Ivabradine

證據等級: L5

預測適應症: 10 個

Ivabradine: From Stable Angina and Heart Failure to Pulmonary Hypertension

One-Sentence Summary

Ivabradine is an If (funny current) channel blocker used internationally for stable angina and chronic heart failure with reduced ejection fraction, selectively lowering heart rate without affecting myocardial contractility. Whilst the TxGNN model’s highest-ranked predictions (ranks 1–6) are likely knowledge graph false positives driven by Ivabradine’s known trichomegaly side effect propagating through hair-disease nodes, pulmonary hypertension emerges as the most clinically compelling repurposing candidate (rank 7, TxGNN score 98.50%), supported by 3 clinical trials and 20 publications — including both animal studies and small human clinical series demonstrating right ventricular function improvement.

Quick Overview

Item	Content
Original Indication	Stable angina; chronic heart failure with reduced ejection fraction (HFrEF) — international approvals (not registered in Australia)
Predicted New Indication	Pulmonary Hypertension
TxGNN Prediction Score	98.50%
Evidence Level	L3
Australia Market Status	Not marketed
Number of ARTG Entries	0
Recommended Decision	Proceed with Guardrails

Why is This Prediction Reasonable?

Currently, detailed mechanism of action data is not available in the provided DrugBank record. Based on well-established clinical pharmacology, Ivabradine selectively inhibits the hyperpolarisation-activated cyclic nucleotide-gated (HCN) channel current — the “If current” — in sinoatrial node pacemaker cells. The result is a pure reduction in resting and exercise heart rate without negative inotropy, negative dromotropy, or blood pressure effects. This unique haemodynamic profile distinguishes it from beta-blockers and calcium channel antagonists.

In pulmonary hypertension, the right ventricle (RV) faces chronically elevated afterload due to raised pulmonary vascular resistance. Compensatory tachycardia is nearly universal but is ultimately counterproductive: shortened diastolic filling time impairs RV perfusion and filling, accelerating RV failure. Heart rate reduction with Ivabradine extends diastolic duration, improving RV coronary perfusion, reducing RV oxygen demand, and restoring more favourable biventricular interactions. This mechanism has been validated in rat models using both monocrotaline (MCT) and SU5416/hypoxia PAH protocols, where Ivabradine reduced RV fibrosis and improved RV function independently of beta-blockade effects.

Translational data from small clinical series add weight to the hypothesis. Studies in systemic sclerosis–related PAH reported improvements in six-minute walk distance and reductions in pulmonary vascular resistance following Ivabradine treatment. A controlled clinical study in COPD patients with cor pulmonale demonstrated statistically significant pulmonary pressure reductions within two weeks. These findings, combined with the mechanistic plausibility of pure heart rate reduction in a pressure-overloaded RV, provide sufficient biological rationale for formal investigation.

Note on top-ranked TxGNN predictions: Ranks 1–6 and ranks 8–10 (hypertrichosis, Ambras syndrome, hair shaft abnormalities, Dandy-Walker malformation, periodontal syndromes, leprosy) are assessed as knowledge graph false positives. Trichomegaly — eyelash overgrowth — is a recognised ~1% adverse effect of Ivabradine. This side-effect node appears to have propagated through the TxGNN graph to adjacent hair, skin, and craniofacial disease nodes, producing spuriously high prediction scores with no supporting biological rationale or literature. These predictions should not be pursued clinically.

Clinical Trial Evidence

Trial Number	Phase	Status	Enrolment	Key Findings
NCT03650205	N/A	Unknown	160	Ivabradine vs. no Ivabradine for prevention of anthracycline-induced cardiotoxicity; cardioprotective mechanism via HR reduction relevant to chemotherapy-associated RV dysfunction and secondary PH
NCT00757055	Phase 2	Withdrawn (0 enrolled)	0	Ivabradine in diastolic heart failure (HFpEF); withdrawn before enrolment but the protocol demonstrates scientific rationale for If channel blockade in chronic cardiac dysfunction including Group 2 PH
NCT04735354	N/A	Completed	268	Real-world Sacubitril/Valsartan in HFrEF (India); Ivabradine co-prescribing common in this HF cohort with potential PH comorbidity — provides background population context only

Literature Evidence

PMID	Year	Type	Journal	Key Findings
32915674	2020	Animal/Experimental	Am J Respir Cell Mol Biol	Ivabradine 10 mg/kg/d reduced RV fibrosis and improved RV systolic function in MCT and SU5416/hypoxia rat PH models — HR reduction benefit independent of β-blockade
29146614	2018	Animal/Experimental	Am J Physiol Heart Circ Physiol	Ivabradine improved biventricular function and interventricular interactions in experimental PAH; restored septal position and cardiac cycle timing
37742537	2023	Clinical Observational	Am J Cardiol	Ivabradine improved RV systolic function in COPD patients with cor pulmonale; prospective design with haemodynamic endpoints
22792738	2012	Clinical Study	Kardiologiia	Ivabradine 10 mg/day significantly lowered pulmonary hypertension severity in 60 COPD Stage III–IV patients over 2 weeks; controlled comparison
24556029	2014	Clinical Series/Pilot	J Card Fail	Functional improvement in PAH patients treated with Ivabradine; 6-minute walk distance and pulmonary vascular resistance improvements reported
23389056	2013	Clinical Series	Clin Res Cardiol	Ivabradine in PAH: potential to delay need for parenteral prostanoid therapy; small series but clinically significant endpoint
23021874	2012	Case Series	Eur J Intern Med	Ivabradine in systemic sclerosis–related PAH; haemodynamic improvements with acceptable tolerability
22383181	2012	Case Report/Series	Clin Res Cardiol	Safe and well-tolerated Ivabradine use in systemic sclerosis patients with pulmonary hypertension
28701278	2017	Review	Eur J Intern Med	Ivabradine as supportive therapy in PH alongside ACE inhibitors, ARBs, and beta-blockers; safety and tolerability summary
32248556	2020	Scoping Review	Pharmacotherapy	Comprehensive scoping review of novel uses of Ivabradine beyond HF and ischaemic heart disease, including PH contexts

Australia Market Information

Ivabradine is currently not registered in Australia. There are no ARTG entries on record with the TGA.

Internationally, Ivabradine is marketed as Coralan® (Servier) and is approved in the European Union and multiple Asia-Pacific markets for stable angina and chronic HFrEF (sinus rhythm ≥75 bpm). No TGA registration has been submitted or granted.

Any Australian clinical use would require either a TGA marketing authorisation or access via the Special Access Scheme (SAS) Category B pathway for individual patient use in the context of clinical investigation.

Safety Considerations

No TGA-approved Australian Product Information (PI) is available. The following key safety considerations are drawn from international regulatory summaries (EMA SmPC for Coralan®) and are particularly relevant to the pulmonary hypertension context:

Bradycardia risk: Excessive heart rate reduction risks haemodynamic decompensation in PH patients who may depend on compensatory tachycardia to maintain cardiac output. Clinical evidence supports restricting use to patients with resting HR >80 bpm and preserved RV function.
Contraindications: Resting HR <60 bpm at baseline, sick sinus syndrome, sinoatrial block, complete AV block, acute myocardial infarction, severe hypotension.
Known adverse effect — trichomegaly: Eyelash overgrowth in approximately 1% of patients; reversible on discontinuation. Note: this side effect is the likely source of false-positive TxGNN predictions for hair disorders.
Visual phosphenes: Transient luminous phenomena reported in up to 14% of patients; generally mild, dose-dependent, and reversible.
CYP3A4 interactions: Ivabradine is a CYP3A4 substrate; concomitant use of strong CYP3A4 inhibitors (e.g., azole antifungals, macrolide antibiotics, HIV protease inhibitors) is contraindicated due to risk of profound bradycardia.

Please refer to the EMA Summary of Product Characteristics for Coralan® for complete prescribing information until an Australian TGA PI becomes available.

Conclusion and Next Steps

Decision: Proceed with Guardrails

Rationale: Converging animal model data and multiple small clinical series demonstrate that Ivabradine-mediated heart rate reduction consistently improves right ventricular function and haemodynamic parameters in pulmonary hypertension, providing a plausible biological mechanism and early clinical signal. However, the absence of completed Phase 2/3 RCTs specifically in PH, the lack of any TGA registration, and the potential for haemodynamic harm from inappropriate patient selection require careful guardrails before Australian clinical use.

To proceed, the following is needed:

Regulatory pathway: File a TGA marketing authorisation application or establish a Special Access Scheme (SAS) Category B approval framework for research use
Patient selection criteria: Define eligibility strictly — resting HR >80 bpm, confirmed PH (mPAP >20 mmHg on right heart catheterisation), preserved RV function (TAPSE >17 mm or RV FAC >35%)
Prospective clinical investigation: Design a pilot RCT or structured observational study in Australian PH specialist centres (e.g., St Vincent’s Hospital Sydney, Alfred Hospital Melbourne) targeting Group 1 PAH or Group 2 PH-HFpEF populations
Safety monitoring plan: Pre-specified stopping rules based on cardiac output monitoring; echocardiographic RV function assessment at baseline, 4 weeks, and 12 weeks
Full MOA and safety data retrieval: Obtain complete DrugBank entry and EMA SmPC for formal pharmacovigilance assessment
Mechanism of action verification: Confirm HCN channel expression profile in pulmonary vasculature and RV myocardium to strengthen biological rationale
Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.