The association between C-reactive protein to albumin ratio and 6-month neurological outcome in patients with in-hospital cardiac arrest

The global incidence rates of in-hospital cardiac arrest(IHCA)range from1.2 to 9.0 per1,000 hospitalized patients,as per the National Cardiac Arrest Database.[1] While IHCAs tend to exhibit superior 30-day survival rates relative to out-of-hospital cardiac arrests (OHCA) due to situational advantages,such as immediate access to medical personnel and treatments.

Association of cardiometabolic multimorbidity with all-cause and cardiovascular disease mortality among Chinese hypertensive patients

BACKGROUND Hypertension usually clusters with multiple comorbidities.However,the association between cardiometabolic multimorbidity(CMM)and mortality in hypertensive patients is unclear.This study aimed to investigate the association between CMM and all-cause and cardiovascular disease(CVD)mortality in Chinese patients with hypertension.METHODS The data used in this study were from the China National Survey for Determinants of Detection and Treatment Status of Hypertensive Patients with Multiple Risk Factors(CONSIDER),which comprised 5006 participants aged 19–91 years.CMM was defined as the presence of one or more of the following morbidities:diabetes mellitus,dyslipidemia,chronic kidney disease,coronary heart disease,and stroke.Cox proportional hazard models were used to calculate the hazard ratios(HR)with 95%CI to determine the association between the number of CMMs and both all-cause and CVD mortality.RESULTS Among 5006 participants[mean age:58.6±10.4 years,50%women(2509 participants)],76.4%of participants had at least one comorbidity.The mortality rate was 4.57,4.76,8.48,and 16.04 deaths per 1000 person-years in hypertensive patients without any comorbidity and with one,two,and three or more morbidities,respectively.In the fully adjusted model,hypertensive participants with two cardiometabolic diseases(HR=1.52,95%CI:1.09–2.13)and those with three or more cardiometabolic diseases(HR=2.44,95%CI:1.71–3.48)had a significantly elevated risk of all-cause mortality.The findings were similar for CVD mortality but with a greater increase in risk magnitude.CONCLUSIONS In this study,three-fourths of hypertensive patients had CMM.Clustering with two or more comorbidities was associated with a significant increase in the risk of all-cause and cardiovascular mortality among hypertensive patients,suggesting more intensive treatment and control in this high-risk patient group.

Refining safety considerations for intradialytic blood flow restriction exercise. Commentary on “Concerns on the application of blood-flow restriction resistance exercise and thrombosis risk in hemodialysis patients”

I read with great interest the article“Concerns on the application of blood flow restriction resistance exercise and thrombosis risk in hemodialysis patients”by Correa et al.1 The study presents complementary data from a previous randomized controlled trial,2 exploring the application of intradialytic blood flow restriction exercise for hemodialysis patients.

Sleep quality in middle-aged and elderly hemodialysis patients:Impact of a structured nursing intervention program

BACKGROUND Poor sleep quality is common among hemodialysis patients and can significantly impact their well-being.This study aimed to evaluate the effectiveness of a structured nursing intervention program in improving sleep quality in middleaged and elderly hemodialysis patients.AIM To evaluate the impact of nursing intervention on sleep quality in hemodialysis patients.METHODS This cross-sectional study was conducted in a tertiary hospital,the First Affiliated Hospital of Nanchang University,in 2023.This study included 105 middle-aged and elderly hemodialysis patients aged≥45 years who underwent maintenance hemodialysis for at least 3 mo,utilizing the Pittsburgh Sleep Quality Index(PSQI)to identify poor sleepers.Those identified underwent a 12-wk nursing intervention program focusing on education,relaxation techniques,and counseling.Post-intervention,sleep quality was reassessed using the PSQI.RESULTS The study found that 68.6%of hemodialysis patients were poor sleepers.Following the 12-wk nursing intervention program,there was a significant decrease in the mean global PSQI score from 8.9±3.2 to 5.1±2.7(P<0.001),indicating improved sleep quality.This demonstrated the effectiveness of the structured nursing intervention in enhancing sleep quality for middle-aged and elderly hemodialysis patients.CONCLUSION The structured nursing intervention program focusing on sleep hygiene education,relaxation techniques,and counseling effectively improved sleep quality among middle-aged and elderly hemodialysis patients.The significant decrease in the mean global PSQI score post-intervention indicates the positive impact of tailored nursing interventions in addressing poor sleep quality in this patient population.These findings emphasize the importance of implementing targeted nursing interventions to enhance the quality of life for hemodialysis patients by addressing the prevalent issue of poor sleep quality.

Effect of remimazolam vs. propofol on hemodynamics during general anesthesia induction in elderly patients: Single-center, randomized controlled trial

The current study aimed to compare the effects between remimazolam and propofol on hemodynamic stability during the induction of general anesthesia in elderly patients.We used propofol at a rate of 60 mg/(kg·h)in the propofol group(group P)or remimazolam at a rate of 6 mg/(kg·h)in the remimazolam group(group R)for the induction.A processed electroencephalogram was used to determine whether the induction was successful and when to stop the infusion of the study drug.We measured when patients entered the operating room(T_(0)),when the induction was successful(T_(1)),and when before(T_(2))and 5 min after successful endotracheal intubation(T_(3)).We found that mean arterial pressure(MAP)was lower at T_(1–3),compared with T_(0) in both groups,but higher at T_(2) in the group R,whileΔMAP_(T0–T2) andΔMAP_(max) were smaller in the group R(ΔMAP_(T0–T2):the difference between MAP at time point T_(0) and T_(2),ΔMAP_(max):the difference between MAP at time point T_(0) and the lowest value from T_(0) to T_(3)).Cardiac index and stroke volume index did not differ between groups,whereas systemic vascular resistance index was higher at T_(1–3) in the group R.These findings show that remimazolam,compared with propofol,better maintains hemodynamic stability during the induction,which may be attributed to its ability to better maintain systemic vascular resistance levels.

Hemoperfusion and continuous veno-venous hemodiafiltration for eliminating chlorfenapyr in poisoning patients

Chlorfenapyr is a liposoluble insecticide belonging to the pyrrole family.Chlorfenapyr is activated when the N-ethoxymethyl side chain breaks,forming a toxic metabolite,which uncouples oxidative phosphorylation in the mitochondria,inhibits the production of adenosine triphosphate (ATP),and leads to the death of cells and targe organisms.[1] Symptoms of chlorfenapyr poisoning in patients are mild and atypical in the early stage,especially in patients receiving low dose exposure;however,such cases are rare and may be ignored by physicians,often leading to delayed treatment.[2,3].

Optimal timing of invasive intervention for high-risk non-ST-segment-elevation myocardial infarction patients

OBJECTIVE To compare the immediate,early,and delayed percutaneous coronary intervention(PCI)strategies in non-ST-segment-elevation myocardial infarction(NSTEMI)patients with high-risk.METHODS Medical records of patients treated at the Daping Hospital,Third Military Medical University,Chongqing,China between 2011 and 2021 were retrospectively reviewed.Only patients with complete available information were included.All patients assigned into three groups based on the timing of PCI including immediate(<2 h),early(2–24 h)and delayed(≥24 h)intervention.Multivariable Cox hazards regression and simpler nonlinear models were performed.RESULTS A total of 657 patients were included in the study.The median follow-up length was 3.29(interquartile range:1.45–4.85)years.Early PCI strategy improved the major adverse cardiac event(MACE)outcome compared to the immediate or delayed PCI strategy.Early PCI,diabetes mellitus,and left main or/and left anterior descending or/and left circumflex stenosis or/and right coronary artery≥99%were predictors for MACE outcome.The optimal timing range for PCI to reduce MACE risk is 3–14 h post-admission.For high-risk NSTEMI patients,early PCI reduced primary clinical outcomes compared to immediate or delayed PCI,and the optimal timing range was 3–14 h post-admission.Delayed PCI was superior for NSTEMI with chronic kidney injury.CONCLUSIONS Delayed invasive strategy was helpful to reduce the incidence of MACE for high-risk NSTEMI with chronic kidney injury.An immediate PCI strategy might increase the rate of MACE.

Bridging fulminant myocarditis patients to recovery or advanced therapies with veno-arterial extracorporeal membrane oxygenation:a single-center retrospective study

Fulminant myocarditis(FM)is a severe inflammatory cardiac disease,typically triggered by viral pathogens or autoimmune disorders.[1,2]Early symptoms of the disease can be mild and nonspecific,but in certain cases,patients may experience sudden and severe heart failure,arrhythmias,refractory cardiogenic shock,or even death.

Risk factors for early death in severe non-brain- injured trauma patients

Severe trauma is one of the main causes of premature death,posing a significant challenge to public health systems.[1]At present,there is a lack of universally accepted guidelines for rapid detection of life-threatening severe trauma,[2]and the accuracy of existing prognostic models in predicting early death is limited.[3,4]Severe non-brain-injured trauma(SNT)patients account for approximately 70%of all trauma-related deaths.Moreover,there is a lack of studies on early death in SNT patients.[5]This study aims to identify risk factors associated with early death(≤72 h post-admission)in SNT patients.

Timing of hepatectomy following the Omicron variant infection for vaccinated-patients:A retrospective cohort study

Many previous studies suggested that severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) infection elevated the risk of morbidity and 90-day mortality after operation, especially pulmonary complications [1–7]. Uncertainty about perioperative safety puts off the progress of elective surgery [8]. The Omicron variant has recently become the dominant variant causing prevalence in several countries [9]. Although a high rate of patients with Omicron presented asymptomatic status [10], it is still unclear whether Omicron infection would raise the risk of postoperative complications.

Predicting cardiovascular events in out-of-hospital patients presenting with atypical chest pain and complete left bundle branch block: role of CTA and echocardiographic Global Longitudinal Strain

Background Out-of-hospital patients presenting with atypical chest pain and complete left bundle branch block(LBBB)have to be stratified for the presence of coronary artery disease and the risk of developing heart failure(HF).We investigated the pro-gnostic role of coronary CT-angiography(CTA)and echocardiographic global longitudinal strain(GLS)in those patients in a mid-term follow-up.Methods Out-of-hospital patients with LBBB underwent echocardiography and a 64-slice CT angiography were evaluated ret-rospectively.Development of HF or a cardiovascular death were the events scheduled.Results Seventy-eight patients(32 female;mean age:66.0±10.4 years were enrolled.During a follow-up of 33 months(IQR:17-77),one patient(1.5%)experienced a cardiovascular death,14 patients(17.9%)required urgent outpatient visits due to acute de-compensated HF(12 hospitalizations).Echocardiography showed a slightly reduced left ventricular ejection fraction(LVEF)(50.0%±9.8%)and GLS within the normal range(-16.2%±4.1%).CTA analysis showed coronary stenosis>50%in 28 patients(35.9%).A high Agatston score(>100)was observed in 29.5%.Notably,25 patients(32.1%)were diagnosed with left main coron-ary artery disease and 15 patients(16.7%)underwent revascularization during the follow up.Significant associations were ob-served between events and LVEF(P=0.001),diastolic dysfunction grade≥2(P=0.02),GLS(P<0.001),multiple coronary stenos-is(P=0.04)and Agatston score(P=0.05).Multivariate analysis confirmed the relationships with LVEF(R^(2)=0.89,P<0.001),dia-stolic dysfunction(R^(2)=3.30,P=0.04),GLS(R^(2)=1.43,P<0.001),and Agatston score(R^(2)=1.01,P=0.05).Conclusions In patients with complete LBBB,CTA and GLS identified those at a high risk of development HF.

Association of prealbumin with short-term and long-term outcomes in patients with acute ST-segment elevation myocardial infarction

BACKGROUND Prealbumin is considered to be a useful indicator of nutritional status. Furthermore, it has been found to be associated with severities and prognosis of a range of diseases. However, limited data on the association of baseline prealbumin level with outcomes of patients with acute ST-segment elevation myocardial infarction(STEMI) are available.METHODS We analyzed 2313 patients admitted for acute STEMI between October 2013 and December 2020. In-hospital outcomes and mortality during the 49 months(interquartile range: 26–73 months) follow-up period were compared between patients with the low prealbumin level(< 170 mg/L) and those with the high prealbumin level(≥ 170 mg/L).RESULTS A total of 114 patients(4.9%) died during hospitalization. After propensity score matching, patients with the low prealbumin level than those with the high prealbumin level experienced higher incidences of heart failure with Killip class Ⅲ(9.9%vs. 4.4%, P = 0.034), cardiovascular death(8.4% vs. 3.4%, P = 0.035) and the composite of major adverse cardiovascular events(19.2%vs. 10.3%, P = 0.012). Multivariate logistic regression analysis identified that the low prealbumin level(< 170 mg/L) was an independent predictor of in-hospital major adverse cardiovascular events(odds ratio = 1.918, 95% CI: 1.250–2.942, P = 0.003). The cutoff value of prealbumin level for predicting in-hospital death was 170 mg/L(area under the curve = 0.703, 95% CI: 0.651–0.754, P< 0.001;sensitivity = 0.544, specificity = 0.794). However, after multivariate adjustment of possible confounders, baseline prealbumin level(170 mg/L) was no longer independently associated with 49-month cardiovascular death. After propensity score matching, Kaplan-Meier survival curves revealed consistent results.CONCLUSIONS Decreased prealbumin level closely related to unfavorable short-term outcomes. However, after multivariate adjustment and controlling for baseline differences, baseline prealbumin level was not independently associated with an increased risk of long-term cardiovascular mortality in STEMI patients.

Predictive value of neutrophil-to-lymphocyte ratio in coronary chronic total occlusion patients

BACKGROUND The neutrophil to lymphocyte ratio(NLR)has been reported as a novel predictor for atherosclerosis and car-diovascular outcomes.This study aimed to determine the effects of NLR on long-term clinical outcomes of chronic total occlusion(CTO)patients.METHODS A total of 670 patients with CTO who met the inclusion criteria were included at the end of the follow-up period.Patients were divided into tertiles according to their baseline NLR levels at admission:low(n=223),intermediate(n=223),and high(n=224).The incidence of major adverse cardiac events(MACEs)during the follow-up period,including all-cause death,nonfatal myocardial infarction(MI),or ischemia-driven revascularization,were compared among the three groups.RESULTS Major adverse cardiac events were observed in 27 patients(12.1%)in the low tertile,40(17.9%)in the intermediate tertile,and 61(27.2%)in the high NLR tertile(P<0.001).Kaplan-Meier analysis demonstrated a significantly higher incidence of MACE,ischemia-driven coronary revascularization,non-fatal MI,and mortality in patients within the high tertile than those in the low and intermediate groups(all P<0.001).Multivariable COX regression analysis showed that the high tertile of baseline NLR level showed a strong association with the risk of MACE(hazard ratio[HR]=2.21;95%confidence interval[CI]:1.21-4.03;P=0.009),ischemia-driven coronary revascularization(HR=3.19;95%CI:1.56-6.52;P=0.001),MI(HR=2.61;95%CI:1.35-5.03;P=0.043)and mortality(HR=3.78;95%CI:1.65-8.77;P=0.001).CONCLUSION Our findings suggest that NLR is an inexpensive and readily available biomarker that can independently pre-dict cardiovascular risk in patients with CTO.

The effect of fasting plasma glucose on in-hospital mortality after acute myocardial infarction in patients with and without diabetes:findings from a prospective,nationwide,and multicenter registry

OBJECTIVES To evaluate the predictive value of fasting plasma glucose(FPG)for in-hospital mortality in patients with acute myocardial infarction(AMI)with different glucose metabolism status.METHODS We selected 5,308 participants with AMI from the prospective,nationwide,multicenter CAMI registry,of which 2,081 were diabetic and 3,227 were nondiabetic.Patients were divided into high FPG and low FPG groups according to the optim-al cutoff values of FPG to predict in-hospital mortality for diabetic and nondiabetic cohorts,respectively.The primary endpoint was in-hospital mortality.RESULTS Overall,94 diabetic patients(4.5%)and 131 nondiabetic patients(4.1%)died during hospitalization,and the optimal FPG thresholds for predicting in-hospital death of the two cohorts were 13.2 mmol/L and 6.4 mmol/L,respectively.Compared with individuals who had low FPG,those with high FPG were significantly associated with higher in-hospital mortality in diabet-ic cohort(10.1%vs.2.8%;odds ratio[OR]=3.862,95%confidence interval[CI]:2.542-5.869)and nondiabetic cohort(7.4%vs.1.7%;HR=4.542,95%CI:3.041-6.782).After adjusting the potential confounders,this significant association was not changed.Further-more,FPG as a continuous variable was positively associated with in-hospital mortality in single-variable and multivariable models regardless of diabetic status.Adding FPG to the original model showed a significant improvement in C-statistic and net reclassification in diabetic and nondiabetic cohorts.CONCLUSIONS This large-scale registry indicated that there is a strong positive association between FPG and in-hospital mor-tality in AMI patients with and without diabetes.FPG might be useful to stratify patients with AMI.

Heterogeneous body compositions and all-cause mortality in acute coronary syndrome patients:a ten-year retrospective cohort study

BACKGROUND The association of different body components,including lean mass and body fat,with the risk of death in acute coronary syndrome(ACS)patients are unclear.METHODS We enrolled adults diagnosed with ACS at our center between January 2011 and December 2012 and obtained fol-low-up outcomes via telephone questionnaires.We used restricted cubic splines(RCS)with the Cox proportional hazards model to analyze the associations between body mass index(BMI),predicted lean mass index(LMI),predicted body fat percentage(BF),and the value of LMI/BF with 10-year mortality.We also examined the secondary outcome of death during hospitalization.RESULTS During the maximum 10-year follow-up of 1398 patients,331 deaths(23.6%)occurred,and a U-shaped relationship was found between BMI and death risk(P_(nonlinearity)=0.03).After adjusting for age and history of diabetes,the overweight group(24≤BMI<28 kg/m^(2))had the lowest mortality(HR=0.53,95%CI:0.29-0.99).Predicted LMI and LMI/BF had an inverse linear relationship with a 10-year death risk(P_(nonlinearity)=0.24 and P_(nonlinearity)=0.38,respectively),while an increase in BF was associ-ated with increased mortality(P_(nonlinearity)=0.64).During hospitalization,31 deaths(2.2%)were recorded,and the associations of the indicators with in-hospital mortality were consistent with the long-term outcome analyses.CONCLUSION Our study provides new insight into the“obesity paradox”in ACS patients,highlighting the importance of considering body composition heterogeneity.Predicted LMI and BF may serve as useful tools for assessing nutritional status and predicting the prognosis of ACS,based on their linear associations with all-cause mortality.

Development and validation of a model integrating clinical and coronary lesion-based functional assessment for longterm risk prediction in PCI patients

OBJECTIVES To establish a scoring system combining the ACEF score and the quantitative blood flow ratio(QFR) to improve the long-term risk prediction of patients undergoing percutaneous coronary intervention(PCI).METHODS In this population-based cohort study, a total of 46 features, including patient clinical and coronary lesion characteristics, were assessed for analysis through machine learning models. The ACEF-QFR scoring system was developed using 1263consecutive cases of CAD patients after PCI in PANDA Ⅲ trial database. The newly developed score was then validated on the other remaining 542 patients in the cohort.RESULTS In both the Random Forest Model and the Deep Surv Model, age, renal function(creatinine), cardiac function(LVEF)and post-PCI coronary physiological index(QFR) were identified and confirmed to be significant predictive factors for 2-year adverse cardiac events. The ACEF-QFR score was constructed based on the developmental dataset and computed as age(years)/EF(%) + 1(if creatinine ≥ 2.0 mg/d L) + 1(if post-PCI QFR ≤ 0.92). The performance of the ACEF-QFR scoring system was preliminarily evaluated in the developmental dataset, and then further explored in the validation dataset. The ACEF-QFR score showed superior discrimination(C-statistic = 0.651;95% CI: 0.611-0.691, P < 0.05 versus post-PCI physiological index and other commonly used risk scores) and excellent calibration(Hosmer–Lemeshow χ^(2)= 7.070;P = 0.529) for predicting 2-year patient-oriented composite endpoint(POCE). The good prognostic value of the ACEF-QFR score was further validated by multivariable Cox regression and Kaplan–Meier analysis(adjusted HR = 1.89;95% CI: 1.18–3.04;log-rank P < 0.01) after stratified the patients into high-risk group and low-risk group.CONCLUSIONS An improved scoring system combining clinical and coronary lesion-based functional variables(ACEF-QFR)was developed, and its ability for prognostic prediction in patients with PCI was further validated to be significantly better than the post-PCI physiological index and other commonly used risk scores.

The impact of being in the COVID-19 pandemic on in-hospital mortality of non-infected patients aged 80 years and older with ST-elevation myocardial ınfarction

The COVID-19 outbreak in late 2019 was declared a pandemic by the World Health Organization(WHO)on March 12,2020.[1]As of the latest WHO data,COVID-19 has caused over 770 million cases and nearly 7 million deaths worldwide.[2]Hospitalizations due to COVID-19 are correlated with advanced age.[3,4]According to re-ports,individuals over the age of 65 account for 80%of COVID-19-related deaths.[3,4]This is primar-ily due to the increased burden of comorbidity with age.

Potential role of peripheral blood mononuclear cell' s mitochondrial respiratory dysfunction in heart failure severity prediction in patients with cardioverter-defibrillator implantation indications

Background It has been reported that the mitochondrial respiratory dysfunction (MRD) is important mechanisms affecting the heart failure (HF) pathogenesis.We sought to evaluate the potential role of MRD of peripheral blood mononuclear cells (PBMC) in HF severity prediction in patients with cardioverter-defibrillator implantation indications.Methods In this single-center study patients with HF of New York Heart Association (NYHA) Ⅰ-Ⅲ functional class (FC) and cardioverter-defibrillator implantation indications underwent transthoracic echocardiography (TTE) and MRD assessment using PB-MC.Mitochondrial respiration rate (MRR) indicators (pyruvate+malate+adenosine diphosphate;succinate+adenosine diphosphate;pyruvate+malate–adenosine diphosphate[V4.1];succinate–adenosine diphosphate) were calculated.Correlations between HF NYHA FC,TTE and MRR indicators were evaluated.Based on our data,we developed a risk model regarding HF severity.Results Of 53 (100.0%) HF patients,33 (62.3%) had mild exercise intolerance (1stgroup) and 20 (37.7%) had moderate-to-severe exercise intolerance (2ndgroup).Patients with mild exercise intolerance were likely to have a higher V4.1(P<0.001) values.V4.1was independently associated with moderate-to-severe exercise intolerance in univariate and multivariate logistic regression (OR=0.932,95%CI:0.891–0.975,P<0.001).Conclusions The severity of HF is associated with PBMC mitochondrial respiratory dysfunction in patients with cardioverter-defibrillator implantation indications.Our HF severity risk model including V4.1parameters is able to distinguish patients with mild and moderate-to-severe exercise intolerance.Further investigations of their predictive significance are warranted.

Exploring the Pathways of Leprosy Patients from Their Communities to a Diagnosis in the Districts of Mayuge, Yumbe and Kasese-Uganda

Background: Leprosy is known to cause disability that leads to severe outcomes like stigma, discrimination, mental health problems and participation restriction. Furthermore, in cases of infectious leprosy, longer delays increase the risk for the spread of the disease. Despite being preventable and curable, a significant proportion of new leprosy patients (39%) in 2019 had grade 2 (Described as Visible disability) at the time of diagnosis signifying late presentation. The aim of this study was to describe patient journeys from first symptoms suggestive of leprosy to a diagnosis and individual and community level factors associated with health seeking behavior of leprosy patients. Methods: This was a cross-sectional explorative study implemented in Kasese, Mayuge and Yumbe districts .A structured questionnaire was used to collect quantitative data. Qualitative assessment included patients, family members, health workers, voluntary health teams and the district health team. Descriptive statistics were presented in terms of percentages, frequency tables, pie Charts and graphs for easy interpretation and discussion. Results: The results indicate that 53% of the respondents identified as female. The median age of the respondents being 34 years, with a range of 1 to 76 years (Mean: 44.7, Mode: 65, Standard-Deviation: 19.6, Kurtosis: 0.6). The most common first symptom noticed by respondents was skin lesions (65%) followed by deformities (18%) (P value = 0.05%) occurring mostly in the feet (P-value = 0.48). Majority (52%) of the patients had taken more than 24 months (SD 18.72 OR 2.75) for a diagnosis to be made with a maximum delay of over 60 months. The most common cause of delay in seeking health care was lack of knowledge on leprosy (P value=Conclusions: There was a delay of 2 years in seeking health care for the majority of the patients. Key barriers to early diagnosis were lack of knowledge and infrastructure. Community sensitization and strengthening capacity building are needed to achieve early diagnosis of leprosy and proper management.

Lower synaptic density and its association with cognitive dysfunction in patients with obsessive-compulsive disorder

Background Understanding synaptic alteration in obsessive-compulsive disorder(OCD)is crucial for elucidating its pathological mechanisms,but in vivo research on this topic remains limited.Aims This study aimed to identify the synaptic density indicators in OCD and explore the relationship between cognitive dysfunction and synaptic density changes in OCD.Methods This study enrolled 28 drug-naive adults with OCD aged 18-40 years and 16 healthy controls(HCs).Three-dimensional T1-weighted structural magnetic resonance imaging and 18F-SynVesT-1 positron emission tomography were conducted.Cognitive function was assessed using the Wisconsin Cart Sorting Test(WCST)in patients with OCD and HCs.Correlative analysis was performed to examine the association between synaptic density reduction and cognitive dysfunction.Results Compared with HCs,patients with OCD showed reduced synaptic density in regions of the cortico-striatothalamo-cortical circuit such as the bilateral putamen,left caudate,left parahippocampal gyrus,left insula,left parahippocampal gyrus and left middle occipital lobe(voxel p<0.001,uncorrected,with cluster level above 50 contiguous voxels).The per cent conceptual-level responses of WCST were positively associated with the synaptic density reduction in the left middle occipital gyrus(R^(2)=0.1690,p=0.030),left parahippocampal gyrus(R^(2)=0.1464,p=0.045)and left putamen(R^(2)=0.1967,p=0.018)in patients with OCD.Conclusions Adults with OCD demonstrated lower 18Flabelled difluoro analogue of 18F-SynVesT-1 compared with HCs,indicating potentially lower synaptic density.This is the first study to explore the synaptic density in patients with OCD and provides insights into potential biological targets for cognitive dysfunctions in OCD.