PICSO: from myocardial salvage to tissue regeneration

Coronary sinus reducer for the treatment of refractory angina (ORBITA-COSMIC): a randomised, placebo-controlled trial

BACKGROUND

The coronary sinus reducer (CSR) is proposed to reduce angina in patients with stable coronary artery disease by improving myocardial perfusion. We aimed to measure its efficacy, compared with placebo, on myocardial ischaemia reduction and symptom improvement.

METHODS

ORBITA-COSMIC was a double-blind, randomised, placebo-controlled trial conducted at six UK hospitals. Patients aged 18 years or older with angina, stable coronary artery disease, ischaemia, and no further options for treatment were eligible. All patients completed a quantitative adenosine-stress perfusion cardiac magnetic resonance scan, symptom and quality-of-life questionnaires, and a treadmill exercise test before entering a 2-week symptom assessment phase, in which patients reported their angina symptoms using a smartphone application (ORBITA-app). Patients were randomly assigned (1:1) to receive either CSR or placebo. Both participants and investigators were masked to study assignment. After the CSR implantation or placebo procedure, patients entered a 6-month blinded follow-up phase in which they reported their daily symptoms in the ORBITA-app. At 6 months, all assessments were repeated. The primary outcome was myocardial blood flow in segments designated ischaemic at enrolment during the adenosine-stress perfusion cardiac magnetic resonance scan. The primary symptom outcome was the number of daily angina episodes. Analysis was done by intention-to-treat and followed Bayesian methodology. The study is registered with ClinicalTrials.gov, NCT04892537, and completed.

FINDINGS

Between May 26, 2021, and June 28, 2023, 61 patients were enrolled, of whom 51 (44 [86%] male; seven [14%] female) were randomly assigned to either the CSR group (n=25) or the placebo group (n=26). Of these, 50 patients were included in the intention-to-treat analysis (24 in the CSR group and 26 in the placebo group). 454 (57%) of 800 imaged cardiac segments were ischaemic at enrolment, with a median stress myocardial blood flow of 1·08 mL/min per g (IQR 0·77-1·41). Myocardial blood flow in ischaemic segments did not improve with CSR compared with placebo (difference 0·06 mL/min per g [95% CrI -0·09 to 0·20]; Pr(Benefit)=78·8%). The number of daily angina episodes was reduced with CSR compared with placebo (OR 1·40 [95% CrI 1·08 to 1·83]; Pr(Benefit)=99·4%). There were two CSR embolisation events in the CSR group, and no acute coronary syndrome events or deaths in either group.

INTERPRETATION

ORBITA-COSMIC found no evidence that the CSR improved transmural myocardial perfusion, but the CSR did improve angina compared with placebo. These findings provide evidence for the use of CSR as a further antianginal option for patients with stable coronary artery disease.

FUNDING

Medical Research Council, Imperial College Healthcare Charity, National Institute for Health and Care Research Imperial Biomedical Research Centre, St Mary's Coronary Flow Trust, British Heart Foundation.

Cardioprotective Strategies After Ischemia-Reperfusion Injury

Acute myocardial infarction (AMI) is associated with high morbidity and mortality worldwide. Although early reperfusion is the most effective strategy to salvage ischemic myocardium, reperfusion injury can develop with the restoration of blood flow. Therefore, it is important to identify protection mechanisms and strategies for the heart after myocardial infarction. Recent studies have shown that multiple intracellular molecules and signaling pathways are involved in cardioprotection. Meanwhile, device-based cardioprotective modalities such as cardiac left ventricular unloading, hypothermia, coronary sinus intervention, supersaturated oxygen (SSO2), and remote ischemic conditioning (RIC) have become important areas of research. Herein, we review the molecular mechanisms of cardioprotection and cardioprotective modalities after ischemia-reperfusion injury (IRI) to identify potential approaches to reduce mortality and improve prognosis in patients with AMI.

A novel therapy in microvascular obstruction in ST-elevation myocardial infarction: pressure-controlled intermittent coronary sinus occlusion therapy

Percutaneous coronary intervention has transformed the management of ST-elevation myocardial infarction (STEMI) due to a reduction in early mortality and need for repeat revascularization. However, the conventional revascularization strategy, combined with state-of-the-art anti-thrombotic and antiplatelet therapies, can still be associated with poor clinical outcome in some patients, because of reperfusion injury and microvascular obstruction contributing to the infarct size. To address this important therapeutic need, a broad-range of device-based treatments have been introduced. This is an overview of the pressure-controlled intermittent coronary sinus occlusion (PiCSO) device (Miracor Medical SA) which has been proposed for STEMI patients. PiCSO therapy could lead to an improved perfusion, decrease microvascular dysfunction, and thus potentially reduce infarct size.

Cost-effectiveness analysis of pressure-controlled intermittent coronary sinus occlusion in elective percutaneous coronary intervention

OBJECTIVES

Percutaneous coronary intervention (PCI) represents the standard treatment for ST-elevated myocardial infarction, nevertheless, mortality and heart failures are frequent. Pressure-controlled intermittent coronary sinus occlusion (PiCSO) might reduce infarct size showing better patients' outcomes. We evaluated the cost-effectiveness of PCI+PiCSO compared to PCI from the National Healthcare Service (NHS) perspective in Italy.

METHODS

A Markov model was developed to estimate life years (LYs), quality-adjusted life years (QALYs) and costs. A micro-costing analysis has been performed to inform the cost of PCI+PiCSO procedure. Sensitivity analyses were performed to test the robustness of the model results.

RESULTS

Considering a willingness-to-pay threshold of 50,000€/QALY for the ICUR and a cost for PCI+PiCSO procedure of 14,654€, the innovative strategy may be cost-effective compared to PCI alone from the Italian NHS perspective, showing an ICUR of 17,530€/QALY (ICER 14,631€/LY) over a lifetime horizon; the probabilistic sensitivity analysis showed that PCI+PiCSO is cost-effective in 78.8% of simulations.Considering the above mentioned willingness-to-pay threshold, PCI+PiCSO strategy would be cost-effective over a lifetime horizon considering a cost for PCI+PiCSO procedure lower than 28,160€.

CONCLUSION

PCI+PiCSO procedure may be considered a cost-effective technology that allows reducing cardiac events, while improving patients' life expectancy and quality of life.

Signs and signals limiting myocardial damage using PICSO: a scoping review decoding paradigm shifts toward a new encounter

Background

Inducing recovery in myocardial ischemia is limited to a timely reopening of infarct vessels and clearing the cardiac microcirculation, but additional molecular factors may impact recovery.

Objective

In this scoping review, we identify the paradigm shifts decoding the branching points of experimental and clinical evidence of pressure-controlled intermittent coronary sinus occlusion (PICSO), focusing on myocardial salvage and molecular implications on infarct healing and repair.

Design

The reporting of evidence was structured chronologically, describing the evolution of the concept from mainstream research to core findings dictating a paradigm change. All data reported in this scoping review are based on published data, but new evaluations are also included.

Results

Previous findings relate hemodynamic PICSO effects clearing reperfused microcirculation to myocardial salvage. The activation of venous endothelium opened a new avenue for understanding PICSO. A flow-sensitive signaling molecule, miR-145-5p, showed a five-fold increase in porcine myocardium subjected to PICSO.Verifying our theory of "embryonic recall," an upregulation of miR-19b and miR-101 significantly correlates to the time of pressure increase in cardiac veins during PICSO (r2 = 0.90, p < 0.05; r2 = 0.98, p < 0.03), suggesting a flow- and pressure-dependent secretion of signaling molecules into the coronary circulation. Furthermore, cardiomyocyte proliferation by miR-19b and the protective role of miR-101 against remodeling show another potential interaction of PICSO in myocardial healing.

Conclusion

Molecular signaling during PICSO may contribute to retroperfusion toward deprived myocardium and clearing the reperfused cardiac microcirculation. A burst of specific miRNA reiterating embryonic molecular pathways may play a role in targeting myocardial jeopardy and will be an essential therapeutic contribution in limiting infarcts in recovering patients.

Device-Based Approaches Targeting Cardioprotection in Myocardial Infarction: The Expanding Armamentarium of Innovative Strategies

Coronary reperfusion therapy has played a pivotal role for reducing mortality and heart failure after acute myocardial infarction. Although several adjunctive approaches have been studied for reducing infarct size further, both ischemia-reperfusion injury and microvascular obstruction are still major contributors to both early and late clinical events after acute myocardial infarction. The progress in the field of cardioprotection has found several promising proof-of-concept preclinical studies. However, translation from bench to bedside has not been very successful. This comprehensive review discusses the importance of infarct size as a driver of clinical outcomes post-acute myocardial infarction and summarizes recent novel device-based approaches for infarct size reduction. Device-based interventions including mechanical cardiac unloading, myocardial cooling, coronary sinus interventions, supersaturated oxygen therapy, and vagal stimulation are discussed. Many of these approaches can modify ischemic myocardial biology before reperfusion and offer unique opportunities to target ischemia-reperfusion injury.

Pressure-Controlled Intermittent Coronary Sinus Occlusion: A Novel Approach to Improve Microvascular Flow and Reduce Infarct Size in STEMI

Despite successful primary percutaneous coronary intervention (PCI) for treatment of ST-segment elevation myocardial infarction (STEMI), myocardial salvage is frequently suboptimal resulting in large infarctions with increased rates of heart failure and death. Microvascular dysfunction after the procedure is frequently present and contributes directly to poor outcomes in STEMI. Pressure-controlled intermittent Coronary Sinus Occlusion (PiCSO) is a novel technology designed to mitigate microvascular dysfunction in STEMI. Non-randomized studies have suggested that PiCSO use during primary PCI in STEMI is safe, improves microvascular perfusion and reduces infarct size. Randomized trials are ongoing to investigate the safety and effectiveness of PiCSO in high-risk patients with anterior STEMI undergoing primary PCI.

Role of PDGF-A/B Ligands in Cardiac Repair After Myocardial Infarction

Platelet-derived growth factors (PDGFs) are powerful inducers of cellular mitosis, migration, angiogenesis, and matrix modulation that play pivotal roles in the development, homeostasis, and healing of cardiac tissues. PDGFs are key signaling molecules and important drug targets in the treatment of cardiovascular disease as multiple researchers have shown that delivery of recombinant PDGF ligands during or after myocardial infarction can reduce mortality and improve cardiac function in both rodents and porcine models. The mechanism involved cannot be easily elucidated due to the complexity of PDGF regulatory activities, crosstalk with other protein tyrosine kinase activators, and diversity of the pathological milieu. This review outlines the possible roles of PDGF ligands A and B in the healing of cardiac tissues including reduced cell death, improved vascularization, and improved extracellular matrix remodeling to improve cardiac architecture and function after acute myocardial injury. This review may highlight the use of recombinant PDGF-A and PDGF-B as a potential therapeutic modality in the treatment of cardiac injury.

Coronary venous therapy to improve microvascular dysfunction

The coronary circulation is a complex system in which vascular resistances are determined by an interplay of forces in at least three compartments: the epicardial, the microvascular, and the venous district. Cardiologists, and particularly interventional cardiologists, normallly place the focus of their attention on diseases of the epicardial coronary circulation as possible causes of coronary syndromes and neglect the importance of the other two compartments of coronary circulation. The study of the coronary microcirculation, an increasingly recognized source of ischemia, has long been disregarded, but is witnessing a revival since the (re-)introduction of diagnostic tools in the better equipped catheterization laboratories. Unfortunately, to date our understanding of coronary microvascular disease remains incomplete and the numerous proposed classifications fail to reflect its complexity. Further, no specific therapy for these disorders is available. The coronary venous circulation is an even more neglected third vascular district. Its role in regulating coronary resistances is almost completely unexplored, but inital evidence suggests that the modulation of venous pressure might help improve coronary perfusion. Coronary sinus interventions are a group of invasive techniques (both surgical and catheter-based) that are designed to treat ischaemic heart disease by increasing coronary venous pressure and therefore redistributing coronary blood flow towards the endocardium. In this review paper, we revise the role of these interventions with particular focus on acute and chronic coronary microvascular disease.

Effect of Pressure-controlled intermittent Coronary Sinus Occlusion (PiCSO) on infarct size in anterior STEMI: PiCSO in ACS study

BACKGROUND

The aim of this clinical research was to investigate the effects of Pressure-controlled intermittent Coronary Sinus Occlusion (PiCSO) on infarct size at 5 days after primary percutaneous coronary intervention (pPCI) in patients with ST-segment elevation myocardial infarction (STEMI).

METHODS AND RESULTS

This comparative study was carried out in four UK hospitals. Forty-five patients with anterior STEMI presenting within 12 h of symptom onset received pPCI plus PiCSO (initiated after reperfusion; n = 45) and were compared with a propensity score-matched control cohort from INFUSE-AMI (n = 80). Infarct size (% of LV mass, median [interquartile range]) measured by cardiac magnetic resonance (CMR) at day 5 was significantly lower in the PiCSO group (14.3% [95% CI 9.2-19.4%] vs. 21.2% [95% CI 18.0-24.4%]; p = 0.023). There were no major adverse cardiac events (MACE) related to the PiCSO intervention.

CONCLUSIONS

PiCSO, as an adjunct to pPCI, was associated with a lower infarct size at 5 days after anterior STEMI in a propensity score-matched population.

The Reducer device in patients with angina pectoris: mechanisms, indications, and perspectives

Despite available pharmacological and interventional therapies, refractory angina is a common and disabling clinical condition, and a major public health problem, which affects patients' quality-of-life, and has a significant impact upon health care resources. Persistent angina is common not only in patients who are not good candidates for revascularization, but also in patients following successful revascularization. Clearly, there is a need for additional treatment options for refractory angina beyond currently available pharmacological and interventional therapies. It is of pivotal importance, in this condition, to practice a patient-centred health assessment approach, measuring success of a new therapy by its effects on patients' symptoms, functional status, and quality-of-life, rather than hard clinical endpoints as used in clinical studies. The coronary sinus Reducer is a novel technology designed to reduce disabling symptoms and improve quality-of-life of patients suffering from refractory angina. This review serves to update the clinician as to current evidence and future perspectives of the optimal utilization of this innovative technology.

Acute molecular effects of pressure-controlled intermittent coronary sinus occlusion in patients with advanced heart failure

Aims

Cardiac repair has steered clinical attention and remains an unmet need, because available regenerative therapies lack robust mechanistic evidence. Pressure‐controlled intermittent coronary sinus occlusion (PICSO), known to induce angiogenetic and vasoactive molecules as well as to reduce regional ischemia, may activate endogenous regenerative processes in failing myocardium. We aimed to investigate the effects of PICSO in patients with advanced heart failure undergoing cardiac resynchronization therapy.

Methods and results

Eight out of 32 patients were treated with PICSO, and the remainder served as controls. After electrode testing including left ventricular leads, PICSO was performed for 20 min. To test immediate molecular responses, in both patient groups, coronary venous blood samples were taken at baseline and after 20 min, the time required for the intervention. Sera were tested for microRNAs and growth factors. To test the ability of up‐regulated soluble factors on cell proliferation and expression of transcription factors [e.g. Krüppel‐like factor 4 (KLF‐4)], sera were co‐cultured with human cardiomyocytes and fibroblasts. As compared with controls, significant differential expression (differences between pre‐values and post‐values in relation to both patient cohorts) of microRNA patterns associated with cardiac development was observed with PICSO. Importantly, miR‐143 (P < 0.048) and miR‐145 (P < 0,047) increased, both targeting a network of transcription factors (including KLF‐4) that promote differentiation and repress proliferation of vascular smooth muscle cells. Additionally, an increase of miR‐19b (P < 0.019) known to alleviate endothelial cell apoptosis was found, whereas disadvantageous miR‐320b (P < 0.023) suspect to impair expression of c‐myc, normally provoking cell cycle re‐entry in post‐mitotic myocytes and miR‐25 (P < 0.023), decreased, a target of anti‐miR application to improve contractility in the failing heart. Co‐cultured post‐PICSO sera significantly increased cellular proliferation both in fibroblasts (P < 0.001) and adult cardiomycytes (P < 0.004) sampled from a transplant recipient as compared with controls. Adult cardiomyocytes showed a seven‐fold increase of the transcription factor KLF‐4 protein when co‐cultured with treated sera as compared with controls.

Conclusions

Here, we show for the first time that PICSO, a trans‐coronary sinus catheter intervention, is associated with an increase in morphogens secreted into cardiac veins, normally present during cardiac development, and a significant induction of cell proliferation. Present findings support the notion that epigenetic modifications, that is, haemodynamic stimuli on venous vascular cells, may reverse myocardial deterioration. Further investigations are needed to decipher the maze of complex interacting molecular pathways in failing myocardium and the potential role of PICSO to reinitiate developmental processes to prevent further myocardial decay eventually reaching clinical significance.

From state-of-the-art cell therapy to endogenous cardiac repair

Clinical heart failure prevention and contemporary therapy often involve breaking the vicious cycle of global haemodynamic consequences of myocardial decay. The lack of effective regenerative therapies results in a primary focus on preventing further deterioration of cardiac performance. The cellular transplantation hypothesis has been evaluated in many different preclinical models and a handful of important clinical trials. The primary expectation that cellular transplants will be embedded into failing myocardium and fuse with existing functioning cells appears unlikely. A multitude of cellular formulas, access routes and clinical surrogate endpoints for evaluation add to the complexity of cellular therapies. Several recent large clinical trials have provided insights into both the regenerative potential and clinical improvement from non-regenerative mechanisms. Initiating endogenous repair seems to be another meaningful alternative to recover structural integrity in myocardial injury. This option may be achieved using a transcoronary sinus catheter intervention, implying the understanding of basic principles in biology. With intermittent reduction of outflow in cardiac veins (PICSO), vascular cells appear to be activated and restart a programme similar to pathways in the developing heart. Structural regeneration may be possible without requiring exogenous agents, or a combination of both approaches may become clinical reality in the next decade.

MicroRNAs Mediate Beneficial Effects of Exercise in Heart

MicroRNAs (miRNAs, miRs), a group of small non-coding RNAs, repress gene expressions at posttranscriptional level in most cases and are involved in cardiovascular physiology and disease pathogenesis. Increasing evidence has proved that miRNAs are potential regulators of exercise induced cardiac growth and mediate the benefits of exercise in a variety of cardiovascular diseases. In this chapter, we will review the regulatory effects of miRNAs in cardiac adaptations to exercise, and summarize their cardioprotective effects against myocardial infarction, ischemia/reperfusion injury, heart failure, diabetic cardiomyopathy, atherosclerosis, hypertension, and pulmonary hypertension. Also, we will introduce circulating miRNAs in response to acute and chronic exercise. Therefore, miRNAs may serve as novel therapeutic targets and potential biomarkers for cardiovascular diseases.

Efficacy and Safety of Coronary Sinus Aspiration During Coronary Angiography to Attenuate the Risk of Contrast-Induced Acute Kidney Injury in Predisposed Patients

Background—

The incidence of contrast-induced acute kidney injury is strongly related to the amount of the given contrast. Our objectives were to evaluate the efficacy and safety of coronary sinus aspiration (CSA) procedure to reduce the volume of the given contrast and attenuate the risk of contrast-induced acute kidney injury.

Methods and Results—

The study included 43 patients with type 2 diabetes mellitus and renal impairment (creatinine 1.5–3 mg/dL) who were candidates for coronary angiography. Eighteen patients were subjected to CSA procedure during coronary angiography (CSA group), and 25 patients served as a control group. Periprocedural standard care was given. In CSA group, the coronary sinus was cannulated via subclavian or femoral venous approaches, and aspiration was done directly from a transseptal sheath (8 patients) or through a balloon occlusion catheter placed through the sheath (10 patients) simultaneously during each coronary injection. Estimated volume of aspirated contrast was calculated based on the percentage reduction in hematocrit value of the aspirate in relation to the patient’s baseline hematocrit. Fraction of aspirated contrast was calculated by dividing estimated volume of aspirated contrast over the volume of injected contrast×100. Both study groups were matched in clinical and laboratory data, as well as volume of injected contrast. In CSA group, mean fraction of aspirated contrast was 39.35±10.47%. One patient in the CSA group, compared with 9 patients in the control group, developed contrast-induced acute kidney injury ( P =0.028).

Conclusions—

CSA during coronary angiography could effectively remove more than one third of the given contrast and may reduce the incidence of contrast-induced acute kidney injury in selected patients.

Safety and efficacy of a device to narrow the coronary sinus for the treatment of refractory angina: A single-centre real-world experience

Objective

The coronary sinus Reducer is a recently introduced device to treat patients with severe angina symptoms refractory to optimal medical therapy and not amenable for conventional revascularisation. We aimed to assess the safety and efficacy of the Reducer in a real-world cohort of patients with refractory angina.

Methods

This is a single-centre retrospective registry. Patients with severe angina symptoms, objective evidence of myocardial ischaemia using any adequate non-invasive modality and without options for conventional revascularisation were regarded eligible for Reducer implantation.

Results

Twenty-three patients (74 % male, mean age 70 ± 8 years, 91.3 % previous bypass surgery, 82.6 % previous percutaneous intervention, 47.8 % previous myocardial infarction, 52.2 % diabetes mellitus) underwent Reducer implantation. The safety endpoint (successful implantation of the first device without device-related adverse events) was met in all patients. After a median follow-up of 9 (8–14) months the efficacy (any reduction in Canadian Cardiovascular Society (CCS) class and revascularisation-free survival) was reached in 17 patients (74 %): 8 patients (34.8 %) improved by 1 CCS class, 7 (30.4 %) by 2 CCS classes and 2 (8.7 %) by 3 CCS classes. One patient died 4 months after implantation because of progressive heart failure (not associated with Reducer implantation).

Conclusion

In this single-centre real-world experience, Reducer implantation was safe and demonstrated excellent clinical efficacy in the treatment of refractory angina at mid-term follow-up.

Exercise for the heart: signaling pathways

Physical exercise, a potent functional intervention in protecting against cardiovascular diseases, is a hot topic in recent years. Exercise has been shown to reduce cardiac risk factors, protect against myocardial damage, and increase cardiac function. This improves quality of life and decreases mortality and morbidity in a variety of cardiovascular diseases, including myocardial infarction, cardiac ischemia/reperfusion injury, diabetic cardiomyopathy, cardiac aging, and pulmonary hypertension. The cellular adaptation to exercise can be associated with both endogenous and exogenous factors: (1) exercise induces cardiac growth via hypertrophy and renewal of cardiomyocytes, and (2) exercise induces endothelial progenitor cells to proliferate, migrate and differentiate into mature endothelial cells, giving rise to endothelial regeneration and angiogenesis. The cellular adaptations associated with exercise are due to the activation of several signaling pathways, in particular, the growth factor neuregulin1 (NRG1)-ErbB4-C/EBPβ and insulin-like growth factor (IGF)-1-PI3k-Akt signaling pathways. Of interest, microRNAs (miRNAs, miRs) such as miR-222 also play a major role in the beneficial effects of exercise. Thus, exploring the mechanisms mediating exercise-induced benefits will be instrumental for devising new effective therapies against cardiovascular diseases.