Metabolic Syndrome Is Associated With Worse Outcomes After SFA Intervention

NAPLES, FLA. – Presence of metabolic syndrome is a risk factor for poor outcomes during superficial femoral artery interventions, according to a retrospective database study.

Although approximately half of patients with peripheral artery disease also have metabolic syndrome, its impact on peripheral interventions is not unknown, Dr. Christopher J. Smolock said at the annual meeting of the Southern Association for Vascular Surgery.

To find out more, Dr. Smolock and his associates reviewed a database of 870 patients who underwent endovascular treatment for symptomatic superficial femoral artery (SFA) disease. In this study, 46% of patients met criteria for metabolic syndrome, the average age was 67 years, and 64% were men.

A total 1,006 limbs of these patients were treated between 1999 and 2009 at the DeBakey Heart and Vascular Center at the Methodist Hospital in Houston. The researchers compared patient factors at presentation and outcomes between patients without metabolic syndrome (542 treated limbs) and patients with the syndrome (464 treated limbs).

Limbs in the metabolic syndrome group were significantly more likely to come from women (44% vs. 31%), to come from patients with critical ischemia symptoms of pain at rest and tissue loss (54% vs. 38%), and to feature more advanced SFA lesions (51% vs. 31%), compared with limbs in the group without metabolic syndrome.

Claudication was a presentation for 46% of the limbs in the group with metabolic syndrome versus 62% of limbs in the non–metabolic syndrome group.

The investigators compared 30-day mortality and morbidity between these groups. In addition, they assessed the 5-year rates for primary and secondary patency; freedom from recurrent symptoms; and limb salvage. “We wanted to look at metabolic syndrome’s effect on these outcomes,” said Dr. Smolock of the DeBakey Heart and Vascular Center.

“This addresses the important topic of outcomes with SFA interventions in those with metabolic syndrome,” said study discussant Dr. Scott L. Stevens. “Of note, mortality was not increased among those with metabolic syndrome.” Dr. Stevens is a vascular surgeon at the University of Tennessee Medical Center in Knoxville.

There was no significant difference in 30-day mortality: 0.2% in the metabolic syndrome group and the 1.3% in the nonsyndrome group.

A lower percentage of the metabolic syndrome group, 67% vs. 73%, experienced freedom from recurrent symptoms over 5 years.

“Primary patency decreased as well significantly over 5 years in those with metabolic syndrome,” Dr. Smolock said. The study revealed 56% of the metabolic syndrome group had 5-year primary patency, compared with 66% in unaffected group; 71% vs. 78% had assisted primary patency; and 71% vs. 78% had secondary patency. Secondary patency decreased also, but there was no significant difference between groups, he added.

Because critical ischemia more often affected the group with metabolic syndrome, the rate of limb amputation was higher in this group (22% versus 13% of the unaffected group at 5 years).

Dr. Stevens asked why the metabolic group experienced significantly higher morbidity but not mortality, compared with the unaffected group. This might be because the mortality figures were calculated for only the first 30 days and not over the 5 years, Dr. Smolock said. In addition, the low 30-day mortality “could speak to this being a local procedure, not [one] done under general anesthesia.” He added, “I hope some of that has to do with our risk-reduction strategies preoperatively.”

“What changes have you made in your practice to reduce risk factors in those patients with metabolic syndrome?” Dr. Stevens asked.

“Our beta blocker, statin, and aspirin use were not at levels we wanted,” Dr. Smolock replied. So use of these agents is now prescribed for all patients without a contraindication, he said.

Dr. Stevens also asked if metabolic syndrome might just be a surrogate for patients with smaller arteries and/or more plaque. “I don’t think this is because of small or poor targets,” Dr. Smolock said. “The SVS [Society for Vascular Surgery] runoff score was equal between the groups. Diabetes is a risk in and of itself for small or poor targets, but it’s not something we could see anatomically.”

Metabolic syndrome was defined in this study using the National Heart, Lung and Blood Institute/American Heart Association criteria. Therefore, patients had to have three or more of the following: systolic blood pressure of 130 mm Hg or greater/diastolic blood pressure of 85 mm Hg or greater; triglycerides of 150 mg/dL or greater; HDL cholesterol of 50 mg/dL or lower for women or 40 mg/dL or lower for men; fasting blood glucose of 110 mg/dL or greater; or body mass index of 30 kg/m2 or greater.

Dr. Smolock said that he had no relevant disclosures.