Propensity score (PS) methods offer certain advantages over more traditional regression methods to control for confounding by indication in observational studies. Although multivariable regression ...models adjust for confounders by modelling the relationship between covariates and outcome, the PS methods estimate the treatment effect by modelling the relationship between confounders and treatment assignment. Therefore, methods based on the PS are not limited by the number of events, and their use may be warranted when the number of confounders is large, or the number of outcomes is small. The PS is the probability for a subject to receive a treatment conditional on a set of baseline characteristics (confounders). The PS is commonly estimated using logistic regression, and it is used to match patients with similar distribution of confounders so that difference in outcomes gives unbiased estimate of treatment effect. This review summarizes basic concepts of the PS matching and provides guidance in implementing matching and other methods based on the PS, such as stratification, weighting and covariate adjustment.
In a patient-level combined analysis of six randomized trials, the use of radial-artery grafts for CABG, as compared with the use of saphenous-vein grafts, resulted in a lower rate of adverse cardiac ...events and a higher patency rate at 5 years of follow-up.
An old off-pump coronary artery bypass surgeon's reflections: A retrospective Angelini, Gianni D.
Journal of thoracic and cardiovascular surgery/The Journal of thoracic and cardiovascular surgery/The journal of thoracic and cardiovascular surgery,
June 2019, 2019-06-00, 20190601, Letnik:
157, Številka:
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Journal Article
In this study, patients were randomly assigned to a transfusion threshold of 9 or 7.5 g per deciliter after cardiac surgery. There was no significant between-group difference in infectious or ...ischemic events, but more deaths were associated with the lower threshold.
Perioperative anemia is common after cardiac surgery and is associated with significant increases in morbidity and mortality.
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The transfusion of allogeneic red cells is the preferred treatment for acute anemia and is also used in patients undergoing cardiac surgery; typically, more than 50% of patients receive a perioperative transfusion,
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which uses a substantial proportion of blood supplies.
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Observational studies suggest that transfusion is harmful after cardiac surgery; associations have been reported between transfusion and infection, low cardiac output, acute kidney injury, and death.
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In contrast, randomized, controlled trials of red-cell transfusion with restrictive thresholds (i.e., transfusions . . .
Exosome nanoparticles carry a composite cargo, including microRNAs (miRs). Cultured cardiovascular cells release miR-containing exosomes. The exosomal trafficking of miRNAs from the heart is largely ...unexplored. Working on clinical samples from coronary-artery by-pass graft (CABG) surgery, we investigated if: 1) exosomes containing cardiac miRs and hence putatively released by cardiac cells increase in the circulation after surgery; 2) circulating exosomes and exosomal cardiac miRs correlate with cardiac troponin (cTn), the current "gold standard" surrogate biomarker of myocardial damage.
The concentration of exosome-sized nanoparticles was determined in serial plasma samples. Cardiac-expressed (miR-1, miR-24, miR-133a/b, miR-208a/b, miR-210), non-cardiovascular (miR-122) and quality control miRs were measured in whole plasma and in plasma exosomes. Linear regression analyses were employed to establish the extent to which the circulating individual miRs, exosomes and exosomal cardiac miR correlated with cTn-I. Cardiac-expressed miRs and the nanoparticle number increased in the plasma on completion of surgery for up to 48 hours. The exosomal concentration of cardiac miRs also increased after CABG. Cardiac miRs in the whole plasma did not correlate significantly with cTn-I. By contrast cTn-I was positively correlated with the plasma exosome level and the exosomal cardiac miRs.
The plasma concentrations of exosomes and their cargo of cardiac miRs increased in patients undergoing CABG and were positively correlated with hs-cTnI. These data provide evidence that CABG induces the trafficking of exosomes from the heart to the peripheral circulation. Future studies are necessary to investigate the potential of circulating exosomes as clinical biomarkers in cardiac patients.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract Background Although generally better outcomes are reported in patients undergoing early repair of type A aortic dissection, patients who survive the first 48 hours self-select themselves ...toward better outcomes as well. Malperfusion is another important determinant of outcome in these patients. The aim of this study was to examine the hypothesis that malperfusion, not the timing of operation, is the dominant determinant of outcome in repair of type A aortic dissection. Methods A total of 205 patients underwent operative repair of acute type A aortic dissection in our hospital over a 17-year period. The time from symptom onset to surgical repair was reliably established in 152 cases. Patients were grouped into those who had undergone surgery within 12 hours of symptom onset (early surgery group; n = 72 47%) and those who underwent surgery beyond 12 hours of symptom onset (late surgery group; n = 80 53%). Results Thirty-day mortality was similar in the 2 groups (early surgery: 19.4% 95% confidence interval CI 12.0%-30.6%; late surgery: 13.8% 95% CI, 7.9%-23.5%; P = .08). The log-rank test for equality of survivor functions was 0.08. However, malperfusion with hemodynamic compromise was more common in the early surgery group (47% vs 31%; P = .029) and was identified as an independent predictor of long-term mortality (hazard ratio, 2.65; 95% CI, 1.21-5.79; P = .014). Conclusions Malperfusion at presentation rather than timing of intervention is the major risk factor of death both in the hospital and at long-term follow-up in patients undergoing surgery for type A aortic dissection.
Interest in the usefulness of machine learning (ML) methods for outcomes prediction has continued to increase in recent years. However, the advantage of advanced ML model over traditional logistic ...regression (LR) remains controversial. We performed a systematic review and meta-analysis of studies comparing the discrimination accuracy between ML models versus LR in predicting operative mortality following cardiac surgery.
The present systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement. Discrimination ability was assessed using the C-statistic. Pooled C-statistics and its 95% credibility interval for ML models and LR were obtained were obtained using a Bayesian framework. Pooled estimates for ML models and LR were compared to inform on difference between the 2 approaches.
We identified 459 published citations of which 15 studies met inclusion criteria and were used for the quantitative and qualitative analysis. When the best ML model from individual study was used, meta-analytic estimates showed that ML were associated with a significantly higher C-statistic (ML, 0.88; 95% credibility interval, 0.83-0.93 vs LR, 0.81; 95% credibility interval, 0.77-0.85; P = .03). When individual ML algorithms were instead selected, we found a nonsignificant trend toward better prediction with each of ML algorithms. We found no evidence of publication bias (P = .70).
The present findings suggest that when compared with LR, ML models provide better discrimination in mortality prediction after cardiac surgery. However, the magnitude and clinical influence of such an improvement remains uncertain.
Machine learning versus logistic regression model for mortality prediction in cardiac surgery. Display omitted
Abstract Background There are several options available for aortic valve replacement (AVR), with few comparative reports in the literature. The optimal choice for AVR in each age group is not clear. ...Objectives The study sought to report and compare outcomes after AVR in the young using data from a national database. Methods AVR procedures were compared after advanced matching, both in pairs and in a 3-way manner, using a Bayesian dynamic survival model. Results A total of 1,501 patients who underwent AVR in the United Kingdom between 2000 and 2012 were included. Of these, 47.8% had a Ross procedure, 37.8% a mechanical AVR, 10.9% a bioprosthesis AVR, and 3.5% a homograft AVR, with Ross patients being significantly younger when compared to the other groups. Overall survival at 12 years was 94.6%. In children, the Ross procedure had a 12.7% higher event-free probability (death or any reintervention) at 10 years when compared to mechanical AVR (p = 0.05). We also compared all procedures except the homograft in a matched population of young adults, where the bioprosthesis had the lowest event-free probability of 78.8%, followed by comparable results in mechanical AVR and Ross, with 86.3% and 89.6%, respectively. Younger age was associated with mortality and pulmonary reintervention in the Ross group and with aortic reintervention in the mechanical AVR. Of all 3 options, only the patients undergoing the Ross procedure approached the survival of the general population. Conclusions AVR in the young achieves good results, with the Ross being overall better suited for this age group, especially in children. Although freedom from aortic valve reintervention is superior after the Ross procedure, the need for homograft reinterventions is an issue to take into account. All methods have advantages and limitations, with reinterventions being an issue in the long term for all, more crucially in smaller children.
Despite advances in cardiac surgery, observational studies suggest that females have poorer post-operative outcomes than males. This study is the first to review sex related outcomes following both ...coronary artery bypass graft (CABG) and valve surgery with or without combined CABG.
We identified 30 primary research articles reporting either short-term mortality (in-hospital/30 day), long-term mortality, and post-operative stroke, sternal wound infection and myocardial infarction (MI) in both sexes following CABG and valve surgery with or without combined CABG. Reported adjusted odds/hazard ratio were pooled using an inverse variance model.
Females undergoing CABG and combined valve and CABG surgery were at higher risk of short-term mortality (odds ratio (OR) 1.40; 95% confidence interval (CI) 1.32–1.49; I2 = 79%) and post-operative stroke (OR 1.2; CI 1.07–1.34; I2 = 90%) when compared to males. However, for isolated AVR, there was no difference found (OR 1.19; 95% CI 0.74–1.89). There was no increased risk in long-term mortality (OR 1.04; 95% CI: 0.93–1.16; I2 = 82%), post-operative MI (OR 1.22; 95%CI: 0.89–1.67; I2 = 60%) or deep sternal wound infection (OR 0.92; 95%CI: 0.65–1.03, I2 = 87%). No evidence of publication bias or small study effect was found.
Females are at a greater risk of short-term mortality and post-operative stroke than males following CABG and valve surgery combined with CABG. However, there is no difference for Isolated AVR. Long-term mortality is equivalent in both sexes.
PROSPERO Registration: CRD42021244603.
•Female sex is thought to be a risk factor for mortality and morbidity after cardiac surgery•This study is the first to review sex related outcomes following both coronary artery bypass graft (CABG) and valve surgery with or without combined CABG•Females are at a greater risk of short-term mortality and post-operative stroke than males following CABG and valve surgery combined with CABG•Following isolated aortic valve replacement, there is no difference in outcomes•Long-term mortality is equivalent in both sexes
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