Risk of major amputation or death among patients with critical limb ischemia initially treated with endovascular intervention, surgical bypass, minor amputation, or conservative management

Figures & data

Figure 1. Attrition diagram. CLI, critical limb ischemia; MinAMP, Minor Amputation without a record of PVI or PVS; PAD, peripheral artery disease; PVI, Peripheral vascular interventions; PVS, Peripheral vascular surgery.

Table 1. Patient demographics.

Category	Total	PVI	PVS	MinAMP	Conservative therapy^a
Total patients	52,527	29,798	10,683	5,126	6,920
Age
Mean	68.6	69.1	66.8	66.2	70.9
SD	12.48	12.14	11.55	13.33	13.96
Gender, %
Male	61.5	60.4	64.6	67.9	57.1
Female	38.5	39.6	35.4	32.1	42.9
US Region, %
Northeast	18.3	16.5	19.1	21.7	22.1
North Central	33.9	35.9	32.1	30.7	30.4
South	34.4	34.5	35.2	34.4	32.8
West	12.4	12.2	12.4	12.2	13.7
Missing/Unknown	1.1	1.0	1.2	1.0	1.0
Insurance coverage, %
Commercial	40.3	38.0	46.5	48.6	34.3
Medicare supplemental	59.7	62.0	53.5	51.4	65.7

^a Conservative Therapy—no revascularization or minor amputation in patients with CLI and gangrene.

CLI, critical limb ischemia; PVI, endovascular revascularization; PVS, surgical revascularization; MinAMP, minor amputation without a record of revascularization.

Table 2. Patient comorbidities.

Category	Total	PVI	PVS	MinAMP	Conservative therapy^a
Total patients	52,527	29,798	10,683	5,126	6,920
Elixhauser Comorbidities, %
Congestive Heart Failure	22.9	21.9	17.3	25.7	33.8
Cardiac Arrhythmia	27.9	26.6	23.5	30.4	38.0
Valvular Disease	13.6	13.0	12.5	13.1	18.6
Pulmonary Circulation Disorders	3.9	3.5	2.9	4.5	6.4
Peripheral Vascular Disorders	100.0	100.0	100.0	100.0	100.0
Hypertension (Uncomplicated)	62.7	63.3	62.3	61.0	61.6
Hypertension (Complicated)	17.1	17.2	12.3	20.2	22.1
Paralysis	1.7	1.4	1.4	1.5	3.7
Other Neurological Disorders	6.9	5.8	4.8	6.9	14.5
Chronic Pulmonary Disease	22.9	22.1	25.1	18.5	25.8
Diabetes (Uncomplicated)	48.4	48.8	37.5	67.7	49.3
Diabetes (Complicated)	36.4	35.4	23.6	64.5	39.7
Hypothyroidism	7.7	7.7	6.3	8.0	9.6
Renal Failure	22.8	22.4	14.9	30.3	31.4
Liver Disease	3.8	3.3	3.3	4.9	5.8
Peptic Ulcer Disease (excluding bleeding)	1.2	1.2	1.0	1.1	1.5
AIDS/HIV	0.2	0.2	0.2	0.2	0.3
Lymphoma	0.9	0.8	0.8	1.1	1.3
Metastatic Cancer	1.2	1.0	1.2	1.3	2.0
Solid Tumor without Metastasis	7.8	7.6	7.7	6.7	9.3
Rheumatoid Arthritis Collagen	6.2	5.9	5.7	6.6	7.9
Coagulopathy	4.9	4.3	3.9	6.7	8.2
Obesity	4.8	4.4	3.7	7.9	6.0
Weight Loss	5.0	3.8	3.8	5.5	11.8
Fluid and Electrolyte Disorders	16.8	14.7	12.7	21.0	29.5
Blood Loss Anemia	1.7	1.5	1.4	1.8	2.6
Deficiency Anemia	10.3	10.4	6.5	12.1	14.8
Alcohol Abuse	1.8	1.6	2.5	1.8	1.7
Drug Abuse	0.9	0.8	1.1	0.8	1.5
Psychoses	2.2	1.7	1.5	2.4	5.6
Depression	7.7	7.0	6.4	9.6	11.4
Elixhauser Comorbidity Index
Mean	4.7	4.6	4.1	5.4	5.8
Standard Deviation	2.75	2.65	2.44	2.75	3.21
PAD Risk Factors, %
Diabetes	53.5	53.6	41.1	76.3	55.1
Chronic Hypertension	67.0	67.8	65.2	66.2	67.2
Chronic Renal Insufficiency	22.8	22.4	14.9	30.3	31.4
Smoker	12.3	12.1	18.5	6.9	7.4
Advanced Age (≥65)	58.0	60.3	52.1	49.5	63.8
Aortocoronary Bypass Status	6.1	6.5	6.2	4.9	5.0
History of Stroke	5.3	5.1	4.5	4.2	8.5

^a Conservative therapy—no revascularization or minor amputation in patients with CLI and gangrene

CLI, critical limb ischemia; PAD, peripheral artery disease; PVI, endovascular revascularization; PVS, surgical revascularization; MinAMP, minor amputation without a record of revascularization.

Figure 2. Hazard ratios by cohort. Hazard ratios for the composite endpoint of inpatient death or major amputation were estimated for each cohort using the conservative therapy cohort as the reference. MinAMP, Minor amputation without a record of PVI or PVS; PAD, peripheral artery disease; PVI, Peripheral vascular interventions; PVS, Peripheral vascular surgery.

Figure 3. Hazard ratios by intervention. Hazard ratios for the composite end-point of inpatient death or major amputation were estimated for each intervention. MinAMP, Minor Amputation without a record of PVI or PVS; PAD, peripheral artery disease; PVI, Peripheral vascular interventions; PVS, Peripheral vascular surgery.

Figure 4. Discharge status after amputation.

Figure 5. Expenditure results. Total expenditure estimates (per month). Amp, Amputation.