Peripheral arterial disease in the catheterization laboratory: an underdetected and undertreated risk factor.

See also page 1113 Patients undergoing percutaneous coronary revascularization present an opportunity for physicians to focus on risk factor identification and treatment. Although strides have been made in the treatment of some risk factors such as hyperlipidemia, surprisingly, peripheral arterial disease (PAD) continues to be ignored as a risk factor in cardiology. It is embarrassing to think that patients may undergo canalization of their femoral arteries and angiography of their coronary arteries with no real thought given to the ascertainment of arterial disease in noncoronary segments. In the current issue of the Mayo Clinic Proceedings, Singh et al call attention to the prevalence of manifest PAD in the percutaneous coronary intervention (PCI) population—18%—a number worthy of our notice. Furthermore, the in-hospital and long-term outcomes of patients with PAD are substantially worse than the outcomes of patients without PAD. This study, which included 1397 patients with PAD, is one of the largest of its kind. Identification of PAD serves several useful purposes. Singh et al show that PAD identifies a patient population at particular risk of ischemic complications in both the short term and long term. In-hospital mortality rates were 3 times higher in patients with PAD compared with those without PAD—an important observation by Singh et al. Rates of inhospital myocardial infarction, stroke, and transient ischemic attack were also higher, whereas rates of procedural success were lower. Other studies in contemporary PCI literature have corroborated this elevated risk for patients with PAD. Despite the fact that PAD poses a specific hazard to patients undergoing PCI, it is encouraging that Singh et al found that results of PCI have improved in recent years. This is due in large part to routine coronary stenting and superior generations of stents that are easier to deploy. Advances in pharmacotherapy such as intravenous glycoprotein IIb/IIIa inhibition and clopidogrel also have contributed to this improvement. Ongoing advances such as the incorporation of drug-eluting stents into routine practice will likely further improve the results obtained with PCI in patients with PAD, although this is unlikely to eliminate the gap between patients with and without PAD on end points such as death. The rates of stroke as a complication of PCI were extremely low in this study; however, it is notable that the rate of stroke was twice as high in patients with PAD (0.6%), emphasizing again the need for special care during catheterization of patients with PAD. Use of smaller-diameter catheters and exchange length wires for all catheter exchanges may help minimize the embolic potential in patients with PAD. Also, patients with PAD who undergo PCI have a higher risk of bleeding complications. Singh et al report a risk of bleeding that is essentially doubled with PAD, with a transfusion rate of 11% vs 5.8%. Vascular access may be more complicated due to the presence of atherosclerosis and calcification in the artery being punctured. Potentially, improvements in adjunctive pharmacotherapy such as use of the direct thrombin inhibitor bivalirudin instead of heparin could minimize this bleeding hazard in patients with PAD. More effective methods to provide hemostasis after arterial sheath removal also are being explored. Singh et al are to be commended for the comprehensive definition of PAD used in their study, which includes disease of the cranial and extracranial arteries, abdominal aortic aneurysm, and lower extremity arterial disease. It is appropriate that cerebrovascular disease be included in this definition. Indeed, the patient with involvement of 1 arterial bed has a high likelihood of either symptomatic or asymptomatic involvement of another arterial bed, and this global approach to atherothrombosis is the direction in which the field is heading.