In their article in the December issue of Vascular Disease Management, Drs. Lee and Akhondi question whether or not routine coronary angiography should be performed in all patients presenting with critical limb ischemia (CLI). The article cites the high mortality rates associated with CLI that are driven predominately by myocardial infarction and stroke. The authors also note the high incidence of asymptomatic coronary presentation related to advanced age, diabetes, and poor exercise capacity (all of which may mask exertion induced angina). They add that in the Coronary Artery Revascularization Prophylaxis (CARP) study, two-thirds of the CLI patients were found to have coronary artery disease. Of the 145 patients in whom coronary disease was discovered, 114 had large areas of myocardium at risk that were treated with coronary artery intervention. At 1 year the entire cohort of patients (those with and without CAD) had lower than typical mortality rates (7.1% in the group with CAD and 4.7% in the group with no CAD, which was not statistically different). Dr. Lee does not cite the rate of complications or the associated cost of routine coronary angiography.
This has profound implications for the pre-operative and pre-interventional assessment of CLI. The findings may apply to other disorders, such as abdominal aortic aneurysms for which there is high associated cardiovascular mortality despite successful aneurysm repair. To become the standard of care, cost-to-benefit ratio and associated risk must be evaluated for routine coronary angiography. Risk may not be inconsequential in patients with advanced age or substantial renal dysfunction. Clearly more studies including detailed cost-benefit and stratified risk analyses are warranted.
This article highlights the close association of CLI with other advanced cardiovascular disorders that are typically causal of the high associated mortality. I think that it underscores the immediate and, in my opinion, the indisputable need for aggressive medical therapy in all of these patients. This medical therapy should include at a minimum smoking cessation, hypertension control, lipid management, and optimized diabetic control, including medications known to lessen the development of renal dysfunction. Routine structured follow-up is mandatory.
Compared to patients who present with myocardial infarction or unstable angina, PAD patients in general are less likely to have optimized medical therapy in which guidelines are achieved. Vascular experts must become cardiovascular experts and treat the “whole patient” if we are to have not just procedural success but overall patient success. More study is needed to determine if routine coronary angiography should be the standard of care but no further studies are necessary to mandate better medical therapy and follow-up as mandatory.