FUTURE-III trial reinforces potential of thinner-strut BRS for CAD

In the FUTURE-III trial, the Firesorb bioresorbable scaffold (BRS) – a thinner-strut (100/125 µm) poly-L-lactic acid-based sirolimus-eluting BRS – exhibits promising 1-year efficacy and safety profiles in terms of target lesion failure (TLF).

“This pooled, patient-level analysis indicates that the thinner-strut BRS achieves the objective performance criterion (OPC) goal regarding [the primary endpoint of 1-year TLF] and exhibits promising efficacy and safety in patients with de novo noncomplex lesions,” said the researchers.

The primary endpoint is a composite of cardiac death, target vessel myocardial infarction (TV-MI), and ischaemia-driven target lesion revascularization (ID-TLR). [BMC Medicine 2025;23:419]

At 1 year, the cumulative incidence of TLF was 1.67 percent, with a 95 percent upper confidence interval of 2.57 percent. According to the researchers, this is significantly lower than the preset OPC goal of 6.6 percent (p<0.001) and the chosen expected rate of 4.4 percent. “Hence, the prespecified goal for China FDA was achieved.”

There were no differences across prespecified subgroups of interest, including age, gender, smoking status, and presence or absence of cardiovascular comorbidities, they said.

The rates of single TLF components were 0.42, 0.92, and 0.42 percent for cardiac death, TV-MI, and ID-TLR, respectively.

The cumulative rate of patient-oriented composite endpoint was 3.34 percent – 0.42 percent for all-cause death, 1 percent for any MI, and 2.01 percent for any revascularization.

Periprocedural MI occurred in 0.75 percent. None experienced definite or probable device thrombosis within 1 year.

First-gen devices tied to adverse outcomes

First-generation BRS have been associated with higher incidences of device-related adverse outcomes than everolimus-eluting stents, the researchers noted. “Strut thickness (>150 μm), which tends to be twice that of metallic stents, might be the most compelling explanation, leading to greater strut protrusion and turbulent flow, increased neointimal growth, and unfavourable resorption-related process.”

“Firesorb BRS … is designed to reduce lumen protrusion and improve the physiological indices of local blood flow,” they continued.

Patient-level data obtained from 1,205 patients (mean age 58 years, 73.5 percent men) in the FUTURE-II randomized controlled trial (n=215) and FUTURE-III registry (n=990) were prospectively collected, pooled, and analysed. The full analysis set comprised 1,204 patients. A total of 1,196 patients (99.3 percent) completed the 1-year follow-up.

“[The current findings suggest that thinner-strut BRS] may improve fluid dynamics and facilitate accelerated and comprehensive endothelization,” the investigators said.

However, they noted that the results are only applicable to patients with relatively stable symptoms and noncomplex coronary lesions. “Although our findings met the prespecified OPC goal, the observed event rates were lower than initially anticipated. This lower-than-expected event rate should be considered when interpreting the study results, as it might limit generalizability to all-comer populations.”

The researchers called for larger randomized trials powered to compare the thinner-strut BRS against drug-eluting stents. Longer studies may also be needed, as the 1-year follow-up is insufficient to ascertain if there are meaningful late clinical outcomes.