Jean G. Dumesnil

Recommendations for Evaluation of Prosthetic Valves With Echocardiography and Doppler Ultrasound. A Report From the American Society of Echocardiography's Guidelines and Standards Committee and the Task Force on Prosthetic Valves, Developed in Conjunction With the American College of Cardiology Cardiovascular Imaging Committee, Cardiac Imaging Committee of the American Heart Association

A Report From the American Society of Echocardiography’s Guidelines and Standards Committee and the Task Force on Prosthetic Valves, Developed in Conjunction With the American College of Cardiology Cardiovascular Imaging Committee, Cardiac Imaging Committee of the American Heart Association, the European Association of Echocardiography, a registered branch of the European Society of Cardiology, the Japanese Society of Echocardiography and the Canadian Society of Echocardiography, Endorsed by the American College of Cardiology Foundation, American Heart Association, European Association of Echocardiography, a registered branch of the European Society of Cardiology, the Japanese Society of Echocardiography, and Canadian Society of Echocardiography

Paradoxical Low-Flow, Low-Gradient Severe Aortic Stenosis Despite Preserved Ejection Fraction Is Associated With Higher Afterload and Reduced Survival

Background— Recent studies and current clinical observations suggest that some patients with severe aortic stenosis on the basis of aortic valve area may paradoxically have a relatively low gradient despite the presence of a preserved left ventricular (LV) ejection fraction. The objective of the present study was to document the prevalence, potential mechanisms, and clinical relevance of this phenomenon. Methods and Results— We retrospectively studied the clinical and Doppler echocardiographic data of 512 consecutive patients with severe aortic stenosis (indexed aortic valve area ≤0.6 cm2 · m−2) and preserved LV ejection fraction (≥50%). Of these patients, 331 (65%) had normal LV flow output defined as a stroke volume index >35 mL · m2, and 181 (35%) had paradoxically low-flow output defined as stroke volume index ≤35 mL · m−2. When compared with normal flow patients, low-flow patients had a higher prevalence of female gender (P<0.05), a lower transvalvular gradient (32±17 versus 40±15 mm Hg; P<0.001), a lower LV diastolic volume index (52±12 versus 59±13 mL · m−2; P<0.001), lower LV ejection fraction (62±8% versus 68±7%; P<0.001), a higher level of LV global afterload reflected by a higher valvulo-arterial impedance (5.3±1.3 versus 4.1±0.7 mm Hg · mL−1 · m−2; P<0.001) and a lower overall 3-year survival (76% versus 86%; P=0.006). Only age (hazard ratio, 1.04; 95% CI, 1.01 to 1.08; P=0.025), valvulo-arterial impedance >5.5 mm Hg · mL−1 · m−2 (hazard ratio, 2.6; 95% CI, 1.2 to 5.7; P=0.017), and medical treatment (hazard ratio, 3.3; 95% CI, 1.8 to 6.7; P=0.0003) were independently associated with increased mortality. Conclusion— Patients with severe aortic stenosis may have low transvalvular flow and low gradients despite normal LV ejection fraction. A comprehensive evaluation shows that this pattern is in fact consistent with a more advanced stage of the disease and has a poorer prognosis. Such findings are clinically relevant because this condition may often be misdiagnosed, which leads to a neglect and/or an underestimation of symptoms and an inappropriate delay of aortic valve replacement surgery.

Hemodynamic and clinical impact of prosthesis–patient mismatch in the aortic valve position and its prevention ☆

Prosthesis-patient mismatch is present when the effective orifice area of the inserted prosthetic valve is less than that of a normal human valve. This is a frequent problem in patients undergoing aortic valve replacement, and its main hemodynamic consequence is the generation of high transvalvular gradients through normally functioning prosthetic valves. The purposes of this report are to present an update on the concept of aortic prosthesis-patient mismatch and to review the present knowledge with regard to its impact on hemodynamic status, functional capacity, morbidity and mortality. Also, we propose a simple approach for the prevention and clinical management of this phenomenon because it can be largely avoided if certain simple factors are taken into consideration before the operation.

Impact of Valve Prosthesis-Patient Mismatch on Short-Term Mortality After Aortic Valve Replacement

Background—The prosthesis used for aortic valve replacement (AVR) can be too small in relation to body size, thus causing valve prosthesis-patient mismatch (PPM) and abnormally high transvalvular pressure gradients. This study examined if there is a relation between PPM and short-term mortality after operation. Methods and Results—The indexed valve effective orifice area (EOA) was estimated for each type and size of prosthesis being implanted in 1266 consecutive patients and used to define PPM as not clinically significant if >0.85 cm2/m2, as moderate if >0.65 cm2/m2 and ≤0.85 cm2/m2, and as severe if ≤0.65 cm2/m2; it was correlated with 30-day mortality and compared with other relevant variables. Moderate or severe PPM was present in 38% of patients. Thirty-day mortality was 4.6% (58/1266 patients) and the strongest independent predictors in multivariate analysis were left ventricular ejection fraction <40% (P =0.007), infectious endocarditis (P =0.002), emergent/salvage operation (P =0.002), cardiopulmonary bypass time >120 minutes (P =0.001), and PPM (P =0.003). Relative risk of mortality was increased 2.1-fold (95% confidence interval, 1.2 to 3.7) in patients with moderate PPM and 11.4-fold (4.4 to 29.5) in those with severe PPM. Moreover, risk of mortality for every category of PPM was higher in patients with a left ventricular ejection fraction <40% as compared with ≥40% (nonsignificant PPM, 2.7 versus 1.0; moderate PPM, 7.1 versus 1.8; severe PPM, 77.1 versus 11.3). Conclusion—PPM is a strong and independent predictor of short-term mortality among patients undergoing AVR, and its impact is related both to its degree of severity and the status of left ventricular function. In contrast to other risk factors, moderate-severe PPM can be largely avoided with the use of a prospective strategy at the time of operation.

Effect of Lipid Lowering With Rosuvastatin on Progression of Aortic Stenosis Results of the Aortic Stenosis Progression Observation: Measuring Effects of Rosuvastatin (ASTRONOMER) Trial

Background— Aortic stenosis (AS) is an active process with similarities to atherosclerosis. The objective of this study was to assess the effect of cholesterol lowering with rosuvastatin on the progression of AS. Methods and Results— This was a randomized, double-blind, placebo-controlled trial in asymptomatic patients with mild to moderate AS and no clinical indications for cholesterol lowering. The patients were randomized to receive either placebo or rosuvastatin 40 mg daily. A total of 269 patients were randomized: 134 patients to rosuvastatin 40 mg daily and 135 patients to placebo. Annual echocardiograms were performed to assess AS progression, which was the primary outcome; the median follow-up was 3.5 years. The peak AS gradient increased in patients receiving rosuvastatin from a baseline of 40.8±11.1 to 57.8±22.7 mm Hg at the end of follow-up and in patients with placebo from 41.6±10.9 mm Hg at baseline to 54.8±19.8 mm Hg at the end of follow-up. The annualized increase in the peak AS gradient was 6.3±6.9 mm Hg in the rosuvastatin group and 6.1±8.2 mm Hg in the placebo group (P=0.83). Treatment with rosuvastatin was not associated with a reduction in AS progression in any of the predefined subgroups. Conclusion— Cholesterol lowering with rosuvastatin 40 mg did not reduce the progression of AS in patients with mild to moderate AS; thus, statins should not be used for the sole purpose of reducing the progression of AS. Clinical Trial Registration Information— URL: http://www.controlled-trials.com/. Clinical trial registration number: ISRCTN 32424163.

Prosthetic Heart Valves Selection of the Optimal Prosthesis and Long-Term Management

The introduction of valve replacement surgery in the early 1960s has dramatically improved the outcome of patients with valvular heart disease. Approximately 90 000 valve substitutes are now implanted in the United States and 280 000 worldwide each year; approximately half are mechanical valves and half are bioprosthetic valves. Despite the marked improvements in prosthetic valve design and surgical procedures over the past decades, valve replacement does not provide a definitive cure to the patient. Instead, native valve disease is traded for “prosthetic valve disease,” and the outcome of patients undergoing valve replacement is affected by prosthetic valve hemodynamics, durability, and thrombogenicity. Nonetheless, many of the prosthesis-related complications can be prevented or their impact minimized through optimal prosthesis selection in the individual patient and careful medical management and follow-up after implantation. The purpose of this article is to provide an overview of the current state of knowledge and future perspectives with regard to optimal prosthesis selection and clinical management after valve implantation. The ideal valve substitute should mimic the characteristics of a normal native valve. In particular, it should have excellent hemodynamics, long durability, high thromboresistance, and excellent implantability. Unfortunately, this ideal valve substitute does not exist, and each of the currently available prosthetic valves has inherent limitations. ### Mechanical Valves Three basic types of mechanical valve design exist: bileaflet, monoleaflet, and caged ball valves (Figure 1A, 1B, and 1C). Figure 1. Different types of prosthetic valves. A, Bileaflet mechanical valve (St Jude); B, monoleaflet mechanical valve (Medtronic Hall); C, caged ball valve (Starr-Edwards); D, stented porcine bioprosthesis (Medtronic Mosaic); E, stented pericardial bioprosthesis (Carpentier-Edwards Magna); F, stentless porcine bioprosthesis (Medtronic Freestyle); G, percutaneous bioprosthesis expanded over a balloon (Edwards Sapien); H, self-expandable percutaneous bioprosthesis (CoreValve). #### Caged Ball Valves Caged ball valves, which consist of a silastic ball with a circular sewing ring and a …

Prosthesis-patient mismatch: definition, clinical impact, and prevention

Prosthesis-patient mismatch (PPM) is present when the effective orifice area of the inserted prosthetic valve is too small in relation to body size. Its main haemodynamic consequence is to generate higher than expected gradients through normally functioning prosthetic valves. This review updates the present knowledge about the impact of PPM on clinical outcomes. PPM is common (20–70% of aortic valve replacements) and has been shown to be associated with worse haemodynamic function, less regression of left ventricular hypertrophy, more cardiac events, and lower survival. Moreover, as opposed to most other risk factors, PPM can largely be prevented by using a prospective strategy at the time of operation.

Paradoxical low flow and/or low gradient severe aortic stenosis despite preserved left ventricular ejection fraction: implications for diagnosis and treatment

Paradoxical low flow, low gradient, severe aortic stenosis (AS) despite preserved ejection fraction is a recently described clinical entity whereby patients with severe AS on the basis of aortic valve area have a lower than expected gradient in relation to generally accepted values. This mode of presentation of severe AS is relatively frequent (up to 35% of cases) and such patients have a cluster of findings, indicating that they are at a more advanced stage of their disease and have a poorer prognosis if treated medically rather than surgically. Yet, a majority of these patients do not undergo surgery likely due to the fact that the reduced gradient is conducive to an underestimation of the severity of the disease and/or of symptoms. The purpose of this article is to review and further analyse the distinguishing characteristics of this entity and to present its implications with regards to currently accepted guidelines for AS severity.

Low-Flow, Low-Gradient Aortic Stenosis With Normal and Depressed Left Ventricular Ejection Fraction

Low-flow, low-gradient (LF-LG) aortic stenosis (AS) may occur with depressed or preserved left ventricular ejection fraction (LVEF), and both situations are among the most challenging encountered in patients with valvular heart disease. In both cases, the decrease in gradient relative to AS severity is due to a reduction in transvalvular flow. The main challenge in patients with depressed LVEF is to distinguish between true severe versus pseudosevere stenosis and to accurately assess the severity of myocardial impairment. Paradoxical LF-LG severe AS despite a normal LVEF is a recently described entity that is characterized by pronounced LV concentric remodeling, small LV cavity size, and a restrictive physiology leading to impaired LV filling, altered myocardial function, and worse prognosis. Until recently, this entity was often misdiagnosed, thereby causing underestimation of AS severity and inappropriate delays for surgery. Hence, the main challenge in these patients is proper diagnosis, often requiring diagnostic tests other than Doppler echocardiography. The present paper proposes to review the diagnostic and therapeutic management specificities of LF-LG AS with and without depressed LV function.

Long-Term Outcomes After Transcatheter Aortic Valve Implantation Insights on Prognostic Factors and Valve Durability From the Canadian Multicenter Experience

OBJECTIVES This study sought to evaluate the long-term outcomes after transcatheter aortic valve implantation (TAVI) in the Multicenter Canadian Experience study, with special focus on the causes and predictors of late mortality and valve durability. BACKGROUND Very few data exist on the long-term outcomes associated with TAVI. METHODS This was a multicenter study including 339 patients considered to be nonoperable or at very high surgical risk (mean age: 81 ± 8 years; Society of Thoracic Surgeons score: 9.8 ± 6.4%) who underwent TAVI with a balloon-expandable Edwards valve (transfemoral: 48%, transapical: 52%). Follow-up was available in 99% of the patients, and serial echocardiographic exams were evaluated in a central echocardiography core laboratory. RESULTS At a mean follow-up of 42 ± 15 months 188 patients (55.5%) had died. The causes of late death (152 patients) were noncardiac (59.2%), cardiac (23.0%), and unknown (17.8%). The predictors of late mortality were chronic obstructive pulmonary disease (hazard ratio [HR]: 2.18, 95% confidence interval [CI]: 1.53 to 3.11), chronic kidney disease (HR: 1.08 for each decrease of 10 ml/min in estimated glomerular filtration rate, 95% CI: 1.01 to 1.19), chronic atrial fibrillation (HR: 1.44, 95% CI: 1.02 to 2.03), and frailty (HR: 1.52, 95% CI: 1.07 to 2.17). A mild nonclinically significant decrease in valve area occurred at 2-year follow-up (p < 0.01), but no further reduction in valve area was observed up to 4-year follow-up. No changes in residual aortic regurgitation and no cases of structural valve failure were observed during the follow-up period. CONCLUSIONS Approximately one-half of the patients who underwent TAVI because of a high or prohibitive surgical risk profile had died at a mean follow-up of 3.5 years. Late mortality was due to noncardiac comorbidities in more than one-half of patients. No clinically significant deterioration in valve function was observed throughout the follow-up period.