Systematic review of the outcome of aortic valve replacement in patients with aortic stenosis

Hemodynamic Factors Driving Peripheral Chemoreceptor Hypersensitivity: Is Severe Aortic Stenosis Treated with Transcatheter Aortic Valve Implantation a Valuable Human Model?

Background: A reduction in carotid artery blood flow (CABF) and ultimately in wall shear stress (WSS) is a major driver of heightened peripheral chemoreceptor (PCh) activity in animal models of heart failure. However, it is yet to be translated to humans. To provide more insight into this matter, we considered severe aortic stenosis (AS) before and after transcatheter aortic valve implantation (TAVI) as a human model of carotid and aortic body function under dramatically different hemodynamic conditions. Materials and Methods: A total of 26 severe AS patients (aged 77 ± 6 y, body mass index: 29.1 ± 5.1 kg/m2, left ventricular ejection fraction (LVEF): 50 ± 15%) were subjected to a transient hypoxia test twice: immediately before vs. 1-4 months after TAVI (median follow-up: 95 days). PCh function was analyzed in terms of ventilatory (HVR, L/min/SpO2%) and heart rate responses to hypoxia (HR slope, bpm/SpO2%). Standard ultrasound (inc. aortic valve area [AVA], mean aortic valve gradient, peak aortic jet velocity, LVEF, and CABF), respiratory, hemodynamic, and blood parameters were collected at both visits. Pre- vs. post-TAVI data regarding HVR and HR slopes were available for N = 26 and N = 10 patients, respectively. Results: HVR did not change following TAVI (pre- vs. post-TAVI: 0.42 ± 0.29 vs. 0.39 ± 0.33 L/min/SpO2%, p = 0.523). The HR slope increased after TAVI (pre- vs. post-TAVI: 0.26 ± 0.23 vs. 0.37 ± 0.30 bpm/SpO2%, p = 0.019), and the magnitude of the increase was strongly associated with an increase in AVA (Spearman's R = 0.80, p = 0.006). No other significant relations between pre- vs. post-TAVI changes in PCh activity measures vs. hemodynamic parameters were found (all p > 0.12). Conclusions: The ventilatory component of the PCh reflex (defined as HVR) in severe AS patients is not affected by TAVI, and pre-TAVI values in this group are fairly comparable to those reported previously for healthy subjects. On the contrary, HR responses to hypoxia are increased after TAVI, and pre-TAVI values appear to be lower compared to the healthy population. An extraordinarily strong correlation between post-TAVI increases in HR slope and AVA may suggest that hemodynamic repercussions of the surgery in the aortic body area (most likely reduced WSS) play a critical role in determining aortic body function with a negligible effect on the carotid bodies. However, caution is needed when interpreting the results of the HR response to hypoxia in our study due to the small sample size (N = 10).

Systolic blood pressure response during exercise testing in symptomatic severe aortic stenosis

AIMS

Exercise testing remains underused in patients with aortic stenosis (AS), partly due to concerns about an exercise-induced drop in systolic blood pressure (SBP). We aimed to study the SBP response to exercise in patients with severe symptomatic AS prior to surgery and 1 year postoperatively.

METHODS

Patients scheduled for aortic valve replacement due to severe symptomatic AS were enrolled at a single centre in a prospective observational cohort study. Maximal cardiopulmonary exercise testing (CPET) was performed on a cycle ergometer at baseline and 1 year postoperatively, using standard termination criteria. The SBP response was categorised according to the last measurements of SBP during exercise, in relation to workload (the SBP/watt-slope) as 'normal' (>0.25 mm Hg/watt), 'flat' (0-0.25 mm Hg/watt) or 'drop' (<0 mm Hg/watt).

RESULTS

45 patients (28 male, 66±9 years, left ventricular ejection fraction 59%±5%, aortic jet velocity 4.6±0.5 m/s) were included, with pairwise comparison available in 31 cases. There were no adverse events. Preoperatively, 4/45 patients were categorised as 'drop', 23 as 'flat' and 18 as 'normal'. There was a change in the distribution of categories from preoperative to postoperative measurements (43% 'normal' vs 74% 'normal', p=0.0046). Maximal SBP and workload-indexed SBP were higher postoperatively than preoperatively (203±26 vs 182±28 mm Hg, p<0.001 and 0.43±0.14 vs 0.29±0.15 mm Hg/watt, p<0.001).

CONCLUSION

As a drop in SBP was infrequent (<10%) in patients with severe symptomatic AS and no adverse events occurred, our results indicate that CPET may be performed under careful monitoring in AS patients. Postoperatively, the SBP reaction improved, with no patient having a drop in SBP.

TRIAL REGISTRATION NUMBER

NCT02790008.

Left Ventricular Reverse Remodeling after Surgical Aortic Valve Replacement for Aortic Regurgitation-An Explorative Study

BACKGROUND

The timing of treatment for chronic aortic valve regurgitation (AR), especially in asymptomatic patients, is gaining attention since less invasive strategies have become available. The aim of the present study was to evaluate left ventricular reverse remodeling after aortic valve replacement (AVR) for severe AR.

METHODS

Patients (n = 25) who underwent surgical AVR for severe AR with left ventricular ejection fraction (LVEF) less than 55% were included in this study. Preprocedural and follow-up clinical and echocardiographic measurements of LVEF and left ventricular (LV) diameters were retrospectively analyzed.

RESULTS

Mean LVEF increased significantly following surgical AVR (p < 0.0001). LV diameters showed a clear regression (p = 0.0088). Younger patients and those receiving a mechanical valve tended to have less improved LVEF on follow-up than patients over 60 years or the ones who were implanted with a biological prosthesis (p = 0.0239 and p = 0.069, respectively). Gender had no effect on the degree of LVEF improvement (p = 0.4908).

CONCLUSIONS

We demonstrated significant LV reverse remodeling following AVR for AR. However, more data are needed on LV functional and geometrical improvement comparing the different types of valve prostheses to provide an optimal treatment strategy.

Mechanisms of myocardial reverse remodelling and its clinical significance: A scientific statement of the ESC Working Group on Myocardial Function

Cardiovascular disease (CVD) is the leading cause of morbimortality in Europe and worldwide. CVD imposes a heterogeneous spectrum of cardiac remodelling, depending on the insult nature, that is, pressure or volume overload, ischaemia, arrhythmias, infection, pathogenic gene variant, or cardiotoxicity. Moreover, the progression of CVD-induced remodelling is influenced by sex, age, genetic background and comorbidities, impacting patients' outcomes and prognosis. Cardiac reverse remodelling (RR) is defined as any normative improvement in cardiac geometry and function, driven by therapeutic interventions and rarely occurring spontaneously. While RR is the outcome desired for most CVD treatments, they often only slow/halt its progression or modify risk factors, calling for novel and more timely RR approaches. Interventions triggering RR depend on the myocardial insult and include drugs (renin-angiotensin-aldosterone system inhibitors, beta-blockers, diuretics and sodium-glucose cotransporter 2 inhibitors), devices (cardiac resynchronization therapy, ventricular assist devices), surgeries (valve replacement, coronary artery bypass graft), or physiological responses (deconditioning, postpartum). Subsequently, cardiac RR is inferred from the degree of normalization of left ventricular mass, ejection fraction and end-diastolic/end-systolic volumes, whose extent often correlates with patients' prognosis. However, strategies aimed at achieving sustained cardiac improvement, predictive models assessing the extent of RR, or even clinical endpoints that allow for distinguishing complete from incomplete RR or adverse remodelling objectively, remain limited and controversial. This scientific statement aims to define RR, clarify its underlying (patho)physiologic mechanisms and address (non)pharmacological options and promising strategies to promote RR, focusing on the left heart. We highlight the predictors of the extent of RR and review the prognostic significance/impact of incomplete RR/adverse remodelling. Lastly, we present an overview of RR animal models and potential future strategies under pre-clinical evaluation.

Approach to the patient with decompensated cirrhosis and aortic stenosis during liver transplantation evaluation

Aortic stenosis (AS) is the most common valvular disease and is reported to be present in 2%-7% of people over the age of 65. Risk factors for aortic stenosis and NASH overlap; thus, as the population ages, there is an increased likelihood that patients undergoing liver transplantation evaluation may have severe aortic stenosis. There is a high mortality rate associated with cardiac surgeries in patients with cirrhosis. Further, there are no guidelines that assist in the decision making process for patients with cirrhosis and AS. In this review, we highlight key studies that compare transcatheter aortic valve implantation (TAVI) with surgical aortic valve replacement (SAVR) in patients with cirrhosis. We propose an algorithm as to how to approach the patient with aortic stenosis and considerations unique to patients with cirrhosis (i.e., anticoagulation, EGD for variceal assessment; need to determine timing after TAVI before listing).

Reverse remodelling after aortic valve replacement for chronic aortic regurgitation

OBJECTIVES

This study aimed to assess the long-term outcomes and investigate the factors related to left ventricular (LV) reverse remodelling after aortic valve replacement (AVR) in patients with chronic aortic regurgitation (AR).

METHODS

A total of 246 patients who underwent AVR for chronic AR at our institution were included in this retrospective study. Primary end-points included all-cause mortality, cardiac mortality and major adverse cerebral and cardiovascular events. Secondary end-points included cardiac function on echocardiography 1 year after surgery. We explored the predictive factors for reverse remodelling 1 year after surgery.

RESULTS

The 10-year survival rate was 86.0%, with no cardiac deaths in 93.8% and no major adverse cerebral and cardiovascular events in 79.9% of patients. Postoperative LV function and symptoms were significantly improved 1 year after surgery, but 34 patients (13.8%) did not recover normal function and structure. A significant negative correlation was found between the incidence of cardiac death and major adverse cerebral and cardiovascular events and reverse remodelling. Multivariate logistic regression identified preoperative LV ejection fraction (P = 0.001, odds ratio = 1.057) and LV end-systolic dimension index (P = 0.038, odds ratio = 0.912) as significant predictive factors of reverse remodelling 1 year after surgery.

CONCLUSIONS

Preoperative LV ejection fraction and LV end-systolic dimension index were predictive factors for reverse remodelling after surgery, which was associated with late outcomes. Earlier surgery may thus help to restore normal LV function and achieve better late outcomes after AVR for AR.

Surgical Aortic Valve Replacement in the Elderly: It Is Worth It!

To evaluate survival and quality of life of octogenarians after surgical aortic valve replacement (SAVR), up to 10 year of follow-up. Retrospective observational study on octogenarians operated for an isolated or combined SAVR in 2 centers between 2005 and 2011. Preoperative data were collected for each patient and updated regularly with last follow-up on July 2018. Early postoperative course was assessed for all patients. The primary outcome was late survival after discharge. Health-related quality of life was evaluated in all surviving patients using the Short-Form 12 questionnaire. Nine hundred and nine patients were included. The median age was 82 ± 2.6 years, with 400/909 females (44%). Isolated AVR was performed in 452/909 patients (49.7%). Early in-hospital mortality occurred in 71/909 patients (7.8%). Mean follow-up was 5.9 ± 3.4 years. Survival at 2, 5, and 10 years in the overall cohort was 89%, 70%, and 28%, respectively, without significant difference between isolated or combined AVR. Survival was significantly higher in patients with a Euroscore <8% (P< 0.0001). Multivariate analysis found that older age at surgery, diabetes, history of myocardial infarction, atrial fibrillation and chronic renal failure were predictors of long-term mortality. Finally, the SF-12 physical score was 40.7 ± 10.4 and mental and emotional score was 52.7 ± 8.6 at last follow-up, which falls within the expected range for the general population (50 ± 10) with comparable age. SAVR remains an effective treatment for aortic valve disease in octogenarians, not only increasing life expectancy but also conferring a long-standing quality of life with excellent valve durability.

Evaluation of β-blocker therapy for long-term outcomes in patients with low ejection fraction after cardiac surgery

Background

Preoperative low left ventricular ejection fraction (LVEF) has been reported as an independent risk factor for in-hospital mortality. However, there were few studies evaluating the long-term mortality in these patients. We, therefore, conducted this study to investigate long-term outcomes of surgery on patients with LVEF≤35% undergoing a broad range of cardiac procedures.

Methods

We performed a retrospective cohort study in 510 patients from January 1, 2007 to September 1, 2019. These patients were divided into survival group (n = 386) and non-survival group (n = 124). The multivariate Cox analysis was used to estimate the risk factors for survival. In Cox analysis, β-blockers were indicated to be associated with long-term mortality. To further address bias, we derived a propensity score predicting the function of β-blockers on survival, and matched 52 cases to 52 controls with similar risk profiles.

Results

Patients were followed for a median period of 24 months (interquartile range: 11–44 months). Multivariate Cox regression analysis indicated that the non-survival group had higher weight, higher EuroSCORE, more smoking patients, longer time of cardiopulmonary bypass (CPB), more intra-aortic balloon pump (IABP) use, and more patients who always used β-blocker (HR: 2.056, 95%CI:1.236–3.420, P = 0.005) compared with survival group. After propensity matching, the group which always used β-blocker showed higher rate of all-cause death compare with the control group (61.54% vs 80.77%, P = 0.030).

Conclusions

The risk factors for long-term survival were weight, EuroSCORE, smoking, CPB, IABP, always used β-blockers in patients with LVEF≤35%. The discharge prescription of β-blocker should be cautiously administrated in those patients.

Aortic valve calcification in the era of non-coding RNAs: The revolution to come in aortic stenosis management?

Aortic valve stenosis remains the most frequent structural heart disease, especially in the elderly. During the last decade, we noticed an important consideration and a huge number of publications related to the medical and surgical treatment of this disease. However, the molecular aspect of this degenerative issue has also been more widely studied recently. As evidenced in oncologic but also cardiac research fields, the emergence of microRNAs in the molecular screening and follow-up makes them potential biomarkers in the future, for the diagnosis, follow-up and treatment of aortic stenosis. Herein, we present a review on the implication of microRNAs in the aortic valve disease management. After listing and describing the main miRNAs of interest in the field, we provide an outline to develop miRNAs as innovative biomarkers and innovative therapeutic strategies, and describe a groundbreaking pre-clinical study using inhibitors of miR-34a in a pre-clinical model of aortic valve stenosis.

Bioprosthetic Aortic Valve Replacement in <50 Years Old Patients - Where is the Evidence?

Aortic valve disease is one of the most common valvular heart diseases in the cardiovascular category. Surgical replacement of the diseased aortic valve remains the definitive intervention for most diseases.

There is a clear consensus that in young patients who require aortic valve replacement, a mechanical prosthesis is the preferred choice due to its durable prosthesis without fear of wear and tear over time. However, this comes at the expense of increased risk of bleeding and thromboembolic events; in addition, there is a lack of strict evidence in using bioprosthesis in patients younger than 50 years. The objective of this review article is to assess the current evidence behind using bioprosthetic aortic valve in this young cohort.

Effect of Left Ventricular Reverse Remodeling on Long-term Outcomes After Aortic Valve Replacement

There have been few studies with a large number of patients on the effect of left ventricular (LV) reverse remodeling and long-term outcomes after aortic valve replacement (AVR). This study aimed to investigate long-term outcomes and the prognostic impact of follow-up echocardiographic parameters after AVR. We evaluated 456 consecutive patients from a retrospective multicenter registry in Japan (J-PROVE-Retro) who underwent AVR for aortic valve diseases (predominantly aortic stenosis [AS]; 326 patients and aortic regurgitation [AR]; 130 patients). Preoperative and follow-up echocardiography at 1 year after AVR was evaluated. The primary outcome measure was a composite of cardiac death or hospitalization due to heart failure. The median follow-up period was 9.2 years in AS group and 9.7 years in AR group. The freedom rate from the primary outcome was 92% at 5 years and 79% at 10 years in AS, and 97% at 5 years, and 93% at 10 years in AR. LV end-diastolic and end-systolic diameters, and the LV mass index decreased and LV ejection fraction increased after AVR in both AS and AR, and LV mass index was normalized in more than half of the patients. In the Cox proportional hazard model, echocardiographic parameters at 1 year after AVR were more strongly related to long-term outcomes than preoperative echocardiographic parameters. In conclusion, echocardiographic parameters at 1 year after AVR are more important as predictors of long-term outcomes than preoperative parameters in both AS and AR. More attention should be paid on early postoperative remodeling for long-term follow-up of patients after AVR.

Causes and consequences of cardiac fibrosis in patients referred for surgical aortic valve replacement

Aims

Cardiac fibrosis is associated with left ventricular (LV) remodelling and contractile dysfunction in aortic stenosis (AS). The fibrotic process in this condition is still unclear. The aim of this study was to determine the role of both local and systemic inflammation as underlying mechanisms of LV fibrosis and contractile dysfunction. The diagnostic values of 2D‐strain echocardiography and serum biomarkers in the evaluation of cardiac fibrosis in this condition were assessed through correlation analyses.

Methods and results

Patients with AS referred for surgical valve replacement were prospectively and consecutively included. They all had a comprehensive echocardiography including 2D strain. Blood samples were collected to measure cytokines and inflammatory biomarkers using Luminex bead‐based assays. A per‐surgical myocardial biopsy of the basal antero‐septal segment (S1) was performed. Serial sections of each biopsy were stained with Sirius red. Digital image analysis was used to quantify fibrosis. Immunostainings using specific antibodies against macrophage, glycoprotein (gp) 130, and interleukin 6 (IL‐6) were also performed. Patients were divided into tertiles reflecting the severity of fibrosis: mild, moderate, and severe load (TF1 to TF3). The mean age of the 58 included patients was 73 ± 11 years. Twenty‐four (43%) were in New York Heart Association III–IV. Mean aortic valve area was 0.8 ± 0.2 cm². Mean aortic stenosis peak velocity and mean gradient were respectively 4.5 ± 0.8 m/s and 54 ± 15 mmHg. The mean LV ejection fraction was 54 ± 12%, and the global LV longitudinal strain was −15 ± 4%. The mean S1 strain, corresponding to the biopsied region, was −10 ± 6% and was strongly correlated to fibrosis load (R = 0.83, P < 0.0001). TF3 was associated with higher mortality (P = 0.009), higher serum C‐reactive protein and IL‐6, and lower gp130 compared with the other tertiles (P < 0.05). IL‐6 and gp130 were expressed in the heart and respectively in the plasma membrane of macrophages and in the cytoplasm of both macrophages and cardiomyocytes. During follow‐up, three patients died and were all in the third fibrosis tertile.

Conclusions

We found a positive correlation between elevated inflammatory markers and degree of fibrosis load. These two parameters were associated with worse outcomes in patients with severe AS. Our results may be of interest especially in patients for whom a transcatheter aortic valve implantation is indicated and myocardial biopsy is not possible. Strategies aiming at preventing inflammation might be considered to decrease or limit the progression of cardiac fibrosis in patients followed for AS.

Is left ventricular hypertrophy a friend or foe of patients with aortic stenosis?

Left ventricular hypertrophy (LVH) is traditionally considered a physiological compensatory response to LV pressure overload, such as hypertension and aortic stenosis (AS), in an effort to maintain LV systolic function in the face of an increased afterload. According to the Laplace law, LV wall thickening lowers LV wall stress, which in turn would be helpful to preserve LV systolic performance. However, numerous studies have challenged the notion of LVH as a putative beneficial adaptive mechanism. In fact, the magnitude of LVH is associated with higher cardiovascular morbidity and mortality, especially when LVH is disproportionate to LV afterload. We have briefly reviewed: first, the importance of non-valvular factors, beyond AS severity, for total LV afterload and symptomatic status in AS patients; second, associations of excessive LVH with LV dysfunction and adverse outcome in AS; third, prognostic relevance of the presence or absence of pre-operative LVH in patients referred for aortic valve surgery; fourth, time course, determinants and prognostic implications of LVH regression and LV function recovery after surgical valve replacement and transcatheter aortic valve implantation (TAVI) with a focus on TAVI-specific effects; fifth, the potential of medical therapy to modulate LVH before and after surgical or interventional treatment for severe AS, a condition perceived as a relative contraindication to renin-angiotensin system blockade.

Late Clinical Presentation of Prosthesis-Patient Mismatch Following Transcatheter Aortic Valve Replacement

Prosthesis-patient mismatch (PPM) is relatively common after aortic valve replacement (AVR) and generally is associated with reduced regression of left ventricular (LV) mass. PPM after valve-in-valve transcatheter aortic valve replacement (TAVR) was reported to be 38%. PPM generally is manifested clinically by dyspnea and echocardiographically by high transvalvular gradients. In this E-Challenge, the authors will review a case of a late clinical presentation of PPM 1-year following a valve-in-valve TAVR.

Aortic valve replacement in patients with a left ventricular ejection fraction ≤35% performed via a minimally invasive right thoracotomy

BACKGROUND

We evaluated the outcomes of patients with aortic valve pathology in the setting of a left ventricular ejection fraction ≤35% who underwent minimally invasive aortic valve replacement (AVR), with or without concomitant mitral valve (MV) surgery.

METHODS

All minimally invasive AVR in patients with a left ventricular ejection fraction ≤35%, performed via a right thoracotomy for aortic stenosis or regurgitation between January 2009 and March 2013, were retrospectively evaluated. The operative characteristics, perioperative outcomes, and 30-day mortality were analyzed.

RESULTS

There were 75 patients identified: 51 who underwent isolated AVR, and 24 who had combined AVR plus MV surgery for moderate to severe mitral regurgitation. In patients undergoing MV surgery, there were 22 (91.7%) MV repairs [ring annuloplasty =7 (37.5%), transaortic edge-to-edge repair =15 (62.5%)], and 2 (8.3%) replacements. No patient required conversion to sternotomy for inadequate surgical field exposure. The median total mechanical ventilation time and intensive care unit length of stay were 14 (IQR, 8-20) and 42 hours (IQR, 26-93 hours) in the isolated AVR group, and 16.5 hours (IQR, 12-61.5 hours) and 95.5 hours (IQR, 43.5-159 hours) in the AVR plus MV surgery group, respectively. The most common post-operative complication was new-onset atrial fibrillation, which occurred in 15 (29.4%) isolated AVR and 4 (16.7%) AVR plus MV surgery patients. The median hospital length of stay and 30-day mortality was 7 days (IQR, 5-12 days) and 1 (2%) in the isolated AVR group, and 10.5 days (IQR, 5-21 days) and 1 (4.3%) for AVR plus MV surgery.

CONCLUSIONS

In patients with aortic valve pathology in the setting of a left ventricular ejection fraction ≤35%, minimally invasive AVR can be performed, with or without concomitant MV surgery, with a low morbidity and mortality.

Traditional Sternotomy Versus Minimally Invasive Aortic Valve Replacement in Patients Stratified by Ejection Fraction

OBJECTIVE

Low ejection fraction (EF < 40%) portends adverse outcomes in patients undergoing valvular heart surgery. The role of traditional median sternotomy aortic valve replacement (SAVR) compared with minimally invasive aortic valve replacement (MIAVR) in this cohort remains incompletely understood.

METHODS

A multi-institutional retrospective review of 1503 patients who underwent SAVR (n = 815) and MIAVR via right anterior thoracotomy (n = 688) from 2011 to 2014 was performed. Patients were stratified into two groups: EF of less than 40% and EF of 40% or more. In each EF group, SAVR and MIAVR patients were propensity matched by age, sex, body mass index, race, diabetes, hypertension, dyslipidemia, dialysis, cerebrovascular disease, cardiovascular disease, cerebrovascular accident, peripheral vascular disease, last creatinine level, EF, previous MI and cardiogenic shock, and the Society for Thoracic Surgeons (STS) score.

RESULTS

Among patients with an EF of 40% or more (377 pairs), patients who underwent MIAVR compared with SAVR had decreased intensive care unit hours (56.8% vs 84.6%, P < 0.001), postoperative length of stay (7.1 vs 7.9 days, P = 0.04), incidence of atrial fibrillation (18.8% vs 38.7%, P < 0.001), bleeding (0.8% vs 3.2%, P = 0.04), and a trend toward decreased 30-day mortality (0.3% vs 1.3%, P = 0.22). The STS scores were largely equivalent in patients undergoing MIAVR compared with SAVR (2.4% vs 2.6%, P = 0.09). In patients with an EF of less than 40% (35 pairs), there was no difference in intensive care unit hours (69% vs 72.6%, P = 0.80), postoperative length of stay (10.3 vs 7.2 days, P = 0.13), 30-day mortality (3.8% vs 0.8%, P = 0.50), or the STS score (3.3% vs 3.2%, P = 0.68).

CONCLUSIONS

Minimally invasive aortic valve replacement in patients with preserved EF was associated with improved short-term outcomes compared with SAVR. In patients with left ventricular dysfunction, short-term outcomes between MIAVR and SAVR are largely equivalent.

Modulating microRNAs in cardiac surgery patients: Novel therapeutic opportunities?

This review focuses on microRNAs (miRs) in cardiac surgery, where they are emerging as potential targets for therapeutic intervention as well as novel clinical biomarkers. Identification of the up/down-regulation of specific miRs in defined groups of cardiac surgery patients can lead to the development of novel strategies for targeted treatment in order to maximise therapeutic results and minimise acute, delayed or chronic complications. MiRs could also be involved in determining the outcome independently of complications, for example in relation to myocardial perfusion and fibrosis. Because of their relevance in disease, their known sequence and pharmacological properties, miRs are attractive candidates for therapeutic manipulation. Pharmacological inhibition of individual miRs can be achieved by modified antisense oligonucleotides, referred to as antimiRs, while miR replacement can be achieved by miR mimics to increase the level of a specific miR. MiR mimics can restore the function of a lost or down-regulated miR, while antimiRs can inhibit the levels of disease-driving or aberrantly expressed miRs, thus de-repressing the expression of mRNAs targeted by the miR. The main delivery methods for miR therapeutics involve lipid-based vehicles, viral systems, cationic polymers, and intravenous or local injection of an antagomiR. Local delivery is particularly desirable for miR therapeutics and options include the development of devices specific for local delivery, light-induced antimiR, and vesicle-encapsulated miRs serving as therapeutic delivery agents able to improve intracellular uptake. Here, we discuss the potential therapeutic use of miRNAs in the context of cardiac surgery.

Calcific Aortic Valve Disease: Part 2-Morphomechanical Abnormalities, Gene Reexpression, and Gender Effects on Ventricular Hypertrophy and Its Reversibility

In part 1, we considered cytomolecular mechanisms underlying calcific aortic valve disease (CAVD), hemodynamics, and adaptive feedbacks controlling pathological left ventricular hypertrophy provoked by ensuing aortic valvular stenosis (AVS). In part 2, we survey diverse signal transduction pathways that precede cellular/molecular mechanisms controlling hypertrophic gene expression by activation of specific transcription factors that induce sarcomere replication in-parallel. Such signaling pathways represent potential targets for therapeutic intervention and prevention of decompensation/failure. Hypertrophy provoking signals, in the form of dynamic stresses and ligand/effector molecules that bind to specific receptors to initiate the hypertrophy, are transcribed across the sarcolemma by several second messengers. They comprise intricate feedback mechanisms involving gene network cascades, specific signaling molecules encompassing G protein-coupled receptors and mechanotransducers, and myocardial stresses. Future multidisciplinary studies will characterize the adaptive/maladaptive nature of the AVS-induced hypertrophy, its gender- and individual patient-dependent peculiarities, and its response to surgical/medical interventions. They will herald more effective, precision medicine treatments.

Recent advances in transcatheter aortic valve replacement for high-risk patients

Aortic stenosis is the most common valvular heart disease of old age. Patients with severe aortic stenosis who develop symptoms have a very poor prognosis without valve intervention. Surgical aortic valve replacement has historically been the only treatment option for these patients. However a significant minority are considered inoperable or at high surgical risk and therefore are refused or decline surgery. In recent years, transcatheter aortic valve replacement has emerged as an alternative treatment option in these high-risk patients. The aim of this review is to summarize the current role of transcatheter aortic valve replacement in contemporary clinical practice including recent advances in technological and procedural aspects and then discuss future directions.

Sex Differences in Aortic Stenosis and Outcome Following Surgical and Transcatheter Aortic Valve Replacement

Aortic stenosis is the commonest valve defect in the developed world and is associated with a high mortality once symptomatic. There is a difference in the way that male and female hearts remodel in the face of chronic pressure overload: women develop a concentrically hypertrophied, small cavity left ventricle (LV), whereas men are more prone to the development of eccentric hypertrophy. At a cellular level, there is an increase in collagen and metalloproteinase gene expression in males suggesting a different regulation of extracellular volume composition according to sex. Male hearts with aortic stenosis appear to have more fibrosis than their female comparators. The trigger for this appears to be in part related to estrogen receptor signaling, but other factors such as renin-angiotensin activation, nitric oxide, and circulating noradrenaline levels may also be implicated. Treatment options include surgical valve replacement (SAVR) and more recently transcatheter aortic valve replacement (TAVR). Female sex may be a risk factor for adverse outcome following SAVR and conversely appears to confer a survival advantage when undergoing TAVR. Whether the lower mortality seen following TAVR in women compared with men (despite their increased age and frailty) reflects their longer life expectancy, smaller annular size (and less post-TAVR aortic regurgitation), more favorable LV reverse remodeling, or more likely, a combination of these factors remains to be established.

The impact of transcatheter aortic valve implantation on left ventricular performance and wall thickness - single-centre experience

INTRODUCTION

Transcatheter aortic valve implantation (TAVI) is a treatment alternative for the elderly population with severe symptomatic aortic stenosis (AS) at high risk for surgical aortic valve replacement (SAVR).

AIM

To assess the impact of TAVI on echocardiographic parameters of left ventricular (LV) performance and wall thickness in patients subjected to the procedure in a single-centre between 2009 and 2013.

MATERIAL AND METHODS

The initial group consisted of 170 consecutive patients with severe AS unsuitable for SAVR. Logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) was 21.73 ±12.42% and mean age was 79.9 ±7.5 years.

RESULTS

The TAVI was performed in 167 (98.2%) patients. Mean aortic gradient decreased significantly more rapidly after the procedure (from 58.6 ±16.7 mm Hg to 11.9 ±4.9 mm Hg, p < 0.001). The LV ejection fraction (LVEF) significantly increased in both short-term and long-term follow-up (57 ±14% vs. 59 ±13%, p < 0.001 and 56 ±14% vs. 60 ±12%, p < 0.001, respectively). Significant regression of interventricular septum diameter at end-diastole (IVSDD) and end-diastolic posterior wall thickness (EDPWth) was noted in early (15.0 ±2.4 mm vs. 14.5 ±2.3 mm, p < 0.001 and 12.7 ±2.1 mm vs. 12.4 ±1.9 mm, p < 0.028, respectively) and late post-TAVI period (15.1 ±2.5 mm to 14.3 ±2.5 mm, p < 0.001 and 12.8 ±2.0 mm to 12.4 ±1.9 mm, p < 0.007, respectively). Significant paravalvular leak (PL) was noted in 21 (13.1%) patients immediately after TAVI and in 13 (9.6%) patients in follow-up (p < 0.001). Moderate or severe mitral regurgitation (msMR) was seen in 24 (14.9%) patients from the initial group and in 19 (11.8%) patients after TAVI (p < 0.001).

CONCLUSIONS

The TAVI had an immediate beneficial effect on LVEF, LV walls thickness, and the incidence of msMR. The results of the procedure are comparable with those described in other centres.

A critical review of hemodynamic changes and left ventricular remodeling after surgical aortic valve replacement and percutaneous aortic valve replacement

The introduction of transcatheter aortic valve replacement (TAVR) in clinical practice has widened options for symptomatic patients at high surgical risk; however, it is not known whether TAVR has equivalent or prolonged benefits in terms of left ventricular (LV) remodeling.

METHODS

To explore the relative hemodynamic benefits and postoperative LV remodeling associated with TAVR and surgical aortic valve replacement (SAVR), we performed a critical review of the available literature. A total of 67 studies were included in this systematic review.

RESULTS

There is at least equivalent if not slightly superior hemodynamic performance of TAVR over SAVR, and TAVR showed lower prosthesis-patient mismatch compared with SAVR. However, LV mass appears to regress to a greater degree after SAVR compared with TAVR. Aortic regurgitation, paravalvular in particular, is more common after TAVR than SAVR, although it is rarely more than moderate in severity. Improvements in diastolic function and mitral regurgitation are reported in only a handful of studies each and could not be compared across prosthesis types.

CONCLUSIONS

The published data support the hemodynamic comparability of SAVR and TAVR, with the higher incidence of prosthesis-patient mismatch in SAVR offset by higher incidence of paravalvular leak in TAVR. These results highlight the need for further studies focusing on hemodynamic changes after valve therapy.

Hemodynamic outcomes of transcatheter aortic valve implantation with the CoreValve system: an early assessment

BACKGROUND AND AIMS

Transcatheter aortic valve implantation (TAVI) is an established method for the treatment of high-risk patients with aortic stenosis (AS). The beneficial effects of TAVI in cardiac hemodynamics have been described in recent studies, but those investigations were mostly performed after an interval of more than 6 months following aortic valve implantation. The aim of this study is to investigate the acute and short-term alterations in hemodynamic conditions using the echocardiography outcomes in patients undergoing TAVI.

METHODS AND RESULTS

A total of 60 patients (26 males, 34 females; age 84·7 ± 5·8) who underwent TAVI with CoreValve system were included in the study. Echocardiography was performed before hospital discharge and at 3 months follow-up. As expected, TAVI was associated with an immediate significant improvement in aortic valve area (AVA) (from 0·64 ± 0·16 cm(2) to 1·67 ± 0·41 cm(2) , P-value<0·001) and mean gradient (from 51·9 ± 15·4 mmHg to 8·8 ± 3·8 mmHg, P-value<0·001). At 3-month follow-up, systolic LV function was augmented (EF: 50 ± 14% to 54 ± 11%, P-value = 0·024). Left ventricle (LV) mass and left atrium (LA) volume were significantly reduced (LV mass index from 126·5 ± 30·5 g m(-2) to 102·4 ± 32·4 g m(-2) ; LA index from 42·9 ± 17·3 ml m(-2) to 33·6 ± 10·6 ml m(-2) ; P-value<0·001 for both). Furthermore, a decrement in systolic pulmonary artery pressure (SPAP) from 47·5 ± 13·5 mmHg to 42·5 ± 11·2 mmHg, P-value = 0·02 was also observed. Despite the high incidence of paravalvular regurgitation (PVR) (80%), most of the patients presented mild or trace PVR and no significant progress of the regurgitation grade was seen after 3 months.

CONCLUSION

This study demonstrates that the beneficial effects of TAVI in cardiac function and hemodynamics occur already after a short period following aortic valve implantation.

Predictors of improvement in diastolic function after transcatheter aortic valve implantation

BACKGROUND

Aortic stenosis is associated with concentric left ventricle (LV) hypertrophy or remodeling resulting in impaired diastolic function and elevated left-sided filling pressure. We investigated the changes in LV geometry and LV filling hemodynamics, giving emphasis to parameters associated with changes in diastolic function after transcatheter aortic valve implantation (TAVI).

METHODS

Comprehensive diastolic assessment was performed before and six months after TAVI in 70 patients with severe aortic stenosis. Patients with any degree of mitral stenosis or >mild left-sided valvular regurgitation were excluded.

RESULTS

In the entire cohort six months after TAVI, LV end-diastolic diameter increased (44.1 ± 6 versus 45 ± 6 mm, P = 0.02), whereas LV mass and relative wall thickness (RWT) decreased (270.1 ± 76 versus 245.1 ± 75 g and 0.53 ± 0.15 versus 0.46 ± 0.1, respectively; P < 0.0001 for both). Lateral e' increased (5.8 ± 2 versus 6.6 ± 3 cm/s, P = 0.03) and left atrium (LA) volume, E/e' ratio, and systolic pulmonary pressure decreased (88.1 ± 30 versus 80 ± 28 cc, 18 ± 7.8 versus 16.3 ± 5.5, and 42.7 ± 14.9 versus 38.7 ± 12 mmHg, respectively; P < 0.05 for all), suggesting reduction in LA pressure. The improvement in LA volume and E/e' was almost exclusively seen in patients with LV hypertrophy before TAVI (P < 0.05 both), as opposed to patients with concentric remodeling.

CONCLUSIONS

In our preliminary study, TAVI resulted in LV and LA reverse remodeling, and improved LV relaxation and LA filling pressure in patients with severe aortic stenosis and concentric hypertrophy. Patients with concentric remodeling at baseline seem to have limited improvement in LV diastolic function and filling pressure following TAVI, but larger clinical trials would be required to conclude if they have no improvement at all.

Impact of aortic prosthesis-patient mismatch on left ventricular mass regression

Background

Prostheses used for aortic valve replacement may be small in relation to body size, causing prosthesis-patient mismatch and delaying left ventricular mass regression. This study examined the effect of prosthesis-patient mismatch on regression of left ventricular mass after aortic valve replacement.

Methods

We prospectively studied 96 patients undergoing aortic valve replacement between 2007 and 2012. Mean and peak gradients and indexed effective orifice area were measured by transthoracic echocardiography at 3 and 6 months postoperatively. Patient-prosthesis mismatch was defined as indexed effective orifice area ≤0.85 cm2·m−2.

Results

Moderate prosthesis-patient mismatch was present in 25% of patients. There were no significant differences in demographic and operative data between patients with and without prosthesis-patient mismatch. Left ventricular dimensions, posterior wall thickness, transvalvular gradients, and left ventricular mass decreased significantly after aortic valve replacement in both groups. The interventricular septal diameter and left ventricular mass index regression, and left ventricular ejection fraction were better in patients without prosthesis-patient mismatch. There was a significant positive correlation between the postoperative indexed effective orifice area of each valve prosthesis and the rate of left ventricular mass regression.

Conclusions

Prosthesis-patient mismatch leads to higher transprosthetic gradients and impaired left ventricular mass regression. A small-sized valve prosthesis does not necessarily result in prosthesis-patient mismatch, and may be perfectly adequate in patient with small body size.

A systematic review on the quality of life benefits after aortic valve replacement in the elderly

BACKGROUND

Surgical aortic valve replacement is being increasingly performed in elderly patients with good perioperative outcomes and long-term survival. Evidence is limited on health-related quality of life after aortic valve replacement, which is an important measure of operative success in the elderly.

METHODS

A systematic review of clinical studies after January 2000 was performed to identify health-related quality of life in the elderly after aortic valve replacement. Strict inclusion and exclusion criteria were applied. Quality appraisal of each study also was performed using predefined criteria. Health-related quality of life results were synthesized through a narrative review with full tabulation of the results of all included studies.

RESULTS

Health-related quality of life improvements were shown across most or all domains in different health-related quality of life instruments. Elderly patients experienced marked symptomatic improvement. Health-related quality of life was equivalent or superior to both an age-matched population and younger patients undergoing identical procedures. There were excellent functional gains after surgery, but elderly patients remain susceptible to geriatric issues and mood problems. Concomitant coronary artery bypass did not affect health-related quality of life. There was a diverse range of study designs, methods, and follow-up times that limited direct comparison between studies.

CONCLUSIONS

Aortic valve replacement results in significant health-related quality of life benefits across a broad range of health domains in elderly patients. Age alone should not be a precluding factor for surgery. Data are heterogeneous and mostly retrospective. We recommend future studies based on consistent guidelines provided in this systematic review.

Prolonged total isovolumic time is related to reduced long-axis functional recovery following valve replacement surgery for severe aortic stenosis

BACKGROUND

The left ventricular (LV) long axis (Lax) function is very sensitive in documenting myocardial abnormalities in aortic stenosis (AS). We hypothesized that Lax recovery after aortic valve replacement (AVR) is related to the extent of cavity dyssynchrony measured by total isovolumic time (t-IVT).

METHODS

A consecutive 107 patients (aged 70 ± 7 years, 70 male) with severe AS and Lax impairment were studied. T-IVT was measured before and after AVR. Reduced Lax function and its post-operative recovery were defined as mitral annular plane systolic excursion (MAPSE) ≦10 mm and an increase of MAPSE >10%, respectively.

RESULTS

LV function improved (EF: 43 ± 8 to 48 ± 10%; MAPSE: 7.9 ± 1.0 to 11.0 ± 2.4 mm) and t-IVT shortened (9.7 ± 3.7 to 7.0 ± 2.8s/min, p<0.01 for all) after AVR. Sixty-five (61%) patients had Lax recovery after a median of 32-month follow-up. Univariate predictors were LV size, LA dimensions, the presence of restrictive LV filling and prolonged t-IVT. Only LV end-systolic dimension, restrictive filling and t-IVT (OR 0.61, 95% CI 0.47-0.79, p<0.01) were independent predictors. A pre-operative t-IVT ≦ 9.3s/min was 81% sensitive and 63% specific in predicting Lax recovery (AUC 0.81, p<0.001). The prevalence of CAD or concomitant CABG were similar in 2 patient groups with different t-IVT.

CONCLUSIONS

Lax recovery was evident in the majority of AS patients after AVR. The lower prevalence of Lax recovery seen in patients with prolonged t-IVT suggests that dyssynchrony may play an important role in the process of adverse LV remodeling.

A practical guide to multimodality imaging of transcatheter aortic valve replacement

The advent of transcatheter aortic valve replacement (TAVR) is one of the most widely anticipated advances in the care of patients with severe aortic stenosis. This procedure is unique in many ways, one of which is the need for a multimodality imaging team-based approach throughout the continuum of the care of TAVR patients. Pre-procedural planning, intra-procedural implantation optimization, and long-term follow-up of patients undergoing TAVR require the expert use of various imaging modalities, each of which has its own strengths and limitations. Divided into 3 sections (pre-procedural, intraprocedural, and long-term follow-up), this review offers a single source for expert opinion and evidence-based guidance on how to incorporate the various modalities at each step in the care of a TAVR patient. Although much has been learned in the short span of time since TAVR was introduced, recommendations are offered for clinically relevant research that will lead to refinement of best practice strategies for incorporating multimodality imaging into TAVR patient care.

Global longitudinal strain is a strong independent predictor of all-cause mortality in patients with aortic stenosis

AIMS

To assess the capacity of global longitudinal strain (GLS) in patients with aortic stenosis (AS) to (i) detect the subclinical left ventricular (LV) dysfunction [LV ejection fraction (LVEF) ≥50% patients]; (ii) predict all-cause mortality and major adverse cardiac events (MACE) (all patients), and (iii) provide incremental prognostic information over current risk markers.

METHODS AND RESULTS

Patients with AS (n = 146) and age-matched controls (n = 12) underwent baseline echocardiography to assess AS severity, conventional LV parameters and GLS via speckle tracking echocardiography. Baseline demographics, symptom severity class and comorbidities were recorded. Outcomes were identified via hospital record review and subject/physician interview. The mean age was 75 ± 11, 62% were male. The baseline aortic valve (AV) area was 1.0 ± 0.4 cm(2) and LVEF was 59 ± 11%. In patients with a normal LVEF (n = 122), the baseline GLS was controls -21 ± 2%, mild AS -18 ± 3%, moderate AS -17 ± 3% and severe AS -15 ± 3% (P< 0.001). GLS correlated with the LV mass index, LVEF, AS severity, and symptom class (P< 0.05). During a median follow-up of 2.1 (inter-quartile range: 1.8-2.4) years, there were 20 deaths and 101 MACE. Unadjusted hazard ratios (HRs) for GLS (per %) were all-cause mortality (HR: 1.42, P< 0.001) and MACE (HR: 1.09, P< 0.001). After adjustment for clinical and echocardiographic variables, GLS remained a strong independent predictor of all-cause mortality (HR: 1.38, P< 0.001).

CONCLUSIONS

GLS detects subclinical dysfunction and has incremental prognostic value over traditional risk markers including haemodynamic severity, symptom class, and LVEF in patients with AS. Incorporation of GLS into risk models may improve the identification of the optimal timing for AV replacement.

Percutaneous Valve Therapy: Choosing the Appropriate Patients and Outcomes

Surgical aortic valve replacement (SAVR) is the current gold standard for the treatment of severe symptomatic aortic stenosis (AS), but transcatheter aortic valve implantation (TAVI) currently represents a viable alternative to conventional SAVR for patients with AS at high risk of operative mortality. On multivariate analysis it has been shown that female gender is independently associated with better recovery of the left ventricular systolic function after TAVI and that left ventricular hypertrophy reverses more frequently in female patients after SAVR. During follow-up, however, women remain significantly more symptomatic compared with men, mainly because they present with more advanced valve disease at a significantly older age.

Residual compromised myocardial contractile reserve after valve replacement for aortic stenosis

OBJECTIVE

Despite recovery of left ventricular (LV) function and morphology after aortic valve replacement (AVR) for aortic stenosis (AS), its relationship with exercise capacity remains unknown. Twenty-one AVR patients (age 61 ± 12 years, 14 male) with normal ejection fraction (EF, 64 ± 7%) and 21 age- and sex-matched controls (57 ± 9 years, 10 male, EF 68 ± 8%) were studied.

METHODS AND RESULTS

All subjects performed semi-supine bicycle exercise and speckle tracking echocardiography (STE) study. Peak oxygen consumption (pVO(2)) was collected during semi-supine bicycle exercise. Systolic (GLSRs) and early diastolic (GLSRe) longitudinal strain rate using STE and Doppler echocardiographic parameters were measured at rest, submaximal, peak exercise, and 4 min after exercise. The two groups had comparable resting echocardiographic measurements. At peak exercise, pVO(2) was lower in patients than controls (18.5 ± 4.5 vs. 22.1 ± 4.3 L/min/kg, P < 0.05). GLSRs (0.98 ± 0.28 vs. 1.55 ± 0.30 1/s, P < 0.001), septal Sm (7.9 ± 1.4 vs. 11.1 ± 2.3 cm/s, P < 0.001) and their changes between rest and peak exercise (ΔGLSRs: 0.16 ± 0.33 vs. 0.68 ± 0.27 1/s, P < 0.001; ΔSm 2.29 ± 2.23 vs. 4.63 ± 2.29 cm/s, P < 0.01) were significantly lower in patients than controls. There was no correlation between pVO(2) and any echocardiographic measurements in controls. In patients, pVO(2) correlated with peak exercise GLSRs (r = 0.60, P = 0.0007), septal Sm (r = 0.65, P = 0.002), and Em (r = 0.57, P = 0.009). In a multivariate model, peak exercise GLSRs (β = 7.18, P = 0.03) was the only independent predictor of pVO(2) in the patients group.

CONCLUSION

Exercise capacity is subnormal after AVR for AS, irrespective of normal LVEF suggesting residual compromised myocardial functional reserve.

Left and right ventricular function in aortic stenosis patients 8 weeks post-transcatheter aortic valve implantation or surgical aortic valve replacement

AIMS

Knowledge of longitudinal left and right ventricular (LV and RV) function after transcatheter aortic valve implantation (TAVI) is scarce. We hypothesized that the longitudinal systolic biventricular function in aortic stenosis (AS) patients is affected differently by TAVI and surgical aortic valve replacement (SAVR).

METHODS AND RESULTS

Thirty-three AS patients (all-TAVI group, age 81 ± 9 years, 18 female), with EuroSCORE 18 ± 9%, were accepted for TAVI. Seventeen of these patients were matched (by gender, age, and LV function) to 17 patients undergoing SAVR. Conventional echocardiographic parameters, systolic atrioventricular plane displacement (AVPD) at standard sites and peak systolic velocity (PSV) by pulsed tissue Doppler at basal RV free wall, LV lateral wall, and septum were studied before and 8 weeks after the procedure. Procedural success was 100%, and 30-day mortality 9%. In all TAVI patients, AVPD(lateral), PSV(lateral), AVPD(septal), and PSV(septal) increased (P< 0.001, 0.003, 0.006 and 0.002). When studying the matched patients postoperatively, both the SAVR and TAVI patients had increased PSV(lateral) and AVPD(lateral) (SAVR: P=0.03 and P=0.04, TAVI: P=0.04 and P=0.01). The PSV(RV) increased in the all-TAVI group (P=0.007), while the AVPD(RV) was unchanged. SAVR patients had decreased AVPD(RV) (P=0.001) and PSV(RV) (P=0.004), while the matched TAVI patients had unchanged RV function parameters.

CONCLUSION

An improvement in regional longitudinal LV function in the septal and lateral wall could be seen after TAVI. Among the matched patients, both the TAVI and SAVR patients seemed to improve LV function in the lateral wall. RV systolic function increased in TAVI patients, but was impaired in the matched SAVR group at the 8-week follow-up.

One-year results of transcatheter aortic valve implantation in severe symptomatic aortic valve stenosis

Transcatheter aortic valve implantation (TAVI) is an alternative therapy for symptomatic severe aortic valve stenosis in high-risk patients with several co-morbidities. We evaluated the 1-year effects of TAVI on quality of life, exercise capacity, neurohormonal activation, and myocardial hypertrophy. From June 2008 to October 2009, consecutive patients aged ≥75 years with symptomatic severe aortic valve stenosis (area <1 cm(2)) and a logistic euroSCORE ≥15% or aged >60 years with additional specified risk factors underwent TAVI. An aortic valve prosthesis (CoreValve) was inserted in a retrograde fashion. Examinations were performed before and 30 days and 1 year after TAVI. An assessment of the quality of life (Minnesota Living with Heart Failure Questionnaire), a 6-minute walking test, measurement of B-type natriuretic peptide, and echocardiography were performed. In 51 patients (mean age 78 ± 6.6 years, mean left ventricular ejection fraction 58.4 ± 12.2%), the follow-up examinations were performed after TAVI. The 1-year follow-up visit after TAVI revealed significantly improved quality of life (baseline Minnesota Living with Heart Failure Questionnaire score 39.6 ± 19 vs 26.1 ± 18, p <0.001) and more distance covered in the 6-minute walking test (baseline 185 ± 106 vs 266 ± 118 m, p <0.001). The B-type natriuretic peptide level had decreased (baseline 642 ± 634 vs 323 ± 266 pg/ml, p <0.001), and the left ventricular mass index had decreased (156 ± 45 vs 130 ± 42 g/m(2), p <0.001). The left ventricular diameter and ejection fraction remained unchanged. In conclusion, TAVI leads to significantly reduced neurohormonal activation, regression of myocardial hypertrophy, and lasting enhancement of quality of life and exercise capacity in patients with symptomatic and severe aortic stenosis 1 year after intervention.

Perioperative and long-term outcomes following aortic valve replacement: a population cohort study of 4124 consecutive patients

OBJECTIVE

Because of increasing life expectancy, more patients require valve replacement for aortic stenosis. We aimed to determine perioperative and long-term outcomes, the factors associated with these and whether they have changed over time.

METHODS

We undertook a retrospective cohort study of all 4124 patients, who underwent isolated, primary aortic valve replacement in Scotland between April 1996 and March 2009 inclusive.

RESULTS

Annual operations increased by 68%, from 261 to 439. The overall risk of dying within 30 days, 5 years and 10 years was 3.4%, 19.9% and 38.5%, respectively. Over 10 years' follow-up, 4.4% underwent further valve surgery, 7.9% suffered a stroke and 5.3% a myocardial infarction. Age, renal impairment and urgency were predictors of both perioperative and long-term death. Perioperative death was associated with left-ventricular impairment and long-term death with respiratory disease, diabetes and deprivation. Over the 13 years, there was an increase in median age (from 66 to 69 years, p < 0.001), diabetes (from 1.9% to 12.6%, p < 0.001), hypertension (from 26.4% to 56.1%, p < 0.001), cerebrovascular disease (from 3.7% to 9.8%, p < 0.001), respiratory disease (from 6.6% to 9.7%, p = 0.020) and previous myocardial infarction (from 0.6% to 5.8%, p < 0.001), but the risk of perioperative death fell from 6.5% to 3.1% (odds ratio (OR) 0.87, 95% confidence interval (CI) 0.83, 0.92, p < 0.001) per year.

CONCLUSIONS

Patients undergoing aortic valve replacement have a poor risk profile. Over time, their numbers, age and co-morbidity have increased. In spite of these, there has been a significant reduction in the risk of perioperative death.

Hemodynamic results and changes in myocardial function after transcatheter aortic valve implantation

BACKGROUND

This prospective study was designed to evaluate the hemodynamic results of transcatheter aortic valve implantation (TAVI) with the CoreValve prosthesis (Medtronic, Minneapolis, Minnesota) and the effects on left ventricular function.

METHODS

From June 2008 to June 2009, consecutive patients with severe symptomatic aortic valve stenosis (aortic valve area <1 cm(2)) and the indication for TAVI were included. Aortic valve prosthesis was inserted retrograde. Examinations of study patients were performed before, 30 days, and 6 months after TAVI and comprised measurement of B-type natriuretic peptide and echocardiography. Severe prosthesis-patient mismatch was defined as an indexed effective aortic valve area < or =0.65 cm(2)/m(2).

RESULTS

In 39 patients, follow-up examinations were performed after TAVI. Severe prosthesis-patient mismatch seldom occurred (n = 1), but mild to moderate aortic valve regurgitation due to paravalvular leaks was common (n = 24, 62%). After 6 months, left ventricular mass index declined (158 +/- 46 vs 138 +/- 45 g/m(2), P = .001), and peak early diastolic mitral annular velocity (E') and peak systolic mitral annular velocity (S') increased (P = .004 and P < .001, respectively). B-type natriuretic peptide levels decreased (744 +/- 708 at baseline vs 367 +/- 273 at 30 days, P = .003, 279 +/- 186 pg/mL at 6 months, P = .001). Left ventricular diameters and ejection fraction remained unchanged.

CONCLUSION

Despite the high incidence of paravalvular regurgitation after TAVI, hemodynamic results were favorable. Furthermore, TAVI had positive effects on left ventricular remodeling and improved neurohormonal activity, myocardial hypertrophy, and diastolic function.

Left ventricular and ascending aortic function after stenting of native coarctation of aorta

Patients with surgically corrected aortic coarctation have increased proximal aortic stiffness that might contribute to the known worse cardiovascular outcomes. We examined the effect of stenting on the mid-term ascending aortic elastic properties and its relation to cardiac structure and function in adults with native coarctation of the aorta. A total of 20 consecutive patients (13 men, age at stenting 30 + or - 8 years) were prospectively studied before and 14 + or - 2 months after coarctation stenting. The aortic stiffness index was calculated using the ascending aortic diameters and right arm blood pressure values. The ventricular long-axis function was assessed using pulsed-wave tissue Doppler imaging at the septal site. The results were compared to those from 31 normal controls. Statistically significant improvement was found in aortic narrowing (catheter-derived gradient 32 + or - 11 vs 10 + or - 6 mm Hg), left ventricular mass index (132.8 + or - 50.1 vs 114.7 + or - 47.7 g/m(2)), long-axis function, and left atrial volume index (26.5 + or - 5.3 vs 23.7 + or - 5.6 mm(3)/m(2)). The patients continued to have a thicker left ventricle, reduced long-axis function, and larger left atrium after intervention than did the controls. They also had impaired proximal aortic function with respect to the controls that remained unchanged after stenting (aortic stiffness index 10.7 + or - 4.5 to 10.1 + or - 3.0). The poststenting aortic stiffness index correlated modestly with the left ventricular mass index and reduced long-axis velocity. In conclusion, aortic stenting resulted in partial mid-term improvement in cardiac structure and function in adults with coarctation of aorta but the ascending aortic elastic properties remained abnormal. Such a degree of impairment was related to residual left ventricular hypertrophy and dysfunction. Early identification of such patients and optimum management might avoid these irreversible ventriculoaortic disturbances and their known consequences.

Sequential changes in myocardial function after valve replacement for aortic stenosis by speckle tracking echocardiography

AIMS

Regional myocardial function may change differently in different pathology. Speckle tracking echocardiography (STE) was applied to evaluate longitudinal, radial, and circumferential function in patients with aortic stenosis (AS) before, within 1 week, and 6 months after aortic valve replacement (AVR).

METHODS AND RESULTS

In 40 consecutive patients with severe AS, we acquired apical four-, three-, and two-chamber views and standard short-axis view pre- and post-AVR and after 6 months. Longitudinal, radial, and circumferential (LS, RS, and CS) were calculated by commercial STE software. Further, we analysed diastolic myocardial function by measuring E/e' ratio. With AVR, valve area increased and remained stable at 6 months follow-up. Left ventricular mass was unchanged 1 week after AVR (270 +/- 58 g vs. 267 +/- 58 g, n.s.) but decreased significantly during the next 6 months (219 +/- 50 g, P < 0.05). Left ventricular ejection fraction remained unchanged. Strain values did not change significantly within 1 week after AVR but increased significantly after 6 months (LS by 16%, RS by 21%, and CS by 28% of baseline values). E/e' ratio was highly augmented before AVR (26.1 +/- 12.5) and decreased significantly 6 months after AVR (15.9 +/- 5.9).

CONCLUSION

Myocardial function significantly recovers after replacing the stenosed aortic valve. However, there is a considerable difference between the response of longitudinal, radial, and circumferential function. Our data suggest that echocardiographic assessment of regional function is feasible and of potential clinical importance.

The European System for Cardiac Operative Risk Evaluation (EuroSCORE) is not appropriate for withholding surgery in high-risk patients with aortic stenosis: a retrospective cohort study

BACKGROUND

The European System for Cardiac Operative Risk Evaluation (EuroSCORE) is a widely used risk assessment tool in patients with severe aortic stenosis to determine operability and to select patients for alternative therapies such as transcatheter aortic valve implantation. The objective of this study was to determine the accuracy of the EuroSCORE in predicting mortality following aortic valve replacement (AVR).

METHODS

The logistic EuroSCORE was determined for all consecutive patients that underwent conventional AVR between 1995 and 2005 at our institution. Provincial Vital Statistics were used to determine all-cause mortality. The accuracy of the prognostic risk prediction provided by logistic EuroSCORE was assessed by comparing observed and expected operative mortality.

RESULTS

During the study period, a total of 1,421 patients underwent AVR including 237 patients (16.7%) that had a logistic EuroSCORE > 20. Among these patients, the mean predicted operative mortality was 38.7% (SD = 18.1). The actual mortality of these patients was significantly lower than that predicted by EuroSCORE (11.4% vs. 38.7%, observed/expected ratio 0.29, 95% CI 0.15-0.52, P < 0.05). The EuroSCORE overestimated mortality within all strata of predicted risk. Although medium-term mortality is significantly higher among patients with EuroSCORE > 20 (log rank P = 0.0001), approximately 60% are alive at five years.

CONCLUSION

Actual operative mortality in patients undergoing AVR is significantly lower than that predicted by the logistic EuroSCORE. Additionally, medium-term survival following AVR is acceptable in high-risk patients with EuroSCORE > 20. More accurate risk prediction models are needed for risk-stratifying patients with severe aortic stenosis.