Type of Cardioplegia and Its Application May Not Explain Improvements in Cardiac Surgery Outcomes during the Last Two Decades

Background: Cardiac surgery has made tremendous achievements once cardiopulmonary bypass (CPB) was able to support circulation and cardioplegia was able to protect the arrested heart during the operative procedure. Continuous improvements made surgery better and safer until today, despite significant changes in today's patient profiles (i.e., advanced age, higher likelihood of comorbidities). With cardioplegic arrest being a key component of avoiding ischemic damage to the heart from the operative procedure, we aimed to assess the role of cardioplegia in most recent outcomes.

Method: A systematic literature search was performed for studies correlating specific cofactors with patient survival. We searched PubMed, SCOPUS, Embase, Cochrane Database, Google Scholar, and Ovid for the keywords “cardioplegia,” “myocardial protection,” “aortic cross-clamp time,” and “mortality.” Search terms were used as key words and in combination as Medical Subject Headings (MeSH) terms.

Results: Academic interest in cardioplegia declined in the past two decades. The number of publications in the time frames of 1990 to 2000 (n = 1,106) and 2010 to 2020 (n = 611) has been cut in half. The relative percentage of cardioplegia studies related to all cardiac surgical publications has been reduced to one-fifth (1.3–0.25%). The youngest cardioplegia solution has been introduced to the market 28 years ago (del Nido's); the oldest (Bretschneider's) had already been developed in the 1960s and 1970s. The search for duration of cardioplegic arrest times and mortality revealed a significant correlation with higher mortality at higher clamp-times, which was independent of cardioplegia type or delivery details. Age was qualified as a strong independent risk factor for mortality.

Conclusion: Given the results of this analysis, improved outcomes in cardiac surgery in the past two decades cannot be attributed to changes in our way to use cardioplegia. However, there is still a significant relationship between cardioplegic cross-clamp time and mortality making the field attractive for further investigations specifically for a changing and often older and sicker patient population.

Publication History

Article published online:
28 January 2023