Myocardial protection by isoflurane vs. sevoflurane in ultra-fast-track anaesthesia for off-pump aortocoronary bypass grafting

Pre- and Post-Conditioning of the Heart: An Overview of Cardioprotective Signaling Pathways

Since the discovery of ischemic pre- and post-conditioning, more than 30 years ago, the knowledge about the mechanisms and signaling pathways involved in these processes has significantly increased. In clinical practice, on the other hand, such advancement has yet to be seen. This article provides an overview of ischemic pre-, post-, remote, and pharmacological conditioning related to the heart. In addition, we reviewed the cardioprotective signaling pathways and therapeutic agents involved in the above-mentioned processes, aiming to provide a comprehensive evaluation of the advancements in the field. The advancements made over the last decades cannot be ignored and with the exponential growth in techniques and applications. The future of pre- and post-conditioning is promising.

Total Intravenous Anesthesia Maintained the Degree of Pre-Existing Mitral Regurgitation Better than Isoflurane Anesthesia in Cardiac Surgery: A Randomized Controlled Trial

Accurate assessment of mitral regurgitation (MR) is critical during mitral valve repair surgery. However, anesthesia may influence the degree of mitral regurgitation by changing pre- and after-load or cardiac contractility. Therefore, we compared changes in mitral regurgitation by total intravenous anesthesia (TIVA) and inhalation anesthesia in patients with pre-existing mitral regurgitation. This was a double-blind randomized controlled study conducted at a tertiary care center in 2018. Fifty-four mitral regurgitation patents undergoing elective cardiac surgery were randomly assigned to receive TIVA or isoflurane. Primary endpoint was change of regurgitation volume by anesthesia. The reduction of regurgitation volume by anesthesia was greater in the isoflurane group than in the TIVA group (mean (95% confidence interval CI): -0.20 (-6.15, 5.75) vs. -9.66 (-15.77, -3.56), mL·beat^-1, p = 0.0266) and this phenomenon was more prominent with severe mitral regurgitation (grade 3 or 4) (mean (95% CI): -0.33 (-9.10, 8.44) vs. -16.20 (-24.22, -8.18), mL·beat^-1, p = 0.0079). Among patients with MR grade 3 or 4, 94% remained the same with TIVA during anesthesia compared to 56% with isoflurane. In conclusion, TIVA maintained the pre-anesthetic state of mitral regurgitation relatively well, while the severity of mitral regurgitation tended to decrease with isoflurane anesthesia.

The Impact of Volatile Anesthetic Choice on Postoperative Outcomes of Cardiac Surgery: A Meta-Analysis

OBJECTIVES

To evaluate the impact of volatile anesthetic choice on clinically relevant outcomes of patients undergoing cardiac surgery.

METHODS

Major databases were systematically searched for randomized controlled trials (RCTs) comparing volatile anesthetics (isoflurane versus sevoflurane) in cardiac surgery. Study-level characteristics, intraoperative events, and postoperative outcomes were extracted from the articles.

RESULTS

Sixteen RCTs involving 961 patients were included in this meta-analysis. There were no significant differences between both anesthetics in terms of intensive care unit length of stay (SMD -0.07, 95% CI -0.38 to 0.24, P = 0.66), hospital length of stay (SMD 0.06, 95% CI -0.33 to 0.45, P = 0.76), time to extubation (SMD 0.29, 95% CI -0.08 to 0.65, P = 0.12), S100β (at the end of surgery: SMD 0.08, 95% CI -0.33 to 0.49, P = 0.71; 24 hours after surgery: SMD 0.21, 95% CI -0.23 to 0.65, P = 0.34), or troponin (at the end of surgery: SMD -1.13, 95% CI -2.39 to 0.13, P = 0.08; 24 hours after surgery: SMD 0.74, 95% CI -0.15 to 1.62, P = 0.10). CK-MB was shown to be significantly increased when using isoflurane instead of sevoflurane (SMD 2.16, 95% CI 0.57 to 3.74, P = 0.008).

CONCLUSIONS

The volatile anesthetic choice has no significant impact on postoperative outcomes of patients undergoing cardiac surgery.

Comparison of isoflurane and sevoflurane in cardiac surgery: a randomized non-inferiority comparative effectiveness trial

Purpose

Volatile anesthetics possess cardioprotective properties, but it is unknown if the cardioprotective effects extend equally to all members of the class. Although sevoflurane is a relatively newer anesthetic than isoflurane, its introduction into practice was not preceded by a head-to-head comparison with isoflurane in a trial focusing on clinically important outcomes. Our objective was to determine whether sevoflurane was non-inferior to isoflurane on a clinically important primary outcome in a heterogeneous group of adults undergoing cardiac surgery.

Methods

This was a pragmatic randomized non-inferiority comparative effectiveness clinical trial in 464 adults having coronary artery bypass graft and/or single valve surgery during November 2011 to March 2014. The intervention was maintenance of anesthesia with sevoflurane (n = 231) or isoflurane (n = 233) administered at a dose of 0.5-2.0 MAC throughout the entire operation. All caregivers were blinded except for the anesthesiologist and perfusionist. The primary outcome was a composite of intensive care unit (ICU) length of stay ≥ 48 hr and all-cause 30-day mortality. We hypothesized that sevoflurane would be non-inferior to isoflurane (non-inferiority margin < 10% based on an expected event rate of 25%). Secondary outcomes included prolonged ICU stay, 30- and 365-day all-cause mortality, inotrope or vasopressor usage, new-onset hemodialysis or atrial fibrillation, stroke, and readmission to the ICU.

Results

No losses to follow-up occurred. The primary outcome occurred in 25% of sevoflurane patients and 30% of isoflurane patients (absolute difference, −5.4%; one-sided 95% confidence interval, 1.4), thus non-inferiority was declared. Sevoflurane was not superior to isoflurane for the primary outcome (P = 0.21) or for any secondary outcomes.

Conclusion

Sevoflurane is non-inferior to isoflurane on a composite outcome of prolonged ICU stay and all-cause 30-day mortality. Sevoflurane is not superior to isoflurane on any other of the clinically important outcomes. This trial was registered at clinicaltrials.gov; NCT01477151.

Evaluation of the influence of pulmonary hypertension in ultra-fast-track anesthesia technique in adult patients undergoing cardiac surgery

Objective

To evaluate the influence of pulmonary hypertension in the ultra-fast-track anesthesia technique in adult cardiac surgery.

Methods

A retrospective study. They were included 40 patients divided into two groups: GI (without pulmonary hypertension) and GII (with pulmonary hypertension). Based on data obtained by transthoracic echocardiography. We considered as the absence of pulmonary hypertension: a pulmonary artery systolic pressure (sPAP) <36 mmHg, with tricuspid regurgitation velocity <2.8 m/s and no additional echocardiographic signs of PH, and PH as presence: a sPAP >40 mmHg associated with additional echocardiographic signs of PH. It was established as influence of pulmonary hypertension: the impossibility of extubation in the operating room, the increase in the time interval for extubation and reintubation the first 24 hours postoperatively. Univariate and multivariate analyzes were performed when necessary. Considered significant a P value <0.05.

Results

The GI was composed of 21 patients and GII for 19. All patients (100%) were extubated in the operating room in a medium time interval of 17.58±8.06 min with a median of 18 min in GII and 17 min in GI. PH did not increase the time interval for extubation (P=0.397). It required reintubation of 2 patients in GII (5% of the total), without statistically significant as compared to GI (P=0.488).

Conclusion

In this study, pulmonary hypertension did not influence on ultra-fast-track anesthesia in adult cardiac surgery.

Circulating microRNAs indicate cardioprotection by sevoflurane inhalation in patients undergoing off-pump coronary artery bypass surgery

In patients undergoing off-pump coronary artery bypass surgery (OPCAB), it is important to attenuate myocardium injury during the surgery. The present study aimed to observe the cardioprotection induced by sevoflurane induction and maintenance compared with propofol intravenous anesthesia, and to detect its potential protection against acute myocardial injury with sensitive biomarkers. In total, 36 patients undergoing OPCAB were randomly assigned into two groups, receiving sevoflurane (n=18) or propofol (n=18) as the induction and maintenance anesthetic agent. The depth of anesthesia in the two groups was kept at a bispectral index value of 40-50. Physiological and hemodynamic parameters were recorded during the surgery. Cardiac troponin-I (cTnI), creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH) and two microRNAs (miR-499 and miR-208b) were also measured during and subsequent to surgery. Nno statistically significant differences were observed in the physiological and hemodynamic parameters between the two groups prior to surgery. Following surgery, the cardiac output and stroke volume improved significantly in the sevoflurane group (P<0.05). In addition, patients in the sevoflurane group had lower miR-499 (P<0.05) and miR-208b (P<0.01) levels at 12 h after surgery when compared with the propofol group. However, no significant differences in cTnI, CK-MB and LDH levels were observed following surgery between the two groups. In conclusion, volatile induction and maintenance with sevoflurane resulted in some extent of cardiac function improvement in patients undergoing OPCAB. Cardioprotection by sevoflurane is suggested by reduced cardiac injury compared with propofol, and indicated by the sensitive biomarkers, circulating miR-499 and miR-208b.

Anaesthetic management for balloon dilation of cor triatriatum dexter in a dog

A three-month-old female Rottweiler puppy was referred for intravascular correction of a previously identified cor triatriatum dexter. Echocardiography confirmed the presence of a hyperechoic membrane that divided the right atrium into a cranial and caudal chamber. A foramen in this membrane allowed the blood to flow from the caudal to the cranial chamber. Balloon dilation of the defect under transthoracic echocardiographic guidance was scheduled for the following day. The dog was premedicated with 0.5 μg/kg sufentanil and 0.2 mg/kg midazolam administered intravenously. General anaesthesia was induced with 2 mg/kg propofol and maintained with inhaled isoflurane in oxygen; at the same time, a constant rate infusion of 0.5 μg/kg/h sufentanil was administered by means of an infusion pump. Uneventful ventricular and supraventricular tachyarrhythmias developed during the placement of catheters and balloon dilation. At the end of procedure, when the guide wire and balloon catheter were removed, normal sinus rhythm was observed. To the authors’ knowledge, no previous reports have described the anaesthetic management of a balloon dilation procedure for cor triatriatum dexter in dogs.

The effect of sevoflurane versus propofol anesthesia on troponin I after congenital heart surgery, a randomized clinical trial

Background:

The ischemic preconditioning phenomenon can save myocardium against move severe ischemic damages and reduce infarction size and furthermore a heart rhythm disturbance. In this study we examine relationship between troponin I (as a structural myocardial protein) level and anesthetic agents in the children.

Materials and Methods:

In this study 84 children under 12 years age before cardiac surgery were divided randomly into two groups of 42 each. For anesthetic maintenance sevoflurane with dose of 0.5-1 MAC was used in Group 1 and 100-150 mg/kg/min of intravenous propofol in Group 2 for maintenance of anesthesia. Troponin I level was assessed 2 before and 1 hour after anesthetic induction. Outcome measures included the serum cardiac troponin I level in children before and after surgery in two study groups.

Results:

There was no significant difference between two groups in indices and both groups were homogenous in this point of view. The troponin I level after surgery was significantly increased in two groups. In the sevoflurane group it was 0.04 ± 0.12 to 0.05 ± 0.09 ng/ml (P value = 0.003) and the propofol group was 0.12 ± 0.26 to 0.19 ± 0.38 ng/ml (P value = 0.001).

Conclusions:

In this study two Anesthetic regimens were compared to assess the mean troponin I level before and after pediatric closed heart surgery, and it was shown that mean troponin level before and after surgery in the sevoflurane group was less than the propofol group. But this result was not statistically significant. These results indicate that although more protective effects of sevoflurane on myocardial injuries during pediatric cardiac surgery is predominant but this effect has no significant difference in the propofol group.

Association of Robotic Totally Endoscopic Coronary Artery Bypass Graft Surgery Associated With a Preliminary Cardiac Enhanced Recovery After Surgery Program: A Retrospective Analysis

OBJECTIVES

The robotic totally endoscopic coronary artery bypass graft (TECAB) surgery reduces patients' recovery time. The present trial investigated the feasibility and safety of an initial enhanced recovery after surgery (ERAS) path for patients undergoing robotic beating-heart TECAB and compared it with both conventional surgery and traditional perioperative care. It was hypothesized that the preliminary ERAS pathway associated with a beating-heart TECAB procedure could have a synergistic effect on postoperative patient care.

DESIGN

Observational retrospective study.

SETTING

University hospital.

PARTICIPANTS

Patients scheduled for coronary artery bypass graft and undergoing robotic beating-heart TECAB (n = 38) were compared with those undergoing standard surgery and perioperative care (n = 33). The outcomes were the possibility of tracheal extubation at the end of the surgery and the incidence of postoperative complications.

MEASUREMENTS AND MAIN RESULTS

The main comorbidities were similar between the 2 groups. Extubation on the operating table in the TECAB group was possible in all cases without requiring prompt endotracheal tube reinsertion. The proportion of patients transfused was significantly lower in the TECAB group (p = 0.009). In addition, the duration of intensive care unit and hospital stay were reduced significantly by 24 hours and by 4 days, respectively, in the TECAB group compared with the standard group (p< 0.05).

CONCLUSIONS

The present results suggested that a program coupling a beating-heart TECAB with a preliminary ERAS path for patients requiring a single coronary revascularization is feasible and safe. This approach could reduce postoperative mechanical ventilation time, transfusion rate, and both intensive care unit and hospital stay.

Myocardial conditioning techniques in off-pump coronary artery bypass grafting

Off-pump coronary artery bypass surgery by avoiding cardioplegic arrest seems to reduce the risk of ischemic myocardial injury. However, even short-term regional ischemic periods, hemodynamic instability and arrhythmias associated with the procedure can be responsible for myocardial damage. Conditioning, a potential cardio-protective tool during on-pump cardiac surgery, has hardly been investigated in the context of off-pump surgery. There are virtually no large trials on remote ischemic preconditioning and the majority of reports have focused on central ischemic conditioning. Similarly, volatile anesthetic agents with conditioning effect like ischemic preconditioning have been shown to reduce cardiac injury during on-pump procedures but have not been validated in the off-pump scenario. Here, we review the available evidence on myocardial conditioning, either with ischemia/reperfusion or volatile anesthetic agents in patients undergoing off-pump coronary artery surgery.

Sevoflurane in acute myocardial infarction: a pilot randomized study

BACKGROUND

Experimental evidence suggests that the inhalational anesthetic sevoflurane has a cardioprotective effect. Our objective was to determine if sedation with sevoflurane will reduce infarct size in patients with acute myocardial infarction (MI) who are treated with primary percutaneous coronary intervention (PCI).

METHODS

We randomized 50 patients presenting with a first acute ST-elevation MI treated by primary PCI within 6 hours from symptom onset to sedation with sevoflurane inhalation or standard sedation (control). Coronary flow at the end of PCI was assessed by corrected Thrombolysis In Myocardial Infarction frame count. Myocardial reperfusion was assessed by ST-segment resolution 60 minutes post-PCI. Infarct size was assessed by release of creatinine kinase (CK) and troponin T.

RESULTS

There was no difference in the primary end point: troponin T or CK release adjusted to the area at risk, between groups. However, among patients with anterior MI, there was a trend toward lower CK (P = .05) and nonsignificant decrease in troponin (P = .11) levels in the sevoflurane group. Corrected Thrombolysis In Myocardial Infarction frame count was 12.3 ± 1.5 in the sevoflurane group and 15.6 ± 9.1 in the control group (P = .16). There was more ST resolution in patients treated by sevoflurane 80.7% ± 25.8% versus 56.6% ± 35.7% (P = .01). Sevoflurane had no significant adverse effect during administration.

CONCLUSIONS

Sevoflurane administration during primary PCI did not reduce infarct size. There was a trend toward a reduction in infarct size among patients with anterior MI. Sevoflurane administration was associated with improvement in ST-segment resolution.

Sevoflurane preconditioning attenuates myocardial ischemia/reperfusion injury via caveolin-3-dependent cyclooxygenase-2 inhibition

BACKGROUND

The inhaled anesthetic sevoflurane has been demonstrated to protect against myocardial ischemia/reperfusion (MI/R) injury via mechanisms involving AMP-activated protein kinase (AMPK) and caveolin-3 (Cav-3). However, the relative contributions of AMPK and Cav-3 to sevoflurane preconditioning (SF-PreCon)-mediated cardioprotection and their precise underlying mechanisms of action remain incompletely understood.

METHODS AND RESULTS

SF-PreCon (consisting of 3 cycles of 15-minute exposure to 2% sevoflurane before 30 minutes of MI) decreased MI/R injury in wild-type mice (caspase-3 activity, -29.1%; infarct size, -20.2%; and left ventricular end diastolic pressure, -33.8%). In cardiac-specific AMPKα2 dominant-negative overexpressing mice, the cardioprotective effect of SF-PreCon was largely retained (caspase-3 activity, -26.7%; infarct size, -16.7%; and left ventricular end-diastolic pressure, -25.9%; P<0.01). In contrast, SF-PreCon failed to significantly protect Cav-3 knockout mice against MI/R injury (P>0.05). SF-PreCon significantly decreased MI/R-induced superoxide generation in wild-type (-43.6%) and AMPK dominant-negative overexpressing mice (-35.5%; P<0.01) but not in Cav-3 knockout mice. SF-PreCon did not affect nicotinamide adenine dinucleotide phosphate oxidase expression but significantly inhibited cyclooxygenase-2 expression in wild-type (-38.7%) and AMPK dominant-negative overexpressing mice (-35.8%) but not in Cav-3 knockout mice.

CONCLUSIONS

We demonstrate for the first time SF-PreCon mediates cardioprotection against MI/R injury via caveolin-3-dependent cyclooxygenase-2 inhibition and antioxidative effects.

The effect of isoflurane on survival and myocardial infarction: a meta-analysis of randomized controlled studies

OBJECTIVE

The aim of this meta-analysis was to investigate the cardioprotective properties of isoflurane versus any comparator in terms of the rate of myocardial infarction and all-cause mortality.

DESIGN

Pertinent studies were searched independently in Biomed, Central, PubMed, Embase, and the Cochrane Central Register of clinical trials. The primary endpoint was mortality at the longest follow-up available.

SETTING

A hospital.

PARTICIPANTS

Randomized controlled trials.

INTERVENTION

A meta-analysis of 37 trials.

MEASUREMENTS AND MAIN RESULTS

The 37 included trials randomized 3,539 patients in cardiac (16 studies) and in noncardiac surgery (21 studies) with noninhalation comparators in 55% of trials. The overall analysis showed no difference in mortality between the isoflurane and control groups (16/1,602 [1.0%] v 23/1,937 [1.2%], odds ratios (OR) = 0.76 [0.39-1.47], p = 0.4 with 37 studies included) and no difference in the rate of myocardial infarction (3/1,312 [0.2%] v 1/1,532 [0.07%], OR = 2.03 [0.27-15.49], p = 0.5 with 30 studies included). Mortality was reduced in the isoflurane group when only studies with a low risk of bias were included in the analyses (0/540 [0%] v 5/703 [0.7%] in the control arm, OR = 0.13 [0.02-0.76], p = 0.02) with 4 cardiac and 6 noncardiac trials included and 5 noninhalation and 5 inhalation agents as the comparator. A trend was noted when a subanalysis was performed with propofol as a comparator (1/544 [0.2%] v 6/546 [1.1%], p = 0.05, with 16 studies included).

CONCLUSIONS

Isoflurane reduced mortality in high-quality studies and showed a trend toward a reduction in mortality when it was compared with propofol. No differences in the rates of overall mortality and myocardial infarction were noted.

Anesthetic management for cesarean delivery in a patient with severe aortic stenosis and severe obesity

Valvular heart disease has significant effect on the maternal and fetal outcome of pregnancy. The severity and extent of aortic stenosis is of great value for risk assessment and for the design of a therapeutic plan. The therapeutic plan for such patients is further complicated by severe obesity. We report a case describing the anesthetic management of an extremely obese patient for cesarean delivery with severe aortic valve stenosis and regurgitation. The case was made complex due to the patient's deteriorating condition and not offering consent to emergency surgical procedures. The 34-year-old parturient underwent cesarean delivery at 32 weeks gestation under general anesthesia in the presence of a cardiothoracic surgical team. This case report demonstrates the importance of multidisciplinary preoperative assessment in such patients and careful anesthetic planning to avoid the deterioration of perioperative cardiac performance in parturients with complex valvular disease.