In a recent study of patients with intermittent claudication (IC) caused by isolated superficial femoral artery (SFA) lesions, researchers found that primary stenting conferred benefits in health-related quality of life (HRQoL) at 36 months from treatment compared with best medical therapy (BMT) alone, which were lost at the 60-month mark, where a high crossover rate affected the power of the final analysis.
Results of the study were recently published online in the European Journal of Vascular and Endovascular Surgery (EJVES). The investigators—led by Thordur Gunnarsson (Lund University, Lund, Sweden)— highlight their previous finding that primary stenting of the SFA in IC increased HRQoL after 12 and 24 months in this trial. The current paper, they note, presents an extended follow-up of HRQoL 36 and 60 months after randomisation.
This was a multicentre randomised controlled trial conducted at seven vascular clinics in Sweden between 2010 and 2020, which included 100 patients randomised to either primary stenting and BMT (n=48) or BMT alone (n=52) followed for 60 months.
Gunnarsson et al detail that HRQoL—which they assessed using the Short-Form Health Survey (SF-36) and EuroQoL 5 dimensions (EQ5D) 36 and 60 months after randomisation—was the primary outcome. Walking Impairment Questionnaire (WIQ) score, reinterventions, progression to chronic limb-threatening ischaemia (CLTI), amputation, and death were secondary outcomes.
The authors report that, at 36-month follow-up, the stent group (n=32) had “significantly better” scores in the SF- 36 domain Role Physical (RP, p=0.023) and the Physical Component Summary (PCS, p=0.032) compared to the control group (n=30), however, there was no significant difference in EQ5D scores (p=0.523).
In addition, they reveal that WIQ was also “significantly better” compared to the control group (p=0.029) at 36 months.
At 60-month follow-up, Gunnarsson and colleagues found no significant difference in HRQoL between the stent (n=31) and the control group (n=32), and that there was no difference in progression to CLTI, amputation (2.1% vs. 1.9%) or mortality (14.6% vs. 15.4%) between groups. The authors point out that crossover from control to stent group was 25% at this later follow-up point.
The authors recognise that their study has some limitations. They note, for example, that as the study was originally designed to detect differences in the primary outcome at 24 months with an expected 10% loss to follow-up, both the prolonged follow-up and additional loss of patients at 36 and 60 months and the 25% crossover from the control group to stent at 60 months “negatively affected the power of the analysis”. In future trials of invasive treatment of IC, they write, crossover and loss to follow-up “need to be taken into account”.
“We interpret the trial results in favour of stent treatment for at least 36 months for physical HRQoL measures for the [IC] patient,” Gunnarsson et al write in the discussion of their findings. While they acknowledge that the trial does not give robust evidence for a lasting effect of stenting until 60 months, it suggests instead that a “transient period” of improved HRQoL “might be valuable” for an elderly vascular patient.
They summarise the wider impact their results might have: “This trial provides information relevant when presenting treatment options for patients as well as for health authorities.”