Heart Diseases: A Modern Challenge
Coronary artery disease (CAD), including myocardial infarction (MI), and associated complications such as chronic heart failure remain leading causes of morbidity and mortality worldwide [1, 2, 3, 4, 6, 8]. Despite significant advances in cardiology, particularly in reperfusion therapy for acute myocardial infarction, many patients still face irreversible myocardial damage and adverse ventricular remodeling [3, 4]. Current treatment methods are often unable to fully restore damaged heart tissue, dictating the need to search for new, more effective regenerative strategies [3].
Stem Cells: Hope for Heart Regeneration
For decades, research in stem cell therapy has demonstrated promising results in preclinical models, indicating their potential in cardiomyocyte regeneration and tissue remodeling [2, 3]. Stem cells, particularly mesenchymal stromal cells (MSCs) and bone marrow-derived stem cells (BMSCs), are drawing special attention due to their differentiation capacity and paracrine action [1, 3, 4, 6]. These cells can become the key to restoring heart function and preventing the development of heart failure after an infarction [3, 6].
Mechanisms of Action: How Stem Cells Repair the Heart
The therapeutic effect of stem cells is driven by several key mechanisms:
- Cardiomyocyte regeneration: Growing evidence shows that stem cells, such as MSCs, can generate new cardiomyocytes in both animals and humans [3]. This is critical for restoring lost heart muscle tissue.
- Paracrine effects: MSCs release exosomes containing microRNAs (exo-miRs) that play a therapeutic role in models of coronary artery disease [1]. These microRNAs regulate paracrine activity, promoting tissue repair and reducing inflammation [1, 2]. In preclinical studies, bone marrow-derived MSCs are most frequently used, and ultracentrifugation is typically applied for exosome extraction [1].
- Tissue remodeling: Stem cells promote favorable myocardial remodeling, which helps prevent further deterioration of heart function after injury [2].
- Modulation of cellular activity: They are capable of reducing the excessive activation of cardiomyocytes and cardiac fibroblasts that worsens the prognosis after tissue necrosis [2].
- microRNAs shuttled by mesenchymal stromal cell-derived exosomes in coronary artery disease: A systematic review of preclinical studies. https://pubmed.ncbi.nlm.nih.gov/41064388/
- Electroactive microneedle augmented stem cell therapy in myocardial infarction. https://pubmed.ncbi.nlm.nih.gov/42090513/
- Stem cells for the heart, are we there yet? https://pubmed.ncbi.nlm.nih.gov/14713729/
- Efficacy and Safety of Intracoronary Mesenchymal Stem Cell Administration in ST-Segment Elevation Acute Myocardial Infarction: A Meta-Analysis of Randomized Controlled Trials. https://pubmed.ncbi.nlm.nih.gov/42499248/
- Prevention of acute myocardial infarction induced heart failure by intracoronary infusion of mesenchymal stem cells: phase 3 randomised clinical trial (PREVENT-TAHA8). https://pubmed.ncbi.nlm.nih.gov/41224473/
- Bone marrow-derived stem cells for acute myocardial infarction: a systematic review and meta-analysis on efficacy and safety. https://pubmed.ncbi.nlm.nih.gov/42363037/
- Stem cell therapy for patients with acute myocardial infarction: a systematic review of clinical trials. https://pubmed.ncbi.nlm.nih.gov/41469916/
Clinical Studies and Application Prospects
Despite promising preclinical results, the translation of cell therapy into clinical practice faces several challenges, such as limited stem cell engraftment and insufficient stimulation of resident cardiomyocytes [2]. Nevertheless, clinical trials are ongoing, demonstrating encouraging results.
A systematic review and meta-analysis of randomized controlled trials (RCTs) on intracoronary administration of MSCs in patients with ST-segment elevation myocardial infarction (STEMI) showed a significant improvement in left ventricular ejection fraction (LVEF) [4]. This analysis included eight RCTs involving 796 patients, and the results confirmed the safety and efficacy of MSCs in improving cardiac function without increasing mortality [4].
Another systematic review and meta-analysis focusing on BMSCs in acute myocardial infarction, which included 25 studies with 1,822 patients, also showed that BMSC transplantation significantly improves LVEF, reduces the rate of major adverse cardiac events (MACE), repeat hospitalizations, and mortality [6].
Large-scale studies are currently underway, such as the phase 3 randomized clinical trial PREVENT-TAHA8, aimed at evaluating the effect of intracoronary infusion of allogeneic Wharton's jelly-derived MSCs on the development of heart failure after myocardial infarction [5]. This study involves 420 patients with a first STEMI and an LVEF of less than 40%, who receive MSCs within 3-7 days post-infarction in addition to standard therapy [5].
A systematic review of clinical trials on cell therapy in acute myocardial infarction identified 43 eligible studies, highlighting significant variability in cell types, timing and routes of administration, and dosages, which may impact therapy efficacy [8].
Innovative Delivery and Activation Approaches
To overcome challenges related to limited stem cell engraftment and insufficient resident cell activation, new approaches are being developed. One such innovative solution is an implantable electroactive microneedle-based device [2]. This piezoelectric microneedle patch, featuring an 80-cubic-millimeter volume cavity, allows for the efficient delivery of 1.5 × 105 mesenchymal stem cells directly to the infarction area and ensures their longer retention for continuous paracrine action [2]. Furthermore, piezoelectric stimulation generated by the polylactic acid microneedle matrix further enhances the action of stem cells, promoting more effective heart repair [2].
Safety and Efficacy: What the Data Show
Clinical studies and meta-analyses confirm that stem cell therapy, particularly with MSCs and BMSCs, is safe and effective for patients with acute myocardial infarction [4, 6]. Administration of MSCs significantly improves LVEF and reduces the rate of major adverse cardiac events (MACE) without increasing mortality [4]. Similarly, BMSC transplantation showed improved LVEF and reduced MACE, repeat hospitalizations, and mortality [6]. These findings underscore the potential of stem cells as an important component of future heart disease treatment strategies.
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The information provided in this article is for reference purposes only and cannot replace an in-person consultation with a qualified medical professional. All treatment decisions must be made only after consulting a physician.