Association of perioperative myocardial ischemia with cardiac morbidity and mortality in men undergoing noncardiac surgery. The Study of Perioperative Ischemia Research Group

The Significance of Equipment Availability and Anesthesia Educational Conferences to Decision-Making for EKG Lead V5 Abnormalities

Introduction To predict postoperative myocardial infarction rates in patients who undergo noncardiac surgery, the Canadian Cardiovascular Society Guidelines on Perioperative Cardiac Risk Assessment and Management recommends assessment of brain natriuretic peptide (BNP) in certain patients. Serial troponins are measured if the BNP level is elevated. In certain cases, Revised Cardiac Risk Index (RCRI) alone does not perform well, for example, during vascular surgery. Cardiac events occur in 20% of all vascular surgery patients. The odds ratio for such events is 9.2 if ST segments were depressed by 1 mm intraoperatively (relative to the PR interval) within the first 48 hours postoperatively. Increasing the number of cables and pads from three to five for electrocardiogram (EKG) increases the sensitivity from around 30% to over 80% for ischemic events relative to a formal EKG stress test, and then the monitor continuously displays not only lead II but also lead V5. Methods Our hypothesis was that raising awareness about diagnostic and therapeutic options to reduce the risk of postoperative myocardial infarction would increase the use of five pads. We conducted open-ended surveys at six hospitals to assess the reasons for choosing three pads. In our university hospital practice, we measured a cross-sectional incidence of using three pads before and, once again, a month after an intervention during a single morning. Several resident conferences encouraged the use of five pads. Education included weekly lectures and informal discussions with other staff during surgery, demonstrating that using five pads allows interrogation of an entire 12-lead EKG. In comparison, three pads only allow viewing three leads. Results At baseline, only three pads were available in 96% of our 23 operating rooms. Five cables were available in eight of those surgeries, but two were taped off to the side. Surveys unveiled scarcity of equipment and, more importantly, disempowerment (i.e., knowing how to diagnose or when to treat ischemia). After several conferences, the prevalence of equipment availability of only three pads fell to 47%. Conclusions Education enumerated details of recognizing ischemic configurations of ST depression. Next, education revealed methods to interrupt the progression of ischemia to infarction such as elevated blood pressure and hematocrit, reducing heart rate, and calling a cardiology consultant if the anesthesiologist wishes to draw serial troponins. Barriers to implementing an enhanced recovery after surgery (ERAS) pathway began with a need for more access to manage stress tests or optimize blood pressure medications after a preoperative anesthesia evaluation. The intraoperative barrier was knowing what to do if ST depression occurs. Therefore, we began raising awareness by encouraging the addition of an element of a future ERAS pathway, adding a cost of only $1 to monitor lead V5. Future ERAS pathways can include preoperative stress tests and consults, as found in published guidelines.

Prediction of Complications and Prognostication in Perioperative Medicine: A Systematic Review and PROBAST Assessment of Machine Learning Tools

BACKGROUND

The utilization of artificial intelligence and machine learning as diagnostic and predictive tools in perioperative medicine holds great promise. Indeed, many studies have been performed in recent years to explore the potential. The purpose of this systematic review is to assess the current state of machine learning in perioperative medicine, its utility in prediction of complications and prognostication, and limitations related to bias and validation.

METHODS

A multidisciplinary team of clinicians and engineers conducted a systematic review using the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) protocol. Multiple databases were searched, including Scopus, Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Cochrane Library, PubMed, Medline, Embase, and Web of Science. The systematic review focused on study design, type of machine learning model used, validation techniques applied, and reported model performance on prediction of complications and prognostication. This review further classified outcomes and machine learning applications using an ad hoc classification system. The Prediction model Risk Of Bias Assessment Tool (PROBAST) was used to assess risk of bias and applicability of the studies.

RESULTS

A total of 103 studies were identified. The models reported in the literature were primarily based on single-center validations (75%), with only 13% being externally validated across multiple centers. Most of the mortality models demonstrated a limited ability to discriminate and classify effectively. The PROBAST assessment indicated a high risk of systematic errors in predicted outcomes and artificial intelligence or machine learning applications.

CONCLUSIONS

The findings indicate that the development of this field is still in its early stages. This systematic review indicates that application of machine learning in perioperative medicine is still at an early stage. While many studies suggest potential utility, several key challenges must be first overcome before their introduction into clinical practice.

EDITOR’S PERSPECTIVE

An increase in tumor size increases the risk of the development of postoperative cardiopulmonary events in patients undergoing partial nephrectomy

PURPOSE

The aim of this study was to examine the effect of kidney tumor size on the risk of CPE developing in the first postoperative month.

MATERIAL AND METHODS

Evaluation was made of 127 patients who underwent PN between January 2010 and November 2022. The patients were separated into two groups as Group 1 (n: 13) including patients who developed CPE within the first postoperative month and Group 2 (n: 114) of patients who did not develop CPE. The factors that could affect CPE and overall survival were analyzed with multivariate logistic and Cox regression analysis, respectively.

RESULTS

The groups were determined to be similar in respect of age, gender and Charlson Comorbidity Index (p = 0.35, p = 0.68, p = 0.42, respectively). The values of mean tumor size (48.6 ± 12.9 vs. 29.2 ± 8.7 mm, p < 0.001), clinical T1b stage (61.5% vs. 9.6%, p < 0.001), median R.E.N.A.L. Nephrometry Score (9[3] vs.6 [1], p = 0.001) and mean warm ischaemia time (21.2 ± 3.5 vs. 15.9 ± 2.63 min, p < 0.001) were determined to be statistically significantly higher in Group 1 than in Group 2. In the ROC curve analysis performed to predict the development of CPE within the first postoperative month, 35.5 mm was determined to be the best cut-off point for tumor diameter (AUC = 0.88, p < 0.001). In the multivariate analysis, the presence of CPE for overall survival, and increased tumor size for the development of CPE were each determined to be independent risk factors (OR: 3.25, p = 0.03; OR: 1.4, p = 0.001, respectively).

CONCLUSION

Tumor size serves as a significant marker for the development of CPE within the initial month following PN.

ASA Physical Status Determination by General Internists and Impact on Cardiac Risk Assessment

OBJECTIVES

Estimating cardiac risk is important for preoperative evaluation, and several risk calculators incorporate the American Society of Anesthesiologists (ASA) physical status score. The purpose of this study was to determine the concordance of ASA scores assigned by general internists and anesthesiologists and assess whether discrepancies affected cardiac risk estimation.

METHODS

This observational study included military veterans evaluated in a preoperative evaluation clinic at a single center during a 12-month period. ASA scores were recorded by General Internal Medicine residents under the supervision of a General Internal Medicine attending, performing a preoperative medical consultation, and were compared with ASA scores assigned by an anesthesiologist on the day of surgery. ASA scores and Gupta Cardiac Risk Scores incorporating each ASA score were compared.

RESULTS

Data were collected on 206 patients, 163 of whom had surgery within 90 days and were included. ASA scores were concordant in 60 patients (37.3%), whereas the ASA scores were rated lower by the general internist in 101 (62.0%) and higher in 2 (1.2%). Interrater reliability was low (κ = 0.08), and general internist scores were significantly lower than anesthesiologist scores (P < 0.01). Gupta Cardiac Risk Scores were calculated for 160 patients, and they exceeded 1% in 14 patients using the anesthesiologist ASA score, compared with 5 patients using the general internist score.

CONCLUSIONS

ASA scores assigned by general internists in this study were significantly lower than those assigned by anesthesiologists, and these discrepancies in the ASA score can lead to substantially different conclusions about cardiac risk.

Limitations to Health Care Quality Measurement: Assessing Hospital Variation in Risk of Cardiac Events After Noncardiac Surgery

Limited sample size, incomplete measures, and inadequate risk adjustment adversely influence accurate health care quality measurements, surgical quality measurements, and accurate comparisons among hospitals. Since these measures are linked to resources for quality improvement and reimbursement, improving the accuracy of measurement has substantial implications for patients, clinicians, hospital administrators, insurers, and purchasers. The team examined risk-adjusted differences of postoperative cardiac events among 20 geographically dispersed, community-based medical centers within an integrated health care system and compared it with the National Surgical Quality Improvement Program (NSQIP) hospital-specific differences. The exposure included the hospital at which patients received noncardiac surgical care, with stratification of patients by the acuity of surgery (elective vs. urgent/emergent). Among 157,075 surgery patients, the unadjusted risk of cardiac event per 1000 ranged among hospitals from 2.1 to 6.9 for elective surgery and from 10.3 to 44.5 for urgent/emergent surgery. Across the 20 hospitals, hospital rankings estimated in the present analysis differed significantly from ranking reported by NSQIP (P for difference: elective, P = 0.0001; urgent/emergent, P < 0.0001) with significantly and substantially lower variation after risk adjustment. Current surgical quality measures may not adequately account for limitations of sample size, data capture, adequate risk adjustment, and surgical acuity in a given hospital, particularly for rare outcomes. These differences have implications for quality reporting and may introduce bias into hospital comparisons, particularly for hospitals with incomplete capture of their patients' baseline risk and acuity.

Dexmedetomidine reduces myocardial ischemia-reperfusion injury in young mice through MIF/AMPK/GLUT4 axis

BACKGROUND

Reperfusion of ischemic tissue has adverse impact on the myocardium. Dexmedetomidine (Dex) is a α2-adrenergic receptor (α2-AR) agonist with sedative and analgesic effects. Macrophage migration inhibition factor (MIF) is a pressure-regulating cytokine and is responsible for inflammatory and immune diseases. This study aims to reveal the consequences of Dex on myocardial ischemia-reperfusion injury (IRI) in young mice.

METHODS

Fifty mice were raised and examined. At the end of the experiment, all mice were euthanized. The anterior descending department of the left coronary artery in mice was under ischemia for 60 min, then the ligation line was released and reperfused for 120 min to establish the IRI model. Mice were randomly divided into Sham, control, treatment using 4,5-dihydro-3-(4-hydroxyphenyl)-5-isoxazoleacetic acid (ISO-1), Dex treatment, and Dex combined ISO-1 treatment groups. Interleukin (IL)-6, IL-10 and tumor necrosis factor (TNF-α) were determined by enzyme-linked immunosorbent assay (ELISA). Reactive oxygen species (ROS) and ATP levels were recorded. The expressions of MIF, P-adenosine monophosphate-activated kinase α (AMPKα), glucose transporter (GLUT)4, Bax and Bcl-2 were detected by Western Blot (WB). Hematoxylin and Eosin (H&E) staining was used to study cell morphology. Apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay. Echocardiography was carried out at the end of reperfusion, and the infarct size was calculated by Electron microscopy.

RESULTS

I/R + Dex group showed significantly increased IL-6 and TNF-α levels and reduced myocardial cell necrosis and apoptosis. H&E staining showed alleviated myocardial disorder, myocardial cell swelling, myocardial fiber fracture, and inflammatory cell infiltration in I/R + Dex group. Myocardial cell necrosis and apoptosis were significantly reduced in I/R + Dex group. ATP level in myocardial tissue of mice in I/R group was substantially decreased, while that in Dex group was increased. WB results showed that MIF, P-AMPK α, GLUT4 and Bcl-2 levels were increased and Bax levels were decreased in I/R + Dex group.

CONCLUSION

Dex may exert myocardial protection in young mice through MIF/AMPK/GLUT4 axis.

Estimation of the Risk of Postoperative Hypertension Following Minor to Moderate Surgery Using an Echocardiogram and Biomarkers

This study aimed to determine independent factors for developing postoperative hypertension using 4 biomarkers in patients receiving oral and maxillofacial surgery under general anesthesia. Brain natriuretic peptide (BNP), N-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity myocardial troponin T (hs-TnT), and high-sensitivity myocardial troponin I (hs-TnI) were measured and preoperative echocardiograms were examined. Episodes of systolic blood pressure (SBP) ≥ 170 mmHg or diastolic blood pressure ≥ 100 mmHg within 1 week after surgery were considered postoperative hypertension. We analyzed 213 (130 men; 83 women) patients, who were divided into a postoperative hypertension group (HT group, n = 32) and a normal group (N group, n = 181). The HT group showed a higher LVMI (113.5 versus 100.1), higher E/e' of the lateral wall (9.1 versus 7.7), and higher BNP (39.2 versus 22.9 pg/mL), NT-proBNP (400.1 versus 143.9 pg/mL), and hs-TnT (15.6 versus 10.3 ng/L) concentrations compared to the N group. NT-proBNP and hs-TnT concentrations positively associated with E/e', but BNP and hs-TnI did not. NT-proBNP (AUC = 0.64, cutoff value: 117.0 pg/mL) and hs-TnT (AUC = 0.61, cutoff value: 11.0 ng/L) concentrations were effective for discriminating E/e' ≥ 12. Multivariate logistic regression analyses showed that risk factors responsible for developing postoperative hypertension were NT-proBNP and hs-TnT using biomarkers and E/e' as independent variables, and NT-proBNP and SBP at admission using biomarkers and SBP at admission as independent variables. These findings suggest that NT-proBNP and hs-TnT concentrations, and SBP at admission, are useful to predict postoperative hypertension after minor to moderate surgery, and that left ventricular filling pressure is a primary factor associated with postoperative hypertension.

The Predictive Role of Cardiac Troponin in Non-cardiac Surgery: A Study in the Greek Population

Introduction

The incidence of postoperative myocardial ischemia (POMI) remains uncertain and underdiagnosed despite significant morbidity and mortality rates.

Methods

This study included patients who underwent non-cardiac surgery. Troponin T (TnT) was measured on the first three postoperative days. The revised cardiac risk index, HAS-BLED (hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio (INR), elderly, drugs/alcohol concomitantly) bleeding score, and CHA2DS2-VASc (congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, stroke or transient ischemic attack (TIA), vascular disease, age 65 to 74 years, sex category) score were combined. The receiver operating characteristic (ROC) curve was used to estimate the discriminative ability of preoperative troponin for myocardial ischemia (MI).

Results

Of 105 patients with a mean age of 69.1 years, 32.4% had MI. Hypertension, diabetes mellitus, and dyslipidemia were the main risk factors. A ROC analysis indicated that a preoperative value of 17.2 pg/ml or higher of troponin was significantly associated with MI. Moreover, a higher CHA2DS2-VASc score was associated with POMI.

Conclusions

POMI is associated with high mortality and a long stay in the intensive care unit. Routine use of different scores before surgery can be very useful.

Management of Postoperative Myocardial Injury After Non-cardiac Surgery in Patients Aged ≥ 80 Years: Our 10 Years' Experience

Background

Postoperative myocardial injury (PMI) is associated with short- and long-term mortality. The incidence of PMI in very old patients is currently unknown. There is currently neither known effective prophylaxis nor a uniform strategy for the elderly with PMI.

Objective

To share our 10 years of experience in the comprehensive management of PMI after non-cardiac surgery in patients aged ≥ 80 years.

Methods

In this case series, we retrospectively collected and assessed the 2,984 cases aged ≥ 80 years who accepted non-cardiac surgery from 2011 to 2021 at the second Medical Center, Chinese PLA General Hospital. The incidence, risk factors, management strategy, and prognosis of surgical patients with PMI were analyzed.

Results

A total of 2,984 patients met our inclusion criteria. The overall incidence of PMI was 14%. In multivariable analysis, coronary artery disease, chronic heart failure, and hypotension were independently associated with the development of PMI. The patients with PMI were at a higher risk of death (OR, 2.69; 95% CI, 1.78–3.65). They were more likely to have received low molecular heparin, anti-plantlet therapy, beta-blocker, early coronary angiography, and statin than patients without PMI. The 30-day (0.96% vs. 0.35%; OR 3.46; 95% CI, 1.49–7.98; P &lt; 0.001) and 1-year mortality (5.37% vs. 2.60%; OR 2.35; 95% CI, 1.12–6.53; P &lt; 0.001) was significantly higher in patients with PMI compared with those without PMI.

Conclusions

The incidence of PMI in very old patients was high. The PMI is associated with an increased risk of 30 days and 1-year mortality. These patients can benefit from intensification of assessment and individualized care of multi-morbidities during the perioperative period. Especially cardiovascular medical treatments, such as antiplatelet, anticoagulation, β-blockers, and statins are very important for patients with PMI.

Major adverse cardiovascular events following partial nephrectomy: a procedure-specific risk index

Introduction:

Partial nephrectomy (PN) is associated with a non-negligible risk of postoperative cardiovascular morbidity and mortality. Identification of high-risk patients may enable optimization of perioperative management and consideration of alternative approaches. The authors aim to develop a procedure-specific cardiovascular risk index for PN patients and compare its performance to the widely used revised cardiac risk index (RCRI) and AUB-HAS2 cardiovascular risk index.

Methods:

The cohort was derived from the American College of Surgeons – National Surgical Quality Improvement Program (ACS-NSQIP) database. The primary outcome was the incidence of major adverse cardiovascular events (MACE), defined as 30-day postoperative incidence of myocardial infarction, stroke, or mortality. A multivariate logistic regression model was constructed; performance and calibration were evaluated using an ROC analysis and the Hosmer–Lemeshow test and compared to the RCRI and the AUB-HAS2 index.

Results:

In a cohort of 4795 patients, MACE occurred in 52 (1.1%) patients. A univariate analysis yielded 13 eligible variables for entry into the multivariate model. The final PN-A₄CH model utilized six variables: Age ⩾75 years, ASA class >2, Anemia, surgical Approach, Creatinine >1.5, and history of Heart disease. Index ROC analysis provided a C-statistic of 0.81, calibration R² was 0.99, and sensitivity was 85%. In comparison, the RCRI and AUB-HAS2 C-statistics were 0.59 and 0.68, respectively.

Conclusion:

This study proposes a novel procedure-specific cardiovascular risk index. The PN-A₄CH index demonstrated good predictive ability and excellent calibration using a large national database and may enable further individualization of patient care and optimization of patient selection.

Incidence of major adverse cardiac events following non-cardiac surgery

AIMS

Major adverse cardiac events (MACE) triggered by non-cardiac surgery are prognostically important perioperative complications. However, due to often asymptomatic presentation, the incidence and timing of postoperative MACE are incompletely understood.

METHODS AND RESULTS

We conducted a prospective observational study implementing a perioperative screening for postoperative MACE [cardiovascular death (CVD), acute heart failure (AHF), haemodynamically relevant arrhythmias, spontaneous myocardial infarction (MI), and perioperative myocardial infarction/injury (PMI)] in patients at increased cardiovascular risk (≥65 years OR ≥45 years with history of cardiovascular disease) undergoing non-cardiac surgery at a tertiary hospital. All patients received serial measurements of cardiac troponin to detect asymptomatic MACE. Among 2265 patients (mean age 73 years, 43.4% women), the incidence of MACE was 15.2% within 30 days, and 20.6% within 365 days. CVD occurred in 1.2% [95% confidence interval (CI) 0.9-1.8] and in 3.7% (95% CI 3.0-4.5), haemodynamically relevant arrhythmias in 1.2% (95% CI 0.9-1.8) and in 2.1% (95% CI 1.6-2.8), AHF in 1.6% (95% CI 1.2-2.2) and in 4.2% (95% CI 3.4-5.1), spontaneous MI in 0.5% (95% CI 0.3-0.9) and in 1.6% (95% CI 1.2-2.2), and PMI in 13.2% (95% CI 11.9-14.7) and in 14.8% (95% CI 13.4-16.4) within 30 days and within 365 days, respectively. The MACE-incidence was increased above presumed baseline rate until Day 135 (95% CI 104-163), indicating a vulnerable period of 3-5 months.

CONCLUSION

One out of five high-risk patients undergoing non-cardiac surgery will develop one or more MACE within 365 days. The risk for MACE remains increased for about 5 months after non-cardiac surgery.

TRIAL REGISTRATION

https://www.clinicaltrials.gov. Unique identifier: NCT02573532.

Prognostic Value of Elevated Cardiac Troponin I After Aneurysmal Subarachnoid Hemorrhage

Object: Patients with aneurysmal subarachnoid hemorrhage (aSAH) have an increased incidence of cardiac events and short-term unfavorable neurological outcomes during the acute phase of bleeding. We studied whether troponin I elevation after ictus can predict future major adverse cardiac events (MACEs) and long-term neurological outcomes after 2 years.

Methods: Consecutive aSAH patients within 3 days of bleeding were eligible for review from a prospective observational cohort (ClinicalTrials.gov Identifier: NCT04785976). Potential predictors of future MACEs and unfavorable long-term neurological outcomes were calculated by Cox and logistic regression analyses. Additional Kaplan–Meier curves were performed.

Results: A total of 213 patients were enrolled with an average follow-up duration of 34.3 months. Individuals were divided into two groups: elevated cTnI group and unelevated cTnI group. By the last available follow-up, 20 patients had died, with an overall all-cause mortality rate of 9.4% and an annual all-cause mortality rate of 3.8%. Patients with elevated cTnI had a significantly higher risk of future MACEs (10.6 vs. 2.1%, p = 0.024, and 95% CI: 1.256–23.875) and unfavorable neurological outcomes at discharge, 3-month, 1-, 2-years, and last follow-up (p = 0.001, p < 0.001, p = 0.001, p < 0.001, and p < 0.001, respectively). In the Cox analysis for future MACE, elevated cTnI was the only independent predictor (HR = 5.980; 95% CI: 1.428–25.407, and p = 0.014). In the multivariable logistic analysis for unfavorable neurological outcomes, peak cTnI was significant (OR = 2.951; 95% CI: 1.376–6.323; p = 0.005). Kaplan–Meier analysis indicated that the elevated cTnI was correlated with future MACE (log-rank test, p = 0.007) and subsequent death (log-rank test, p = 0.004).

Conclusion: cTnI elevation after aSAH could predict future MACEs and unfavorable neurological outcomes.

Alarmin-activated B cells accelerate murine atherosclerosis after myocardial infarction via plasma cell-immunoglobulin-dependent mechanisms

AIMS

Myocardial infarction (MI) accelerates atherosclerosis and greatly increases the risk of recurrent cardiovascular events for many years, in particular, strokes and MIs. Because B cell-derived autoantibodies produced in response to MI also persist for years, we investigated the role of B cells in adaptive immune responses to MI.

METHODS AND RESULTS

We used an apolipoprotein-E-deficient (ApoE-/-) mouse model of MI-accelerated atherosclerosis to assess the importance of B cells. One week after inducing MI in atherosclerotic mice, we depleted B cells using an anti-CD20 antibody. This treatment prevented subsequent immunoglobulin G accumulation in plaques and MI-induced accelerated atherosclerosis. In gain of function experiments, we purified spleen B cells from mice 1 week after inducing MI and transferred these cells into atherosclerotic ApoE-/- mice, which greatly increased immunoglobulin G (IgG) accumulation in plaque and accelerated atherosclerosis. These B cells expressed many cytokines that promote humoural immunity and in addition, they formed germinal centres within the spleen where they differentiated into antibody-producing plasma cells. Specifically deleting Blimp-1 in B cells, the transcriptional regulator that drives their terminal differentiation into antibody-producing plasma cells prevented MI-accelerated atherosclerosis. Alarmins released from infarcted hearts were responsible for activating B cells via toll-like receptors and deleting MyD88, the canonical adaptor protein for inflammatory signalling downstream of toll-like receptors, prevented B-cell activation and MI-accelerated atherosclerosis.

CONCLUSION

Our data implicate early B-cell activation and autoantibodies as a central cause for accelerated atherosclerosis post-MI and identifies novel therapeutic strategies towards preventing recurrent cardiovascular events such as MI and stroke.

Feasibility of radical gastrointestinal tumor resection with simultaneous off-pump coronary artery bypass surgery for patients with severe heart problems: A retrospective cohort study from a single institutional database

PURPOSE

Clinical treatment of gastrointestinal neoplasms in patients with severe coronary stenosis is difficult, and it remains controversial to perform staged or simultaneous surgeries. The purpose of this study was to retrospectively analyze the feasibility and indications for simultaneous gastrointestinal tumor resection and off-pump coronary artery bypass (OPCAB) graft surgery.

METHODS

Data collected from a total of five patients, including three patients with gastric cancer and two patients with colorectal cancer, who underwent simultaneous radical cancer resection and OPCAB between September 2010 and October 2019, were retrospectively analyzed. Among these patients, one had an incomplete colonic obstruction. All patients had severe coronary stenosis, and one experienced acute heart failure before surgery. OPCAB was performed first, followed by the radical cancer resection.

RESULTS

All five patients were discharged from hospital without perioperative death, major cardiovascular events or anastomotic leakage. The mean postoperative hospital stay was 9.4 days. One patient experienced slight gastrointestinal bleeding after surgery, which improved with conservative treatment. After a mean follow-up of 39 months, two patients with gastric cancer died from tumor metastasis at 28 months and 37 months, while the remaining three patients did not have tumor recurrence or metastasis. None of the patients experienced myocardial ischemia.

CONCLUSION

It is safe and feasible to perform simultaneous OPCAB and gastrointestinal surgeries on the premise of strictly controlling the indications for patients with gastrointestinal tumors complicated with severe coronary artery stenosis.

Differences in perioperative cardiovascular outcomes in elderly male and female patients undergoing intra-abdominal surgery: a retrospective cohort study

OBJECTIVE

Perioperative cardiovascular events constitute the majority of complications in noncardiac surgery. Older and female patients have been less investigated. We aimed to evaluate differences in perioperative cardiovascular outcomes by age and sex.

METHODS

We enrolled 1079 patients (57.5 ± 17.0 years, 42.6% women) undergoing intra-abdominal surgery from July 2007 to June 2008 and compared occurrence of perioperative cardiac events by age (≥65 vs. <65 years) and sex. Multivariable logistic regression was used to investigate associations between age, sex, and outcomes.

RESULTS

Age ≥65 years was associated with perioperative myocardial infarction (MI) (odds ratio [OR] 2.9, 95% confidence interval [CI]: 1.3-6.6) and total cardiovascular events (OR 2.4, 95% CI: 1.3-4.2). Age ≥65 years was associated with higher perioperative MI risks in men (OR 4.7, 95% CI: 1.3-17.6) than in women (OR 3.1, 95% CI: 1.2-8.3). Advanced age was associated with heart failure in women (OR 13.9, 95% CI: 1.7-110.5). Female sex was a risk factor for heart failure in elderly patients (OR 4.2, 95% CI: 1.1-15.7).

CONCLUSIONS

Advanced age appeared to be associated with increased perioperative cardiac risk but differed by sex. Tailored strategies should be considered with respect to the patient's sex.

Effect of remote ischaemic preconditioning on mortality and morbidity after non-cardiac surgery: meta-analysis

BACKGROUND

Remote ischaemic preconditioning (RIPC) has been shown to have a protective role on vital organs exposed to reperfusion injury. The aim of this systematic review was to evaluate the effects of non-invasive RIPC on clinical and biochemical outcomes in patients undergoing non-cardiac surgery.

METHODS

A systematic literature search of PubMed, EMBASE, Scopus, and Cochrane databases was carried out in February 2020. RCTs investigating the effect of non-invasive RIPC in adults undergoing non-cardiac surgery were included. Meta-analyses and trial sequential analyses (TSAs) were performed on cardiovascular events, acute kidney injury, and short- and long-term mortality.

RESULTS

Some 43 RCTs including 3660 patients were included. The surgical areas comprised orthopaedic, vascular, abdominal, pulmonary, neurological, and urological surgery. Meta-analysis showed RIPC to be associated with fewer cardiovascular events in non-cardiac surgery (13 trials, 1968 patients, 421 events; odds ratio (OR) 0.68, 95 per cent c.i. 0.47 to 0.96; P = 0.03). Meta-analyses of the effect of RIPC on acute kidney injury (12 trials, 1208 patients, 211 events; OR 1.14, 0.78 to 1.69; P = 0.50; I2 = 9 per cent), short-term mortality (7 trials, 1239 patients, 65 events; OR 0.65, 0.37 to 1.12; P = 0.12; I2 = 0 per cent), and long-term mortality (4 trials, 1167 patients, 9 events; OR 0.67, 0.18 to 2.55; P = 0.56; I2 = 0 per cent) showed no significant differences for RIPC compared with standard perioperative care in non-cardiac surgery. However, TSAs showed that the required information sizes have not yet been reached.

CONCLUSION

Application of RIPC to non-cardiac surgery might reduce cardiovascular events, but not acute kidney injury or all-cause mortality, but currently available data are inadequate to confirm or reject an assumed intervention effect.

Examining Risk: A Systematic Review of Perioperative Cardiac Risk Prediction Indices

OBJECTIVE

To conduct a systematic review of published cardiac risk indices relevant to patients undergoing noncardiac surgery and to provide clinically meaningful recommendations to physicians regarding the use of these indices.

METHODS

A literature search of articles published from January 1, 1999, through December 28, 2018, was conducted in Ovid (MEDLINE), PubMed, Embase, CINAHL, and Web of Science. Publications describing models predicting risk of cardiac complications after noncardiac surgery were included and citation chaining was used to identify additional studies for inclusion.

RESULTS

Eleven risk indices involving 2,910,297 adult patients were included in this analysis. Studies varied in size, population, quality, risk of bias, outcome event definitions, risk factors identified, index outputs, accuracy, and clinical usefulness. Studies considered 6 to 83 variables to develop their models. Among the identified models, the factors with the highest predictiveness for adverse cardiac outcomes included congestive heart failure, type of surgery, creatinine, diabetes, history of stroke or transient ischemic attack, and emergency surgery. Substantial data from the large studies also supports advancing age, American Society of Anesthesiology physical status classification, functional status, and hypertension as additional risks.

CONCLUSION

The risk indices identified generally fell into two groups - those with higher accuracy for predicting a narrow range of cardiac outcomes and those with lower accuracy for predicting a broader range of cardiac outcomes. Using one index from each group may be the most clinically useful approach. Risk factors identified varied widely among studies. In addition to judicious use of predictive indices, reasoned clinical judgment remains indispensable in assessing perioperative cardiac risk.

The administration of dexmedetomidine changes microRNA expression profiling of rat hearts

BACKGROUND

Dexmedetomidine is widely used for perioperative and ICU patients. microRNAs (miRNAs) function as regulators of gene expression. The aim of the study was to assay expression profiling of microRNA in rat hearts following administration of dexmedetomidine.

METHODS

In this study 6 rats were randomly divided into two groups (n = 3): dexmedetomidine group and control group. The rats of dexmedetomidine group were intraperitoneally given dexmedetomidine in a dose of 100 μg/kg whereas the rats in control group were administered normal saline intraperitoneally. The hearts were excised 30 min after the administration of dexmedetomidine or normal saline under anesthesia. The samples were analyzed for differentially expressed microRNAs with Exiqon miRNA Array. The differentially expressed microRNAs were confirmed by using qRT-PCR. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to find the target genes and signaling pathways of the aberrantly expressed miRNAs.

RESULTS

Six microRNAs were identified to be significantly expressed, among of which, five microRNAs (miRNA-434-3p, miRNA-3596d, miRNA-496-5p, miRNA-7a-2-3p and miRNA-702-3p) were up-regulated and 1 microRNA (miRNA-208b-3p) down-regulated compared to those of control group. The aberrantly expressed microRNAs were further validated by Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). GO and KEGG analyses were used to identify target genes and the signaling pathways.

CONCLUSIONS

The use of dexmedetomidine is associated with differentially expressed microRNAs which may be involved in cardioprotection following administration of dexmedetomidine.

A feasibility study to investigate post-operative oxygen consumption (POpOC) after colorectal surgery requiring bowel resection

BACKGROUND

Oxygen consumption after surgery is increased in response to the tissue trauma sustained intra-operatively and the subsequent systemic inflammatory response that ensues. The cardio-respiratory system must match the tissue oxygen and metabolic requirements; otherwise, peri-operative complications may occur. Existing data is several decades old. The primary objective of this feasibility study was to determine the ease of recruiting participants and collecting relevant data to assess the extent and duration of increased oxygen consumption and post-operative complications after major abdominal surgery in contemporaneous times.

METHODS

One hundred patients scheduled for elective colorectal surgery requiring a bowel resection were screened to test specific feasibility criteria relating to ease of recruitment, duration of post-operative stay, ease of data collection, and drop-out rates. A calibrated metabolic cart was used to obtain unblinded pre-operative resting oxygen consumption recordings. The metabolic cart was then used to obtain post-operative oxygen consumption readings on days 1 to 5 as long as the participant remained as an inpatient. At the time of the oxygen consumption reading, a Post-Operative Morbidity Survey score (POMS) was calculated. Feasibility outcomes chosen a priori were that at least one participant would be recruited every 2 weeks from the pre-admission colorectal clinic, at least 10% of potential subjects screened would be enrolled, at least 80% of recruited participants would have a minimum post-operative stay of 2 nights, a minimum of 3 consecutive days of oxygen consumption data would be collected for each subject, at least 8 of 9 POMS score domains would be completed per participant per day and the drop-out rate would be no greater than 10%. We deemed that screening 100 patients would be sufficient to test our feasibility outcomes.

RESULTS

Twelve participants completed the protocol. All pre-specified feasibility criteria were met. No increase in post-operative oxygen consumption was observed in this feasibility cohort.

CONCLUSIONS

The protocol and experiences gained from this feasibility study could be used to plan a larger study to better define changes in post-operative oxygen consumption after major abdominal surgery utilizing current surgical techniques.

Application of transthoracic echocardiography in patients receiving intermediate- or high-risk noncardiac surgery

Background

Cardiovascular events are the leading cause of perioperative complications among patients undergoing noncardiac surgery. However, the role of echocardiography for preoperative cardiac risk stratification prior to major noncardiac surgery is still controversial.

Methods

This retrospective study included a total of 1453 patients (51% male; age, 67 ± 16) who underwent intermediate- or high-risk major abdominal surgery or orthopedic surgery at two medical centers in South Taiwan between February 2013 and June 2016. All patients underwent preoperative transthoracic echocardiography (TTE). All of the included patients were followed up for 56 days after surgery. The primary endpoints were major adverse events (MAEs), i.e., all-cause mortality and major adverse cardiovascular-cerebral events (MACCEs).

Results

A total of 35 patients (2.4%) reached the primary endpoint: 24 patients (1.6%) died, and 17 patients (1.2%) had MACCEs. Patients with postsurgery MAEs had higher average E/e’ values, a lower Left ventricular (LV) ejection fraction, and higher prevalence of significant mitral regurgitation (MR) and moderate-advanced chronic kidney disease (CKD). Multivariate analysis showed that the modified Lee index and significant MR were independent prognostic predictors of MAEs.

Conclusion

Preoperative identification of significant MR on TTE is associated with increased MAEs at 56 days compared with that predicted by the modified Lee index alone in patients undergoing intermediate- or high-risk noncardiac surgery.

Perioperative acute myocardial infarction rate in chronic renal disease patients undergoing orthopedic surgery: Is there any difference between dialyzed and nondialyzed patients?

Background

The incidence of acute myocardial infarction (AMI) in healthy patients undergoing noncardiac surgery is <1%. When patients with chronic kidney disease (CKD) undergo orthopedic surgery, AMI incidence can be expected to be relatively high. However, data on a population-wide scale is lacking.

Objective

To investigate AMI incidence in patients with CKD (with and without dialysis) undergoing orthopedic surgery.

Design

A population-based study covering the period from January 1, 1997, to December 31, 2011.

Setting

Data from the Taiwan National Health Insurance Research Database.

Participants

Participants were 219,195 patients with CKD who underwent surgery between January 1, 1997, and December 31, 2011.

Results

AMI occurred in 2,708 participants (1.24%). The AMI incidence rate in the dialyzed group was 1.52%, which was higher than that in the nondialyzed group after propensity score matching. Dialysis (odds ratio [OR]: 1.79; 95% confidence interval [CI]: 1.62–1.98), male (OR: 1.42; 95% CI: 1.28–1.57), diabetes mellitus (OR: 1.61; 95% CI: 1.44–1.80), hyperlipidemia (OR: 1.88; 95% CI: 1.68–2.11), old myocardial infarction (OR: 18.87; 95% CI: 16.26–1.21.90), and cerebral vascular disease (CVA) (OR: 1.29; 95% CI: 1.30–1.47) were all associated with AMI in the patients with CKD.

Conclusions

The AMI risk was higher in the patients with CKD undergoing orthopedic surgery than in the general population, and the dialyzed group had a higher risk of AMI than did the nondialyzed group.

Predictive Factors of Postoperative Blood Pressure Abnormalities Following a Minor-to-Moderate Surgery

Myocardial ischemic events after non-cardiac surgery is still a serious problem, especially in older, high-risk patients. However, the prevalence and risk factors of blood pressure (BP) abnormalities, which may possibly lead to myocardial ischemic attack, have not been reported. Our aim is to elucidate predictive factors of postoperative BP abnormalities following a minor-to-moderate surgery, employing preoperative left ventricular diastolic function. Patients who underwent cardiac echocardiogram examination and received oral and maxillofacial surgery under general anesthesia were enrolled. The echocardiographic parameters of diastolic function were compared between patients who had postoperative BP abnormalities (hypertension-systolic blood pressure [SBP] ≥ 170 mmHg-or hypotension-SBP < 80 mmHg-episode) that required therapeutic interventions until 7 days after surgery and those who had no BP abnormalities. Of the 173 patients analyzed, 25 (14.4%) had BP abnormalities. BP abnormalities patients were older, having a larger proportion of diabetes mellitus, lower E/A ratio and e', and larger E/e' and left atrial dimension than those without BP abnormalities. Subanalyses revealed that the independent risk factors responsible for hypertension episodes (14 patients) were the mean e' (odd ratio [OR]: 0.434; 95% confidence interval [CI]: 0.229-0.824), diabetes mellitus (OR: 5.018; 95% CI: 1.030-24.436), SBP at hospitalization (OR: 1.099; 95% CI: 1.036-1.165), and operation time (hour; OR: 1.326; 95%CI: 1.109-1.586), while hypotension episodes (11 patients) were associated solely with operation time (OR: 1.206; 95% CI: 1.046-1.391). In conclusion, left ventricular diastolic dysfunction, increased insulin resistance, boosted SBP at hospitalization, and prolonged operation should be taken into consideration as risk factors of postoperative BP abnormalities, especially hypertension, following minor-to-moderate surgery.

Facility-level association of preoperative stress testing and postoperative adverse cardiac events

Background

Despite limited indications, preoperative stress testing is often used prior to non-cardiac surgery. Patient-level analyses of stress testing and outcomes are limited by case mix and selection bias. Therefore, we sought to describe facility-level rates of preoperative stress testing for non-cardiac surgery, and to determine the association between facility-level preoperative stress testing and postoperative major adverse cardiac events (MACE).

Methods

We identified patients undergoing non-cardiac surgery within 2 years of percutaneous coronary intervention in the Veterans Affairs (VA) Health Care System, from 2004 to 2011, facility-level rates of preoperative stress testing and postoperative MACE (death, myocardial infarction (MI) or revascularisation within 30 days). We determined risk-standardised facility-level rates of stress testing and postoperative MACE, and the relationship between facility-level preoperative stress testing and postoperative MACE.

Results

Among 29 937 patients undergoing non-cardiac surgery at 131 VA facilities, the median facility rate of preoperative stress testing was 13.2% (IQR 9.7%–15.9%; range 6.0%–21.5%), and 30-day postoperative MACE was 4.0% (IQR 2.4%–5.4%). After risk standardisation, the median facility-level rate of stress testing was 12.7% (IQR 8.4%–17.4%) and postoperative MACE was 3.8% (IQR 2.3%–5.6%). There was no correlation between risk-standardised stress testing and composite MACE at the facility level (r=0.022, p=0.81), or with individual outcomes of death, MI or revascularisation.

Conclusions

In a national cohort of veterans undergoing non-cardiac surgery, we observed substantial variation in facility-level rates of preoperative stress testing. Facilities with higher rates of preoperative stress testing were not associated with better postoperative outcomes. These findings suggest an opportunity to reduce variation in preoperative stress testing without sacrificing patient outcomes

Etiology of Acute Coronary Syndrome after Noncardiac Surgery

BACKGROUND

The objective of this investigation was to determine the etiology of perioperative acute coronary syndrome with a particular emphasis on thrombosis versus demand ischemia.

METHODS

In this retrospective cohort study, adult patients were identified who underwent coronary angiography for acute coronary syndrome within 30 days of noncardiac surgery at a major tertiary hospital between January 2008 and July 2015. Angiograms were independently reviewed by two interventional cardiologists who were blinded to clinical data and outcomes. Acute coronary syndrome was classified as ST-elevation myocardial infarction, non-ST-elevation myocardial infarction, or unstable angina; myocardial infarctions were adjudicated as type 1 (plaque rupture), type 2 (demand ischemia), or type 4b (stent thrombosis).

RESULTS

Among 215,077 patients screened, 146 patients were identified who developed acute coronary syndrome: 117 were classified as non-ST-elevation myocardial infarction (80.1%); 21 (14.4%) were classified as ST-elevation myocardial infarction, and 8 (5.5%) were classified as unstable angina. After coronary angiography, most events were adjudicated as demand ischemia (type 2 myocardial infarction, n = 106, 72.6%) compared to acute coronary thrombosis (type 1 myocardial infarction, n = 37, 25.3%) and stent thrombosis (type 4B, n = 3, 2.1%). Absent or only mild, nonobstructive coronary artery disease was found in 39 patients (26.7%). In 14 patients (9.6%), acute coronary syndrome was likely due to stress-induced cardiomyopathy. Aggregate 30-day and 1-yr mortality rates were 7 and 14%, respectively.

CONCLUSIONS

The dominant mechanism of perioperative acute coronary syndrome in our cohort was demand ischemia. A subset of patients had no evidence of obstructive coronary artery disease, but findings were consistent with stress-induced cardiomyopathy.

Perioperative beta-blockers for preventing surgery-related mortality and morbidity

BACKGROUND

Randomized controlled trials have yielded conflicting results regarding the ability of beta-blockers to influence perioperative cardiovascular morbidity and mortality. Thus routine prescription of these drugs in unselected patients remains a controversial issue.

OBJECTIVES

The objective of this review was to systematically analyse the effects of perioperatively administered beta-blockers for prevention of surgery-related mortality and morbidity in patients undergoing any type of surgery while under general anaesthesia.

SEARCH METHODS

We identified trials by searching the following databases from the date of their inception until June 2013: MEDLINE, Embase , the Cochrane Central Register of Controlled Trials (CENTRAL), Biosis Previews, CAB Abstracts, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Derwent Drug File, Science Citation Index Expanded, Life Sciences Collection, Global Health and PASCAL. In addition, we searched online resources to identify grey literature.

SELECTION CRITERIA

We included randomized controlled trials if participants were randomly assigned to a beta-blocker group or a control group (standard care or placebo). Surgery (any type) had to be performed with all or at least a significant proportion of participants under general anaesthesia.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data from all studies. In cases of disagreement, we reassessed the respective studies to reach consensus. We computed summary estimates in the absence of significant clinical heterogeneity. Risk ratios (RRs) were used for dichotomous outcomes, and mean differences (MDs) were used for continuous outcomes. We performed subgroup analyses for various potential effect modifiers.

MAIN RESULTS

We included 88 randomized controlled trials with 19,161 participants. Six studies (7%) met the highest methodological quality criteria (studies with overall low risk of bias: adequate sequence generation, adequate allocation concealment, double/triple-blinded design with a placebo group, intention-to-treat analysis), whereas in the remaining trials, some form of bias was present or could not be definitively excluded (studies with overall unclear or high risk of bias). Outcomes were evaluated separately for cardiac and non-cardiac surgery.CARDIAC SURGERY (53 trials)We found no clear evidence of an effect of beta-blockers on the following outcomes.• All-cause mortality: RR 0.73, 95% CI 0.35 to 1.52, 3783 participants, moderate quality evidence.• Acute myocardial infarction (AMI): RR 1.04, 95% CI 0.71 to 1.51, 3553 participants, moderate quality evidence.• Myocardial ischaemia: RR 0.51, 95% CI 0.25 to 1.05, 166 participants, low quality evidence.• Cerebrovascular events: RR 1.52, 95% CI 0.58 to 4.02, 1400 participants, low quality evidence.• Hypotension: RR 1.54, 95% CI 0.67 to 3.51, 558 participants, low quality evidence.• Bradycardia: RR 1.61, 95% CI 0.97 to 2.66, 660 participants, low quality evidence.• Congestive heart failure: RR 0.22, 95% CI 0.04 to 1.34, 311 participants, low quality evidence.Beta-blockers significantly reduced the occurrence of the following endpoints.• Ventricular arrhythmias: RR 0.37, 95% CI 0.24 to 0.58, number needed to treat for an additional beneficial outcome (NNTB) 29, 2292 participants, moderate quality evidence.• Supraventricular arrhythmias: RR 0.44, 95% CI 0.36 to 0.53, NNTB five, 6420 participants, high quality evidence.• On average, beta-blockers reduced length of hospital stay by 0.54 days (95% CI -0.90 to -0.19, 2450 participants, low quality evidence).NON-CARDIAC SURGERY (35 trials)Beta-blockers significantly increased the occurrence of the following adverse events.• All-cause mortality: RR 1.25, 95% CI 1.00 to 1.57, 11,413 participants, low quality of evidence, number needed to treat for an additional harmful outcome (NNTH) 167.• Hypotension: RR 1.50, 95% CI 1.38 to 1.64, NNTH 16, 10,947 participants, high quality evidence.• Bradycardia: RR 2.23, 95% CI 1.48 to 3.36, NNTH 21, 11,033 participants, moderate quality evidence.We found a potential increase in the occurrence of the following outcomes with the use of beta-blockers.• Cerebrovascular events: RR 1.59, 95% CI 0.93 to 2.71, 9150 participants, low quality evidence.Whereas no clear evidence of an effect was found when all studies were analysed, restricting the meta-analysis to low risk of bias studies revealed a significant increase in cerebrovascular events with the use of beta-blockers: RR 2.09, 95% CI 1.14 to 3.82, NNTH 265, 8648 participants.Beta-blockers significantly reduced the occurrence of the following endpoints.• AMI: RR 0.73, 95% CI 0.61 to 0.87, NNTB 76, 10,958 participants, high quality evidence.• Myocardial ischaemia: RR 0.51, 95% CI 0.34 to 0.77, NNTB nine, 978 participants, moderate quality evidence.• Supraventricular arrhythmias: RR 0.73, 95% CI 0.57 to 0.94, NNTB 112, 8744 participants, high quality evidence.We found no clear evidence of an effect of beta-blockers on the following outcomes.• Ventricular arrhythmias: RR 0.68, 95% CI 0.31 to 1.49, 476 participants, moderate quality evidence.• Congestive heart failure: RR 1.18, 95% CI 0.94 to 1.48, 9173 participants, moderate quality evidence.• Length of hospital stay: mean difference -0.45 days, 95% CI -1.75 to 0.84, 551 participants, low quality evidence.

AUTHORS' CONCLUSIONS

According to our findings, perioperative application of beta-blockers still plays a pivotal role in cardiac surgery, as they can substantially reduce the high burden of supraventricular and ventricular arrhythmias in the aftermath of surgery. Their influence on mortality, AMI, stroke, congestive heart failure, hypotension and bradycardia in this setting remains unclear.In non-cardiac surgery, evidence shows an association of beta-blockers with increased all-cause mortality. Data from low risk of bias trials further suggests an increase in stroke rate with the use of beta-blockers. As the quality of evidence is still low to moderate, more evidence is needed before a definitive conclusion can be drawn. The substantial reduction in supraventricular arrhythmias and AMI in this setting seems to be offset by the potential increase in mortality and stroke.

Which factor is the most effective one in metabolic Sydrome on the outcomes after coronary artery bypass graft surgery? A cohort study of 5 Years

Background

Metabolic Syndrome and diabetes mellitus are risk factors for cardiovascular disease. However, the effects of Metabolic Syndrome with or without diabetes on perioperative and long-term morbidity and mortality after Coronary Artery Bypass Graft remain unclear.

Methods

An retrospective study was performed on 1166 patients who received isolated primary Coronary Artery Bypass Graft in Fuwai hospital. They were divided into three groups: control, Metabolic Syndrome of three factors together with diabetes and Metabolic Syndrome of three factors without diabetes (n = 868, 76 and 222 respectively). Analysis of variance, Chi-rank test, Fisher’s exact test, Log-rank test, Cox and Logistic regression models were used for data processing. Outcomes were postoperative and 5-year survival and morbidities.

Results

There were no significant differences between groups in in-hospital postoperative complications, epinephrine use, stroke, atrial fibrillation, renal failure, coma, myocardial infarction and repeated revascularization. Patients in the Metabolic Syndrome with diabetes, Metabolic Syndrome without diabetes and control groups, respectively, showed significant difference in perioperative Major Adverse Cerebral Cardiovascular Events (30.3% vs. 21.2%, 16.7%, P = 0.0071) and mortality (11.8% vs. 2.7%, 3.11%, P = 0.0003). The Metabolic Syndrome with diabetes group had higher rates of perioperative mortality than Metabolic Syndrome without diabetes (P = 0.0017, P of Fisher Test = 0.0039). Compared with non-diabetic patients with Metabolic Syndrome, those with Metabolic Syndrome and diabetes had increased long-term mortality (Adjusted HR: 4.3; 95% CI: 1.4–13.3; P = 0.0113) and Major Adverse Cerebral Cardiovascular Events (Adjusted OR: 1.7; 95% CI: 1.0–2.8; P = 0.048). Control and non-diabetic Metabolic Syndrome groups did not differ in long-term mortality but controls had lower rates of Major Adverse Cerebral Cardiovascular Events (Adjusted OR: 0.79; 95% CI: 0.64–0.98; P = 0.0329).

Conclusions

There were significance differences between the three groups in perioperative Major Adverse Cerebral Cardiovascular Events and mortality after Coronary Artery Bypass Graft. Compared with non-diabetic Metabolic Syndrome patients, patients with Metabolic Syndrome and diabetes had higher long-term Major Adverse Cerebral Cardiovascular Events and mortality. While patients free of MetS and diabetes were associated with lower incidence of long-term Major Adverse Cerebral Cardiovascular Events after Coronary Artery Bypass Graft.

Anesthetic management of off-pump simultaneous coronary artery bypass grafting and lobectomy: Case report and literature review

RATIONALE

Survey data show approximately 10% patients with lung cancer may present concomitant coronary heart disease. Simultaneous surgery is a challenge for anesthetist. We review our experience in the anesthesia with 5 patients who required simultaneous off-pump coronary artery bypass grafting (OPCABG) and pulmonary resection for lung cancer.

PATIENT CONCERNS

Between 2014 and 2016, 5 patients with ASA (American Society of Anesthesiologists) grade II or III, underwent combined OPCABG and lung resection in the first Affiliated Hospital, Zhejiang University School of Medicine.

DIAGNOSES

All five patients were diagnosed with coronary heart disease and peripheral pulmonary carcinoma INTERVENTIONS:: Five patients received general anesthesia with double-lumen endobronchial tube for lung separation. The anesthetics were used, which caused slight hemodynamic fluctuations during induction of anesthesia; while during the maintenance of anesthesia, supplemented by Dexmedetomidine, the drug doses were titrated according to the depth of anesthesia. Guided by cardiac index (CI), stroke volume variation (SVV) and oxygen delivery (DO2), different strategies were taken at the different stage of surgery, during lung resection, SVV was kept about 13% to 15%, and less than 10% during OPCABG.

OUTCOMES

Five patients were transferred to intensive care unit (ICU) with intubation after surgery, duration of ventilation was 10 to 18 hours, and length of ICU stay and hospital stay were 1.8 to 2.5 ds and 11 to 16 ds, respectively. All of patients were discharged with not any perioperative complication.

LESSONS

In summary, anesthetists should focus on the maintenance of the balance between oxygen supply and demanding, which was achieved by close monitoring, titration of anesthetics and goal-directed fluid therapy during surgical procedures.

Derivation and Validation of a Geriatric-Sensitive Perioperative Cardiac Risk Index

Background

Surgical patients aged 65 and over face a higher risk of cardiac complications from noncardiac surgery. The Revised Cardiac Risk Index (RCRI) and the Gupta Myocardial Infarction or Cardiac Arrest (MICA) calculator are widely used to predict this risk, but they are not specifically designed to predict MICA in geriatric patients. Our hypothesis is that a new geriatric‐sensitive index, derived from geriatric data, will capture this population's unique response to risk factors.

Methods and Results

The model was developed using the NSQIP (National Surgical Quality Improvement Program) 2013 geriatric cohort (N=584,931) (210,914 age ≥65) and validated on the NSQIP 2012 geriatric cohort (N= 485,426) (172,905 age ≥65). Least Angle Shrinkage and Selection Operator regression was used for initial variable selection. The Geriatric‐Sensitive Cardiac Risk Index (GSCRI) was then evaluated in the 2012 data set. The area under the curve (AUC) was compared among the GSCRI, RCRI, and Gupta MICA in the 2012 data set. The GSCRI had an AUC of 0.76 in the validation cohort among geriatric patients. When the Gupta MICA was tested on geriatric patients in the validation cohort, a significant deterioration (≈17%) was noted, as well as a significant underestimation of the risk. The GSCRI AUC of 0.76 in the geriatric subset was significantly greater (P<0.001) than those in the RCRI (AUC=0.63) or Gupta MICA (AUC=0.70) models, outperforming the RCRI and Gupta MICA models in geriatric patients by 13% and 6%, respectively, with a ΔAUC and P‐value of 0.13 (P<0.001), and 0.06 (P<0.001).

Conclusions

The GSCRI is a significantly better predictor of cardiac risk in geriatric patients undergoing noncardiac surgery.

Triple Antithrombotic Therapy and Outcomes in Post-PCI Patients Undergoing Non-cardiac Surgery

BACKGROUND

Triple therapy, or the use of anticoagulants with dual antiplatelet therapy (DAPT), is often used to protect against ischemic events in post-percutaneous coronary intervention (PCI) patients with indications for anticoagulation, but is associated with increased bleeding. As both ischemic and bleeding risks increase in the perioperative period, the impact of triple therapy may be especially pronounced in patients undergoing surgery. Outcomes in this population are currently unknown.

METHODS

We identified patients undergoing non-cardiac surgeries within 2 years of PCI in Veterans Affairs hospitals from 2004 to 2012. We compared perioperative major adverse cardiovascular and cerebrovascular events (MACCE: mortality, myocardial infarction, stroke, revascularization) and bleeding events (in-hospital bleeding, transfusion) between surgeries in patients prescribed triple therapy and DAPT, adjusting for clinical, demographic, and operative characteristics.

RESULTS

Among 7811 surgeries, 391 (5.0 %) occurred in patients receiving triple therapy. 44 (11.3 %) MACCE and 107 (27.4 %) bleeding events occurred with surgeries in triple therapy patients, compared to 366 (4.9 %) MACCE and 980 (13.2 %) bleeding events in DAPT patients. After adjustment, surgery in triple therapy patients was associated with higher rates of MACCE [odds ratio (OR) 1.65, 95 % confidence interval (CI) 1.16-2.34] or bleeding (OR 1.52, 95 % CI 1.17-1.99) as compared to surgery in DAPT patients.

CONCLUSIONS

One in twenty post-PCI patients undergoing non-cardiac surgery were on triple therapy. Surgery in these patients was associated with higher MACCE and bleeding events compared to surgery in patients on DAPT, independent of clinical and operative characteristics. These findings identify a high-risk population for surgery, which may warrant increased surveillance for adverse perioperative events.

The effects of dexmedetomidine preconditioning on aged rat heart of ischaemia reperfusion injury

To assess the effect of dexmedetomidine on myocardial ischemia reperfusion injury in vivo aged rat heart. 40 healthy male, 20month aged, 350-400g Sprague-Dawley rats. Rats were divided into four groups randomly(n=10): group of ischemic preconditioning(IP group), group of Sham(CS group), group of dexmedetomidine(DP group), Ischemia-reperfusion injury group(IR group). The date of HR and ±dp/dtmax were detected before and after the occur of ischemia reperfusion. Superoxide dismutase (SOD) and malondialdehyde (MDA) activity were recorded; myocardial infarct size was calculated at the end of reperfusion. HR in each group decreased after thoracotomy. Compared with CS group, the HR in IR group reduced significantly (P<0.05). After given dexmedetomidine, HR in the DP group began to decrease significantly. Left heart function in IR group compared with the CS group showed that a statistically reduce of left ventricular function happened in IR group. ±dp/dtmax of the IR groups compared with the CS group were increased. SOD activity reduced and MDA in myocardial tissue homogenates increased in IR group (P<0.05); SOD activity in DP group compared with IR group deduced, MDA increased (P<0.05). Dexmedetomidine preconditioning can effectively reduce ischemia reperfusion injury of the aged rat in vivo, have a protective effect on aged rat heart.

Postoperative Cardiac Ischemia Detection by Continuous 12-Lead Electrocardiographic Monitoring in Vascular Surgery Patients: A Prospective, Observational Study

OBJECTIVES

Elderly patients undergoing vascular surgery are at major risk for perioperative cardiac complications. The authors investigated continuous electrocardiographic Holter monitoring in a postoperative setting to determine the degree of postoperative ischemic load and its possible associations with perioperative myocardial infarction.

DESIGN

A prospective, observational study.

SETTING

One university hospital.

PARTICIPANTS

The study comprised 51 patients aged 65 years or older undergoing peripheral arterial surgery.

INTERVENTIONS

Continuous electrocardiographic monitoring with a Holter device was started postoperatively and continued for 72 hours or until discharge. Postural changes were recorded using a 3-axis accelerometer. Standard 12-lead electrocardiography, high-sensitive troponin T measurements, and an inquiry of ischemic symptoms were performed 4 times perioperatively.

MEASUREMENTS AND MAIN RESULTS

The primary outcomes were ischemic load (area under the function of ischemic ST-segment deviation and ischemic time) and perioperative myocardial infarction. During 3,262.7 patient-hours of monitoring, 17 patients (33.3%) experienced 608 transient ischemic events, all denoted by ST-segment depression. Of these 17 patients, 5 experienced perioperative myocardial infarction. The mean ischemic load in all patients was 913.2±2,797.3 µV×minute. Ischemic load predicted perioperative myocardial infarction, with an area under receiver operating characteristics curve (95% confidence interval) of 0.87 (0.75-0.99). Ischemic changes occurred most frequently during hours 24 to 60 of monitoring. Ischemia was asymptomatic in 14 of 17 patients (82.4%).

CONCLUSION

Postoperative myocardial ischemia was common in peripheral vascular surgery patients and may progress to perioperative myocardial infarction. Ischemic load was a good predictor of perioperative myocardial infarction. Ambulatory electrocardiographic monitoring solutions for continuous postoperative ischemia detection are warranted in the surgical ward.

Canadian Cardiovascular Society Guidelines on Perioperative Cardiac Risk Assessment and Management for Patients Who Undergo Noncardiac Surgery

The Canadian Cardiovascular Society Guidelines Committee and key Canadian opinion leaders believed there was a need for up to date guidelines that used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system of evidence assessment for patients who undergo noncardiac surgery. Strong recommendations included: 1) measuring brain natriuretic peptide (BNP) or N-terminal fragment of proBNP (NT-proBNP) before surgery to enhance perioperative cardiac risk estimation in patients who are 65 years of age or older, are 45-64 years of age with significant cardiovascular disease, or have a Revised Cardiac Risk Index score ≥ 1; 2) against performing preoperative resting echocardiography, coronary computed tomography angiography, exercise or cardiopulmonary exercise testing, or pharmacological stress echocardiography or radionuclide imaging to enhance perioperative cardiac risk estimation; 3) against the initiation or continuation of acetylsalicylic acid for the prevention of perioperative cardiac events, except in patients with a recent coronary artery stent or who will undergo carotid endarterectomy; 4) against α₂ agonist or β-blocker initiation within 24 hours before surgery; 5) withholding angiotensin-converting enzyme inhibitor and angiotensin II receptor blocker starting 24 hours before surgery; 6) facilitating smoking cessation before surgery; 7) measuring daily troponin for 48 to 72 hours after surgery in patients with an elevated NT-proBNP/BNP measurement before surgery or if there is no NT-proBNP/BNP measurement before surgery, in those who have a Revised Cardiac Risk Index score ≥1, age 45-64 years with significant cardiovascular disease, or age 65 years or older; and 8) initiating of long-term acetylsalicylic acid and statin therapy in patients who suffer myocardial injury/infarction after surgery.

Signal Quality Analysis of Ambulatory Electrocardiograms to Gate False Myocardial Ischemia Alarms

OBJECTIVE

The objective of this study is to propose and validate an alarm gating system for a myocardial ischemia monitoring system that uses ambulatory electrocardiogram. The PeriOperative ISchemic Evaluation study recommended the selective administration of β blockers to patients at risk of cardiac events following noncardiac surgery. Patients at risk are identified by monitoring ST segment deviations in the electrocardiogram (ECG); however, patients are encouraged to ambulate to improve recovery, which deteriorates the signal quality of the ECG leading to false alarms.

METHODS

The proposed alarm gating system computes a signal quality index (SQI) to quantify the ECG signal quality and rejects alarms with a low SQI. The system was validated by artificially contaminating ECG records with motion artifact records obtained from the long-term ST database and MIT-BIH noise stress test database, respectively.

RESULTS

Without alarm gating, the myocardial ischemia monitoring system attained a Precision of 0.31 and a Recall of 0.78. The alarm gating improved the Precision to 0.58 with a reduction of Recall to 0.77.

CONCLUSION

The proposed system successfully gated false alarms with future work exploring the misidentification of fiducial points by myocardial ischemia monitoring systems.

SIGNIFICANCE

The reduction of false alarms due to the proposed system will decrease the incidence of the alarm fatigue condition typically found in clinicians. Alarm fatigue condition was rated as the top patient safety hazard from 2012 to 2015 by the Emergency Care Research Institute.

Role of prophylactic coronary revascularisation in improving cardiovascular outcomes during non-cardiac surgery: A narrative review

Coronary revascularisation has been a topic of debate for over three decades in patients undergoing high-risk non-cardiac surgery. The paradigm shifted from routine coronary angiography toward stress test guided decision-making based on larger randomised trials. However, this paradigm is challenged by relatively newer data where routine coronary angiography and revascularisation is shown to improve perioperative cardiovascular outcomes. We review major studies performed over a long period including more contemporary data with regard to the 2014 American College of Cardiology/American Heart Association as well as 2014 European Society of Cardiology guideline on perioperative cardiovascular evaluation of patients undergoing non-cardiac surgery.

Diagnosing Perioperative Myocardial Infarction in Cardioth oracic and Vascular Surgery

Patients undergoing cardiac and high-risk noncardiac surgery have a high incidence of perioperative myocardial infarction. The early diagnosis of perioperative myocardial injury in these patients is complicated. In the perioperative period, there is a high incidence of nonspecific electrocardiographic changes and cardiac biomarker release. It is becoming increasingly imortant to differentiate myocardial necrosis from nonspecific changes because of the need for early intervention and the poential long term implications of a perioperative myocardial event. Although sensitive and specific assays to assess myoardial damage have been developed, specific thresholds to establish the occurrence a significant perioperative event have not been firmly defined. This review will attempt to outline the current evidence supporting the use of clinical symptoms, electrocardiographic changes, and cardiac biomarkers in the diagnosis of perioperative myocardial infarction and the longerm implication of these findings.

Protecting the Heart with Cardiac Medication in Patients with Left Ventricular Dysfunction Undergoing Major Noncardiac Vascular Surgery

Patients with left ventricular dysfunction who are undergoing major noncardiac vascular surgery are at increased risk of adverse postoperative events. We sought to evaluate whether perioperative medication use, including angiotensin-converting enzyme (ACE) inhibitors,b-blockers, statins, and aspirin, was associated with a reduced incidence of postoperative in-hospital mortality in these high-risk patients. The study enrolled 511 patients with left ventricular dysfunction (left ventricular ejection fraction <30%) who were undergoing major noncardiac vascular surgery. Cardiac risk factors and medication use were noted before surgery. Preoperative dobutamine stress echocardiography (DSE) was performed to identify patients with stress-induced myocardial ischemia. The end point was postoperative in-hospital mortality. Univariate and multivariate logistic regression analyses were performed to evaluate the relation between perioperative medication use and mortality. The mean age of the study population was 64 ± 11 years, and 75% were men. Perioperative use of ACE inhibitors, b-blockers, statins, and aspirin was recorded in 215 (48%), 139 (27%), 107 (21%), and 125 patients (24%), respectively. Stress-induced myocardial ischemia occurred in 82 patients (16%). Sixty-four patients (13%) died. Perioperative use of ACE inhibitors (odds ratio [OR], 0.33; 95% confidence interval [CI], 0.12-0.91), b-blockers (OR, 0.03; 95% CI, 0.01-0.26), statins (OR, 0.06; 95% CI, 0.01-0.53), and aspirin (OR, 0.13; 95% CI, 0.03-0.55), was significantly associated with a reduced incidence of mortality, after adjusting for cardiac risk factors and DSE results. In conclusion, the present study showed that the perioperative use of ACE inhibitors,b-blockers, statins, and aspirin is independently associated with a reduced incidence of in-hospital mortality in patients with left ventricular dysfunction who are undergoing major noncardiac vascular surgery.

How to Reliably Detect Ischemia in the Intensive Care Unit and Operating Room

Detection of myocardial ischemia in the perioperative period is important because it allows for intervention that may prevent progression of ischemia to myocardial infarction. Perioperative ischemia is also an important predictor of adverse cardiovascular outcomes. Patients should first be stratified according to their risk of having cardiovascular disease by identifying major, intermediate, and minor predictors of adverse cardiovascular outcome. Electrocardiographic (ECG) monitoring for ischemia is inexpensive and noninvasive, but may not be applicable to all patients and is not perfectly sensitive or specific. Modern operating room monitors can automate ST segment monitoring and be set to alarm if changes occur. Increases in central venous pressure and pulmonary artery pressure can be caused by myocardial ischemia, but have been shown to be very insensitive compared to ECG. Also, detection of these hemodynamic changes requires insertion of invasive monitoring devices. Transesophageal echocardiography can be used to detect myocardial ischemia by identifying changes in regional wall motion. These transesophageal echocardiography changes occur sooner and more frequently than ECG changes, but require greater knowledge and skill to properly interpret.

Nitrates for the prevention of cardiac morbidity and mortality in patients undergoing non-cardiac surgery

BACKGROUND

Cardiac complications are not uncommon in patients undergoing non-cardiac surgery, especially in patients with coronary artery disease (CAD) or at high risk of CAD. Perioperative cardiac complications can lead to mortality and morbidity, as well as higher costs for patient care. Nitrates, which are among the most commonly used cardiovascular drugs, perform the function of decreasing cardiac preload while improving cardiac blood perfusion. Sometimes, nitrates are administered to patients undergoing non-cardiac surgery to reduce the incidence of cardiac complications, especially for patients with CAD. However, their effects on patients' relevant outcomes remain controversial.

OBJECTIVES

• To assess effects of nitrates as compared with other interventions or placebo in reducing cardiac risk (such as death caused by cardiac factors, angina pectoris, acute myocardial infarction, acute heart failure and cardiac arrhythmia) in patients undergoing non-cardiac surgery.• To identify the influence of different routes and dosages of nitrates on patient outcomes.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and the Chinese BioMedical Database until June 2014. We also searched relevant conference abstracts of important anaesthesiology or cardiology scientific meetings, the database of ongoing trials and Google Scholar.We reran the search in January 2016. We added three potential new studies of interest to the list of 'Studies awaiting classification' and will incorporate them into our formal review findings for the review update.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing nitrates versus no treatment, placebo or other pharmacological interventions in participants (15 years of age and older) undergoing non-cardiac surgery under any type of anaesthesia.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by Cochrane. Two review authors selected trials, extracted data from included studies and assessed risk of bias. We resolved differences by discussion and, when necessary, sought help and suggestions from a third review author. We used a random-effects model for data analysis.

MAIN RESULTS

We included 27 randomized controlled trials (RCTs) (8244 participants analysed). Investigators reported 12 different comparisons of three different nitrates (nitroglycerin, isosorbide dinitrate and nicorandil) versus no treatment, placebo or other pharmacological interventions. All participants were older than 15 years of age. More than half of the trials used general anaesthesia. Surgical procedures in most trials were at low to moderate risk for perioperative cardiac complications. Only two comparisons including three studies reported the primary outcome - all-cause mortality up to 30 days post operation. Researchers reported other morbidity outcomes and adverse events in a variable and heterogeneous way, resulting in limited available data for inclusion in the meta-analysis. We determined that the overall methodological quality of included studies was fair to low, in accordance with risk of bias in most domains.In summary, we found no difference in the primary outcome - all-cause mortality up to 30 days post operation - when nitroglycerin was compared with no treatment (one study, 60 participants, 0/30 vs 1/30; (risk ratio (RR) 0.33, 95% confidence interval (CI) 0.01 to 7.87, very low-quality evidence based on GRADE criteria) or with placebo (two studies, 89 participants, 1/45 vs 0/44; RR 2.81, 95% CI 0.12 to 63.83, very low-quality evidence). Regarding our secondary outcomes, we noted no statistically significant differences in angina pectoris, acute myocardial infarction, acute heart failure, cardiac arrhythmia or cardiac arrest in any comparisons. In comparisons versus nitroglycerin, although more events of cardiac ischaemia were observed in participants receiving no treatment or placebo, we found no statistically significant differences in any comparisons, except the comparison of nicorandil versus placebo. One study revealed a potential dose-dependent protective effect of nicorandil for cardiac ischaemia.Adverse events were reported in a heterogeneous way among the comparisons. In general, more participants treated with nitrates had hypotension, tachycardia and headache, but investigators reported no statistically significant differences between groups in any comparisons.

AUTHORS' CONCLUSIONS

This systematic review suggests that nitroglycerin or isosorbide dinitrate is not associated with improvement in mortality and cardiac complications among patients undergoing non-cardiac surgery. Limited evidence suggests that nicorandil may reduce the risk of cardiac ischaemia in participants undergoing non-cardiac surgery. Additional studies are needed to consolidate the evidence.However, the data included in many of the analyses in this review are sparse - that is, adequate data are few - resulting in very low power to detect differences between nitrates and comparators. Thus, a more objective conclusion would state that available evidence is insufficient to show whether nitrates are associated with improvement in mortality and cardiac complications among patients undergoing non-cardiac surgery.Over the past decade, no high-quality studies have focused on association of cardiac mortality and morbidity with use of nitrates during non-cardiac surgery. This review underlines the need for well-designed trials in this field.

Technology-Enabled Remote Monitoring and Self-Management - Vision for Patient Empowerment Following Cardiac and Vascular Surgery: User Testing and Randomized Controlled Trial Protocol

Background

Tens of thousands of cardiac and vascular surgeries (CaVS) are performed on seniors in Canada and the United Kingdom each year to improve survival, relieve disease symptoms, and improve health-related quality of life (HRQL). However, chronic postsurgical pain (CPSP), undetected or delayed detection of hemodynamic compromise, complications, and related poor functional status are major problems for substantial numbers of patients during the recovery process. To tackle this problem, we aim to refine and test the effectiveness of an eHealth-enabled service delivery intervention, TecHnology-Enabled remote monitoring and Self-MAnagemenT—VIsion for patient EmpoWerment following Cardiac and VasculaR surgery (THE SMArTVIEW, CoVeRed), which combines remote monitoring, education, and self-management training to optimize recovery outcomes and experience of seniors undergoing CaVS in Canada and the United Kingdom.

Objective

Our objectives are to (1) refine SMArTVIEW via high-fidelity user testing and (2) examine the effectiveness of SMArTVIEW via a randomized controlled trial (RCT).

Methods

CaVS patients and clinicians will engage in two cycles of focus groups and usability testing at each site; feedback will be elicited about expectations and experience of SMArTVIEW, in context. The data will be used to refine the SMArTVIEW eHealth delivery program. Upon transfer to the surgical ward (ie, post-intensive care unit [ICU]), 256 CaVS patients will be reassessed postoperatively and randomly allocated via an interactive Web randomization system to the intervention group or usual care. The SMArTVIEW intervention will run from surgical ward day 2 until 8 weeks following surgery. Outcome assessments will occur on postoperative day 30; at week 8; and at 3, 6, 9, and 12 months. The primary outcome is worst postop pain intensity upon movement in the previous 24 hours (Brief Pain Inventory-Short Form), averaged across the previous 14 days. Secondary outcomes include a composite of postoperative complications related to hemodynamic compromise—death, myocardial infarction, and nonfatal stroke— all-cause mortality and surgical site infections, functional status (Medical Outcomes Study Short Form-12), depressive symptoms (Geriatric Depression Scale), health service utilization-related costs (health service utilization data from the Institute for Clinical Evaluative Sciences data repository), and patient-level cost of recovery (Ambulatory Home Care Record). A linear mixed model will be used to assess the effects of the intervention on the primary outcome, with an a priori contrast of weekly average worst pain intensity upon movement to evaluate the primary endpoint of pain at 8 weeks postoperation. We will also examine the incremental cost of the intervention compared to usual care using a regression model to estimate the difference in expected health care costs between groups.

Results

Study start-up is underway and usability testing is scheduled to begin in the fall of 2016.

Conclusions

Given our experience, dedicated industry partners, and related RCT infrastructure, we are confident we can make a lasting contribution to improving the care of seniors who undergo CaVS.