Survival benefits of revascularization in patients with critical limb ischemia and renal insufficiency.
BACKGROUND
Evidence for the best treatment strategy for patients with critical limb ischemia (CLI) at different stages of renal insufficiency (RI) is rare. Therefore, we determined the benefit of revascularization vs medical therapy (MT) only in CLI patients with different levels of RI.


METHODS
This intention-to-treat cohort study with follow-up at 2, 6, and 12 months was conducted in a consecutive series of 351 patients with CLI. Revascularization by surgical (78 patients) or endovascular techniques (191 patients) was performed in 269 patients. MT as first-line therapy was administered in 82 patients. Patients were grouped according to glomerular filtration rate (GFR), estimated with the Modification of Diet in Renal Disease equation, into absent/mild RI (estimated GFR [eGFR], ≥ 60 mL/min/1.73 m(2)), moderate RI (eGFR, 30-59 mL/min/1.73 m(2)), and severe RI (eGFR, <30 mL/min/1.73 m(2) or dialysis). Primary outcome measures were overall and amputation-free survival. Cox regression models adjusted for baseline characteristics after Kaplan-Meier survival estimates were performed.


RESULTS
The mean age differed significantly between groups (P < .001), and patients with absent/mild RI were more often men (P < .001) or smokers (P < .001) and less often hypertensive (P < .001). Risk factor adjustment showed that revascularized CLI patients with absent/mild RI had a longer amputation-free survival (hazard ratio [HR], 0.46; 95% confidence interval [CI], 0.26-0.82; P = .008), higher limb salvage (HR, 0.29; 95% CI, 0.17-0.91; P < .029), and better clinical success than MT patients (HR, 0.33; 95% CI, 0.17-0.65; P = .001). The moderate RI group benefited from revascularization in overall survival (HR, 0.51; 95% CI, 0.26-0.99; P = .049), amputation-free survival (HR, 0.51; 95% CI, 0.29-0.90; P = .020), and clinical success (HR, 0.42; 95% CI, 0.22-0.80; P = .008). A beneficial effect on overall survival was found even in patients with severe RI when revascularized (HR, 0.33; 95% CI, 0.12-0.91; P = .032 vs MT).


CONCLUSIONS
Patients with CLI may benefit from revascularization compared with MT alone at all levels of renal impairment. Thus, revascularization should not be withheld in CLI patients at any level of RI.
Department of Clinical and Interventional Angiology, Swiss Cardiovascular Center, Bern University Hospital, Bern, Switzerland. jana.ortmann@dkf.unibe.ch
Jana
J
Ortmann
Brigitta
B
Gahl
Nicolas
N
Diehm
Florian
F
Dick
Tobias
T
Traupe
Iris
I
Baumgartner
D000368:Aged; D000369:Aged, 80 and over; D000671:Amputation, Surgical; D016009:Chi-Square Distribution; D016638:Critical Illness; D057510:Endovascular Procedures / Q000009:adverse effects / Q000401:mortality*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007511:Ischemia / Q000401:mortality* / Q000601:surgery / Q000628:therapy*; D053208:Kaplan-Meier Estimate; D007668:Kidney / Q000503:physiopathology; D023821:Limb Salvage; D016014:Linear Models; D016015:Logistic Models; D035002:Lower Extremity / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D018579:Patient Selection; D016016:Proportional Hazards Models; D011446:Prospective Studies; D051437:Renal Insufficiency / Q000150:complications / Q000401:mortality* / Q000503:physiopathology; D012086:Reoperation; D018570:Risk Assessment; D012307:Risk Factors; D013557:Switzerland; D013997:Time Factors; D016896:Treatment Outcome; D014656:Vascular Surgical Procedures / Q000009:adverse effects / Q000401:mortality*