Mitral Valve Dynamics in Severe Aortic Stenosis before and after Aortic Valve Replacement

Case presentation: A 66-year-old man is referred to a cardiologist for the evaluation of a heart murmur. The patient claims to be entirely asymptomatic, although his wife notes that he has decreased his physical activity over the past two years because he is “getting old.” At physical examination, his blood pressure was 120/70 mm Hg; pulse, 80 bpm; respiration, 13 breaths per minute; and temperature, 99.0°F. Cardiovascular examination revealed normal central venous pressure. His carotid upstrokes were reduced in volume and delayed in upstroke. Cardiac examination revealed a forceful sustained apical impulse in its normal position. There was a 3/6 late-peaking systolic ejection murmur heard at the right upper sternal border radiating to the neck. The rest of the physical examination was unremarkable. Echo-Doppler evaluation revealed an ejection fraction of 0.60, a left ventricular free wall thickness of 1.3 cm, and a peak transaortic flow velocity of 4.5 m/s. How should this patient be managed? Should he undergo aortic valve replacement now? Should he undergo longitudinal follow-up to monitor progression of his aortic stenosis? Over the past 40 years, diagnostic techniques, substitute cardiac valves, and valve implantation surgery have undergone continued improvement, reducing the risk of the valve replacement and enhancing its benefits. Thus, the risk-benefit analysis of valve surgery has tilted in favor of increasingly early intervention for valve disease. The following is a summary incorporating this concept into the current strategy for managing patients with aortic stenosis such as the one described above. The patient with severe aortic stenosis who presents with symptoms represents the most straightforward management strategy for the disease. Survival is nearly normal until the classic symptoms of angina, syncope, or dyspnea develop.1 However, only 50% of patients who present with angina survive 5 years, whereas 50% survival is 3 years for patients who …

Robotic aortic valve replacement

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Hypertrophy is considered one of the major mechanisms of the myocardium for adapting to hemodynamic overload. More muscle mass provides more contractile elements for generating the extra work required by the overload. In pressure overload of aortic valve stenosis, concentric left ventricular hypertrophy (LVH) normalizes wall stress, a key determinant of ejection performance.1 Afterload is often expressed as wall stress (pressure×radius/thickness). As the pressure term in the numerator increases, it is offset by an increase in the thickness term of the denominator. In this way, the high systolic pressure required to drive blood through even a very stenotic aortic valve can be consistent with normal afterload and normal ejection fraction. See p 3170 Unfortunately, hypertrophy not only provides benefits but also has many pathological consequences. One of these is myocardial ischemia and the attendant angina reported by patients with aortic stenosis despite normal epicardial coronary arteries. The onset of angina greatly increases the risk of sudden death compared with the risk in asymptomatic patients with aortic valve stenosis.2,3 Angina occurs when myocardial oxygen demand exceeds supply. Demand is proportional to heart rate and wall stress, and the latter can be elevated in cases of aortic stenosis when hypertrophy is inadequate to normalize stress.1 After aortic valve replacement, there is marked regression of hypertrophy that may occur over the next several months to years,4 but angina is relieved immediately. Relief of angina immediately after surgery is probably due to the combination of sudden decreased oxygen demand after removal of pressure overload and increased oxygen supply of improved perfusion. However, there are remaining questions about the physiological mechanisms for reduced myocardial oxygen supply (coronary blood flow) in aortic stenosis and its improvement after relief of pressure overload. Specifically, what is it about critical aortic stenosis that is “critical” …

Received October 26, 2004; revision received January 13, 2005; accepted February 4, 2005. Calcific aortic valve disease is a slowly progressive disorder with a disease continuum that ranges from mild valve thickening without obstruction of blood flow, termed aortic sclerosis, to severe calcification with impaired leaflet motion, or aortic stenosis (Figure 1). In the past, this process was thought to be “degenerative” because of time-dependent wear-and-tear of the leaflets with passive calcium deposition. Now, there is compelling histopathologic and clinical data suggesting that calcific valve disease is an active disease process akin to atherosclerosis with lipoprotein deposition, chronic inflammation, and active leaflet calcification. The overlap in the clinical factors associated with calcific valve disease and atherosclerosis and the correlation between the severity of coronary artery and aortic valve calcification provide further support for a shared disease process. Figure 1. Gross specimen of minimally diseased aortic valve (left) and severely stenotic aortic valve (right). In the severely stenotic valve, there are prominent lipocalcific changes on aortic side of valve cusps (arrow), with sparing of commissures. ### Anatomy of Normal Aortic Valve The normal aortic valve comprises 3 layers. The ventricularis, on the ventricular side of the leaflet, is composed of elastin-rich fibers that are aligned in a radial direction, perpendicular to the leaflet margin. The fibrosa, on the aortic side of the leaflet, comprises primarily fibroblasts and collagen fibers arranged circumferentially, parallel to the leaflet margin. The spongiosa is a layer of loose connective tissue at the base of the leaflet, between the fibrosa and ventricularis, composed of fibroblasts, mesenchymal cells, and a mucopolysaccharide-rich matrix. These layers work in concert to provide tensile strength and pliability for decades of repetitive motion. ### Early Lesion of Aortic Sclerosis Histopathologic studies of aortic sclerosis show focal subendothelial plaquelike lesions on the aortic side of the leaflet that extend to the adjacent fibrosa layer. Similarities to …

2019 AATS/ACC/ASE/SCAI/STS expert consensus systems of care document: A proposal to optimize care for patients with valvular heart disease: A joint report of the American Association for Thoracic Surgery, American College of Cardiology, American Society of Echocardiography, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons

Objective To evaluate left ventricular myocardial function alternation by three-dimensional speckle tracking imaging (3D-STI) after surgical aortic valve replacement (AVR) in severe aortic stenosis (AS) patients with preserved left ventricular ejection fraction (LVEF), and discuss its clinical value. Methods Forty patients with severe aortic stenosis who were hospitalized or outpatient in Nanjing First Hospital Affiliated to Nanjing Medical University during the period of October 2014 to October 2016 (AS group), and forty healthy volunteers (normal control group) were enrolled in this study. Normal control group underwent conventional echocardiography and 3D-STI measurement, while the AS group underwent conventional echocardiography and 3D-STI measurement at preoperative, 1 week postoperative and 3 months postoperative, then we obtained left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), interventricular septum thickness diameter (IVSd), left ventricular posterior wall thickness diameter (LVPWd), left ventricular ejection fraction (LVEF), global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS), global area strain (GAS) strain and 3D-strain. The independent sample t test was used to compare the difference of conventional ultrasound parameters and 3D-STI parameters between AS preoperative patients and healthy controls, AS patients at 3 months postoperative and healthy controls. The single factor analysis of variance was used to compare the difference of conventional ultrasound parameters and 3D-STI parameters in severe patients at preoperative, 1 week postoperative and 3 months postoperative. LSD-t test was used to compare in different AS groups. Results Compared with normal control group, IVSD, LVPWD and GCS of severe AS patients increased significantly (t=13.824, 11.298 and -6.584, all P<0.001), GLS, GRS and 3D-Strain decreased significantly (t=10.221, -6.237 and -5.674, all P<0.001), LVEDD, LVESD and GAS had no significant difference. Compared with preoperative AS patients, LVEF, GLS, GAS and GCS decreased significantly (t=-2.205, -2.093, -2.034 and -3.152, all P<0.05 or 0.01) at 1 week postoperative, LVEDD, LVESD, IVSD, LVPWD, GRS and 3D-strain had no significant difference at 1 week postoperative; GLS, GRS and 3D-strain increased significantly (t=5.446, -4.923 and -4.388, all P<0.05 or 0.01) at 3 months postoperative, GCS, IVSD and LVPWD decreased significantly (t=-3.988, 4.794 and 4.211, all P<0.05 or 0.01) at 3 months postoperative, LVEDD, LVESD, LVEF and GAS had no significant difference at 3 months postoperative. Compared with AS patients at 1 week postoperative, LVEF, GLS, GRS, GAS and 3D-strain increased significantly (t=-2.631, 7.383, -4.719, 2.923 and -4.154, all P<0.05 or 0.01) at 3 months postoperative, GCS, IVSD and LVPWD decreased significantly (t=-2.109, 4.747 and 4.323, all P<0.05 or 0.01) at 3 months postoperative. But in AS patients at 3 months postoperative, IVSD, LVPWD, GLS and GCS were still higher than those of normal control group (t=9.809, 7.066, 4.752 and -2.553, all P<0.001 or <0.05), LVEDD, LVESD, LVEF, GRS, GAS and 3D-strain had no significant difference. Conclusion The alternation of left ventricular myocardial function have a certain characteristic before and after aortic valve replacement in severe aortic stenosis patients with preserved LVEF, and 3D-STI can evaluate it more accurately. Key words: Three-dimensional speckle tracking; Left ventricular ejection fraction; Aortic valve stenosis; Aortic valve replacement; Myocardium

Invited Commentary

Temporal Trends and Outcomes of Transcatheter Versus Surgical Aortic Valve Replacement for Bicuspid Aortic Valve Stenosis

In adults with valvular aortic stenosis (AS), valve replacement is recommended in the presence of symptoms and severely reduced aortic valve area (AVA).1 In such patients, valve replacement improves symptoms and survival, even in the setting of left ventricular (LV) dysfunction. LV dysfunction in severe AS is usually due to afterload mismatch; valve replacement relieves the afterload excess imposed by the stenotic valve and improves LV performance. 2 However, a subset of patients with “ severe” AS, LV dysfunction, and low-transvalvular gradient has been reported to have a relatively high operative mortality and poor prognosis.2–4⇓⇓ This clinical scenario has been termed “low-flow, low-gradient AS.” Accurate assessment of AVA in such patients is difficult because (1) calculated AVA is directly proportional to forward stroke volume, and (2) the Gorlin constant varies at low-flow states. 5–7⇓⇓ Some patients with low-flow, low-gradient AS have a reduced AVA as a result of inadequate forward stroke volume rather than anatomic stenosis, a situation analogous to reduced anterior mitral leaflet excursion in dilated cardiomyopathy where there is not enough forward flow to fully open the valve. For example, Cannon et al 8 showed that some patients with low-gradient AS were found to have only mild AS at surgery despite a Gorlin AVA indicating critical AS. Obviously, surgical therapy is unlikely to benefit such patients because their primary pathology is a cardiomyopathy. On the other hand, patients with severe anatomic AS may benefit from valve replacement despite the increased operative risk associated with a low-flow, low-gradient hemodynamic state. The recent American College of Cardiology/American Heart Association (ACC/AHA) guidelines for managing valvular heart disease recommends hemodynamic evaluation of low-flow, low-gradient AS using dobutamine echocardiography to distinguish patients with fixed anatomic AS from those with flow-dependent (“ relative”) AS in patients with LV …

Requiem for Routine Self-Expanding TAVR Valves? A Commentary on the Comparative Analysis of Evolut PRO Versus Sapien Ultra Valves for Transfemoral Transcatheter Aortic Valve Implantation Registry (OPERA-TAVI)

Aortic valve replacement surgery is the only available treatment option able to improve survival in patients with symptomatic and severe aortic valve stenosis. Without surgical intervention, patients with symptomatic dyspnea and severe aortic valve stenosis have a median survival less than 2 years. In an ideal, patient-centered healthcare system, the decision whether to undergo risky yet potentially life-prolonging surgery should not only reflect judicious application of the evidence of safety and efficacy of the surgery, but it also should be consistent with the patient’s clinical and personal contexts, and their goals, values, and preferences for life and healthcare. Article see p 533 The report by Bach et al1 is the latest in their series of investigations to uncover why cardiac valve replacement surgery is underused among eligible candidates. In this report, they seek explanations among patient, clinician, and hospital-level characteristics and suggest the following hypothesis: clinicians, particularly cardiologists, are making apparently inconsistent judgments as to which patients should be referred to cardiac surgeons for consideration of aortic valve replacement. Among 191 patients with severe aortic valve stenosis who did not undergo cardiac surgery, a cardiologist evaluated 182 (95%), but referred only 57 (30%) to a cardiac surgeon. In this editorial, we will place this finding in the context of the evolving field of shared decision-making and suggest how this focus could improve the quality of care delivered to patients with valvular heart disease. Shared decision making is a 3-step process.2 The first step involves knowledge transfer. In its idealized form, shared decision making requires symmetrical and bidirectional exchange of information between patients and clinicians. This exchange aims to identify and distinguish the available options under consideration, including the option of no treatment. The other 2 steps require the patient and clinician to (1) actively engage in deliberating (ie, …

ImportanceCalcific aortic stenosis (AS) restricts the aortic valve opening during systole due to calcification and fibrosis of either a congenital bicuspid or a normal trileaflet aortic valve. In the US, AS affects 1% to 2% of adults older than 65 years and approximately 12% of adults older than 75 years. Worldwide, AS leads to more than 100 000 deaths annually.ObservationsCalcific AS is characterized by aortic valve leaflet lipid infiltration and inflammation with subsequent fibrosis and calcification. Symptoms due to severe AS, such as exercise intolerance, exertional dyspnea, and syncope, are associated with a 1-year mortality rate of up to 50% without aortic valve replacement. Echocardiography can detect AS and measure the severity of aortic valve dysfunction. Although progression rates vary, once aortic velocity is higher than 2 m/s, progression to severe AS occurs typically within 10 years. Severe AS is defined by an aortic velocity 4 m/s or higher, a mean gradient 40 mm Hg or higher, or a valve area less than or equal to 1.0 cm2. Management of mild to moderate AS and asymptomatic severe AS consists of patient education about the typical progression of disease; clinical and echocardiographic surveillance at intervals of 3 to 5 years for mild AS, 1 to 2 years for moderate AS, and 6 to 12 months for severe AS; and treatment of hypertension, hyperlipidemia, and cigarette smoking as indicated. When a patient with severe AS develops symptoms, surgical aortic valve replacement (SAVR) or transcatheter aortic valve implantation (TAVI) is recommended, which restores an average life expectancy; in patients aged older than 70 years with a low surgical risk, 10-year all-cause mortality was 62.7% with TAVI and 64.0% with SAVR. TAVI is associated with decreased length of hospitalization, more rapid return to normal activities, and less pain compared with SAVR. However, evidence supporting TAVI for patients aged younger than 65 years and long-term outcomes of TAVI are less well defined than for SAVR. For patients with symptomatic severe AS, the 2020 American College of Cardiology/American Heart Association guideline recommends SAVR for individuals aged 65 years and younger, SAVR or TAVI for those aged 66 to 79 years, and TAVI for individuals aged 80 years and older or those with an estimated surgical mortality of 8% or higher.ConclusionsCalcific AS is a common chronic progressive condition among older adults and is diagnosed via echocardiography. Symptomatic patients with severe AS have a mortality rate of up to 50% after 1 year, but treatment with SAVR or TAVI reduces mortality to that of age-matched control patients. The type and timing of valve replacement should be built on evidence-based guidelines, shared decision-making, and involvement of a multidisciplinary heart valve team.

Only 50% of patients with aortic stenosis (AS) and low ejection fraction (EF) improve their contractility after surgical aortic valve replacement (AVR). Long-term prognosis of these patients is strongly correlated to EF recovery after the surgery. The aim of this study was to compare the postoperative left ventricular function recovery in patients with severe AS and reduced EF after AVR and transcatheter aortic valve implantation (TAVI). Twenty-one patients undergoing AVR for severe AS (<1cm²) and reduced EF (<45%) were echocardiographically compared with 31 patients treated with TAVI by conventional and two-dimensional (2D) strain method. TAVI patients were older (83±6 vs. 74±13years, P<0.001), had more comorbidities (Euroscore 26±15% vs. 16±12%, P<0.001) and no differences in ischemic heart disease (16.1% vs. 9.5%, P=0.39). EF was similar in both groups at baseline. Aortic valve area significantly increased (P=0.01) while pressure gradient decreased (P=0.009) after both procedures but TAVI was associated with a better EF recovery compared with AVR at day 7. Regional function assessed by radial 2D strain increased in TAVI group but was transiently deteriorated in AVR patients (P<0.05). Longitudinal as well as circumferential 2D strain progressively increased at follow-up in both groups (P<0.05). EF was similar in both groups at 3-month follow-up. In patients with severe AS and reduced EF, TAVI is associated with faster and better recovery of LV function compared with AVR.

Objective: Mild-to-moderate mitral regurgitation (MR) often coexists with severe aortic stenosis and has been reported to be presented in up to 2/3 patients requiring aortic valve replacement (AVR). MR in patients with aortic stenosis is often functional in nature although organic mitral disease may coexist. Increased afterload and left ventricular remodeling have been implicated to explain the functional MR in patients with aortic valve stenosis. Furthermore, remodeling observed after AVR may impact the outcome of MR postoperatively. However, the clinical outcome of persistent MR after AVR is uninvestigated. On the other hand, concomitant replacement of the aortic and mitral valves is associated with an increased morbidity and mortality compared to an isolated AVR. This study aims to assess the change in MR severity following AVR for severe AS and to determine the factors associated with the MR improvement. Material and Methods: The clinical and surgical characteristics were compared in a cohort of 149 consecutive patients who underwent isolated AVR in Aleppo University Hospital for cardiac surgery. Results: Non-severe functional mitral valve regurgitation was detected prior to surgery in 25.5% of the patients. These patients were older (p = 0.007), more often had ventricular dysfunction (p = 0.02) and pulmonary hypertension (p = 0.04), and had been admitted more frequently for heart failure (0.008), with fewer of them conserving sinus rhythm (p = 0.003). In addition, the pre-surgery existence of MR was associated with greater morbidity and mortality (5.2% vs. 3.7%; p = 0.025). The MR disappeared or improved prior to hospital discharge in 56.2% and 15.6%, respectively. Independent factors predicting this improvement were the presence of coronary lesions (OR 3.74, p = 0.03), and the absence of diabetes (OR 0.28, p = 0.005) as well as pulmonary hypertension (OR 0.34, p = 0.01). Conclusion: In this study, MR decreased or disappeared in a high percentage of patients after AVR surgery. Independent factors predicting this improvement included the presence of prior coronary lesions, although the improvement is influenced by the diabetic status of the patient, as well as pulmonary hypertension.