Larry A. Scher

Statin use and other factors associated with mortality after major lower extremity amputation

Objective: Above‐knee amputations (AKAs) and below‐knee amputations (BKAs) are associated with high postoperative mortality rates. In this study, we examined factors associated with 30‐day, 90‐day, and 1‐year mortality in patients who underwent a major lower extremity amputation. Methods: We queried a prospectively collected institutional database for all patients who underwent AKA or BKA with primary or secondary closure, during a 5‐year period, between November 2009 and November 2014. Predictors of 30‐ and 90‐day mortality were determined by multivariable logistic regression, and risk indexes for 1‐year mortality were determined with Cox proportional hazards model. Results: We identified 811 patients who underwent AKA (n = 325) or BKA (n = 486). The 30‐day mortality was 8.4% (AKA, 13.5%; BKA, 4.9%; P < .001) and 90‐day mortality was 15.4% (AKA, 24.3%; BKA, 9.45%; P < .001). Predictors of 30‐day mortality included AKA (odds ratio [OR], 3.09; 95% confidence interval [CI], 1.76‐5.53), emergency operation (OR, 2.86; 95% CI, 1.56‐5.14), chronic obstructive pulmonary disease (OR, 3.09; 95% CI, 1.07‐7.81), end‐stage renal disease (ESRD) on hemodialysis (HD; OR, 2.35; 95% CI, 1.24‐4.33), and chronic kidney disease stages 3 (OR, 1.84; 95% CI, 1.00‐3.37) and 4 (OR, 2.33; 95% CI, 1.01‐4.98). Predictors of 90‐day mortality included age (OR, 1.02; 95% CI, 1.00‐1.04), ESRD on HD (OR, 2.56; 95% CI, 1.55‐4.22), AKA (OR, 2.61; 95% CI, 1.70‐4.05), history of coronary artery bypass grafting (OR, 2.04; 95% CI, 1.06‐3.87), and medium‐intensity or high‐intensity statin (OR, 0.46; 95% CI, 0.29‐0.73). One‐year survival for the overall cohort was 73.7% (95% CI, 70.8%‐76.8%). Predictors of 1‐year mortality included AKA (hazard ratio [HR], 2.07; 95% CI, 1.54‐2.77), coronary artery bypass grafting (HR, 1.57; 95% CI, 1.07‐2.32), age >70 years (HR, 1.39; 95% CI, 1.02‐1.88), gangrene (HR, 1.44; 95% CI, 1.07‐1.94), ESRD on HD (HR, 1.96; 95% CI, 1.42‐2.70), chronic obstructive pulmonary disease (HR, 2.54; 95% CI, 1.52‐4.25), Caucasian race (HR, 1.62; 95% CI, 1.18‐2.22), history of open lower extremity revascularization (HR, 0.71; 95% CI, 0.51‐1.00) and undergoing bilateral amputations (HR, 2.10; 95% CI, 1.06‐4.15). In the year after amputation, medium‐intensity statin (HR, 0.64; 95% CI, 0.47‐0.87) and high‐intensity statin (HR, 0.56; 95% CI, 0.33‐0.95) conferred a mortality benefit. Low‐intensity statins did not confer protection from mortality. At 1 year after amputation, only 44.7% of patients were receiving appropriate statin therapy. Conclusions: AKA and BKA have historically been associated with high mortality rates. Medium‐intensity and high‐intensity statin therapies were associated with a mortality benefit at 1 year. We have identified initiation of statin therapy in this high‐risk population as a gap in patient care.

Factors Associated with Ipsilateral Limb Ischemia in Patients Undergoing Femoral Cannulation Extracorporeal Membrane Oxygenation

BACKGROUND Extracorporeal membrane oxygenation (ECMO) is an important life-saving modality for patients with cardiopulmonary failure. Vascular complications, including clinically significant limb ischemia, may occur as a result of femoral artery cannulation for venoarterial (VA) ECMO. This study examines our institutional experience with femoral VA ECMO and the development of ipsilateral limb ischemia. METHODS We performed a retrospective review of all consecutive patients undergoing femoral VA ECMO between 2011 and 2016. The primary endpoint was clinical evidence of limb-threatening ischemia. Multivariate logistic regression analysis was used to identify predictors for limb ischemia after cannulation. RESULTS Between March 2011 and September 2016, 154 patients underwent femoral cannulation for VA ECMO. Overall in-hospital mortality was 59.7%. Clinically significant ipsilateral limb ischemia occurred in 34 (22%) patients; 7 required four-compartment fasciotomy, and 3 of these patients required amputation. On univariate analysis, a history of pulmonary disease, peripheral arterial disease, and stroke or transient ischemic attack was significantly associated with clinical limb ischemia. On multivariate analysis, younger age (odds ratio [OR], 0.96; 95% confidence interval [CI], 0.93-0.99), diabetes (OR, 2.77; 95% CI, 1.08-7.12), pulmonary disease (OR, 3.86; 95% CI, 1.38-10.78), and peripheral arterial disease (OR, 13.68; CI, 2.75-68.01) were associated with limb ischemia. Lack of prophylactic distal perfusion catheter and arterial cannula size were not independently associated with limb ischemia. CONCLUSIONS Femoral ECMO cannulation can be associated with significant limb ischemia necessitating surgical intervention. Younger patients, as well as those with a history of diabetes, pulmonary disease, and peripheral arterial disease, may be at increased risk for this complication.