Impact of prosthesis-patient mismatch on early and late outcomes after mitral valve replacement: a meta-analysis.

BACKGROUND: Prognostic significance of prosthesis-patient mismatch (PPM) after mitral valve replacement (MVR) remains uncertain because of the limited studies reporting inconsistent or even contrary results. This meta-analysis pooled results of all available studies comparing early and late prognoses between patients with significant mitral PPM and those without. METHODS: Studies were identified by searching Pubmed, Excerpta Medica Database, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov. Impact of PPM on postoperative hemodynamic results, thirty-day mortality, overall mortality, mortality of thirty-day survivors, and primary morbidity after MVR was evaluated via meta-analysis. Robustness of pooled estimates, source of heterogeneity, and publication bias were assessed via sensitivity analyses, meta-regression as well as subgroup analysis stratified according to methodological or clinical heterogeneity, or sequential omission method, and funnel plot or Begg's and Egger's tests, respectively. RESULTS: Nineteen cohort studies involving 9302 individuals (PPM group: n = 5109, Control group: n = 4193) were included for meta-analysis. Total PPM and severe PPM prevalence were 3.8%-85.9% and 1%-27%, with a mean value of 54.9% and 14.1%, respectively. As compared with control group, mitral PPM group demonstrated a poorer postoperative hemodynamic status of higher mean and peak residual transprosthetic pressure gradients (TPG), higher postoperative systolic pulmonary artery pressure (SPAP) and less reduction, higher postoperative pulmonary hypertension (PH) prevalence and less PH regression, smaller net atrioventricular compliance, less NYHA class decrease, higher postoperative functional tricuspid regurgitation prevalence and less regression. The PPM group also revealed a higher thirty-day mortality, long-term overall mortality, mortality of thirty-day survivors, and postoperative congestive heart failure prevalence, which were positively correlated with the severity of PPM if it was classified into tri-level subgroups. Left ventricular end-diastolic diameter, postoperative atrial fibrillation (AF) prevalence, and the AF regression were analogous between groups. Most pooled estimates were robust according to sensitivity analyses. Male patients and bioprosthesis implantation proportion were prominent source of between-study heterogeneity on thirty-day mortality. Publication bias was not significant in tests for all the outcomes, except for SPAP and TPG. CONCLUSIONS: Mitral PPM would result in poorer postoperative hemodynamics and worse early and late prognosis. Severe PPM must be avoided since deleterious impact of mitral PPM was severity dependent.

Surgical Outcomes of Stent-Related Type A Dissection Compared with Spontaneous Type A Dissection.

OBJECTIVE: Aortic endovascular stent implantation includes thoracic endovascular aortic repair (TEVAR), hybrid aortic repair (HAR), and ascending aorta stent implantation (AASI). In this study, we compared the surgical outcomes of stent-related type A dissection (SRTAD) compared with spontaneous type A dissection (STAD). METHODS: From July 2011 to July 2014, we identified 17 SRTAD patients received surgical repair in our institution. Propensity score-matching was used to identify 34 STAD patients as controls. RESULTS: Preoperative data of SRTAD group and STAD group had no statistical difference. Selective cerebral perfusion (SCP) time was longer in SRTAD group than in STAD group (P <0.05). SRTAD group had a longer cross-clamp time compared with STAD group (P <0.05). No intraoperative deaths in two groups. No differences in CPB time and concomitant procedures between two groups. In-hospital mortality was 11.76% (2 of 17) in SRTAD group and 2.9% (1 of 34) in STAD group (P <0.05). No differences were found in intensive care unit (ICU) time, ventilation, paraparesis, and other postoperative complications between SRTAD and STAD groups. No difference was found in survival rate between SRTAD and STAD groups in the postoperative 1-year follow-up. CONCLUSIONS: SRTAD patients received surgical repair had a higher in-hospital mortality compared with STAD, but no differences were found in postoperative complications and mid-term outcomes.

Retrograde Type A Dissection after Ascending Aorta Involved Endovascular Repair and Its Surgical Repair with Stented Elephant Trunk.

BACKGROUND: Retrograde type A dissection (RTAD) is a serious complication after ascending aorta involved endovascular repair (AAIER). We here report our surgical approach to this serious complication. METHODS: From July 2011 to July 2014, 8 RTADs after AAIER patients received surgical repair in our institution. Data of these RTAD patients were retrospectively collected for further analysis. All patients received urgent surgical repair based on the stented elephant trunk technique. We took 2 different ways to handle the previous stent during operation. In patients who had a prior hybrid aortic repair, we removed the proximal part of the stent while the distal part was left in place. In patients who had prior ascending aorta stent implantation (AASI), the stent was totally removed. RESULTS: The mean age of the patients was 57.6 ± 11.9 years. Regarding the index intervention, 2 patients received hybrid aortic repair and 6 patients received AASI. In patients who received AASI, 1 patient underwent simultaneous thoracic endovascular aortic repair (TEVAR) and another patient received simultaneous chimney technique in innominate artery and left common carotid artery combined with bypass from left subclavian artery to left common carotid artery to cure the type I endoleak induced by the previous implanted TEVAR stent. All patients received a new elephant trunk implantation during surgical repair. The mean cardiopulmonary bypass, selective cerebral perfusion, and aortic cross-clamp time were 172.1 ± 13.3, 40.8 ± 4.2, and 121.8 ± 11.4 min, respectively. The mean intensive care unit time was 7.8 ± 3.4 days. Two patients (25.0%) experienced transient neurologic dysfunction and recovered completely before discharge. In-hospital death rate was 12.5% (1 of 8). The mean follow-up time was 17.1 ± 9.5 months. No late deaths or complications occurred during follow-up. CONCLUSIONS: AAIER especially AASI used in aortic dissection treatment should be seriously considered since RTAD might occur. Our study indicated that surgical repair with stented elephant trunk was feasible and according to the cause of RTAD, different surgical strategies should be taken to manage the stent.

Involvement of Oct4 in the pathogenesis of thoracic aortic dissection via inducing the dedifferentiated phenotype of human aortic smooth muscle cells by directly upregulating KLF5.

OBJECTIVE: To investigate the expression of Oct4 in human thoracic aortic dissection (TAD) and the regulation mechanisms of Oct4 on phenotype transition of human aortic smooth muscle cells (HASMCs). METHODS: Aortic samples from TAD patients (n = 12) and organ donors (n = 6) were collected. qRT-PCR, western blot, and immunohistochemistry were performed to identify Oct4 expression in aortic media. Immunofluorescence was performed to analyze Oct4 expression in primary HASMCs. Oct4A and Oct4B isoforms were detected. Gain-of-function experiments were performed to determine the effects of Oct4 on HASMC phenotype transition. Chromatin immunoprecipitation, luciferase assay, and rescue experiments were performed to analyze mechanisms of Oct4 on HASMC phenotype transition. RESULTS: Oct4 expression levels, especially the Oct4A isoform, were significantly higher in TAD patients compared with normal controls. Notably, Oct4 presented a strong and strict nuclear localization in primary HASMCs of TAD patients but a mild and diffuse distribution in both cytoplasm and nucleus in the control group. Overexpression of Oct4 induced dedifferentiation of HASMCs characterized by decreased contractile proteins and elevated migration capability. Krüppel-like factor 5 (KLF5) was found to be a directly regulated target gene of Oct4 in HASMCs. Furthermore, downregulation of KLF5 significantly alleviated the effects of Oct4 on phenotype transition of HASMCs. CONCLUSIONS: Oct4 expression was significantly upregulated in aortic tissues and primary HASMCs of TAD patients. The increased Oct4 induced phenotype transition of HASMCs from the contractile type to the synthetic type by directly upregulating KLF5.

Proximal aortic repair versus extensive aortic repair in the treatment of acute type A aortic dissection: a meta-analysis.

OBJECTIVES: The optimal surgical strategy for acute type A aortic dissection (ATAAD) is still controversial because of the inconsistent or even conflicting results of proximal aortic repair (PR) versus extensive aortic repair (ER) on early and late prognostic outcomes. This meta-analysis pooled data from all available studies of PR versus ER to get a summarized conclusion. METHODS: Studies were identified by searching the Medline, EMBASE and Cochrane databases. Early and late prognostic outcomes of interest were evaluated with meta-analysis. Fixed- or random-effect models were used according to the significance of heterogeneity. Robustness of pooled estimates and the source of heterogeneity were assessed via sensitivity analyses and meta-regression, respectively. Publication bias was evaluated by the funnel plot and Egger's test. RESULTS: Nine studies with a total of 1872 patients were included for the meta-analysis. Pooled results indicated that, when compared with the ER procedure, PR was associated with lower early mortality [risk ratio (RR) = 0.69, 95% confidence interval (CI) 0.54-0.90, P = 0.005] but higher incidence of postoperative aortic events including reoperation of the distal aorta (RR = 3.14, 95% CI 1.74-5.67, P < 0.001). PR and ER demonstrated analogous prognosis on long-term mortality (HR = 1.02, 95% CI 0.51-2.06, P = 0.96) and the incidences of early postoperative renal failure (RR = 0.75, 95% CI 0.49-1.14, P = 0.17) and stroke (RR = 0.73, 95% CI 0.30-1.78, P = 0.50). All the pooled results were robust to sensitivity analysis. Heterogeneity was insignificant except for the meta-analysis of late mortality. CONCLUSIONS: Performing a less aggressive initial surgical procedure of PR in ATAAD patients would have lower early mortality but elevated incidence rates of late aortic reintervention, when compared with ER. Other prognostic results of the two surgical strategies including long-term mortality were similar for both.

Brahma-related gene 1 inhibits proliferation and migration of human aortic smooth muscle cells by directly up-regulating Ras-related associated with diabetes in the pathophysiologic processes of aortic dissection.

OBJECTIVE: To elucidate the mechanisms of Brahma-related gene 1 (Brg1) involvement in the pathophysiologic processes of aortic dissection. METHODS: Seventeen dissecting, 4 dilated, and 10 healthy human aorta samples were collected. Expression of Brg1 in the medium of aorta was evaluated by quantitative real-time polymerase chain reaction, Western blot, and immunohistochemical staining, respectively. The regulation effect of Brg1 on proliferation and migration of human aortic smooth muscle cells (HASMCs) was analyzed in 3 ways: using cell counting, a migration chamber, and a wound scratch assay. A polymerase chain reaction array was used for screening potential target genes of Brg1. A chromatin immunoprecipitation assay was adopted for direct deoxyribonucleic acid-protein binding detection. RESULTS: Expression levels of Brg1 were increased in aortic dissection and aortic dilation patients. In vitro results indicated that overexpression of Brg1 inhibited proliferation and migration of HASMCs. The candidate proliferation- and migration-related Brg1 target gene found was Ras-related associated with diabetes (RRAD), expression levels of which were enhanced in dissecting aortic specimens. The direct regulation effect of Brg1 on RRAD was verified by chromatin immunoprecipitation assay results. Furthermore, down-regulating RRAD significantly alleviated the suppression effects of Brg1 on proliferation and migration of HASMCs. CONCLUSIONS: Our study illustrated that Brg1 inhibited the proliferation and migration capacity of HASMCs, via the mechanism of direct up-regulation of RRAD, thus playing an important role in the pathophysiologic processes of aortic dissection.

Society of Thoracic Surgeons 2008 cardiac risk models predict in-hospital mortality of heart valve surgery in a Chinese population: a multicenter study.

OBJECTIVES: The Society of Thoracic Surgeons 2008 cardiac surgery risk models have been developed for heart valve surgery with and without coronary artery bypass grafting. The aim of our study was to evaluate the performance of Society of Thoracic Surgeons 2008 cardiac risk models in Chinese patients undergoing single valve surgery and the predicted mortality rates of those undergoing multiple valve surgery derived from the Society of Thoracic Surgeons 2008 risk models. METHODS: A total of 12,170 patients underwent heart valve surgery from January 2008 to December 2011. Combined congenital heart surgery and aortal surgery cases were excluded. A relatively small number of valve surgery combinations were excluded. The final research population included the following isolated heart valve surgery types: aortic valve replacement, mitral valve replacement, and mitral valve repair. The following combined valve surgery types were included: mitral valve replacement plus tricuspid valve repair, mitral valve replacement plus aortic valve replacement, and mitral valve replacement plus aortic valve replacement and tricuspid valve repair. Evaluation was performed by using the Hosmer-Lemeshow test and C-statistics. RESULTS: Data from 9846 patients were analyzed. The Society of Thoracic Surgeons 2008 cardiac risk models showed reasonable discrimination and poor calibration (C-statistic, 0.712; P = .00006 in Hosmer-Lemeshow test). Society of Thoracic Surgeons 2008 models had better discrimination (C-statistic, 0.734) and calibration (P = .5805) in patients undergoing isolated valve surgery than in patients undergoing multiple valve surgery (C-statistic, 0.694; P = .00002 in Hosmer-Lemeshow test). Estimates derived from the Society of Thoracic Surgeons 2008 models exceeded the mortality rates of multiple valve surgery (observed/expected ratios of 1.44 for multiple valve surgery and 1.17 for single valve surgery). CONCLUSIONS: The Society of Thoracic Surgeons 2008 cardiac surgery risk models performed well when predicting the mortality for Chinese patients undergoing valve surgery. The Society of Thoracic Surgeons 2008 models were suitable for single valve surgery in a Chinese population; estimates of mortality for multiple valve surgery derived from the Society of Thoracic Surgeons 2008 models were less accurate.

Measurement of oxygen consumption in children undergoing cardiac catheterization: comparison between mass spectrometry and the breath-by-breath method.

Accurate measurement of oxygen consumption (VO2) is important to precise calculation of blood flow using the Fick equation. This study aimed to validate the breath-by-breath method (BBBM) of measuring oxygen consumption VO2 compared with respiratory mass spectroscopy (MS) for intubated children during cardiac catheterization. The study used MS and BBBM to measure VO2 continuously and simultaneously for 10 min in consecutive anesthetized children undergoing cardiac catheterization who were intubated with a cuffed endotracheal tube, ventilated mechanically, and hemodynamically stable, with normal body temperature. From 26 patients, 520 data points were obtained. The mean VO2 was 94.5 ml/min (95 % confidence interval [CI] 65.7-123.3 ml/min) as measured by MS and 91.4 ml/min (95 % CI 64.9-117.9 ml/min) as measured by BBBM. The mean difference in VO2 measurements between MS and BBBM (3.1 ml/min; 95 % CI -1.7 to +7.9 ml/min) was not significant (p = 0.19). The MS and BBBM VO2 measurements were highly correlated (R (2) = 0.98; P < 0.0001). Bland-Altman analysis showed good correspondence between MS and BBBM, with a mean difference of -3.01 and 95 % limits of agreement ranging from -26.2 to +20.0. The mean VO2 indexed to body surface area did not differ significantly between MS and BBBM (3.4 ml/min m(2); 95 % CI -1.4 to 8.2; p = 0.162). The mean difference and limits of agreement were -3.8 ml/min m(2) (range, -19.9 to 26.7). Both MS and BBBM may be used to measure VO2 in anesthetized intubated children undergoing cardiac catheterization. The two methods demonstrated excellent agreement. However, BBBM may be more suited to clinical use with children.

[Recombinant adeno-associated virus mediated RNA interference of angiogenin expression inhibits cell growth of human lung adenocarcinoma].

OBJECTIVE: To study the inhibition of angiogenin (ANG) expression in human lung squamous cancer cell strain-A549 through adeno-associated virus (AAV)-mediated RNA-interference, and therefore to observe its effect on the growth of cancer cells and tumor formation. METHODS: Recombinant AAV expressing H1-promoter-induced small-interference- RNA (siRNA) targeting ANG (AAV-shANG) was constructed, and then transfected into A549 cells. A549 cells and cells transfected with AAV-Null were used as the control groups. The effects of the reduced expression of ANG by RNAi from AAV-shANG on the growth, formation, reproduction, apoptosis, and microvessel-density of the carcinoma were observed. RESULTS: In vitro experiment showed that AAV-shANG was constructed successfully, There was an significant decrease in the expression of ANG protein 72 h after transfection, compared with the normal A459 cells and AAV-Null cells (P < 0.01). Cell cycle analysis showed that the proliferation index (PI) of normal A549 cells, AAV-Null cells and AAVshANG cells were 0.32 +/- 0.29, 0.35 +/- 0.38 and 0.31 +/- 0.43, respectively. There was no statistic difference in the PIs among the 3 groups (P > 0.05). In vivo experiment using thymus-defect mice showed that, there was an remarkable reduction in the mass and volume of tumors in AAV-shANG transfected group, compared to the control groups. Microvessel-density was 9.4 +/- 1.5, 9.8 +/- 2.1 and 5.7 +/- 1.9, respectively in the 3 groups, a statistic difference among the AAV-shANG-transfected group, the normal A549 group and the AAV-Null transfected group. The percentages of apoptotic cells in each group were (7.7 +/- 3.1)%, (8.5 +/- 5.4)%, (17.1 +/- 8.6)%, respectively, the experimental group being higher than those of the control groups. Positive rates of PCNA were (84.8 +/- 9.7)%, (85.8 +/- 9.8)%, and (70.4 +/- 10.1)%, respectively, the AAV-shANG transfected cancer cells showing a lower PCNA index than the control groups. CONCLUSION: AAV-mediated expression of siRNA could reduce the expression of ANG in cancer cells, significantly enough to inhibit cell proliferation, promote cell apoptosis and inhibit tumor growth.