Surgery · Medical Literature
Sirolimus-Coated Balloon Angioplasty for Infrainguinal Artery Disease
Abstract
New England Journal of Medicine, Ahead of Print.
Clinical relevance
In patients with symptomatic infrainguinal artery disease undergoing endovascular treatment, does angioplasty with a sirolimus-coated balloon reduce the incidence of major adverse limb events compared with standard uncoated balloon angioplasty at one year? __SNAPSHOT__ {"studyDesign":"Prospective, open-label, randomized controlled noninferiority trial with prespecified sequential testing for superiority and blinded outcome adjudication (SirPAD trial)","setting":"44 vascular care centers in Switzerland; procedures performed at two trial sites by 15 operators; enrollment November 2020 through December 2024","sampleSize":"n=1,252 (sirolimus-coated balloon: n=626; uncoated balloon: n=626)","population":"Adult patients with symptomatic peripheral artery disease involving the femoropopliteal arteries or below-the-knee (BTK) arteries warranting endovascular intervention; mean age approximately 75 years; 35.1% women; all-comers design including patients with critical limb ischemia (CLI) typically excluded from device trials","intervention":"MagicTouch PTA sirolimus-coated balloon (Concept Medical)","comparator":"Any approved uncoated (plain) balloon angioplasty","primaryOutcome":"Composite of unplanned major amputation of the target limb OR endovascular/surgical revascularization of the target lesion for critical limb ischemia within 1 year after randomization (major adverse limb events, MALE)","followUp":"1 year","fundingSource":"Industry (unrestricted grant from Concept Medical, manufacturer of the MagicTouch PTA sirolimus-coated balloon) and institutional (University Hospital Zurich and University of Zurich); investigator-initiated trial"}
Key findings
At 1 year, the primary composite endpoint (MALE: unplanned major target-limb amputation or target lesion revascularization for CLI) occurred in 55 patients (8.8%) in the sirolimus-coated balloon group versus 94 patients (15.0%) in the uncoated balloon group. The median unbiased estimate of risk difference was −4.9 percentage points (95% CI, −8.5 to −1.3; p<0.001 for noninferiority; p=0.009 for superiority). NNT to prevent one primary endpoint event at 1 year = approximately 16 (calculated: 1/0.062 ≈ 16). The trial thereby met both noninferiority and superiority thresholds sequentially as prespecified. For the key secondary outcome (composite of any unplanned amputation or any target lesion revascularization for critical or noncritical limb ischemia), events occurred in 144 patients (23.0%) in the sirolimus-coated balloon group versus 193 patients (30.8%) in the uncoated balloon group (absolute risk difference, −7.8 percentage points; 95% CI, −12.7 to −2.9; p=0.002 for superiority). All-cause mortality at 1 year was 11.8% (74/626) in the sirolimus-coated balloon group versus 12.8% (80/626) in the uncoated balloon group (risk difference, −1.0 percentage points; 95% CI, −4.6 to 2.7; p=0.67), indicating no significant difference in mortality. Authors noted that the reduction in the primary outcome was driven by concordant effects across both individual components of the composite endpoint. Specific adverse event rates beyond all-cause mortality are not reported in the abstract.
Practice implications
⚠ Only the abstract is available; full methodology, subgroup analyses, per-protocol analyses, baseline characteristic balance, and detailed safety data cannot be independently verified from this summary. The SirPAD trial establishes that sirolimus-coated balloon angioplasty is both noninferior and superior to uncoated balloon angioplasty for the prevention of MALE at 1 year in an all-comers population with symptomatic infrainguinal PAD, including patients with CLI and BTK disease—groups historically underrepresented in device trials. The absolute risk reduction of approximately 6 percentage points in MALE (NNT ≈ 16, calculated) is clinically meaningful given the severity of these endpoints (amputation and CLI-driven revascularization). Mortality was similar between groups, which is reassuring from a safety standpoint and avoids the signal that complicated early paclitaxel-coated balloon data. The benefit in BTK disease is particularly notable, as paclitaxel-coated balloons have not demonstrated efficacy in this anatomic territory. However, generalizability is tempered by the single-country (Switzerland), two-center procedural design and the 1-year follow-up, which does not capture late restenosis, delayed safety signals, or durability of limb salvage. Industry funding from the device manufacturer (Concept Medical) warrants scrutiny of effect size estimates, though the investigator-initiated, blinded-adjudication design partially mitigates this concern. Whether findings apply uniformly across lesion complexity (TASC classifications not reported in abstract), diabetic subpopulations, and racially/ethnically diverse populations requires further study. __LIMITATIONS__ Open-label design introduces potential performance bias, though outcome adjudication was blinded.,Single-country (Switzerland), two-center procedural design conducted by only 15 operators limits generalizability to broader international practice and diverse healthcare systems.,Follow-up limited to 1 year; long-term durability of limb salvage and late safety signals (e.g., delayed restenosis, drug toxicity) remain unknown.,Industry funding from Concept Medical (device manufacturer), despite investigator initiation and blinded adjudication, represents a potential conflict of interest.,Composite primary endpoint may obscure differential effects on its components (amputation vs. revascularization); full decomposition not available from abstract alone.,Specific lesion-level characteristics (e.g., lesion length, TASC class, calcification burden), comorbidity detail, and antiplatelet/anticoagulation protocols are not reported in the abstract.,The noninferiority margin of 5% was prespecified for safety but the clinical justification for this threshold cannot be evaluated from the abstract.,Patient demographics (mean age ~75, 35.1% women, Swiss population) may not be representative of younger, more diverse, or higher-risk global PAD populations.,Comparison was against 'any approved uncoated balloon,' introducing heterogeneity in the control arm (balloon type, sizing, inflation protocol). __BOTTOM_LINE_CATEGORY__ potentially_practice_informing __BOTTOM_LINE__ The SirPAD trial demonstrates that sirolimus-coated balloon angioplasty (MagicTouch PTA) is both noninferior and superior to uncoated balloon angioplasty for preventing major adverse limb events at 1 year in patients with symptomatic infrainguinal PAD, including those with CLI and below-the-knee disease, with an NNT of approximately 16 (calculated) and no mortality penalty. These results are clinically meaningful and position sirolimus-coated balloons as a compelling evidence-based upgrade to plain balloon angioplasty in this setting, though confirmation of long-term durability, safety beyond 1 year, and generalizability to non-Swiss populations is needed before universal adoption.