Outcomes after first-time lower extremity revascularization for chronic limb-threatening ischemia between patients with and without diabetes.

OBJECTIVE: The effect of diabetes type and insulin dependence on short- and long-term outcomes after lower extremity revascularization for chronic limb-threatening ischemia (CLTI) warrants additional study and more targeted focus. We sought to address this paucity of information by evaluating outcomes in insulin-dependent and noninsulin-dependent patients after any first-time revascularization.
METHODS: We reviewed all limbs undergoing first-time infrainguinal bypass grafting (BPG) or percutaneous transluminal angioplasty with or without stenting (PTA/S) for CLTI at our institution from 2005 to 2014. Based on preoperative medication regimen, patients were categorized as having insulin-dependent diabetes (IDDM), noninsulin-dependent diabetes (NIDDM), or no diabetes (NDM). Outcomes included wound healing; major amputation; RAS events (reintervention, major amputation, or stenosis); major adverse limb events; and mortality. Outcomes were evaluated using χ2, Kaplan-Meier, and Cox regression analyses.
RESULTS: Of 2869 infrainguinal revascularizations from 2005 to 2014, 1294 limbs (646 BPG, 648 PTA/S) fit our criteria. Overall, our analysis included 703 IDDM, 262 NIDDM, and 329 NDM limbs. IDDM patients, compared with NIDDM and NDM patients, were younger (69 vs 73 vs 77 years; P < .001) and more often presented with tissue loss (89% vs 77% vs 67%; P < .001), coronary artery disease (57% vs 48% vs 43%; P < .001), and end-stage renal disease (26% vs 13% vs 12%; P < .001). Perioperative complications, including mortality (3% vs 2% vs 5%; P = .07), did not differ between groups; however, complete wound healing at 6-month follow-up was significantly worse among IDDM patients (41% vs 49% vs 61%; P < .001). IDDM patients had significantly higher 3-year major amputation rates (23% vs 11% vs 8%; P < .001). Multivariable analyses illustrated that compared with NDM, IDDM was associated with significantly higher risk of both major amputation and RAS events after any first-time intervention (hazard ratio, 2.0 [95% confidence interval, 1.1-4.1] and 1.4 [1.1-1.8], respectively). Similar associations between IDDM and both major amputation and RAS events were found in patients undergoing a PTA/S-first intervention (4.1 [1.3-12.6] and 1.5 [1.1-2.2], respectively), whereas IDDM in BPG-first patients was associated with only incomplete wound healing (2.0 [1.4-4.5]). Last, compared with NDM, NIDDM was associated with lower late mortality (0.7 [0.5-0.9]).
CONCLUSIONS: Compared with NDM, IDDM is associated with similar perioperative and long-term mortality but a higher risk of incomplete wound healing, major amputation, and future RAS events, especially after a PTA/S-first approach. NIDDM, on the other hand, is associated with lower long-term mortality and few adverse limb events. Overall, these data demonstrate both the importance of distinguishing between diabetes types and the potential long-term benefit of a BPG-first strategy in appropriately selected IDDM patients with CLTI.