A larger aortic annulus causes aortic regurgitation and a smaller aortic annulus causes aortic stenosis in bicuspid aortic valve

A bicuspid aortic valve (BAV) often causes aortic stenosis (AS) or regurgitation (AR). In 54 patients with a BAV (48 +/- 16 years), transthoracic and transesophageal echo were performed to measure aortic annulus diameter (AAD), to evaluate the severity of aortic valve disease (AVD) and to calculate the area eccentricity index (AEI) of a BAV defined as a ratio of the larger aortic cusp area to a smaller aortic cusp area. By multiple linear regression analysis, the severity of AR correlated significantly with the AAD (r = 0.38) and AEI (r = 0.35) (P < 0.05) and that of AS correlated significantly with the AAD (r =-0.40) and AEI (r = 0.34) (P < 0.05). Thirty-six patients showed anteroposteriorly (A-P) located BAVs and 18 patients showed right-left (R-L) located BAVs. The AAD was larger in A-P type than in R-L type (15 +/- 3 vs 13 +/- 2 mm/BSA, P < 0.05) and there was no difference in the age and AEI between the two groups. AR was more severe in A-P type than in R-L type while AS was more severe in R-L type than in A-P type (P < 0.05). Twenty-nine patients showed raphes. The AEI was larger in raphe (+) type than in raphe (-) type (1.83 +/- 0.53 vs 1.51 +/- 0.47, P < 0.05) and there was no difference in the AAD and severity of AVD between the two groups. In conclusion, a BAV with larger aortic annulus or A-P located will tend to cause AR while a BAV with smaller aortic annulus or R-L located will tend to cause AS.     

Is the clinical course of non-rheumatic aortic regurgitation the same as that of rheumatic aortic regurgitation?

To determine whether non-rheumatic (NR) aortic regurgitation (AR) has the same clinical and postoperative courses as rheumatic (R) AR, we performed a retrospective study using pre- and postoperative M-mode echocardiograms in 23 patients who underwent aortic valve replacement (AVR) under myocardial protection with hypothermic cardioplegia. The etiology of AR was diagnosed by two-dimensional echocardiography. The NR-AR group consisted of nine patients including four with aortic valve prolapse (AP) and five with bicuspid valve (BV), and the R-AR group included 14 patients. Patients with preoperative end-diastolic dimensions (EDD) of less than 6.0 cm were excluded from this study. The indication for AVR was NYHA functional class III or severer. The severity of preoperative NYHA functional class was similar among these three groups. During the 18-month follow-up period (range 2-32 months), there were no post-operative deaths nor congestive heart failure. Ages at surgery ranged from 17 to 54 years; 10 (71%) of 14 patients with R-AR were 40 years old or older, while seven (78%) of nine with NR-AR were under 39 years old (p less than 0.05). The pre-operative left ventricular end-diastolic pressure (LVEDP) in patients with BV-AR was highest among these three groups (R-AR: 14.5 +/- 3.9 mmHg, AP-AR: 9.5 +/- 4.1 mmHg, BV-AR: 22.0 +/- 2.7 mmHg, p less than 0.05). There was no significant difference in pre-operative M-mode echocardiographic results, except for the end-systolic dimension (ESD) between R-AR (5.20 +/- 0.55 cm) and BV-AR (4.78 +/- 0.18 cm) (p less than 0.05). The EDD one month after AVR was still abnormal (greater than or equal to 5.4 cm) in seven of the 14 patients with R-AR, and three of the four patients with AP-AR but none of the patients with BV-ARs (p less than 0.05 vs AP-AR). All patients with pre-operative ESD of less than 5.2 cm had normal EDD one month after AVR. In conclusion, the clinical course of NR-AR is different from that of R-AR. Furthermore, AP-AR regresses more differently after AVR than does BV-AR. Therefore, it is important to consider the etiology of chronic AR in determining the timing of surgery.     

Regression of left ventricular hypertrophy during 10 years after valve replacement for aortic stenosis is related to the preoperative risk profile.

BACKGROUND: Previous studies have suggested that regression of hypertrophy may be the underlying determinant of longevity and left ventricular function after valve replacement (AVR) for aortic stenosis (AS). The potential for hypertrophy regression could therefore be related to the preoperative risk profile. METHODS: Ninety-one consecutive patients with AS had a "project" Doppler-echo and radionuclide ventriculography in addition to the standard investigation programme prior to AVR with a disc valve (19-29mm, n=82), a caged ball valve (26-29mm, n=8), or a stented porcine valve (26mm, n=1); 49 (group A) were selected for a serial follow-up study while 42 served as controls (group B). Forty-two group A patients took part in a 1.5-year examination while 47 (26 group A, 21 group B) patients were studied at 10 years. RESULTS: Groups A and B were comparable as regards all pre- and intra-operative data including left ventricular mass index (LVMi). A previously developed preoperative prognostic index (PI) separated the patients into groups with low (n=23), intermediary (n=19) and high risk (n=49) with 10-year survivals of 87%, 58% and 43% (P<0.01). LVMi dropped from 202+/-58g/m(2)preoperatively to 152+/-45g/m(2)(P<0.0001) at 1.5 years, and 139+/-40g/m(2)(P<0.0001) at 10 years (three and six patients, respectively, with paravalvular leak or mitral regurgitation excluded). PI correlated with preoperative (r=0.51, P<0.001), 1.5-year (r=0.46, P<0.01), and 10-year LVMi (r=0.41, P<0.01). Also preoperative left ventricular ejection fraction correlated with the three LVMi measurements. Patients with systemic hypertension had higher LVMi at 1.5 years (193+/-42, n=6 vs 144+/-42, n=33, P<0.05) and 10 years (175+/-39, n=12 vs 124+/-31g/m(2), n=29, P<0.001). Patients with low, intermediary or high PI, excluding those with hypertension, had 1.5-year LVMi of 110+/-35 (n=8), 134+/-43 (n=9) and 164+/-33g/m(2)(n=16; P<0.01), respectively, and 10-year LVMi of 116+/-25 (n=17), 126+/-27 (n=6), and 146+/-41g/m(2)(n=6; P<0.05), respectively. There was no relation between LVMi at 1.5 or 10 years and peak or mean Doppler gradient, prosthetic valve size, or valve size index. CONCLUSIONS: Left ventricular hypertrophy regression for patients who survived up to 10 years after AVR for AS is dependent on the preoperative risk profile indicating that irreversible myocardial disease is the underlying factor. Systemic hypertension is an important factor in its own right.     

Coronary reserve in patients with aortic valve disease before and after successful aortic valve replacement

In patients with aortic valve disease and normal coronary angiograms coronary reserve was determined by the coronary sinus thermodilution technique. Three groups of patients were studied: 37 preoperative patients; 18 different patients 12-52 months after aortic valve replacement and seven control subjects with no cardiac disease. Coronary flow ratio (dipyridamole/rest) was diminished in preoperative compared with postoperative patients (1.66 +/- 0.44 vs 2.22 +/- 0.85; P less than 0.05) as well as with controls (2.80 +/- 0.84; P less than 0.01), and corresponding coronary resistance ratio (dipyridamole/rest) was higher in preoperative patients than in both other groups (0.61 +/- 0.17 vs 0.48 +/- 0.14; P less than 0.05 vs 0.37 +/- 0.10; P less than 0.01). Differences in the flow ratio, but not in the resistance ratio, were significant (P less than 0.05) in patients after aortic valve replacement compared with controls. Total coronary sinus blood flow at rest was elevated in preoperative compared with both postoperative patients and controls (252 +/- 99 vs 169 +/- 63; P less than 0.01; vs 170 +/- 35 ml.min-1, P less than 0.05), whereas flows after maximal vasodilation did not differ among the three groups (416 +/- 184 vs 361 +/- 150 vs 488 +/- 235 ml.min-1). Postoperative patients showed a distinct, though not total regression of left ventricular angiographic muscle mass index and wall thickness. Nine of the 18 postoperative patients showed a normal coronary flow reserve and nine showed subnormal response. These two subgroups did not differ with respect to preoperative macroscopic and microscopic measures of hypertrophy. Thus in aortic valve disease, the reduced coronary vasodilator capacity is mainly due to an elevated coronary flow at rest, while the maximal coronary blood flow achieved is identical to that of postoperative patients and controls. With regression of left ventricular hypertrophy, flow at rest decreases and this leads to a distinct improvement of coronary flow reserve.     

Stroke-work loss underestimates hemodynamic significance of aortic stenosis in patients with hypertension

BACKGROUND: Stroke-work loss (SWL) represents the amount of energy the left ventricle dissipates as heat because of outflow obstruction. Recent studies suggest that SWL > 25% was the most clinically efficient Doppler measure for predicting hemodynamic significance, symptomatic status, and outcome in patients with aortic stenosis (AS). However, SWL may be affected by systolic blood pressure (SBP). OBJECTIVE: To determine if SWL reliably predicts hemodynamic significance of AS in patients with hypertension. METHODS: We studied 42 consecutive patients with hemodynamically significant AS requiring aortic valve replacement (AVR). Data on demographics, preoperative hemodynamics, and echocardiographic parameters were obtained. SWL was measured using the formula SWL = 100 x mean PG/ (mean PG + SBP), where PG is transaortic pressure gradient. Patients were considered hypertensive if their BP > 140/90 mmHg or if they are on antihypertensive medications. RESULTS: There were 27 males (64%) and mean age was 68 +/- 11 years. Twenty-four patients (57%) were hypertensive. Mean SBP was 134 +/- 24 mmHg, mean transaortic PG 47 +/- 20 mmHg, effective valve orifice area (EOA) by Doppler estimation 0.74 +/- 0.23 cm(2), and SWL 26 +/- 9%. Patients with hypertension had smaller SWL than normotensives (table I). SWL was >25% in 20 (49%) patients, and fewer patients with hypertension have SWL >25% (33% vs 71%, P = 0.019). Of note, patients with SWL < or =25% had significantly higher SBP (145 +/- 21 mmHg vs 122 +/- 22 mmHg, P = 0.02). CONCLUSION: SWL underestimates the hemodynamic significance of aortic stenosis in the majority of patients with hypertension.     

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.     

Determinants of long-term survival after isolated aortic valve replacement: a 10- to 17-year follow-up

During a 9-year period from January 1965 through December 1973, we performed isolated aortic valve replacement (AVR) for aortic stenosis (AS) or aortic regurgitation (AR) in 165 patients. All operations were done during total cardiac arrest using chemical cardioplegia according to the method of Bretschneider. The prostheses used were predominantly Starr-Edwards caged ball valves. One hundred thirty-nine patients were alive 30 days after operation. The 5-, 10-, and 15-year cumulative survival rates (+/- SE) were 78 +/- 4%, 62 +/- 4%, and 29 +/- 9%, respectively. In comparison to a sex- and age-matched control population, our patients had an excess mortality in the first postoperative year and again after the twelfth year. Patients who underwent AVR in 1972 and 1973 had better results than those who had operations in 1965 through 1971 (p < 0.05); the 1972-1973 patients had 5- and 10-year survival rates of 81 +/- 5% and 72 +/- 5%, respectively. The 1-year survival rate was 91% for patients with AS and 71% for those with AR (p < 0.05). In AS patients, long-term survival was adversely affected by a history of left ventricular failure, inclusion in NYHA functional class IV, cardiothoracic index of >/= 0.56, cardiac index of < 3.0 L/min/m(2), age > 55 years, previous myocardial infarction, systemic pulse pressure of /= 15 mm Hg, and mean pulmonary artery pressure of >/= 24 mm Hg. In AR patients, an adverse prognosis was associated with left ventricular failure, syncope, age >/= 60 years, and NYHA class IV status. These results indicate that, in both AS and AR patients, operation should be performed early, before severely limiting symptoms and signs arise.     

Valve structure and survival in octogenarians having aortic valve replacement for aortic stenosis (+/- aortic regurgitation) with versus without coronary artery bypass grafting at a single US medical center (1993 to 2005)

The purpose of this study was to determine the effect of simultaneous coronary artery bypass grafting (CABG) and valve structure on both early and late survival in octogenarians having aortic valve replacement (AVR) for aortic stenosis (AS) (with or without aortic regurgitation). Although a number of reports are available in octogenarians having AVR for AS, none have described aortic valve structure. Most have limited numbers of patients and few have described late results. We analyzed survival and valve structure in 196 octogenarians having AVR for AS from 1993 to 2005 at Baylor University Medical Center, including 118 (60%) with and 78 (40%) without simultaneous CABG. Sixty-day mortality, which was identical to 30-day mortality, was similar (10% and 11%) in the groups with and without simultaneous CABG. Unadjusted analysis of late survival (up to 13 year follow-up) was not affected by gender (male vs female), aortic valve structure (bicuspid vs tricuspid) or preoperative severity of the AS (transvalvular peak pressure gradient > 50 vs < or =50 mm Hg), or by performance of CABG. Of the 196 patients, 54 (28%) had a congenitally bicuspid aortic valve, and 142 (72%) had a tricuspid aortic valve. In conclusion, gender, valve structure, preoperative severity of the AS, or performance of simultaneous CABG did not effect survival in octogenarians having AVR for AS.     

Recovery of Long‐Axis Left Ventricular Function after Aortic Valve Replacement in Patients with Severe Aortic Stenosis

Background: Patients with aortic stenosis (AS) should undergo aortic valve replacement (AVR) before irreversible LV dysfunction has developed. Assessment of long‐axis left ventricular (LV) function may assist in proper timing of AVR. Objectives: To assess serial changes in long‐axis LV function before and after AVR in patients with severe AS and preserved LV ejection fraction. Methods: The study comprised 27 consecutive patients (mean age 64.9 ± 11.7 years, 15 males) with symptomatic severe AS, scheduled for AVR. Seventeen subjects without known cardiac disease, matched for age, gender, LV ejection fraction and cardiovascular risk factors, served as a control group. Long‐axis LV function assessment was done with tissue Doppler imaging at 3 weeks, 6 months, and 12 months after AVR. Results: Mean aortic valve area in the AS group was 0.70 ± 0.24 cm². Pre‐AVR peak systolic mitral annular velocities were significantly lower compared to controls (6.7 ± 1.5 vs. 8.9 ± 2.0 cm/s, P < 0.05). Post‐AVR peak systolic mitral annular velocities improved to 9.1 ± 2.9 at 3 weeks, 8.6 ± 2.7 at 6 months, and 8.1 ± 1.7 cm/s at 12 months (P < 0.05). Improvements were seen over the whole range of pre‐AVR peak systolic mitral annular velocities. Patients with improved Sm after AVR (defined as ≥10% compared to baseline values) did not differ in baseline characteristics as compared to those who did not improve. Conclusions: In patients with severe AS and preserved LV ejection fraction, abnormal systolic mitral annular velocities improve after AVR, independent of the pre‐AVR value. (Echocardiography 2010;27:1177‐1181)     

Predictable changes in left ventricular mass and function during ten years after valve replacement for aortic stenosis

BACKGROUND AND AIM OF THE STUDY: Left ventricular (LV) hypertrophy is the underlying basis for longevity after aortic valve replacement (AVR) for aortic stenosis (AS). However, a detailed account of changes in LV mass and function in the long term after AVR and identification of the determinants of such changes have not yet been presented. METHODS: Ninety-one unselected consecutive adult patients with AS underwent AVR and were followed up to 10 years, at which time 41 survivors without new mitral disease underwent repeat measurement of LV mass index (LVMi), ejection fraction (LVEF), fast filling fraction (LVFFF), and end-diastolic volume index (LVEDVi). A subgroup comprising 49 patients was also assessed at eight days, three months, and 1.5 years postoperatively. All measurements were analyzed in a longitudinal regression model for repeated measures. RESULTS: LVMi fell from 202 +/- 58 g/m2 (n = 91) via 150 +/- 45 g/m2 (n = 39) at 1.5 years to 139 +/- 40 g/m2 (n = 41) at 10 years in all patients, and to 124 +/- 31 g/m2 (n = 29) in non-hypertensive patients. The LVMi falls were paralleled by improvements in LVEF and LVEDVi. LVFFF was not correlated to LVMi before the 10-year study. The longitudinal model indicated progressive reduction of LVMi to 1.5 years, but no change thereafter. The predictor variables were preoperative LVMi and end-systolic dimension index (high values of both related to high postoperative LVMi), hypertension, and male gender. The model for LVEF indicated a rapid increase to three months, followed by a slight decrease to 1.5 years and further to 10 years, predicted by preoperative LVEF and LVFFF. LVFFF fell sharply by three months, had recovered somewhat at 1.5 years and fully at 10 years, positively related to preoperative LVFFF and inversely to end-systolic chamber radius:wall thickness ration and small-sized prosthetic valves. LVEDVi converged from extreme values over time predicted by preoperative LVEF, but rose with hypertension and coronary artery disease. Hemodynamic function of the prosthetic aortic valve at any of the measurement times had no impact. CONCLUSION: Changes in LV mass and function up to 10 years after AVR for AS were highly predictable. Poorer outcomes were related to preoperative excessive hypertrophy and indices of underlying irreversible myocardial disease and further compromised by hypertension and, to a lesser extent, coronary artery disease. The hemodynamic function of the aortic prosthetic valve did not seem to play a role.     

Relation of N-terminal pro B-type natriuretic peptide to progression of aortic valve disease.

AIMS: Recently an elevation of B-type natriuretic peptide (BNP) and its N-terminal fragment (NT-proBNP) in patients with aortic stenosis (AS) and aortic regurgitation (AR) has been described. The objective of this study was to evaluate the relation of NT-proBNP values to the progression of aortic valve disease. METHODS AND RESULTS: One hundred and sixty-eight patients were included. NT-proBNP was elevated in patients with AS (n=109) and AR (n=37) linked to disease severity. Values for NT-proBNP, pressure gradient, and left ventricular mass were identical in patients (n=22) after previous valve replacement and in those patients with mild AS. NT-proBNP levels decreased in 86 patients after valve replacement (2292+/-353 vs. 785+/-101 pg/ml; P<0.01) but increased in 82 patients who were treated conservatively (616+/-120 vs. 1155+/-432 pg/mL; P=0.029), related to the progression of disease. CONCLUSION: NT-proBNP is elevated in patients with aortic valve disease linked to disease severity and decreases after successful surgical therapy but increases in conservatively treated patients. These data underline the consistent relation of NT-proBNP to severity of aortic valve disease. Therefore, NT-proBNP should be considered as a biomarker for the monitoring of disease during follow-up, but further studies are warranted.     

Cells of primarily extra-valvular origin in degenerative aortic valves and bioprostheses.

AIMS: We assessed aortic valves from patients with non-rheumatic aortic valve stenosis (AS) and with degenerative aortic valve bioprostheses (BP) for the presence of progenitor cell and leukocyte subtype-specific markers. METHODS AND RESULTS: Diseased valve probes from a total of 87 patients (60 AS and 27 BP) were studied. We assessed presence and localization of endothelial progenitor cells (EPCs: CD34, CD133), dendritic cells (DCs: S100), T-lymphocytes (CD3), and macrophages (CD68) by immunohistochemical and morphometric analyses. In the majority of valves, we detected cell-bound signals of CD34 (48% of AS, 74% of BP, respectively), CD133 (58%/81%), S100 (58%/93%), CD3 (62%/81%), and CD68 (78%/93%). Labelled cells were predominantly localized within the valvular fibrosa. As key results, frequency of EPCs, DCs, macrophages, and lymphocytes was found significantly higher in BP when compared with AS (CD34: 19.2+/-23.2 vs. 5.7+/-13.0%; CD133: 13.7+/-12.4 vs. 5.5+/-8.3%; S100: 15.2+/-12.2 vs. 5.7+/-8.9%; CD3: 3.3+/-2.7 vs. 1.1+/-1.4%; CD68: 35.3+/-26.6 vs. 3.4+/-4.1%; each P相似文献   

Angiotensin-converting enzyme polymorphisms and their potential impact on left ventricular myocardial geometry after aortic valve surgery

BACKGROUND AND AIM OF THE STUDY: Genetic variants of the angiotensin-converting enzyme (ACE) cascade may influence left ventricular myocardial mass (LVMM) regression after aortic valve surgery. Postoperative long-term changes in LV indices were investigated in patients with asymptomatic aortic regurgitation (AR) and symptomatic aortic stenosis (AS) and related to alleles of ACE polymorphisms. METHODS: A total of 96 patients was included in the study, 21 with class IIa AR (22%) and 75 with class I AS (78%) recommendations for surgery. Patients were evaluated for demographic risk factors and underwent a thorough clinical examination including 3-D cardiac imaging by ultrafast-computed tomography. Genomic DNA was isolated for genotyping. RESULTS: AR patients were younger (55.8 +/- 8.9 versus 64 +/- 9.1 years, p = 0.0014), had a larger body surface area (1.92 +/- 0.21 versus 1.82 +/- 0.19 m2, p = 0.039), and were more likely to be asymptomatic (myocardial infarction, p = 0.04; syncope, p = 0.0099; thromboembolism, p = 0.03; NYHA class IV, p = 0.04). Postoperatively, the reduction in absolute LVMM (from 297.1 +/- 52.6 to 190.1 +/- 57.1 g versus 214.4 +/- 55.7 to 143.8 +/- 40.0 g; pT = 0.0000001) and indexed LVMM (from 156.0 +/- 31.7 to 99.3 +/- 28.4 g/m2 versus 118.7 +/- 28.3 to 79.3 +/- 20.6 g/m; pT = 0.0000001) over time was more significant in AR patients, but never reached normal values. Enforced ACE inhibitor medication resulted in significantly higher postoperative indexed LVMM differences in homozygote DD patients compared to AR patients with II/ID alleles of ACE 16 ins/del polymorphism. CONCLUSION: AR patients showed a statistically significant decrease in absolute/indexed LVMM during follow up, but never achieved LV mass recovery compared to standard values or to values in patients undergoing aortic valve replacement for AS. The benefits of ACE inhibitors were observed among AR patients with homozygote DD alleles of ACE 16 ins/del polymorphism.     

Usefulness of preoperative stroke volume as strong predictor of left ventricular remodeling and outcomes after aortic valve replacement in patients with severe pure aortic regurgitation

In most patients with aortic regurgitation (AR), aortic valve replacement (AVR) results in favorable left ventricular (LV) remodeling and normalization of the LV ejection fraction (EF). However, some patients with severe AR will not have favorable remodeling and their LVEF will not normalize. The goal of the present study was to determine whether remodeling and clinical outcomes after AVR could be predicted from simple preoperative echocardiographic analysis. A total of 56 consecutive patients with chronic severe pure AR who underwent AVR had preoperative (5 ± 2 days), early postoperative (5 ± 2 days), and late postoperative (328 ± 88 days) echocardiographic data retrospectively analyzed. The LV diameter, The LVEF and stroke volume (SV) were measured. The reduction in LV end-diastolic dimension decreased by 14% (from 65 ± 6 mm to 56 ± 8 mm, p <0.001) early after AVR, with an additional reduction of only 6% late after AVR. More than 2/3 of the overall reduction in end-diastolic dimension was observed the week after AVR. Forty-six patients (82%) had positive early LV remodeling, defined as a 10% reduction in the LV end-diastolic diameter 1 week after AVR. All patients with early LV remodeling had a preoperative SV of ≥97 ml, which was the best predictor of late postoperative LVEF of ≥45% (sensitivity 98% and specificity 100%). Patients with a preoperative SV of ≥97 ml had a markedly greater event-free survival rate (92% vs 13%, p <0.001) at 3 years. In conclusion, in patients undergoing AVR for chronic severe pure AR, preoperative SV is the best predictor of LV remodeling and outcomes.     

Prognostic Significance of LGE by CMR in Aortic Stenosis Patients Undergoing Valve Replacement

Background

Prior studies have shown that late gadolinium enhancement (LGE) by cardiac magnetic resonance (CMR) can detect focal fibrosis in aortic stenosis (AS), suggesting that it might predict higher mortality risk.

Objectives

This study was conducted to evaluate whether LGE-CMR can predict post-operative survival in patients with severe AS undergoing aortic valve replacement (AVR).

Methods

We prospectively evaluated survival (all-cause and cardiovascular disease related) according to LGE-CMR status in 154 consecutive AS patients (96 men; mean age: 74 ± 6 years) without a history of myocardial infarction undergoing surgical AVR and in 40 AS patients undergoing transcatheter aortic valve replacement (TAVR).

Results

LGE was present in 29% of patients undergoing surgical AVR and in 50% undergoing TAVR. During a median follow-up of 2.9 years, 21 patients undergoing surgical AVR and 20 undergoing TAVR died. In surgical AVR, the presence of LGE predicted higher post-operative mortality (odds ratio: 10.9; 95% confidence interval [CI]: 1.2 to 100.0; p = 0.02) and worse all-cause survival (73% vs. 88%; p = 0.02 by log-rank test) and cardiovascular disease related survival (85% vs. 95%; p = 0.03 by log-rank test) on 5-year Kaplan-Meier estimates of survival after surgical AVR. Multivariate Cox analysis identified the presence of LGE (hazard ratio: 2.8; 95% CI: 1.3 to 6.9; p = 0.025) and New York Heart Association functional class III/IV (hazard ratio: 3.2; 95% CI: 1.1 to 8.1; p < 0.01) as the sole independent predictors of all-cause mortality after surgical AVR. The presence of LGE also predicted higher all-cause mortality (p = 0.05) and cardiovascular disease related mortality (p = 0.03) in the subgroup of patients without angiographic coronary artery disease (n = 110) and higher cardiovascular disease related mortality in 25 patients undergoing transfemoral TAVR.

Conclusions

The presence of LGE indicating focal fibrosis or unrecognized infarct by CMR is an independent predictor of mortality in patients with AS undergoing AVR and could provide additional information in the pre-operative evaluation of risk in these patients.     

Left ventricular remodeling early after aortic valve replacement: differential effects on diastolic function in aortic valve stenosis and aortic regurgitation

OBJECTIVES: The aim of this study was to evaluate the effect of aortic valve replacement (AVR) on left ventricular (LV) function and LV remodeling, comparing patients with aortic valve stenosis to patients with aortic regurgitation. BACKGROUND: Aortic valve disease is associated with eccentric or concentric LV hypertrophy and changes in LV function. The relationship between LV geometry and LV function and the effect of LV remodeling after AVR on diastolic filling, in patients with aortic valve stenosis compared with aortic regurgitation, are largely unknown.Nineteen patients with aortic valve disease (12 aortic valve stenosis, 7 aortic regurgitation) were studied using magnetic resonance imaging to assess LV geometry and LV function before and 9 +/- 3 months after AVR. Ten age-matched healthy males served as control subjects. RESULTS: Before AVR, the ratio between left ventricular mass index (LVMI) and left ventricular end-diastolic volume index (LVEDVI) was only increased in patients with aortic valve stenosis (1.37 +/- 0.16 g/ml) compared with control subjects (0.93 +/- 0.08 g/ml, p < 0.05). After AVR, LVMI/LVEDVI decreased significantly in aortic valve stenosis (to 1.15 +/- 0.14 g/ml, p < 0.0001), but increased significantly in aortic regurgitation (1.02 +/- 0.20 g/ml to 1.44 +/- 0.27 g/ml, p < 0.0001). Before AVR, diastolic filling was impaired in both aortic valve stenosis and aortic regurgitation. Early after AVR, diastolic filling improved in patients with aortic valve stenosis, whereas patients with aortic regurgitation showed a deterioration in diastolic filling. CONCLUSIONS: Early after AVR, patients with aortic valve stenosis show a decrease in both LVMI and LVMI/LVEDVI and an improvement in diastolic filling, whereas in patients with aortic regurgitation, LVMI decreases less rapidly than LVEDVI, causing concentric remodeling of the LV, most likely explaining the observed deterioration of diastolic filling in these patients.     

Effects of valve replacement on left ventricular function in patients with aortic regurgitation and severe ventricular disease

BACKGROUND AND AIM OF THE STUDY: Longstanding aortic regurgitation (AR) can result in left ventricular (LV) dysfunction that may reverse after aortic valve replacement (AVR). Stentless valves may result in a more rapid recovery in function due to a more physiological flow and lower outflow resistance. METHODS: The effect of AVR on LV function was studied in 47 patients who received either a stentless (n = 33) or stented (n = 14) valve for isolated AR. All patients had evidence of pre-existing LV dysfunction (end-systolic dimension (ESD) >50 mm). Patients were studied using transthoracic echocardiography at baseline, postoperatively, and at 2.5-year follow up. RESULTS: Preoperatively, there were no differences in LV dimensions. The end-diastolic dimension fell from 75 +/- 10 mm to 61 +/- 10 mm postoperatively and to 52 +/- 10 mm at follow up in the stentless group (p <0.001), and ESD fell from 54 +/- 10 mm to 36 +/- 8 mm at follow up (p <0.001). There were no significant early changes in patients who received stented valves, though LV dimensions fell at follow up. Fractional shortening (FS) increased from 25 +/- 8% in the postoperative period to 31 +/- 7% in the stentless group (p <0.001), but there was no change in the stented group (20 +/- 7% versus 23 +/- 8%). In the stentless group, LV mass fell from 366 +/- 104 g to 276 +/- 68 g postoperatively and to 219 +/- 79 g at follow up (p <0.001); there was no postoperative change in the stented group, though a late reduction occurred, from 349 +/- 51 g preoperatively to 265 +/- 61 g at follow up (p = 0.06). CONCLUSION: For patients with AR and LV dysfunction, AVR with a stentless prosthesis offers early reductions in LV dimensions, improved LV function, and regression of LV mass. In patients who received a stented valve, these improvements were delayed and less complete. Hence, for some patients with AR and LV dysfunction, a stentless prosthesis may be preferable.     

Doppler echocardiographic assessment of hemodynamic progression of valvular aortic stenosis over time: comparison between aortic valve resistance and valve area.

BACKGROUND: Doppler-derived aortic valve resistance (AVR), i.e. the ratio between pressure gradient and flow rate, has been proposed as an alternative parameter to valve area (AVA) for assessing the hemodynamic severity of aortic stenosis (AS). There are no data on the evaluation of hemodynamic progression of AS using AVR. METHODS: Forty-five adult patients (24 women and 21 men, mean age 72 +/- 10 years) with AS were followed up for 18 months (range 6 to 45 months) with serial Doppler-derived AVR (Isaaz, JACC 1991; 18: 1661) and AVA (continuity equation). Rates of change of AVR and AVA over time were indexed for year of follow-up; furthermore, variations of these parameters during follow-up were expressed as percent change from baseline. RESULTS: During the follow-up period, AVA decreased from 0.74 +/- 0.28 to 0.6 +/- 0.17 cm2 (p < 0.05), with a rate of change of -0.1 +/- 0.13 cm2/year; AVR increased from 349 +/- 187 to 462 +/- 180 dyne/s/cm-5 (p < 0.05), with a rate of change of 79 +/- 69 dyne/s/cm-5/year. Variations observed in AVR, expressed as percent change from baseline, were larger than those observed in AVA (51 +/- 62% versus -16.5 +/- 15%). AVR percent change from baseline significantly correlated with AVA percent change from baseline (r = 0.83, p < 0.05). During follow-up, 6 patients showed no change in AVA: AVR was unchanged in 3 and increased in the remaining 3 patients (6, 11 and 58%, respectively), indicating a progression of AS severity that could not be appreciated from AVA alone. CONCLUSIONS: Serial changes in AVR, as assessed by Doppler echocardiography, significantly correlate with changes in AVA. Thus, the noninvasive assessment of AVR may be utilized in the evaluation of hemodynamic progression of AS and, in conjunction with AVA, may also provide complementary information for the management of these patients.     

Effects of valve replacement for aortic stenosis on mitral regurgitation

We aimed to prospectively and quantitatively assess the effects of aortic valve replacement (AVR) for aortic stenosis (AS) on mitral regurgitation (MR) and to examine the determinants of the changes in MR. Fifty-two patients with AS scheduled for AVR were included if holosystolic MR not being considered for replacement or repair was detected. MR was quantified using the proximal isovelocity surface area method before and 8 +/- 4 days after surgery. Mitral valvular deformation parameters did not change significantly, but the mitral effective regurgitant orifice (ERO) and regurgitant volume decreased from 11 +/- 6 mm(2) to 8 +/- 6 mm(2) and from 20 +/- 10 ml to 11 +/- 9 ml, respectively (both p <0.0001). Using multiple linear regression analysis, preoperative severity of MR, mitral leaflet coaptation height, and end-diastolic volume decrease were independently associated with postoperative reduction in MR, whereas changes in mitral valve morphology after surgery were not. MR etiology did not predict the reduction in MR. In conclusion, the decrease in MR observed in most patients after AVR is associated with the magnitude of acute left ventricular reverse remodeling. As the reduction in left ventricular systolic pressure contributes to the decrease in regurgitant volume, the preoperative quantitative assessment of MR should best be performed by measurement of the ERO.     

Is ventricular repolarization heterogeneity a cause of serious ventricular tachyarrhythmias in aortic valve stenosis?

BACKGROUND: It is well known that there is a close relation between sudden cardiac death and serious ventricular tachyarrhythmias in patients with aortic valve stenosis (AS). QT dispersion (QTd) reflects the ventricular repolarization heterogeneity and has been proposed as an indicator for ventricular arrhythmias. HYPOTHESIS: This study investigated the QTd and its relevance to the clinical and echocardiographic variables. METHODS: In all, 51 patients (33 men, 18 women, mean age 56 +/- 12) with isolated AS and 51 age- and gender-matched healthy controls comprised the study group. Left ventricular mass index (LVMI) was calculated by the Devereux formula, and we used continuous-wave Doppler (n = 15) and cardiac catheterization (n = 36) for the determination of the maximum aortic valve pressure gradient (PG). RESULTS: Corrected QTd (QTcd) (89 +/- 39 vs. 49 +/- 15 ms, p < 0.001) and LVMI (176 +/- 69 g/m2 vs. 101 +/- 28 g/m2, p < 0.001) in patients with AS were significantly different from those in the control group. The group of 21 patients had a significantly greater number of 24-h mean ventricular premature beats (VPB) and mean number of couplet VT episodes than did the control group (p < 0.05). QTcd also correlated significantly well with LVMI (r = 0.58, p < 0.001), PG (r = 0.41, p = 0.003), and number of 24-h VPB (r = 0.56, p = 0.008). With respect to symptoms (e.g., angina, syncope, and dyspnea) patients without symptoms (n = 19) displayed less QTcd (71 +/- 31 vs. 100 +/- 39 ms, p = 0.007) and less LVMI (144 +/- 80 g/m2 vs. 195 +/- 57 g/m2, p = 0.01) than patients with symptoms. Statistical analysis was similar for all variables with uncorrected QTd values. CONCLUSION: We found that ventricular repolarization heterogeneity was greater in patients with AS than in controls. Our findings also showed that QTd in the patient group correlates well with LVMI, severity of AS, and PG. The present results suggest that serious ventricular arrhythmias in patients with AS may be due to spatial ventricular repolarization abnormality.