Thiamine as an outcome predictor in postoperative CABG patients

Introduction

Coronary artery bypass graft surgery (CABG) is one of the most performed cardiovascular procedures worldwide. Despite good outcomes, CABG induces systemic inflammation, increases oxidative stress and increases catabolism. As thiamine act as a cofactor in glucose metabolism and glutathione synthesis, its deficiency could have a high prevalence in critically ill patients.

Purpose

To assess the association between plasma thiamine concentrations and clinical outcomes and 30-day mortality in patients undergoing non-emergency CABG.

Methods

Prospective and observational study that included consecutive patients older than 18 years undergoing CABG that assigned the consent form. Plasma thiamine concentrations were determined before and 24 hours after the procedure by the high-performance liquid chromatography method. The clinical outcomes evaluated were perioperative acute myocardial infarction, heart failure, cardiogenic shock, arrhythmias, stroke and acute kidney injury. Mortality was evaluated on the 30th day after CABG.

Results

The study included 131 patients submitted to CABG. The mean age was 61±9.1 years, 73.3% were men, and the mean EuroScore II value was 1.78±1.3%. Before CABG, plasmatic thiamine concentration was 33±15ng/ml, and 15% of the patients had thiamine deficiency. After CABG, plasmatic thiamine concentration was 20±8ng/ml. All patients diminished plasmatic thiamine concentration after CABG. Mortality was 16% and 24% of patients presented acute kidney injury. Combined outcomes, which included the presence of acute myocardial infarction, heart failure, cardiogenic shock, arrhythmias, stroke, acute kidney injury or death, was present in 52% of the patients. Percentage of thiamine variation between before and after CABG was not associated with mortality (34±14 vs 41±10%; p=0.063); however, it was associated with acute kidney injury (40±14 vs 34±13%; p=0.027) and combined outcomes (37±13 vs 33±14%; p=0.035).

Conclusion

Percentage of thiamine variation from before to after CABG was associated with acute kidney injury and combined outcomes in these patients.

Funding Acknowledgement

Type of funding sources: None.

Multimodality imaging and systemic biomarkers in classical low-flow low-gradient aortic stenosis: key findings for cardiac remodeling evaluation

Background

Elevated levels of troponin I (hsTnT) and B-type natriuretic peptide (BNP) have been related with poor prognosis in patients with LFLG-AS. Biomarkers are less expensive, more practical and more accessible than imaging tests, so their use can be an alternative to imaging in the evaluation of patients with LFLG-AS.

Purpose

The aim of the present study is to assess multimodality imaging findings according to systemic biomarkers (i.e. hsTnT and BNP) in Low-Flow, Low-Gradient Aortic Stenosis (LFLG-AS) and reduced left ventricular ejection fraction (LVEF) patients.

Methods

Prospective study with LFLG-AS patients (LVEF <50%, aortic valve area ≤1,0 cm2 and mean gradient <40 mmHg) that underwent hsTNnT, BNP, cardiac magnetic resonance (CMR) with T1 mapping and 2 dimensional echocardiogram (2DEcho). All patients also underwent dobutamine stress echocardiogram to define aortic stenosis severity. Patients were divided into 3 groups according to BNP and hsTnT levels: Group 1: BNP and hsTnT levels below median (BNP <395 pg/ml and TnI-Ultra <0.042 ng/ml); Group 2: BNP or hsTnT higher than median; and Group 3: both hsTnT and BNP higher than median.

Results

49 patients with LFLG-AS were included (Group 1: 17 patients, Group 2: 14 patients and Group 3: 18 patients). Clinical characteristics (including risk scores) were not able to stratify these groups. Patients with elevation of both biomarkers had lower valvuloarterial impedance (P=0.03), lower LVEF (P=0.02), less moderate/severe mitral (P=0.01) and tricuspid regurgitation (P<0.01) by 2DEcho. CMR identified a progressive increase (from Group 1 to 3) of right and left chamber volumes; reduction in right and left ejection fraction and a marked increase in myocardial fibrosis assessed by extracellular volume (ECV) and indexed extracellular volume (iECV) (Figure 1).

Conclusion

Higher levels of BNP and hsTnT in LFLG-AS patients were associated with worse multi-modality imaging parameters and can be a surrogate of cardiac remodeling.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): No funding

P929Predictors of renal function improvement in patients with chronic kidney disease undergoing TAVR

Background

Chronic kidney disease (CKD) is common among patients undergoing transcatheter aortic valve replacement (TAVR). The prognosis of CKD on TAVR outcomes has been previously documented. However, there is a paucity of data about predictors of renal function improvement and its clinical relevance.

Purpose

To determine predictors of renal function improvement after TAVR among patients with CKD.

Methods

Prospective study, analyzing 819 patients from 22 centers with symptomatic severe aortic stenosis included in the Brazilian TAVR Registry between 2008 and 2015. CKD was defined as estimated glomerular filtration rate (eGFR) <60mg/dL, and patients without CKD were excluded. Groups were divided according to variation of eGFR between baseline and 7 days after TAVR: improvement (increase >10% in eGFR) in 197 (34.1%) patients, worsening (decrease >10% in eGFR) in 203 (35.2%), and stable (neither criteria) in 177 (30.7%). Logistic regression analysis was used to identify predictors of renal function improvement. One-year outcomes were determined as Kaplan-Meier survival curves.

Results

CKD was present in 577 (70%) patients. The mean age was 81.9±6.8 years, 56.2% were male, 31.7% had diabetes and 74.5% had hypertension. The mean STS score was 10.6±7.9%, the mean EuroSCORE II were 21.8±15.2% and the preferable access site was transfemoral (93.4%). The mean eGFR was 37.3±12.5 ml/min in the improvement group (IG), 39.6±11.7 ml/min in the stable group (SG) and 40.2±12.3 ml/min in the worsening group (WG), with significant statistical difference between IG and WG (p=0.044). There was no difference related to contrast midia volume between the 3 groups. In the multivariate analysis, coronary artery disease (OR: 0.69; 95% CI 0.48–0.98; p=0.039) and baseline eGFR (OR: 0.98; 95% CI 0.97–1.00; p=0.039) were associated with improvement in renal function. There was no significant difference in 1-year all-cause mortality between IG and SG (15.4 vs 9.5%, log rank p=0.141) (Figure 1A). However, the WG had higher mortality compared with the IG (29.3 vs 15.4%, log rank p<0,001) (Figure 1B).

Figure 1

Conclusion

Improvement in renal function after TAVR was frequently found among patients with CKD. The absence of coronary artery disease and lower baseline eGFR were independent predictors of improvement in renal function. Although the IG had lower 1-year all-cause mortality compared to WG, no difference were observed related to SG.

Acknowledgement/Funding

SBHCI

Assessment of long-term mortality in patients with complex coronary artery disease undergoing percutaneous intervention: comparison of multiple anatomical and clinical prognostic risk scores

AIMS

Three-vessel and left main coronary artery disease (CAD) have important prognostic implications. Consequently, numerous risk scores have been developed to stratify patients with complex CAD. The aim of the present study was to compare the predictive performance of six risk scores for occurrence of fouryear all-cause mortality.

METHODS AND RESULTS

From March 2008 to December 2012, 348 consecutive patients with complex CAD undergoing percutaneous coronary intervention (PCI) in a tertiary centre in São Paulo, Brazil, were analysed. Four-year mortality was assessed. The scores compared were: baseline SYNTAX score (SS), residual SYNTAX score (rSS), ACEF score, clinical SYNTAX score (cSS), SYNTAX revascularisation index (SRI) and SYNTAX score II (SSII). SSII had the best predictive performance, AUC 0.82, Brier score 0.10, surpassing all the other scores for long-term mortality prediction. Moreover, SSII discriminated well PCI patients in risk groups with p<0.01 for four-year all-cause mortality. The ACEF score (AUC 0.77) and the cSS (AUC 0.78) were significantly better than the SS (AUC 0.65), SRI (AUC 0.60) or the rSS (AUC 0.55).

CONCLUSIONS

For patients with complex CAD treated by PCI, the combination of baseline clinical and angiographic factors provided better risk assessment. The SSII demonstrated the most precise predictive performance for long-term mortality.

Long-term effects of human amniotic membrane in a rat model of biliary fibrosis

Liver fibrosis is the most common outcome of chronic liver diseases, and its progression to cirrhosis can only be effectively treated with liver transplantation. The amniotic membrane (AM) has been studied as an alternative therapy for fibrosis diseases mainly for its favorable properties, including anti-inflammatory, anti-scaring and immunomodulatory properties. It was recently demonstrated that the AM reduces the progression of biliary fibrosis to its advanced stage, cirrhosis, when applied on the liver for 6 weeks after fibrosis induction. Here, we investigated the effects of AM on rat fibrotic liver, during a prolonged period of time. Fibrosis was induced by bile duct ligation (BDL), and at the same time, a fragment of AM was applied around the liver. After 1, 3, 6, and 9 weeks, the degree of fibrosis was assessed by qualitative Knodell scoring, and by quantitative image analysis to quantify the area of collagen deposition in hepatic tissue. While fibrosis progressed rapidly in untreated BDL animals, leading to cirrhosis within 6 weeks, AM-treated livers showed confined fibrosis at the periportal area with few and thin fibrotic septa, but without cirrhosis. In addition, collagen deposition was reduced to about 36 and 55% of levels observed in BDL at 6 and 9 weeks after BDL, respectively, which shows that the longer the period of AM application, the lower the collagen deposition. These results suggested that AM applied as a patch onto the liver surface for longer periods attenuated the severity of biliary fibrosis and protected against liver degeneration caused by excessive collagen deposition.

N-acetylcysteine does not prevent contrast induced nephropathy after cardiac catheterisation with an ionic low osmolality contrast medium: a multicentre clinical trial

OBJECTIVE

To evaluate oral N-acetylcysteine in the prevention of contrast induced nephropathy (CIN) in patients at low to moderate risk undergoing cardiac catheterisation with ionic low osmolality contrast medium.

METHODS

In a multicentre double blind clinical trial 156 patients undergoing coronary angiography or percutaneous coronary intervention with serum creatinine > or = 106.08 micromol/l or creatinine clearance < 50 ml/min or diabetes mellitus were randomly assigned to receive N-acetylcysteine 600 mg orally twice daily for two days or placebo. Only low osmolality ionic contrast medium was used.

RESULTS

Sixteen patients developed CIN, defined as an increase of 44.2 micromol/l in creatinine in 48 hours: eight of 77 patients (10.4%) in the N-acetylcysteine group and eight of 79 patients (10.1%) in the placebo group (p = 1.00). The mean (SD) change in serum creatinine was similar in both groups: 7.96 (35.36) micromol/l in the N-acetylcysteine group and 6.19 (25.64) micromol/l in the placebo group (p = 0.67). No difference was observed in the change in endogenous creatinine clearance (-0.54 (10.4) ml/min v -2.52 (12.3) ml/min, N-acetylcysteine and placebo, respectively, p = 0.28).

CONCLUSION

Oral N-acetylcysteine did not prevent CIN in patients at low to moderate risk undergoing cardiac catheterisation with ionic low osmolality contrast medium.

Intracoronary brachytherapy in the treatment of in-stent restenosis. Initial experience in Brazil

Intracoronary brachytherapy using beta or gamma radiation is currently the most efficient type of therapy for preventing the recurrence of coronary in-stent restenosis. Its implementation depends on the interaction among interventionists, radiotherapists, and physicists to assure the safety and quality of the method. The authors report the pioneering experience in Brazil of the treatment of 2 patients with coronary in-stent restenosis, in whom beta radiation was used as part of the international multicenter randomized PREVENT study (Proliferation REduction with Vascular ENergy Trial). The procedures were performed rapidly and did not require significant modifications in the traditional techniques used for conventional angioplasty. Alteration in the radiological protection devices of the hemodynamic laboratory were also not required, showing that intracoronary brachytherapy using beta radiation can be incorporated into the interventional tools of cardiology in our environment.

High versus low-pressure balloon inflation during multilinktrade mark stent implantation: acute and long-term angiographic results

We compared the impact of low and high-pressure balloon inflation on acute and late angiographic results of Multilink stent. Low-pressure balloon inflation (9.5 +/- 1.9 atm) was used in 43 stents and high pressure (17.1 +/- 1.5 atm) in 44. A larger immediate luminal gain was achieved in stents with high-pressure balloon inflation (1.80 +/- 0.26 vs. 1.47 +/- 0.62; P = 0.002), resulting in a larger mean diameter in this group (2.71 +/- 0.37 vs. 2.48 +/- 0.47; P = 0.017). At follow-up, a larger luminal diameter was achieved in the high pressure group (1.93 +/- 0.72 vs. 1.45 +/- 0.66; P = 0.002) and a trend to a lower rate of angiographic restenosis (15% vs. 38%, P = 0.08).

Single coronary arteries: two cases with distinct and previously undescribed angiographic patterns

Single coronary artery is a rare congenital anomaly, sometimes associated with myocardial ischemia. We present the clinical and angiographic features of two symptomatic patients with documented myocardial ischemia and with distinct and previously undescribed patterns of single right coronary arteries. These cases are new variants of the types R-I and R-II-A, in which the most probable mechanisms of ischemia are the insufficient blood supply, due to the long trajectories of the single arteries and the presence of underdeveloped vessels. Also, our second case presented with a fistulae from the LCX to the left ventricle, which is another determinant of myocardial ischemia.

Regression of ST segment elevation after thrombolysis in acute aortic dissection

A 55-year-old man was admitted to the hospital with chest pain and electrocardiogram consistent with the diagnosis of evolving myocardial infarction. Treatment with streptokinase was administered, resulting in clinical and electrocardiographic signs of reperfusion. Hypotension and ST segment elevation occurred 2 hours later and cardiac catheterization was done. At catheterization the diagnosis of aortic dissection was made, but the patient died before surgery. Thus, clinical and electrocardiographic signs of reperfusion after streptokinase may occur in patients with aortic dissection and myocardial infarction.

Chagas cardiomyopathy and captopril

Chagas disease is a leading cause of heart failure in Latin America. Sudden death occurs in approximately 40% of patients with heart failure due to Chagas disease. We report a single blind, cross-over trial of prolonged treatment with captopril and placebo in 18 Chagas disease patients with class IV NYHA heart failure. Ventricular dimensions, neurohormones, electrolytes and ventricular arrhythmias were analysed in 11 men and seven women receiving stable doses of digoxin and frusemide who were randomly divided into two intervention groups. Group I patients were given increasing doses of captopril up to 150 mg.day-1 maintained for 6 weeks, group II received the placebo. A 24 h Holter, 2-D echocardiogram, urinary catecholamines, plasma renin and electrolyte determinations were performed at the end of each phase. After a 2-week washout period, the two groups crossed over and another period of 6 weeks was observed. Ventricular arrhythmias were analysed by either Mann-Whitney or the Wilcoxon test. Remaining data were assessed by the Student t-test. A significant reduction in heart rate and urinary catecholamine levels, and enhanced plasma levels of renin, together with a reduction in ventricular couplets was found in the captopril-treated group. We conclude that captopril has a beneficial effect on neurohormones with a subsequently reduced heart rate and diminished incidence of ventricular arrhythmias in patients with Chagas disease. This effect might result in a reduction of mortality caused by the disease, suggesting the need for further investigations.

Exercise testing in the latent phase of Chagas' disease

Exercise stress testing was performed in 50 completely asymptomatic patients in the latent phase of Chagas' disease. In 32 (64%) abnormalities were found consisting of either abnormal ST depression, exercise-induced arrhythmias, or chronotropic incompetence. The latter was determined by comparing the heart rate response to 50 age- and sex-matched control patients without serologic evidence of Chagas' disease. In the absence of an adequate control population we can only speculate as to the significance of the ST depression and arrhythmias during exercise. However, chronotropic incompetence may be a specific marker for Trypanosomal infestation in an endemic area. It probably is an early manifestation of autonomic dysfunction secondary to Chagas' disease.