Defining the Learning Curve in Minimally Invasive Cardiac Surgery: A Systematic Review and Meta-Analysis.

Area of Science:

• Cardiovascular Surgery
• Surgical Outcomes Research

Background:

• Minimally invasive cardiac surgery (MICS) offers benefits like better cosmesis and faster recovery over traditional sternotomy.
• Concerns exist regarding procedural efficiency and outcomes during the early learning curve of MICS.

Purpose of the Study:

• To systematically review and quantitatively assess the learning curve in minimally invasive cardiac surgery (MICS).
• To identify metrics and case numbers required to overcome the learning curve in MICS.

Main Methods:

• A systematic review of MEDLINE, Embase, Cochrane Library, and Google Scholar databases was conducted in March 2025.
• Studies quantitatively assessing MICS learning curves using surgical times and clinical outcomes were included.

Main Results:

• Twenty-eight studies (13,257 patients) analyzed mitral valve, aortic valve, and coronary artery bypass grafting.
• Learning curves varied widely (16-138 cases), with means of 39-78 for valve surgery and 40 for bypass grafting.
• Arbitrary and non-arbitrary methods assessed operative, bypass, cross-clamp times, and complications.

Conclusions:

• A learning curve exists in MICS, but stable morbidity/mortality suggests safe adoption with adequate training.
• Significant study heterogeneity hinders precise learning curve characterization.
• Standardized, multi-variable assessment frameworks are necessary for accurate MICS learning curve analysis.