Endothelial, platelet, and macrophage microparticle levels do not change acutely following transcatheter aortic valve replacement

BACKGROUND

Patients with severe aortic stenosis have increased levels of prothrombotic and proinflammatory microparticles (MP), and MPs actively regulate pathological processes that lead to atherothrombotic cardiovascular events. Shear stress is a validated stimulus of MP production, and abnormal shear stress in aortic stenosis increases MP release in ex-vivo studies. We hypothesized that in patients with severe aortic stenosis, percutaneous replacement of the aortic valve (TAVR) would reduce abnormal shear stress and would decrease levels of circulating MPs.

FINDINGS

The experimental protocol utilized flow cytometry (FC) and nanoparticle tracking analysis (NTA) to quantify circulating plasma MP levels in aortic stenosis patients at baseline and 5 days after TAVR. The baseline and 5 day MP counts measured by FC were 6.10⋅10(5) ± 1.21⋅10(5) MP/μL and 5.74⋅10(5) ± 9.54⋅10(4) MP/μL, respectively (p = 0.91). The baseline and 5 day MP counts measured by NTA were 9.29⋅10(13) ± 1.66⋅10(13) MP/μL and 3.95⋅10(14) ± 3.11⋅10(14) MP/μL, respectively (p = 0.91). When MPs were stratified by cell source, there was no difference in pre/post TAVR endothelial, platelet, or leukocyte MP levels.

CONCLUSION

Levels of circulating MPs do not change acutely following TAVR therapy for aortic stenosis. Trial registered at clinicaltrials.gov NCT02193035 on July 11, 2014.

Heart Transplant in Patients with Predominantly Rheumatic Valvular Heart Disease

BACKGROUND AND AIM OF THE STUDY

International records indicate that only 2.6% of patients with heart transplants have valvular heart disease. The study aim was to evaluate the epidemiological and clinical profile of patients with valvular heart disease undergoing heart transplantation.

METHODS

Between 1985 and 2013, a total of 569 heart transplants was performed at the authors' institution. Twenty patients (13 men, seven women; mean age 39.5 +/- 15.2 years) underwent heart transplant due to structural (primary) valvular disease. Analyses were made of the patients' clinical profile, laboratory data, echocardiographic and histopathological data, and mortality and rejection.

RESULTS

Of the patients, 18 (90%) had a rheumatic etiology, with 85% having undergone previous valve surgery (45% had one or more operations), and 95% with a normal functioning valve prosthesis at the time of transplantation. Atrial fibrillation was present in seven patients (35%), while nine (45%) were in NYHA functional class IV and eight (40%) in class III. The indication for cardiac transplantation was refractory heart failure in seven patients (35%) and persistent NYHA class III/IV in ten (50%). The mean left ventricular ejection fraction (LVEF) was 26.6 +/- 7.9%. The one-year mortality was 20%. Histological examination of the recipients' hearts showed five (27.7%) to have reactivated rheumatic myocarditis without prior diagnosis at the time of transplantation. Univariate analysis showed that age, gender, LVEF, rheumatic activity and rejection were not associated with mortality at one year.

CONCLUSION

Among the present patient cohort, rheumatic heart disease was the leading cause of heart transplantation, and a significant proportion of these patients had reactivated myocarditis diagnosed in the histological analyses. Thus, it appears valid to investigate the existence of rheumatic activity, especially in valvular cardiomyopathy with severe systolic dysfunction before transplantation.

Performance of surgical risk scores to predict mortality after transcatheter aortic valve implantation

Background

Predicting mortality in patients undergoing transcatheter aortic valve implantation (TAVI) remains a challenge.

Objectives

To evaluate the performance of 5 risk scores for cardiac surgery in predicting the 30-day mortality among patients of the Brazilian Registry of TAVI.

Methods

The Brazilian Multicenter Registry prospectively enrolled 418 patients undergoing TAVI in 18 centers between 2008 and 2013. The 30-day mortality risk was calculated using the following surgical scores: the logistic EuroSCORE I (ESI), EuroSCORE II (ESII), Society of Thoracic Surgeons (STS) score, Ambler score (AS) and Guaragna score (GS). The performance of the risk scores was evaluated in terms of their calibration (Hosmer–Lemeshow test) and discrimination [area under the receiver–operating characteristic curve (AUC)].

Results

The mean age was 81.5 ± 7.7 years. The CoreValve (Medtronic) was used in 86.1% of the cohort, and the transfemoral approach was used in 96.2%. The observed 30-day mortality was 9.1%. The 30-day mortality predicted by the scores was as follows: ESI, 20.2 ± 13.8%; ESII, 6.5 ± 13.8%; STS score, 14.7 ± 4.4%; AS, 7.0 ± 3.8%; GS, 17.3 ± 10.8%. Using AUC, none of the tested scores could accurately predict the 30-day mortality. AUC for the scores was as follows: 0.58 [95% confidence interval (CI): 0.49 to 0.68, p = 0.09] for ESI; 0.54 (95% CI: 0.44 to 0.64, p = 0.42) for ESII; 0.57 (95% CI: 0.47 to 0.67, p = 0.16) for AS; 0.48 (95% IC: 0.38 to 0.57, p = 0.68) for STS score; and 0.52 (95% CI: 0.42 to 0.62, p = 0.64) for GS. The Hosmer–Lemeshow test indicated acceptable calibration for all scores (p > 0.05).

Conclusions

In this real world Brazilian registry, the surgical risk scores were inaccurate in predicting mortality after TAVI. Risk models specifically developed for TAVI are required.

Initial experience with Pomerantzeff's technique for reduction of the size of giant left atrium

INTRODUCTION

The most common indication for surgical correction of giant left atrium is associated with mitral valve insufficiency with or without atrial fibrillation. Several techniques for this purpose are already described with varying results.

OBJECTIVE

To present the initial experience with the tangential triangular resection technique (Pomerantzeff).

METHODS

From 2002 to 2010, four patients underwent mitral valve operation with reduction of left atrial volume by the technique of triangular resection tangential in our service. Three patients were female. The age ranged from 21 to 51 years old. The four patients presented with atrial fibrillation. Ejection fraction of left ventricle preoperatively ranged from 38% to 62%. The left atrial diameter ranged from 78mm to 140mm. After treatment of mitral dysfunction, the left atrium was reduced by resecting triangular tangential posterior wall between the pulmonary veins to avoid anatomic distortion of the mitral valve or pulmonary veins, reducing tension in the suture line.

RESULTS

Average hospital stay was 21.5 ± 6.5 days. The mean cardiopulmonary bypass time was 130 ± 30 minutes. There was no surgical bleeding or mortality in the postoperative period. All patients had sinus rhythm restored in the output of cardiopulmonary bypass, maintaining this rate postoperatively. The average diameter of the left atrium was reduced by 50.5% ± 19.5%. The left ventricular ejection fraction improved in all patients.

CONCLUSION

Initial results with this technique have shown effective reduction of the left atrium.

Natriuretic peptides and long-term mortality in patients with severe aortic stenosis

BACKGROUND AND AIM OF THE STUDY

The natriuretic peptides, brain natriuretic peptide (BNP) and its N-terminal prohormone (NT-proBNP), can be used as diagnostic and prognostic markers for aortic stenosis (AS). However, the association between BNP, NT-proBNP, and long-term clinical outcomes in patients with severe AS remains uncertain.

METHODS

A total of 64 patients with severe AS was prospectively enrolled into the study, and underwent clinical and echocardiographic assessments at baseline. Blood samples were drawn for plasma BNP and NT-proBNP analyses. The primary outcome was death from any cause, through a six-year follow up period. Cox proportional hazards modeling was used to examine the association between natriuretic peptides and long-term mortality, adjusting for important clinical factors.

RESULTS

During a mean period of 1,520 +/- 681 days, 51 patients (80%) were submitted to aortic valve replacement, and 13 patients (20%) were medically managed without surgical interventions. Mortality rates were 13.7% in the surgical group and 62% in the medically managed group (p < 0.001). Patients with higher plasma BNP (> 135 pg/ml) and NT-proBNP (> 1,150 pg/ml) levels at baseline had a greater risk of long-term mortality (hazard ratio [HR] 3.2, 95% confidence interval [CI] 1.1-9.1; HR 4.3, 95% CI 1.4-13.5, respectively). After adjusting for important covariates, both BNP and NT-proBNP remained independently associated with long-term mortality (HR 2.9, 95% CI 1.5-5.7; HR 1.8, 95% CI 1.1-3.1, respectively).

CONCLUSION

In patients with severe AS, plasma BNP and NT-proBNP levels were associated with long-term mortality. The use of these biomarkers to guide treatment might represent an interesting approach that deserves further evaluation.

Comparison of inhaled nitric oxide versus oxygen on hemodynamics in patients with mitral stenosis and severe pulmonary hypertension after mitral valve surgery

Pulmonary hypertension represents an important cause of morbidity and mortality in patients with mitral stenosis who undergo cardiac surgery, especially in the postoperative period. The aim of this study was to test the hypothesis that inhaled nitric oxide (iNO) would improve the hemodynamic effects and short-term clinical outcomes of patients with mitral stenosis and severe pulmonary hypertension who undergo cardiac surgery in a randomized, controlled study. Twenty-nine patients (4 men, 25 women; mean age 46 ± 2 years) were randomly allocated to receive iNO (n = 14) or oxygen (n = 15) for 48 hours immediately after surgery. Hemodynamic data, the use of vasoactive drugs, duration of stay, and short-term complications were assessed. No differences in baseline characteristics were observed between the groups. After 24 and 48 hours, patients receiving iNO had a significantly greater increase in cardiac index compared to patients receiving oxygen (p <0.0001). Pulmonary vascular resistance was also more significantly reduced in patients receiving iNO versus oxygen (-117 dyne/s/cm(5), 95% confidence interval -34 to -200, vs 40 dyne/s/cm(5), 95% confidence interval -34 to 100, p = 0.005) at 48 hours. Patients in the iNO group used fewer systemic vasoactive drugs (mean 2.1 ± 0.14 vs 2.6 ± 0.16, p = 0.046) and had a shorter intensive care unit stay (median 2 days, interquartile range 0.25, vs median 3 days, interquartile range 7, p = 0.02). In conclusion, iNO immediately after surgery in patients with mitral stenosis and severe pulmonary hypertension improves hemodynamics and may have short-term clinical benefits.

Validation of a new surgical risk score for heart valve surgery: VMCP

BACKGROUND

Some studies have developed scores for the assessment of surgical risk, particularly the EuroSCORE, which, however, is complex and difficult to apply. We suggest a new and simpler score, which is more appropriate for the clinical practice and for the assessment of surgical risk in patients with heart valve diseases.

OBJECTIVE

This study was conducted to create and validate a simple and practical score to predict mortality and morbidity related to heart valve surgery.

METHODS

Hospital data from 764 patients were collected, and the score was validated using two statistical models: death (= mortality) and length of hospital stay (LHS) > 10 days (= morbidity). The score was composed by four indexes (V [heart valve lesion], M [myocardial function], C [coronary artery disease], and P [pulmonary artery pressure]). A cut-off point was set for the score, and uni and multivariate analyses were performed to confirm whether the score would be able to predict mortality and morbidity. The existence of association with other risk factors was also studied.

RESULTS

The score was validated with good internal consistency (0.65), and the best cut-off point for mortality and morbidity was 8. Scores > 8 can predict LHS > 10 days (odds ratio [OR] = 1.7; p = 0.006) and a higher death risk, at least in the univariate analysis (p = 0.049). However, the death risk could not be predicted in the multivariate analysis (p=0.258).

CONCLUSION

VMCP scores > 8 can predict LHS > 10 days and may be used as a new tool for the follow-up of patients with heart valve disease undergoing surgery.

Contrast-enhanced magnetic resonance imaging identifies focal regions of intramyocardial fibrosis in patients with severe aortic valve disease: Correlation with quantitative histopathology

BACKGROUND

Chronic aortic valve disease (AVD) is characterized by progressive accumulation of interstitial myocardial fibrosis (MF). However, assessment of MF accumulation has only been possible through histologic analyses of endomyocardial biopsies. We sought to evaluate contrast-enhanced magnetic resonance imaging (ce-MRI) as a noninvasive method to identify the presence of increased MF in patients with severe AVD.

METHODS

Seventy patients scheduled to undergo aortic valve replacement surgery were examined by cine and ce-MRI in a 1.5-T scanner. Cine images were used for the assessment of left ventricular (LV) volumes, mass, and function. Delayed-enhancement images were used to characterize the regions of MF. In addition, histologic analyses of myocardial samples obtained during aortic valve replacement surgery were used for direct quantification of interstitial MF. Ten additional subjects who died of noncardiac causes served as controls for the quantitative histologic analyses.

RESULTS

Interstitial MF determined by histopathologic analysis was higher in patients with AVD than in controls (2.7% +/- 2.0% vs 0.6% +/- 0.2%, P = .001). When compared with histopathologic results, ce-MRI demonstrated a sensitivity of 74%, a specificity of 81%, and an accuracy of 76% to identify AVD patients with increased interstitial MF. There was a significant inverse correlation between interstitial MF and LV ejection fraction (r = -0.67, P < .0001). Accordingly, patients with identifiable focal regions of MF by ce-MRI exhibited worse LV systolic function than those without MF (45% +/- 14% vs 65% +/- 14%, P < .0001).

CONCLUSIONS

Contrast-enhanced MRI allows for the noninvasive detection of focal regions of MF in patients with severe AVD. Moreover, patients with identifiable MF by ce-MRI exhibited worse LV functional parameters.

Effects of carvedilol treatment in dogs with chronic mitral valvular disease

BACKGROUND

Stimulation of the sympathetic nervous system occurs during the development of heart failure in dogs with chronic mitral valvular disease (CMVD).

HYPOTHESIS

The use of beta-blockers to modulate the activation of the sympathetic nervous system would be useful in dogs with CMVD.

ANIMALS

Group A included 13 dogs who received the conventional treatment (digoxin, benazepril, a reduced sodium diet, and codeine, and a diuretic when indicated), and group B included 12 dogs who received the protocol above plus carvedilol (0.3 mg/kg q12h).

METHODS

Blinded, placebo, controlled study.

RESULTS

The main echodopplercardiographic variables, heart rate, biochemical data, functional classification (FC) (New York Heart Association) and quality of life score (functional evaluation of cardiac health questionnaire) were assessed at baseline (TO) and after 3 months (T1). Only group B showed improvement in score of quality of life (13.8 +/- 8.8 versus 6.0 +/- 6.3; P < .001), in FC (2.4 - 0.9 versus 1.8 +/- 0.7; P = .032) and a reduction in systolic blood pressure (151.2 +/- 18.3 versus 124.5 +/- 23.4; P = .021). Two deaths from group A and 1 from B were related to CMVD.

CONCLUSION

The studied dose of carvedilol in this group did not improve the sympathetic activation and echocardiographic variables over 3 months of chronic oral treatment. However, the results suggested a beneficial effect on the quality of life score, functional classification, and a reduction on systolic blood pressure.