Daily Cardiology Research Analysis
Three rigorously conducted multicenter trials stand out today. A Lancet randomized trial shows that intensive LDL-C lowering with evolocumab does not reduce 24‑month saphenous vein graft disease after CABG, challenging assumptions about early graft failure biology. A phase 3 RCT demonstrates potent LDL-C reduction with the new anti-PCSK9 antibody recaticimab in heterozygous familial hypercholesterolemia, and a multicenter RCT supports non/minimized‑fluoroscopy AF ablation as noninferior while dr
Summary
Three rigorously conducted multicenter trials stand out today. A Lancet randomized trial shows that intensive LDL-C lowering with evolocumab does not reduce 24‑month saphenous vein graft disease after CABG, challenging assumptions about early graft failure biology. A phase 3 RCT demonstrates potent LDL-C reduction with the new anti-PCSK9 antibody recaticimab in heterozygous familial hypercholesterolemia, and a multicenter RCT supports non/minimized‑fluoroscopy AF ablation as noninferior while dramatically cutting radiation exposure.
Research Themes
- Re-evaluating mechanisms of early saphenous vein graft failure after CABG
- Next-generation PCSK9 inhibition for genetic dyslipidemia
- Radiation-sparing strategies in electrophysiology without loss of efficacy
Selected Articles
1. Effect of evolocumab on saphenous vein graft patency after coronary artery bypass surgery (NEWTON-CABG CardioLink-5): an international, randomised, double-blind, placebo-controlled trial.
In a double-blind multicenter RCT of 782 post-CABG patients, evolocumab achieved ~48% greater LDL-C reduction than placebo but did not reduce 24‑month saphenous vein graft disease (21.7% vs 19.7%; p=0.44). Safety profiles were similar, suggesting early SVG failure mechanisms are not substantially modified by further LDL-C lowering.
Impact: This definitive negative RCT challenges the assumption that intensive LDL lowering mitigates early SVG failure, redirecting research toward non–LDL-driven mechanisms and informing postoperative therapy priorities.
Clinical Implications: Routine PCSK9 intensification solely to prevent early SVG disease after CABG is not supported; focus should remain on guideline-directed lipid therapy for global ASCVD risk and optimization of surgical/conduit factors.
Key Findings
- Evolocumab achieved a 48.4% placebo-adjusted LDL-C reduction at 24 months (−52.4% vs −4.0%).
- Primary endpoint: 24‑month vein graft disease rate was 21.7% with evolocumab vs 19.7% with placebo (difference 2.0%, 95% CI −3.1 to 7.1; p=0.44).
- Adverse events were similar between groups, indicating acceptable safety.
- Findings suggest non–LDL-dependent contributors dominate early SVG failure.
Methodological Strengths
- International, randomized, double-blind, placebo-controlled design with ClinicalTrials.gov registration.
- Objective imaging-based primary endpoint with standardized assessment.
Limitations
- Primary outcome is surrogate (SVG ≥50% stenosis) rather than clinical events.
- Modified ITT with incomplete imaging follow-up may introduce attrition bias.
Future Directions: Investigate non–LDL-mediated pathways of early SVG failure (e.g., thrombosis, inflammation, graft handling/flow dynamics) and evaluate targeted preventive strategies.
BACKGROUND: Saphenous vein graft (SVG) failure remains a substantial challenge after coronary artery bypass graft (CABG). LDL cholesterol (LDL-C) is a causal risk factor for atherosclerosis, but its role in SVG failure is not well established. We evaluated whether early initiation of intensive LDL-C lowering with evolocumab could reduce SVG failure. METHODS: NEWTON-CABG CardioLink-5 was a multicentre, double-blind, randomised, placebo-controlled trial conducted at 23 sites in Canada, the USA, Australia, and Hungary. Eligible participants were adults (age ≥18 years) who underwent CABG with at least two SVGs and were being treated with statin therapy of moderate or high intensity. Participants were randomly allocated (1:1; variable block size) within 21 days of CABG to subcutaneous evolocumab 140 mg or placebo every 2 weeks. The primary endpoint was the 24-month vein graft disease rate (VGDR; the proportion of SVGs with ≥50% occlusion on coronary CT angiography or clinically indicated invasive angiography) in the modified intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT03900026, and is completed. FINDINGS: Between June 17, 2019, and Nov 10, 2022, 782 individuals were randomly assigned (389 to evolocumab and 393 to placebo). At baseline, among the 554 participants with primary outcome data available, the median age was 66 years (IQR 60-72), 471 (85%) of 554 participants were male and 83 (15%) were female, and the median LDL-C was 1·85 mmol/L (IQR 1·25-2·84) in the evolocumab group and 1·86 mmol/L (1·20-2·76) in the placebo group. Evolocumab resulted in a mean 48·4% placebo-adjusted reduction in LDL-C at 24 months (-52·4% vs -4·0%). The 24-month VGDR was 21·7% (149 of 686 grafts) in the evolocumab group and 19·7% (127 of 644 grafts) in the placebo group (difference 2·0% [95% CI -3·1 to 7·1]; p=0·44). Treatment was well tolerated, with similar adverse event profiles between the groups. INTERPRETATION: Among patients who underwent CABG, evolocumab did not reduce SVG disease at 24 months following the index surgery despite substantial LDL-C lowering. Further LDL-C lowering does not appear to meaningfully affect the pathophysiological mechanisms responsible for early SVG failure. FUNDING: Amgen Canada.
2. Recaticimab in adult heterozygous familial hypercholesterolaemia (REMAIN-3): a multicentre, randomized, double-blind, placebo-controlled Phase 3 study.
In a phase 3, double-blind RCT of 143 HeFH patients on background lipid therapy, recaticimab reduced LDL-C by 54.4% at 12 weeks versus 4.5% with placebo (difference −49.8%; P<0.0001) and improved non‑HDL‑C, ApoB, and Lp(a). Safety was acceptable with similar overall TRAEs, though more injection site reactions occurred.
Impact: Introduces a new anti-PCSK9 biologic with robust LDL-C lowering in HeFH, expanding therapeutic options and supporting competition and access, especially in regions with limited PCSK9 availability.
Clinical Implications: Recaticimab may be considered for HeFH patients inadequately controlled on standard lipid-lowering therapy, pending longer-term outcomes and head‑to‑head comparisons with established PCSK9 inhibitors.
Key Findings
- Primary endpoint: LDL-C change at 12 weeks −54.4% with recaticimab vs −4.5% with placebo; treatment difference −49.8% (95% CI −55.8 to −43.9; P<0.0001).
- Favorable effects on non‑HDL‑C, ApoB, and Lp(a) versus placebo.
- TRAEs similar between groups (27.4% vs 25.0%); higher injection site reactions with recaticimab (8.4% vs 0%).
Methodological Strengths
- Randomized, double-blind, placebo-controlled phase 3 design across 25 sites with trial registration.
- Prespecified primary endpoint with tight confidence intervals and consistent secondary lipid outcomes.
Limitations
- Short duration (12 weeks) without clinical outcomes.
- Single-country cohort (China) may limit global generalizability; no head-to-head comparison with established PCSK9 inhibitors.
Future Directions: Evaluate long-term efficacy, safety, immunogenicity, dosing intervals, and cardiovascular outcomes; perform head‑to‑head trials versus approved PCSK9 inhibitors.
AIMS: Heterozygous familial hypercholesterolaemia (HeFH) is a genetic disorder, characterized by high plasma concentrations of low-density lipoprotein cholesterol (LDL-C) from birth. This study aimed to assess the efficacy and safety of recaticimab, a new humanized anti-PCSK9 antibody capable of reducing LDL-C levels in patients with poorly controlled HeFH. METHODS AND RESULTS: REMAIN-3 was a multicentre, randomized, double-blind, placebo-controlled Phase 3 study done at 25 sites in China. Patients with a genetic or clinical diagnosis of HeFH, who were on stable lipid-lowering therapy for ≥28 days, had fasting LDL-C ≥ 2.6 mmol/L (or ≥1.8 mmol/L for those with a history of atherosclerotic cardiovascular disease), and had fasting triglyceride ≤5.6 mmol/L, were randomly allocated in a 2:1 ratio to receive subcutaneous recaticimab at 150 mg or matching placebo every 4 weeks for 12 weeks. The primary endpoint was the percentage change in LDL-C from baseline to Week 12. Overall, 143 patients underwent randomization and received recaticimab (n = 95) or placebo (n = 48). At Week 12, the mean percentage change in LDL-C from baseline was -54.4% (95% CI, -57.9 to -50.8%) in the recaticimab group and -4.5% (95% CI, -9.4 to 0.3%) in the placebo group, with a treatment difference of -49.8% (95% CI, -55.8 to -43.9%; P < 0.0001). Recaticimab was superior to placebo in improving other lipid variables, including non-high-density lipoprotein cholesterol, apolipoprotein B, and lipoprotein a. Treatment-related adverse events (TRAEs) were comparable between groups (27.4% with recaticimab vs. 25.0% with placebo). The most common TRAEs occurring more frequently with recaticimab than placebo were injection site reaction (8.4% vs. 0%) and increased blood creatine phosphokinase (5.3% vs. 2.1%). CONCLUSION: Recaticimab significantly lowered the LDL-C level compared with placebo, with an acceptable safety profile, providing a new effective treatment option for patients with inadequately controlled HeFH. REGISTRATION: ClinicalTrials.gov Identifier: NCT04844125.
3. Multicenter Practice of Non/Minimized Fluoroscopy Ablation for Paroxysmal AF in China: The PAF-ICE Trial.
In a 15-center RCT (n=448) of paroxysmal AF, ICE-guided non/minimized‑fluoroscopy ablation was noninferior to traditional fluoroscopy guidance for arrhythmia‑free survival at a median 12.2 months (82.5% vs 84.0%; HR 0.949; P=0.858) with no safety differences. More than half of patients underwent radiation‑free procedures, substantially reducing exposure.
Impact: Provides high-level evidence that zero/near‑zero fluoroscopy AF ablation maintains efficacy and safety, supporting radiation‑sparing procedural standards with potential benefits for patients and staff.
Clinical Implications: Centers can adopt ICE‑guided, radiation‑sparing workflows for paroxysmal AF ablation without compromising outcomes, reducing cumulative x‑ray exposure and ergonomic burdens from lead protection.
Key Findings
- Primary efficacy: arrhythmia‑free survival 82.5% (non/minimized fluoroscopy) vs 84.0% (traditional); HR 0.949 (95% CI 0.774–1.164), P=0.858 (noninferior).
- Primary safety composite did not differ between groups (P=0.975).
- Radiation-free procedures in 56.1% and near‑zero radiation (<1 mGy mean) achieved in 46.7% of centers; marked reduction in x‑ray use and protective equipment needs.
Methodological Strengths
- Prospective multicenter randomized design with clearly defined efficacy and safety endpoints.
- Real-world procedural implementation across 15 centers enhances external validity.
Limitations
- Follow-up of median ~12 months limits long-term durability assessment.
- Nonblinded operators; endpoints focused on recurrence rather than broader quality-of-life measures.
Future Directions: Assess long-term arrhythmia control, radiation metrics in diverse settings, training curves for zero‑fluoro workflows, and integration with advanced mapping technologies.
BACKGROUND: Intracardiac echocardiography (ICE)-guided non/minimized-fluoroscopy catheter ablation for atrial fibrillation (AF) has been reported, but its effectiveness and safety still lack multicenter evidence. OBJECTIVES: The authors sought to evaluate the effectiveness and safety of ICE-guided non/minimized-fluoroscopy catheter ablation compared with the traditional fluoroscopy-guided approach in patients with paroxysmal AF. METHODS: A total of 448 patients with paroxysmal AF, from 15 centers in China, were randomly assigned in a 1:1 ratio to a non/minimized-fluoroscopy group (n = 223) and a traditional approach group (n = 225). The primary efficacy endpoint was freedom from AF recurrence after a single ablation procedure. The primary safety endpoint was a composite of death from any cause, stroke or transient ischemic attack, and other serious adverse events. RESULTS: Pulmonary vein isolation was achieved in all patients. After a median follow-up of 12.2 (Q1-Q3: 8.8-17.7) months, 184 of 223 patients (82.5%) in the non/minimized-fluoroscopy group and 189 of 225 (84.0%) in the traditional approach group remained free from arrhythmia. Cox analysis showed a HR of 0.949 (95% CI: 0.774 to 1.164); P = 0.858, demonstrating the noninferiority of the non/minimized-fluoroscopy approach. The primary safety endpoint did not differ significantly in the 2 groups (P = 0.975). This protocol enabled near zero-radiation procedures (mean <1 mGy) in 7 of 15 centers (46.7%), and radiation-free AF ablation in 125 of 223 patients (56.1%), significantly reducing x-ray exposure and operator radiation protection equipment usage. CONCLUSIONS: ICE-combined non/minimized-fluoroscopy AF ablation was noninferior in effectiveness compared to traditional AF ablation, with no significant difference in safety endpoints, indicating its potential of widespread adoption.