Equivalent myocardial protection and clinical outcomes have been demonstrated with the use of del Nido (DC) when compared to blood cardioplegia (BC) in adult isolated CABG and valve patients. However, its safety and efficacy in cardiac procedures with aortic cross-clamp times greater than 90 minutes is still unknown.
From 5/2014 to 9/2019, 2,506 adult patients at our center underwent cardiac surgery requiring prolonged aortic cross-clamp time defined as 90 minutes or longer. Myocardial protection was achieved with blood cardioplegia in 1,955 patients and del Nido cardioplegia in 551 patients. Two surgeons used del Nido exclusively and five used blood exclusively over the study period. Blood cardioplegia was delivered anterograde and retrograde while del Nido was delivered anterograde only. Propensity matching of several pre-operative characteristics, including primary cardiac pathology, yielded 526 well-matched pairs. Emergency and re-operative cases were included. Troponin T levels were drawn at 12 hours post-op in all patients. Clinical data were extracted from our local STS database. Subgroup analyses were performed based on cross-clamp time stratification.
For the propensity-matched cohort, the median cross-clamp time was longer in blood compared to del Nido cardioplegia (114 [100-145] (DC) min vs 153 [122-200] (BC) min, p<0.0001) while intra-operative peak glucose was higher with blood cardioplegia (173 [147-200]g/dl (DC) vs 197 [171-228]g/dl (BC), p<0.001). In addition, peri-operative mortality (3.4% vs 3.0%, p=0.7273), stroke (3.2% vs 2.1%, p=0.2504), renal failure (6.5% vs 4.6%, p=0.1767), atrial fibrillation (34% vs 31.4%, p=0.3575), intra-aortic balloon pump use (5.3% vs 4.6%, p=0.5694), and extra corporeal membrane oxygenation use (3.0% vs 2.9%, p=0.8596) did not differ between del Nido and blood cardioplegia. Post-op troponin T levels were 0.53 [0.30-0.96 ng/ml and] 0.62 [0.38-1.07] ng/ml for del Nido and blood, respectively (p=0.0024). Subgroup analysis revealed higher troponin T levels with del Nido for cross-clamp times between 150 and 180 minutes. One-, two-, and five-year survival rates were 93.3%, 91.1%, and 78.7% for del Nido and 94.5%, 91.8%, and 81.5% for blood, respectively and did not differ significantly (p=0.5140).
In adult cardiac surgical procedures with aortic cross-clamp times greater than 90 minutes, comparable myocardial protection, peri-operative mortality and morbidity, and distant survival were observed with the use of del Nido compared to blood cardioplegia. Higher troponin levels were seen in del Nido patients with cross-clamp times between 150 and 180 minutes, but this was not associated with increased mortality.