Minimally invasive cardiac surgery (MICS) has become a popular approach due to its potential benefits, such as improved cosmesis, faster recovery, shorter hospital stays, and cost-effectiveness, compared with traditional median sternotomy. However, there have been some concerns regarding procedural efficiency and surgical outcomes, especially in the early phase of the learning curve of these procedures. In March 2025, a systematic review was conducted using MEDLINE, Embase, the Cochrane Library and Google Scholar databases to identify potential studies that quantitively assessed the learning curve in MICS using predefined metrics based on surgical times and/or clinical outcomes. There were 28 studies involving 13,257 patients that met the inclusion criteria, most of which were retrospective, focusing on 3 types of MICS: minimally invasive mitral valve surgery, aortic valve replacement, and coronary artery bypass grafting. The learning curve was assessed using arbitrary (split-group) and nonarbitrary (cumulative sum) methods. Common perioperative metrics included operative, cardiopulmonary bypass, aortic cross-clamp times, and postoperative complications. The reported number of cases needed to overcome the learning curve varied widely, ranging from 23 to 125 cases (mean, 39 cases [for repair] and 78 [for replacement]) for minimally invasive valve surgery, 40 to 138 cases (mean, 93 cases) for minimally invasive aortic valve replacement, and 16 to 100 cases (mean, 40 cases) for minimally invasive coronary artery bypass grafting. Differences in surgical process and postoperative outcomes suggest a learning curve in MICS, although stable morbidity and mortality rates indicate the safe adoption of these procedures with appropriate training. Nonetheless, significant heterogeneity across studies prevents precise learning curve characterization, highlighting the need for standardized, multivariable assessment frameworks.

Vaccine-induced immune thrombotic thrombocytopenia (VITT) has been reported in association with the coronavirus disease 2019 preventative adenovirus vector-based vaccines ChAdOx1 nCoV-19 (Oxford/AstraZeneca) and Ad26.COV2.S (Janssen/Johnson & Johnson) in hundreds of recipients across the globe. VITT is characterized by thrombosis, typically at unusual sites, low fibrinogen, and elevated plasma D-dimer, generally manifesting between 4 and 28 days following vaccination. Detection of anti-platelet factor antibodies using an enzyme-linked immunosorbent assay (ELISA) is often confirmatory. Although several similar principles subside in most diagnostic criteria for VITT, the presentation of a positive ELISA assay, use of expert hematology and neurology opinion, and exclusion of possible VITT cases outside the “standard” 4 to 28-day timeframe have contributed a lack of global standardization for defining VITT. Accordingly, the global and regional incidence of VITT differs according to the diagnostic pathway and case definition used. This has influenced the public perception of VITT's severity and the decision to use adenovirus vector-based vaccines for limiting severe acute respiratory syndrome coronavirus 2 infection. We hereby delineate the recognized pathogenic mechanisms, global incidence, discrepancies in diagnostic criteria, recommended treatments, and global implications to vaccine hesitancy from this coagulopathy.

Background: Reduced oxygen delivery (DO₂) during cardiopulmonary bypass (CPB) was proposed as a risk factor for the development of postoperative neurological complications (PONCs), including cerebrovascular accidents (CVA), delirium, and postoperative cognitive dysfunction (POCD). We aimed to review the current evidence on the association between intraoperative DO₂ and the incidence of PONCs. Methods: MEDLINE, Embase, the Cochrane Library, and Web of Science were electronically searched to identify comparative studies from inception until July 2023 that reported the association between intraoperative DO₂ levels and the incidence of PONCs (as defined by the scales and diagnostic tools utilized by the studies’ authors) in adults patients undergoing cardiac surgery using CPB. Results: Of the 2513 papers identified, 10 studies, including 21,875 participants, were included. Of these, three studies reported on delirium, two on POCD, and five on CVA. Eight studies reported reduced intraoperative DO₂ in patients who developed delirium and CVA. There was a lack of consensus on the cut-off of DO₂ levels or the correlation between the period below these threshold values and the development of PONC. Conclusions: Limited data suggest that maintaining intraoperative DO₂ above the critical threshold levels and ensuring adequate intraoperative cerebral perfusion may play a role in minimizing the incidence of neurological events in adult patients undergoing cardiac surgery on cardiopulmonary bypass.