A recent Cardiology digest,
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Study Type: Prospective invasive exercise haemodynamic study (mechanistic, single-arm, pre/post design)

Key Question: Does sotatercept improve or impair right ventricular (RV) contractile function and RV-pulmonary artery (PA) coupling in PA hypertension?

Key Findings:

• Sotatercept reduced PA elastance (afterload), with a proportional fall in RV end-systolic elastance (Ees) (r=+0.70, 95% CI 0.44–0.85; P<0.0001), preserving RV-PA coupling (mean difference +0.08, 95% CI −0.11 to +0.26; P=0.42).
• Despite reduced global contractility (dP/dtmax, TAPSE, tricuspid annular velocity all decreased; P<0.001), RV free wall strain increased (+6.2%, 95% CI 4.5–7.8; P<0.0001) with improved fractional area change and right atrial performance at rest and exercise (P<0.0001).

Clinical Relevance: Reassures UK clinicians using sotatercept (recently approved for PAH) that apparent reductions in RV contractility reflect favourable afterload unloading rather than myocardial decompensation, with genuine improvement in functional RV/RA mechanics and exertional reserve.

Limitations: Small sample (n=30, single-arm, no control group) limits generalisability and causal inference regarding long-term RV remodelling.

Study Type: Prospective, multicentre, real-world registry (post-approval)

Key Question: Does the extravascular ICD (Aurora EV-ICD) maintain the safety and efficacy demonstrated in premarket trials when used in broader real-world clinical practice with an expanded implanter base?

Key Findings:

• Successful implantation achieved in 96.3% of 787 patients (758/787) across 168 implanters; 1-year freedom from major system/procedure-related complications was 89.1% (95% CI, 86.3–91.3%).
• Shock success for spontaneous VT/VF episodes was 100% (61/61); antitachycardia pacing success for monomorphic VT was 74.2%.
• First appropriate therapy occurred in 7.3% (95% CI, 5.5–9.6%) at 1 year; inappropriate shocks occurred in 7.1% (95% CI, 5.4–9.4%), mainly due to noncardiac oversensing (40.5%).

Clinical Relevance: Provides reassurance for UK implanters considering EV-ICD as a lead-management-sparing alternative to transvenous or subcutaneous ICDs, confirming comparable real-world performance to pivotal trial data as adoption widens across NHS cardiac device services.

Limitations: Non-randomised registry design without a comparator arm limits causal inference regarding relative safety/efficacy versus existing ICD platforms.

Study Type: Retrospective nationwide cohort study

Key Question: Does FFR-CT independently predict future cardiovascular events (MI, cardiovascular/all-cause death, revascularisation) in patients with stable coronary artery disease, beyond conventional risk factors and stenosis severity?

Key Findings:

• In 7,836 patients (27 English sites, 2017–2020), lower stenosis-specific FFR-CT was associated with graded increases in MI (HR 2.08–5.73), cardiovascular death (HR 1.51–3.40), and revascularisation (HR 4.79–24.48), all p<0.001.
• After adjusting for risk factors and CAD-RADS stenosis severity, FFR-CT ≤0.7 remained independently associated with MI (aHR 2.94–3.39) and ≤0.5 with cardiovascular death (aHR 2.92) and all-cause death (aHR 1.49).
• FFR-CT improved discrimination for MI/cardiovascular death (C-index 0.783, ΔC-index 0.012, p<0.001); optimal risk threshold identified at 0.67, with low event rates (1.5%) when stenosis-specific FFR-CT was normal despite discordant distal values.

Clinical Relevance: Supports wider NHS adoption of FFR-CT not just for diagnostic triage but as an independent prognostic tool to risk-stratify stable CAD patients and guide intensity of secondary prevention or revascularisation decisions.

Limitations: Retrospective, registry-based design with clinically indicated (non-randomised) FFR-CT testing introduces selection bias and potential unmeasured confounding.

Study Type: Basic/translational science study (in vitro cardiomyocyte models and in vivo mouse models)

Key Question: Does the lysosomal protein LAPTM4A regulate mTORC1-driven protein synthesis and contribute to pathological cardiac hypertrophy, and can this axis be therapeutically targeted?

Key Findings:

• LAPTM4A overexpression promoted cardiomyocyte hypertrophy and worsened cardiac remodelling/dysfunction by enhancing mTORC1-p70S6K/4EBP1 signalling via NEDD4L-mediated K63-linked ubiquitination of AKT (autophagy unaffected).
• Cardiomyocyte-specific LAPTM4A knockout significantly reduced hypertrophy and fibrosis in a transverse aortic constriction mouse model.
• A drug-repurposing screen identified magnolol, an FDA-approved compound, as a LAPTM4A suppressor with cardioprotective effects in vivo.

Clinical Relevance: This identifies a novel druggable axis (LAPTM4A-mTORC1-AKT) underlying pathological hypertrophy, offering a potential future pharmacological strategy relevant to heart failure prevention pathways within NHS cardiology research pipelines.

Limitations: Findings are preclinical (rodent/cell-based), and human translational and safety/efficacy data for magnolol are lacking.

Study Type: Preclinical mechanistic study (murine models and cardiomyocyte cell cultures)

Key Question: Does ALKBH5-mediated m6A RNA demethylation drive cardiac aging, and can this pathway be therapeutically targeted?

Key Findings:

• ALKBH5 was upregulated with reduced global m6A levels in physiologically aged and paraquat-induced aged hearts and senescent cardiomyocytes.
• Prophylactic (but not late-stage) ALKBH5 knockdown via AAV9-shRNA attenuated cardiac remodeling, dysfunction, and senescence phenotypes.
• Mechanistically, ALKBH5 reduced SLC38A3 (YTHDC2-dependent), impairing glutamine accumulation and mitochondrial homeostasis; SLC38A3 overexpression or glutamine supplementation reversed aging phenotypes.

Clinical Relevance: Identifies the ALKBH5–SLC38A3–glutamine axis as a novel, potentially modifiable pathway underlying age-related cardiac remodeling, offering a future therapeutic target relevant to the growing burden of heart failure with preserved ejection fraction in an ageing UK population.

Limitations: Findings are derived solely from animal and cell models, with no human validation, and efficacy was seen only when intervention began before aging onset, limiting translational applicability to established cardiac aging.

Study Type: Basic/translational science (murine knockout and overexpression models with mechanistic in vitro/in vivo experiments)

Key Question: Does the E3 ubiquitin ligase Asb2 regulate autophagic flux and mitochondrial homeostasis to protect against cardiac hypertrophy and heart failure?

Key Findings:

• Asb2β expression was reduced in human cardiomyopathy and hypertrophic mouse hearts; cardiomyocyte-specific Asb2 knockout in adult mice spontaneously induced hypertrophy, heart failure, and dysfunctional mitochondrial accumulation.
• Asb2 loss impaired ubiquitin-mediated degradation of KIF11, causing peripheral lysosomal mislocalisation, disrupted autophagosome-lysosome fusion, and impaired late-stage autophagy.
• AAV9-mediated Asb2 restoration or genetic/pharmacological KIF11 inhibition reversed pressure-overload (TAC) and age-related cardiac remodeling, restoring autophagic flux and mitochondrial function.

Clinical Relevance: Identifies the Asb2-KIF11 axis as a novel, druggable pathway for restoring mitochondrial quality control—relevant to future NHS heart failure therapeutics targeting autophagy-lysosomal dysfunction rather than symptomatic management alone.

Limitations: Findings are derived entirely from male mouse models and cell-based mechanistic studies, with no human clinical data to confirm translational efficacy or safety.

Study Type: Narrative review

Key Question: How should acute coronary syndrome (ACS) be diagnosed and managed in patients with Kawasaki disease (KD)-associated coronary artery aneurysms, given that standard atherosclerotic ACS guidelines do not apply?

Key Findings:

• KD-associated ACS arises from distinct mechanisms (aneurysm thrombosis, stenosis, calcification) rather than plaque rupture, requiring tailored diagnostic and imaging approaches (e.g., intracoronary imaging).
• Management demands combined paediatric and adult cardiology input across revascularisation strategy, antithrombotic therapy selection, and long-term surveillance.
• No KD-specific ACS guidelines currently exist; recommendations are extrapolated from limited evidence and expert consensus.

Clinical Relevance: As KD survivors with coronary aneurysms increasingly transition into UK adult cardiology and congenital heart disease services, clinicians must recognise KD-specific ACS presentations and avoid inappropriate application of standard atherosclerotic ACS pathways.

Limitations: As a narrative review, it synthesises heterogeneous evidence without systematic methodology, and robust randomised data specific to KD-ACS management remain lacking.

Study Type: Pooled individual patient data analysis of six RCTs (retrospective/secondary analysis)

Key Question: What patient- and treatment-related factors predict intracranial haemorrhage (ICH) after weight-adjusted tenecteplase fibrinolysis for STEMI, and can these be modelled for individual risk prediction?

Key Findings:

• Among 15,954 patients, 169 (1.1%) developed ICH; risk rose 2% per mmHg above SBP 110 mmHg (aOR 1.02, 95% CI 1.01–1.03), accelerating sharply above 160 mmHg.
• Age-related risk was dose-dependent: ICH risk increased from ~1%/year with 30 mg TNK to ~7%/year with 50 mg.
• Female sex (aOR 1.49) and lower body weight (aOR 1.16 per 5 kg decrease) independently increased risk; model discrimination was moderate (C-index 0.718).

Clinical Relevance: Supports pre-treatment SBP optimisation and age-adjusted TNK dose reduction as practical, modifiable strategies to reduce ICH risk in UK primary fibrinolysis pathways (e.g., pre-hospital/rural STEMI networks where PCI access is delayed).

Limitations: Retrospective pooling across trials with differing eras/protocols limits generalisability, and model discrimination, while adequate, is not highly precise for individual-level decision-making.