Evolving Concept of Aortic Valve Replacement in Asymptomatic Patients With Severe Aortic Stenosis

BACKGROUND

Surgical treatment of asymptomatic severe aortic stenosis (AS) has been gaining attention ever since the results of the Early Surgery Versus Conventional Treatment in Very Severe Aortic Stenosis (RECOVERY) and Aortic Valve replacement versus conservative treatment in Asymptomatic seveRe aortic stenosis (AVATAR) trials showed survival benefits with early surgical aortic valve replacement (SAVR). This study analyzed the long-term clinical and echocardiographic outcomes of SAVR in asymptomatic severe AS.

METHODS

Between 2002 and 2020, 272 patients with asymptomatic severe AS and a left ventricular ejection fraction ≥50% underwent SAVR with or without concomitant aortic surgery and met the study criteria. The median follow-up was 8.5 years (interquartile range, 6-12.8 years), for a total of 2584 patient-years. The time course of the left ventricular mass index (LVMI) and the average E/E' (ratio of the Doppler-derived E wave to the tissue Doppler-derived E' wave) were assessed using 594 postoperative echocardiograms. The association of preoperative LVMI and average E/E' with survival was assessed using Cox proportional hazards.

RESULTS

There was no operative mortality. On longitudinal analyses, LVMI improved in patients who presented with moderate or severe preoperative left ventricular hypertrophy (LVH). However, after the early decline in average E/E', there was a late increase to greater than upper limit normal, particularly in patients with a preoperative average E/E'≥14. Postoperative survival was 100%, 94%, 84%, and 76% at 1, 5, 10, and 15 years, respectively, comparable to age- and sex-matched expected survival on the basis of the US general population. On adjusted Cox survival analysis, only moderate to severe LVH was associated with a survival penalty (hazard ratio], 2.32; 95% CI, 1.02-5.27; P = .045).

CONCLUSIONS

In asymptomatic patients with AS, SAVR restores survival and improves LVH, but patients with diastolic dysfunction are left with persistent dysfunction. Presentation with moderate or severe LVH at the time of surgery translated to a survival penalty. This observational study supports early SAVR in this population before development of LVH, although further investigation is needed.

Prognostic impact of main pulmonary artery to ascending aorta diameter ratio in patients with severe aortic stenosis underwent transcatheter aortic valve implantation

BACKGROUND

Pulmonary hypertension (PH) and right ventricular dysfunction are poor prognostic predictors in patients underwent transcatheter aortic valve implantation (TAVI) for severe aortic stenosis (AS).

AIMS

The prognostic impact of the main pulmonary artery/ascending aorta diameter ratio (MPA/AOr), measured simply by computed-tomographic angiography (CTA), was investigated in this patient group.

METHODS

A total of 374 retrospectively evaluated patients (mean age 78.1 ± 8.4 years, 192 [51.3%] females) who underwent TAVI for severe AS were included. MPA/AOr was measured on preprocedural CTA in all patients and the effect of this measurement on the presence of PH, in-hospital and 2-year-overall long-term mortality was investigated.

RESULTS

The presence of PH was defined as a systolic pulmonary artery pressure (sPAP) >42 mmHg measured by echocardiography. According to multivariate-logistic-regression analysis, MPA/AOr (adjusted [Adj] odds ratio [OR]: 1.188, confidence interval [CI] 95% [1.002-1.410], p = 0.048), tricuspid annular plane systolic excursion (TAPSE) (adj OR:0.736, CI 95% [0.663-0.816], p < 0.001) and left atrial diameter (adj OR:1.051, CI 95% [1.007-1.098], p = 0.024) were identified as independent predictors of PH. In addition, a statistically significant correlation was found between MPA/AOr and TAPSE (r: -0.283, p < 0.001). Furthermore, MPA/AOr was found to be an independent predictor of both in-hospital (adj OR:1.434, CI 95% [1.093-1.881], p = 0.009) and 2-year long-term (adj OR:1.518, CI 95% [1.243-1.853], p < 0.001) mortality in multivariate analysis including TAPSE, STS score and sPAP. In the 2-year Kaplan-Meier survival probability analysis, an MPA/AOr >0.86 was found to have a hazard ratio of 3.697 (95% CI: 2.341-5.840), with a log-rank p < 0.001.

CONCLUSION

MPA/AOr, which can be measured simply by CTA, may be useful as an indicator of the presence of PH and poor prognosis in patients planned for TAVI for severe AS.

Early surgical intervention versus conservative management of asymptomatic severe aortic stenosis: a systematic review and meta-analysis

OBJECTIVE

Timing of intervention for patients with asymptomatic severe aortic stenosis (AS) remains controversial. To compare the outcomes of early aortic valve replacement (AVR) versus watchful waiting (WW) in patients with asymptomatic severe AS.

METHODS

We systematically searched PubMed, Embase and Cochrane databases, in December 2021, for studies comparing early AVR with WW in the treatment of asymptomatic severe AS. Random-effects meta-analysis was performed.

RESULTS

Twelve studies were included in which two were randomised clinical trials. A total of 4130 patients were included, providing a 1092 pooled death events. Our meta-analysis showed a significantly lower all-cause mortality for the early AVR compared with WW group, although with a high amount of heterogeneity between studies in the magnitude of the effect (pooled OR 0.40; 95% CI 0.35 to 0.45, p<0.01; I²=61%). An early surgery strategy displayed a significantly lower cardiovascular mortality (pooled OR 0.33; 95% CI 0.19 to 0.56, p<0.01; I²=64%) and heart failure hospitalisation (pooled OR 0.19; 95% CI 0.10 to 0.39, p<0.01, I²=7%). However, both groups had similar rates of stroke (pooled OR 1.30; 95% CI 0.73 to 2.29, p=0.36, I²=0%) and myocardial infarction (pooled OR 0.49; 95% CI 0.19 to 1.27, p=0.14, I²= 0%).

CONCLUSIONS

This study suggests that for patients with asymptomatic severe AS an early surgical intervention compared with a conservative WW strategy was associated with a lower heart failure hospitalisation and a similar rate of stroke or myocardial infarction, although with significant risk of bias.

PROSPERO REGISTRATION NUMBER

CRD42021291144.

Artificial Intelligence-Enabled Model for Early Detection of Left Ventricular Hypertrophy and Mortality Prediction in Young to Middle-Aged Adults

BACKGROUND

Concealed left ventricular hypertrophy (LVH) is a prevalent condition that is correlated with a substantial risk of cardiovascular events and mortality, especially in young to middle-aged adults. Early identification of LVH is warranted. In this work, we aimed to develop an artificial intelligence (AI)-enabled model for early detection and risk stratification of LVH using 12-lead ECGs.

METHODS

By deep learning techniques on the ECG recordings from 28 745 patients (20-60 years old), the AI model was developed to detect verified LVH from transthoracic echocardiography and evaluated on an independent cohort. Two hundred twenty-five patients from Japan were externally validated. Cardiologists' diagnosis of LVH was based on conventional ECG criteria. The area under the curve (AUC), sensitivity, and specificity were applied to evaluate the model performance. A Cox regression model estimated the independent effects of AI-predicted LVH on cardiovascular or all-cause death.

RESULTS

The AUC of the AI model in diagnosing LVH was 0.89 (sensitivity: 90.3%, specificity: 69.3%), which was significantly better than that of the cardiologists' diagnosis (AUC, 0.64). In the second independent cohort, the diagnostic performance of the AI model was consistent (AUC, 0.86; sensitivity: 85.4%, specificity: 67.0%). After a follow-up of 6 years, AI-predicted LVH was independently associated with higher cardiovascular or all-cause mortality (hazard ratio, 1.91 [1.04-3.49] and 1.54 [1.20-1.97], respectively). The predictive power of the AI model for mortality was consistently valid among patients of different ages, sexes, and comorbidities, including hypertension, diabetes, stroke, heart failure, and myocardial infarction. Last, we also validated the model in the international independent cohort from Japan (AUC, 0.83).

CONCLUSIONS

The AI model improved the detection of LVH and mortality prediction in the young to middle-aged population and represented an attractive tool for risk stratification. Early identification by the AI model gives every chance for timely treatment to reverse adverse outcomes.

Timing of Intervention in Asymptomatic Aortic Stenosis

The decision to perform an intervention for asymptomatic severe aortic stenosis (AS) requires careful weighing of the risks of early intervention against those of watchful observation, and the optimal timing of intervention remains controversial. With improvements in surgical and postoperative care, long-term survival after surgical aortic valve (AV) replacement (AVR) is excellent in low-risk patients, and the emergence of transcatheter AVR may change the thresholds for early preemptive intervention, although a durability issue has to be resolved. A watchful observation strategy also has a risk of sudden death, irreversible myocardial damage, and increase in operative risk while waiting for symptoms to develop. We have been waiting for a prospective randomized trial to solve the intense debate between early AVR and watchful observation, and the RECOVERY (Randomized Comparison of Early Surgery versus Conventional Treatment in Very Severe Aortic Stenosis) trial provides the evidence to support early AVR for asymptomatic severe AS. Risk assessment with severity of AS and staging classification may help to facilitate the identification of patients who may benefit from early intervention. Based on the results of the RECOVERY trial, early surgical AVR is reasonable for asymptomatic patients with very severe AS (aortic jet velocity ≥4.5 m/s) and low surgical risk. Further evidence is required to extend the indications of surgical AVR and to consider transcatheter AVR in asymptomatic patients with severe AS.

Deep Learning Algorithm for Automated Cardiac Murmur Detection via a Digital Stethoscope Platform

Background

Clinicians vary markedly in their ability to detect murmurs during cardiac auscultation and identify the underlying pathological features. Deep learning approaches have shown promise in medicine by transforming collected data into clinically significant information. The objective of this research is to assess the performance of a deep learning algorithm to detect murmurs and clinically significant valvular heart disease using recordings from a commercial digital stethoscope platform.

Methods and Results

Using >34 hours of previously acquired and annotated heart sound recordings, we trained a deep neural network to detect murmurs. To test the algorithm, we enrolled 962 patients in a clinical study and collected recordings at the 4 primary auscultation locations. Ground truth was established using patient echocardiograms and annotations by 3 expert cardiologists. Algorithm performance for detecting murmurs has sensitivity and specificity of 76.3% and 91.4%, respectively. By omitting softer murmurs, those with grade 1 intensity, sensitivity increased to 90.0%. Application of the algorithm at the appropriate anatomic auscultation location detected moderate‐to‐severe or greater aortic stenosis, with sensitivity of 93.2% and specificity of 86.0%, and moderate‐to‐severe or greater mitral regurgitation, with sensitivity of 66.2% and specificity of 94.6%.

Conclusions

The deep learning algorithm’s ability to detect murmurs and clinically significant aortic stenosis and mitral regurgitation is comparable to expert cardiologists based on the annotated subset of our database. The findings suggest that such algorithms would have utility as front‐line clinical support tools to aid clinicians in screening for cardiac murmurs caused by valvular heart disease.

Registration

URL: https://clinicaltrials.gov; Unique Identifier: NCT03458806.

A risk prediction model in asymptomatic patients with severe aortic stenosis: CURRENT-AS risk score

AIMS

Early aortic valve replacement (AVR) might be beneficial in selected high-risk asymptomatic patients with severe aortic stenosis (AS), considering their poor prognosis when managed conservatively. This study aimed to develop and validate a clinical scoring system to predict AS-related events within 1 year after diagnosis in asymptomatic severe AS patients.

METHODS AND RESULTS

We analysed 1274 asymptomatic severe AS patients derived from a retrospective multicentre registry enrolling consecutive patients with severe AS in Japan (CURRENT AS registry), who were managed conservatively and completed 1-year follow-up without AVR. From a randomly assigned derivation set (N = 849), we developed CURRENT AS risk score for the AS-related event (a composite of AS-related death and heart failure hospitalization) within 1 year using a multivariable logistic regression model. The risk score comprised independent risk predictors including left ventricular ejection fraction <60%, haemoglobin ≤11.0 g/dL, chronic lung disease (2 points), diabetes mellitus, haemodialysis, and any concomitant valve disease (1 point). The predictive accuracy of the model was good with the area under the curve of 0.79 and 0.77 in the derivation and validation sets (N = 425). In the validation set, the 1-year incidence of AS-related events was much higher in patients with score ≥2 than in patients with score ≤1 (Score 0: 2.2%, Score 1: 1.9%, Score 2: 13.4%, Score 3: 14.3%, and Score ≥4: 22.7%, P < 0.001).

CONCLUSION

The CURRENT-AS risk score integrating clinical and echocardiographic factors well-predicted the risk of AS-related events at 1 year in asymptomatic patients with severe AS and was validated internally.

Meta-Analysis of Early Intervention Versus Conservative Management for Asymptomatic Severe Aortic Stenosis

The main objective was to determine the optimal strategy for managing asymptomatic severe aortic stenosis between early intervention versus conservative management. We performed a systematic electronic search of the PubMed and Cochrane databases from the inception of the database to May 31, 2020. The Mantel Haenszel method with the Paule-Mandel estimator of Tau² and Hartung-Knapp adjustment were used to calculate relative risk (RR) with a 95% confidence interval (CI) and 95% prediction interval. P curve analysis was used to assess publication bias and estimate the true effect of an intervention. All analysis was carried out using R version 3.6.2. A total of 9 studies were included in the final analysis, consisting of 1,775 patients with early intervention and 3,040 patients with conservative management. Early intervention as compared with conservative management was associated with reduced risk of all-cause mortality (RR 0.36, 95% CI 0.24 to 0.53), cardiac mortality (RR 0.36, 95% CI 0.27 to 0.48) and noncardiac mortality (RR 0.40, 95% CI 0.28 to 0.56). There was no difference in the risk of sudden cardiac death (RR 0.46, 95% CI 0.15 to 1.40), stroke (RR 0.79, 95% CI 0.17 to 3.64), myocardial infarction (RR 0.44, 95% CI 0.01 to 16.82) or heart failure hospitalization (RR 0.18, 95% CI 0.01 to 5.29) with early intervention compared with conservative management. In conclusion, early intervention is associated with reduced all-cause, cardiovascular, and noncardiovascular mortality without increasing any procedure-related clinical outcomes among asymptomatic severe AS patients. Hence, this meta-analysis supports early intervention instead of watchful waiting for the management of asymptomatic severe AS. This systematic review and meta-analysis was registered with PROSPERO- CRD42020188439.

Early Surgery or Conservative Care for Asymptomatic Aortic Stenosis

BACKGROUND

The timing and indications for surgical intervention in asymptomatic patients with severe aortic stenosis remain controversial.

METHODS

In a multicenter trial, we randomly assigned 145 asymptomatic patients with very severe aortic stenosis (defined as an aortic-valve area of ≤0.75 cm² with either an aortic jet velocity of ≥4.5 m per second or a mean transaortic gradient of ≥50 mm Hg) to early surgery or to conservative care according to the recommendations of current guidelines. The primary end point was a composite of death during or within 30 days after surgery (often called operative mortality) or death from cardiovascular causes during the entire follow-up period. The major secondary end point was death from any cause during follow-up.

RESULTS

In the early-surgery group, 69 of 73 patients (95%) underwent surgery within 2 months after randomization, and there was no operative mortality. In an intention-to-treat analysis, a primary end-point event occurred in 1 patient in the early-surgery group (1%) and in 11 of 72 patients in the conservative-care group (15%) (hazard ratio, 0.09; 95% confidence interval [CI], 0.01 to 0.67; P = 0.003). Death from any cause occurred in 5 patients in the early-surgery group (7%) and in 15 patients in the conservative-care group (21%) (hazard ratio, 0.33; 95% CI, 0.12 to 0.90). In the conservative-care group, the cumulative incidence of sudden death was 4% at 4 years and 14% at 8 years.

CONCLUSIONS

Among asymptomatic patients with very severe aortic stenosis, the incidence of the composite of operative mortality or death from cardiovascular causes during the follow-up period was significantly lower among those who underwent early aortic-valve replacement surgery than among those who received conservative care. (Funded by the Korean Institute of Medicine; RECOVERY ClinicalTrials.gov number, NCT01161732.).

Outcomes of Patients With Asymptomatic Aortic Stenosis Followed Up in Heart Valve Clinics

Importance

The natural history and the management of patients with asymptomatic aortic stenosis (AS) have not been fully examined in the current era.

Objective

To determine the clinical outcomes of patients with asymptomatic AS using data from the Heart Valve Clinic International Database.

Design, Setting, and Participants

This registry was assembled by merging data from prospectively gathered institutional databases from 10 heart valve clinics in Europe, Canada, and the United States. Asymptomatic patients with an aortic valve area of 1.5 cm2 or less and preserved left ventricular ejection fraction (LVEF) greater than 50% at entry were considered for the present analysis. Data were collected from January 2001 to December 2014, and data were analyzed from January 2017 to July 2018.

Main Outcomes and Measures

Natural history, need for aortic valve replacement (AVR), and survival of asymptomatic patients with moderate or severe AS at entry followed up in a heart valve clinic. Indications for AVR were based on current guideline recommendations.

Results

Of the 1375 patients included in this analysis, 834 (60.7%) were male, and the mean (SD) age was 71 (13) years. A total of 861 patients (62.6%) had severe AS (aortic valve area less than 1.0 cm2). The mean (SD) overall survival during medical management (mean [SD] follow up, 27 [24] months) was 93% (1%), 86% (2%), and 75% (4%) at 2, 4, and 8 years, respectively. A total of 104 patients (7.6%) died under observation, including 57 patients (54.8%) from cardiovascular causes. The crude rate of sudden death was 0.65% over the duration of the study. A total of 542 patients (39.4%) underwent AVR, including 388 patients (71.6%) with severe AS at study entry and 154 (28.4%) with moderate AS at entry who progressed to severe AS. Those with severe AS at entry who underwent AVR did so at a mean (SD) of 14.4 (16.6) months and a median of 8.7 months. The mean (SD) 2-year and 4-year AVR-free survival rates for asymptomatic patients with severe AS at baseline were 54% (2%) and 32% (3%), respectively. In those undergoing AVR, the 30-day postprocedural mortality was 0.9%. In patients with severe AS at entry, peak aortic jet velocity (greater than 5 m/s) and LVEF (less than 60%) were associated with all-cause and cardiovascular mortality without AVR; these factors were also associated with postprocedural mortality in those patients with severe AS at baseline who underwent AVR (surgical AVR in 310 patients; transcatheter AVR in 78 patients).

Conclusions and Relevance

In patients with asymptomatic AS followed up in heart valve centers, the risk of sudden death is low, and rates of overall survival are similar to those reported from previous series. Patients with severe AS at baseline and peak aortic jet velocity of 5.0 m/s or greater or LVEF less than 60% have increased risks of all-cause and cardiovascular mortality even after AVR. The potential benefit of early intervention should be considered in these high-risk patients.

Stress echocardiography in valvular heart disease

INTRODUCTION

The management of patients with heart valve disease can be complex. Patients may have symptoms disproportionate to the severity or the severity may be unclear. In addition, the optimal timing of intervention in patients with severe disease may be controversial. Areas covered: This article examines the role of stress echocardiography for assessment of patients with low-flow, low-gradient aortic stenosis, asymptomatic severe valve disease and patients where symptoms are discordant to the resting severity of valve disease. Expert commentary: Stress echocardiography helps clinicians determine the true severity of valve disease and may identify the cause of symptoms in patients with only mild/moderate disease. The data provided by stress echocardiography will help determine the appropriate management strategy and the correct timing of intervention.

Sudden Death in Patients With Severe Aortic Stenosis: Observations From the CURRENT AS Registry

Background

The annual incidence of sudden death has been reported to be low (<1%/year) in asymptomatic patients with severe aortic stenosis (AS), and there is a paucity of data on the risk factors of sudden death in patients with severe AS.

Methods and Results

We evaluated the incidence and risk factors of sudden death during the median follow‐up period of 1334 days in the Contemporary Outcomes After Surgery and Medical Treatment in Patients With Severe Aortic Stenosis (CURRENT AS) registry enrolling 3815 consecutive patients with severe AS between 2003 and 2011. The mean age was 78 years, and the prevalences of male sex and prior myocardial infarction were 38% and 8%, respectively. Sudden death occurred in 175 patients without aortic valve replacement. The cumulative 5‐year incidences of sudden death, censored at aortic valve replacement, which accounted for the competing risk, were 9.2% in symptomatic patients and 7.2% (1.4%/year) in asymptomatic patients (P<0.001). Among 82 asymptomatic patients experiencing sudden death, 54 patients (66%) died abruptly without any preceding symptoms, and 35 (65%) of these sudden deaths occurred within 3 months of the last clinical follow‐up visit. Independent risk factors for sudden death were hemodialysis (hazard ratio [HR] 3.63; 95% confidence interval [CI] 2.42‐5.43), prior myocardial infarction (HR 2.11; 95% CI 1.28‐3.50), body mass index <22 (HR 1.51; 95% CI 1.03‐2.21), peak aortic jet velocity ≥5 m/s (HR 1.76; 95% CI 1.12‐2.78), and left ventricular ejection fraction <60% (HR 1.52; 95% CI 1.08‐2.14).

Conclusions

The incidence of sudden death in asymptomatic patients with severe AS might be higher than that reported in previous reports. Several baseline clinical and echocardiographic characteristics were associated with increased risk of sudden death.

Clinical Trial Registration

URL: http://www.umin.ac.jp/ctr/index.htm. Unique identifier: UMIN000012140.

Prognostic value of area of calcified aortic valve by 2-dimensional echocardiography in asymptomatic severe aortic stenosis patients with preserved left ventricular ejection fraction

We hypothesized that area of calcified aortic valve (ACAV) measured by 2D echocardiography (2DE) can predict future cardiovascular events in asymptomatic severe aortic stenosis (AS).Multidetector computed tomography determined aortic valve calcification load is strongly associated with AS severity but has risks for radiation exposure. Quantification of ACAV by transthoracic 2DE is simple and convenient but its clinical utility has not been extensively studied.We measured ACAV in 124 asymptomatic severe AS patients (80 ± 9 years, 45 males) with preserved left ventricular ejection fraction. ACAV was measured by planimetry from 2D zoomed long axis view of the AV at end-diastole. Patients were followed to record cardiac death (CD) and major adverse cardiovascular events (MACEs).During a median follow-up of 232 days, 17 patients had MACE, including 8 CD. ACAV was significantly larger in patients with event compared to those without (1.14 ± 0.35 cm vs 0.87 ± 0.34 cm, P=.0032). Using receiver operating characteristics derived ACAV of 0.79 cm as cutoff value, Kaplan-Meyer analysis showed it could discriminate high-risk group from low-risk group for future CD (P=.0223, χ = 5.22) and MACE (P = .0054, χ = 7.74).2DE determined ACAV is straightforward and has potential to predict future cardiac events in asymptomatic severe AS patients.

Severe Asymptomatic Unicuspid Aortic Stenosis, Myocardial Fibrosis, and Sudden Death: Relevance of Multimodality Imaging

•

Myocardial fibrosis can occur in patients with severe asymptomatic aortic stenosis (AS).

•

Global longitudinal strain and cardiac magnetic resonance can detect myocardial fibrosis in AS.

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Myocardial fibrosis could help to stratify the arrythmic risk of AS patients.

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This could be useful to determine the timing of referral to surgery.

Meta-analysis of the impact of intervention versus symptom-driven management in asymptomatic severe aortic stenosis

OBJECTIVE

The management of patients with asymptomatic, severe aortic stenosis (AS) is controversial. We performed a meta-analysis to examine the impact on outcomes of aortic valve replacement (AVR) in patients with severe asymptomatic AS versus a symptom-driven intervention approach.

METHODS

A search for studies that examined the outcomes of AVR and management of asymptomatic severe AS was performed. We examined the end points of all-cause mortality, cardiac mortality and sudden cardiac death. Our analysis compared early AVR in asymptomatic patients with a symptom-driven AVR approach (excluding symptomatic patients who did not undergo AVR).

RESULTS

Four observational studies were identified with a total of 1300 patients. There was significant heterogeneity between studies (I²=72%). Using a random-effects model, there was a trend towards reduced overall mortality in patients undergoing early AVR compared with a symptom-driven AVR approach (OR 0.54, 95% CI 0.26 to 1.12, p=0.1). There was no significant reduction in cardiac mortality or sudden death (OR 0.78, p=0.85, and OR 0.34, p=0.25, respectively).

CONCLUSIONS

Although there was a trend towards reduced overall mortality when comparing early AVR in patients with asymptomatic, severe AS to a symptom-driven AVR approach, there was no significant difference in cardiac mortality or sudden death. An individual approach focusing on individual risk stratification and operative mortality is required until more robust, randomised trial data are available.

Circulating Endothelial Progenitor Cells and Clinical Outcome in Patients with Aortic Stenosis

Background

Aortic stenosis (AS) is the most common valvular disease. Endothelial progenitor cells (EPCs) have a role in the repair of endothelial surfaces after injury. Reduced numbers of EPCs are associated with endothelial dysfunction and adverse clinical events, suggesting that endothelial injury in the absence of sufficient repair by circulating EPCs promotes the progression of vascular and possibly valvular disorders. The aim of this study was to assess EPC number in patients with AS and to study the predictive value of their circulating levels on prognosis.

Methods

The number of EPCs was determined by flow cytometry in 241 patients with AS and a control group of 73 pts. Thirty-eight, 52 and 151 patients had mild, moderate and severe AS, respectively. We evaluated the association between baseline levels of EPCs and death from cardiovascular causes during follow up.

Results

EPC level was significantly higher in patients with AS compared to the control group (p = 0.017). Two hundred and three patients with moderate and severe AS were followed for a median of 20 months. One hundred and twenty patients underwent an intervention. Thirty four patients died during follow up, 20 patients died due to cardiac causes. Advanced age, the presence of coronary artery disease, AS severity index (combination of high NYHA class, smaller aortic valve area and elevated pulmonary artery pressure) and a low EPC number were predictors of cardiac death in the univariate analysis. Multivariate logistic regression model identified low EPCs number and AS severity index as associated with cardiac death during follow up (p = 0.026 and p = 0.037, respectively).

Conclusions

EPC number is increased in patients with AS. However, in patients with moderate or severe AS a relatively low number of EPCs is associated with cardiac death at follow up. These results may help to identify AS patients at increased cardiovascular risk.

The spectrum of epidemiology underlying sudden cardiac death

Sudden cardiac death (SCD) from cardiac arrest is a major international public health problem accounting for an estimated 15%-20% of all deaths. Although resuscitation rates are generally improving throughout the world, the majority of individuals who experience a sudden cardiac arrest will not survive. SCD most often develops in older adults with acquired structural heart disease, but it also rarely occurs in the young, where it is more commonly because of inherited disorders. Coronary heart disease is known to be the most common pathology underlying SCD, followed by cardiomyopathies, inherited arrhythmia syndromes, and valvular heart disease. During the past 3 decades, declines in SCD rates have not been as steep as for other causes of coronary heart disease deaths, and there is a growing fraction of SCDs not due to coronary heart disease and ventricular arrhythmias, particularly among certain subsets of the population. The growing heterogeneity of the pathologies and mechanisms underlying SCD present major challenges for SCD prevention, which are magnified further by a frequent lack of recognition of the underlying cardiac condition before death. Multifaceted preventative approaches, which address risk factors in seemingly low-risk and known high-risk populations, will be required to decrease the burden of SCD. In this Compendium, we review the wide-ranging spectrum of epidemiology underlying SCD within both the general population and in high-risk subsets with established cardiac disease placing an emphasis on recent global trends, remaining uncertainties, and potential targeted preventive strategies.

Emerging risk biomarkers in cardiovascular diseases and disorders

Present review article highlights various cardiovascular risk prediction biomarkers by incorporating both traditional risk factors to be used as diagnostic markers and recent technologically generated diagnostic and therapeutic markers. This paper explains traditional biomarkers such as lipid profile, glucose, and hormone level and physiological biomarkers based on measurement of levels of important biomolecules such as serum ferritin, triglyceride to HDLp (high density lipoproteins) ratio, lipophorin-cholesterol ratio, lipid-lipophorin ratio, LDL cholesterol level, HDLp and apolipoprotein levels, lipophorins and LTPs ratio, sphingolipids, Omega-3 Index, and ST2 level. In addition, immunohistochemical, oxidative stress, inflammatory, anatomical, imaging, genetic, and therapeutic biomarkers have been explained in detail with their investigational specifications. Many of these biomarkers, alone or in combination, can play important role in prediction of risks, its types, and status of morbidity. As emerging risks are found to be affiliated with minor and microlevel factors and its diagnosis at an earlier stage could find CVD, hence, there is an urgent need of new more authentic, appropriate, and reliable diagnostic and therapeutic markers to confirm disease well in time to start the clinical aid to the patients. Present review aims to discuss new emerging biomarkers that could facilitate more authentic and fast diagnosis of CVDs, HF (heart failures), and various lipid abnormalities and disorders in the future.

Prognostic value of LV deformation parameters using 2D and 3D speckle-tracking echocardiography in asymptomatic patients with severe aortic stenosis and preserved LV ejection fraction

OBJECTIVES

The objective of this study was to determine which strain component assessed by 2-dimensional speckle-tracking echocardiography (2DSTE) and 3-dimensional speckle-tracking echocardiography (3DSTE) was the most powerful predictor for future major adverse cardiac events (MACE) in asymptomatic patients with severe aortic stenosis (AS).

BACKGROUND

Ongoing debate exists regarding the appropriateness of early surgery in asymptomatic severe AS and preserved left ventricular ejection fraction (LVEF). Previous studies showed that 2-dimensional global longitudinal strain (2DGLS) was a significant predictor in asymptomatic severe AS patients. However, the prognostic utility of 3DSTE-derived multidirectional strain parameters has not been investigated in these patients.

METHODS

We enrolled 104 asymptomatic severe AS patients (indexed aortic valve area <0.6 cm(2)/m(2)) and preserved LVEF and performed strain analysis using both 2DSTE and 3DSTE. Two-dimensional and 3-dimensional global longitudinal, circumferential, and radial strain and global 3-dimensional strain were measured in each patient. All patients were followed to record MACE.

RESULTS

During a median follow-up of 373 days, MACE developed in 33 patients (32%). 2DGLS (-14.7 ± 3.3 vs. -16.3 ± 3.3, p = 0.0168), 3DGLS (-13.5 ± 2.5 vs. -16.1 ± 2.4, p < 0.0001) and 3-dimensional global radial strain (3DGRS) (35.9 ± 4.5 vs. 38.1 ± 4.4, p = 0.0209) were significantly impaired in patients with MACE compared with those without MACE. Kaplan-Meier analysis showed 2DGLS (cutoff: -17.0%), 3DGLS (cutoff: -14.5%), and 3DGRS (cutoff: 39.0%) provide a significant difference in MACE rate. Receiver-operating characteristic analysis revealed that the area under the curve of 3DGLS for MACE (0.78) was significantly larger than that of 2DGLS (0.62, p = 0.0044) and 3DGRS (0.66, p = 0.0069). Separate multivariate analysis revealed 3DGLS was only significant as independent predictor for future MACE after correcting for mean pressure gradient and left ventricular mass index.

CONCLUSIONS

3DGLS is the most robust index for predicting future adverse cardiac events in asymptomatic severe AS patients with preserved LVEF.

[Asymptomatic severe aortic stenosis: a reopened debate]

Aortic stenosis is a complex disease. About 2-7% of the population over 65 years of age is affected by its degenerative form. In patients with severe aortic stenosis presenting with symptoms or left ventricle ejection fraction (LVEF)<.50, aortic valve replacement is indicated. Management and timing of surgery in asymptomatic patients with preserved LVEF is still a matter of debate. Recent published data show that about one third of these patients present with low left ventricle stroke volume, which may affect survival. For this reason, and considering that aortic valve replacement is in most cases a low risk procedure, early surgery in this subgroup is a strategy that deserves to be taken into account. In this review we report on these recent findings, which allow understanding why patients with asymptomatic severe aortic stenosis should not be considered and treated as a homogenous population.

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.