Indications for aortic valve replacement in aortic stenosis

Aortic stenosis is a common condition, particularly in the elderly. The treatment is surgical, and any patient with symptomatic severe aortic stenosis should be considered for aortic valve replacement. Aortic stenosis causes an increase in afterload to the left ventricle, which when severe can lead to hemodynamic instability. Although the therapy of aortic stenosis is valve replacement, determining whether a patient has symptoms and accurately assessing the severity of stenosis can be difficult. The management of patients with severe aortic stenosis in the intensive care unit setting can be very challenging, particularly when comorbid medical conditions make aortic valve replacement difficult. This article reviews the diagnosis of aortic stenosis, methods of assessing symptoms and severity, and management of severe symptomatic stenosis, particularly in the intensive care unit setting. Components of the history that suggest symptomatic aortic stenosis are presented. The role of physical examination is discussed, as are the echocardiographic means of determining stenosis severity. Other means of assessing severity are addressed, as are circumstances in which there can be difficulty in interpretation, such as severe aortic stenosis and left ventricular dysfunction. Management of patients, focusing on the intensive care unit setting, is reviewed, with a focus on the timing of aortic valve replacement.     

The spectrum of left ventricular filling in severe aortic stenosis

To assess left ventricular diastolic filling in valvular aortic stenosis, pulsed Doppler echocardiography was used prospectively in 35 patients with severe aortic stenosis (valve area < 1 cm²) and in 38 age-matched normal subjects. Twenty-seven patients had a normal left ventricular systolic function at rest (ejection fraction > 0.50) and a normal or only slightly increased mean pulmonary capillary wedge pressure (mean 11±4 mm Hg). Eight patients had a poor left ventricular systolic function (ejection fraction: 0.28±0.10) and an elevated mean pulmonary capillary wedge pressure (mean: 36±9 mm Hg). The Doppler derived filling parameters were correlated with hemodynamic data, left ventricular wall thickness derived from M-mode echocardiograms, heart rate and atrio-ventricular (A-V) conduction delay using stepwise multiple correlation. The data of this study suggest that left ventricular filling is significantly impaired in patients with severe aortic stenosis and left ventricular hypertrophy with an increase in late diastolic (A-wave) velocity, an increase in the A/E ratio, a decrease in the first one-half filling fraction and a prolongation of early diastolic deceleration time. These changes in filling hemodynamics are associated with alterations in mean pulmonary capillary wedge pressure, left ventricular wall thickness, heart rate and A-V conduction delay. When heart failure develops as a result of impaired left ventricular systolic function, an increase in left atrial filling pressure is associated with a shift of left ventricular filling towards early diastole with a ‘normalisation’ of the transmitral flow velocity curve. In extreme cases, a progression towards a ‘restrictive’ filling pattern is found with a marked shortening of the left ventricular early diastolic deceleration time. In the presence of high filling pressures, increased left atrial driving pressure (derived from the mean pulmonary capillary wedge pressure) is associated with changes in the left ventricular filling pattern irrespective of the presence and the degree of myocardial hypertrophy.     

Markers of left ventricular decompensation in aortic stenosis

Calcified aortic stenosis is a condition that affects the valve and the myocardium. As the valve narrows, left ventricular hypertrophy occurs initially as an adaptive mechanism to maintain cardiac output. Ultimately, the ventricle decompensates and patients transition towards heart failure and adverse events. Current guidelines recommend aortic valve replacement in patients with severe aortic stenosis and evidence of decompensation based on either symptoms or an impaired ejection fraction <50%. However, symptoms can be subjective and correlate only modestly with the severity of aortic stenosis whilst impaired ejection fraction is an advanced manifestation and often irreversible. In this review, the authors will discuss the pathophysiology of left ventricular hypertrophy and the transition to heart failure. Subsequently, the authors will examine novel biomarkers that may better identify the transition from hypertrophy to heart failure and therefore guide the optimal timing for aortic valve replacement.     

伴左室扩大和左室收缩功能降低的重度主动脉瓣狭窄患者行瓣膜置换术的疗效评价

目的评价单纯重度主动脉瓣狭窄合并左室扩大和左室射血分数减低及左心衰的患者行主动脉瓣置换术后的临床疗效和心功能改变。方法采集因单纯重度主动脉瓣狭窄（AS）（瓣口面积〈1．0cm^2）伴左室扩大、左室射血分数减低和左心衰而行主动脉瓣置换术的患者15例。术前二维超声心动图测量左室舒张末期内径（LVDd）、左室后壁厚度（PWTd）和室间隔厚度（IVSTd）,计算左室重量指数（LVMI）,Simpson法测量LVEF以及连续多普勒测量主动脉瓣跨瓣血流速度和最大压力阶差（AVP）。术后1周复查超声心动图,并于术后3个月至3年随访观察。结果15例患者术后一周症状改善,AVP由平均（112±66）mmHg显著降至（28±17）mmHg（P〈0．05）。平均随访1．6±1．3年期间,心衰症状改善明显,纽约心脏病学会（NYHA）心功能分级由3．3±0．5级降至1．7±0．9（P〈0．05）,与术前相比,LVDd有显著的降低、LVEF显著性增加（P〈0．05）,与术后1周比较也有改善;LVMI与术前和术后1周比较均有一定程度的降低,尽管尚无显著性差异（P〉0．05）;AVP在术后1周已有显著降低的基础上,在随访期间无明显变化（P〉0．05）。4例患者在随访期间死亡,其中因心源性死亡的3例患者均是合并严重冠脉三支病变曾同时行冠脉搭桥术。结论单纯重度主动脉瓣狭窄合并左室扩大、左室射血分数降低和左心衰的患者,外科主动脉瓣置换术是有效的治疗方法,术后跨主动瓣压差、左室内径及左室射血分数均有明显改善。合并严重冠状动脉狭窄或术前跨主动脉瓣压差较低的患者应进一步评价其手术风险及获益。     

主动脉瓣人工瓣膜置换术后室间隔运动异常的超声研究

【】目的：二维超声心动图对主动脉瓣人工瓣膜置换术后室间隔运动异常的超声研究。方法：利用二维超声心动图对58例主动脉瓣重度狭窄患者及16例主动脉瓣重度关闭不全患者行超声心动图检查,测量术前及术后7天左室射血分数、左室心搏量、每分输出量、室间隔运动幅度、室间隔增厚率。结果：主动脉瓣狭窄和主动脉瓣关闭不全患者术后左室EF值降低,差异无统计学意义；左室心搏量(SV)及每分输出量(CO)升高,差异有统计学意义；室间隔运动幅度减低,差异有统计学意义；室间隔增厚率未见明显差异。结论：二维超声心动图能很好的评价主动脉瓣人工瓣膜置换术后室间隔运动异常及其对左室整体收缩功能的影响。     

Transcatheter treatment of complex pulmonic and aortic valvular disease following failed Ross procedure

A 63‐year‐old man with congenital bicuspid aortic valve disease and complex surgical history (that includes a Ross procedure complicated by cardiac arrest requiring emergency coronary artery bypass graft surgery, multiple subsequent sternotomies to treat a failed pulmonic homograft and pseudoaneurysm repair of the left and right ventricular outflow tracts (LVOT/RVOT), bioprosthetic aortic valve replacement, and aortic valve endocarditis) presented with worsening heart failure symptoms secondary to bioprosthetic aortic valve failure and recurrent pulmonic valve stenosis successfully treated with transcatheter intervention.     

Acute improvement in arterial-ventricular coupling after transcatheter aortic valve implantation (CoreValve) in patients with symptomatic aortic stenosis

The recent development of transcatheter aortic valve implantation (TAVI) to treat severe aortic stenosis (AS) offers a viable option for high-risk patients categories. Our aim is to evaluate the early effects of implantation of CoreValve aortic valve prosthesis on arterial-ventricular coupling by two dimensional echocardiography. Sixty five patients with severe AS performed 2D conventional echocardiography before, immediately after TAVI, at discharge (mean age: 82.6?±?5.9?years; female: 60%). The current third generation (18-F) CoreValve Revalving system (Medtronic, Minneapolis, MN) was used in all cases. Vascular access was obtained by percutaneous approach through the common femoral artery; the procedure was performed with the patient under local anesthesia. We calculated, apart the conventional parameters regarding left ventricular geometry and the Doppler parameters of aortic flow (valvular load), the vascular load and the global left ventricular hemodynamic load. After TAVI we showed, by echocardiography, an improvement of valvular load. In particular we observed an immediate reduction of transaortic peak pressure gradient (P?<?0.0001), of mean pressure gradient (P?<?0.0001) and a concomitant increase in aortic valve area (AVA) (0.97?±?0.3?cm²). Left ventricular ejection fraction improved early after TAVI (before: 47?±?11, after: 54?±?11; P?<?.0001). Vascular load, expressed by systemic arterial compliance, showed a low but significant improvement after procedure (P?<?0.01), while systemic vascular resistances showed a significant reduction after procedure (P?<?0.001). As a global effect of the integrated changes of these hemodynamic parameters, we observed a significant improvement of global left ventricular hemodynamic load, in particular through a significant reduction of end-systolic meridional stress (before: 80?±?34 and after: 55?±?29, P?<?0.0001). The arterial-valvular impedance showed a significant reduction (before: 7.6?±?2 vs after: 5.8?±?2; P?<?0.0001. Furthermore we observed a significant reduction with a normalization of arterial-ventricular coupling (P?<?0.005). With regard to left ventricular (LV) efficiency, we observed, after the procedure, a significant reduction of stroke work (P?<?0.001) and potential energy (P?<?0.001), with a significant increase of work efficiency early after the procedure (P?<?0.001). Our results showed that the TAVI procedure was able to determine an early improvement of the global left ventricular hemodynamic load, allowing a better global LV performance. Further follow-up investigations are needed to evaluate these results in a more prolonged time observation.     

自体心包补片修补主动脉瓣环辅助主动脉瓣置换

背景：在主动脉置换过程中常遇到瓣环钙化、瓣周囊肿等特殊情况,这时一般应用特殊技术辅助主动脉瓣置换。目的：观察自体心包补片修补主动脉瓣环辅助主动脉瓣置换治疗钙化性主动脉瓣狭窄并瓣环钙化的临床可行性。方法：回顾性分析2009年1月至2012年1月郑州大学第一附属医院42例钙化性主动脉瓣狭窄并瓣环钙化患者的临床资料,并通过统计学软件处理自体心包补片修补主动脉瓣环技术辅助主动脉瓣置换前后的主动脉瓣有效瓣口面积指数、最大跨瓣压差、血流峰值速度、左室射血分数等数据,分析自体心包补片修补主动脉瓣环技术辅助主动脉瓣置换的应用效果。结果与结论：无置换中死亡病例,置换中主动脉阻断时间为52-88（63.0±18.1）min,体外循环时间为78-122（102.6±25.1）min,置换后1例患者出现急性肾功能衰竭,经床旁血透治疗后治愈。余患者无严重置换并发症。置换后住院天数为7-20（13.6±5.5）d。置换后多普勒超声心动图示：瓣膜功能良好,均未发现主动脉瓣周漏。置换后6个月的主动脉瓣有效瓣口面积指数、最大跨瓣压差、血流峰值速度、左室射血分数均有显著改善,与置换前比较差异均有显著性意义（P〈0.05）。证实对置换适应证合适的特殊换瓣患者,自体心包补片修补主动脉瓣环辅助主动脉瓣置换可取得满意的外科治疗效果,且操作安全简单,是一项可行的技术。     

Global strain in severe aortic valve stenosis: relation to clinical outcome after aortic valve replacement

Background- Global longitudinal systolic strain (GLS) is often reduced in aortic stenosis despite normal ejection fraction. The importance of reduced preoperative GLS on long-term outcome after aortic valve replacement is unknown. Methods and Results- A total of 125 patients with severe aortic stenosis and ejection fraction >40% scheduled for aortic valve replacement were evaluated preoperatively and divided into 4 groups according to GLS quartiles. Patients were followed up for 4 years. The primary end points were major adverse cardiac events (MACEs) defined as cardiovascular mortality and cardiac hospitalization because of worsening of heart failure; the secondary end point was cardiovascular mortality. MACE and cardiac mortality were significantly increased in patients with lower GLS. Estimated 5-year MACE was increased: first quartile 19% (n=6) / second quartile 20% (n=6) / third quartile 35% (n=11) / fourth quartile 49% (n=15); P=0.04. Patients with increased age, left ventricular hypertrophy, and left atrial dilatation were at increased risk. In Cox regression analysis, after correcting for standard risk factors and ejection fraction, GLS was found to be significantly associated with cardiac morbidity and mortality. In a stepwise Cox model with forward selection, GLS was the sole independent predictor: hazard ratio=1.13 (95% confidence interval, 1.02-1.25), P=0.04. Comparing the overall log likelihood χ(2) of the predictive power of the multivariable model containing GLS was statistically superior to models based on EuroScore, history with ischemic heart disease, and ejection fraction. Conclusions- In patients with symptomatic severe aortic stenosis undergoing aortic valve replacement, reduced GLS provides important prognostic information beyond standard risk factors. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00294775.     

Mechanical deformation in adult patients with unrepaired aortic coarctation

Aortic coarctation is a congenital heart disease that causes an increased left ventricular afterload, resulting in increased systolic parietal tension, compensatory hypertrophy, and left ventricular systolic and diastolic dysfunction. The speckle tracking is a new echocardiographic technique that allows the detection of subclinic left ventricular systolic dysfunction. The aim of this study was to detect early left ventricular dysfunction using mechanical deformation by echocardiography in adults with un-repaired aortic coarctation. A total of 41 subjects were studied, 20 patients with aortic coarctation and 21 control subjects, 21 women (51.2%), with an average age of 30?±?10 years. All patients with aortic coarctation had systemic arterial hypertension (p?<?0.001). Seventy percent (14/20) of the patients had bicuspid aortic valve. Statistically significance (p?<?0.005) were found in left ventricular mass index, E/e ratio, pulmonary artery systolic pressure and peak velocity and maximum gradient of the aortic valve. The global longitudinal deformation of the left ventricle in patients with aortic coarctation was significative decreased, p?<?0.001. The ejection fraction and the global longitudinal deformation of the left ventricle were significantly lower in patients with aortic coarctation compared to the control group, p?<?0.003, p?<?0.001, respectively. The subgroup of patients with coarctation and left ventricular ejection fraction?<?55% had a marked decrease in global longitudinal strain (??15.9?±?4%). The radial deformation was increased in patients with aortic coarctation and showed a trend to be significant (r?=?0.421; p?<?0.06). A significant negative correlation was observed between the global longitudinal deformation and left ventricular mass index (r?=?0.54; p?=?0.01) in the aortic coarctation group. The patients with aortic coarctation and left ventricular hypertrophy had marked reduction of left ventricular global longitudinal deformation (??16%, p?<?0.05). In our study patients with normal left ventricular ejection fraction had abnormal global longitudinal deformation and also the increased left ventricular mass was related with a decreased left ventricular global longitudinal deformation as a sign of subclinical systolic dysfunction.     

双源CT血管造影综合评估StanfordA型主动脉夹层

目的 评价双源CT血管造影(DSCTA)综合评价Stanford A型主动脉夹层(AD)主动脉根部结构﹑冠状动脉和左心室功能的可行性。方法 对36例Stanford A型AD患者行术前心电门控DSCTA扫描,评价冠状动脉、主动脉及主动脉瓣膜图像质量及受累情况,测量主动脉根部管径和左心室功能,计算辐射剂量。将DSCTA结果与手术所见进行比较。结果 35例患者成功完成DSCTA检查。97.14%(34/35)的胸主动脉和主动脉瓣膜图像、93.10%(445/478)的冠状动脉节段图像可用于诊断。右窦受累17例,无窦受累15例,左窦受累5例;右-无窦交界受累13例,左-右窦交界受累3例,左-无窦交界受累1例。主动脉窦部直径(41.6±9.4)mm;瓣环直径(28.2±4.1)mm;窦管交界直径(73.6±10.2)mm。左心室射血分数与主动脉根部受累程度呈负相关(r=-0.97,P=0.02)。平均有效辐射剂量为(21.96±4.36)mSv。DSCTA结果与手术病理诊断一致率(30/34,88.24%)和一致性(Kappa=0.82,P<0.01)均较高。结论 DSCTA"一站式"检查综合评价Stanford A型AD主动脉根部结构﹑冠状动脉和左心功能安全可靠。     

Noninvasive assessment of myocardial dysfunction in patients with chronic aortic regurgitation

Chronic aortic regurgitation may have minimal symptoms until severe myocardial dysfunction is apparent. Multiple preoperative indicators of postoperative prognosis have been sought. It appears that an elevated left ventricular end systolic dimension on echocardiography or elevated end systolic volume on radionuclide ventriculography in combination with depressed LV function and substantially increased calculated systolic wall stress may present an indicator for aortic valve replacement. Response of ejection fraction to stress may not be as reproducible, but when combined with a depressed resting ejection fraction may also be an indicator for aortic valve replacement. Even patients with severely depressed left ventricular ejection fraction may improve with surgery; however, the risks of a poor postoperative outcome is substantial increased. Appropriate management of a patient with chronic aortic regurgitation requires monitoring of multiple parameters during the patient's clinical course for optimal timing of valve replacement surgery.     

纵向应变评估主动脉瓣狭窄置换术后心肌功能

利用斑点追踪技术得出的纵向应变（LS）可发现射血分数下降前心肌收缩功能微小变化，在预测主动脉瓣狭窄（AS）患者主动脉瓣置换术（AVR）后死亡率及症状发展方面具有重要应用价值。本文针对应用LS评估AS患者AVR后心肌功能现状进行综述。     

Primary echocardiographic results of the Carpentier–Edwards Perimount Magna

Purpose

The aim of this study was to investigate the primary echocardiographic results of aortic valve replacement using 21- and 19-mm Carpentier–Edwards Perimount Magna bioprosthesis aortic xenografts in patients with small aortic annulus.

Methods

Twenty patients (mean body surface area 1.63?±?0.16?m²) underwent aortic valve replacement between June 2008 and December 2009. Eight and 12 patients received 21- and 19-mm Magna bioprostheses, respectively. After 12?months, hemodynamic data were obtained by echocardiography to estimate the prosthesis–patient mismatch.

Results

At follow-up, significant decreases in peak and mean left ventricular aortic pressure gradients were observed in the 12 patients with aortic stenosis (P?<?0.05). Regression of the left ventricular mass was observed in all the patients (P?<?0.05). The mean measured effective orifice area (EOA) and EOA index (EOAI) were 1.61?±?0.28?cm² and 0.99?±?0.16?cm²/m², respectively. Prosthesis–patient mismatch (EOAI ≤0.85) was documented in three patients.

Conclusion

The primary echocardiographic findings suggested that the hemodynamic performance of the 19- and 21-mm Carpentier–Edwards Perimount Magna bioprostheses was satisfactory in the patients with a small aortic annulus.     

多巴酚丁胺负荷超声心动图对低压力阶差低心排血量主动脉瓣狭窄的研究

目的 评价负荷超声心动图技术在诊断低跨瓣压力阶差-低心排量主动脉瓣狭窄中的作用。方法 对经临床拟诊和经胸超声心动图（TTE）确定为低跨瓣压力阶差-低心排量主动脉瓣狭窄的12例患者进行回顾性分析，并均行多巴酚丁胺超声心动图负荷试验予以确定病变性质。结果 8例患者呈重度主动脉瓣狭窄伴左心功能不全，左室有收缩储备，外科手术换瓣均成功（除1例死亡外）；其余4例予内科药物治疗。结论 多巴酚丁胺超声心动图负荷试验对鉴别低跨瓣压差低心排的主动脉瓣狭窄是有效、安全的方法。     

Alterations in aortic elasticity in noncompaction cardiomyopathy

Background Noncompaction cardiomyopathy (NCCM) is a recently recognized disorder frequently associated with systolic and diastolic heart failures. This study was designed to examine aortic stiffness in NCCM patients and to compare these results to age- and gender-matched controls. Methods A total of 20 patients with typical echocardiographic features of NCCM (age 38 ± 16 years, eight males) were investigated. Their results were compared to 20 age- and gender-matched controls. All subjects underwent a complete two-dimensional transthoracic echocardiographic examination. Systolic (SD) and diastolic (DD) ascending aortic diameters were recorded in M-mode at a level of 3 cm above the aortic valve from a parasternal long-axis view. Aortic stiffness index (β) was calculated as a characteristic of aortic elasticity, as ln(SBP/DBP)/[(SD - DD)/DD], where SBP and DBP are the systolic and diastolic blood pressures, respectively, and ln is the natural logarithm. Results The number of noncompacted segments in the NCCM patients was 4.6 ± 2.0. NCCM patients had significantly increased left ventricular dimensions and reduced left ventricular ejection fraction. Compared to controls, aortic stiffness index (β) was significantly increased in NCCM patients (8.3 ± 5.2 vs. 3.5 ± 1.1, p < 0.001). Conclusion Increased aortic stiffness can be observed in patients with NCCM with moderate to severe heart failure. These alterations may be due to neurohormonal changes in heart failure. Attila Nemes is a visiting fellow from the University of Szeged (Szeged, Hungary) and is supported by the Research Fellowship of the European Society of Cardiology. Osama I.I. Soliman and Ashraf M. Anwar are visiting fellows from the Al Azhar University (Cairo, Egypt) and are supported by the Egyptian Government.     

Quantitative assessment of systolic left ventricular function with speckle-tracking echocardiography in adult patients with repaired aortic coarctation

Despite successful aortic coarctation (CoA) repair, systemic hypertension often recurs which may influence left ventricular (LV) function. We aimed to detect early LV dysfunction using LV global longitudinal strain (GLS) in adults with repaired CoA, and to identify associations with patient and echocardiographic characteristics. In this cross-sectional study, patients with repaired CoA and healthy controls were recruited prospectively. All subjects underwent echocardiography, ECG and blood sampling within 1 day. With speckle-tracking echocardiography, we assessed LV GLS on the apical four-, three- and two-chamber views. We included 150 subjects: 75 patients (57 % male, age 33.4 ± 12.8 years, age at repair 2.5 [IQR: 0.1–11.1] years) and 75 healthy controls of similar sex and age. LV GLS was lower in patients than in controls (?17.1 ± 2.3 vs. ?20.2 ± 1.6 %, P < 0.001). Eighty percent of the patients had a normal LV ejection fraction, but GLS was still lower than in controls (P < 0.001). In patients, GLS correlated with systolic and diastolic blood pressure (r = 0.32, P = 0.009; r = 0.31, P = 0.009), QRS duration (r = 0.34, P = 0.005), left atrial dimension (r = 0.27, P = 0.029), LV mass (r = 0.30, P = 0.014) and LV ejection fraction (r = ?0.48, P < 0.001). Patients with either associated cardiac lesions, multiple cardiac interventions or aortic valve replacement had lower GLS than patients without. Although the majority of adults with repaired CoA seem to have a normal systolic LV function, LV GLS was decreased. Higher blood pressure, associated cardiac lesions, and larger left atrial dimension are related with lower GLS. Therefore, LV GLS may be used as objective criterion for early detection of ventricular dysfunction.     

Clinical outcome and functional characteristics of patients with asymptomatic low-flow low-gradient severe aortic stenosis with preserved ejection fraction are closer to high-gradient severe than to moderate aortic stenosis

Asymptomatic “paradoxic” severe low-flow low-gradient aortic stenosis with preserved ejection fraction (PAS) constitutes a challenging condition where the optimal management and follow-up remain elusive. We evaluated the clinical outcome in patients with PAS as compared to asymptomatic patients with moderate (MAS) or classical severe aortic stenosis (CAS). Consecutive asymptomatic moderate or severe aortic stenosis patients without concomitant other heart or lung disease (n?=?121) were invited. Participants (n?=?74) were assigned to three subgroups with regard to degree of aortic stenosis: MAS (n?=?25), CAS (n?=?22) and PAS (n?=?27). Echocardiographic parameters at baseline and clinical outcome data after >?3 years of follow-up time were obtained. Patients with PAS had the smallest stroke volumes and the highest relative wall thickness (p?<?0.05). Left ventricular mass index was highest in subjects with CAS, followed closely by PAS and eventually MAS subjects. Whereas ejection fraction was similar amongst the subgroups, a stepwise decrease in global longitudinal left ventricular strain with increasing degree of aortic stenosis was observed, with CAS patients displaying the lowest mean global longitudinal strain, followed by PAS and MAS. A trend towards increasing mortality rate by increasing degree of stenosis was observed. Patients with CAS underwent aortic valve replacement surgery more frequently than both PAS and MAS (p?<?0.001). These data suggest that echocardiographic parameters and clinical outcome in patients with PAS bear closer resemblance to CAS than to MAS, but management of PAS is more conservative than in CAS.     

Speckle tracking echocardiography derived 2-dimensional myocardial strain predicts left ventricular function and mass regression in aortic stenosis patients undergoing aortic valve replacement

Regression of left ventricular (LV) mass in severe aortic stenosis (AS) following aortic valve replacement (AVR) reduces the potential risk of sudden death and congestive heart failure associated with LV hypertrophy. We investigated whether abnormalities of resting LV deformation in severe AS can predict the lack of regression of LV mass following AVR. Two-dimensional speckle tracking echocardiography (STE) was performed in a total of 100 subjects including 60 consecutive patients with severe AS having normal LV ejection fraction (EF > 50 %) and 40 controls. STE was performed preoperatively and at 4 months following AVR, including longitudinal strain assessed from the apical 4-chamber and 2-chamber views and the circumferential and rotational mechanics measured from the apical short axis view. In comparison with controls, the patients with AS showed a significantly lower LV longitudinal (p < 0.001) and circumferential strain (p < 0.05) and higher apical rotation (p < 0.001). Following AVR, a significant improvement was seen in both strains (p < 0.001 for each respectively), however, apical rotation remained unchanged (p = 0.14). On multivariate analysis, baseline LV mass (odds ratio 1.02; p = 0.011), left atrial volume (odds ratio 0.81; p = 0.048) and circumferential strain (odds ratio 0.84; p = 0.02) independently predicted LV mass regression (>10 %) following AVR. In conclusion, STE can quantify the burden of myocardial dysfunction in patients with severe AS despite the presence of normal LV ejection fraction. Furthermore, resting abnormalities in circumferential strain at LV apex is related with a hemodynamic milieu associated with the lack of LV mass regression during short-term follow up after AVR.     

Transcatheter aortic valve implantation in patients with severely reduced left ventricular systolic function: a single-center experience

Aims

Current guidelines consider severe systolic left ventricular dysfunction [ejection fraction (EF) ≤20 %; left ventricular dysfunction (LVD)] a contraindication for transcatheter aortic valve implantation (TAVI). The purpose of this study was to evaluate the efficacy and safety of TAVI in this extreme risk subset of patients.

Methods and Results

The study population (253 patients) was divided into two groups; the LVD group [21 patients with left ventricular ejection fraction (LVEF) ≤20 %] and the control group (232 patients with LVEF >20 %). TAVI was generally performed transfemorally under analgosedation without mechanical circulatory support. Clinical and hemodynamic variables, as well as procedural and follow-up outcomes, were compared, and all events were defined according to the Valve Academic Research Consortium criteria for event definition. Mean EF in the LVD group was 18.3 ± 2.9 % compared to 50.9 ± 11.3 % in the control group. Patients in the LVD group were younger, more commonly males, had higher logistic EuroSCORE and lower mean aortic pressure gradients. Immediate procedural mortality was low and similar in both groups (0 vs. 2.2 % in the LVD and control group, respectively, p = 0.49). At 30 days, post-procedural vascular and bleeding complications as well as strokes were similar, but all-cause mortality was higher in the LVD group (14.3 vs. 3.4 %, p = 0.05). In the survivors of the LVD group, New York Heart Association functional class and LVEF significantly improved at 30 days and 6 months. Survival at 1 and 2 years was 70.2 vs. 86.0 % and 56.1 vs. 78.3 % in the LVD and control group, respectively (log-rank p = 0.03).

Conclusions

TAVI without mechanical circulatory support appears feasible, safe and effective in patients with severe aortic stenosis and severe LVD, but short- and long-term mortality remain high. TAVI should be considered a viable treatment option in this subset of extremely compromised patients.