Long-term outcomes in the smoking claudicant after peripheral vascular interventions

OBJECTIVE

Emphasis on tobacco cessation, given the urgent and emergent nature of vascular surgery, is less prevalent than standard elective cases such as hernia repairs, cosmetic surgery, and bariatric procedures. The goal of this study is to determine the effect of active smoking on claudicating individuals undergoing peripheral vascular interventions (PVIs). Our goal is to determine if a greater emphasis on education should be placed on smoking cessation in nonurgent cases scheduled through clinic visits and not the Emergency Department.

METHODS

This study was performed using the multi-institution de-identified Vascular Quality Initiative/Medicare-linked database (Vascular Implant Surveillance and Interventional Outcomes Network [VISION]). Claudicants who underwent PVI for peripheral arterial occlusive disease between 2004 and 2019 were included in our study. Our final sample consisted of a total of 18,726 patients: 3617 nonsmokers (19.3%) (NSs), 9975 former smokers (53.3%) (FSs), and 5134 current smokers (27.4%) (CSs). We performed propensity score matching on 29 variables (age, gender, race, ethnicity, treatment setting [outpatient or inpatient], obesity, insurance, hypertension, diabetes, coronary artery disease, congestive heart failure, chronic obstructive pulmonary disease, chronic kidney disease, previous coronary artery bypass graft, carotid endarterectomy, major amputation, inflow treatment, prior bypass or PVI, preoperative medications, level of treatment, concomitant endarterectomy, and treatment type [atherectomy, angioplasty, stent]) between NS vs FS and FS vs CS. Outcomes were long-term (5-year) overall survival (OS), limb salvage (LS), freedom from reintervention (FR), and amputation-free survival (AFS).

RESULTS

Propensity score matching resulted in 3160 well-matched pairs of NS and FS and 3750 well-matched pairs of FS and CS. There was no difference between FS and NS in terms of OS (hazard ratio [HR], 0.94; 95% confidence interval [CI], 0.82-1.09; P = .43), FR (HR, 0.96; 95% CI, 0.89-1.04; P = .35), or AFS (HR, 0.90; 95% CI, 0.79-1.03; P = .12). However, when compared with CS, we found FS to have a higher OS (HR, 1.18; 95% CI, 1.04-1.33; P = .01), less FR (HR, 0.89; 95% CI, 0.83-0.96; P = .003), and greater AFS (HR, 1.16; 95% CI, 1.03-1.31; P = .01).

CONCLUSIONS

This multi-institutional Medicare-linked study looking at elective PVI cases in patients with peripheral artery disease presenting with claudication found that FSs have similar 5-year outcomes in comparison to NSs in terms of OS, FR, and AFS. Additionally, CSs have lower OS and AFS when compared with FSs. Overall, this suggests that smoking claudicants should be highly encouraged and referred to structured smoking cessation programs or even required to stop smoking prior to elective PVI due to the perceived 5-year benefit.

Joint moment strategies during stair descent in patients with peripheral arterial disease and intermittent claudication

OBJECTIVE

To determine the lower limb joint kinetic strategies during stair descent in claudicants with peripheral arterial disease (PAD-IC).

DESIGN

Cross-sectional observation study.

SETTING

University laboratory.

PARTICIPANTS

A total of 22 participants; 10 healthy controls and 12 patients diagnosed with PAD-IC.

MAIN OUTCOME MEASURES

Between-group comparisons of ground reaction force (GRF) and, hip, knee and ankle kinetics during steady-state stair descent.

RESULTS

The claudicating-limb group demonstrated reduced vertical and posterior GRF compared to healthy controls (ES = -1.46 [-2.32,-0.69] and ES = -1.08 [-0.42,-0.26]) as well as demonstrating an greater contribution to support moment from the ankle and trends towards a smaller hip contribution (42 ± 14% vs 28 ± 7%, P = .005 and Hip 16 ± 8% vs 21 ± 11%, P = .056, respectively). A unique sub-group was identified within the PAD-IC cohort demonstrating different hip moment strategies during weight acceptance: a novel hip extensor group (PAD-IC HExt) and stereotypical hip flexor group (PAD-IC HFlex). Compared to both healthy controls and the PAD-IC HFlex groups, the PAD-IC HExt group demonstrated increased hip extensor moment (ES = 3.05 [1.67,4.42] and ES = 3.62 [1.89,5.35]) and reduced knee extensor moment (ES = -2.00 [-3.15,-0.85] and ES = -1.36 [-2.60,-0.11] respectively) during weight acceptance.

CONCLUSIONS

A novel hip extensor strategy was identified in a sub-group of claudicants which acts to reduce the demand on the knee extensors, but not the plantarflexors. Weakness in the knee extensors may prevent redistribution of the task demand, typically seen in older adults in stair descent, away from the functionally limited plantarflexor muscle group. Further investigation into multi-level joint strength and the relationship to functional tasks is warranted to inform targeted intervention programmes.

Sagittal plane joint kinetics during stair ascent in patients with peripheral arterial disease and intermittent claudication

Stair negotiation poses a substantial physical demand on the musculoskeletal system and this challenging task can place individuals at risk of falls. Peripheral arterial disease (PAD) can cause intermittent claudication (IC) pain in the calf and results in altered gait mechanics during level walking. However, whether those with PAD-IC adopt alternate strategies to climb stairs is unknown. Twelve participants with PAD-IC (six bilateral and six unilateral) and 10 healthy controls were recruited and instructed to ascend a five-step staircase whilst 3D kinematic data of the lower-limbs were recorded synchronously with kinetic data from force plates embedded into the staircase on steps two and three. Limbs from the unilateral group and both limbs from the bilateral claudicants were categorised as claudicating (N=18), asymptomatic (N=6) and control (N=10). Claudicants walked more slowly than healthy controls (trend; P=<0.066). Both claudicating- and asymptomatic-limb groups had reduced propulsive GRF (P=0.025 and P=0.002, respectively) and vertical GRF (P=0.005 and P=0.001, respectively) compared to controls. The claudicating-limb group had a reduced knee extensor moment during forward continuance (P=0.060), ankle angular velocity at peak moment (P=0.039) and ankle power generation (P=0.055) compared to the controls. The slower gait speed, irrespective of laterality of symptoms, indicates functional capacity was determined by the limitations of the claudicating limb. Reduced ankle power generation and angular velocity (despite adequate plantarflexor moment) implies velocity-dependent limitations existed in the calf. The lack of notable compensatory strategies indicates reliance on an impaired muscle group to accomplish this potentially hazardous task, highlighting the importance of maintaining plantarflexor strength and power in those with PAD-IC.