Cold crystalloid versus warm blood cardioplegia in patients undergoing aortic valve replacement

Perceval sutureless bioprosthesis versus Trifecta sutured bioprosthesis for aortic valve replacement: immediate results of the Perfecta study

Introduction

The Perceval sutureless biological prosthesis for aortic valve replacement has been introduced with the rationale for shortening surgical, extracorporeal circulation and aortic cross-clamping times, in order to reduce postoperative complications.

Aim

To evaluate early hemodynamic performance and immediate outcomes of implantation of the Perceval sutureless bioprosthesis in comparison with the St. Jude Trifecta sutured bioprosthesis for aortic valve replacement (Perfecta study).

Material and methods

Between December 2014 and June 2023, 281 patients underwent St. Jude Trifecta implantation (n = 220, mean age: 75.2 ±6.5 years) and Perceval implantation, when indicated (n = 61, mean age: 77.9 ±5.1 years). Concomitant CABG was performed in 73 (33%) and in 27 (44%) patients, respectively.

Results

Extracorporeal circulation and cross-clamp times were significantly shorter in Perceval patients in all aortic valve replacements (61 ±23 and 49 ±18 minutes vs. 96 ±36 and 67 ±21 minutes), and in isolated procedures (54 ±10 and 43 ±8 minutes vs. 84 ±28 and 66 ±21 minutes) (p < 0.0001, for all comparisons). Operative mortality was absent and 2.7%, respectively (p = 0.2). Postoperatively, low output cardiac syndrome (0% vs. 4.5%) and total rate of major cardiac and non-cardiac related complications (6.6% vs. 18.6%) were significantly lower in Perceval patients (p = 0.01). Echocardiography at discharge in comparison with preoperatively showed a relevant and similar decrease of mean and peak trans-aortic valve gradients for the Trifecta prosthesis (11.6 ±4.3 vs. 50 ±15.2 mm Hg; 21.6 ±7.3 vs. 78.8 ±24 mm Hg) and for the Perceval prosthesis (12.6 ±4.8 vs. 52 ±12.5 mm Hg; 22.6 ±7.9 vs. 77.8 ±16 mm Hg) (p < 0.00001, for all comparisons). Better global cardiac function was observed in Perceval patients. Concomitant multi-vessel and left main coronary artery disease (p = 0.046; HR = 4.6) and chronic pulmonary disease (p = 0.006; HR = 5.6) were detected as independent predictors of death and postoperative major complications.

Conclusions

Early hemodynamic performance appears to be satisfactory with the use of Trifecta sutured and Perceval sutureless bioprostheses. Perceval implantation allows reduction of surgical times, better preservation of myocardial contractile function and, consequently, reduction of the risk of postoperative complications.

Novel Strategies to Improve the Cardioprotective Effects of Cardioplegia

The use of cardioprotective strategies as adjuvants of cardioplegic solutions has become an ideal alternative for the improvement of post-surgery heart recovery. The choice of the optimal cardioplegia, as well as its distribution mechanism, remains controversial in the field of cardiovascular surgery. There is still a need to search for new and better cardioprotective methods during cardioplegic procedures. New techniques for the management of cardiovascular complications during cardioplegia have evolved with new alternatives and additives, and each new strategy provides a tool to neutralize the damage after ischemia/reperfusion events. Researchers and clinicians have committed themselves to studying the effect of new strategies and adjuvant components with the potential to improve the cardioprotective effect of cardioplegic solutions in preventing myocardial ischemia/reperfusion-induced injury during cardiac surgery. The aim of this review is to explore the different types of cardioplegia, their protection mechanisms, and which strategies have been proposed to enhance the function of these solutions in hearts exposed to cardiovascular pathologies that require surgical alternatives for their corrective progression.

Do we correctly calculate doses of cardioplegia during aortic valve replacement procedures? A preliminary report

Introduction

Intraoperative myocardial protection during aortic valve replacement (AVR) for aortic stenosis (AS) is of paramount importance for outcomes. The dose of cardioplegia is usually calculated with reference to body mass.

Aim

To assess whether such a strategy should be applied to all AS patients undergoing AVR.

Material and methods

The study included 94 patients who underwent elective isolated AVR in cardiopulmonary bypass with cold cardioplegic arrest, with a mean age of 65.4 ±7.8 years. They were divided into two subgroup: A with an infusion of high (above median) and subgroup B with a low (below median) volume of cardioplegia indexed for left ventricular mass (LVM). Their doses were referred to the maximal postoperative release of cardiac troponin I (cTnI max). Eventually, it was examined whether the extent of intraoperative myocardial injury translated into long-term survival stratified according to the Kaplan-Meier method.

Results

The mean volume of cardioplegia was 1381 ±279 ml (4.9 ±1.6 ml/g of LV myocardium). cTnI max was much higher in group A than in group B (medians: 14.918 vs. 9.876 μg/l; p = 0.005). Moreover, a negative correlation between the index cardioplegia volume and cTnI max (r = 0.345) was noted. The five-year probability of survival in subgroup A (95.7%) was significantly better than that in subgroup B individuals (82.6%, p = 0.044).

Conclusions

Calculating cardioplegic doses during AVR solely based on body mass may be suboptimal and have a significant impact on postoperative outcomes.

Bentall Operation: Early Surgical Results, Seven-Year Outcomes, and Risk Factors Analysis

Aim: To analyze early and mid-term outcomes of the Bentall operation. Methods: Two hundred and seventeen patients (mean age 65.6 ± 15.9 years, males/females 172/45) underwent Bentall operation in a 7-year period (January 2015−December 2021), on average, 30 Bentall operations occurred per year, using biological (n = 104) or mechanical (n = 113) valved conduits for the treatment of ascending aorta−aortic root aneurysms. Associate procedures were performed in 58 patients (26.7%); coronary artery bypass grafting (CABG) in 35 (16%). Mean follow-up was 55.2 ± 24 (median 60.2) months. Cox model analysis was used to assess risk factors, Kaplan−Meier and log-rank tests were used to assess different survival rates. Results: Operative mortality was 1.38%. At 7 years, survival, freedom from cardiac death, and event-free survival were 93% ± 2%, 99% ± 1%, and 81% ± 5%. NYHA class (p < 0.0001), trans-aortic valve mean (p < 0.0001) and maximum (p < 0.000) gradients, left ventricular hypertrophy (p < 0.05), and pulmonary arterial pressure (p = 0.002) significantly improved vs. preoperative values. Concomitant CABG during Bentall operation independently affected late outcomes (HR 1.9−2.3; p-values < 0.05). Late survival was affected by concomitant CABG (84% ± 8% vs. 95% ± 2%, p = 0.04), preoperative myocardial infarction (91% ± 9% vs. 97% ± 2%, p = 0.02), and biological vs. mechanical prostheses valved conduits (91% ± 9% vs. 95% ± 3%, p = 0.02). Event-free survival also was affected by concomitant CABG (62% ± 14% vs. 85% ± 5%, p = 0.005) and biological prostheses (78% ± 8% vs. 84% ± 6%, p = 0.06). Freedom from endocarditis−redo operation was 83% ± 9% for biological prostheses vs. 89% ± 6% for mechanical prostheses (p = 0.49). Conclusions: Low rates of operative mortality and late complications make Bentall operation the gold standard for the treatment of ascending aorta−aortic root aneurysms. Coronary ischemic disease affects late outcomes. Biological prostheses should be preferred for the elderly.

N-Terminal of the Prohormone Brain Natriuretic Peptide Predicts Postoperative Cardiogenic Shock Requiring Extracorporeal Membrane Oxygenation

Aims: Heart valve surgery is associated with a risk of serious postoperative complications including postoperative cardiogenic shock (described as postcardiotomy shock (PCS)). The indication for extracorporeal membrane oxygenation (ECMO) is cardiogenic shock, which is resistant to optimal causal and pharmacological treatment, including the supply of catecholamines and/or an intra-aortic balloon pump (IABP). The aim of this study was to assess the usefulness of the selected preoperative biomarkers in the prediction of postoperative cardiogenic shock requiring ECMO in patients undergoing heart valve surgery. Methods: A prospective study was conducted on a group of consecutive patients with significant valvular heart disease that underwent elective valve surgery. The primary endpoint at the intra-hospital follow-up was postoperative cardiogenic shock requiring ECMO. Univariate analysis, followed by multivariate regression analysis, were performed. Results: The study included 610 patients. The primary endpoint occurred in 15 patients. At multivariate analysis, the preoperative N-terminal of the prohormone brain natriuretic peptide (NT-proBNP) level (OR 1.022; 95% CI 1.011–1.034; p = 0.001) remained an independent predictor of the primary endpoint. Conclusions: An elevated NT-proBNP level was associated with a higher risk of postoperative cardiogenic shock requiring the use of ECMO.

Initial Surgical Strategy for the Treatment of Type A Acute Aortic Dissection: Does Proximal or Distal Extension of the Aortic Resection Influence the Outcomes?

(1) Background: We sought to analyze and compare the outcomes in terms of early and late mortality and freedom from a redo operation in patients undergoing surgical treatment for a type A acute aortic dissection in relation to the initial surgical treatment strategy, i.e., proximal or distal extension of the aortic segment resection, compared with isolated resection of the supracoronary ascending aorta. (2) Methods: This is a retrospective study in which we included 269 patients who underwent operations for a type A acute aortic dissection in the Department of Cardiac Surgery of Tor Vergata University from May 2006 to May 2016. The patients were grouped according to the extent of the performed surgical treatment: isolated replacement of the supracoronary ascending aorta (NE, no extension), replacement of the aortic root (PE, proximal extension), replacement of the aortic arch (DE, distal extension), and both (BE, bilateral extension). The analyzed variables were in-hospital mortality, postoperative complications (incidence of neurological damage, renal failure and need for prolonged intubation), late mortality and need for a redo operation. (3) Results: Unilateral cerebral perfusion was performed in 49.3% of the patients, and bilateral perfusion—in 50.6%. The overall in-hospital mortality was 31.97%. In the multivariate analysis, advanced age, cardiopulmonary bypass time and preoperative orotracheal intubation were independent predictors of in-hospital mortality. In the population of patients who survived the surgery, the probability of survival at 92 months was 70 ± 5%, the probability of freedom from a redo operation was 71.5 ± 5%, the probability of freedom from the combined end-point death and a redo operation was 50 ± 5%. The re-intervention rate in the general population was 16.9%. The overall probability of freedom from re-intervention was higher in patients undergoing aortic root replacement, although not reaching a level of statistical significance. Patients who underwent aortic arch treatment showed reduced survival. (4) Conclusions: In the treatment of type A acute aortic dissection, all the surgical strategies adopted were associated with satisfactory long-term survival. In the group of patients in which the aortic root had not been replaced, we observed reduced event-free survival.

A Cardioplegic Solution with an Understanding of a Cardiochannelopathy

Cardiac surgeries have been improved by accompanying developing cardioplegia solutions. However, the cardioplegia application presents an ongoing challenge with a view of a sufficiently restored cardiac function. In this review, we focus on the cardioplegia-induced mechanism and summarize the findings of studies undertaken to improve cardioprotective strategies. Currently, and somewhat surprisingly, relatively little is known about cardiac electrolyte regulation through channel physiology. We hope that an improved understanding of the electrolyte transport through ion channels/transporters and modulations of water channel aquaporins will provide an insight into cardiac channel physiology and a channel-based cardiac pathology of a cardiochannelopathy.

Warm versus cold cardioplegia in cardiac surgery: A meta-analysis with trial sequential analysis

Objective

This meta-analysis aimed to compare clinical outcomes of warm and cold cardioplegia in cardiac surgeries in adult patients, with trial sequential analysis (TSA) used to determine the conclusiveness of the results.

Methods

Electronic searches were performed on PubMed, Medline, Scopus, EMBASE, and Cochrane library to identify all studies that compared warm and cold cardioplegia in cardiac surgeries. Primary end points were in-hospital or 30-day mortality, myocardial infarction, low cardiac output syndrome, intra-aortic balloon pump use, stroke, and new atrial fibrillation. Secondary end points were acute kidney injury, hospital length of stay, and intensive care unit length of stay. Prespecified subgroup analyses were performed for (1) studies published since publication of Fan and colleagues in 2010, (2) randomized controlled studies, (3) studies with low risk of bias, (4) coronary artery bypass graft surgeries, and (5) studies with cold blood versus those with cold crystalloid cardioplegia. TSA was performed to determine conclusiveness of the results, using on all outcomes without significant heterogeneity from studies of low risk of bias.

Results

No significant differences were found between post-operative rates of mortality, myocardial infarction, low cardiac output syndrome, intra-aortic balloon pump use, stroke, new atrial fibrillation, and acute kidney injury between warm and cold cardioplegia. TSA concluded that current evidence was sufficient to rule out a 20% relative risk reduction in these outcomes.

Conclusions

Concerning safety outcomes, current evidence suggests that the choice between warm and cold cardioplegia remains in the surgeon's preference.

Single-Dose Del Nido Cardioplegia vs. Blood Cardioplegia in Aortic Valve Replacement Surgery

INTRODUCTION

In this study, we aimed to compare Del Nido cardioplegia (DNC) with blood cardioplegia (BC) in aortic valve replacement.

METHODS

A two-year single-institute retrospective cohort study was accomplished. Subjects who underwent aortic valve replacement surgery were divided into two groups (DNC and BC) and outcomes were compared.

RESULTS

Preoperative demographics and clinical data of the patients in both groups were similar. The time until cardiac arrest following administration of the first dose of cardioplegia was statistically significantly shorter in the BC group (47.0 sec. 25-103) than in the DNC group (63.0 sec. 48-140) (P=0.012). Cross-clamping time was longer in the BC group (48.7±12.3 min. vs. 41.5±11.8 min.) (P=0.041). Cardiopulmonary bypass time was statistically significantly shorter in the DNC group (BC 60.8±18.5 min., DNC 53.7±15.2 min.) (P=0.046). The rate of postoperative use of intravenous positive inotropic support drugs (dopamine, dobutamine, norepinephrine, etc.) for more than two hours was significantly higher in the BC group (20 [23.5%] in the BC group and nine [17.3%] in the DNC group) (P=0.035). Creatine kinase myocardial band and troponin I levels were slightly lower in patients receiving DNC, but no statistically significant difference was detected.

CONCLUSION

Del Nido cardioplegia is safe and can be used efficiently as an alternative to blood cardioplegia in isolated aortic valve replacement surgery.

Warm Blood Cardioplegia for Myocardial Protection: Concepts and Controversies

Warm blood cardioplegia has been an established cardioplegic method since the 1990s, yet it remains controversial in regard to myocardial protection. This review will describe the physiologic and technical concepts behind warm blood cardioplegia, as well as outline the current basic and clinical research that evaluates its usefulness. Controversies regarding this technique will also be reviewed. A long history of experimental data indicates that warm blood cardioplegia is safe and effective and thus suitable myocardial protection during cardiopulmonary bypass surgeries.

Enhanced Activity by NKCC1 and Slc26a6 Mediates Acidic pH and Cl- Movement after Cardioplegia-Induced Arrest of db/db Diabetic Heart

Diabetic heart dysfunctions during cardiac surgeries have revealed several clinical problems associated with ion imbalance. However, the mechanism of ion imbalance mediated by cardioplegia and a diabetic heart is largely unclear. We hypothesized that ion transporters might be regulated differently in the diabetic heart and that the differentially regulated ion transporters may involve in ion imbalance of the diabetic heart after cardioplegic arrest. In this study, we modified the Langendorff-free cardioplegia method and identified the involved ion transporters after cardioplegia-induced arrest between wild type and db/db heart. Enhanced expression of Na⁺-K⁺-2Cl⁻ cotransporter 1 (NKCC1) was observed in the db/db heart compared to the wild type heart. Enhanced NKCC1 activity was observed in the left ventricle of db/db mice compared to that of wild type after cardioplegia-induced arrest. The expression and activity of Slc26a6, a dominant Cl⁻/HCO₃⁻ exchanger in cardiac tissues, were enhanced in left ventricle strips of db/db mice compared to that of wild type. The Cl⁻ transporting activity in left ventricle strips of db/db mice was dramatically increased as compared to that of wild type. Interestingly, expression of Slc26a6, as well as carbonic anhydrase IV as a supportive enzyme of Slc26a6, was increased in db/db cardiac strips compared to wild type cardiac strips. Thus, the enhanced Cl⁻ transporting activity and expression by NKCC1 and Slc26a6 in db/db cardiac tissues after cardioplegia-induced arrest provide greater insight into enhanced acidosis and Cl⁻ movement-mediated db/db heart dysfunction. Thus, we suggested that enhanced Cl⁻ influx and HCO₃⁻ efflux through NKCC1 and Slc26a6 offer more acidic circumstances in the diabetic heart after cardioplegic arrest. These transporters should be considered as potential therapeutic targets to develop the next generation of cardioplegia solution for protection against ischemia-reperfusion injury in diabetic hearts.