XXS trial to compare primary angioplasty with stenting in arteries below the knee

Gunnar Tepe
Gunnar Tepe

Gunnar Tepe (head of Diagnostic and Interventional Radiology, Academic Hospital RoMed, Clinic of Rosenheim, Germany) presented an update on the status of the XXS trial at the VEITHsymposium (19–23 November, New York, USA).

“In this first randomised study comparing primary stent vs. angioplasty application in critical limb ischaemia patients, we could include 105 of the 176 patients enrolled in the intention-to-treat analysis and observed a 100% interventional success rate in the Xpert stent (Abbott) group,” Tepe noted.

He told delegates that 176 patients who were enrolled in 11 active centres in Germany and Austria were randomised to receive either angioplasty (88) or stenting (88). “Of these, 71 were excluded for the final analysis because they did not meet the criteria of the intention to treat (one of the following: 12-month follow-up including the primary endpoint; target lesion revascularisation; death; myocardial infarction; major amputation or, performance of 12-month follow-up angiography). This left 47 patients in the angioplasty group and 58 in the Xpert stent group. Almost 25% (n=11) of the patients in the angioplasty group needed a bailout stent procedure due to dissection, calcification or recoil, leaving the final numbers at 37 being treated by angioplasty alone and 69 in the stent group,” Tepe stated.

Inclusion was based on patients presenting with Rutherford category four and five lesions; the inflow vessels being successfully treated before randomisation; a maximum treated length below the knee of up to 15cm (which could be divided in up to three segments); a maximum of two treated vessels and a minimum distance of the target lesion to the talus of 5cm.

The researchers excluded patients if there was acute thrombus present, a previously implanted stent present, if they were not able to cross the lesion below the knee or the index vessel did not have a run-off to the foot.

The primary endpoint is the per cent diameter stenosis of the target lesion assessed by angiography at one year compared to the angiographic assessment at baseline. The assessment is to be carried out by an independent core lab, Tepe stated.

Patients included in the trial were around 75 years old and over 70% of the cohort was male. A high proportion of patients were diabetics; and a majority suffered from hypertension.

At baseline, in the angioplasty group, 23% of 87 patients had Rutherford category four lesions and had ischaemic rest pain. Seventy seven per cent of 87 patients had Rutherford category five lesions and had ischaemic tissue loss. In the stent group, 14.9% of 87 patients had Rutherford category four lesions with ischaemic rest pain and 85.1% had category five lesions with the concomitant ischaemic tissue loss.

“Lesions in both groups were mostly de novo in origin. There was none or mild calcification in 54.9% (51 patients) in the angioplasty group and 50% (54 patients) in the stent group. Just over 45% (51) had moderate or severe calcification in the angioplasty group and 50% (54) had this type of calcification in the stent group. There were between 30–40% chronic total occlusions in both groups. The lesion length of the study lesion was 8±5.7cm in the angioplasty group and 6.6±4.2cm in the patients who received stents (p=0.101). The per cent stenosis was 83.1± 8.1 (83) in the angioplasty group and 79±20.3 (83) in the group that was stented (p=0.171), Tepe said. Longer term data, such as the one-year data are still awaited, he reported.