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

Is the threshold for postoperative prosthesis-patient mismatch the same for all prostheses?

PURPOSE

The effective orifice area index (EOAI) is used to define the prosthesis-patient mismatch (PPM) after aortic valve replacement (AVR). However, few studies have so far evaluated whether the cutoff value for PPM varies across prostheses. This study assessed the hemodynamics in patients given a mechanical valve and then re-evaluated the validity of the commonly accepted threshold.

METHODS

The subjects included 329 patients that underwent AVR with a St. Jude Medical Regent valve. The transvalvular pressure gradient and EOAI were determined echocardiographically, and the commonly accepted threshold was analyzed in relation to survival.

RESULTS

The mechanical valves very often yielded a postoperative transvalvular pressure gradient >10 mmHg, and thus, clinically significant residual pressure, regardless of the EOAI. The slope of the curve describing the relationship between the transvalvular pressure gradient and EOAI was gentler than that reported for bioprosthetic valves, for which the pressure gradient rises sharply at EOAI <0.85 cm(2)/m(2). The commonly defined PPM did not affect the long-term survival or regression of the left ventricular mass index.

CONCLUSIONS

The relationship between the transvalvular pressure gradient and the EOAI in patients given a mechanical prosthesis differed from the reference standard. These data suggest the need to reconsider the appropriate cutoff value for PPM in relation to different prostheses.

Comparing aortic root replacements: porcine bioroots versus pericardial versus mechanical composite roots: hemodynamic and ventricular remodeling at greater than one-year follow-up

BACKGROUND

Stentless porcine bioroots and pericardial composite roots were developed as prostheses that avoid the anticoagulation necessary for mechanical composite roots. Data on the hemodynamics of all root replacements are lacking and questions remain regarding comparative performance.

METHODS

This study evaluated patients receiving a stentless porcine bioroot, a pericardial, or a mechanical composite root at a single institution from January 2000 to December 2008. All patients underwent preoperative, postoperative and greater than 1-year echocardiograms. All root replacements were performed for aortic insufficiency or aneurysm. Median follow-up was 3.3 years (1 to 8 years).

RESULTS

There were no significant differences in preoperative left ventricular ejection fraction, aortic valve peak gradient, mean gradient, left ventricular end diastolic diameter, and left ventricular end systolic diameter. Postoperative peak and mean gradients in mechanical composite roots were significantly higher than stentless porcine bioroots. At greater than 1 year, stentless porcine bioroots had significantly lower peak and mean gradients than both mechanical composite roots and pericardial composite roots. The end diastolic diameter was also significantly smaller in stentless porcine bioroots at greater than 1 year than mechanical composite roots.

CONCLUSIONS

All prostheses resulted in favorable hemodynamic and ventricular remodeling. Stentless porcine bioroots had the lowest gradients at greater than 1 year of all root replacements, with significantly better ventricular remodeling when compared with mechanical composite roots. Pericardial roots also had favorable hemodynamics and ventricular remodeling, suggesting that they are a viable alternative.

Primary echocardiographic results of the Carpentier-Edwards Perimount Magna

PURPOSE

The aim of this study was to investigate the primary echocardiographic results of aortic valve replacement using 21- and 19-mm Carpentier-Edwards Perimount Magna bioprosthesis aortic xenografts in patients with small aortic annulus.

METHODS

Twenty patients (mean body surface area 1.63 ± 0.16 m(2)) underwent aortic valve replacement between June 2008 and December 2009. Eight and 12 patients received 21- and 19-mm Magna bioprostheses, respectively. After 12 months, hemodynamic data were obtained by echocardiography to estimate the prosthesis-patient mismatch.

RESULTS

At follow-up, significant decreases in peak and mean left ventricular aortic pressure gradients were observed in the 12 patients with aortic stenosis (P < 0.05). Regression of the left ventricular mass was observed in all the patients (P < 0.05). The mean measured effective orifice area (EOA) and EOA index (EOAI) were 1.61 ± 0.28 cm(2) and 0.99 ± 0.16 cm(2)/m(2), respectively. Prosthesis-patient mismatch (EOAI ≤0.85) was documented in three patients.

CONCLUSION

The primary echocardiographic findings suggested that the hemodynamic performance of the 19- and 21-mm Carpentier-Edwards Perimount Magna bioprostheses was satisfactory in the patients with a small aortic annulus.

Impact of patient-prosthesis mismatch on 30-day outcomes in young and middle-aged patients undergoing aortic valve replacement

Background

The impact of patient-prosthesis mismatch (PPM) on early outcomes in young and middle-aged patients undergoing conventional aortic valve replacement for severe aortic stenosis remains unknown. Our objective was to evaluate the incidence of some degree of PPM and its influence on early mortality and morbidity.

Methods

We analyzed our single center experience in all patients <70 years undergoing first-time isolated aortic valve replacement for severe stenosis in our center from September 2007 to September 2011. PPM was defined as an indexed effective orifice area ≤ 0,85 cm²/m². The influence of PPM on early mortality and postoperative complications was studied using propensity score analysis. Follow up at 30 postoperative days was 100% complete.

Results

Of 199 patients studied, 61 (30,7%) had some degree of PPM. PPM was associated with an increased postoperative mortality (OR = 8,71; 95% CI = 1,67–45,29; p = 0,04) and major postoperative complications (OR = 2,96; CI = 1,03–8,55; p = 0,044). However, no association between PPM and prolonged hospital or ICU stay was demonstrated.

Conclusions

Moderate PPM is a common finding in young and middle-aged patients undergoing surgery for aortic valve replacement due to severe stenosis. In addition, its influence on early outcomes may be relevant.

Doppler haemodynamics and effective orifice areas of Edwards SAPIEN and CoreValve transcatheter aortic valves

AIMS

Transcatheter aortic valve implantation (TAVI) is a new therapy for severe aortic stenosis in high-risk patients. So far, no reference values for the echocardiographic assessment of this new class of heart valves have been established. The aim of our study was to determine Doppler haemodynamics and the effective orifice area (EOA).

METHODS AND RESULTS

We retrospectively analysed the earliest transthoracic echocardiographic examinations of 146 stable patients after successful TAVI (median 8±20 days). Doppler examinations were analysed for peak instantaneous velocity, peak, and the mean systolic gradient. EOA was determined using the continuity equation. Patients with severe paravalvular aortic or mitral valve regurgitation were excluded. The overall peak instantaneous velocity (n=146) was 2.0±0.4 m/s with a peak systolic gradient of 17.1±7.4 mmHg and a mean gradient of 9.3±4.5 mmHg. The mean EOA was 1.82±0.43 cm2 with an indexed EOA of 1.0±0.27 cm2/m2. In general, all prostheses showed similar values-with the exception of the Edwards Sapien 23 mm which was associated with higher velocities and peak pressure gradients.

CONCLUSION

Our study establishes the normal range for Doppler haemodynamics of four transcatheter aortic valve prostheses. Compared with previously published data of surgically implanted bioprostheses percutaneous valves tend to have similar EOA values but lower mean peak velocities and pressure gradients. In comparison with physiological haemodynamics; however, this new class of heart valves is still associated with a mild obstruction.

Clinical predictors of prosthesis-patient mismatch after aortic valve replacement for aortic stenosis

OBJECTIVE

We sought to ascertain predictors of Patient Prosthesis Mismatch, an independent predictor of mortality, in patients with aortic stenosis using bioprosthetic valves.

METHOD

We analyzed 2,107 sequential surgeries. Patient Prosthesis Mismatch was calculated using the effective orifice area of the prosthesis divided by the patient's body surface area. We defined nonsignificant, moderate, and severe Patient Prosthesis Mismatch as effective orifice area indexes of .0.85 cm(2)/m, 0.85-0.66 cm(2)/m(2), and <0.65 cm(2)/m(2), respectively.

RESULTS

A total of 311 bioprosthetic patients were identified. The incidence of nonsignificant, moderate, and severe Patient Prosthesis Mismatch was 41%, 42, and 16%, respectively. Severe Patient Prosthesis Mismatch was significantly more prevalent in females (82%). In severe Patient Prosthesis Mismatch, the perfusion and the crossclamp times were considerably lower when compared with nonsignificant Patient Prosthesis Mismatch and moderate Patient Prosthesis Mismatch. Patients with severe Patient Prosthesis Mismatch had a significantly higher likelihood of spending time in the intensive care unit and a significantly longer length of stay in the hospital. Body surface area was not different in severe Patient Prosthesis Mismatch when compared with nonsignificant Patient Prosthesis Mismatch. In-hospital mortality in patients with nonsignificant, moderate, and severe Patient Prosthesis Mismatch was 2.3%, 6.1%, and 8%, respectively. Minimally invasive surgery was significantly associated with moderate Patient Prosthesis Mismatch in 49% of the patients, but not with severe Patient Prosthesis Mismatch.

CONCLUSION

Severe Patient Prosthesis Mismatch is more common in females, but not in those with minimal available body surface area. Though operative times were shorter in these patients, intensive care unit and hospital lengths of stay were longer. Surgeons and cardiologists should be cognizant of these clinical predictors and complications prior to valve surgery.

Mid-term outcomes after aortic valve replacement with the 17-mm St. Jude Medical Regent valve

BACKGROUND

When aortic valve replacement (AVR) is performed in patients with a small aortic annulus, prosthesis-patient mismatch (PPM) is of concern. We investigated the mid-term outcomes of AVR with a 17-mm mechanical prosthesis.

METHODS AND RESULTS

Seventy-eight patients with aortic stenosis underwent AVR with a 17-mm St. Jude Medical Regent prosthesis. Echocardiography was performed preoperatively, at discharge, and at follow-up (mean follow-up, 33 months). Patients were divided into 2 groups: with and without PPM at discharge. Between-group differences in postoperative variables, particularly survival, were analyzed. Overall hospital mortality was 2.6%. Actuarial 1- and 5-year survival rates were 95% and 79%, respectively. Diabetes and renal insufficiency were associated with long-term mortality. Freedom from major adverse valve-related cardiac events at 1 year and 5 years was 97.3% and 93.9%, respectively. Diabetes was shown to be an independent risk factor for major adverse valve-related cardiac events. Echocardiography 13 months after AVR showed a significant increase in mean effective orifice area index, decrease in mean left ventricular-aortic pressure gradient, and decrease in mean left ventricular mass index. PPM at discharge did not influence long-term survival or left ventricular mass regression.

CONCLUSIONS

The 17-mm Regent prosthesis provided satisfactory clinical and hemodynamic results. It is a reliable choice for patients with a small aortic annulus.

Early Doppler-echocardiography evaluation of Carpentier-Edwards Standard and Carpentier-Edwards Magna aortic prosthetic valve: comparison of hemodynamic performance

OBJECTIVES

This study was designed to describe Doppler-echocardiography values of Carpentier-Edwards Perimount Standard (CEPS) and Carpentier-Edwards Perimount Magna (CEPM) aortic prosthetic valves, evaluated by a single, experienced echo-laboratory, early in the postoperative phase.

METHODS

Three-hundred-seventy-seven consecutive patients, who had had a CEPS or a CEPM implanted in our Hospital due to aortic stenosis and/or insufficiency, underwent baseline Doppler echocardiography evaluation within 7 days after surgery. Hemodynamic performances of CEPS and CEPM were accurately described, evaluating flow-dependent (transprosthetic velocities and gradients) and flow-independent (effective orifice area, indexed effective orifice area and Doppler velocity index) Doppler-echocardiography parameters.

RESULTS

Out of the 377 patients 48.8% were men (n = 184), mean age was 74.63 ± 6.77 years, mean BSA was 1.78 ± 0.18 m2, mean ejection fraction was 57.78 ± 8%. Two-hundred and sixty two CEPS and 115 CEPM were implanted. Comparing size-by-size CEPS with CEPM, both prostheses showed a good hemodynamic profile, with fairly similar values of pressure gradients (PGmax and mean, in mmHg, = 37,18 ± 11.57 and 20.81 ± 7.44 in CEPS n°19 compared to 32,47 ± 7,76 and 17,67 ± 4.63 in CEPM n°19 and progressively lower in higher sized prostheses, having PGmax and mean 15 ± 3,16 and 9.15 ± 1,29 in CEPS n°29 compared to 15,67 ± 1,53 and 9 ± 1 in CEPM n°29) and EOAi (being 0,65 ± 0,33 cm²/m² in CEPS n°19 compared to 0,77 ± 0,29 cm²/m² in CEPM n°19 and progressively higher in higher sized prostheses, being 1,28 ± 0,59 cm²/m² in CEPS n°29 compared to 1,07 ± 0,18 cm²/m² in CEPM n°29), the latter resulting, however, basically less flow obstructive.

CONCLUSIONS

Our data confirm the good hemodynamic performance of both aortic bioprostheses and the more favourable hemodynamic profile of CEPM compared to CEPS, pointing out the need to perform routinely an accurate baseline Doppler-echocardiography evaluation early after surgery to allow an adequate interpretation of data at follow-up.

Aortic valve replacement with smaller valve size

The occurrence of prosthesis-patient mismatch after aortic valve replacement with a small valve size was evaluated in 249 patients, focusing on echocardiographic data. Aortic valve pathology included regurgitation in 174 patients and stenosis in 75. Echocardiography was performed in the early and late postoperative periods. A projected effective orifice area index < 0.85 cm(2)·m(-2) was noted in 56 patients; values ≥ 0.85 cm(2)·m(-2) were found in 128. Postoperative changes in ejection fraction, left ventricular mass regression, and peak transprosthetic gradient were similar in both groups. Small prostheses (≤ 19 mm) were used in 43 patients who had significantly higher postoperative transprosthetic gradients in both the early and late periods, compared to those with larger prostheses. Our findings show that the occurrence of prosthesis-patient mismatch after aortic valve replacement is rare. Left ventricular mass regression occurred in most patients, with acceptable transprosthetic gradients.

Clinical outcomes and hemodynamics of the 19-mm Perimount Magna bioprosthesis in an aortic position: comparison with the 19-mm Medtronic Mosaic Ultra Valve

BACKGROUND

When aortic valve replacement is performed in patients with a small aortic annulus, prosthesis-patient mismatch (PPM) is of concern because it can affect postoperative clinical outcomes. Although larger bioprosthetic valves have been well studied, the hemodynamics of 19-mm bioprostheses have been reported in only a small number of patients. The effectiveness as well as the impact of PPM on outcomes are thus still unclear.

METHODS AND RESULTS

Postoperative clinical and hemodynamic variables were compared in 67 patients with a 19-mm Carpentier Edwards Perimount Magna bioprosthesis and in 10 patients with a 19-mm Medtronic Mosaic Ultra valve. Mean follow-up time was 13 months. There was no in-hospital mortality. Echocardiography 6.5±4.0 months after surgery showed significant decreases in the mean left ventricular (LV)-aortic pressure gradient, and decreases in the mean LV mass index. Reduction in LV mass index did not differ between the valve groups, despite a higher pressure gradient in the Mosaic group. Although PPM was detected in 21 patients in the Magna group, it did not affect regression of the LV mass index during the follow-up period.

CONCLUSIONS

Use of the 19-mm Magna bioprosthesis appears to provide satisfactory clinical results. LV-aortic pressure gradient was lower in the Magna group. The present data suggest that PPM is not related to reduction in the LV mass index.

Prosthesis-patient mismatch: an update

Prosthesis-patient mismatch (PPM) is present when the effective orifice area of the inserted prosthetic valve is too small in relation to body size. Its main hemodynamic consequence is to generate higher than expected gradients through normally functioning prosthetic valves. The purpose of this review is to present an update on the present state of knowledge with regard to diagnosis, prognosis, and prevention of PPM. PPM is a frequent occurrence (20% to 70% of aortic valve replacements) that has been shown to be associated with worse hemodynamics, less regression of left ventricular hypertrophy, more cardiac events, and lower survival. Moreover, as opposed to most other risk factors, PPM can largely be prevented by using a prospective strategy at the time of operation.

Predictors of moderate-to-severe paravalvular aortic regurgitation immediately after CoreValve implantation and the impact of postdilatation

OBJECTIVE

To investigate the predictors of moderate-to-severe aortic regurgitation (AR≥2+) after CoreValve implantation and evaluate the feasibility and safety of postdilatation in reducing the degree of AR.

BACKGROUND

Although transcatheter aortic valve implantation is an alternative treatment for high surgical risk patients with severe aortic stenosis, post-implantation paravalvular AR remains a complication.

METHODS

From July 2008 to July 2010, we enrolled 79 consecutive patients with severe aortic stenosis who underwent CoreValve implantation.

RESULTS

On univariable analysis, the predictors of AR≥2+ immediately after CoreValve implantation were: larger annulus size, low implantation, prosthesis mismatch, chronic renal insufficiency, a history of heart failure, and peripheral vascular disease. On multivariable analysis, the independent predictors of AR≥2+ were: larger annulus diameter (OR 1.78, 95%CI 1.25-2.55; P = 0.002), low implantation (OR 3.67, 95%CI 1.01-13.35, P = 0.05), and peripheral vascular disease (OR 3.54, 95%CI 1.19-10.56, P = 0.02). Post-CoreValve implantation, AR ≥ 2 was seen in 40.5% (32/79). Twenty-one patients underwent postdilatation with improvement in AR grade in the majority (17/21). Of the four patients who did not respond to postdilatation, two underwent valve-in-valve implantation. In one patient, the valve was pulled more proximally by the snare technique. The remaining 10 patients were treated conservatively.

CONCLUSION

The appropriate strategy for treating patients with AR≥2+ depends on the causes and severity of AR post-TAVI. This study suggests that we should carefully select the size of CoreValve prosthesis to prevent prosthesis mismatch, especially when implanted in larger annulus sizes. For valves implanted in the appropriate position, postdilatation appears effective in reducing the degree of AR.

Pulmonary hypertension in cardiac surgery

Pulmonary hypertension is an important prognostic factor in cardiac surgery associated with increased morbidity and mortality. With the aging population and the associated increase severity of illness, the prevalence of pulmonary hypertension in cardiac surgical patients will increase. In this review, the definition of pulmonary hypertension, the mechanisms and its relationship to right ventricular dysfunction will be presented. Finally, pharmacological and non-pharmacological therapeutic and preventive approaches will be presented.

Diagnostic evaluation of left-sided prosthetic heart valve dysfunction

Prosthetic heart valve (PHV) dysfunction is a rare, but potentially life-threatening, complication. In clinical practice, PHV dysfunction poses a diagnostic dilemma. Echocardiography and fluoroscopy are the imaging techniques of choice and are routinely used in daily practice. However, these techniques sometimes fail to determine the specific cause of PHV dysfunction, which is crucial to the selection of the appropriate treatment strategy. Multidetector-row CT (MDCT) can be of additional value in diagnosing the specific cause of PHV dysfunction and provides valuable complimentary information for surgical planning in case of reoperation. Cardiac magnetic resonance imaging (CMR) has limited value in the evaluation of biological PHV dysfunction. In this Review, we discuss the use of established imaging modalities for the detection of left-sided mechanical and biological PHV dysfunction and discuss the complementary role of MDCT in this context.

Defining patient-prosthesis mismatch and its effect on survival in patients with impaired ejection fraction

BACKGROUND

How best to define patient-prosthesis mismatch (PPM) continues to be debated. Over time, the indexed effective orifice area has become the most widely used method. However, the clinical relevance of PPM remains controversial.

METHODS

The indexed geometric orifice area and indexed effective orifice area were calculated for 143 patients having undergone aortic valve replacement with a normal left ventricular function 0.45 or less. Using the indexed geometric orifice area method, PPM was defined as nonsignificant if 1.2 cm(2)/m(2) or greater and as significant if less than 1.2 cm(2)/m(2). Using the indexed effective orifice area method, PPM was considered as nonsignificant if greater than 0.85 cm(2)/m(2), as moderate if greater than 0.65 cm(2)/m(2) and less than or equal to 0.85 cm(2)/m(2), and as severe PPM if 0.65 cm(2)/m(2) or less.

RESULTS

The number of patients classified as having PPM differed according to the method used to predict its presence (PPM: Effective orifice area method = 72.7%; geometric method = 19.6%). Regardless of the method used to classify PPM there was no significant effect on mortality (adjusted hazard ratio: 2.65 at 1 year, 0.99 at 5 years, 0.92 at 9 years; p = not significant). The postoperative mean transvalvular gradient (17.1 ± 6.5 mm Hg) and left ventricular function (0.50 ± 0.145) improved significantly compared with the preoperative findings.

CONCLUSIONS

The method used to calculate PPM resulted in significant classification discordance. However, regardless of classification, the presence of PPM did not adversely affect long-term outcome.

Impact of concomitant aortic regurgitation on long-term outcome after surgical aortic valve replacement in patients with severe aortic stenosis

Background

Prognostic value of concomitant aprtic regurgitation (AR) in patients operated for severe aortic stenosis (AS) is not clarified. The aim of this study was to prospectively examine the impact of presence and severity of concomitant AR in patients operated for severe AS on long-term functional capacity, left ventricular (LV) function and mortality.

Methods

Study group consisted of 110 consecutive patients operated due to severe AS. The patients were divided into AS group (56 patients with AS without AR or with mild AR) and AS+AR group (54 patients with AS and moderate, severe or very severe AR). Follow-up included clinical examination, six minutes walk test (6MWT) and echocardiography 12 and 104 months after AVR.

Results

Patients in AS group had lower LV volume indices throughout the study than patients in AS+AR group. Patients in AS group did not have postoperative decrease in LV volume indices, whereas patients in AS+AR group experienced decrease in LV volume indices at 12 and 104 months. Unlike LV volume indices, LV mass index was significantly lower in both groups after 12 and 104 months as compared to preoperative values. Mean LVEF remained unchanged in both groups throughout the study. NYHA class was improved in both groups at 12 months, but at 104 months remained improved only in patients with AS. On the other hand, distance covered during 6MWT was longer at 104 months as compared to 12 months only in AS+AR group (p = 0,013), but patients in AS group walked longer at 12 months than patients in AS+AR group (p = 0,002). There were 30 deaths during study period, of which 13 (10 due to cardiovascular causes) in AS group and 17 (12 due to cardiovascular causes) in AS+AR group. Kaplan-Meier analysis showed that the survival probability was similar between the groups. Multivariate analysis identified diabetes mellitus (beta 1.78, p = 0.038) and LVEF < 45% (beta 1.92, p = 0.049) as the only independent predictor of long-term mortality.

Conclusion

Our data indicate that the preoperative presence and severity of concomitant AR has no influence on long-term postoperative outcome, LV function and functional capacity in patients undergoing AVR for severe AS.

Comparison between transcatheter and surgical prosthetic valve implantation in patients with severe aortic stenosis and reduced left ventricular ejection fraction

BACKGROUND

Patients with severe aortic stenosis and reduced left ventricular ejection fraction (LVEF) have a poor prognosis with conservative therapy but a high operative mortality when treated surgically. Recently, transcatheter aortic valve implantation (TAVI) has emerged as an alternative to surgical aortic valve replacement (SAVR) for patients considered at high or prohibitive operative risk. The objective of this study was to compare TAVI and SAVR with respect to postoperative recovery of LVEF in patients with severe aortic stenosis and reduced LV systolic function.

METHODS AND RESULTS

Echocardiographic data were prospectively collected before and after the procedure in 200 patients undergoing SAVR and 83 patients undergoing TAVI for severe aortic stenosis (aortic valve area ≤1 cm(2)) with reduced LV systolic function (LVEF ≤50%). TAVI patients were significantly older (81±8 versus 70±10 years; P<0.0001) and had more comorbidities compared with SAVR patients. Despite similar baseline LVEF (34±11% versus 34±10%), TAVI patients had better recovery of LVEF compared with SAVR patients (ΔLVEF, 14±15% versus 7±11%; P=0.005). At the 1-year follow-up, 58% of TAVI patients had a normalization of LVEF (>50%) as opposed to 20% in the SAVR group. On multivariable analysis, female gender (P=0.004), lower LVEF at baseline (P=0.005), absence of atrial fibrillation (P=0.01), TAVI (P=0.007), and larger increase in aortic valve area after the procedure (P=0.01) were independently associated with better recovery of LVEF.

CONCLUSION

In patients with severe aortic stenosis and depressed LV systolic function, TAVI is associated with better LVEF recovery compared with SAVR. TAVI may provide an interesting alternative to SAVR in patients with depressed LV systolic function considered at high surgical risk.

Aortic valve replacement with 17-mm St. Jude Medical Regent prosthetic valves for a small calcified aortic annulus in elderly patients

PURPOSE

The aim of this study was to investigate the outcome of aortic valve replacement (AVR) performed with a 17-mm St. Jude Medical Regent prosthetic valve (17SJMR) for an aortic annulus ≤19 mm in elderly patients aged ≥65 years.

METHODS

Six female patients (age 73.0 ± 5.1 years, body surface area 1.43 ± 0.07 m²) underwent AVR between October 2005 and February 2008.

RESULTS

Peak transaortic pressure gradient, which was 80.8 ± 31.0 mmHg preoperatively, decreased to 31.0 ± 4.2 mmHg postoperatively (P < 0.01) and to 21.7 ± 1.5 mmHg long term (P < 0.01). The left ventricular mass index, which was 112.1 ± 10.6 g/m² preoperatively, also significantly decreased to 101.4 ± 15.0 g/m² postoperatively and to 88.3 ± 14.8 g/m² long term (P < 0.01). Subjective symptoms diminished in all patients, and neither mortality nor hemorrhagic complications occurred. The postoperative mean effective orifice area index was 0.91 ± 0.04 cm²/m².

CONCLUSION

A favorable outcome was obtained by aortic valve replacement with the 17SJMR. Patients showed improved postoperative hemodynamic performance without valve-related complications.

Hemodynamics and Outcomes of Aortic Valve Replacement with a 17- or 19-mm Valve

When aortic valve replacement is performed in patients with a small aortic annulus, prosthesis-patient mismatch is of concern because it may affect postoperative clinical status. We conducted a retrospective study of outcomes in 65 patients with aortic stenosis requiring valve replacement. Fifty were given a 17-mm or 19-mm St. Jude Regent mechanical valve, and 15 were given a 19-mm Medtronic Mosaic bioprosthesis. Echocardiography was carried out preoperatively, at discharge, and at follow-up. There was 1 (2%) operative death in the Regent group and none in the Mosaic group. There was no valve-related event. Follow-up echocardiography in both groups revealed a significant increase in the mean effective orifice area index, a decrease in the mean left ventricular-aortic pressure gradient, and a decrease in the mean left ventricular mass index. Prosthesis-patient mismatch (effective orifice area index <0.85 cm2 · m−2) existed in 13 (26%) patients in the Regent group and 11 (73%) in the Mosaic group at discharge. All patients improved to New York Heart Association functional class II or better. A small-sized prosthesis may provide satisfactory clinical and hemodynamic results in patients with a small aortic annulus.

Left ventricular reverse remodeling in percutaneous and surgical aortic bioprostheses: an echocardiographic study

BACKGROUND

Surgical aortic valve replacement (SAVR) is the definitive proven therapy for patients with severe aortic stenosis who have symptoms or decreased left ventricular (LV) function. The development of transcatheter aortic valve implantation (TAVI) offers a viable and "less invasive" option for the treatment of patients with critical aortic stenosis at high risk with conventional approaches. The main objective of this study was the comparison of LV hemodynamic and structural modifications (reverse remodeling) between percutaneous and surgical approaches in the treatment of severe aortic stenosis.

METHODS

Fifty-eight patients who underwent TAVI with the CoreValve bioprosthetic valve were compared with 58 patients with similar characteristics who underwent SAVR. Doppler echocardiographic data were obtained before the intervention, at discharge, and after 6-month to 12-month follow-up.

RESULTS

Mean transprosthetic gradient at discharge was lower (P<.003) in the TAVI group (10±5 mm Hg) compared with the SAVR group (14±5 mm Hg) and was confirmed at follow-up (10±4 vs 13±4 mm Hg, respectively, P<.001). Paravalvular leaks were more frequent in the TAVI group (trivial to mild, 69%; moderate, 14%) than in the SAVR group (trivial to mild, 30%; moderate, 0%) (P<.0001). The incidence of severe prosthesis-patient mismatch (PPM) was significantly lower (P<.004) in the TAVI group (12%) compared with the SAVR group (36%). At follow-up, LV mass and LV mass indexed to height and to body surface area improved in both groups, with no significant difference. In patients with severe PPM, only the TAVI subgroup showed significant reductions in LV mass. LV ejection fraction improved at follow-up significantly only in TAVI patients compared with baseline values (from 50.2±9.6% to 54.8±7.3%, P<.0001).

CONCLUSIONS

Hemodynamic performance after TAVI was shown to be superior to that after SAVR in terms of transprosthetic gradient, LV ejection fraction, and the prevention of severe PPM, but with a higher incidence of aortic regurgitation. Furthermore, LV reverse remodeling was observed in all patients in the absence of PPM, while the same remodeling occurred only in the TAVI subgroup when severe PPM was present.

Intraoperative Hemodynamic Instability During and After Separation From Cardiopulmonary Bypass

Every year, more than 1 million patients worldwide undergo cardiac surgery. Because of the aging of the population, cardiac surgery will increasingly be offered to patients at a higher risk of complications. The consequence is a reduced physiological reserve and hence an increased risk of mortality. These issues will have a significant impact on future health care costs because the population undergoing cardiac surgery will be older and more likely to develop postoperative complications. One of the most dreaded complications in cardiac surgery is difficult separation from cardiopulmonary bypass (CPB). When separation from CPB is associated with right-ventricular failure, the mortality rate will range from 44% to 86%. Therefore, the diagnosis and the preoperative prediction of difficult separation from CPB will be crucial to improve the selection and care of patients and to prevent complications for this high-risk patient population.

Choice of prosthetic heart valve in adults an update

In the last 7 years, more data have reconfirmed that patients' comorbid conditions are very important factors determining patient outcomes. Prosthetic heart valves (PHVs) that require aortic root replacement in the absence of aortic root disease are associated with poorer outcomes. For the vast majority of patients, the choice of PHV is between a mechanical valve and a stented bioprosthesis. The choice is largely dependent upon the age of the patient at the time of PHV implantation and on which complication the patient wants to avoid: specifically, anticoagulation therapy and its complications with the mechanical valve, and structural valve deterioration with a bioprosthesis. Data on the pros and cons of the choices and exceptions to the rules are discussed, and a new algorithm is developed.

Hemodynamic results and changes in myocardial function after transcatheter aortic valve implantation

BACKGROUND

This prospective study was designed to evaluate the hemodynamic results of transcatheter aortic valve implantation (TAVI) with the CoreValve prosthesis (Medtronic, Minneapolis, Minnesota) and the effects on left ventricular function.

METHODS

From June 2008 to June 2009, consecutive patients with severe symptomatic aortic valve stenosis (aortic valve area <1 cm(2)) and the indication for TAVI were included. Aortic valve prosthesis was inserted retrograde. Examinations of study patients were performed before, 30 days, and 6 months after TAVI and comprised measurement of B-type natriuretic peptide and echocardiography. Severe prosthesis-patient mismatch was defined as an indexed effective aortic valve area < or =0.65 cm(2)/m(2).

RESULTS

In 39 patients, follow-up examinations were performed after TAVI. Severe prosthesis-patient mismatch seldom occurred (n = 1), but mild to moderate aortic valve regurgitation due to paravalvular leaks was common (n = 24, 62%). After 6 months, left ventricular mass index declined (158 +/- 46 vs 138 +/- 45 g/m(2), P = .001), and peak early diastolic mitral annular velocity (E') and peak systolic mitral annular velocity (S') increased (P = .004 and P < .001, respectively). B-type natriuretic peptide levels decreased (744 +/- 708 at baseline vs 367 +/- 273 at 30 days, P = .003, 279 +/- 186 pg/mL at 6 months, P = .001). Left ventricular diameters and ejection fraction remained unchanged.

CONCLUSION

Despite the high incidence of paravalvular regurgitation after TAVI, hemodynamic results were favorable. Furthermore, TAVI had positive effects on left ventricular remodeling and improved neurohormonal activity, myocardial hypertrophy, and diastolic function.

Midterm Evaluation of Hemodynamics of the Top Hat Supraannular Aortic Valve

The CarboMedics Top Hat supraannular aortic valve provides an orifice-to-annulus ratio of 1:1 in most patients, and enhances patient outcomes. This study compared the midterm echocardiographic parameters of 52 patients undergoing aortic valve replacement with a Top Hat valve with those in other studies of Top Hat or CarboMedics intraannular valves. Echocardiography was performed 6–48 months after surgery with Top Hat sizes 21-27. Parameters evaluated included mean gradient, peak gradient, effective orifice area, and effective orifice area index. Preoperative and postoperative echocardiographic measurements were compared in 38 patients with aortic valve stenosis. Hemodynamic data were comparable to those of other studies, but the Top Hat prosthesis implanted was significantly larger (by a mean of 3.29 mm) than the valve size indicated using an intraannular valve sizer in 48 patients. Mean effective orifice area improved significantly from 0.73 cm2 preoperatively to 2.04 cm2 postoperatively. In patients with preoperative aortic valve stenosis, postoperative mean peak gradient was significantly reduced. The larger orifice-to-annulus ratio of the Top Hat valve improved hemodynamic parameters assessed by echocardiography up to 4 years postoperatively, with a lower transvalvular gradient, hence decreased left ventricular workload.

The emerging role of exercise testing and stress echocardiography in valvular heart disease

Exercise testing has an established role in the evaluation of patients with valvular heart disease and can aid clinical decision making. Because symptoms may develop slowly and indolently in chronic valve diseases and are often not recognized by patients and their physicians, the symptomatic, blood pressure, and electrocardiographic responses to exercise can help identify patients who would benefit from early valve repair or replacement. In addition, stress echocardiography has emerged as an important component of stress testing in patients with valvular heart disease, with relevant established and potential applications. Stress echocardiography has the advantages of its wide availability, low cost, and versatility for the assessment of disease severity. The versatile applications of stress echocardiography can be tailored to the individual patient with aortic or mitral valve disease, both before and after valve replacement or repair. Hence, exercise-induced changes in valve hemodynamics, ventricular function, and pulmonary artery pressure, together with exercise capacity and symptomatic responses to exercise, provide the clinician with diagnostic and prognostic information that can contribute to subsequent clinical decisions. Nevertheless, there is a lack of convincing evidence that the results of stress echocardiography lead to clinical decisions that result in better outcomes, and therefore large-scale prospective randomized studies focusing on patient outcomes are needed in the future.