The natural history and rate of progression of aortic stenosis

Natural history and clinical burden of moderate aortic stenosis: a systematic review and explorative meta-analysis

AIMS

The mortality risk of patients with moderate aortic stenosis is not well known, but recent studies suggested that it might negatively affect prognosis. We aimed to assess the natural history and clinical burden of moderate aortic stenosis and to investigate the interaction of patients' baseline characteristics with prognosis.

METHODS

Systematic research was conducted on PubMed. The inclusion criteria were inclusion of patients with moderate aortic stenosis; and report of the survival at 1-year follow-up (minimum). Incidence ratios related to all-cause mortality in patients and controls of each study were estimated and then pooled using a fixed effects model. All patients with mild aortic stenosis or without aortic stenosis were considered controls. Meta-regression analysis was performed to assess the impact of left ventricular ejection fraction and age on the prognosis of patients with moderate aortic stenosis.

RESULTS

Fifteen studies and 11 596 patients with moderate aortic stenosis were included. All-cause mortality was significantly higher among patients with moderate aortic stenosis than in controls in all timeframes analysed (all P  < 0.0001). Left ventricular ejection fraction and sex did not significantly impact on the prognosis of patients with moderate aortic stenosis ( P  = 0.4584 and P  = 0.5792), while increasing age showed a significant interaction with mortality (estimate = 0.0067; 95% confidence interval: 0.0007-0.0127; P  = 0.0323).

CONCLUSION

Moderate aortic stenosis is associated with reduced survival. Further studies are necessary to confirm the prognostic impact of this valvulopathy and the possible benefit of aortic valve replacement.

Spatial analysis and factors associated with transcatheter aortic valve implantation in Portugal: a retrospective analysis from 2015 to 2017

OBJECTIVES

To identify the factors associated with transcatheter aortic valve implantation (TAVI) use of TAVI in inpatients with aortic stenosis (AS) in Portugal and its geographical distribution.

METHODS

A quantitative, observational and retrospective study using the Portuguese National Health Service inpatient discharge database from 2015 to 2017. Surgical aortic valve replacement (SAVR) and TAVI procedures were selected using the International Classification of Diseases. First, we mapped the yearly age-standardised rate for each procedure using QGIS. Then, we performed χ² tests, independent t-tests and logistic regressions to study the factors associated with TAVI use.

RESULTS

From 2015 to 2017, 8398 hospitalisations were selected, 88.5% SAVR and 11.5% TAVI. From 2015 to 2017, SAVR use increased in the Northern region and decreased in the Lisbon region, while the opposite was observed for TAVI. TAVI was performed among the most complex (p<0.001) and older patients (the mean (SD) age for SAVR was 70 (±11) years old and 81 (±7) years old for TAVI, p<0.001). The results for the logistic regressions showed that, more recent hospitalisations, being older, living in the Lisbon region and having a higher Charlson Comorbidity Index was associated with an increased likelihood of undergoing TAVI (p<0.001).

CONCLUSIONS

TAVI increased over the years. TAVI is more often performed in more severe patients as an alternative to SAVR with similar discharge outcomes. These results suggest the existence of geographic disparities in the availability and access to healthcare services and technologies.

Long-term prognostic impact of paravalvular leakage on coronary artery disease requires patient-specific quantification of hemodynamics

Transcatheter aortic valve replacement (TAVR) is a frequently used minimally invasive intervention for patient with aortic stenosis across a broad risk spectrum. While coronary artery disease (CAD) is present in approximately half of TAVR candidates, correlation of post-TAVR complications such as paravalvular leakage (PVL) or misalignment with CAD are not fully understood. For this purpose, we developed a multiscale computational framework based on a patient-specific lumped-parameter algorithm and a 3-D strongly-coupled fluid-structure interaction model to quantify metrics of global circulatory function, metrics of global cardiac function and local cardiac fluid dynamics in 6 patients. Based on our findings, PVL limits the benefits of TAVR and restricts coronary perfusion due to the lack of sufficient coronary blood flow during diastole phase (e.g., maximum coronary flow rate reduced by 21.73%, 21.43% and 21.43% in the left anterior descending (LAD), left circumflex (LCX) and right coronary artery (RCA) respectively (N = 6)). Moreover, PVL may increase the LV load (e.g., LV load increased by 17.57% (N = 6)) and decrease the coronary wall shear stress (e.g., maximum wall shear stress reduced by 20.62%, 21.92%, 22.28% and 25.66% in the left main coronary artery (LMCA), left anterior descending (LAD), left circumflex (LCX) and right coronary artery (RCA) respectively (N = 6)), which could promote atherosclerosis development through loss of the physiological flow-oriented alignment of endothelial cells. This study demonstrated that a rigorously developed personalized image-based computational framework can provide vital insights into underlying mechanics of TAVR and CAD interactions and assist in treatment planning and patient risk stratification in patients.

Incidence, risk factors and predictors of cardiovascular mortality for aortic stenosis among patients with diabetes mellitus

AIMS

To find the incidence, risk factors and predictors of cardiovascular (CV) mortality for aortic stenosis (AS) in patients with type 2 diabetes mellitus (T2DM).

METHODS

Between 2014 and 2019, 20,979 patients with T2DM who underwent echocardiography were enrolled for analysis. The mean follow-up period was 34 months. Multiple risk factors and outcomes for patients with and without AS were presented.

RESULTS

AS was present in 776 (3.70%) patients. Age, female, chronic kidney disease, hyperlipidemia, and peripheral arterial disease statistically increased risk of AS. The CV mortality (adjusted hazard ratio [aHR] = 1.97; 95% confidence interval [CI] 1.336 - 2.906, p < 0.001) and risk of hospitalization for heart failure (HHF) (aHR = 1.73, 95% CI 1.442-2.082, p < 0.001) were significantly increased in patients with AS, without significant differences in acute myocardial infarction and stroke. Severity of AS, body mass index (<27 kg/m²), hypertension, hyperuricemia, left ventricular dysfunction (ejection fraction < 50%), and hematocrit (<38%) were significantly associated with increased CV mortality and HHF.

CONCLUSIONS

AS was associated with an increased risk of CV mortality and HHF in patients with T2DM.

Left Ventricular Mechanics Differ in Subtypes of Aortic Stenosis Following Transcatheter Aortic Valve Replacement

Background

Left ventricular (LV) mechanics are impaired in patients with severe aortic stenosis (AS). We hypothesized that there would be differences in myocardial mechanics, measured by global longitudinal strain (GLS) recovery in patients with four subtypes of severe AS after transcatheter aortic valve replacement (TAVR), stratified based upon flow and gradient.

Methods

We retrospectively evaluated 204 patients with severe AS who underwent TAVR and were followed post-TAVR at our institution for clinical outcomes. Speckle-tracking transthoracic echocardiography was performed pre- and post-TAVR. Patients were classified as: (1) normal-flow and high-gradient, (2) normal-flow and high-gradient with reduced LV ejection fraction (LVEF), (3) classical low-flow and low-gradient, or (4) paradoxical low-flow and low-gradient.

Results

Both GLS (−13.9 ± 4.3 to −14.8 ± 4.3, P < 0.0001) and LVEF (55 ± 15 to 57 ± 14%, P = 0.0001) improved immediately post-TAVR. Patients with low-flow AS had similar improvements in LVEF (+2.6 ± 9%) and aortic valve mean gradient (−23.95 ± 8.34 mmHg) as patients with normal-flow AS. GLS was significantly improved in patients with normal-flow (−0.93 ± 3.10, P = 0.0004) compared to low-flow AS. Across all types of AS, improvement in GLS was associated with a survival benefit, with GLS recovery in alive patients (mean GLS improvement of −1.07 ± 3.10, P < 0.0001).

Conclusions

LV mechanics are abnormal in all patients with subtypes of severe AS and improve immediately post-TAVR. Recovery of GLS was associated with a survival benefit. Patients with both types of low-flow AS showed significantly improved, but still impaired, GLS post-TAVR, suggesting underlying myopathy that does not correct post-TAVR.

Imaging Challenges in Patients with Severe Aortic Stenosis and Heart Failure: Did We Find a Way Out of the Labyrinth?

Aortic stenosis (AS) is the most frequent degenerative valvular disease in developed countries. Its incidence has been constantly rising due to population aging. The diagnosis of AS was considered straightforward for a very long time. High gradients and reduced aortic valve area were considered as "sine qua non" in diagnosis of AS until a growing body of evidence showed that patients with low gradients could also have severe AS with the same or even worse outcome. This completely changed the paradigm of AS diagnosis and involved large numbers of parameters that had never been used in the evaluation of AS severity. Low gradient AS patients may present with heart failure (HF) with preserved or reduced left ventricular ejection fraction (LVEF), associated with changes in cardiac output and flow across the aortic valve. These patients with low-flow low-gradient or paradoxical low-flow low-gradient AS are particularly challenging to diagnose, and cardiac output and flow across the aortic valve have become the most relevant parameters in evaluation of AS, besides gradients and aortic valve area. The introduction of other imaging modalities in the diagnosis of AS significantly improved our knowledge about cardiac mechanics, tissue characterization of myocardium, calcium and inflammation burden of the aortic valve, and their impact on severity, progression and prognosis of AS, not only in symptomatic but also in asymptomatic patients. However, a variety of novel parameters also brought uncertainty regarding the clinical relevance of these indices, as well as the necessity for their validation in everyday practice. The aim of this review is to summarize the prevalence of HF in patients with severe AS and elaborate on the diagnostic challenges and advantages of comprehensive multimodality cardiac imaging to identify the patients that may benefit from surgical or transcatheter aortic valve replacement, as well as parameters that may help during follow-up.

The right parasternal window: when Doppler-beam alignment may be life-saving in patients with aortic valve stenosis

: The need for multiple transducer positions, especially from right parasternal windows, is consistently mentioned in the recommendations for the accurate measurement of peak velocities across a stenotic aortic valve, but yet poorly adopted.We performed a subanalysis of the largest prospective series on the right parasternal acoustic windows in patients with aortic stenosis (330 consecutive) to calculate the degree of misalignment and estimate the potential outcome implication of this often-forgotten approach.The right parasternal view was highly feasible with an average estimated misalignment from the apical view of 14 ± 16 degree; in 10 cases, an estimated misalignment >40 degree. Right parasternal assessment (vs. apical alone) provided a significant reclassification from moderate to severe or even very-severe aortic valve stenosis. Considering a wellestablished survival benefit provided by either percutaneous or surgical valve replacement in patients with severe aortic stenosis the reclassification would result in approximately 1 life-year saved for every 30-35 patients in whom parasternal view were effectively utilized.

Speckle tracking echocardiography in severe patient-prosthesis mismatch

BACKGROUND

Although aortic valve replacement (AVR) when successfully performed boasts low mortality rates in selected patients, prosthesis-patient mismatch (PPM) can be found in the majority of these individuals. Limited research is available supporting the benefit of two-dimensional speckle tracking echocardiography (2D-STE) in patients with severe PPM. This study sought to assess myocardial strain using 2D-STE to determine the relationship between subclinical left ventricular (LV) dysfunction and aortic PPM in patients undergoing AVR with preserved LV ejection fraction.

MATERIAL AND METHODS

We retrospectively examined all consecutive patients with isolated AVR who presented to our center from 2005 to 2018. The data of 1086 patients were analyzed. Severe PPM was defined as an indexed effective orifice area of 0.65 cm²/m² or less. As a result of the detailed assessment, 54 patients meeting the eligibility criteria were included in the study. Baseline data were collected and compared between the two groups of patients with severe PPM (n = 27) and those with normofunctional aortic prosthesis valve as a control group (n = 27). All patients underwent baseline echocardiography. Global longitudinal strain (GLS) and global circumferential strain (GCS) were evaluated by 2D-STE.

RESULTS

When compared with controls, patients with severe PPM had significantly decreased GLS (18.6 ± 2.9 vs. 21.4 ± 2.1; p < 0.01) and GCS (17.2 ± 3.6 vs. 21.7 ± 2.1; p < 0.01) values.

CONCLUSION

In addition to standard clinical and echocardiographic parameters, GLS and GCS suggest subclinical dysfunction and have incremental value in patients with severe PPM.

Bovine Pericardium of High Fibre Dispersion Has High Fatigue Life and Increased Collagen Content; Potentially an Untapped Source of Heart Valve Leaflet Tissue

Bioprosthetic heart valves (BHVs) are implanted in aortic valve stenosis patients to replace the native, dysfunctional valve. Yet, the long-term performance of the glutaraldehyde-fixed bovine pericardium (GLBP) leaflets is known to reduce device durability. The aim of this study was to investigate a type of commercial-grade GLBP which has been over-looked in the literature to date; that of high collagen fibre dispersion (HD). Under uniaxial cyclic loading conditions, it was observed that the fatigue behaviour of HD GLBP was substantially equivalent to GLBP in which the fibres are highly aligned along the loading direction. It was also found that HD GLBP had a statistically significant 9.5% higher collagen content when compared to GLBP with highly aligned collagen fibres. The variability in diseased BHV delivery sites results in unpredictable and complex loading patterns across leaflets in vivo. This study presents the possibility of a shift from the traditional choice of circumferentially aligned GLBP leaflets, to that of high fibre dispersion arrangements. Characterised by its high fatigue life and increased collagen content, in addition to multiple fibre orientations, GLBP of high fibre dispersion may provide better patient outcomes under the multi-directional loading to which BHV leaflets are subjected in vivo.

Urea level is an independent predictor of mortality in patients with severe aortic valve stenosis

Introduction

Severe aortic stenosis (AS) is the most common valvular heart disease in the western world. Various factors are related to severe AS prognosis, including chronic kidney disease. The aim of this study was to evaluate the prognostic value of urea level in patients with severe AS.

Methods

We prospectively enrolled 142 patients (79.1±9.4 years, 88 women) with severe AS (mean valve area 0.67± 0.17 cm²). Clinical assessment, blood tests and echocardiography were performed at enrollment and follow up. The patient population was divided into low and high urea level groups, according to the median urea level at enrollment (72 patients, mean urea 35.5±6.2 mg/dL and 70 patients, mean urea 61.1±17.8 mg/dL, respectively). Hundred and twelve patients (79%) underwent aortic valve intervention. The primary endpoint was all-cause and cardiovascular mortality.

Outcomes

During follow-up of 37±19.5 months, 56 (37.1%) patients died, 39 due to cardiovascular causes. In univariate analysis, age, urea level, creatinine, New York Heart Association (NYHA) class and aortic valve intervention were associated with all-cause mortality. However, in multivariate analysis only aortic valve intervention and blood urea were independent predictors of all-cause mortality (HR 0.494; 95% CI 0.226–0.918, P = 0.026 and HR 1.015; 95% CI 1.003–1.029, P = 0.046 respectively). Urea level, NYHA class and age were also significant predictors of cardiovascular mortality. Whereas, in multivariate analysis, only urea level predicted cardiovascular mortality in these patients (HR 1.017; CI 1.003–1.031 P = 0.019).

Conclusions

Blood urea, a generally readily available and routinely determined marker of renal function, is an independent prognostic factor in patients with severe AS.

Coronary Microcirculation in Aortic Stenosis

Aortic stenosis is a heterogeneous disorder. Variations in the pathological and physiological responses to pressure overload are incompletely understood and generate a range of flow and pressure gradient patterns, which ultimately cause varying microvascular effects. The impact of cardiac-coronary coupling depends on these pressure and flow effects. In this article, we explore important concepts concerning cardiac physiology and the coronary microcirculation in aortic stenosis and their impact on myocardial remodeling, aortic valve flow patterns, and clinical progression.

Multidisciplinary transcatheter aortic valve replacement heart team programme improves mortality in aortic stenosis

Objectives

To analyse the effect of the implementation of a transcatheter aortic valve replacement (TAVR) and multidisciplinary heart team programme on mortality in severe aortic stenosis (AS).

Methods

A retrospective, observational cohort study was performed using the echocardiography, cardiothoracic surgery and TAVR databases between 1 January 2006 and 31 December 2016. Outcomes were compared between the pre- and post-TAVR programme eras in a tertiary referral centre providing transcatheter and surgical interventions for AS.

All-cause mortality within 5 years from diagnosis was determined for 3399 patients with echocardiographically defined severe AS.

Results

Of 3399 patients, there were 210 deaths (6.2%) at 30 days and 1614 deaths (47.5%) at 5 years.

Overall, patients diagnosed in the post-TAVR programme era were older, with a lower ejection fraction and more severe AS, but were less comorbid.

Among 705 patients undergoing intervention, those in the post-TAVR programme era were older, with a lower ejection fraction and more severe AS but no significant differences in comorbidities.

Using an inverse probability weighted cohort and a Cox proportional hazards model, a significant mortality benefit was noted between eras alone (HR=0.86, 95% CI 0.77 to 0.97, p=0.015). When matching for age, comorbidities and valve severity, this benefit was more evident (HR=0.82, 95% CI 0.73 to 0.92, p=0.001).

After adjusting for the presence of aortic valve intervention, a significant benefit persisted (HR=0.84, 95% CI 0.75 to 0.95, p=0.005).

Conclusion

The implementation of a TAVR programme is associated with a mortality benefit in the population with severe AS, independent of the expansion of access to intervention.

Management of Less-Than-Severe Aortic Stenosis During Coronary Bypass: A Systematic Review and Meta-Analysis

OBJECTIVE

The management of concomitant mild-to-moderate aortic stenosis (AS) at the time of coronary artery bypass graft (CABG) is controversial. Here we perform a systematic review and meta-analysis of CABG and aortic valve replacement (AVR) versus CABG alone in patients with mild-moderate AS.

METHODS

We searched MEDLINE and EMBASE databases until July 2018 for studies comparing CABG & AVR versus CABG in patients with mild-moderate AS undergoing coronary bypass. Data were extracted by 2 independent investigators. The main outcomes were operative mortality, long-term survival, and reintervention for AS.

RESULTS

There were 6 unmatched retrospective observational studies with 1,172 patients (median follow-up 4.7 [interquartile range: 4.3 to 5.3] years). Patients undergoing CABG & AVR had less severe coronary artery disease. There were no differences in operative mortality (relative risk [RR]: 1.07; 95% CI, 0.59 to 1.94; P = 0.8). CABG & AVR was associated with greater incidence of stroke, bleeding, renal failure, and mediastinitis. At median follow-up of 5 years, there was no difference in long-term mortality (incidence rate ratio [IRR]:1.44; 95% CI, 0.83 to 2.51; P = 0.19), but CABG & AVR was associated with 73% lower risk of reoperation for AS (n = 13/485 versus n = 71/702; IRR: 0.27; 95% CI, 0.14 to 0.51; P < 0.001).

CONCLUSIONS

In patients undergoing CABG with mild-moderate AS, combining AVR with CABG was associated with no difference in operative mortality but with increased risk of stroke, bleeding, renal failure, and mediastinitis. Long-term mortality was not different, but a risk of reoperation for AS at 5 years was 73% lower. Given the increasingly wide availability and safety of transcatheter aortic valve replacement (TAVR), one may consider a conservative approach toward concomitant mild-moderate AS.

Transcatheter Aortic Valve Replacements: Current Trends and Future Directions

Since the 1960s when the first aortic surgical aortic valve replacement (SAVR) was performed, continuous growth in the field of valvular technology has occurred. Although SAVR remains a lifesaving procedure, minimally invasive transcatheter aortic valve replacement has revolutionized and expanded aortic valve replacement to patients who were not previously SAVR candidates, increasing their quality of life and survival. Since its introduction in the United States in 2011, the technology and practice have rapidly expanded. Hybrid techniques have been developed that combine surgical access to the vasculature with valvular deployment over transcatheter systems. This literature review aims to describe the differences between the current available valve technologies, review approaches to surgical technique, discuss anesthetic considerations, and look forward to future directions, trends, and challenges.

Progression of calcific aortic valve sclerosis in WHHLMI rabbits

BACKGROUND AND AIMS

Aortic valve stenosis (AS) is the most common valvular heart disease and can be life-threatening. The pathogenesis of aortic valve calcification remains largely unknown, primarily due to the lack of an adequate animal model. The high-cholesterol diet-induced AS model in rabbits is one of the established models, but it has the significant limitation of liver dysfunction leading to low survival rates. We hypothesized that a myocardial infarction-prone Watanabe heritable hyperlipidemic (WHHLMI) rabbit, an animal model of familial hypercholesterolemia and atherosclerosis, is a useful animal model of AS.

METHODS

WHHLMI rabbits, aged 20 months and 30 months (n = 19), and control Japanese White rabbits (n = 4), aged 30 months, were used and evaluated by echocardiography under anesthesia. Pathological evaluation and quantitative analyses by polymerase chain reaction (PCR) were also performed.

RESULTS

The lipid profile was similar between 20 months and 30 months. Two rabbits died due to spontaneous myocardial infarction during the study. Thirty-month-old WHHLMI rabbits exhibited significantly smaller aortic valve area (0.22 ± 0.006 cm²vs. 0.12 ± 0.01 cm², p < 0.05) and higher maximal transvalvular pressure gradient (7.0 ± 0.32 vs. 9.9 ± 0.95 mmHg, p < 0.05) than 20 month-old rabbits. Macroscopic examination of excised aortic valves demonstrated thickened and degenerated valve leaflets at 30 months. Histological evaluation confirmed thickened leaflets with calcified nodules at 30 months. Real-time PCR of resected aortic valve also showed increased expression level of calcification-related molecules including osteopontin, Sox9, Bmp2, RANKL, osteoprotegerin, and Runx2 (p < 0.05 each) in 30-month-old rabbits.

CONCLUSIONS

WHHLMI rabbits may be useful models of early-stage AS in vivo.

Matrix Gla protein negatively regulates calcification of human aortic valve interstitial cells isolated from calcified aortic valves

Calcified aortic valve stenosis (CAS) is a common heart valve disease in elderly people, and is mostly accompanied by ectopic valve calcification. We recently demonstrated that tumor necrosis factor-α (TNF-α) induces calcification of human aortic valve interstitial cells (HAVICs) obtained from CAS patients. In this study, we investigated the role of matrix Gla protein (MGP), a known calcification inhibitor that antagonizes bone morphogenetic protein 2 (BMP2) in TNF-α-induced calcification of HAVICs. HAVICs isolated from aortic valves were cultured, and calcification was significantly induced with 30 ng/mL TNF-α. Gene expression of the calcigenic marker, BMP2, was significantly increased in response to TNF-α, while the gene and protein expression of MGP was strongly decreased. To confirm the role of MGP, MGP-knockdown HAVICs and HAVICs overexpressing MGP were generated. In HAVICs, in which MGP expression was inhibited by small interfering RNA, calcification and BMP2 gene expression were induced following long-term culture for 32 days in the absence of TNF-α. In contrast, HAVICs overexpressing MGP had significantly decreased TNF-α-induced calcification. These results suggest that MGP acts as a negative regulator of HAVIC calcification, and as such, may be helpful in the development of new therapies for ectopic calcification of the aortic valve.

Diabetes mellitus and coronary microvascular function in asymptomatic patients with severe aortic stenosis and nonobstructed coronary arteries

BACKGROUND AND AIM

Coronary flow reserve is impaired in asymptomatic patients with aortic stenosis and has a prognostic value. We investigated whether the type II diabetes mellitus additionally impairs microvascular circulation assessed by coronary flow reserve in patients with asymptomatic severe aortic stenosis, normal left ventricular ejection fraction and nonobstructed coronary arteries.

METHODS

A total of 128 patients, mean age of 66.35 ± 10.51 (58.6% males), with severe aortic stenosis and normal left ventricular ejection fraction were enrolled in this study. Patients with diabetes mellitus, those who were treated for diabetes mellitus or had documentation confirming the diagnosis of diabetes mellitus, were considered. All patients underwent coronary angiography and had no obstructive coronary disease (defined as having no stenosis >50% in diameter), standard transthoracic Doppler-echocardiographic study and adenosine stress transthoracic echocardiography for coronary flow reserve measurement.

RESULTS

Diabetes mellitus was present in 26 patients (20.31%). There was no significant difference in aortic stenosis severity between diabetic and non-diabetic patients [aortic valve area (0.81 ± 0.18 vs 0.85 ± 0.15 cm(2)) and Vmax (4.20 ± 0.57 vs 4.21 ± 0.48 m/s)]. Mean coronary flow reserve in diabetic patients was 1.98 ± 0.48, while mean coronary flow reserve in non-diabetic patients was 2.64 ± 0.54 (p < 0.01). Diabetes mellitus was independent predictor of coronary flow reserve [B = -0.636, 95% confidence interval (-0.916 to -0.368), p < 0.001].

CONCLUSION

Diabetes mellitus additionally impairs coronary microvascular function in asymptomatic patients with severe aortic stenosis and nonobstructed coronary arteries.

Exercise stress echocardiography with tissue Doppler imaging in risk stratification of mild to moderate aortic stenosis

BACKGROUND

Patients with mild to moderate aortic stenosis (AS) seem to have a worse outcome than commonly expected. Early identification of subjects who may develop a rapid disease progression or cardiovascular events is critical in order to apply adequate risk management.

STUDY DESIGN

Observational prospective single-centre study.

OBJECTIVE

To determine the prognostic role of exercise stress echocardiography (ESE) in patients with mild and moderate asymptomatic AS.

PATIENTS

Ninety consecutive patients (mean age 74 ± 12 years) with isolated mild and moderate AS were enrolled into the study protocol over a 20 months period. Follow-up time was 12 months.

METHODS

A complete echocardiographic study with tissue Doppler imaging (TDI) was performed at baseline and during semi-supine symptom-limited exercise test to evaluate: (1) the occurrence of symptoms, (2) ST segment changes, (3) transaortic pressure gradient, (4) the E/A ratio, (5) the E/e' ratio and (6) the systolic pulmonary artery pressure.

MAIN OUTCOME MEASURES

During the 1 year follow-up time, we evaluated the occurrence of adverse cardiac events, defined as any of the following: (1) cardio-vascular hospitalization; (2) requirement for aortic valve replacement; (3) cardiac death.

RESULTS

During follow-up, three patients died, 11 underwent aortic valve replacement and 26 had cardiovascular hospitalizations. On univariate analysis, patients who exhibited symptoms during exercise (HR 2.93, p = 0.003); the occurrence of a ≥ 2 mm exercise-induced ST segment depression (HR 3.12, p = 0.001); a ≥ 15 mmHg increase in mean transaortic pressure gradient during exercise (HR 2.77, p = 0.001); a ≥ 50 mmHg exercise-induced increase in systolic pulmonary artery pressure (HR 2.90, p = 0.009); an exercise-induced pseudo-normalization of the E/A ratio (E/A ≥ 1) (HR 7.50, p = 0.0001) and, particularly, a ≥ 15 exercise-induced increase in the E/e' ratio (HR 7.69, p = 0.0001) had a significantly higher risk of cardiac events during the follow-up time. On multivariate analysis, only the latter covariate (HR 6.04, p = 0.009) was independently associated with adverse cardiac events.

CONCLUSIONS

A ≥ 15 stress-induced increase in E/e' ratio is highly predictive of cardiac events in patients with mild to moderate AS. Assessment of diastolic function using TDI during ESE provides additional prognostic information in such patients.

Causes of death and mortality and evaluation of prognostic factors in patients with severe aortic stenosis in an aging society

BACKGROUND

Severe aortic stenosis (AS) is now predominantly a disease of the elderly, with significant mortality and morbidity. In order to investigate the burden of severe AS in the current population, we assessed mortality, causes of death, clinical event rates, and prognostic factors of patients diagnosed with severe AS.

METHODS

A total of 519 consecutive patients (mean age, 78±9 years) with severe AS (aortic valve area <1.0 cm(2)) were retrospectively analyzed. All-cause mortality and clinical events including aortic valve replacement, heart failure requiring admission, acute coronary syndrome, and syncope were measured as main outcome.

RESULTS

During a median follow-up of 3.5 years, 167 patients (32%) died. Overall survival rates at 1 and 3 years were 86% and 70%, respectively. Of all deaths, 101 (61%) were cardiovascular-related and 56 (33%) were non-cardiovascular. Syncope occurred in only 18 (4%) patients, while heart failure requiring admission occurred in 188 (43%) patients as the most frequent event. Male, severe symptoms (New York Heart Association functional class, III/IV), inactive state, previous history of heart failure, renal insufficiency, hemodialysis treatment, peripheral vascular disease, malignancy, and statin use at enrollment were significantly and independently associated with death among the patients.

CONCLUSIONS

Among the one-third of severe AS patients who died during follow-up, 61% of deaths were cardiovascular-related. Cardiovascular death may be the leading, but not the only, cause of death for contemporary severe AS patients. Factors such as severe symptomatic status, lower daily activity level, and chronic kidney diseases were strong predictive factors of worse survival in this population.

Diagnosis and management of valvular aortic stenosis

Valvular aortic stenosis (AS) is a progressive disease that affects 2% of the population aged 65 years or older. The major cause of valvular AS in adults is calcification and fibrosis of a previously normal tricuspid valve or a congenital bicuspid valve, with rheumatic AS being rare in the United States. Once established, the rate of progression of valvular AS is quite variable and impossible to predict for any particular patient. Symptoms of AS are generally insidious at onset, though development of any of the three cardinal symptoms of angina, syncope, or heart failure portends a poor prognosis. Management of symptomatic AS remains primarily surgical, though transcatheter aortic valve replacement (TAVR) is becoming an accepted alternative to surgical aortic valve replacement (SAVR) for patients at high or prohibitive operative risk.

Transcatheter aortic valve implantation

With the improvement in the overall life expectancy, the incidence of aortic stenosis has been increasing. Although aortic valve replacement is a standard therapy, many patients do not undergo surgery for various reasons, including advanced age or the presence of multiple comorbidities. Transcatheter aortic valve implantation (TAVI) has been proposed as a less invasive and equally effective treatment for inoperable or high-risk symptomatic aortic stenosis. Numerous rigorous global clinical trials, as well as a pivotal clinical trial in Japan, have been conducted. In this review, we provide data on the development of TAVI worldwide and discuss the prospects for TAVI in Japan.

Diagnostic value of NT-proBNP in identifying impaired coronary flow reserve in asymptomatic moderate or severe aortic stenosis

AIM

NT-proBNP has been shown to be a reliable biochemical marker for left ventricular wall stress. The relationship between NT-proBNP and coronary flow reserve (CFR) was evaluated in patients with significant asymptomatic aortic stenosis (AS).

METHODS

A total of 74 patients with moderate or severe AS, mean age 66.68 ± 10.02 years (56.75% males), were enrolled in this prospective study. All patients underwent coronary angiography and had no obstructive coronary disease (defined as having no stenosis >50% in diameter). They had all undergone standard transthoracic Doppler-echo study and adenosine stress transthoracic-echo for CFR measurement and laboratory analysis for NT-proBNP measurement.

RESULTS

The median NT-proBNP value was significantly increased (417.0 pg/ml; interquartile range [IQR]: 176.8-962.2 pg/ml). NT-proBNP was significantly higher in the group with CFR ≤2.5 (median: 549.0 pg/ml; IQR: 311.5-1131.0 pg/ml; as opposed to median: 291.5 pg/ml; IQR: 123.0-636.2 pg/ml; W = 452; p = 0.012). NT-proBNP showed significant negative correlation with CFR (ρ = -0.377, p = 0.001). There was also significant correlation between NT-proBNP and E/E´, S´ and aortic valve resistance. The NT-proBNP value of 334.00 pg/ml was determined as the best cut-off value for the diagnosis of CFR ≤2.5 (area under the curve: 0.67; 95%CI: 0.54-0.79; p < 0.01) and the sensitivity and specificity were 74 and 64%, respectively.

CONCLUSION

Elevated NT-proBNP can indicate patients with impaired CFR in asymptomatic moderate or severe AS patients with preserved ejection fraction and nonobstructive coronary arteries.

Cost effectiveness of transcatheter aortic valve replacement compared to medical management in inoperable patients with severe aortic stenosis: Canadian analysis based on the PARTNER Trial Cohort B findings

OBJECTIVE

The only effective treatment for severe aortic stenosis (AS) is valve replacement. However, many patients with co-existing conditions are ineligible for surgical valve replacement, historically leaving medical management (MM) as the only option which has a poor prognosis. Transcatheter Aortic Valve Replacement (TAVR) is a less invasive replacement method. The objective was to estimate cost-effectiveness of TAVR via transfemoral access vs MM in surgically inoperable patients with severe AS from the Canadian public healthcare system perspective.

METHODS

A cost-effectiveness analysis of TAVR vs MM was conducted using a deterministic decision analytic model over a 3-year time horizon. The PARTNER randomized controlled trial results were used to estimate survival, utilities, and some resource utilization. Costs included the valve replacement procedure, complications, hospitalization, outpatient visits/tests, and home/nursing care. Resources were valued (2009 Canadian dollars) using costs from the Ontario Case Costing Initiative (OCCI), Ontario Ministry of Health and Long-Term Care and Ontario Drug Benefits Formulary, or were estimated using relative costs from a French economic evaluation or clinical experts. Costs and outcomes were discounted 5% annually. The effect of uncertainty in model parameters was explored in deterministic and probabilistic sensitivity analysis.

RESULTS

The incremental cost-effectiveness ratio (ICER) was $32,170 per quality-adjusted life year (QALY) gained for TAVR vs MM. When the time horizon was shortened to 24 and 12 months, the ICER increased to $52,848 and $157,429, respectively. All other sensitivity analysis returned an ICER of less than $50,000/QALY gained.

LIMITATIONS

A limitation was lack of availability of Canadian-specific resource and cost data for all resources, leaving one to rely on clinical experts and data from France to inform certain parameters.

CONCLUSIONS

Based on the results of this analysis, it can be concluded that TAVR is cost-effective compared to MM for the treatment of severe AS in surgically inoperable patients.

The natural history of moderate aortic stenosis in a veteran population

OBJECTIVE

Our objective was to evaluate the natural history of moderate aortic stenosis in veterans--a unique patient population with significant comorbidities.

METHODS

We retrospectively reviewed the records of all patients who underwent echocardiography at a single veterans affairs hospital during 2006. We identified consecutive patients who had moderate aortic stenosis as indicated by a mean transaortic gradient of 25 to 40 mm Hg, peak aortic jet velocity of 3 to 4 m/s, or aortic valve area of 1.0 to 1.5 cm(2). The primary end point was defined as survival without aortic valve replacement.

RESULTS

Of the 104 patients (mean age, 74 ± 10 years), 49% had diabetes, 21% had peripheral vascular disease, 21% were current smokers, 18% had chronic obstructive pulmonary disease, 60% had coronary artery disease, 89% had hypertension, and 31% had a body mass index of 30 kg/m(2) or more. Mean ejection fraction was 49% ± 12%. During the mean follow-up period of 22 months (range, 1-67 months), 30% of patients underwent aortic valve replacement--26% for symptomatic severe aortic stenosis and 4% concomitantly with coronary artery bypass grafting as the primary indicated operation--and 61% died. Event-free survivals were 48%, 24%, and 15% at 1, 3, and 5 years, respectively.

CONCLUSIONS

Our cohort of military veteran patients had significant comorbidities. Event-free survival for such patients who have moderate aortic stenosis is significantly lower than previously reported data suggest. Within this unique group of patients, identifying factors that accelerate the progression of moderate aortic stenosis would help surgeons select patients who may benefit from early aortic valve replacement for moderate aortic stenosis.

Clinical and prognostic implications of atrial fibrillation in patients undergoing transcatheter aortic valve implantation

AIM

To study a cohort of consecutive patients undergoing transcatheter aortic valve implantation (TAVI) and compare the outcomes of atrial fibrillation (AF) patients vs patients in sinus rhythm (SR).

METHODS

All consecutive patients undergoing TAVI in our hospital were included. The AF group comprised patients in AF at the time of TAVI or with history of AF, and were compared with the SR group. Procedural, echocardiographic and follow-up variables were compared. Likewise, the CHA(2)DS(2)-VASC stroke risk score and HAS-BLED bleeding risk score and antithrombotic treatment at discharge in AF patients were compared with that in SR patients.

RESULTS

From a total of 34 patients undergoing TAVI, 17 (50%) were allocated to the AF group, of whom 15 (88%) were under chronic oral anticoagulation. Patients in the AF group were similar to those in the SR group except for a trend (P = 0.07) for a higher logistic EuroSCORE (28% vs 19%), and a higher prevalence of hypertension (82% vs 53%) and chronic renal failure (17% vs 0%). Risk of both stroke and bleeding was high in the AF group (mean CHA(2)DS(2)-VASC 4.3, mean HAS-BLED 2.9). In the AF group, treatment at discharge included chronic oral anticoagulation in all except one case, and in association with an antiplatelet drug in 57% of patients. During a mean follow-up of 11 mo (maximum 32), there were only two strokes, none of them during the peri-procedural period: one in the AF group at 30 mo and one in the SR group at 3 mo. There were no statistical differences in procedural success, and clinical outcome (survival at 1 year 81% vs 74% in AF and SR groups, respectively, P = NS).

CONCLUSION

Patients in AF undergoing TAVI show a trend to a higher surgical risk. However, in our cohort, patients in AF did not have a higher stroke rate compared to the SR group, and the prognosis was similar in both groups.

Differences in cardiovascular risk profile between electrocardiographic hypertrophy versus strain in asymptomatic patients with aortic stenosis (from SEAS data)

Electrocardiograms are routinely obtained in clinical follow-up of patients with asymptomatic aortic stenosis (AS). The association with aortic valve, left ventricular (LV) response to long-term pressure load, and clinical covariates is unclear and the clinical value is thus uncertain. Data from clinical examination, electrocardiogram, and echocardiogram in 1,563 patients in the Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) study were used. Electrocardiograms were Minnesota coded for arrhythmias and atrioventricular and intraventricular blocks; LV hypertrophy was assessed by Sokolow-Lyon voltage and Cornell voltage-duration criteria; and strain by T-wave inversion and ST-segment depression. Degree of AS severity was evaluated by echocardiography as peak aortic jet velocity and LV mass was indexed by body surface area. After adjustment for age, gender, LV mass index, heart rate, systolic and diastolic blood pressures, blood glucose, digoxin, antiarrhythmic drugs, drugs acting on the renin-angiotensin system, diuretics, β blockers and calcium receptor blockers; peak aortic jet velocity was significantly greater in patients with electrocardiographic strain (mean difference 0.13 m/s, p <0.001) and LV hypertrophy by Sokolow-Lyon voltage criteria (mean difference 0.12 m/s, p = 0.004). After similar adjustment, LV mass index was significantly greater in patients with electrocardiographic strain (mean difference 14.8 g/cm(2), p <0.001) and LV hypertrophy by Sokolow-Lyon voltage criteria and Cornell voltage-duration criteria (mean differences 8.8 and 17.8 g/cm(2), respectively, p <0.001 for the 2 comparisons). In multiple comparisons patients with electrocardiographic strain had increased peak aortic jet velocity, blood glucose, and uric acid, whereas patients with LV hypertrophy by Sokolow-Lyon voltage criteria were younger and patients with LV hypertrophy by Cornell voltage-duration criteria more often were women. In conclusion, electrocardiographic criteria for LV hypertrophy and strain are independently associated with peak aortic jet velocity and LV mass index. Moreover, clinical covariates differ significantly between patients with electrocardiographic strain and those with LV hypertrophy by Sokolow-Lyon voltage criteria and Cornell voltage-duration criteria.

Transcatheter aortic valve implantation: Current status and future perspectives

Although surgical aortic valve replacement is the standard therapy for severe aortic stenosis (AS), about one third of patients are considered inoperable due to unacceptable surgical risk. Under medical treatment alone these patients have a very poor prognosis with a mortality rate of 50% at 2 years. Transcatheter aortic valve implantation (TAVI) has been used in these patients, and has shown robust results in the only randomized clinical trial of severe AS treatment performed so far. In this review, we will focus on the two commercially available systems: Edwards SAPIEN valve and CoreValve Revalving system. Both systems have demonstrated success rates of over 90% with 30-d mortality rates below 10% in the most recent transfemoral TAVI studies. Moreover, long-term studies have shown that the valves have good haemodynamic performance. Some studies are currently exploring the non-inferiority of TAVI procedures vs conventional surgery in high-risk patients, and long-term clinical results of the percutaneous valves. In this article we review the current status of TAVI including selection of patients, a comparison of available prostheses, results and complications of the procedure, clinical outcomes, and future perspectives.

Aortic Valve Replacement for Aortic Stenosis and Concomitant Coronary Artery Bypass: Long-term Outcomes and Predictors of Mortality

Background

We evaluated the surgical results and predictors of long-term survival in patients who underwent coronary artery bypass grafting (CABG) at the time of an aortic valve replacement (AVR) due to aortic stenosis.

Materials and Methods

Between January 1990 and December 2009, 183 consecutive patients underwent CABG and concomitant aortic valve replacement for aortic stenosis. The mean follow-up period was 59.8±3.3 months and follow-up was possible in 98.3% of cases. Predictors of mortality were determined by Cox regression analysis.

Results

There were 5 (2.7%) in-hospital deaths. Follow-up of the in-hospital survivors documented late survival rates of 91.5%, 74.8%, and 59.6% at 1, 5, and 10 postoperative years, respectively. Age (p<0.001), a glomerular filtration rate (GFR) less than 60 mL/min (p=0.006), and left ventricular (LV) mass (p<0.001) were significant predictors of mortality in the multivariate analysis.

Conclusion

The surgical results and long-term survival of aortic valve replacement with concomitant CABG in patients with aortic stenosis and coronary artery disease were acceptable. Age, a GFR less than 60 mL/min, and LV mass were significant predictors of mortality.

In Vitro Investigation of the Impact of Aortic Valve Stenosis Severity on Left Coronary Artery Flow

Patients with aortic valve stenosis (AS) may experience angina pectoris even if they have angiographically normal coronary arteries. Angina is associated with a marked increase in the risk of sudden death in AS patients. Only a few in vitro models describing the interaction between the left ventricular and aortic pressures, and the coronary circulation have been reported. These models were designed for specific research studies and they need to be improved or modified when other specific studies are required. Consequently, we have developed an in vitro model that is able to mimic the coronary circulation in presence of aortic stenosis. First, we have validated the model under physiological conditions. Then, we have examined and quantified the hemodynamic effects of different degrees of AS (from normal to severe AS) on the coronary flow using a model of the normal left coronary artery. In the coronary in vitro model without AS (normal valve), the amplitude and shape of coronary flow were similar to those observed in in vivo measurements obtained under physiological conditions, as described by Hozumi et al. (1998, “Noninvasive Assessment of Significant Left Anterior Descending Coronary Artery Stenosis by Coronary Flow Velocity Reserve With Transthoracic Color Doppler Echocardiography,” Circulation, 97, pp. 1557–1562). The presence of an AS induced an increase in the maximum and mean coronary flow rates (97% and 73%, respectively, for a very severe AS). Furthermore, when AS was very severe, a retrograde flow occurred during systole. This study allowed us to validate our coronary in vitro model under physiological conditions, both in the absence and presence of AS. These changes could explain the fact that even if patients have angiographically normal epicardial coronary arteries, we can observe the occurrence of angina pectoris in these patients in the presence of an AS.

[Transcatheter aortic valve implantation: surgeon's view]

BACKGROUND AND PURPOSE

The technology of catheter- based aortic valve implantation is a new, less invasive therapeutic option for patients with symptomatic high-grade aortic stenosis. The present paper aims to demonstrate that optimal therapy should be provided by a multidisciplinary team consisting of cardiac surgeons, cardiologists and cardioanesthesiologists in a hybrid suite.

PATIENTS AND METHODS

From June 2007 to April 2009, 234 patients have been treated by transcatheter aortic valve implantation through different access sites (n = 168 femoral artery, n = 56 left ventricular apex, n = 7 subclavian artery, n = 3 ascending aorta) at the German Heart Center Munich, Germany. An algorithm for the choice of the most appropriate access site for the individual patient was established.

RESULTS

The 30-day mortality was 11.2% in this high-risk patient cohort. A certain number of periprocedural complications required surgical management. There was a considerable clinical improvement of the patients 6 months after the procedure.

CONCLUSION

Integrating the new methods of aortic valve implantation into a cardiac surgery program, all kinds of surgical and interventional treatment options may be offered to the patient with aortic stenosis by one multidisciplinary team. A qualified and safe performance of transcatheter aortic valve implantation and the management of potential complications require the presence of a hybrid suite.

New concepts in valvular hemodynamics: implications for diagnosis and treatment of aortic stenosis

Aortic valve stenosis (AS) is the third-most frequent heart disease after coronary artery disease and arterial hypertension, and it is associated with a high incidence of adverse outcomes. Recent data support the notion that AS is not an isolated disease uniquely limited to the valve. Indeed, AS is frequently associated with abnormalities of the systemic arterial system, and, in particular, with reduced arterial compliance, which may have important consequences for the pathophysiology and clinical outcome of this disease. Moreover, AS may also be associated with left ventricular systolic dysfunction and reduced transvalvular flow rate, which pose important challenges with regards to diagnostic evaluation and clinical decision making in AS patients. Hence, the assessment of AS severity, as well as its therapeutic management, should be conducted with the use of a comprehensive evaluation that includes not only the aortic valve, but also the systemic arterial system and the left ventricle because these three entities are tightly coupled from both a pathophysiological and a hemodynamic standpoint.

Impairment of coronary flow reserve in aortic stenosis

Coronary flow reserve (CFR) is markedly reduced in patients with severe aortic valve stenosis (AS), but the exact mechanisms underlying this impairment of CFR in AS remain unclear. Reduced CFR is the key mechanism leading to myocardial ischemia symptoms and adverse outcomes in AS patients. The objective of this study was to develop an explicit mathematical model formulated with a limited number of parameters that describes the effect of AS on left coronary inflow patterns and CFR. We combined the mathematical V3 (ventricular-valvular-vascular) model with a new lumped-parameter model of coronary inflow. One thousand Monte-Carlo computational simulations with AS graded from mild up to very severe were performed within a wide range of physiological conditions. There was a good agreement between the CFR values computed with this new model and those measured in 24 patients with isolated AS ( r = 0.77, P < 10−4). A global sensitivity analysis showed that the valve effective orifice area (EOA) was the major physiological determinant of CFR (total sensitivity index = 0.87). CFR was markedly reduced when AS became severe, i.e., when EOA was <1.0 cm2, and was generally exhausted when the EOA was <0.5–0.6 cm2. The reduction of CFR that is associated with AS can be explained by the concomitance of 1) reduced myocardial supply as a result of decreased coronary perfusion pressure, and 2) increased myocardial metabolic demand as a result of increased left ventricular workload.

Review: Does lowering cholesterol have an impact on the progression of aortic stenosis?

Several studies suggest that atherosclerotic disease is not a focal disease restricted to culprit lesions in the intima of the arterial wall, but seems to act as a general disease affecting the entire cardiovascular system. Evolving research has lately focused on the atherosclerotic component in calcific aortic stenosis (AS) as it seems that the valve is affected in a pattern similar to that of the vasculature. The hope is therefore, that we someday in the management of patients with calcific AS can apply some of the same treatment strategies as in atherosclerotic vascular disease. This article reviews the pathophysiological mechanisms of calcific AS, reviews current clinical trials of statin use in aortic stenosis and reports on on-going trials, evaluating whether cholesterol lowering therapy can slow disease progression in different populations. Finally, we review if computerized tomography, biomarkers, and clinical characteristics such as left ventricular ejection fraction, can be useful in stratifying patients to potential benefit of statin therapy.

Percutaneous implantation of the first repositionable aortic valve prosthesis in a patient with severe aortic stenosis

OBJECTIVES AND BACKGROUND

Percutaneous aortic valve replacement is a new less-invasive alternative for high-risk surgical candidates with aortic stenosis. However, the clinical experience is still limited, and the currently available 'first-generation devices' revealed technical shortcomings, such as lack of repositionability and presence of paravalvular leakages. We report the first-in-man experience with the new self-expanding Lotus Valve prosthesis composed of a nitinol frame with implemented bovine pericardial leaflets which is designed to address these issues, being repositionable and covered by a flexible membrane to seal paravalvular gaps. We implanted this prosthesis in a 93-year old patient presenting with severe symptomatic aortic stenosis (valve area: 0.6 cm(2)). Surgical valve replacement had been declined due to comorbidities.

METHODS AND RESULTS

We used a retrograde approach for insertion of the 21-French Lotus catheter loaded with the valve prosthesis via surgical cut-down to the external iliac artery. Positioning of the valve was guided by transesophageal echo and supra-aortic angiograms. The prosthesis was successfully inserted and deployed within the calcified native valve. Echocardiography immediately after device deployment showed a significant reduction of the transaortic mean pressure gradient (32 to 9 mmHg; final valve area 1.7 cm(2)) without evidence of residual aortic regurgitation. The postprocedural clinical status improved from NYHA-IV to NYHA-II. These results remained unchanged up to the 3 month follow-up.

CONCLUSIONS

Successful percutaneous aortic valve replacement can be performed using the new self-expanding and repositionable Lotus valve for treatment of high-risk patients with aortic valve stenosis. Further studies are mandatory to assess device safety and efficacy in larger patient populations.

Valvular heart diseases

Patients who have valvular heart disease coming for surgery present many challenges to the anesthesiologist. Over the past 3 decades there has been a persistent improvement in our understanding of the pathophysiology of valvular heart disease and in the surgical techniques for correcting it. With the development of efficient and safe noninvasive monitoring of cardiac function, new surgical techniques, better designs of prosthetic valves, and the development of useful guidelines for choosing the proper timing of surgical intervention, patients who have valvular disease with varying physiology can be encountered in the perioperative period. The perioperative physician has to be aware of the varying effects of hemodynamic variables on this subpopulation of patients.