Diagnosing heart failure in aortic valve stenosis

OBJECTIVE: In aortic valve stenosis (AS), heart failure (HF) omens a high risk of death and is an indication for prompt valve replacement. We studied whether its detection can be facilitated by measuring plasma N-terminal B-type natriuretic peptide (Nt-BNP) or by estimating pulmonary capillary wedge pressure (PCWP) using echocardiography. DESIGN AND SETTING: A cross-sectional cohort study in a university hospital. SUBJECTS AND METHODS: We studied 137 consecutive adult patients referred to our unit for invasive evaluation of isolated AS. All patients underwent cardiac catheterization, measurement of plasma Nt-BNP and estimation of PCWP by Doppler echocardiography of transmitral and pulmonary venous flow velocities. The final diagnosis of HF was based on the combined criteria of dyspnoea on ordinary effort and PCWP >14 mmHg at cardiac catheterization. The performance of Nt-BNP and the PCWP estimate in the detection of HF were studied using receiver operating characteristic (ROC) analysis. RESULTS: Totally 42 patients had HF. A cardiologist's clinical diagnosis of HF had high specificity (94%) but poor sensitivity (66%). With an optimized cut-off point, plasma Nt-BNP had moderate sensitivity (77%) and specificity (79%) for HF; the ROC area was 0.83. The echocardiographic PCWP estimate classified 90% of patients correctly as having normal or truly elevated (>14 mmHg) PCWP. Its sensitivity and specificity for the diagnosis of HF were 80 and 95% respectively; the ROC area was 0.88. With a cut-off point of 12 mmHg, the sensitivity of the PCWP estimate was 85% and specificity, 88%. CONCLUSION: The recognition of HF in patients with AS can be improved by estimating PCWP using Doppler echocardiography of transmitral and pulmonary venous flow velocities.     

Congenital severe aortic stenosis with congestive heart failure in late childhood and adolescence: effect on left ventricular function after balloon valvuloplasty.

Left ventricular (LV) dysfunction with congestive heart failure (CHF) resulting from severe congenital aortic stenosis (AS) is a well-described condition in infancy, but it is rarely found in older children and adolescents. Aortic valve surgery in such cases may be associated with higher rates of morbidity and mortality. Aortic valve balloon dilatation (AVBD) is a viable alternative, but its effect on LV function has not been evaluated. We describe follow-up results of AVBD in 10 cases of severe congenital AS in older children and adolescents with CHF and LV dysfunction. The ages of these patients ranged from 5 to 18 yr (mean +/- SD: 10.8 +/- 4 yr), and nine were males. The follow-up period after AVBD ranged from 3 mo to 7 yr (mean +/- SD: 2.93 +/- 2.1 yr). Success was achieved in all cases, with no immediate complications. After valvuloplasty, the peak-to-peak systolic gradient declined from 74.7 +/- 30.8 to 33.9 +/- 18.2 mm Hg (P < 0.0001). The cardiac index increased slightly but significantly, from 1.9 +/- 0.27 to 2.2 +/- 0.5 L/min/m(2) (P < 0.015). Hemodynamic improvement was also confirmed by a significant decrease in mean pulmonary artery and pulmonary artery wedge pressures from 41.9 +/- 9 to 32.6 +/- 6.6 and from 25.5 +/- 2.9 to 19.3 +/- 3.4 mm Hg, respectively. The echocardiographically derived left ventricular ejection fraction (LVEF) improved from 21.6 +/- 5. 37% to 31 +/- 6.5% within 24 hr after AVBD, and it further improved in all cases on follow-up. Mean LVEF at last follow-up was 59.4 +/- 11.4%. The Doppler instantaneous peak systolic gradient (IPSG) increased from 37.3 +/- 18.8 to 64.8 +/- 30.7 mm Hg at late follow-up. Significant aortic regurgitation (AR) developed in 20% of patients. The Doppler IPSG across the aortic valve was > 60 mm Hg in five cases on follow-up. Two of these patients underwent another AVBD successfully 4 and 16 mo later, respectively. Aortic valve replacement was done in two patients, one for severe restenosis with mild AR 12 mo after AVBD and another for severe re-restenosis with moderate AR 21 mo after a second AVBD. Severe congenital AS can be associated with LV dysfunction and CHF in late childhood and adolescence. AVBD results in good palliation with improvement in LV function on follow-up.     

Failure of left ventricular hypertrophy to regress after surgery for aortic valve stenosis

BACKGROUND: Regression of left ventricular (LV) hypertrophy usually follows surgery for aortic stenosis (AS); however, a significant number of ventricles remain hypertrophied. The extent of this phenomenon, the reasons for failure to regress, and its significance are unclear. METHODS: We investigated 43 patients before and after aortic valve surgery and divided them into two groups: 30 patients with regression of LV hypertrophy (Group A) and 13 patients without regression (Group B). Preoperative echocardiographic measurements, clinical status, and operative factors were compared between the two groups. The patients were followed up for 42 +/- 22 months for the occurrence of hospitalization for congestive heart failure (CHF) or death. RESULTS: Preoperatively, the two groups were similar except for an excess of patients in New York Heart Association (NYHA) functional Class IV and a greater incidence of old myocardial infarcts in Group B. Postoperatively, Group B patients had larger LVs with decreased systolic function. This was associated with a poor prognosis (23% mortality and 38% CHF vs 0% and 4% for Group A patients, P = 0.0002). Cox regression analysis showed previous myocardial infarction (P < 0.001) and percent mass reduction (P = 0.019) to be independent predictors of CHF or death. CONCLUSIONS: Successful regression of LV mass is difficult to predict before surgery; however, its absence is related strongly to a poor long-term prognosis.     

Changes in left ventricular filling after valve replacement for aortic stenosis

In order to evaluate the short- and long-term effects of aortic valve replacement on the pattern of left ventricular inflow velocity, pulsed wave Doppler analysis was performed in 20 patients with isolated aortic stenosis. Complementary, left ventricular wall thickness was measured, using M-mode echocardiography. One week after operation, left ventricular wall thickness is not changed significantly. The Doppler findings suggest some improvement of left ventricular filling. Six months and 1 year postoperatively, there is a significant, but incomplete regression of left ventricular hypertrophy. Left ventricular filling improved only partially, compared to preoperatively.     

Diagnosis and management of aortic valve stenosis in patients with heart failure

Aortic stenosis (AS) is the most frequent degenerative valvular heart disease in Western countries and its prevalence increases in parallel with the ageing process of the population. Heart failure (HF), defined by the presence of reduced left ventricular ejection fraction, may be present in up to a quarter of patients with severe AS, posing diagnostic and management challenges. The present article reviews the prevalence of HF in severe AS patients, discusses the diagnostic challenges and the advances in multimodality imaging to identify the patients that may benefit from surgical or transcatheter aortic valve replacement, and summarizes the current evidence on management for this group of patients.     

Leakage of cardiac troponin I in aortic valve stenosis

OBJECTIVE: Degeneration and death of cardiomyocytes contribute to the genesis of heart failure (HF) in aortic valve stenosis (AS). We studied whether the ongoing myocyte damage in AS can be detected from circulating cardiac troponin I (cTnI) concentrations. DESIGN AND SETTING: A cross-sectional cohort study in a university hospital. SUBJECTS AND METHODS: We examined 131 adult patients undergoing echocardiography and cardiac catheterization for isolated AS. Blood was sampled from the aortic root and, in a subset of 49 patients, also from the coronary sinus for the determination of cTnI using a sensitive immunoanalysis. RESULTS: Seventy-three patients (56%) had detectable aortic cTnI (> or =5 ng L(-1)) with 30 of them (23% of the total group) having cTnI above the reference limit in healthy subjects (>14 ng L(-1)). Patients with detectable cTnI had a higher prevalence of HF than those with undetectable cTnI (42% vs. 19%, P = 0.004). Plasma cTnI rose from the aorta to the coronary sinus by > or =5 ng L(-1) in 13 of 49 patients with AS (27%) versus in none of 12 control patients free of structural heart disease (P = 0.044). AS patients with transcardiac cTnI gradients > or =5 ng L(-1) had lower left ventricular (LV) ejection fractions than AS patients with gradients <5 ng L(-1) (mean +/- SD, 52 +/- 14% vs. 61 +/- 11%; P = 0.011). CONCLUSIONS: Detectable circulating cTnI is not uncommon in AS and shows a moderate association with the presence of HF. Leakage of cTnI into the coronary sinus associates with impairment of LV systolic function. Monitoring cTnI could provide a means to expose incipient clinical deterioration in AS.     

Outcomes and survival with aortic valve replacement compared with medical therapy in patients with low-, moderate-, and severe-gradient severe aortic stenosis and normal left ventricular ejection fraction

Background: This study determined outcomes and survival with aortic valve replacement (AVR) versus medical therapy in patients with normal left ventricular ejection fraction (LVEF) with severely reduced aortic valve areas (AVA) but nonsevere mean gradients. Methods: We identified 248 aortic stenosis (AS) patients with LVEF ≥ 50% and echocardiographic AVA < 1.0 cm². Group 1 had low‐gradient: <30 mmHg mean gradient; group 2 (moderate: 30 to 40 mm Hg); and group 3 (severe: >40 mm). Results: There were 94, 87, and 67 patients in groups 1, 2, and 3. Incidence of death in groups 1, 2, and 3 were 55%, 39%, and 39% (P not significant). Incidence of AVR in groups 1, 2, and 3 were 23%, 53%, and 49% (P < 0.0001 for group 1 vs. 2; P = 0.0003 for group 1 vs. group 3). Incidence of AVR or death was 71%, 77%, and 76% (P not significant). AVR (hazard ratio = 0.30; 95% CI, 0.18, 0.51; P < 0.0001) and mitral annular calcification (hazard ratio = 2.33; 95% CI, 1.40, 3.88; P = 0.001) were independently associated with time to mortality. Kaplan–Meier curves for time to death did not differ significantly among the three groups. Kaplan–Meier survival curves for patients with and without AVR showed patients in all three groups who underwent AVR had significantly greater survival. Conclusion: Among patients with normal LVEF and AVA < 1.0 cm², overall survival does not differ among those with low‐, moderate‐, or severe‐aortic valve gradients. Survival is significantly improved with AVR, regardless of gradient. (Echocardiography 2011;28:378‐387)     

超声心动图在主动脉瓣狭窄经导管主动脉瓣植入术中的应用价值

目的探讨超声心动图在主动脉瓣狭窄患者经导管主动脉瓣植入术中的作用。方法3例重度主动脉瓣瓣膜狭窄患者接受经导管主动脉瓣人工瓣膜植入术。使用PhilipS iE33型彩色多普勒超声诊断仪,配备经胸探头S5—1和经食道探头S7—2,X7—2t。超声观察内容包括明确主动脉瓣膜病变范围和程度,测量主动脉瓣环前后径,人工瓣膜植入术后瓣膜功能等。结果3例患者经导管主动脉瓣植入术均取得了成功,人工瓣膜位置稳定,常规超声心动图3例患者术前经胸超声心动图与术中经食管超声心动图诊断相符,跨瓣压差较术前明显下降,主动脉瓣瓣上流速明显下降,瓣周漏瞬时反流量平均约1．2mL。结论经导管主动脉瓣人工瓣膜植入术在治疗严重主动脉瓣瓣膜狭窄中方法可行,效果良好;超声心动图在这项工作中具有重要的辅助作用。     

The effect of aortic valve replacement on left ventricular mass assessed by echocardiography.

AIMS: The aim of the study was to investigate whether aortic valve replacement (AVR) has different effects on the left ventricular mass (LVM) in patients with different types of aortic valve disease, i.e. aortic stenosis (AS), aortic regurgitation (AR), or combined disease. METHODS AND RESULTS: We studied 100 patients with AS; (n=57), AR; (n=22), and combined disease; (n=21). Each patient was evaluated before and up to 8.7 years (mean follow-up period 1.42 +/- 1.65 years) after operation by transthoracic echocardiography. LVM was calculated based on echocardiographic parameters. Following AVR, the LVM for the entire group decreased from 373 +/- 145 g to 280 +/- 102 g (P=0.0001). The AS subgroup lost 13.7 +/- 30.7% from the preoperative LVM, compared to 28.8 +/- 24.8% in the AR subgroup (P<0.05) and 23.1 +/- 33.1% in the combined subgroup. The preoperative LVM was higher among patients with AR vs. AS patients (501 +/- 173 g vs. 319 +/- 100 g respectively, P<0.05). The decrease in LVM was significantly higher in patients with preoperative AR compared to AS patients (165 +/- 150 g vs. 58 +/- 96 g, respectively, P<0.05). However, the postoperative LVM remained higher among the former. The only preoperative parameter (of the LVM formula) that was different between AR and AS patients was the left ventricular end diastolic diameter (68 +/- 11 mm vs. 51 +/- 7 mm, respectively, P<0.05). No significant differences were found in wall thickness among the groups studied. Univariate analysis showed that gender (male), type of aortic valve disease (AR vs. AS), and larger prosthetic valve diameter correlated significantly with greater decrease in postoperative LVM. In multivariate analysis comparing the above variables between AS and AR subgroups, only the patient's gender (i.e. male) was identified as an independent predictor of LVM regression. CONCLUSION: Patients with AR have a greater decline in LVM compared with patients with AS following AVR. The postoperative decline in LVM is higher among males and those with larger prosthetic valve diameter.     

Doppler echocardiography markedly underestimates left ventricular stroke work loss in severe aortic valve stenosis.

AIMS: Left ventricular (LV) stroke work loss (SWL) is an index of aortic stenosis (AS) severity based on the energy loss concept. Traditionally known as an invasive measurement, SWL has also been determined noninvasively using Doppler echocardiography. The present work was done to compare the echocardiographic estimate against the standard invasive SWL. METHODS AND RESULTS: We determined SWL in 113 adult patients with AS at cardiac catheterization (mean gradient as percentage of the LV mean systolic pressure) and by Doppler echocardiography (mean gradient as percentage of the sum of systolic cuff blood pressure and mean gradient). SWL averaged 26.5+/-0.6% by echocardiography vs 30.9+/-0.8% by catheterization (p<0.0000001). The underestimation by echocardiography was the worse the higher the invasive SWL was (p<0.00001). Echocardiographic SWL exceeding 25% (previously suggested cutoff) had a sensitivity of 64% and specificity of 74% to identify severe AS (Gorlin valve area<0.5 cm(2)/m(2)). Several patients with severe AS by valve area had echocardiographic SWL suggesting only mild AS. CONCLUSIONS: In AS, echocardiography gives a biased estimate of LV SWL with marked underestimation in severe disease. Echocardiographic SWL may confuse rather than improve the assessment of AS in clinical practice.     

Factors determining early improvement in mitral regurgitation after aortic valve replacement for aortic valve stenosis: a transthoracic and transesophageal prospective study

BACKGROUND: Mitral regurgitation (MR) is frequently associated with aortic stenosis. Previous reports have shown that coexisting mitral insufficiency can potentially regress after aortic valve replacement. HYPOTHESIS: This study sought to assess the frequency and severity of MR before and after aortic valve replacement for aortic stenosis and to define the determinants of its postoperative evolution. METHODS: For this purpose, 30 adult patients referred for aortic valve surgery underwent pre- and postoperative transthoracic and transesophageal echocardiography and color Doppler examination. RESULTS: Mean preoperative left ventricular ejection fraction was 57 +/- 16% and remained unchanged postoperatively. Preoperative MR was usually mild to moderate and correlated with aortic stenosis severity and left ventricular systolic dysfunction. The color Doppler mitral regurgitant jet area significantly decreased during the postoperative period (p = 0.016) as left ventricular loading conditions returned to normal, suggesting an early decrease of the functional part of MR. On the other hand, the mitral regurgitant jet width at the origin remained unchanged. Statistical analysis found pulmonary artery pressure (p = 0.02) an d indexed left ventricular mass (p = 0.009) to be preoperative predictive factors of postoperative MR improvement. Predictive factors of postoperative MR severity were left atrial diameter (p = 0.02), pulmonary artery pressure (p = 0.003), and the presence of mitral calcifications (p = 0.004). CONCLUSION: In our cohort of patients with normal left venticular ejection fraction, the majority of moderate MR, associated with severe aortic stenosis, regresses early after aortic valve replacement. Mitral calcifications and/or left atrial dilation seem to be predictive factors of fixed MR.     

The spectrum of left ventricular filling in severe aortic stenosis

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

Systolic left atrial failure in elderly women with severe aortic stenosis: mitral and pulmonary vein Doppler analysis by transesophageal echocardiography

We studied prospectively 35 elder women aged 65-82 years, with isolated severe symptomatic aortic stenosis, referred for aortic valve surgery. We assessed diastolic function by TEE before and after cardiac surgery, although follow-up data were collected in 26 patients. The examination was performed prior to surgery and 6 months after. The control group consisted of 32 patients referred for TEE. In the preoperative study, the velocities and integrals of the waves in the pulmonary vein flow were similar to the people of their same age, except the A-wave of atrial contraction and the integral of the systolic wave, which were significantly smaller (Control A-wave 26.1 +/- 5.1 vs preoperative A-wave 22.6 +/- 5.6, P = 0.009 and control double product A vel xA dur 2,748 +/- 835 vs preoperative 2,273 +/- 968, P = 0.03; systolic integral 14.6 +/- 3.8 vs 11.3 +/- 4, P = 0.0009). Six months after surgery, the PV flow was similar to the control group except for the wave of atrial contraction, which was significantly smaller but tended to normalization (postoperative A-wave 23.3 +/- 5, P = 0.04 vs control, and postoperative double product A vel x A dur 2460 +/- 893, P = 0.21 vs control). Mitral flow parameters did not change in the preoperative and postoperative period. Left ventricular mass index changed from 166 +/- 54 g/m(2) to 105 +/- 39 g/m(2) (P< 0.0001). The results of this study show that in elderly women with symptomatic severe AS, diastolic function does not change, left ventricular mass reduces, with improvement in symptoms, and the left atrium function, considered by pulmonary vein flow, is preoperative depressed and tends to mild recovery in the postoperative period, suggesting systolic LA failure.     

Isolated supravalvular aortic stenosis with left ventricular diverticulum and cleft mitral valve: Surgical repair in adulthood

Supravalvular aortic stenosis is an uncommon but well characterized congenital narrowing of the ascending aorta above the level of the coronary arteries. It can be a familial disorder, can occur sporadically, or can be associated with Williams syndrome. We are reporting a very rare presentation of supravalvular aortic stenosis with associated left ventricular diverticulum and cleft mitral valve. Repair consisted of resection of the ascending aorta, patch augmentation of the aortic root, and mitral valve repair. Follow-up echocardiography demonstrated normal mitral and aortic valve function and a postoperative three-dimensional computed tomographic scan showed a normal shape of the reconstructed ascending aorta.