Interventional procedure overview of bioresorbable stent implantation to treat coronary artery disease

Device and procedure success

In an RCT of 150 patients with STEMI, there was no statistically significant difference in device success between a magnesium-based SES BRS (n=74) and a metallic SES (n=76; 99% compared with 100%, difference 1.4%, 95% CI -1.3 to 4.0, p=0.493). There was also no statistically significant difference in procedural success (96% compared with 96%, difference 0.2%, 95% CI -6.2 to 6.4, p=1.000). Device success was defined as successful implantation with less than 30% residual stenosis of the target lesion and thrombolysis in MI [TIMI] flow grade 2 or more. Procedural success was defined as device success and no in-hospital cardiac events (Sabaté 2019).

In an ASORB UK registry of 1,005 patients with new coronary lesions who had BRS, there was device success in 99% and procedure success in 97% of patients. Device success was defined as successful implantation of 1 or more scaffolds with a final in-scaffold diameter stenosis of less than 50%, without BRS device deficiency. Procedure success was defined as successful implantation of 1 or more scaffold with a final in-scaffold diameter stenosis of less than 50%, without TVF within 3 days of the index procedure (Baumbach 2018).

In an ISAR-ABSORB registry of 419 patients who had BRS, there was procedure success in 97% of patients. Procedure success was defined as residual stenosis of less than 30% and thrombolysis in MI [TIMI] grade 3 flow (Wiebe 2021).

MACE and POCE rates

In an HTA of BRS for treating CAD, a meta-analysis of 4 RCTs including 3,200 patients and with a maximum 5-year follow up found statistically significant higher rates of MACE with Absorb BRS (n=1,962) compared with permanent metal DES (n=1,238; RR 1.36, 95% CI 1.06 to 1.73, p=0.01; 0% heterogeneity). MACE comprised cardiac death, all MI and ischaemic-driven TLR. In the same study, a meta-analysis of 5 RCTs including 5,449 patients and with 5-year maximum follow up found statistically significant higher rates of POCE with Absorb BRS (n=3,153) compared with permanent metal DES (n=2,296; RR 1.36, 95% CI 1.06 to 1.73, p=0.01; 0% heterogeneity). POCE comprised of all death, all MI and all revascularisations (IAMEV 2019).

In an individual patient data meta-analysis of 4 RCTs, including 3,384 patients with CHD and with at least a 5-year follow up, reported that POCE rate was higher with BRS (n=2,161) than with EES but not statistically significantly so (n=1,223; 26% compared with 23%, HR 1.15, 95% CI 0.99 to 1.33, p=0.07). POCE comprised of all-cause mortality, all MI or all revascularisations. The increased risk of POCE with BRS compared with EES between 0 to 3 years (20% compared with 16%, HR 1.23, 95% CI 1.04 to 1.46) was not evident between 3 to 5 years (9% compared with 9%, HR 0.97, 95% CI 0.76 to 1.24, p=0.10; Stone 2019).

In the ABSORB UK registry of 1,005 patients, MACE rate was less than 1% in hospital, 1% (12/992) at 30-day follow up and 3% (34/992) with BRS at 1-year follow up. MACE rate was defined as cardiac death, all MI and ischaemia-driven TLR (Baumbach 2018).

In the ISAR-ABSORB registry of 419 patients, the 5 year rate of composite endpoint of death, MI and ischemia-driven TLR with BRS was 33% (Wiebe 2021).

In the RCT of 150 patients with STEMI, after 1 year, the POCE was higher, but not statistically significantly so, with magnesium-based SES BRS than with metallic SES (23% [17/74] compared with 15% [11/76], difference 8.5%, 95% CI -20.9 to 3.9, p=0.182), POCE comprised of all-cause death, any recurrent MI, or any revascularisation (Sabaté 2019).

TLF

In a meta-analysis of 10 studies (n=6,383), TLF was statistically significantly higher with BRS (n=3,573 than with DES group (n=2,810; OR 1.46, 95% CI 1.20 to 1.79, p=0.0002; I²=0%; Ni 2020).

In the individual patient data meta-analysis of 4 RCTs, TLF rate was statistically significantly higher with BRS than with EES (15% compared with 12%, HR 1.26, 95% CI 1.03 to 1.54, p=0.03). TFL rate was defined as the composite of cardiac death, target vessel MI and ischaemia-driven TLR. At 0- to 3-years follow up, TLF occurred in 12% of patients with BRS and 8% with EES group (HR 1.42, 95% CI 1.12 to 1.80). At 3- to 5-year follow up, TLF occurred in 4% with BRS group and 5% (with EES (HR 0.92, 95% CI 0.64 to 1.31, p=0.046; Stone 2019).

In a meta-analysis of 91 RCTs, pairwise meta-analysis of 6 RCTs in patients with stable or unstable angina (4 studies), STEMI (1 study) or with all types of CHD (1 study) showed that TLF rates were not statistically significantly different between BRS (n=3,179) and CoCr EES (n=2,239) at 1 year (OR 1.26, 95% CI 0.99 to 1.61, p=0.059, I²=0%). However, they were statistically significantly higher with BRS than CoCr EES at follow up of over than 1 year (OR 1.39, 95% CI 1.15 to 1.67, p<0.001, I²=0%; Kang 2018).

In the ABSORB UK registry of 1,005 patients, TLF rate was less than 1% in hospital, 1% at 30 days and 3% at 1 year. TLF rate was defined as the composite of cardiac death, target vessel MI and ischaemia-driven TLR (Baumbach 2018).

In a case series of 184 patients with new lesions and stable or unstable angina or documented silent ischemia, TLF occurred in 6% of patients at 2 years after resorption of a magnesium-based SES BRS and in 6% at 3 years (Haude 2020).

TVF

In the ABSORB UK registry of 1,005 patients, TVF (including cardiac death, all MI and ischaemia-driven TVR) was reported in 1% of patients at 30 days and 4% (at 1-year follow-up (Baumbach 2018).

TLR/TVR

In the HTA of BRS for treating CAD, a meta-analysis of 8 RCTs including 5,827 patients at maximum follow-up found a statistically significant higher rate of TLR with Absorb BRS (n=3,342) compared with permanent metal DES (n=2,485; RR 1.36, 95% CI 1.08 to 1.71; p=0.009; 0% heterogeneity). In a meta-analysis of 8 studies after a maximum length of follow-up, the rate of TVR was significantly higher in the Absorb BRS group than in the DES group [RR 1.18 (95% CI 0.98–1.41); p=0.08; I²=0% heterogeneity] (IAMEV 2019).

In the meta-analysis of 91 RCTs, pairwise meta-analysis of 6 RCTs comparing BRS and CoCr EES found that there was no statistically significant difference in TLR at 1 year between the groups (OR 1.28, 95% CI 0.91 to 1.80, p=0.150). However, there was a statistically significant difference at follow up of over a 1 year (OR 1.46, 95% CI 1.12 to 1.85, p=0.004). A network meta-analysis of 91 RCTs showed similar performance with BRS and other DES, and statistically significantly better than BMS in terms of TVR and TLR (Kang 2018).

In the individual patient data meta-analysis of 4 RCTs, there were statistically significantly increased rates of ischemia-driven TLR (8% with BRS compared with 6% with EES, HR 1.41, 95% CI 1.06 to 1.87, p=0.02) and ischemia driven TVR (13% compared with 20%, HR 1.32, 95% CI 1.06 to 1.65, p=0.01). Between 3 and 5 years, the rates were not statistically significantly different between the groups (Stone 2019).

In the ABSORB UK registry of 1,005 patients, TLR was 1% at 30 days and 3% (with BRS at 1-year follow up. TVR rate was 1% at 30 days and 4% at 1-year follow up. All coronary revascularisation rate (based on the ARC definition) at 1 year was 14% (Baumbach 2018).

In the ISAR-ABSORB registry of 419 patients, the incidence of TLR with BRS at 12 months was 10% and increased to 20% between 1 and 5 years (Wiebe 2021).

In the RCT of 150 patients with STEMI, ischaemia-driven TLR at 1 year was statically significantly higher with magnesium-based SES BRS compared with metallic SES (16% [12/74] compared with 5% [4/76], difference 11%, 95% CI -20.7 to -1.2, p=0.030). TVR at 1 year was also higher with magnesium-based SES BRS compared with metallic SES (20% [15/74] compared with 8% [6/76], difference 13%, 95% CI -23.4 to -1.4, p=0.029; Sabaté 2019).

In the case series of 184 patients, clinically driven TLR was reported in 3% (6/174) of patients and clinically driven TVR in 5% (9/174) of patients at 3-year follow up with magnesium-based SES BRS (Haude 2020).

Reduced need for long-term anticlotting medicines

In the case series of 184 patients, 53% of patients were on dual antiplatelet therapy at 12 months, 19% at 2 years and 16% at 3 years with magnesium-based SES BRS (Haude 2020).

Angina status

In the case series of 184 patients, angina status in all patients (either stable or unstable angina, or documented silent ischemia) improved from baseline to follow up with magnesium-based SES BRS. In all, 93% of patients were symptom-free 2 years after scaffold resorption and 92% were symptom free at 3 years (Haude 2020).