Associations Of Preoperative STOP-Bang Questionnaire Scores With Adverse Cardiovascular Events In Patients Undergoing Noncardiac Surgery:a Prospective Cohort Study

BACKGROUNDObesity is one of the major risk factors for obstructive sleep apnea(OSA).With the increase in the number of obese people worldwide,the incidence of sleep apnea is increasing.In the past few years,aged 30-69 years,23.6%have obstructive sleep apnea and 8.8%have mild to severe obstructive sleep apnea in China.In the surgical ward,the prevalence of OSA is 10%to 20%in patients undergoing elective surgery,and as high as 70%in fat-reducing surgery.However,among these patients,the proportion of undiagnosed moderate and severe OSA patients is as high as 50%to 95%.Numerous studies have shown that OSA is associated with a variety of adverse outcomes,including cardiovascular events and metabolic disorders,such as myocardial infarction,stroke,atrial fibrillation,and insulin resistance.Many studies have shown that patients with OSA have a higher incidence of postoperative complications,including higher intubation rates,hypoxemia,arrhythmias,myocardial injury and delirium.At present,the diagnosis of OSA is based on the polysomnography(PSG)of the sleep experimental center,but this examination is time-consuming and laborious,so it limits its wide application before operation.The STOP-Bang questionnaire is a simple scale commonly used in clinical screening for OSA.It has high sensitivity and its ability to predict severe OSA(AHI≥5)is up to 83.6%.Some studies have reported the relationship between the risk of OSA assessed by STOP-Bang questionnaire and postoperative complications,but most of these postoperative complications are observed by combining cardiac complications and pulmonary complications into one outcome indicator.Besides,not only the definition of cardiovascular complications is vague but also few types of cardiovascular diseases is covered.Therefore,we designed a single-center prospective cohort study to explore the association between STOP-Bang scores and postoperative adverse cardiovascular events,and whether the incidence of postoperative cardiovascular events was higher in high-risk OSA patients assessed according to STOP-Bang questionnaire than in lowrisk OSA patients.METHODS:Study designWe evaluated the association of preoperative STOP-Bang scores with postoperative adverse cardiovascular events in adult patients undergoing elective major non-cardiac surgery.Our study is a sub-study of the PREVENGE study.PREVENGE is a prospective cohort study designed to predict vascular events,other complications and mortality by preoperative high-sensitivity cardiac troponin concentration in adult patients undergoing major noncardiac surgery.This prospective cohort study was registered on chictr.org.cn(number:ChiCTR1900023 779;date of registration:June 11,2019).Approval was gained from the Medical Ethics Committee of Nanfang Hospital,Southern Medical University,and written informed consent was obtained from all patients before enrollment.The trial was conducted between July 1,2019,and June 1,2020 in the Department of Anesthesiology,Nanfang Hospital,Southern Medical University.This manuscript adheres to the Strengthening the Reporting of Observational Studies in Epidemiology(STROBE)guidelines.Patients:The inclusion criteria are all adult(age≥45 years)undergoing elective major noncardiac surgery.Patients are eligible for the study if they had 1 risk factors for postoperative cardiovascular events(ie,coronary artery disease,heart failure,stroke or transient ischemic attack,preoperative plasma NT-proBNP>300pg/ml or hs-TNT>14 ng/L)or 2 or 2 more risk factors for postoperative cardiovascular events(diabetes or hypertension requiring treatment,chronic kidney diseases with preoperative plasma creatinine concentration>132 μmol/L).Patients with American Society of Anesthesiologists(AS A)Physical Status grade 5 or refusing to join this study or can’t communicate with researcher are excluded.ProtocolFrom July 1,2019 to June 1,2020,we conducted a prospective cohort study of consecutive adult patients undergoing elective major noncardiac surgery at the Southern Medical University Nanfang hospital.A trained nurse is responsible for using electronic medical records to screen the list of all patients who meet the inclusion criteria for the second day of surgery.Other research members interview all included patients in ward to captured their detailed preoperative baseline characteristics and risk factors for postoperative cardiovascular complications.Then researchers also assess patients risk for OSA using the STOP-Bang questionnaire and the neck circumference of each patients will be measured by a measuring tape.All patients provided written informed consent.Patients,surgeon,anesthesiologist,and research members who collected the outcome data were blinded to the results of STOP-Bang questionnaire score.All eligible patients’ data will be uploaded to the online e-CRF.After surgery,venous blood samples(for measuring plasma cardiac troponin concentrations)were collected at the first 2 days and the seventh after surgery.Myocardial injury was defined as a postoperative hs-TnT concentration exceeding 20ng/L and>5ng/L than preoperative hs-TnT concentration.Additional echocardiograms and electrocardiograms were performed,if clinically indicated,to ascertain the diagnosis of cardiac complications.All patients were followed up regularly up to 30 days after surgery.Patients discharged home were contacted by telephone.Then we will evaluate the major cardiovascular adverse events and all-cause death 30 days after operation.OutcomesThe primary exposure,STOP-Bang risk stratum,is made up 8 question and low risk(scores range from 0-2),moderate risk(scores from 3-4),and high risk(scores≥5,or STOP scores≥2 with any of male sex or BMI>35 kg m’2).The primary outcome was major adverse cardiac events(a composite of myocardial injury/infarction,heart failure,stroke,pulmonary embolism,cardiac arrest,and cardiovascular death)within 30 days of surgery.The secondary outcomes were 30-day postoperative mortality,unplanned secondary intubation,and ICU transfer rate.Statistical analysisSince our study is a pure observational study,no formal sample-size calculation was performed.The number of patients enrolled is over 45 years old and is expected to undergo major non-cardiac surgery from July 2019 to June 2020.Continuous variables were described using means,medians and inter-quartile ranges,while categorical variables were described using proportions.Univariate statistics were performed to compare patient characteristics(age,sex,BMI,neck circumference,comorbidities),the ASA classification across STOP-Bang risk strata.Continuous variables were compared using variance and categorical variables were compared using χ2 test.The median values of non-normally distribute continuous variables were compared using the Kruskal-wails H test.Univariate analyses were conducted to evaluate the associations of STOP-Bang risk strata with postoperative cardiac complications and 30-day mortality.The unadjusted analyses of the associations of STOP-Bang with outcomes were conducted using logistic regression models and the adjusted associations of STOP-Bang with post-operative outcomes were examined using multivariable regression analyses.The following predictors were selected a priori for inclusion into the multivariable models:STOP-Bang risk stratum,age,sex,and patient comorbidities.The included comorbidities were age,smoking status,COPD,coronary artery disease,diabetes mellitus,heart failure,cerebrovascular disease,chronic kidney disease.A twotailed P-value<0.05 was used to define statistical significance.RESULTS:A total of 1508 patients were included in our study,172 were excluded,and finally 1242 patients were included for analysis.The main outcome occurred in 190/1242 after operation,including 19.0%(43/226)in high-risk group,15.7%(66/421)in mediumrisk group and 15.7%(66/421)in low-risk group.After multivariate analysis,there was no correlation between STOP-Bang risk rating and major adverse cardiovascular outcome.High-risk group had no increased the risk of postoperative adverse cardiovascular outcomes(adjusted odds ratio:1.10;95%confidence interval:0.66-1.84,P=0.713).Secondary outcomes showed that compared with low-risk patients,high risk patients were re-intubation(2.2%vs 1.2%,aOR1.50,95%CI 0.33-6.90 vs 0.605);postoperative ICU transferrate(11.1%vs 7.2%,OR1.36,95%CI 0.65-2.81,PSA 0.413)and 30-day postoperative mortality(1.3%vs 1.0%CI 1.93,95%low-risk patients 0.2713.74 CI 0.512).We still hadn’t observed statistical differences in these outcome variables.CONCLUSIONS:Our study did not find any correlation between STOP-Bang scores and postoperative cardiovascular complications,and STOP-Bang scores≥3 did not increase the incidence of cardiovascular complications in postoperative 30 days.Compared with low-risk patients(STOP-Bang score<3),the incidence of postoperative cardiovascular complications has not increased not only in medium-risk patients(STOP-Bang score 3-4),but also in high-risk patients(STOP-Bang score 5-8).AimAnalyze and explore the association between preoperative STOP-Bang questionnaire score and adverse cardiovascular events after non-cardiac surgery.METHODS:Electronic databases were used to search PubMed,EMBASE,and Web of Science for cohort studies on the association between preoperative STOP-Bang questionnaire scores and non-cardiac surgery postoperative cardiovascular adverse events.The search time limit is from the establishment of the database to 2020.1.31.Two researchers independently screened the literature and extracted data.The NewcastleOttawa Scale(NOS)was used to evaluate the research quality of the included studies,and the Review Manager 5.3 software was used for statistical analysis.Outcomes:A total of 5 cohort studies were included,involving a total of 32115 cases.The results of the meta-analysis showed that the high-risk OSA assessed by the STOP-Bang questionnaire was an independent risk factor for postoperative cardiovascular events(OR 1.31,95%confidence interval(CI)1.01-1.69,P<0.001).CONCLUSIONS:The preoperative STOP-Bang questionnaire score is associated with adverse cardiovascular events after non-cardiac surgery.