Valvular Aortic Stenosis Research Articles

Outcome of Patients Undergoing Transcatheter Implantation of Aortic Valve With Previous Mitral Valve Prosthesis (OPTIMAL) Study

BackgroundTranscatheter aortic valve replacement (TAVR) is the gold standard for severe valvular aortic stenosis in patients at high/prohibitive surgical risk. This procedure has also been used in patients with previous mitral valve (MV) prostheses, with contrasting outcomes reported. The aim of this study is to describe procedural and early outcomes of patients with previous MV prostheses undergoing TAVR. MethodsThis is a retrospective registry of 154 patients with previous MV prostheses who underwent TAVR across high-volume medical centres at a mean of 11.7 ± 8.4 years after mitral surgery. ResultsMean mitroaortic distance at computed tomography was 9.7 ± 4.8 mm. Procedural success was achieved in 150 (97.4%) patients, with reduction of aortic gradients (42.6 ± 14.2 to 10.0 ± 7.0 mm Hg; P < 0.001). Device success was achieved in 133 (86.3%) patients. MV prosthesis interference by the TAVR device was observed in 2 patients; in both, the mitroaortic distance was <5 mm, with 1 complicated by TAVR prosthesis embolization. Periprocedural complications included 4 (2.6%) cerebrovascular accidents, 10 (6.6%) major vascular complications, 22 (14.4%) severe bleedings, 1 (0.7%) myocardial infarction, and 5 (3.2%) in-hospital deaths (all cases cardiovascular or procedure related). At a median follow-up of 13.5 (interquartile range 1.0 to 36.0) months, 26 (16.9%) deaths occurred; 15 (9.7%) were cardiac related. Late fatal mitral prosthesis thromboses occurred in 2 patients. We recorded a case of fatal hemorrhagic stroke; hospital readmission was observed in 25 (16.2%) patients due to worsening heart failure. ConclusionsTAVR in patients with previous mitral prostheses appears to be safe and feasible, with good hemodynamic results at 30-day and at longer-term follow-up.

Left ventricular ejection hemodynamics before and after relief of outflow tract obstruction in patients with hypertrophic obstructive cardiomyopathy and valvular aortic stenosis

ObjectiveThere has been debate on the importance and pathophysiologic effects of the dynamic subaortic pressure gradient in hypertrophic obstructive cardiomyopathy. The study was conducted to elucidate the hemodynamic abnormalities associated with the dynamic pressure gradient in hypertrophic obstructive cardiomyopathy. MethodsEight patients with hypertrophic obstructive cardiomyopathy and 7 patients with valvular aortic stenosis underwent a detailed hemodynamic study of pressure flow relationships before and after myectomy or aortic valve replacement during operation. ResultsIn aortic stenosis, the increased gradient after premature ventricular contraction was associated with an increase in peak flow (325 ± 122 mL/s to 428 ± 147 mL/s, P = .002) and stroke volume (75.0 ± 27.3 mL to 88.0 ± 24.0 mL, P = .004), but in hypertrophic obstructive cardiomyopathy peak flow remained unchanged (289 ± 79 mL/s to 299 ± 85 mL/s, P = .334) and stroke volume decreased (45.9 ± 18.7 mL to 38.4 ± 14.4 mL, P = .04) on the postpremature ventricular contraction beat. After myectomy, the capacity to augment stroke volume on the postpremature ventricular contraction beats was restored in patients with hypertrophic obstructive cardiomyopathy (45.6 ± 14.4 mL to 54.4 ± 11.8 mL, P = .002). ConclusionsThe pressure flow relationship in hypertrophic obstructive cardiomyopathy supports the concept of true obstruction to outflow, with a low but continued flow during late systole, when the ventricular-aortic pressure gradient is the highest. Septal myectomy can abolish obstruction and restore the ability to augment stroke volume, which may explain the mechanism of symptomatic improvement after operation.

Identification and Progression of Aortic Valve Regurgitation in the db/db Mouse Model of Type 2 Diabetes Mellitus

Cardiovascular complications, including heart failure, coronary microvascular disease and valvular disease, are leading causes of mortality in patients with type 2 diabetes mellitus (T2DM). Importantly, there is a strong correlation between patients with T2DM and aortic valve disease (AVD), such as calcified aortic valve, valvular stenosis, or regurgitation. Therefore, the goal of this study was to evaluate the hypothesis that db/db mice with T2DM exhibited some manifestations of valve disease. To investigate this, we examined cardiac structure and function of db/db mice at two time points to determine the presence and extent of AVD. Heterozygous Db/db (control) and homozygous db/db (T2DM) mice were subjected to echocardiography at 16 and 24 weeks of age. At 16 weeks of age 30% of db/db mice (3 of 10) presented with aortic regurgitation compared to 0% of the controls (0 of 9). By 24 weeks of age, 48% of db/db mice (15 of 31) developed aortic regurgitation compared to 15% of controls (4 of 26). At this same time‐point, 32% of db/db mice (10 of 31) showed peak aortic velocities above 1600 mm/s, suggesting a stenotic phenotype, while the incidence was only 15% for controls (4 of 26). Left ventricular end‐diastolic volumes (LVEDVs) were decreased in db/db mice at both 16‐ and 24 weeks compared to controls (16 wks: control 75.1 μl ± 1.9 vs db/db 61.1 μl ± 1.9: p&lt;0.0001; 24 wks: control 82.1 μl ± 2.2 vs db/db 69.1 μl ± 1.6; p=0.0008). However, db/db mice with regurgitant valves had an increased LVEDV and stroke volume (SV) compared with those that did not (24 wks: LVEDV 74.7 μl ± 1.9 vs 63.4 μl ± 1.9 respectively; p=0.06. SV: 49.9 ml ± 1.3 vs 40.9 ml ± 1.5 respectively; P=0.01). Furthermore, there were significant increases in LVEDV (61.1 μl ± 1.8 to 69.1 μl ± 1.6; p=0.03) and stroke volume (SV: 38.8 ml ± 1.1 to 45.3 ml ± 1.2; p=0.004) of db/db mice from 16 weeks to 24 weeks. Interestingly, as the db/db mice age, there was a significant decrease in body weight from 16 weeks to 24 weeks (51.1 g ± 0.5 to 44.7 g ± 1.3 respectively; P&lt;0.0001). However, further analysis shows that this difference is driven by db/db mice exhibiting a regurgitant phenotype, which weighed significantly less than the db/db mice with normal flow (40.6 g ± 1.56to 48.6 g ± 1.7 respectively; P=0.0002). T2DM mice with normal flow exhibited no difference in body weight with age (16 vs 24 weeks; p&gt;0.99). Finally, E/A ratio was significantly higher for db/db mice at both 16 weeks (1.77 ± 0.04 vs 1.53 ± 0.03; p&lt;0.0001) and 24 weeks (1.84 ± 0.05 vs 1.59 ± 0.04; p=0.009). These data show the presence of aortic valve regurgitation in a small subset of db/db mice that, interestingly, correlated with a reduction in body weight over time. The db/db mouse T2DM model exhibits features of diastolic dysfunction as evidenced by reduced LVEDV compare to control; however, db/db mice that had regurgitation showed an expected elevation in LVEDV and SV. Taken together, our data suggest that db/db mice can develop AVD that coincides with diastolic dysfunction. Further studies are needed to investigate the underlying mechanism that leads to the development of the AVD phenotype in db/db mice.Support or Funding InformationSupport: NIH R00 HL116769, NIH R21 EB026518, and NCH to AJTThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Grading Aortic Valve Stenosis With Dimensionless Index During Pre-cardiopulmonary Bypass Transesophageal Echocardiography: A Comparison With Transthoracic Echocardiography

The authors hypothesized that grading valvular aortic stenosis (AS) with dimensionless index (DI) during intraoperative pre-cardiopulmonary bypass (pre-CPB) transesophageal echocardiography (TEE) would match the grade of AS during preoperative transthoracic echocardiography (TTE) for the same patients more often than when using peak velocity (Vp), mean pressure gradient (PGm), or aortic valve area (AVA). Retrospective, observational. Single university hospital. The participants in this study included 123 cardiac surgical patients with any degree of AS, who underwent open cardiac surgery between 2010 and 2016 at the Medical University of South Carolina and had Vp, PGm, AVA, and DI values available from reporting databases or archived imaging. None. When using DI, pre-CPB TEE grading of AS severity was 1 grade higher 21.1% of the time and 1 grade lower 13.0% of the time compared with TTE, for an overall disagreement rate of 34.1%. The overall disagreement rates between pre-CPB TEE and TTE for Vp, PGm, and AVA were 39.8%, 33.3%, and 33.3%, respectively. The authors could not demonstrate that DI was better than Vp, PGm, or AVA at matching AS grades between intraoperative pre-CPB TEE and preoperative TTE. When DI was used, pre-CPB TEE was more likely to overestimate than underestimate the severity of AS compared with TTE. However, when Vp or PGm was used, pre-CPB TEE was more likely to underestimate the severity of AS compared with TTE. A comprehensive approach without overemphasis on 1 parameter should be used for AS assessment by intraoperative TEE.

Epidemiology of stroke and cerebral protection in patients undergoing transcatheter aortic valve replacement

The introduction into clinical practice of transcatheter aortic valve implantation (TAVI) has led to a significant change in the therapeutic paradigm for patients with valvular aortic stenosis. However, in parallel with the benefits obtained in prognosis and quality of life, an inherent risk of major cerebral thromboembolic events has been observed. In different studies this risk has been estimated between 2% and 6%. In order to reduce the incidence of cerebrovascular accidents during TAVI, several brain protection systems have been developed but, to date, none has obtained sufficient clinical evidence to be implemented on a large scale, and they are therefore used only in selected cases. Furthermore, periprocedural drug therapy and follow-up are still the subject of extensive discussion in the scientific community. This paper reviews the topic of stroke prevention in patients undergoing TAVI for both the periprocedural and postprocedural aspects.

Congenital Cardiac Outflow Tract Abnormalities in Dogs: Prevalence and Pattern of Inheritance From 2008 to 2017.

Subvalvular aortic stenosis (SAS) and valvular pulmonic stenosis (PS) are two of the most common congenital heart diseases of dogs. The aim of this study was to determine the prevalence and mode of inheritance of these congenital heart diseases in a large veterinary teaching hospital population. Case records of dogs presented to the University of California Davis, Veterinary Medical Teaching Hospital (UCD VMTH) between January 2008 to December 2017 were reviewed retrospectively and pedigree information was obtained when available. There were 259 unique SAS and 336 unique PS cases diagnosed during the study period. The prevalence of SAS was 0.3% of overall hospital admissions and 4.7% for all dogs seen by the cardiology service. The prevalence for PS was 0.41% of overall hospital admissions and 6.1% of dogs seen by the cardiology service. Bullmastiffs and Newfoundlands had the greatest prevalence (6.59 and 4.46%, respectively) and odds ratio (52.43 and 34.73, respectively) for SAS. Bulldogs and French Bulldogs had the greatest prevalence (4.8 and 2.7%, respectively) and odds ratio (13.32 and 7.52, respectively) for PS. The identified prevalence of SAS and PS is higher than previously reported. Pedigree analysis in SAS affected Bullmastiffs, Golden Retrievers, and Rottweilers suggested an autosomal recessive pattern of inheritance. The mode of inheritance for PS in Bulldogs, also appears to be autosomal recessive. The results of this study can be used to inform future selection of breeding pairs and genetic studies aimed at reducing the prevalence of these common congenital heart diseases.

Acute Q Fever Endocarditis: A Paradigm Shift Following the Systematic Use of Transthoracic Echocardiography During Acute Q Fever.

As Q fever, caused by Coxiella burnetii, is a major health challenge due to its cardiovascular complications, we aimed to detect acute Q fever valvular injury to improve therapeutic management. In the French national reference center for Q fever, we prospectively collected data from patients with acute Q fever and valvular injury. We identified a new clinical entity, acute Q fever endocarditis, defined as valvular lesion potentially caused by C. burnetii: vegetation, valvular nodular thickening, rupture of chorda tendinae, and valve or chorda tendinae thickness. To determine whether or not the disease was superimposed on an underlying valvulopathy, patients' physicians were contacted. Aortic bicuspidy, valvular stenosis, and insufficiency were considered as underlying valvulopathies. Of the 2434 patients treated in our center, 1797 had acute Q fever and 48 had acute Q fever endocarditis. In 35 cases (72%), transthoracic echocardiography (TTE) identified a valvular lesion of acute Q fever endocarditis without underlying valvulopathy. Positive anticardiolipin antibodies (>22 immunoglobulin G-type phospholipid units [GPLU]) were independently associated with acute Q fever endocarditis (odds ratio [OR], 2.7 [95% confidence interval {CI}, 1.3-5.5]; P = .004). Acute Q fever endocarditis (OR, 5.2 [95% CI, 2.6-10.5]; P < .001) and age (OR, 1.7 [95% CI, 1.1-1.9]; P = .02) were independent predictors of progression toward persistent C. burnetii endocarditis. Systematic TTE in acute Q fever patients offers a unique opportunity for early diagnosis of acute Q fever endocarditis and for the prevention of persistent endocarditis. Transesophageal echocardiography should be proposed in men, aged >40 years, with anticardiolipin antibodies >60 GPLU when TTE is inconclusive or negative.

Successful transcatheter aortic valve replacement in a kidney allograft patient on rapamycin

Aortic valvular stenosis producing hemodynamic compromise is a major determinant of allograft function in kidney transplant recipients. Here, we describe successful transcatheter aortic valve replacement in a 59-year-old patient who had a kidney transplantation 14 years ago on 3 drug maintenance immunosuppression, including rapamycin.

Intramyocardial Calcification As A Rare But Significant Indication For Transfemoral TAVI?

We report on a 69-year-old female patient with severe valvular aortic stenosis who was hospitalized for cardiac decompensation for aortic valve replacement. Preoperative imaging (X-Ray, cat-scan and CMR) revealed significant and extraordinary intramyocardial calcification pronounced globally in the left ventricle and around the mitral valve. Due to high operative/surgical risk we preferred to approach an aortic valve replacement by transfemoral transcatheter procedure (TAVI-TF). Within the context of an undeniably elevated risk for ventricular injuries and dissections in conventional operations, highly progressed myocardial calcifications should lead to consider and prefer the transfemoral transcatheter aortic valve replacement procedure. &#x0D; Keywords: Aortic stenosis, intramyocardial calcification, transcatheter aortic valve replacement.

Role of lipoprotein (a) and LPA KIV2 repeat polymorphism in bicuspid aortic valve stenosis and calcification: a proof of concept study.

Hemodynamic valvular impairment is a frequent determinant of the natural history of bicuspid aortic valve (BAV). The role of elevated Lp(a) levels and LPA Kringle IV type 2 (KIV-2) size polymorphism in influencing aortic valve calcification and stenosis development in patients with tricuspid aortic valve was recognized. In this study, we investigate the association between Lp(a) and LPA KIV-2 repeat number, and the presence of calcification and stenosis in BAV patients. Sixty-nine patients [79.7% males; median age 45(30-53) yrs], consecutively referred to Center for Cardiovascular Diagnosis or Referral Center for Marfan syndrome or related disorders, AOU Careggi, from June to November 2014, were investigated. For each patient, clinical (ECG and echocardiography) and laboratory [Lp(a) (Immunoturbidimetric assay) and LPA KIV-2 repeat number (real-time PCR)] evaluation were performed. Patients were compared with 69 control subjects. No significant association between Lp(a) circulating levels and LPA KIV-2 repeat number and BAV was evidenced. Among BAV patients, significantly higher Lp(a) levels according to calcification degree were found [no calcifications:78(42-159)mg/L, mild/moderate: 134(69-189)mg/L; severe: 560(286-1511)mg/L, p = 0.008]. Conversely, lower LPA KIV-2 repeat numbers in subjects with more severe calcification degree were observed. Furthermore, higher Lp(a) levels in patients with aortic stenosis [214(67-501)mg/L vs 104(56-169)mg/L, p = 0.043] were also found. In conclusion, present data suggest the potential role for Lp(a) as a possible risk marker useful to stratify, among BAV patients, those with a higher chance to develop valvular calcifications and aortic stenosis.

Echocardiographic Follow-Up of Congenital Aortic Valvular Stenosis II.

We evaluated the natural course of congenital aortic valvular stenosis (AVS) and factors affecting AVS progression during long-term follow-up with echocardiography. Medical records of 388 patients with AVS were reviewed; patients with concomitant lesions other than aortic regurgitation (AR) were excluded. Trivial AVS was defined as a transvalvular Doppler peak systolic instantaneous gradient of < 25mmHg; mild stenosis, 25-49mmHg; moderate stenosis, 50-75mmHg; and severe stenosis, > 75mmHg. Median age of the patients was 3years (range 0day to 21years), and 287 (74%) were male. A total of 355 patients were followed with medical treatment alone for a median of 4.6years (range 1month to 20.6years), and the degree of AVS increased in 75 (21%) patients. The risk of AVS progression was higher when AVS was diagnosed in neonates (OR 4.29, CI 1.81-10.18, p = 0.001) and infants (OR 3.79, CI 2.21-6.49, p = 0.001). After the infancy period, bicuspid valve morphology increased AVS progression risk (OR 2.4, CI 1.2-4.6, p = 0.034). Patients with moderate AVS were more likely to have AVS progression (OR 2.59, CI 1.3-5.1, p = 0.006). Bicuspid valve morphology increased risk of AR development/progression (OR 1.77, CI 1.1-2.7, p = 0.017). The patients with mild and moderate AVS were more likely to have AR development/progression (p = 0.001). The risk of AR development/progression was higher in patients with AVS progression (OR 2.25, CI 1.33-3.81, p = 0.002). Newborn babies and infants should be followed more frequently than older patients according to disease severity. Bicuspid aortic valve morphology and moderate stenosis are risk factors for the progression of AVS and AR.

Nt-ProBNP Discriminatory Role Between Symptomatic and Asymptomatic Patients with Severe Valvular Aortic Stenosis.

Abstract Background: The aim was to evaluate the Nt-proBNP discriminatory role between symptomatic and asymptomatic patients with severe aortic stenosis. Methods: 187 patients with severe valvular aortic stenosis, with normal EF &gt; 50%, were included, 61 asymptomatic and 126 symptomatic. We used clinical, laboratory (Nt-proBNP) and echocardiographic parameters. Endpoints of monitoring (occurrence of event) were: the onset of symptoms in asymptomatic patients and death in both groups. Results: The symptomatic group with severe AS had a significantly higher means of Nt-proBNP, in comparison with the asymptomatic group. Nt-proBNP was a significant predictor for the risk of event occurrence (HR 1.4). In the group of severe AS without CAD (n = 101), the subgroup with Nt-proBNP above the cut-off value, took significantly higher percentage of patients with chest pain, fatigue and syncope. In the group with Nt-proBNP above the cut-off value, we had a significantly higher percentage of patients with severe AS without CAD, compared to those with CAD (n = 142). Nt-proBNP was negatively correlated with AVA and LVEF, whether the positive correlation was expressed for: LVEDd, LVEDs, IVSd, AV_Vmax, AV_MaxGrad, LVM and LA. Patients with Nt-proBNP above the cut-off, had a significantly lower event free survival, compared to patients with Nt-proBNP below the cut-off (n = 187; n = 101). Conclusion: The Nt-proBNP cut-off&gt; 460 pg/ml was confirmed as a useful tool in the determination of event free survival in patients with severe AS. Nt-proBNP not only had relevance in the assessment of the severity of the disease, but also was a significant predictor for the risk of event occurrence.

Comparison of Balloon Dilatation and Surgical Valvuloplasty in Non-critical Congenital Aortic Valvular Stenosis at Long-Term Follow-Up

The two main modalities used for congenital aortic valvular stenosis (AVS) treatment are balloon aortic valve dilatation (BAD) and surgical aortic valvuloplasty (SAV). This study evaluates residual and recurrent stenosis, aortic regurgitation (AR) development/progression, reintervention rates, and the risk factors associated with this end point in patients with non-critical congenital AVS who underwent BAD or SAV after up to 18years of follow-up. From 1990 to 2017, 70 consecutive interventions were performed in patients with AVS, and 61 were included in this study (33 BADs and 28 SAVs). There were no significant differences in age, sex distribution, PSIG, and AR frequency between the BAD and SAV groups. Bicuspid valve morphology was more common in the BAD group than the SAV group. There was no statistically significant difference between PSIGs and AR development or progression after intervention at the immediate postoperative echocardiography of patients who underwent BAD or SAV (p = 0.82 vs. p = 0.29). Patients were followed 6.9 ± 5.1years after intervention. The follow-up period in the SAV group was longer than that of the BAD group (9.5 ± 5.4 vs. 5.5 ± 4.4 years, p = 0.003). There was no statistically significant difference in the last echocardiographic PSIG between patients who underwent SAV or BAD (51.1 ± 33.5 vs. 57.3 ± 35.1, p = 0.659). Freedom from reintervention was 81.3% at 5years and 57.5% at 10years in the BAD group and 95.5% at 5years and 81.8% at 10years in the SAV group, respectively (p = 0.044). There was no difference in postprocedural immediate PSIG and last PSIG at follow-up and the development/progression of AR between patients who were treated with BAD versus SAV. However, long-term results of SAV were superior to those of BAD, with a somewhat prolonged reintervention interval.

Aortic valve bypass surgery in severe aortic valve stenosis: Insights from cardiac and brain magnetic resonance imaging

ObjectiveTo investigate and describe the distribution of aortic and cerebral blood flow (CBF) in patients with severe valvular aortic stenosis (AS) before and after aortic valve bypass (AVB) surgery. MethodsWe enrolled 10 consecutive patients who underwent AVB surgery for severe AS. Cardiovascular magnetic resonance imaging (CMR) and brain magnetic resonance imaging were performed as baseline before surgery and twice after surgery. Quantitative flow measurements were obtained using 1.5-T magnetic resonance imaging (MRI) scanner phase-contrast images of the ascending aorta, descending thoracic aorta (3 cm proximally and distally from the conduit-to-aorta anastomosis), and ventricular outflow portion of the conduit. The evaluation of CBF was performed using 3.0-T MRI scanner arterial spin labeling (ASL) through sequences acquired at the gray matter, dorsal default-mode network, and sensorimotor levels. ResultsConduit flow, expressed as the percentage of total antegrade flow through the conduit, was 63.5 ± 8% and 67.8 ± 7% on early and mid-term postoperative CMR, respectively (P < .05). Retrograde perfusion from the level of the conduit insertion in the descending thoracic aorta toward the aortic arch accounted for 6.9% of total cardiac output and 11% of total conduit flow. We did not observe any significant reduction in left ventricular stroke volume at postoperative evaluation compared with preoperative evaluation (P = .435). No differences were observed between preoperative and postoperative CBF at the gray matter, dorsal default-mode network, and sensorimotor levels (P = .394). ConclusionsAfter AVB surgery in patients with severe AS, cardiac output is split between the native left ventricular outflow tract and the apico-aortic bypass, with two-thirds of the total antegrade flow passing through the latter and one-third passing through the former. In our experience, CBF assessment confirms that the flow redistribution does not jeopardize cerebral blood supply.

Treatment of valvular aortic stenosis in children: a 20-year experience in a single institution.

This study presents short- and long-term follow-up after treatment for isolated valvular aortic stenosis in children with surgical valvotomy as the preferred 1st intervention. All patients aged 0-18 years treated between 1994 and 2013 at our centre were reviewed regarding the mode of first treatment, mortality, reinterventions and the need for aortic valve replacement. A total of 113 patients were identified in local registries. There were 44 neonates, 31 infants and 38 children. The mean follow-up period was 11 years (range 2-22 years). No early deaths and only 2 late deaths were reported. Of the 113 patients, 92 patients had open surgical valvotomy as the 1st intervention. Freedom from reintervention was 80%, 69%, 61%, 57% and 56% at 1, 5, 10, 15 and 20 years, respectively. The main indication for reintervention was valvular stenosis. Freedom from aortic valve replacement was 67%. Surgical valvotomy of aortic stenosis in this long-term follow-up study resulted in no 30-day mortality and <1% late mortality. Reinterventions were common, with 38% of the patients having further surgery or catheter treatment of the aortic valve before the age of 18 years. Among the 40 patients aged 18 years or older at follow-up, 45% had had the aortic valve replaced. Our data do not allow comparison of catheter and surgical treatment, but, based on these results, we find no reason to change our current policy of surgical treatment as 1st intervention in patients with isolated valvular aortic stenosis.

Aortic pseudocoarctation: a very rare finding

A 52-year-old Caucasian woman with a history of hypertension since age 30 was referred to cardiology department due to aortic stenosis. She had exertional dyspnoea, without thoracic pain or syncope....

The mystery of defining aortic valve area: what have we learnt from three-dimensional imaging modalities?

Aortic valve area is one of the main criteria used by echocardiography to determine the degree of valvular aortic stenosis, and it is calculated using the continuity equation which assumes that the flow volume of blood is equal at two points, the aortic valve area and the left ventricular outflow tract (LVOT). The main fallacy of this equation is the assumption that the LVOT area which is used to calculate the flow volume at the LVOT level is circular, where it is often an ellipse and sometimes irregular. The aim of this review is to explain the physiology of the continuity equation, the different sources of errors, the added benefits of using three-dimensional imaging modalities to measure LVOT area, the latest recommendations related to valvular aortic stenosis, and to introduce future perspectives. A literature review of studies comparing aortic valve area and LVOT area, after using three-dimensional data, has shown underestimation of both measurements when using the continuity equation. This has more impact on patients with discordant echocardiographic measurements when aortic valve area is disproportionate to haemodynamic measurements in assessing the degree of aortic stenosis. Although fusion imaging modalities of LVOT area can help in certain group of patients to address the issue of aortic valve area underestimation, further research on introducing a correction factor to the conventional continuity equation might be more rewarding, saving patients additional tests and potential radiation, with no clear evidence of cost-effectiveness.

The result of emergency cardiac intervention in resuscitated out-of-hospital cardiac arrest patients

Background: Arrhythmia and sudden cardiac decompensation (acute myocardial infarct or acute heart failure) are the most often causes of out-of-hospital cardiac arrest (OHCA). Emergency cardiac catheterization followed by coronary revascularization (percutaneous coronary intervention [PCI] or coronary artery bypass grafting surgery [CABG]) or valvular surgery is a lifesaving procedure. However, the result of this emergency room resuscitated OHCA patients underwent cardiac invasive procedure was not well defined before. Materials and Methods: One hundred and seventy (including 23 traumatic and stroke, etc.,) out of 705 OHCA patients were resuscitated and achieved a return of spontaneous circulation (ROSC) at Emergency Room of Chung Shan Medical University Hospital from January 1, 2011, to March 31, 2015. Only 23 (M/F = 25/8) out of 147 medically resuscitated OHCA patient with one or more cardiac risk factors were transferred for emergency cardiac catheterization (33/147). Thirty-one of them (31/33) underwent PCI (either balloon angioplasty or stent deployment) with coronary culprit stenotic lesions (>70%) of right coronary artery (15), left anterior descending artery (12), circumflex branch of left coronary artery (5), and left main coronary artery (1). One of the rest two patients with aortic valvular stenosis who underwent aortic valve replacement; and another with triple vessel disease of coronary artery received CABG. Results: All 33 patients (22.4%) survived the catheterization procedures and were sent to intensive care units. 31 patients were in comatose state and 24 eventually deceased due to cardiogenic shock (16), septic shock (4), ventricular tachycardia and ventricular fibrillation (2), hyperkalemia (1) and multiple organ failure (1). Nine patients (27.3%) survived to hospital discharge and were followed up at OPD periodically (1.3–43 months, mean 30.4 months). Four OHCA patients required extra-corporeal membrane oxygenation support, but only one out of four underwent PCI and survived. Conclusions: The resuscitated OHCA (ROSC) patients with any cardiac disease in the past should undergo emergency cardiac catheterization and possible intervention procedure with an acceptable result (survival to hospital discharge rate of 27.3%).

Non-Vitamin K Antagonist Oral Anticoagulants (NOAC) for Stroke Prevention in Atrial Fibrillation and Valvular Heart Disease – Systematic Review

BACKGROUND: Non-vitamin K antagonist oral anticoagulants (NOACs) are commonly used for stroke prophylaxis in patients with atrial fibrillation (AF), but their efficacy and safety in patients with underlying valvular heart disease (VHD) is unknown. METHODS: A search of MEDLINE, CENTRAL, Embase, clinicaltrials.gov was performed with the terms direct oral antiocoagulants, new oral anticoagulants, DOAC, NOAC, rivaroxaban, apixaban, dabigatran, valvular heart disease, aortic stenosis, aortic regurgitation, mitral regurgitation, tricuspid stenosis, tricuspid regurgitation, pulmonary stenosis and pulmonary regurgitation. Only clinical studies with clinical endpoints that compared NOACs with warfarin in patients with AF and identified VHD were included. RESULTS: Four clinical studies were retrieved based on our search criteria. Subgroup analysis of the landmark trials comparing a NOAC to warfarin in AF patients with underlying VHD demonstrated that NOACs had similar or superior efficacy in stroke prevention compared to warfarin. The risk of bleeding with NOACs compared to warfarin in these patients yielded inconsistent results. CONCLUSION: Based on the available evidence, NOACs provide similar or superior stroke reduction compared to warfarin in patients with AF and VHD, especially in aortic valve disease and mitral regurgitation. The rate of major bleeding between NOACs and warfarin in this patient population is unclear.

Antihypertensive Treatment in Severe Aortic Stenosis.

Previously, antihypertensive treatment in severe aortic stenosis was considered a relative contraindication. However, recent studies have shown that antihypertensive treatment may be safe and even beneficial in terms of reducing the progression of left ventricular pressure overload and even retarding the progression of valvular aortic stenosis. To date, no randomized clinical trials have been performed and no definite treatment guideline exist for the proper antihypertensive regimens. Antihypertensive treatment with β-blockers has generally been avoided in patients with severe aortic stenosis (AS) due to the concerns for inducing left ventricular dysfunction and hemodynamic compromise in the presence of severe outflow tract obstruction. Although it remains unclear whether antihypertensive treatment with a β-blocker is associated with increased risk of cardiovascular events in patients with AS, recent studies have shown that the use of β-blockers may be safe and may even be beneficial. Renin-angiotensin system (RAS) are upregulated in AS and have been shown to be involved in valve calcification and progression in both experimental models and in human trials. As such, theoretically, RAS inhibition would have benefit in retarding the progression of valvular stenosis as well as have benefit in left ventricle remodeling. Recent clinical studies are indeed showing that use of RAS inhibition may be beneficial in patients with AS. Future clinical trials to establish the ideal target blood pressure and antihypertensive regimens in severe AS is essential.