Urgent isolated coronary artery bypass grafting: Del nido cardioplegia versus cold blood cardioplegia—A retrospective propensity-matched analysis

Aim: To compare myocardial protection and short-term clinical outcomes associated with Del Nido cardioplegia (DNC) versus cold blood cardioplegia (CBC) in patients undergoing urgent isolated coronary artery bypass grafting (CABG).

Materials and Methods: We retrospectively evaluated consecutive patients who underwent urgent isolated CABG at a single tertiary center between January 2018 and September 2020 (n=127). Propensity score matching was performed in a 1:1 ratio with a caliper width of 0.2 standard deviations (SD), yielding two well-balanced cohorts: DNC (n=64) and CBC (n=63). The primary endpoint was the change in serum troponin-I at 24 hours postoperativel. Secondary endpoints included changes in creatine kinase-MB (CK-MB), spontaneous return to sinus rhythm following reperfusion, vasoactive-inotropic score (VIS), intra-aortic balloon pump (IABP) requirement, and 30-day mortality. High-sensitivity troponin-I levels were measured at baseline and at 6, 12, and 24 hours postoperatively. Temporal biomarker trends were analyzed using linear mixed-effects models. Multivariable logistic regression with bootstrap validation was applied to identify predictors of absent spontaneous rhythm after reperfusion. Post-matching statistical power analyses were performed.

Results: The matched cohorts were well balanced across demographic, angiographic, and operative variables (all standardized mean differences <0.1). At 6 hours postoperatively, median delta troponin-I was 1102 ng/L (interquartile range [IQR] 820–1380) in the DNC group and 1094 ng/L (IQR 800–1320) in the CBC group. Mean delta CK-MB at 6 hours was 45±20 ng/mL for DNC and 48±22 ng/mL for CBC. Spontaneous rhythm recovery occurred more frequently with DNC (59.4% vs 20.6%). After adjustment for left ventricular ejection fraction (LVEF), aortic cross-clamp (ACC) time, and admission glucose level, DNC was associated with a lower likelihood of absent spontaneous rhythm (odds ratio 0.17;95% confidence interval 0.07–0.42). Total cardioplegia volume was significantly lower with DNC (1400±200 mL vs 1909.5±453.9 mL). VIS, prolonged inotrope use (>4 hours), IABP requirement, and 30-day mortality were comparable between groups.

Conclusion: In this propensity-matched analysis of urgent isolated CABG, DNC provided myocardial protection and early clinical outcomes comparable to CBC, while improving spontaneous rhythm recovery and reducing cardioplegia volume. These findings support clinical equipoise and inform the design of future randomized controlled trials.