Neurocognitive Functions after Beating Heart Mitral Valve Replacement without Cross-Clamping the Aorta

Decreased brain-derived neurotrophic factor levels may predict early perioperative neurocognitive disorder in patients undergoing coronary artery bypass surgery: A prospective observational pilot study

STUDY OBJECTIVE

To determine the prognostic value of the change in intraoperative BDNF (Brain-derived neurotrophic factor) levels during cardiac surgery with cardiopulmonary bypass (CPB) on early perioperative neurocognitive disorder (PND).

DESIGN

Prospective observational pilot study.

SETTING

The study was performed in the Medical Faculty Hospital, from January 2020 to August 2020.

PATIENTS

45 adult patients undergoing elective coronary artery bypass surgery (CABG) with CPB.

INTERVENTIONS

None.

MEASUREMENTS

Cognitive function was evaluated 1 day before and 4 days after the surgery. Serum BDNF levels were measured at four time points (T1: after induction; T2: with aortic cross-clamp; T3: without aortic cross-clamp; T4: 4 days after surgery) by enzyme-linked immunosorbent assay.

MAIN RESULTS

The incidence of PND was 37.8% four days after surgery. Serum BDNF (T2 and T4) levels were significantly lower in PND group compared to non- PND group (p = 0.003 and p = 0.016, respectively). Moreover, lactate, rSO₂ (regional cerebral oxygen saturation), aortic cross-clamp time, CPB duration, and the amount of blood transfusion differed between the groups. Logistic regression analysis identified serum BDNF-T2, age, cross-clamp time, and rSO₂-T2 as independent risk factors for PND. Based on the ROC analysis, the area under curve (AUC) of BDNF-T2 concentration for prediction of PND was 0.759 with sensitivity of 71.4% and specificity of 64.7% (p < 0.01).

CONCLUSION

Intraoperative BDNF serum levels may be a useful biomarker in predicting PND in patients undergoing CABG surgery. More comprehensive studies is needed in order to confirm the effect of decreasing intraoperative BDNF serum levels on the development of PND.

TRIAL REGISTRATION NUMBER

NCT04250935 www.clinicaltrials.gov.

Cognitive Outcomes After Heart Valve Surgery: A Systematic Review and Meta-Analysis

OBJECTIVES

To summarize evidence on cognitive outcomes after heart valve surgery; secondary aim, to examine whether aortic and mitral valve surgery are associated with different cognitive outcomes.

DESIGN

Preferred Reporting Items for Systematic Reviews and Meta-Analyses systematic review and meta-analysis.

SETTING

Cardiac surgery.

PARTICIPANTS

Individuals undergoing heart valve surgery.

MEASUREMENTS

We searched MEDLINE, EMBASE, and PsycINFO for peer-reviewed reports of individuals undergoing heart valve surgery who underwent pre- and postoperative cognitive assessment. Our initial search returned 1,475 articles, of which 12 were included. Postoperative cognitive results were divided into those from 1 week to 1 month (early outcomes, n_pooled  = 450) and from 2 to 6 months (intermediate outcomes; n_pooled  = 722). No studies with longer-term outcomes were identified.

RESULTS

Subjects had moderate early cognitive decline from baseline (Becker mean gain effect size (ES)=-0.39 ± 0.27) that improved slightly by 2 to 6 months (ES=-0.25 ± 0.38). Individuals undergoing aortic valve surgery-who were older on average than those undergoing mitral valve surgery (68 vs 57)-had greater early cognitive decline than those undergoing mitral valve surgery (ES=-0.68 vs -0.12), but both cohorts had similar decline 2 to 6 months postoperatively (ES=-0.27 vs -0.20).

CONCLUSIONS

Heart valve surgery is associated with cognitive decline over the 6 months after surgery, but outcomes beyond 6 months are unclear. These findings highlight the cognitive vulnerability of this population, especially older adults with aortic stenosis. © 2018 American Geriatrics Society and Wiley Periodicals, Inc. J Am Geriatr Soc 66:2327-2334, 2018.

Comparison of neurocognitive functions after beating-heart mitral valve replacement without aorta cross-clamping and after standard mitral valve replacement with cardioplegic arrest

BACKGROUND

The aim of this study was to compare the postoperative long-term neurocognitive functions of patients who under-went beating-heart mitral valve replacement on cardiopulmonary bypass (CPB) without aorta cross-clamping with those of patients who underwent mitral valve replacement via the classic method.

METHODS

The study group included 25 randomly selected patients who underwent beating-heart mitral valve surgery. During the same period, 25 patients were randomly selected as controls to undergo mitral valve replacement procedures via the standard ascending aorta-cannulation technique. The clinical and postoperative (2 months) neurocognitive functional data of both groups were compared.

RESULTS

Neurologic deficit was observed in neither group during the postoperative period. There were no statistically significant differences between the control and the study groups with respect to Hospital Anxiety and Depression Scale (HADS) results (HADS: anxiety, P = .653; HADS: depression, P = .225), in the right hemispheric cognitive function test results (Raven's Standard Progressive Matrices [RSPM] and Line Orientation Test [LOT] tests: RSPM, P = .189), and in the left hemispheric cognitive function test results (the Ray Auditory Verbal Learning [RAVL] and Stroop Color-Word Test [SCWT] tests: SCWT 1 time, P = .300; SCWT 2 time, P = .679; SCWT 3 time, P = .336; SCWT 4 time, P = .852; SCWT 5 time, P = .416; RAVL total verbal learning, P = .167; RAVL immediate recall, P = .791; RAVL distraction trial, P = .199; RAVL retention, P = .174; RAVL delayed recall, P = .111; RAVL recognition, P = .282; SCWT 4 mistake, P = .306; SCWT 4 reform, P = .066; SCWT 5 mistake, P = .236; SCWT 5 reform, P = .301).

CONCLUSIONS

The technique of mitral valve replacement with normothermic CPB without cross-clamping of the aorta may be safely used for the majority of patients requiring mitral valve replacement without causing deterioration in neurocognitive functions.

Beating heart continuous coronary perfusion for valve surgery: what next for clinical trials?

Prior to the introduction of cardioplegia, beating heart continuous coronary perfusion (BHCCP) was the only available method of myocardial protection. Currently, cardiac surgery on cardiopulmonary bypass with cardioplegic arrest is the gold standard strategy. Cardioplegic arrest provides an easier and safer way to operate on a still heart. It enables the performance of a broader range of cardiac procedures, and avoids the potential difficulties of continuous perfusion on a beating heart. Despite the overall effectiveness and safety of cardioplegia, some adverse effects remain, mainly due to the insult of ischemia, which results in ischemic reperfusion injury. As a result BHCCP has seen a revival as an alternative to cardioplegia for performing complex valvular surgery. Increasing experience reporting safety and efficacy of BHCCP is being published. However, despite the reported advantages, current available evidence validating safety and efficacy of BHCCP is controversial. This article provides an overview of BHCCP highlighting the current best available evidence supporting this strategy, concerns, controversies and potential areas for further research.

Beating-Heart Valve Surgery: A Systematic Review

Beating-heart continuous coronary perfusion (BHCCP) has been promoted as an alternative to the technique of cardioplegic arrest in valve surgery. Its potential advantage is the elimination of cardioplegia and the corollary risk of ischemic reperfusion injury. The use of CCP has been recommended especially when performing more complex operations, such as mitral valve repair, and particularly as surgeons become more familiar with beating-heart coronary surgery. We conducted a systematic review to assess the strength of the evidence supporting the efficacy of BHCCP compared to cardioplegia in valve surgery. Thirty nine reports were identified. Of these, only two were randomized control trials. Overall the studies were generally of poor quality and had a low evidence level. In those studies, mortality and major morbidity from BHCCP were within acceptable levels, nevertheless, there was no advantage over cardioplegic arrest. On the other hand there is weak evidence that it may reduce functional and biochemical markers of myocardial injury. In conclusion, BHCCP is an operative strategy in valve surgery with some potential benefits. There is, however a need for a high quality, prospective, randomized control trial to establish the exact role for BHCCP in complex valve surgery.