Stem cell-derived sheet engineering has been developed as the next-generation treatment for myocardial infarction (MI) and offers attractive advantages in comparison with direct stem cell transplantation and scaffold tissue engineering. Furthermore, induced pluripotent stem cell-derived cell sheets have been indicated to possess higher potential for MI therapy than other stem cell-derived sheets because of their capacity to form vascularized networks for fabricating thickened human cardiac tissue and their long-term therapeutic effects after transplantation in MI. To date, stem cell sheet transplantation has exhibited a dramatic role in attenuating cardiac dysfunction and improving clinical manifestations of heart failure in MI. In this review, we retrospectively summarized the current applications and strategy of stem cell-derived cell sheet technology for heart tissue repair in MI.

Stem cell-based therapy has been used to treat ischaemic heart diseases for two decades. However, optimal cell types and transplantation methods remain unclear. This study evaluated the therapeutic effects of human umbilical cord mesenchymal stem cell (hUCMSC) sheet on myocardial infarction (MI). hUCMSCs expressing luciferase were generated by lentiviral transduction for in vivo bio-luminescent imaging tracking of cells. We applied a temperature-responsive cell culture surface-based method to form the hUCMSC sheet. Cell retention was evaluated using an in vivo bio-luminescent imaging tracking system. Unbiased transcriptional profiling of infarcted hearts and further immunohistochemical assessment of monocyte and macrophage subtypes were used to determine the mechanisms underlying the therapeutic effects of the hUCMSC sheet. Echocardiography and pathological analyses of heart sections were performed to evaluate cardiac function, angiogenesis and left ventricular remodelling. When transplanted to the infarcted mouse hearts, hUCMSC sheet significantly improved the retention and survival compared with cell suspension. At the early stage of MI, hUCMSC sheet modulated inflammation by decreasing Mcp1-positive monocytes and CD68-positive macrophages and increasing Cx3cr1-positive non-classical macrophages, preserving the cardiomyocytes from acute injury. Moreover, the extracellular matrix produced by hUCMSC sheet then served as bioactive scaffold for the host cells to graft and generate new epicardial tissue, providing mechanical support and routes for revascularsation. These effects of hUCMSC sheet treatment significantly improved the cardiac function at days 7 and 28 post-MI. hUCMSC sheet formation dramatically improved the biological functions of hUCMSCs, mitigating adverse post-MI remodelling by modulating the inflammatory response and providing bioactive scaffold upon transplantation into the heart. Due to its excellent availability as well as superior local cellular retention and survival, allogenic transplantation of hUCMSC sheets can more effectively acquire the biological functions of hUCMSCs, such as modulating inflammation and enhancing angiogenesis. Moreover, the hUCMSC sheet method allows the transfer of an intact extracellular matrix without introducing exogenous or synthetic biomaterial, further improving its clinical applicability.

Following myocardial infarction (MI), the accumulation of CD86-positive macrophages in the ischemic injury zone leads to secondary myocardial damage. Precise pharmacological intervention targeting this process remains challenging. This study engineered a nanotherapeutic delivery system with CD86-positive macrophage-specific targeting and ultrasound-responsive release capabilities. A folic acid (FA)–modified ultrasound-responsive gene/drug delivery system, assembled from DOTAP, DSPE-PEG2000-FA, cholesterol, and perfluorohexane (PFH)—termed FA-PNBs—was developed to codeliver small interfering RNA of STAT1 (siSTAT1) and the small-molecule nitro-oleic acid (OA-NO ₂ ) into CD86-positive macrophages. Upon irradiation with low-intensity focused ultrasound, FA-PNBs release siSTAT1 and OA-NO ₂ at the ischemic injury zone. The results demonstrated the system’s precise targeting and efficient delivery capabilities. The combined modulation of OA-NO ₂ and siSTAT1 optimizes the immune microenvironment in the infarcted region, alleviates ventricular remodeling, preserves cardiac function, and holds promise for clinical intervention strategies after MI.

Despite sternum sparing and without cardiopulmonary bypass, the actual value of minimally invasive coronary surgery (MICS) is still debatable. This study aimed to compare the completeness of revascularization and intermediate-term outcomes of MICS with conventional sternotomy coronary artery bypass grafting (CABG). Two groups of 244 patients each receiving MICS-CABG and sternotomy-CABG between November 2015 and March 2019 were matched by propensity score matching. The completeness of revascularization and major adverse cardiovascular and cerebrovascular events (MACCE; a composite of death, myocardial infarction, stroke, or repeated target vessel revascularization) were compared between the groups. In the MICS-CABG group, the percentages of bypassed vessels 2, 3, and ≥4 were 53.7%, 36.1%, and 10.2%, respectively. Completeness of revascularization (95.5% vs 96.3%; P = .65) was comparable between MICS-CABG and sternotomy-CABG groups. Postprocedural angiography revealed an overall patency of 96.2% (578/601) for the MICS-CABG group. At 5 years, rates of MACCE (19.9% vs 22.1%; hazard ratio [HR], 0.80; 95% CI, 0.49-1.32; P = .39), death (10.6% vs 12.9%; HR, 0.87; 95% CI, 0.46-1.65; P = .67), myocardial infarction (5.6% vs 4.2%; HR, 0.82; 95% CI, 0.27-2.52; P = .73), stroke (6.7% vs 6.6%; HR, 1.11; 95% CI, 0.43-2.86; P = .83), and repeated target vessel revascularization (1.9% vs 1.8%; HR, 0.85; 95% CI, 0.17-3.15; P = .84) were similar between MICS-CABG and sternotomy-CABG. MICS-CABG, which appeared to yield noninferior completeness of revascularization and intermediate-term MACCE compared with sternotomy-CABG, could be an alternative for patients with multivessel coronary diseases.

Background: To evaluate the effect of minimally invasive direct coronary artery bypass (MIDCAB) simulator for cardiac residency training. Methods: A total of 26 resident surgeons who had never trained for coronary artery anastomosis participated in this training program. They received coronary artery anastomosis training on off-pump coronary artery bypass grafting (OPCAB) simulator for 15 h. After training, their performance of anastomosis was evaluated on the OPCAB simulator according to 12 items and a 5-point global rating scale. Based on the total score of assessment, those with an individual score of 12-36 formed group A, while group B was composed of the remaining trainees. The two groups then received another 15 h coronary artery anastomosis training on the MIDCAB simulator, and the performance was assessed. Results: Trainees improved their performance of coronary artery anastomosis after training on the OPCAB simulator. Group A was composed of 7 trainees with an individual with a total score of 12–36 points and group B was composed of the remaining 19 trainees. After MIDCAB simulator training, significant differences were noted in the pre- and post-training values in the A group (P < .001), and the assessment value of group A was significantly better than those of group B (P < .05). No significant difference was detected between pre- and post-training values in group B after MIDCAB simulator training (P > .05). Conclusion: We concluded that trainees who performed well in OPCAB simulation training can also perform better in MIDCAB, and our designed MIDCAB simulator was useful for residency training.

The study sought to explore the characteristics and outcomes of patients undergoing clinically indicated minimally invasive cardiac surgery—coronary artery bypass grafting (MICS-CABG) and off-pump coronary artery bypass for MICS-CABG eligible multivessel disease, to inform the design of a confirmatory comparative effectiveness trial. Over 30 months, 245 MICS-CABG and 158 off-pump coronary artery bypass participants were enrolled. Health-related quality-of-life was assessed using the 36-Item Short-Form Health Survey and Seattle Angina Questionnaire. The primary end point was the score on the physical component summary and mental component summary subscale of the 36-Item Short-Form Health Survey (on which scores range from 0 to 100, with higher scores indicating better health status). The score on the Physical Component Summary-United States subscale of the 36-Item Short-Form Health Survey increased to a greater extent with MICS-CABG than with off-pump coronary artery bypass at both 7 and 30 days (P = .002 and P = .001, respectively), as well as Physical Component Summary-Hong Kong subscale (MICS-CABG and off-pump coronary artery bypass: P = .002 and P < .001, respectively). The mental component summary subscale of the 36-Item Short-Form Health Survey in either the United States or Hong Kong and all 5 domains of Seattle Angina Questionnaire score were similar between the 2 groups throughout the follow-up period. MICS-CABG, an emerging modality for treating multivessel coronary disease, yields an improved 7- and 30-day physical function than off-pump coronary artery bypass. Moreover, both strategies resulted in similar significant relief from angina over 12 months. A randomized controlled trial is warranted to compare the efficacy of these 2 revascularization strategies. (Prospective Cohort Study on Minimal Invasive Coronary Surgery: NCT04267835).