Del Nido Microplegia Compared to Standard 1:4 Crystalloid Del Nido for Myocardial Protection

Editor’s Note:

We had a fun discussion with a couple of our surgeons today regarding the use of Del Nido cardioplegia.  At this institution we have been deploying the microplegia version of Del Nido, and subsequently substituting Blood as the crystalloid component, delivering the primary dose in 1,200 ml aliquots, and then redosing at 60 minutes (+/-).  To date it is the only institution I have been exposed to in terms of Del Nido delivery as a microplegic version of the typical 1:4 Blood to Crystalloid ratio that is more commonly used.  Comparatively speaking, the dosage amounts are the same (1200 mls), and the delivery of the the individual pharmacologic agents match up evenly, with the only difference being that in the 1:4 blood to crystalloid method, clearly there is a hemodilutional component that comes to bear.

At prior institutions, especially with smaller patients presenting with a lower preoperative hemoglobin, the obvious factors to be considered are an increased potential for blood transfusion, or employing  ultrafiltration to mitigate the hemodilutional impact of an additional aliquot of 900 ml’s of crystalloid, on the primary dose, and quite a bit more for subsequent dosing down the stretch.

So I thought I would throw down a couple of articles that articulate both sides of the discussion 🙂

Food for thought?  There have been a few instances where surgeons would try to connect the dots and correlate cardioplegia related perioperative vasoplegia events to the use of Del Nido.  Anecdotally it is hard to put that into perspective and draw a direct correlation to the use of Del Nido in these instances.  It should be noted as well, that in cases where are are prolonged instances of delivering continuous cardioplegia down SVG’s to help sustain myocardial perfusion, the end result is that the heart may receive quite a bit more of the cardioplegia constituents than we realize.  Typically, if you go past 2000 ml of Del Nido, I get worried.  As well, the other side of the coin where we find ourselves almost at the end of the 60 minute dosing window- we may keep stretching out the redosing schedule for that “extra 5 minutes” it takes to get that last stitch in- and NOT redose– which can also lead to a fatal myocardial insult.  75 minutes ends up becoming the tipping scale and becomes a dice game in terms of myocardial ischemia. It’s not pretty, and VAD’s don’t really help much.

Pump Strong!

Frank-

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Abstract

Objectives Few studies have evaluated the outcomes of whole blood microplegia in adult cardiac surgery. Our novel protocol includes removing the crystalloid portion and using the Quest Myocardial Protection System (MPS) for the delivery of del Nido additives in whole blood. This study sought to compare early and late clinical outcomes of whole blood del Nido microplegia (BDN) versus cold blood cardioplegia (CBC) following adult cardiac surgery.

Methods A total of 361 patients who underwent cardiac surgery using BDN were compared with a contemporaneous control group of 934 patients receiving CBC. Propensity matching yielded 289 BDN and 289 CBC patients. Chi-square analysis and Fisher’s exact test were performed to compare preoperative, operative, and postoperative characteristics on the matched data. Primary outcome was operative mortality, and secondary outcomes included clinical outcomes such as stroke, cardiac arrest, and intra-aortic balloon pump use. The Kaplan–Meier method was used to compare actuarial survival between the two groups using a log-rank test.

Results After matching, preoperative characteristics and surgery type were similar between groups. Cardioplegia type did not affect the primary end point of operative mortality. The rate of postoperative intra-aortic balloon pump was lower in BDN patients compared with CBC patients (0 vs. 2%; p = 0.01). There was no difference in late survival.

Conclusions Our novel protocol BDN was comparable with CBC, with similar clinical outcomes and no difference in operative mortality or actuarial survival. Further studies should evaluate the long-term outcomes of this technique.

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Abstract

Objective

Del Nido cardioplegia solution offers prolonged cardiac protection with single-dose administration; this is particularly interesting for aortic root surgery. However, there is a scarcity of data supporting its safety in adults undergoing complex cardiac surgery, such as aortic root repair. We hypothesized that del Nido cardioplegia solution and blood cardioplegia solution provide equivalent safety during aortic root surgery.

Methods

Between January 2015 and June 2018, 283 consecutive patients undergoing the Ross procedure (204) and valve-sparing operation (79) with del Nido cardioplegia solution or blood cardioplegia solution were 1:1 propensity matched (110 aortic root surgery), and outcomes were compared. Clinical patient characteristics and data were extracted from our local database for valve-sparing operations and for Ross procedures.

Results

Preoperative characteristics were similar between del Nido cardioplegia solution and blood cardioplegia solution after propensity matching (mean age, 48.6 ± 1.5 years). Median postoperative creatine kinase MB isotype did not differ between del Nido cardioplegia solution and blood cardioplegia solution (48.9 [14.9-300] μg/L vs 51.2 [12.4-116] μg/L for blood cardioplegia solution [ P = .1]), but there was a trend toward higher troponin T levels with del Nido cardioplegia solution (748 [221-5834] ng/L vs 710 [212-3332] ng/L for blood cardioplegia solution [ P = .07]). In patients with myocardial ischemia longer than 180 minutes, median creatine kinase MB isotype was higher in del Nido cardioplegia solution (75.1 [59.3-300] μg/L than in blood cardioplegia solution 60.5 [16.5-116] μg/L [ P = .01]). Aortic crossclamp and cardiopulmonary bypass times were shorter with del Nido cardioplegia solution (163 ± 5 vs 181 ± 5 minutes, P = .01 and 145 ± 4 vs 161 ± 4 minutes, respectively, P = .006). Return to spontaneous rhythm was more frequent in the del Nido cardioplegia solution group (52% [29/55] vs 27% [15/55], P = .006). There was no difference in inotropic or vasoactive agent use ( P = .8). Postoperative left ventricle ejection fraction was similar (0.54 ± 0.09 vs 0.55 ± 0.08 for del Nido cardioplegia solution and blood cardioplegia solution, respectively; P = .4). There was no difference between groups for perioperative mortality and postoperative complications.

Conclusions

Del Nido cardioplegia solution can be used as an alternative to blood cardioplegia solution in adults undergoing complex aortic root surgery, providing comparable clinical outcomes and improved surgical workflow. However, del Nido cardioplegia solution seems to be associated with increased myocardial injury, especially with extended myocardial ischemic times, but this finding did not translate into adverse clinical events. Caution is warranted in adopting this cardioplegic solution in aortic interventions requiring long ischemic times, and further study is required to establish its exact role in complex cardiac surgery.

The Academy Newsletter Spring 2017

Personal Clinical Experience With A Modified del Nido Cardioplegia Solution

Microplegia is a technique that consists of mixing blood from the cardiopulmonary bypass circuit with small quantities of concen-trated additives to arrest the heart and provide myocardial pro-tection from ischemia and reper-fusion. Large amounts of blood cardioplegia can be delivered with relatively minimal volumes of crystalloid being used. One of the major debates among clinicians is if blood cardioplegia is superior to crystalloid cardioplegia and how much blood is needed to opti-mized a technique. Currently, no major focus has been attempted in the study of using more blood in the del Nido cardioplegia solu-tion. In this study, this practice is achieved through the use of a Quest Medical MPS cardioplegia delivery system.

See Table 1

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Fifty patients undergoing valve surgeries were selected in the study. Inclusion criteria were age between 30-70 years and left ventricular ejection fraction great-er than 40%. Exclusion criteria were for CABG procedures or oth-er surgical procedure in addition to the planned valve surgery. Pa-tients were randomized to the modified del Nido solution or the traditional del Nido cardioplegia solution group (n = 25 each). The perfusionists either used the Quest Medical Myocardial Protection System (MPS) to deliver the modified del Nido or the Sorin Vanguard Cardioplegia System to deliver the traditional del Nido cardioplegia solution.

Overall, initial results demonstrate earlier extubation time by 2-3 hours (3.27 hours vs 5.74 hours), shorter length of ICU stay by 24-36 hours (58.32 hours vs 88.8 hours), and less hemodilution among patients undergoing cardiopulmonary bypass (5.8% vs 10.25%) among patients who re-ceived the modified del Nido cardioplegia solution. The P values for all three metrics measured were all statistically significant (P value <0.05). P values were calculated using the unpaired t test. In addition, in the modified del Nido solution group, none of the cases performed required blood transfusion and 4% of the cases performed required a hemoconcentrator. In the other group, 36% of the cases performed required blood transfusion and 76% of the cases performed required the use of a hemoconcentrator. However, a more accurate finding regarding blood transfusion rates and hemoconcentrator use can be further assessed with a larger sample size.
The full manuscript of this article has been submitted to the journal Perfusion for possible publication.