Atrial Fibrillation Ablation Using Robotic Magnetic Navigation Reduces the Incidence of Silent Cerebral Embolism

Background: The incidence of silent cerebral embolisms (SCEs) has been documented after pulmonary vein isolation using different ablation technologies; however, it is unreported in patients undergoing with atrial fibrillation (AF) ablation using Robotic Magnetic Navigation (RMN). The purpose of this prospective study was to investigate the incidence, risk predictors and probable mechanisms of SCEs in patients with AF ablation and the potential impact of RMN on SCE rates.Methods and Results: We performed a prospective study of 166 patients with paroxysmal or persistent AF who underwent pulmonary vein isolation. Patients were divided into RMN group (n = 104) and manual control (MC) group (n = 62), and analyzed for their demographic, medical, echocardiographic, and risk predictors of SCEs. All patients underwent cerebral magnetic resonance imaging within 48 h before and after the ablation procedure to assess cerebral embolism. The incidence and potential risk factors of SCEs were compared between the two groups. There were 26 total cases of SCEs in this study, including 6 cases in the RMN group and 20 cases in the MC group. The incidences of SCEs in the RMN group and the MC group were 5.77 and 32.26%, respectively (X2 = 20.63 P < 0.05). Univariate logistic regression analysis demonstrated that ablation technology, CHA2DS2-VASc score, history of cerebrovascular accident/transient ischemic attack, and low ejection fraction were significantly associated with SCEs, and multivariate logistic regression analysis showed that MC ablation was the only independent risk factor of SCEs after an AF ablation procedure.Conclusions: Ablation technology, CHA2DS2-VASc score, history of cerebrovascular accident/transient ischemic attack, and low ejection fraction are associated with SCEs. However, ablation technology is the only independent risk factor of SCEs and RMN can significantly reduce the incidence of SCEs resulting from AF ablation.Clinical Trial Registration: ChiCTR2100046505.

Del Nido versus warm blood cardioplegia in adult patients with a low ejection fraction

Background Del Nido cardioplegia was recently introduced to adult cardiac surgery with encouraging results. The effect of Del Nido cardioplegia in patients with low ejection fraction (EF) has not been thoroughly evaluated. The objective of this study was to assess the safety of Del Nido cardioplegia in adult patients with low EF compared to intermittent warm blood cardioplegia. Results During 2018 and 2019, 73 adult patients with an EF of ≤ 40% underwent cardiac surgery using Del Nido cardioplegia. The patients were compared to a historical cohort of consecutive patients with low EF who had intermitted warm blood cardioplegia (n = 81). Patients who had Del Nido cardioplegia had significantly lower EuroSCORE II (2.73 (1.7–4.1) vs. 4.5 (2.4–7.4), P = 0.004). There were no differences in creatinine clearance and preoperative echocardiographic data between the groups. Cardiopulmonary bypass and cross-clamp times were non-significantly lower with Del Nido cardioplegia. There were no differences in stroke and postoperative echocardiographic data between the groups. No hospital mortality was reported in both groups. Peak troponin levels were significantly higher in patients who had Del Nido cardioplegia (0.88 (0.58–1.47) vs. 0.7 (0.44–1.01) ng/dL; P = 0.01); however, after multivariable regression analysis, cardiopulmonary bypass time was the only predictor of postoperative troponin level (coefficient 0.005 (95% CI: 0.003–0.008); P < 0.001). ICU stay was significantly longer in patients who had Del Nido cardioplegia (4 (3–6) vs. 2(1–4) days, P < 0.001), while postoperative hospital stay did not differ between the groups. After multivariable regression, the use of intermittent warm blood cardioplegia was significantly associated with shorter ICU stay (coefficient − 1.80 (95% CI − 3.06 – -0.55); P = 0.01). Conclusions Prolonged ICU was reported with Del Nido cardioplegia; however, there were no differences in the duration of hospital stay and the clinical outcomes between the groups. Despite the proven efficacy of intermittent warm blood cardioplegia, the use of Del Nido cardioplegia might be safe in patients with low EF.

The effects of levosimendan on renal functions in open-heart surgery patients with a low ejection fraction

Purpose. This study investigated the effects of levosimendan on renal functions in patients with a preoperative low ejection fraction undergoing open-heart surgery and cardiopulmonary bypass (CPB). Materials and Methods. The study retrospectively evaluated 64 patients with a diagnosis of mitral valve insufficiency and left ventricular dysfunction undergoing open-heart surgery with CPB. Patients were divided depending on the preoperative blood creatinine level less (Group 1) or more than 1.2 mg/dL (Group 2). A bolus dose of levosimendan was administered through the aortic arch at the end of the CPB, preceding an infusion of levosimendan intravenously in all patients. Demographic data, preoperative and 48-hour postoperative echocardiographic studies were done. The blood urea and creatinine levels were collected preoperatively and on postoperative days 1, 3, and 10. The use of inotropic support, intra-aortic balloon pump, and complications were recorded. Results. The demographic data were similar between groups (p>0.05). Preoperative serum creatinine levels were higher in Group 1 in comparison to Group 2 (p=0.01, p<0.001, respectively). The aortic cross-clamp and cardiopulmonary bypass times were similar between groups (p>0.05). Preoperative serum creatinine levels were higher in Group 1 in comparison to Group 2 (p<0.001). On postoperative day 1, serum creatinine levels of Group 1 were significantly lower than Group 2 (p<0.001). On postoperative days 3 and 10, no differences were observed regarding serum creatinine levels between groups (p>0.05). Complications were similar between groups (p>0.05). Conclusions. In patients with low ejection fraction undergoing open-heart surgery, the use of levosimendan intraoperatively and 24 hours postoperatively prevents deterioration of renal functions in patients with or without preoperative disturbance in serum creatinine level.

Predictors of atrial fibrillation after off pump coronary artery bypass graft-a prospective observational study

Background: Postoperative atrial fibrillation (AF) is a common and potentially morbid complication following coronary artery bypass graft (CABG) surgery. Many factors have been suggested to increase the incidence of post-operative AF after CABG. Objective was to estimate the proportion of patients developing AF after off pump CABG (OPCABG) and to determine the possible predictors of AF after OPCABG.Methods: This was a prospective observational study done in the department of Cardiovascular and Thoracic Surgery of a tertiary center from December 2019 to December 2020 after obtaining Institutional review board clearance. A sample size of 334 was fixed and patients undergoing OPCABG were consecutively recruited in the study. The association of preoperative and postoperative factors with occurrence of AF were analysed using the univariate analysis with a p value <0.05 using the SPSS 16 software. Multivariate analysis was done to determine the independent predictors after OPCABG.Results: In this prospective study amongst the 334 patients recruited 60 (18%) developed atrial fibrillation and the maximum incidence was seen on the third postoperative day. Patients who developed AF were older with mean age of 61.38±7.63 years, 2.96 (95% CI 0.71-5.21) as compared to those who did not develop AF. Male gender Odds ratio 1.17 (95%CI 1.06-1.31), low ejection fraction 54.95±10.47, -3.25 (95% CI-5.99- -0.52); large atrial size 3.45±0.42, 0.12 (95% CI 0.02-0.06); long intensive care unit (ICU) stay 2.47±0.59, 0.32 (95% CI 0.06-0.21) and long hospital stay 7.62±3.36, 1.48 (95% CI 0.44-0.59) were associated with development of AF after OPCABG. Older age was found to be an independent predictor of development of AF on doing multivariate analysis.Conclusions: In our study advanced age was found to be an independent predictor of atrial fibrillation after OPCABG. Males, low ejection fraction, large atrial size and longer ICU and hospital stays were associated with occurrence of AF after OPCABG.

Use of passive leg rise as an add-on to dobutamine in patients with paradoxical low-flow, low-gradient aortic stenosis

Background Dobutamine has been proposed for the assessment of low-flow, low-gradient aortic stenosis (LFLGAS). However, in 1/3 of patients, no increase in stroke volume index can be achieved by Dobutamine, thus hampering its diagnostic value. This study evaluated the manoeuvre of cardiac preload augmentation by passive leg rise (PLR) alone or on top of Dobutamine to increase stroke volume index (SVI) in patients with LFLGAS, particularly in paradoxical LFLGAS. Methods We examined 50 patients with LFLGAS. Patients were assigned to the paradoxical LFLGAS (Paradox) group if left ventricular ejection fraction (LVEF) was ≥50% (n=29) and to the LFLGAS with low ejection fraction (LEF) group if LVEF was &lt;50% (n=21). A modified Dobutamine stress echocardiography was performed in all patients with the following 4 steps: Rest, PLR alone, maximal Dobutamine infusion rate alone (Dmax) and Dobutamine plus PLR (Dmax + PLR). Three SVI measurement methods were used: first the left ventricular outflow tract velocity time integral (LVOT VTI) method, second the 2D Simpson's method, and third the 3D method. The corresponding aortic valve area (AVA) was obtained by the continuity equation. The increase of those values compared to measurements at rest was calculated and compared between the 3 stress steps. Results In the paradoxical LFLGAS group, delta SVI with Dmax assessed by both Simpson's (depicted in the figures) and 3D method was lowest compared to PLR and Dmax + PLR. PLR alone yielded an equally high delta SVI as Dmax + PLR in Simpson's and 3D, and was at least as high as Dmax across all methods. Dobutamine alone yielded the lowest delta transaortic aortic valve VTI. The highest delta aortic valve area resulted for Dmax + PLR. In the LEF group, the three stress steps yielded an equally high delta SVI with Simpson's method. Dmax never yielded a higher delta SVI than PLR alone. The yielded delta SVI was the highest for Dmax + PLR for both LVOT VTI and 3d method, although the difference was overall not as strong as in the Paradox group. Conclusions In patients with paradoxical LFLGAS, Dobutamine alone is inadequate for testing the potential of aortic valve opening augmentation. Instead, PLR alone or the addition of PLR plus Dobutamine should be used for that purpose. In low LVEF, adding PLR to Dobutamine also seems useful although its diagnostic added value is less evident than in the Paradox group. FUNDunding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Gottfried und Julia Bangerter-Rhyner-Foundation Paradox group Low ejection fraction group

Comparison of Transvalvular Aortic Mean Gradients Obtained by Intraprocedural Echocardiography and Invasive Measurement in Balloon and Self‐Expanding Transcatheter Valves

Background Concerns about discordance between echocardiographic and invasive mean gradients after transcatheter aortic valve replacement (TAVR) with balloon‐expandable valves (BEVs) versus self‐expanding valves (SEVs) exist. Methods and Results In a multicenter study, direct‐invasive and echocardiography‐derived transvalvular mean gradients obtained before and after TAVR were compared as well as post‐TAVR and discharge echocardiographic mean gradients in BEVs versus SEVs in 808 patients. Pre‐TAVR, there was good correlation ( R =0.614; P <0.0001) between direct‐invasive and echocardiography‐derived mean gradients and weak correlation ( R =0.138; P <0.0001) post‐TAVR. Compared with post‐TAVR echocardiographic mean gradients, both valves exhibit lower invasive and higher discharge echocardiographic mean gradients. Despite similar invasive mean gradients, a small BEV exhibits higher post‐TAVR and discharge echocardiographic mean gradients than a large BEV, whereas small and large SEVs exhibit similar post‐TAVR and discharge mean gradients. An ejection fraction <50% ( P =0.028) and higher Society of Thoracic Surgeons predicted risk of mortality score ( P =0.007), but not invasive or echocardiographic mean gradient ≥10 mm Hg ( P =0.378 and P =0.341, respectively), nor discharge echocardiographic mean gradient ≥20 mm Hg ( P =0.393), were associated with increased 2‐year mortality. Conclusions Invasively measured and echocardiography‐derived transvalvular mean gradients correlate well in aortic stenosis but weakly post‐TAVR. Post‐TAVR, echocardiography overestimates transvalvular mean gradients compared with invasive measurements, and poor correlation suggests these modalities cannot be used interchangeably. Moreover, echocardiographic mean gradients are higher on discharge than post‐TAVR in all valves. Despite similar invasive mean gradients, a small BEV exhibits higher post‐TAVR and discharge echocardiographic mean gradients than a large BEV, whereas small and large SEVs exhibit similar post‐TAVR and discharge mean gradients. Immediately post‐TAVR, elevated echocardiographic‐derived mean gradients should be assessed with caution and compared with direct‐invasive mean gradients. A low ejection fraction and higher Society of Thoracic Surgeons score, but not elevated mean gradients, are associated with increased 2‐year mortality.

ICU Stay in Patients with Low Ejection Fraction Undergoing Cardiac Revascularization: Comparison of On-Pump Versus Off-Pump Coronary Artery Bypass Grafting

Background: Coronary artery bypass graft (CABG) surgery can result in serious complications for the patients. It is being currently performed with cardiopulmonary bypass with cardiac arrest in 80% of the cases across the world. There have debate in the past regarding the cardiac revascularization via CABG approaches. Aim: The aim of this study is to study the difference in the patient’s ICU stay who have low ejection fraction and are undergoing cardiac revascularization between off pump and on pump coronary artery bypass grafting. Methodology: A sample size of 60 patients has been taken in the study with 30 patients' in the on-pump surgery group and 30 patients' in the off-pump surgery group. The data has been collected from department of Cardiac Srugery AFIC/NIHD, Rawalpindi. Results and Conclusion: The study concludes that the on-pump CABG patients tend to have shorter ICU stay than the off-pump CABG patients who have low ejection fraction and are undergoing cardiac revascularization. Therefore, on-pump treatment is recommended in the study. Keywords: Off pump, on pump, coronary artery bypass grafting, ICU stay, low ejection fraction, cardiac revascularization