Modified Pediatric Full Blood Cardioplegia Is Not Inferior to Classic Cold Crystalloid Cardioplegia in the Surgical Repair of Septal Defects

Background: Myocardial protection for longer aortic cross clamping periods is usually ensured with cardioplegia. The purpose of this retrospective study was to evaluate the feasibility and safety of tepid modified full blood cardioplegia (MBC) adapted to pediatric metabolism for surgical repair of simple septal defects compared with a standard cold crystalloid cardioplegia (CCC/Custodiol).

Methods: Observational clinical, hemodynamic and laboratory data of 64 retrospectively enrolled patients with simple septal defects (ASD, n = 34, VSD, n = 32) were matched according to diagnosis and body surface area. MBC (Calafiore cardioplegia enriched with electrolytes) was applied for 2 minutes and repeated every 20 minutes. CCC was given as a single shot and repeated every 60 minutes in longer clamping periods. Intraoperative hemodynamic evaluation of cardiac output and cardiac index was performed by aortic flow measurement before aortic cross clamping (T1), after bypass (T2) and after modified ultrafiltration (T3). Measurement of standard cardiac markers included Troponin-T (TnT) and CKMB at T1, T3 and first postoperative day (T4).

Results: Patient pairs did not statistically differ in aortic cross clamping time and bypass time. There was no operative mortality. At given observation points cardiac index and cardiac markers did not differ between groups.

Table 1

		MBC	CCC	p-Value
T1	Trop T (ng/mL)	0.013 (0.01–0.05)	0.021 (0.01–0.11)	0.142
	CKMB (μg/L)	3.5 (1.9–13.0)	5.2 (1.9–13.0)	0.952
	CI (L/min/m2)	2.8 (1.39–4.15)	2.6 (1.44–2.53)	0.279
T2	CI (L/min/m2)	3.4 (1.77–5.39)	2.9 (1.23–5.19)	0.949
T3	Trop T (ng/ mL)	3.2 (0.34–18)	4.2 (0.03–25)	0.152
	CKMB (μg/L)	144.6 (31–415)	167.9 (8.7–455)	0.642
	CI (L/min/m2)	3.4 (1.62–5.4)	3.3 (1.84–5.58)	0.854
T4	Trop T (ng/ mL)	0.9 (0.25–2.8)	1.23 (0.27–3.0)	0.172
	CKMB (μg/L)	51.5 (5–100)	62.2 (28–140)	0.751

Conclusion: This study indicates that tepid MBC preserves myocardial function as good as CCC during aortic cross-clamping in the context of corrective pediatric heart surgery for simple septal defects. Further studies are needed to evaluate possible beneficial effects of modified pediatric blood cardioplegia for larger patient groups.