Morphological risk of acute type A aortic dissection in the mildly to moderately dilated aorta.

OBJECTIVES: This study aimed to analyse and determine the role of aortic length and curvature in the pathogenesis of acute type A aortic dissection (ATAAD) with ascending aortic diameters (AADs) <5 cm. METHODS: We reviewed the clinical and imaging data of patients with ATAAD (n = 201) and ascending aortic dilation (n = 83). Thoracic aortic bending index (TABI) was used to quantify aortic curvature and analyse its role in ATAAD below the diameter risk threshold. RESULTS: The AAD was <5.0 and <4.0 cm in 78% and 37% of patients with ATAAD, respectively. The median ascending aortic length (AAL) was 104.6 mm (Q1-Q3, 96.5-113.6 mm), and in 62.7% of patients, it was <11 cm. The median TABI was 14.99 mm/cm (Q1-Q3, 14.18-15.86 mm/cm). Patients with ATAAD and those with aortic dilation were matched for AAD, age, sex, height and other clinical factors. After matched, the dissection group had higher AALs (median, 102.9 mm; Q1-Q3, 96.0-112.5 mm vs median, 88.2 mm; Q1-Q3, 83.7-95.9 mm; P < 0.001) and TABI (median, 14.84 mm/cm; Q1-Q3, 14.06-15.83 mm/cm vs median, 13.55 mm/cm; Q1-Q3, 13.03-14.28 mm/cm; P < 0.001). According to the regression analysis, the area under the curve required to distinguish patients with ATAAD from those with aortic dilation was 0.831 in AAL, 0.837 in TABI and 0.907 when AAL was combined with TABI. CONCLUSIONS: The patients with ATAAD had higher AAL and TABI than those with aortic dilation. The combination of TABI and AAL might be a potential morphological marker for determining ATAAD risk below the current aortic diameter risk threshold.

Gene modules and genes associated with postoperative atrial fibrillation: weighted gene co-expression network analysis and circRNA-miRNA-mRNA regulatory network analysis.

Background: Atrial fibrillation (AF) is the most common complication in patients undergoing cardiac surgery. However, the pathogenesis of postoperative AF (POAF) is elusive, and research related to this topic is sparse. Our study aimed to identify key gene modules and genes and to conduct a circular RNA (circRNA)-microRNA (miRNA)-messenger RNA (mRNA) regulatory network analysis of POAF on the basis of bioinformatic analysis. Methods: The GSE143924 and GSE97455 data sets from the Gene Expression Omnibus (GEO) database were analyzed. Weighted gene co-expression network analysis (WGCNA) was used to identify the key gene modules and genes related to POAF. A circRNA-miRNA-mRNA regulatory network was also built according to differential expression analysis. Functional enrichment analysis was further performed according to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Results: WGCNA identified 2 key gene modules and 44 key genes that were significantly related to POAF. Functional enrichment analysis of these key genes implicated the following important biological processes (BPs): endosomal transport, protein kinase B signaling, and transcription regulation. The circRNA-miRNA-mRNA regulatory network suggested that KLF10 may take critical part in POAF. Moreover, 2 novel circRNAs, hsa_circRNA_001654 and hsa_circRNA_005899, and 2 miRNAs, hsa-miR-19b-3p and hsa-miR-30a-5p, which related with KLF10, were involved in the network. Conclusions: Our study provides foundational expression profiles following POAF based on WGCNA. The circRNA-miRNA-mRNA network offers insights into the BPs and underlying mechanisms of POAF.

A novel physics-based model for fast computation of blood flow in coronary arteries.

Blood flow and pressure calculated using the currently available methods have shown the potential to predict the progression of pathology, guide treatment strategies and help with postoperative recovery. However, the conspicuous disadvantage of these methods might be the time-consuming nature due to the simulation of virtual interventional treatment. The purpose of this study is to propose a fast novel physics-based model, called FAST, for the prediction of blood flow and pressure. More specifically, blood flow in a vessel is discretized into a number of micro-flow elements along the centerline of the artery, so that when using the equation of viscous fluid motion, the complex blood flow in the artery is simplified into a one-dimensional (1D) steady-state flow. We demonstrate that this method can compute the fractional flow reserve (FFR) derived from coronary computed tomography angiography (CCTA). 345 patients with 402 lesions are used to evaluate the feasibility of the FAST simulation through a comparison with three-dimensional (3D) computational fluid dynamics (CFD) simulation. Invasive FFR is also introduced to validate the diagnostic performance of the FAST method as a reference standard. The performance of the FAST method is comparable with the 3D CFD method. Compared with invasive FFR, the accuracy, sensitivity and specificity of FAST is 88.6%, 83.2% and 91.3%, respectively. The AUC of FFRFAST is 0.906. This demonstrates that the FAST algorithm and 3D CFD method show high consistency in predicting steady-state blood flow and pressure. Meanwhile, the FAST method also shows the potential in detecting lesion-specific ischemia.

Incidence of Acute Kidney Injury and Risk Factors of Prognosis in Patients with Acute Stanford Type A Aortic Dissection.

PURPOSE: We aimed to investigate the prognosis and impact of postoperative acute kidney injury (AKI) in acute Stanford type A aortic dissection (ATAAD) patients, and to analyze the predictors of short- and medium-term survival. METHODS: A total of 192 patients who underwent ATAAD surgery were included between May 2014 and May 2019. Perioperative data of these patients were analyzed. All of the discharged patients were followed up for 2 years. RESULTS: Postoperative AKI was identified in 43 of 192 patients (22.4%). The two-year survival rate of patients with AKI after discharge was 88.2% and that without AKI was 97.2%.The difference was statistically significant (χ2 = 5.355, log-rank P = 0.021). Cox hazards regression showed that age (hazard ratio [HR], 1.070; P = 0.002), cardiopulmonary bypass (CPB) time (HR, 1.026; P = 0.026), postoperative AKI (HR, 3.681; P = 0.003), and red blood cell transfusion (HR, 1.548; P = 0.001) were independent risk factors for the short- and medium-term total mortality of ATAAD patients. CONCLUSION: The incidence of postoperative AKI is high in ATAAD, and the mortality of patients with AKI increases significantly within 2 years. Age, CPB time, and red blood cell transfusion were also independent risk factors for short-and medium-term prognoses.

Analysis of Prognosis and Risk Factors for Postoperative Hepatic Dysfunction in Patients with Acute Type A Aortic Dissection.

BACKGROUND: To explore the prognosis and risk factors of postoperative hepatic dysfunction in patients with acute type A aortic dissection. METHODS: A total of 156 patients who underwent surgery for acute type A aortic dissection in our hospital from May 2014 to May 2018 were retrospectively enrolled. The patients were divided into 2 groups based on postoperative liver function. The postop-erative model for end-stage liver disease score was used to define hepatic dysfunction. There were 35 patients with postoperative hepatic dysfunction (group hepatic dysfunction, model for end-stage liver disease score ≥ 15) and 121 patients without postoperative hepatic dysfunction (group non-hepatic dysfunction, model for end-stage liver disease score < 15). Univariate and multiple analyses (logistic regression) were used to identify the predictive risk factors. RESULTS: In-hospital mortality rate was 8.3%. Multiple logistic analysis showed that preoperative alanine aminotransferase (P <.001), cardiopulmonary bypass time (P <.001), and red blood cell transfusion (P <.001) were independent determinants for postoperative hepatic dysfunction. The patients were followed up for 2 years, with an average follow-up of 22.9 ± 3.2 months, and the lost follow-up rate was 9.1%. The short- and medium-term mortality in hepatic dysfunction group was higher than that in non-hepatic dysfunction group (log-rank P =.009). CONCLUSIONS: The incidence of postoperative hepatic dysfunction is high in patients with acute type A aortic dissection. Preoperative alanine aminotransferase, cardiopulmonary bypass time, and red blood cell transfusion were independent risk factors for those patients. The short- and medium-term mortality in hepatic dysfunction group was higher than that in non-hepatic dysfunction group.

Prospective Study on the Postoperative Use of Levosimendan After Conventional Heart Valve Replacement.

BACKGROUND The aim of this study was to explore the effect of levosimendan in patients after heart valve replacement and its influence on postoperative recovery. MATERIAL AND METHODS This prospective study included 185 patients with valvular diseases undergoing conventional valve replacement. Patients were divided into 2 groups using a random number table before surgery. Patients in the levosimendan group were administrated levosimendan intravenous infusion immediately after entering the Intensive Care Unit (ICU). The left ventricular ejection fraction (LVEF), cardiac output, and heart failure-related index, such as B-type natriuretic peptide (BNP) level, were recorded at 1, 3, and 7 days after surgery. The dosage and administration time of dopamine and epinephrine, mechanical ventilation time, ICU length of stay, and postoperative adverse events were recorded. RESULTS Cardiac output and LVEF of patients in the levosimendan group were significantly higher than those in the control group at different time points (P<0.05), and BNP level was lower than that of the control group (P<0.0001). Dosage and administration time of dopamine and epinephrine in the levosimendan group were lower than those of the control group (P<0.0001, P<0.0001, respectively). ICU length of stay and total incidence of postoperative adverse events were lower than those of the control group (P<0.0001, P=0.002, respectively). CONCLUSIONS Levosimendan administration immediately after heart valve replacement effectively improved the heart function of patients, reduced administration of vasoactive drugs, shortened length of ICU stay, reduced incidence of postoperative adverse events, and promoted recovery of patients after surgery.

Optimization of 4D flow MRI velocity field in the aorta with divergence-free smoothing.

Divergence-free smoothing with wall treatment (DFSwt) method is proposed for processing with four-dimensional (4D) flow magnetic resonance imaging (MRI) data of blood flows to enhance the quality of flow field with physical constraints. The new method satisfies the no-slip wall boundary condition and applies wall function of velocity profile for better estimating the velocity gradient in the near-wall region, and consequently improved wall shear stress (WSS) calculation against the issue of coarse resolution of 4D flow MRI. In the first testing case, blood flow field obtained from 4D flow MRI is well smoothed by DFSwt method. A great consistency is observed between the post-processed 4D flow MRI data and the computational fluid dynamics (CFD) data in the interested velocity field. WSS has an apparent improvement due to the proposed near-wall treatment with special wall function comparing to the result from original 4D flow MRI data or the DFS-processed data with no wall function. The other five cases also show the same performance that smoothed velocity field and improved WSS estimation are achieved on 4D flow MRI data optimized by DFSwt. The improvements will benefit the study of hemodynamics regarding the determination of location or the potential possibility of lesions.

A meta-analysis of the incidence rate of postoperative acute kidney injury in patients with congenital heart disease.

BACKGROUND: Acute kidney injury (AKI) is a common complication of cardiac surgery. However, the incidence rate of AKI in patients with congenital heart disease (CHD) greatly varies between reports owing to the different definitions used for AKI. Therefore, this study was designed as a meta-analysis aimed at summarizing the incidence rate of AKI in patients with congenital heart disease (CHD) on the basis of different AKI criteria. METHODS: Studies published till April 24, 2020, on the incidence rate of AKI in patients with CHD, were retrieved from electronic databases and printed literature. To pool data from the included studies, the effect size, a combined statistics, was chosen and presented with the incidence rate and 95% confidence interval (CI). Heterogeneity was evaluated using I2 statistics and Cochran Q test. The incidence rates obtained from the subgroup analysis according to study location, type of surgery, type of cohort, age, and AKI criteria) were also evaluated to determine the correlation of AKI with these factors. Publication bias was estimated using the Egger test. RESULTS: Thirty studies, comprising 9925 patients with AKI who had CHD, were included. Overall, the pooled incidence rate of AKI in the patients with CHD was 38.4% (95% CI, 32.0-44.7%). However, the incidence rate was not significantly affected by gender, study location, type of surgery, type of cohort, and AKI criteria. Moreover, age was significantly associated with the incidence of AKI, and the incidence rate was higher in the patients aged < 1 month than in those aged 1 month to 18 years, < 18 years, and ≥ 18 years (P < 0.05). CONCLUSIONS: In this study, the estimated incidence rate of AKI in patients with CHD was 38.4% and may be influenced by age. These findings highlight the importance of further investigation of the specific causes of and effective preventive measures for AKI.

Anti-apoptosis effect of heme oxygenase-1 on lung injury after cardiopulmonary bypass.

BACKGROUND: This study aimed to investigate the anti-apoptosis effects of heme oxygenase-1 (HO-1) on lung injury (LI) after cardiopulmonary bypass (CPB) and its probable mechanisms. METHODS: One hundred and forty-four male Wistar rats were divided into 3 groups randomly: group A (control group), group B (cobalt protoporphyrin, CoPP), and group C [CoPP plus zinc protoporphyrin (ZnPP)]. Lung tissues were harvested at different time: before CPB (T0), 0 min after CPB (T1), 2 h after CPB (T2), 6 h (T3), 12 h (T4), and 24 h (T5). RESULTS: The HO-1 protein expressions in lung tissue in group B were higher than those in group A and group C in any given time, and the same as HO-1 activity (P<0.05). The expressions of Bcl-2 protein in group B at all time point after bypass were higher than those in group A and group C, and the difference was statistically significant (P<0.05). Apoptosis index (AI) in group B at any time point after bypass were lower than those in group A and group C (P<0.05). CONCLUSIONS: CoPP can significantly increase the expression of HO-1 protein in lung tissue. HO-1 is still highly expressed after CPB, so as to play an important part in anti-apoptosis, and reduce LI.

Predictive risk factors for acute kidney injury after surgery for Stanford type A acute aortic dissection / 中国胸心血管外科临床杂志

@#Objective To identify the predictors of postoperative acute kidney injury in patients undergoing surgery for Stanford type A acute aortic dissection. Methods A total of 220 patients who underwent surgery for type A acute aortic dissection in Qingdao Municipal Hospital from September 2010 to September 2017 were divided into two groups including a group A and a group B based on whether acute kidney injury occurred or not after surgery. There were 40 patients with 29 males and 11 females with the mean age of 54.6±9.2 years in the group A, 180 patients with 133 males and 47 females with the mean age of 48.5±7.9 years in the group B. Univariate and multivariate analyses (logistic regression) were used to identify the predictive risk factors. Results Overall in-hospital mortality was 5.5%. In univariate analysis, there were statistically significant differences with respect to the age, preoperative creatinine, preoperative white blood cell, the European system for cardiac operative risk evaluation (EuroSCORE), total cardiopulmonary bypass (CPB) time, deep hypothermic circulatory arrest (DHCA) time, arch replacement, red blood cell transfusion intraoperative and in 24 hours postoperatively, postoperative mechanical ventilation time, ICU stay duration, hospital stay duration and in hospital mortality. Multivariate logistic analysis showed that preoperative creatinine, preoperative white blood cell, CPB time, and red blood cell transfusion intraoperative and in 24 hours postoperatively were the independent predictors for postoperative acute kidney injury. Conclusion The incidence of acute kidney injury is high after surgery for acute Stanford type A aortic dissection. It can be predicted based on above factors, for patients with these risk factors, more perioperative care strategies are needed in order to induce the incidence of acute kidney injury.

Effects of levosimendan on patients undergoing valve replacement / 中国胸心血管外科临床杂志

@#Objective    To investigate the effect of postoperative use of levosimendan on patients with valve replacement. Method    Patients with valvular diseases who underwent valve replacement were prospectively enrolled during Jan 2014 to May 2018 in Qingdao Municipal Hospital, randomized to a levosimendan-treated group (n=93) and a control group (n=92) preoperatively. Patients in both groups underwent the same routine treatment preoperatively and postoperatively. In addition, patients in the levosimendan-treated group underwent levosimendan intravenous infusion 24 hours after entering ICU postoperatively. The clinical effect of the two groups was compared. Results    Compared to the control group, the cardiac output(CO, 5.2±1.0 L/min vs. 4.4±1.1 L/min on the seventh day after surgery) and left ventricular ejection fraction (LVEF, 55.7%±2.5% vs. 50.5%±2.2% on the seventh day after surgery) of levosimendan-treated group were increased significantly at different time points(1 day, 3 days and 7 days after surgery)(P<0.05), and the brain natriuetic peptid (BNP) level (312.5±34.6 pg/ml vs. 455.4±45.2 pg/ml on the seventh day after surgery) was less than that of the control group (P<0.05). The dosage (11.5±1.8 mg/kg vs. 20.4±2.1 mg/kg) and administration time of vasoactive agents in the levosimendan-treated group were significantly lower or shorter than those in the control group (70.4±11.2 h vs. 110.5±12.1 h, P<0.05). The ICU stay length, and the total incidence of adverse events were less than those of the control group (P<0.05). Conclusion    Postoperative use of levosimendan immediately after surgery can significantly improve the   cardiac function status of patients who underwent valve replacement, reduce the dosage of vasoactive agents, shorten the time of ICU hospitalization, reduce the incidence of adverse events and enhance the patient’s recovery after valve replacement.

Transcriptomic responses of peripheral blood cells to coronary artery disease.

Transcriptomic response of peripheral blood cells to coronary artery diseases (CAD) is a long recognized phenomenon. Currently, accumulating evidence indicates that such response having significant clinical utility in CAD-associated events determination. In this review, we summarized the existing data of transcriptomic biomarkers at mRNA, microRNA, long non-coding RNA, and circular RNA for the diagnosis, progression and outcome prediction and treatment response of CAD. Furthermore, we also discussed the functional significance on the gene expression patterns caused by CAD, and emphasized the importance of inflammatory pathways in CAD tissues-blood cells interaction. Based on the current knowledge, we proposed a perspective on the future strategies to further improve the robustness and reproducibility of transcriptomic biomarkers in the personalized medicine of CAD patients.

Meta-analysis of trimetazidine treatment for cardiomyopathy.

To explore the effect of trimetazidine (TMZ) in cardiomyopathy treatment. Literatures, related with TMZ treatment for cardiomyopathy, were retrieved between 1990 and February 2018 in the Pubmed, Embase, and Cochrane Library systems. Cardiopulmonary exercise testing [resting heart rate (RHR), peak heart rate (PHR), peak systolic blood pressure (PSBP), and resting systolic blood pressure (RSBP)] and echocardiographic results [left ventricular ejection fraction (LVEF), left ventricular end-systolic volume (LVESV), left ventricular end-diastolic volume (LVEDV), systolic wall thickening score index (SWTSI), left ventricular end-systolic diameter (LVESD), and left ventricular end-diastolic diameter (LVEDD)] were merged to detect the publication bias. Total 898 patients with cardiomyopathy were divided into two groups: TMZ-treated group (n=456) and control group (n=442). There was no difference in the improvement of cardiomyopathy between the TMZ and control group. No publication bias was shown for PHR (t= 0.9791, P=0.5067). There were significant differences in LVEF, LVESV, SWTSI, LVESD, and LVEDD between the TMZ group and the control group. TMZ-treatment significantly increased the level of LVEF (95% confidence interval (CI): 5.46-7.84, P<0.001), and reduced the level of LVESV (95% CI: -18.73 to -7.77, P<0.001), SWTSI (95% CI: -0.47 to -0.15, Z = -3.85, P=0.001), LVESD (95% CI: -1.09 to -0.08, P<0.001), and LVEDD (95% CI: -0.55 to -0.26, P=0.023). There was no publication bias except for LVEDV (t = 2.5456, P=0.0438). TMZ is effective for cardiomyopathy treatment and worth to popularize in clinic.

The evolution of mitral valve prolapse: insights from the Framingham Heart Study.

The Framingham Heart Study group has described the non-diagnostic variants may evolve into mitral valve prolapse over time. These non-diagnostic variants include minimal systolic displacement, and abnormal anterior coaptation which is measured on surface echocardiography. Computed tomography and cardiac magnetic resonance imaging are evolving and can assess the degree of mitral regurgitation (MR); imaging techniques aside, genetic and proteomic detection of mitral prolapse is also evolving. However, the genetic basis for mitral prolapse is complex and likely involves multiple genetic loci. The same is also true for work determining possible biomarkers associated with mitral prolapse. The present study may be useful in counseling patients with a family history of mitral prolapse. Registry data is therefore of paramount importance in providing unbiased insight into this common disease.

Independent risk factors for hypoxemia after surgery for acute aortic dissection.

OBJECTIVES: To determine risk factors associated with postoperative hypoxemia after surgery for acute type A aortic dissection. METHODS: We retrospectively analyzed the clinical data of 192 patients with acute type A aortic dissection who underwent surgery in Qingdao Municipal Hospital, Medical College of Qingdao University, Qingdao, China between January 2007 and December 2013. Patients were divided into hypoxemia group (n=55) [arterial partial pressure of oxygen (PaO2)/fraction of inspired oxygen (FiO2) ≤ 200 mm Hg] and non-hypoxemia group (n=137) [PaO2/FiO2 > 200 mm Hg]. Perioperative clinical data were analyzed and compared between the 2 groups. RESULTS: The incidence of postoperative hypoxemia after surgery for acute aortic dissection was 28.6% (55/192). Perioperative death occurred in 13 patients (6.8%). Multivariate regression identified body mass index (BMI) > 25 kg/m2 (OR=21.929, p=0.000), deep hypothermic circulatory arrest (DHCA) (OR=11.551, p=0.000), preoperative PaO2/FiO2 ≤ 300 mm Hg (OR=7.830, p=0.000) and blood transfusion > 6U in 24 hours postoperatively (OR=12.037, p=0.000) as independent predictors of postoperative hypoxemia for patients undergoing Stanford A aortic dissection surgery. CONCLUSION: Our study demonstrated that BMI > 25 kg/m2, DHCA, preoperative PaO2/FiO2 ≤ 300 mm Hg, and blood transfusion in 24 hours postoperatively > 6U were independent risk factors of the hypoxemia after acute type A aortic dissection aneurysm surgery.

Independent risk factors for ventilator-associated pneumonia after cardiac surgery.

OBJECTIVE: To investigate the related factors and pathogens of ventilator-associated pneumonia (VAP) after heart surgery so as to provide evidences for clinical prevention and therapy. METHODS: In total 1,688 cases were collected from January 2004 to January 2011. Overall 105 patients developed VAP. Retrospectively analyzed these patients after heart surgery to determine the clinical data, pathogens and treatment measures. RESULTS: The frequency of ventilator-associated pneumonia was 6.2% (105/1 688), and mortality was 25.7% (27/105), 198 pathogen strains were isolated by bacterial culture, in which Gram negative bacteria accounted for 69.2% (137/198), Gram positive bacteria 27.8% (55/198), and fungi 3.0% (6/198). The independent risk factors for VAP after cardiac surgery were: age >70 (p < .01), emergent surgery (p < .01), perioperative blood transfusions (p < 0.01), reintubation (p < .01) and days of mechanical ventilation (MV) (p < .01). Median length of stay in the ICU for patients who developed VAP or not was, respectively, (24.7 ± 4.5) days versus (3.2 ± 1.5) days (p < .05), and mortality was, respectively, 25.7% versus 2.9% in both populations (p < .05). CONCLUSION: Age >70, emergent surgery, perioperative blood transfusions, reintubation and days of MV are the risk factors for VAP in patients following cardiac surgery. P. aeruginosa, P. klebsiella, S. aureus, and Acinetobacter baumannii were the main pathogens of VAP. According to the cause of VAP, active prevention and treatment measures should be developed and applied to shorten the time of MV and improve chances of survival.

Perioperative levosimendan therapy is associated with a lower incidence of acute kidney injury after cardiac surgery: a meta-analysis.

OBJECTIVE: Levosimendan is a calcium sensitizer that enhances myocardial contractility without increasing myocardial oxygen use. Limited data are available on its renal-protective effect, and no statistically significant effects have been found. A meta-analysis was conducted for randomized studies to show whether perioperative levosimendan use could reduce acute kidney injury (AKI) in patients undergoing cardiac surgery. DATA SOURCES: BioMed Central, PubMed EMBASE, and the Cochrane Central Register of Controlled Trials were searched for pertinent studies. STUDY SELECTION: Randomized trials that compared levosimendan versus placebo or any other control in cardiac surgery with data on AKI were included. Exclusion criteria were duplicate publications, nonadult studies, oral administration of levosimendan, and studies with no data on AKI. DATA EXTRACTION: Study endpoints, study design, population, clinical setting, levosimendan dosage, and treatment duration were extracted. DATA SYNTHESIS: Data from 529 patients in 5 randomized trials were analyzed. The analysis showed that levosimendan decreased postoperative incidence of AKI in the levosimendan group. CONCLUSIONS: This analysis suggests that levosimendan might reduce renal injury in adult patients undergoing cardiac surgery. More prospective randomized studies are needed to further demonstrate the benefits of levosimendan on renal protection in cardiac surgery.

[Clinical analysis of 105 cases of ventilator-associated pneumonia after heart surgery].

OBJECTIVE: To investigate the related factors and pathogens of ventilator-associated pneumonia (VAP) after heart surgery. METHODS: VAP was diagnosed in 105 patients out of 1688 cases (6.2%) who underwent heart surgery in our department between January 2004 and January 2011. Clinical data, pathogens and treatments were analyzed. RESULTS: Incidence of VAP was 6.2% (105/1688), and 53.0% (105/198) in patients who required more than 48 hours of mechanical ventilation. One hundred and ninety-eight pathogen strains were isolated by bacterial culture, in which Gram negative bacteria accounted for 69.2% (137/198), Gram positive bacteria 27.8% (55/198), and fungi for 3.0% (6/198). Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumannii, Escherichia coli, and Staphylococcus aureus were the main pathogens of VAP. The independent risk factors for VAP were: age > 70 years, emergent surgery, perioperative transfusions, reintubation and days of mechanical ventilation (all P < 0.01). Median length of stay in the ICU for patients who developed VAP or not was (24.7 ± 4.5) days versus (3.2 ± 1.5) days, respectively (P < 0.05) and in-hospital mortality was 25.7% (27/105) versus 2.9% (46/1583) respectively (P < 0.05). CONCLUSIONS: Patients undergoing heart surgery have a high frequency of developing VAP, especially in patients that require more than 48 hours of mechanical ventilation. VAP is associated with high in-hospital mortality. Age > 70 years, emergent surgery, perioperative transfusions, reintubation and prolonged mechanical ventilation use are independent risk factors for VAP in patients following cardiac surgery. Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumannii, Escherichia coli, and Staphylococcus aureus are the main pathogens of VAP.