Stroke in Patients Undergoing PCI
Abstract & Commentary
By Andrew J. Boyle, MBBS, PhD, Assistant Professor of Medicine, Interventional Cardiology, University of California, San Francisco. Dr. Boyle reports no financial relationship relevant to this field of study.
This article originally appeared in the June 2011 issue of Clinical Cardiology Alert. It was edited by Michael H. Crawford, MD, and peer reviewed by Ethan Weiss, MD. Dr. Crawford is Professor of Medicine, Chief of Clinical Cardiology, University of California, San Francisco, and Dr. Weiss is Assistant Professor of Medicine, Division of Cardiology and CVRI, University of California, San Francisco. Dr. Crawford is a speaker for Astra-Zeneca, and Dr. Weiss reports no financial relationships relevant to this field of study.
Source: Hoffman SJ, et al. Trends, predictors, and outcomes of cerebrovascular events related to percutaneous coronary intervention. A 16-year single-center experience. J Am Coll Cardiol Intv 2011;4:415–422.
Cerebrovascular events (CVE), including stroke and transient ischemic attack (TIA), are recognized complications of percutaneous coronary intervention (PCI). Recent years have seen refinements in PCI techniques that have allowed older and sicker patients to undergo PCI. At the same time, improvements in antithrombotic and antiplatelet medications have reduced the ischemic coronary complications of PCI. Whether these changes have altered the risk of CVE in patients undergoing PCI is not known. Accordingly, Hoffman and colleagues examined the Mayo Clinic database of 24,126 PCI hospitalizations between 1994 and 2009 to determine the temporal trends in the incidence and predictors of CVE, as well as the outcomes in patients who suffer CVE following PCI.
The authors compared patients undergoing PCI based on whether they did or did not suffer a CVE during the hospitalization. There were numerous differences in the baseline demographics between those who suffered a CVE and those who did not. Those who suffered a CVE were older (74 ± 11 years vs. 66 ± 12 years, P < 0.001), more likely to be female (51% vs. 29%, P < 0.001), have had a recent myocardial infarction (MI; 60% vs. 32%, P < 0.001) or pre-procedural shock (11% vs. 4%, P < 0.001), have a history of prior CVE (32% vs. 11%, P < 0.001), or renal failure (8% vs. 4%, P < 0.05). Interestingly diabetes, dyslipidemia, and congestive heart failure (CHF) were not associated with an increased risk for CVE. Angiographic and procedural variable also differed between groups. Those who suffered a CVE had more diseased vessels and more vessel segments treated, higher incidence of visible thrombus (55% vs. 31%, P < 0.001), higher rates of intra-aortic balloon pump use (6% vs. 2%, P = 0.03), and were more likely to be undergoing PCI for emergent indications (40% vs. 19%, P < 0.001). The use of glycoprotein IIb/IIIa inhibitors, unfractionated vs. low molecular weight heparin, and radial vs. femoral approaches were not associated with the occurrence of CVE.
The incidence of CVE was 0.37%, of which 78% were stroke and 22% were TIA. Of the strokes, 92% were ischemic, 7% were hemorrhagic, and 1% unknown (no imaging). Over 16 years, the rate of CVE remained similar. The authors performed multivariate analysis and found four independent predictors for CVE (with odds ratio in parentheses): age, per decade (1.47); female gender (1.8); MI within 7 days (2.2); and previous CVE (2.7) (all P < 0.01). Interestingly, the rate of peri-procedural CVE has not changed significantly over the past 16 years. After multivariable adjustment, the rate numerically decreased from approximately 0.6% to 0.3%, but this did not reach statistical significance.
As expected, both short- and long-term outcomes were significantly worse in patients who suffered a CVE. Procedure-related MI, access-site complications, hemodynamic instability, requirement for emergency balloon pump or coronary artery bypass surgery, and post-procedural renal failure were all more likely to occur in patients who suffered CVE. In-hospital mortality was 19% vs. 2% (P < 0.001) and long-term mortality was also significantly higher (P < 0.01). The authors conclude that the incidence of PCI-related CVE has remained steady over a 16-year period, despite an increase in baseline risk profile. Age and prior history of CVE were the strongest independent demographic predictors. PCI-CVE had a markedly adverse impact on early and late outcomes.
Stroke remains perhaps the most devastating complication of PCI. In assessing a patient's risk for invasive therapies such as PCI, an accurate assessment of the likelihood of complications is paramount. This study gives us pertinent information to relay to our patients in deciding on whether or not to pursue PCI. The four independent predictors of CVE identified by Hoffman and colleagues (age, female gender, recent MI, and previous CVE) identify the highest risk patients. In fact, the risk of PCI-related CVE is 9-fold higher in an octogenarian than a patient younger than 50 years of age, and in an octogenarian with prior CVE it is 19-fold higher than a younger patient without prior CVE. With such dramatic differences in the rate of CVE, it is paramount that we accurately counsel our patients on their individual risk.
This study is limited by its retrospective observational nature. Thus, no changes in management based on these observations can be recommended at this time. In addition, we are not provided with information on the level of anti-coagulation during the procedure, the procedure length, or the rate of atrial fibrillation. All these factors, and others, may influence the rate of CVE. Thus the dataset in not complete. However, this study improves our ability to individualize risk assessment for an individual who is considering PCI, based on clinical factors before going to the cath lab, and may therefore improve our clinical decision-making.