Prospective validation of the prognostic usefulness of B-type natriuretic peptide in asymptomatic patients with chronic severe aortic regurgitation

The Impact of Aortic Valve Replacement on Left Ventricular Remodeling in Children

There are scant data in pediatrics on the optimal timing for aortic valve repair (AVR). This study assesses the midterm response to AVR and possible predictors of poor outcome. From 2001 to 2006, 41 patients had greater than 3-month follow-up after AVR for aortic insufficiency, aortic stenosis, or both. Pre-, peri-, and post-operative data were collected, including demographics and clinical symptoms. Two reviewers measured echocardiographic parameters from the pre-operative and latest follow-up echocardiograms. Ventricular dimensions were indexed to body surface area (z-score). Median age at AVR was 13 years with 83 % having a Ross operation. The average left ventricular end-diastolic dimension pre-op, z-score of +1.3, significantly decreased at last follow-up to a mean z-score of -0.1 (p < 0.001). Similarly the indexed LV mass decreased from +3.9 to +0.5 (p < 0.001). There was no significant correlation between the presence of pre-op symptoms and the presence of post-op LV dilatation, hypertrophy, or dysfunction. In the subset of patients (7/41) with persistent LV dysfunction at last follow-up, there was a significant correlation with pre-op LV dilatation as assessed by both LVEDD (p = 0.02) and LVESD (p = 0.05). Children demonstrate significant reverse remodeling after AVR. Pre-op LV dilatation may predict patients with persistent LV dysfunction post-AVR. Symptoms are less useful in children, suggesting the need for more objective data for functional assessment.

Synergistic Utility of Brain Natriuretic Peptide and Left Ventricular Global Longitudinal Strain in Asymptomatic Patients With Significant Primary Mitral Regurgitation and Preserved Systolic Function Undergoing Mitral Valve Surgery

Background—

In asymptomatic patients with ≥3+ mitral regurgitation and preserved left ventricular (LV) ejection fraction who underwent mitral valve surgery, we sought to discover whether baseline LV global longitudinal strain (LV-GLS) and brain natriuretic peptide provided incremental prognostic utility.

Methods and Results—

Four hundred and forty-eight asymptomatic patients (61±12 years and 69% men) with ≥3+ primary mitral regurgitation and preserved left ventricular ejection fraction, who underwent mitral valve surgery (92% repair) at our center between 2005 and 2008, were studied. Baseline clinical and echocardiographic data (including LV-GLS using Velocity Vector Imaging, Siemens, PA) were recorded. The Society of Thoracic Surgeons score was calculated. The primary outcome was death. Mean Society of Thoracic Surgeons score, left ventricular ejection fraction, mitral effective regurgitant orifice, indexed LV end-diastolic volume, and right ventricular systolic pressure were 4±1%, 62±3%, 0.55±0.2 cm 2 , 58±13 cc/m 2 , and 37±15 mm Hg, respectively. Forty-five percent of patients had flail. Median log-transformed BNP and LV-GLS were 4.04 (absolute brain natriuretic peptide: 60 pg/dL) and −20.7%. At 7.7±2 years, death occurred in 41 patients (9%; 0% at 30 days). On Cox analysis, a higher Society of Thoracic Surgeons score (hazard ratio 1.55), higher baseline right ventricular systolic pressure (hazard ratio 1.11), more abnormal LV-GLS (hazard ratio 1.17), and higher median log-transformed BNP (hazard ratio 2.26) were associated with worse longer-term survival (all P <0.01). Addition of LV-GLS and median log-transformed BNP to a clinical model (Society of Thoracic Surgeons score and baseline right ventricular systolic pressure) provided incremental prognostic utility (χ 2 for longer-term mortality increased from 31–47 to 61; P <0.001).

Conclusions—

In asymptomatic patients with significant primary mitral regurgitation and preserved left ventricular ejection fraction who underwent mitral valve surgery, brain natriuretic peptide and LV-GLS provided synergistic risk stratification, independent of established factors.

Outcome of paravalvular leak repair after transcatheter aortic valve replacement with a balloon-expandable prosthesis

BACKGROUND

Significant paravalvular leak (PVL) occurs in up to 13% of patients after transcatheter aortic valve replacement (TAVR) with a balloon-expandable bioprosthesis. Transcatheter PVL repair has emerged as a less invasive alternative for this problem.

OBJECTIVES

The aim of this study was to evaluate the safety, feasibility, and clinical outcomes of transcatheter PVL repair after TAVR with balloon-expandable valve.

METHODS

We retrospectively identified 15 patients who underwent 16 PVL repair procedures after the TAVR at our center. Procedural characteristics, results, and clinical outcomes were analyzed. The association of PVL repairs with subsequent hospitalizations and mortality was assessed and compared to 57 patients who did not undergo repair for at least moderate PVL after TAVR.

RESULTS

The PVL repair was successful in 13 (87%) patients, without significant procedure or device related complications. In patients with successful PVL repair, there was an improvement in symptom status, subsequent hospitalizations, and B-type natriuretic peptide levels. There was 1 (out of 13, 8%) death in the group of patients who successfully underwent PVL repair whereas 24 (out of 57, 42%) patients died during follow up in the group that did not undergo repair of their PVL. Similarly, there was significant reduction in the subsequent heart failure related hospitalization after the PVL repair, compared with the patients who did not undergo PVL repair (P = 0.03).

CONCLUSION

Transcatheter repair of PVL after TAVR can be safely and effectively accomplished in carefully selected patients, and may lead to reduction in hospitalizations, improvement in symptoms, and long-term survival. © 2016 Wiley Periodicals, Inc.

Serum Brain Natriuretic Peptide Concentration 60 Days After Surgery as a Predictor of Long-Term Prognosis in Patients Implanted With a Left Ventricular Assist Device

Mechanical circulatory support by a left ventricular assist device (LVAD) is used to bridge patients with advanced heart failure to transplant or as a definitive treatment. We retrospectively sought predictors of long-term outcome in a cohort of 83 patients who had undergone LVAD treatment. We subjected perioperative clinical data of patients to statistical analysis to establish parameters associated with all-cause mortality, and the cutoff values, sensitivity, and specificity of those that had a statistically significant relation with survival. Mean follow-up was 717 days (standard deviation, 334 days; range, 17-1,592 days). Fourteen patients (16.8%) died, but nine (10.8%) were weaned from support. Serum brain natriuretic peptide (BNP) concentration measured 60 days after implantation was significantly associated with all-cause mortality. The optimal BNP cutoff value to predict death during LVAD support was 322 pg/ml, with a sensitivity of 71.4% and specificity of 79.8%. Two-year survival was 92.0% in those with 60 days serum BNP concentration <322 pg/ml compared with 70.5% in those in whom it was ≥322 pg/ml (p = 0.003). The relation between BNP and survival likely reflects recovery of native myocardial function and improvements in global health and should assist clinicians in the on-going management of long-term LVAD therapy.

Management strategies and future challenges for aortic valve disease

The management of aortic valve disease has been improved by accurate diagnosis and assessment of severity by echocardiography and advanced imaging techniques, efforts to elicit symptoms or objective markers of disease severity and progression, and consideration of optimum timing of aortic valve replacement, even in elderly patients. Prevalence of calcific aortic stenosis is growing in ageing populations. Conventional surgery remains the most appropriate option for most patients who require aortic valve replacement, but the transcatheter approach is established for high-risk patients or poor candidates for surgery. The rapid growth of transcatheter aortic valve replacement has been fuelled by improved technology, evidence-based clinical research, and setting up of multidisciplinary heart teams. Aortic regurgitation can be difficult to diagnose and quantify. Left ventricular dysfunction often precedes symptoms, needing active surveillance by echocardiography to determine the optimum time for aortic valve replacement. Development of transcatheter approaches for aortic regurgitation is challenging, owing to the absence of valvular calcification and distortion of aortic root anatomy in many patients.

Prognostic Utility of Brain Natriuretic Peptide in Asymptomatic Patients With Significant Mitral Regurgitation and Preserved Left Ventricular Ejection Fraction

We sought to study the prognostic utility of serum brain natriuretic peptide (BNP) in patients with significant primary mitral regurgitation (MR) and preserved left ventricular (LV) ejection fraction (EF). Consecutive 548 asymptomatic patients (age 62 ± 13 years and 66% men) with ≥ 3 + primary MR and preserved LVEF on echo at rest, evaluated at our center from 2005 to 2008 were studied. Baseline clinical and echo data were recorded and the Society of Thoracic Surgeons (STS) score was calculated. Mean STS score was 4 ± 1%. Mean LVEF, mitral effective regurgitant orifice, indexed LV end-systolic diameter, and right ventricular systolic pressure (RVSP) were 62 ± 4%, 0.55 ± 0.3 cm(2), 1.6 ± 0.3 cm/m(2), and 38 ± 15 mm Hg; 43% had flail. Median log-transformed brain natriuretic peptide (lnBNP) was 4.1 (interquartile range 3.30 to 5.0), corresponding to an absolute BNP value of 60 pg/ml (only 13% had an absolute BNP value >250 pg/ml). At 7.4 ± 2 years, 493 patients (90%) had mitral surgery (92% repair) and nonmalignancy death occurred in 53 patients (10%). On multivariate Cox analysis, higher STS score (hazard ratio [HR] 1.50, 95% CI 1.20 to 1.88), higher baseline RVSP (HR 1.17, 95% CI 1.02 to 1.35), and higher ln BNP (HR 2.51, 95% CI 1.86 to 3.39) predicted death, whereas mitral surgery (HR 0.17, 95% CI 0.09 to 0.30) was associated with improved survival (all p <0.01). Eighty-nine percent of deaths occurred in patients with lnBNP >4.1. Addition of lnBNP to a model of STS score, baseline RVSP, and mitral surgery provided incremental prognostic utility (chi-square for mortality increased from 137 to 162, p <0.001). In conclusion, in asymptomatic patients with ≥ 3 + primary MR and preserved LVEF, the addition of BNP improved risk stratification and higher BNP independently predicted reduced survival.

Timing of Dynamic NT-proBNP and hs-cTnT Response to Exercise Challenge in Asymptomatic Children with Moderate Aortic Valve Regurgitation or Moderate Aortic Valve Stenosis

Patients with congenital aortic valve stenosis (AVS) can remain asymptomatic but may develop progressive and often underestimated exercise intolerance. The risk of increased left ventricular (LV) wall stress, irreversible myocardial fibrosis and sudden death in untreated patients warrants earlier intervention. The timing for curative therapy for severe AVS is clear, but optimal timing for moderate stenosis (modAS) is unknown. AVS often coexists with aortic regurgitation, which adds a volume overload to an already pressure-overloaded LV, adding an additional challenge to the estimation of disease severity. We investigated the possible value of N-terminal pro-brain natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (hs-cTnT) upon treadmill exercise challenge in children with asymptomatic modAS versus moderate regurgitation (modAR). The aim was to determine optimal timing of peak biochemical response. Blood samples were obtained at rest, and then at 20, 40 and 60 min after peak exercise comparing modAS and modAR to healthy controls. Exercise performance was equivalent in all groups, with no difference for biomarker levels at rest. The increase in NT-proBNP was significant in modAR at 40 min (99.2 ± 48.6 ng/L; p = 0.04) and 60 min into recovery (100.0 ± 53.7 ng/L; p = 0.01), but not in modAS. The increase in hs-cTnT was significant only at 60 min into recovery for modAS and modAR. NT-proBNP and hs-cTnT following exercise challenge are possible discriminant biomarkers of modAR from modAS and controls at 60 min into recovery despite comparable exercise performance. This offers a promising avenue for future stratification of aortic valve disease and optimal timing of intervention.

Clinical Applications of Natriuretic Peptides in Assessment of Valvular Heart Disease

Biomarkers such as natriuretic peptides (NPs) have evolving clinical utility beyond the scope of heart failure. The role of NPs in the management of valvular heart disease is a growing area of investigation. NPs have much potential in the assessment of asymptomatic patients with hemodynamically significant valvular lesions who have traditionally been excluded from consideration of surgical intervention. NPs also have a role in the risk stratification of these patients as well as in routine surveillance and monitoring. Together with echocardiographic data and functional status, NPs are being incorporated into the management of valvular heart disease. In this review we examine the evidence for the role of natriuretic peptides in assessment of VHD.

Biomarkers in Cardiology - Part 2: In Coronary Heart Disease, Valve Disease and Special Situations

Cardiovascular diseases are the main causes of mortality and morbidity in Brazil. Their primary and secondary preventions are a priority for the health system and require multiple approaches for increased effectiveness. Biomarkers are tools used to identify with greater accuracy high-risk individuals, establish a faster diagnosis, guide treatment, and determine prognosis. This review aims to highlight the importance of biomarkers in clinical cardiology practice and raise relevant points regarding their application and perspectives for the next few years. This document was divided into two parts. This second part addresses the application of biomarkers in coronary heart disease, valvular diseases, cardio-oncology, pulmonary embolism, and cardiorenal syndrome.

Usefulness of serial B-type natriuretic peptide assessment in asymptomatic aortic stenosis

B-type natriuretic peptide (BNP) level may be a useful prognostic marker for the management of asymptomatic patients with aortic stenosis (AS). The aim of this study was to identify the echocardiographic determinants of BNP changes during follow-up in AS. We studied 61 asymptomatic patients with greater than moderate AS and preserved left ventricular (LV) ejection fraction who underwent rest and exercise Doppler echocardiography with concomitant BNP level measurement at baseline. BNP measurement was repeated after inclusion every 6 months. Patients were divided into 2 groups according to the median of BNP changes during follow-up. According to parameters at rest, patients in the high BNP changes group had significantly higher E/e' ratio. Statistically significant correlations were found between BNP changes and E/e' ratio and indexed left atrial area. According to exercise parameters, patients in the high BNP changes group had significantly lower exercise-induced increase in LV ejection fraction. Statistically significant correlations were found between BNP changes and exercise-induced changes in LV ejection fraction. After adjustment for age, mean aortic pressure gradient, and BNP level at baseline, multivariate analysis identified indexed left atrial area, E/e' at rest, and exercise-induced increase in ejection fraction as independent determinants of BNP changes during follow-up. In conclusion, this study shows that, in asymptomatic patients with preserved LV function and moderate AS, serial BNP measurements may widely vary. Subclinical LV diastolic and systolic dysfunctions are frequently present in patients with higher serial BNP changes.

Valvular heart disease: classic teaching and emerging paradigms

Valvular heart disease is both prevalent and increases with age. The final pathway of valvular disease is heart failure and sometimes sudden death, so clinicians must identify and treat it before these endpoints occur. Noninvasive diagnostic modalities such as echocardiography, exercise tolerance testing, and cardiac magnetic resonance provide additional quantitative, qualitative, and prognostic data. Studies have elucidated predictors of disease progression and potential medical therapies, but the niche of valvular disease has benefited relatively less from randomized controlled clinical trials than other cardiovascular disease fields. New invasive techniques like transcatheter valve replacement offer hope for high-risk operative candidates. We review classic teaching with current guidelines and emphasize recent advances in disease management.

Usefulness of serum brain natriuretic peptide to predict adverse events in patients with the Eisenmenger syndrome

The aim of this study was to evaluate the prognostic value of brain natriuretic peptide (BNP) in outpatients with the Eisenmenger syndrome (ES). BNP is often elevated in patients with cyanotic congenital heart disease. The clinical utility of BNP in patients with cyanotic congenital heart disease and the ES has not been clearly delineated. Records of adults with ES who had undergone serum BNP measurement were reviewed. The primary end point was death or heart failure admission. Fifty-three patients were included, with 15 patients (28%) meeting the primary end point (death in 7, heart failure hospitalization in 8). Mean and median baseline BNP in patients meeting the primary end point were 322 ± 346 and 179 pg/ml, compared to 100 ± 157 and 41 pg/ml in those not meeting the primary end point (p = 0.0029). A Cox proportional-hazards model using baseline BNP between the 2 groups yielded a hazard ratio of 1.84 (95% confidence interval [CI] 1.19 to 2.85, p = 0.006). The relative risk for baseline BNP level >140 pg/ml was 4.62 (95% CI 1.80 to 11.3, p = 0.008). Patients who met the primary end point increased their BNP levels by 42.5 pg/ml per year (95% CI 12.09 to 72.95, p = 0.006) compared to 7.2 pg/ml per year (95% CI 2.01 to 12.47, p = 0.007) in patients who did not meet the primary end point. In conclusion, elevated BNP levels are predictive of death or heart failure admission in patients with the ES. A serum BNP level >140 pg/ml is a useful tool in identifying high-risk patients.

Contemporary reviews by surgeon: timing of operation for chronic aortic regurgitation

The timing of operation for severe chronic and asymptomatic aortic regurgitation remains problematic, though the present trend is to prefer early surgery. In this article, we review recent reports, mainly published after 2006, regarding indications for surgical treatment for pure chronic AR.

Prognostic value of B-type natriuretic peptide in patients with chronic mitral regurgitation undergoing surgery: mid-term follow-up results

OBJECTIVES

The prognostic value of B-type natriuretic peptide (BNP) for surgical outcome in patients with mitral regurgitation (MR) has not been studied. The purpose of this study was to determine the prognostic value of BNP in patients with chronic severe MR, undergoing mitral valve surgery.

METHODS

In total, 117 patients with chronic severe MR undergoing surgery were evaluated from the MR registry of Seoul National University Hospital. Patients were excluded if they had acute MR or acutely decompensated heart failure, and significant renal, pulmonary, coronary or other significant valvular heart disease. The plasma BNP level assay and echocardiographic studies were done before surgery. Study endpoint was a composite of cardiac death and cardiac hospitalization during follow-up.

RESULTS

The median duration of the follow-up was 4.5 years, and the study endpoint was reached in 11 (9.4%) patients. Receiver-operating characteristic curve analysis yielded an optimal cut-off point of 125 pg/ml for BNP that distinguished patients with poor prognosis. Kaplan-Meier survival analysis with the log-rank test and multivariate Cox proportional hazards model showed that patients with BNP ≥125 pg/ml had a worse clinical outcome after surgery (log rank 7.606, P = 0.006; adjusted hazard ratio = 5.536 [95% confidence interval 1.189-25.788], P = 0.029).

CONCLUSIONS

Among patients with chronic severe MR undergoing mitral valve surgery, BNP independently predicts the poor clinical outcome. The BNP measurement should be considered in the risk stratification of these patients.

Effect of electrical stimulus parameters on the development and propagation of action potentials in short excitable fibres

Intracellular action potentials (IAPs) produced by short fibres in response to their electrical stimulation were analysed. IAPs were calculated on the basis of the Hodgkin-Huxley (1952) model by the method described by Joyner et al. (1978). Principal differences were found in processes of activation of short (semilength L less than 5 lambda) and long fibres under near-threshold stimulation. The shorter the fibre, the lower was the threshold value (Ithr). Dependence of the latency on the stimulus strength (Ist) was substantially non-linear and was affected by the fibre length. Both fibre length and stimulus strength influenced the IAP amplitude, the instantaneous propagation velocity (IPV) and the site of the first origin of the IAP (and, consequently, excitability of the short fibre membrane). With L less than or equal to 2 lambda and Ithr less than or equal to Ist less than or equal to 1.1Ithr, IPV could reach either very high values (so that all the fibre membrane fired practically simultaneously) or even negative values. The latter corresponded to the first origin of the propagated IAP, not at the site of stimulation but at the fibre termination or at a midpoint. The characters of all the above dependencies were unchanged irrespective of the manner of approaching threshold (variation of stimulus duration or its strength). Reasons for differences in processes of activation of short and long fibres are discussed in terms of electrical load and latency. Applications of the results to explain an increased jitter, velocity recovery function and velocity-diameter relationship are also discussed.