independently by 2 experienced interventional cardiologists. Disagreements were resolved by consensus. Quantitative angiographic analyses were performed using digital computed-assisted calipers (DCI Philips, CAAS System, Eindhoven, Holland). The degree of stenosis before and after angioplasty was measured after intracoronary injection of sin-1 (linsidomine, 1 mg) in the view showing the most severe stenosis and expressed as the minimal luminal diameter and the linear percent luminal diameter reduction using the average diameter of the nearest normal segment as reference. Long-term follow-up data were obtained by serial telephone interviews. Late clinical events were corroborated by primary source documentation. Control angiography was restricted to patients with recurrence of limiting symptoms or severely documented ischemia, or both. Restenosis was diagnosed when a $50% diameter narrowing was found at the site of the previous dilation. Indications for a new revascularization procedure were divided between restenosis at a site of previous dilation and the appearance of a new significant coronary artery stenosis not present on the initial angiogram. Continuous variables are presented as means 6 1 SD. Categorical data are presented as percent frequencies. Univariate analyses were performed using the chi-square test for categorical data and analysis of variance for continuous variables. Multiple logistic regression and stepwise logistic regression analyses were performed in the standard manner. A multivariate, stepwise, logistic regression analysis that included clinical, angiographic, and hemodynamic baseline variables (Table I) was used to identify the best set of predictors for procedural failure and for the occurrence of in-hospital complications or major cardiac events during follow-up. A p value ,0.05 was considered significant. Dialysis patients were younger, more often hyperFrom the Service de Cardiologie, Hopital Necker, Service de Nephrologie, Hopital Saint Louis, and Service de Nephrologie, Hopital Necker, Paris, France. Dr. Le Feuvre’s address is: Cardiologie, Hopital Necker, 149 rue de Sevres, 75015 Paris, France. Manuscript received September 13, 1999; revised manuscript received and accepted December 9, 1999.