Prognostic Value of Left Atrial Strain in Aortic Stenosis: A Competing Risk Analysis.

BACKGROUND: The role of left atrial (LA) strain as an imaging biomarker in aortic stenosis is not well established. The aim of this study was to investigate the prognostic performance of phasic LA strain in relation to clinical and echocardiographic variables and N-terminal pro-B-type natriuretic peptide in asymptomatic and minimally symptomatic patients with moderate to severe aortic stenosis and left ventricular ejection fraction > 50%. METHODS: LA reservoir strain (LASr), LA conduit strain (LAScd), and LA contractile strain (LASct) were measured using speckle-tracking echocardiography. The primary outcome was a composite of all-cause mortality, heart failure hospitalization, progression to New York Heart Association functional class III or IV, acute coronary syndrome, or syncope. Secondary outcomes 1 and 2 comprised the same end points but excluded acute coronary syndrome and additionally syncope, respectively. The prognostic performance of phasic LA strain cutoffs was evaluated in competing risk analyses, aortic valve replacement being the competing risk. RESULTS: Among 173 patients (mean age, 69 ± 11 years; mean peak transaortic velocity, 4.0 ± 0.8 m/sec), median LASr, LAScd, and LASct were 27% (interquartile range [IQR], 22%-32%), 12% (IQR, 8%-15%), and 16% (IQR, 13%-18%), respectively. Over a median of 2.7 years (IQR, 1.4-4.6 years), the primary outcome and secondary outcomes 1 and 2 occurred in 66 (38%), 62 (36%), and 59 (34%) patients, respectively. LASr < 20%, LAScd < 6%, and LASct < 12% were identified as optimal cutoffs of the primary outcome. In competing risk analyses, progressing from echocardiographic to echocardiographic-clinical and combined models incorporating N-terminal pro-B-type natriuretic peptide, LA strain parameters outperformed other key echocardiographic variables and significantly predicted clinical outcomes. LASr < 20% was associated with the primary outcome and secondary outcome 1, LAScd < 6% with all clinical outcomes, and LASct < 12% with secondary outcome 2. LAScd < 6% had the highest specificity (95%) and positive predictive value (82%) for the primary outcome, and competing risk models incorporating LAScd < 6% had the best discriminative value. CONCLUSIONS: In well-compensated patients with moderate to severe aortic stenosis and preserved left ventricular ejection fractions, LA strain was superior to other echocardiographic indices and incremental to N-terminal pro-B-type natriuretic peptide for risk stratification. LAScd < 6%, LASr < 20%, and LASct < 12% identified patients at higher risk for adverse outcomes.

Transcatheter aortic valve replacement for aortic regurgitation in Asians: TAVR for aortic regurgitation in Asians.

AIMS: Although surgical aortic valve replacement (SAVR) is currently the recommended intervention for patients with native AR without aortic stenosis, a significant proportion of Asian patients undergo transcatheter aortic valve replacement (TAVR), which has not been studied fully for safety and outcomes. This systematic review aims to examine the characteristics and outcomes of Asian patients with pure native aortic regurgitation (AR) undergoing TAVR. METHODS AND RESULTS: PubMed, Embase, Scopus, Web of Science and Cochrane CENTRAL were systematically searched for randomised controlled trials, observational studies and case reports published  from inception to 2 April 2020, involving patients of Asian ethnicity with pure native aortic regurgitation who had undergone TAVR. Our primary outcome was all-cause mortality, with secondary outcomes including all major complications. Five studies (n=274 patients) and eight case reports were included. Device success was reported in 94.9% of the patients, the all-cause mortality rate was 4.4%, 2.5% were converted to SAVR, 1.7% had post-operative paravalvular leak and 6.7% required permanent pacemaker implantation. CONCLUSIONS: TAVR has demonstrated acceptable safety and efficacy in Asian patients with pure AR displaying low mortality rates and few adverse outcomes.

Inadequately low left ventricular mass in patients with significant aortic stenosis predicts favourable prognostic outcomes.

In patients with significant aortic stenosis (AS), the prognostic effect of the increase in left ventricular mass (LVM) in relation to one's hemodynamic load has been described. Inappropriately high LVM has been shown to predict adverse cardiovascular events. However, little is known about the prognostic impact of inadequately low LVM (i-lowLVM) in patients with significant AS. I-lowLVM was defined as the measured LVM < 73% of the predicted LVM based on sex, stroke work and height from the reference adult population, used in previous established studies. For outcome analysis, the end-point was defined as all-cause mortality, aortic valve replacement and/or admission for congestive heart failure. Kaplan-Meier curves and multivariable Cox regression models were constructed to compare outcomes on follow-up. During the follow-up (4.5 ± 4.1 years), 132 patients (11.1%) had i-lowLVM, 868 (73.1%) had adequate-LVM, 188 (15.8%) had inappropriately high LVM. Outcome analysis only included patients with i-lowLVM and adequate-LVM (N = 1000). An adverse composite event occurred in 41.7% of the i-lowLVM group and 52.4% of the adequate-LVM group (p = 0.021). Event-free survival in patients with i-lowLVM and appropriate-LVM was 76% versus 68% at 2-year, 55% versus 46% at 4-year, 33% versus 27% at 6-year, 20% versus 17% at 8-year, and 17% versus 11% at 10-year follow-up, respectively (p < 0.001). Cox analysis revealed that i-lowLVM was independently associated with lower composite adverse outcome (HR 0.624, 95% CI 0.460-0.846, p = 0.002) after adjusting for sex, age, ejection fraction, ischemic heart disease, diabetes and transaortic valve mean gradient. In the separate Cox subanalyses, the presence of i-lowLVM remained a predictor of lower composite adverse outcome in the severe AS subgroup (HR 0.587, 95% CI 0.396-0.870, p = 0.008), and the LVH subgroup (HR 0.574, 95% CI 0.401-0.824, p = 0.003) after adjusting for confounders. I-lowLVM despite significant AS may represent a distinct group that is associated with improved survival outcomes independent of other prognostic covariates.

Differences in Clinical and Echocardiographic Profiles and Outcomes of Patients With Atrial Fibrillation Versus Sinus Rhythm in Medically Managed Severe Aortic Stenosis and Preserved Left Ventricular Ejection Fraction.

BACKGROUND: Atrial fibrillation (AF) results in the loss of atrial booster pump function and portends poorer outcome in aortic valve stenosis (AS). However, its characteristics and impact on medically managed AS remained under-recognised. We compared these patients with AF to sinus rhythm (SR). METHOD: In total, 347 consecutive patients with medically managed severe AS (aortic valve area <1 cm2) and preserved left ventricular ejection fraction (>50%) were studied, in terms of echocardiographic characteristics and clinical outcomes. Appropriate univariate and multivariate models were used, while Kaplan-Meier curves and Cox regression models were constructed to compare clinical outcomes (mortality, admissions for congestive cardiac failure, and stroke). RESULTS: Ninety (90) (25.9%) patients had AF. Patients with AF had lower body mass index (BMI 18.5±10.4 vs 23.8±6.2 g/m2; p<0.001), larger left ventricular mass index (LVMI 127.9±39.0 vs 116.7±36.5; p=0.017), and left atrial volume index (53.2±20.0 vs 31.0±9.2 mL/m2; p=0.004). Atrial fibrillation was associated with higher mortality (52.2% vs 37.4%; Kaplan-Meier log-rank 7.18; p=0.007), admissions for congestive cardiac failure (log-rank 6.42; p=0.011), and poorer composite outcomes (log-rank 6.29; p=0.012). The incidence of stroke in both groups were similar on follow-up (log-rank 0.08; p=0.776). After adjusting for age, BMI, LVMI, and left atrial volume index on Cox regression, AF remained independently associated with poorer composite clinical outcomes (hazard ratio, 1.66; 95% confidence interval 1.07-2.58). CONCLUSIONS: Atrial fibrillation remained an important comorbidity affecting a quarter of patients with medically managed severe AS. It was independently associated with poorer clinical outcomes and may thus aid in prognostication and management.

Echocardiographic discrepancies in severity grading of aortic valve stenosis with left ventricular outflow tract (LVOT) cut-off values in an Asian population.

Inconsistencies in grading of aortic stenosis (AS) severity have been reported. However, it remains to be studied in an Asian population. We investigated consistency of grading AS severity at various left ventricular outflow tract diameter (LVOTd) categories, and postulated alternative cut-offs for more consistent grading of AS severity. Consecutive Asian patients (n = 350) with index echocardiographic diagnosis of severe AS were divided them into three groups based on LVOTd: 'small' (< 20 mm), 'average' (20-22 mm) and 'large' (> 22 mm). In each group, the consistency of flow-dependent (transaortic mean pressure gradient (MG)) and flow-independent parameters (AVA) were used for classification of AS severity. Of 350 patients, 51.7% had small LVOTd, while 30.8% and 17.5% had average and large LVOTd respectively. Consistent grading by LVOTd based on AVA and MG, was seen in 33.7% of patients with small, 47.6% with average, 57.7% with large LVOTd. When an AVA cut-off of 0.9 cm2 was used, consistent grading improved to 38.0% in small, 56.5% in average and 70.0% in large LVOTd. At an AVA cut-off of 0.8 cm2, there was further incremental improvement in the small LVOTd group to 54.1% (p < 0.05). In conclusion, current severe AS guidelines are most inconsistent with those in the small LVOTd group. With majority of the study's Asian population having small LVOTd, this raises concerns that current AS guidelines may overestimate the severity of AS in the Asian cohort. Improved consistency in echocardiographic grading may be attained with a lower AVA cut-off in this Asian cohort.

Synchronous cardiocerebral infarction in the era of endovascular therapy: which to treat first?

A cardiocerebral ischemic attack (CCI) or a concurrent acute ischemic stroke (AIS) and myocardial infarction (AMI) is a severe event with no clear recommendations for ideal management because of the rarity of the scenario. The narrow time window for treatment and complexity of the treatment decision puts immense pressure on the treating physician. We evaluated this challenging situation at our tertiary center. Using our prospective stroke database out of a total of 555 patients with acute ischemic stroke between 2009 and 2014, we identified five consecutive cases with CCI (incidence 0.009%). Demography, risk factor characteristics, vascular occlusions and treatment approach were recorded. Good functional outcome was defined by the modified Rankin scale (mRS) score of 0-2 points. Out of five patients, AIS was treated with endovascular treatment in three cases, while two were treated with intravenous thrombolysis only. One out of three patients had embolectomy of the brain performed prior to the coronary intervention, while the other two patients underwent coronary intervention first. One patient developed sudden cardiac arrest on day-2 and passed away. CCI is an uncommon and devastating clinical scenario, further research is needed for the ideal management strategy that provides the best outcomes. However, the rarity of the disease does not lend itself to the conduct of a trial easily. We have proposed a considered treatment algorithm based on the current literature and our experience.

Constrictive Pericarditis Following Correction of Partial Anomalous Pulmonary Venous Drainage.

We report the case of a 23-year-old man who developed constrictive pericarditis within four months after pulmonary valve replacement and repair of partial anomalous pulmonary venous connection. He had previously undergone repair of tetralogy of Fallot in infancy. After an unsuccessful trial of medical management for persistent right heart failure, magnetic resonance imaging was done, which showed a thickened pericardium. He underwent a radical pericardiectomy with a good outcome. The case is presented to illustrate a less well-recognized cause of cardiac failure following congenital cardiac surgery, which may otherwise be attributed to the failure of surgery or residual complications.

How temporal evolution of intracranial collaterals in acute stroke affects clinical outcomes.

OBJECTIVE: We compared intracranial collaterals on pretreatment and day 2 brain CT angiograms (CTA) to assess their evolution and relationship with functional outcomes in acute ischemic stroke (AIS) patients treated with IV tissue plasminogen activator (tPA). METHODS: Consecutive AIS patients who underwent pretreatment and day 2 CTA and received IV tPA during 2010-2013 were included. Collaterals were evaluated by 2 independent neuroradiologists using 3 predefined criteria: the Miteff system, the Maas system, and 20-point collateral scale by the Alberta Stroke Program Early CT Score methodology. We stratified our cohort by baseline pre-tPA state of their collaterals and by recanalization status of the primary vessel for analysis. Good outcomes at 3 months were defined by a modified Rankin Scale score of 0-1. RESULTS: This study included 209 patients. Delayed collateral recruitment by any grading system was not associated with good outcomes. All 3 scoring systems showed that collateral recruitment on the follow-up CTA from a baseline poor collateral state was significantly associated with poor outcome and increased bleeding risk. When the primary vessel remained persistently occluded, collateral recruitment was significantly associated with worse outcomes. Interestingly, collateral recruitment was significantly associated with increased mortality in 2 of the 3 grading systems. CONCLUSIONS: Not all collateral recruitment is beneficial; delayed collateral recruitment may be different from early recruitment and can result in worse outcomes and higher mortality. Prethrombolysis collateral status and recanalization are determinants of how intracranial collateral evolution affects functional outcomes.

Redo MitraClip mitral valve repair after a late single leaflet detachment.

Percutaneous mitral valve repair with the MitraClip® (Abbott, Abbott Park, IL) can reduce mitral regurgitation (MR) and improve symptoms and quality of life in patients with severe mitral regurgitation. While this therapy is safe, there have been reports of single leaflet detachment where the MitraClip remains attached only to one leaflet of the mitral valve after deployment. Most of these cases occur within the first month of the procedure but there have been reports of late detachment occurring after this period. This case report describes a patient with severe functional MR who underwent an initial successful MitraClip procedure with implantation of two clips but subsequently developed late detachment of one clip. It also discusses the challenges and feasibility of performing a repeat MitraClip procedure in these patients.

Demographics of severe valvular aortic stenosis in Singapore.

INTRODUCTION: The treatment of aortic valve stenosis (AS) is seeing renewed interest mainly due to the availability of transcatheter therapies. However, the number of epidemiological studies of this disease in Singapore is limited. We aimed to describe the aetiology and clinical presentation of AS in Singapore, as well as patients' attitudes toward it. Our findings may facilitate the future planning and utilisation of resources to better manage these patients. METHODS: 249 consecutive patients who underwent transthoracic echocardiography (from April 1999 to April 2008) and diagnosed with severe AS were assessed. Demographic and clinical data were collected, and patients' decisions on surgery were determined. RESULTS: The mean patient age was 71 (range 23-98) years. 50.2% of patients were male. The commonest presenting symptom was dyspnoea, and 40 (16.0%) patients had coexistent atrial fibrillation. The aetiology of AS was degenerative in 216 (86.7%), rheumatic in 11 (4.4%) and related to a bicuspid valve in 22 (8.9%) patients. The average peak velocity across the aortic valve was 4.2 ± 0.8 m/s and the mean aortic valve area was 0.76 ± 0.13 cm2. The overall mean logistic EuroSCORE was 10.7 ± 12.3. 105 (42.2%) patients who were offered surgery refused. 87 (35%) deaths were seen during the follow-up period (mean duration 14.5 months), which also saw 68 (27%) patients undergo surgery and 86 (34%) patients hospitalised for heart failure. CONCLUSION: Degenerative AS was the commonest aetiology in this contemporary cohort of patients. Despite the known benefits of surgery, the refusal rate for surgery remained high.

Challenges in the management of aortic coarctation in the elderly: native coarctation complicated by severe calcification.

Although the treatment of aortic coarctation in adults with the use of stents has shown favourable results and reduced complications, there have been few studies involving elderly patients. We highlight the clinical challenges faced in the management of such patients, with attention to severe calcification at the coarctation site. The midterm results were good in our patient, showing an improvement in blood pressure control and maintenance of stent patency.

Total isovolumic time relates to exercise capacity in patients with transposition of the great arteries late after atrial switch procedures.

BACKGROUND: Systemic right ventricular systolic dysfunction is common late after atrial switch surgery for transposition of the great arteries. Total isovolumic time is the time that the ventricle is neither ejecting nor filling and is calculated without relying on geometric assumptions. We assessed resting total isovolumic time in this population and its relationship to exercise capacity. METHODS: A total of 40 adult patients with transposition of the great arteries after atrial switch - and 10 healthy controls - underwent transthoracic echocardiography and cardiopulmonary exercise testing from January, 2006 to January, 2009. Resting total isovolumic time was measured in seconds per minute: 60 minus total ejection time plus total filling time. RESULTS: The mean age was 31.6 plus or minus 7.6 years, and 38.0% were men. There were 16 patients (40%) who had more than or equal to moderate systolic dysfunction of the right ventricle. Intra- and inter-observer agreement was good for total isovolumic time, which was significantly prolonged in patients compared with controls (12.0 plus or minus 3.9 seconds per minute versus 6.0 plus or minus 1.8 seconds per minute, p-value less than 0.001) and correlated significantly with peak oxygen consumption (r equals minus 0.63, p-value less than 0.001). The correlation strengthened (r equals minus 0.73, p-value less than 0.001) after excluding seven patients with exercise-induced cyanosis. No relationship was found between exercise capacity and right ventricular ejection fraction or long-axis amplitude. CONCLUSION: Resting isovolumic time is prolonged after atrial switch for patients with transposition of the great arteries. It is highly reproducible and relates well to exercise capacity.

Comprehensive use of cardiopulmonary exercise testing identifies adults with congenital heart disease at increased mortality risk in the medium term.

BACKGROUND: Parameters of cardiopulmonary exercise testing were recently identified as strong predictors of mortality in adults with congenital heart disease. We hypothesized that combinations of cardiopulmonary exercise testing parameters may provide optimal prognostic information on midterm survival in this population. METHODS AND RESULTS: A total of 1375 consecutive adult patients with congenital heart disease (age, 33±13 years) underwent cardiopulmonary exercise testing at a single center over a period of 10 years. Peak oxygen consumption (peak V(O(2))), ventilation per unit of carbon dioxide production (V(E)/V(O(2)) slope), and heart rate reserve were measured. During a median follow-up of 5.8 years, 117 patients died. Peak V(O(2)), heart rate reserve, and V(E)/V(O(2)) slope were related to midterm survival in adult patients with congenital heart disease. Risk of death increased with lower peak V(O(2)) and heart rate reserve. A higher V(E)/V(O(2)) slope was also related to increased risk of death in noncyanotic patients, whereas the V(E)/V(O(2)) slope was not predictive of mortality in cyanotic patients. The combination of peak V(O(2)) and heart rate reserve provided the greatest predictive information after adjustment for clinical parameters such as negative chronotropic agents, age, and presence of cyanosis. However, the incremental value of these exercise parameters was reduced in patients with peak respiratory exchange ratio <1.0. CONCLUSIONS: Cardiopulmonary exercise testing provides strong prognostic information in adult patients with congenital heart disease. Prognostication should be approached differently, depending on the presence of cyanosis, use of rate-lowering medications, and achieved level of exercise. We provide 5-year survival prospects based on cardiopulmonary exercise testing parameters in this growing population.

A high-risk period for cerebrovascular events exists after transcatheter aortic valve implantation.

OBJECTIVES: This study assesses if there exists a high-risk period for cerebrovascular events (CeV) after transcatheter aortic valve implantation (TAVI). BACKGROUND: Even though acute strokes after TAVI have been described, it is uncertain if stroke rates continue to remain high in the early months after TAVI. Furthermore, the optimal dose and duration of thromboprophylaxis is unclear. METHODS: Patients who underwent TAVI were evaluated at baseline, at discharge, at 1 and 6 months, and yearly. Risk factors for CeV events, procedural details, and antithrombotic therapy were recorded. Outcomes assessed were CeV events and death. The timing of such events, predictors, and impact on survival were analyzed. RESULTS: A total of 253 patients were assessed. Median age was 85 years. The median Society of Thoracic Surgeons score was 8.1% (interquartile range [IQR]: 5.5% to 12.0%). Risk factors included smoking (47%), hypertension (70%), dyslipidemia (66%), and diabetes mellitus (25%). Twenty-three percent had known cerebrovascular disease and 39% had atrial fibrillation. Median follow-up was 455 days (IQR: 160 to 912 days) at which time 23 patients experienced a CeV event. The incidence was highest in the first 24 h but remained high for 2 months. In-hospital mortality rate after a CeV event was 21%. A prior history of CeV disease was an independent predictor of an event (hazard ratio: 4.23, 95% CI: 1.60 to 11.11, p = 0.004). CONCLUSIONS: The incidence of CeV events is highest within 24 h of TAVI, but this risk may remain elevated for up to 2 months. A prior history of cerebrovascular disease is an independent predictor. This may have implications for patient selection and antithrombotic strategies.