Clinical outcome in patients with 19-mm and 21-mm St. Jude aortic prostheses: comparison at long-term follow-up

The Perceval Sutureless Bioprosthetic Aortic Valve: Evolution of Surgical Valve Technology

OBJECTIVE

The surgical treatment of aortic stenosis continues to evolve, and sutureless aortic valve replacement (SUAVR) is an emerging technology. With the Perceval S (Corcym, London, UK) as the only true sutureless valve on the market, the objective of this review is to analyze the current literature on Perceval S. Focusing on valve design and deployment as well as applications of the technology for challenging pathology, clinical outcomes are assessed, including a comparison with transcatheter AVR (TAVR).

METHODS

PubMed and MEDLINE were searched by 3 authors for studies analyzing SUAVR from inception to May 19, 2023.

RESULTS

SUAVR facilitates minimally invasive surgery and offers an alternative strategy for patients with small aortic annuli. It also has a time-saving advantage for patients who require complex operations. SUAVR results in excellent long-term morbidity, mortality, durability, and hemodynamic function. In comparison with conventional surgical AVR (SAVR), SUAVR does have a greater risk of postoperative pacemaker implantation; however, increasing user experience and refinements in implantation technique have contributed to reductions in this outcome. SUAVR results in morbidity and mortality that is similar to rapid-deployment AVR. Midterm outcomes are superior to TAVR; however, further robust investigation into all of these comparisons is ultimately necessary.

CONCLUSIONS

SUAVR bridges the gap in technology between SAVR and TAVR. The application of this exciting technology will undoubtedly grow in the coming years, during which additional investigation is paramount to optimize preoperative planning, valve deployment, and reintervention strategies.

Aortic root enlargement: When and how

Aortic valve replacement is the definitive management for severe aortic stenosis. Intraoperatively, an aortic root enlargement (ARE) may be used to facilitate the implementation of a suitably sized prosthetic valve. This is to prevent patient prosthesis mismatch (PPM), a condition that causes a left ventricular outflow obstruction. There are four main techniques that are used to perform ARE, namely, Nicks, Manouguian, Nunez (modified Manouguian), and Kanno-Rastan procedures. They each involve incisions through different anatomical structures and allow a variety of valve sizes to be implanted. Studies prove that ARE effectively reduces the incidence of PPM. In addition, they show that there is no definitive link between ARE and perioperative mortality or other complications. There is a scarcity of literature exploring the comparative outcomes of each surgical technique. Therefore, further research is warranted for these procedures to be compared adequately. This review aims to summarise the available literature surrounding ARE with respect to three main questions. (1) What are the indications for ARE, (2) what surgical techniques exist to facilitate ARE, and (3) are there significant differences in patient outcomes when these surgical techniques are employed?

Computed Tomography Annular Dimensions: A Novel Method to Compare Prosthetic Valve Hemodynamics

BACKGROUND

The Cardiac Surgical Societies Valve Labeling Task Force consensus document acknowledged inconsistent sizing and labeling of prosthetic heart valves. This study compared the labeled size, internal diameter, and hemodynamics of different surgical and transcatheter valve types implanted into the same size annulus, measured by preprocedural computed tomography (CT).

METHODS

Patients were retrospectively sorted into 3 CT annular diameter size groups: small (less than 23 mm), medium (23 to less than 26 mm), and large (26 mm or greater). Surgical valves were sorted into 4 categories based on tissue and design: (stentless porcine, standard stented bovine, wraparound stented bovine, and stented porcine). Comparisons were made within the surgical types and with a transcatheter valve. Echocardiograms were independently assessed and CTs were centrally measured.

RESULTS

We analyzed 726 surgical and 923 transcatheter valve paired data sets. Among the various valve types implanted into the same size CT annulus, there were significant differences regarding size, internal diameter, and hemodynamics within all 3 size groups. Root enlargement procedures occurred in 1.2% with no differences across valve types or size groups. Transcatheter valve hemodynamics were similar to stentless valves and were significantly better than all stented valves. There was no difference in hemodynamics between the 2 bovine stented valve types, and stented porcine valves were inferior to all valve types.

CONCLUSIONS

This study documents that prosthetic heart valve sizing and labeling inconsistencies exist. Use of preoperative CT annular dimensions is the most accurate method to compare size, internal diameter, and hemodynamics of bioprosthetic aortic valves because it compares values among various valve types implanted into the same size annulus.

Soft robotic in the construction of prosthetic heart valve: a novel approach

In this study, we describe the design, fabrication and computational testing of a new prosthetic device for aortic valve replacement. The device is an active stent composed of a silicone rubber during initial prototyping, with adaptation towards a hydrogel, poly-vinyl alcohol reinforced with bacterial cellulose nanofibres underway. The nature of the stent is soft robotic (SR), where an increase in internal pressure of the pneumatic network causes an increase in the internal diameter of the device. When working in tandem with the SR heart valve, described briefly, pulsations of the blood and the energy gained from ventricular pressure actuates the valve-and-stent combination. This increases the effective orifice area of the entire device and addresses an issue with small sized heart valves facing prosthesis-patient mismatch.

Men are from mars, women are from venus: Factors responsible for gender differences in outcomes after surgical and trans-catheter aortic valve replacement

Females suffer higher operative (30-day) mortality than males after surgical aortic valve replacement (SAVR). In contrast, outcomes after trans-catheter aortic valve replacement (TAVR) seem to favor females, both in terms of procedural mortality, and more prominently, medium to long-term survival. With an ever-greater number of TAVR procedures being performed, an understanding of factors responsible for gender differences in outcomes after the two AVR modalities is critical for better patient selection. Current evidence suggests that this gender difference in outcomes after SAVR and TAVR stems from differences in baseline risk profiles, as well as inherent anatomic/physiological differences between genders. This review attempts to examine these clinical and physiological factors, with a goal of guiding better patient selection for each AVR modality, and to highlight areas that beg further investigation.

Aortic Valve Replacement in Elderly Patients With Small Aortic Annulus: Results With Three Different Bioprostheses

Objectives

Aortic valve replacement (AVR) in patients with small aortic annulus (diameter ≤21 mm) is considered a challenging scenario because of technical aspects and the high risk of patient-prosthesis mismatch (PPM). The choice of the appropriate prosthesis is crucial, and at the moment, an ideal device has yet to be identified. We compare clinical and hemodynamic results after AVR with three bioprostheses with different design and characteristics.

Methods

We retrospectively evaluated 76 consecutive patients from two cardiac surgery centers who underwent AVR (Trifecta = 24; Edwards INTUITY Elite valve system = 26, and Perceval = 26) for severe aortic stenosis between 2013 and 2017. Patients selected were older than 75 years and with an annulus diameter ≤21 mm at preoperative echocardiogram. Reinterventions and combined procedures were excluded. Minimally invasive AVR was performed in 44 (57.8%) patients. Telephonic interview was obtained at 2.9 ± 0.5 years and echocardiographic follow-up at 2.2 ± 0.8 years.

Results

Clinical outcome was similar in the three groups. At follow-up, Trifecta patients presented significantly higher peak and mean transprosthetic pressure gradients ( P = 0.04 and 0.01). Effective orifice area and left ventricular mass regression were comparable, although an advantage was observed in Perceval patients without reaching the statistical significance. Incidence of moderate ( P = 0.2) and severe PPM ( P = 0.7) was comparable.

Conclusions

Despite higher postoperative pressure gradients observed with the Trifecta valve, all three prostheses (Trifecta, Edwards INTUITY Elite, and Perceval) have proven to be reliable when implanted in small aortic annuli, with good clinical outcome and favorable left ventricular mass regression.

The Prognostic Significance of Patient-Prosthesis Mismatch after Aortic Valve Replacement

Patient-prosthesis mismatch (PPM) is a controversial issue in current clinical practice. PPM has been reported to have a negative impact on patients’ prognosis after aortic valve replacement in several studies, showing increased all-cause and cardiac mortality. Moreover, a close relationship has recently been described between PPM and structural valve deterioration in biological prostheses. In patients at risk for PPM, several issues should be considered, and in the current era of cardiac surgery, preoperative planning should consider the different types of valves available and the various surgical techniques that can be used to prevent PPM. The present paper analyses the state of the art of the PPM issue.

Can Perceval sutureless valve reduce the rate of patient-prosthesis mismatch?†

OBJECTIVES

The aim of this study is to compare the theoretical incidence of patient-prosthesis mismatch (PPM) in patients undergoing a sutureless or a sutured aortic valve replacement using an exact statistical matching.

METHODS

Between May 2012 and March 2016, 65 patients with severe symptomatic aortic stenosis underwent a sutureless aortic valve replacement with the Perceval bioprosthesis in 2 centres. Moreover, 177 aortic valve replacements with conventional sutured bioprosthesis were performed between August 2003 and September 2015. Perceval and sutured patients were 1:1 exactly matched for sex and body surface area (BSA), resulting in 62 couples (sutureless: BSA 1.77 ± 0.16 m 2 , female 62.9% vs sutured: BSA 1.77 ± 0.15 m 2 , female 62.9%).

RESULTS

After matching, the indexed effective orifice area was 1.50 ± 0.18 cm 2 /m 2 and 0.81 ± 0.19 cm 2 /m 2 in the sutureless and the sutured group, respectively ( P  < 0.001). No PPM occurred in patients who received a Perceval bioprosthesis ( n  = 62). In the sutured group ( n  = 62), 38 patients (61.3%) developed a PPM, which was moderate in 41.9% ( n  = 26) and severe in 19.4% ( n  = 12) ( P  < 0.001).

CONCLUSIONS

The indexed effective orifice area of the sutureless group was significantly larger than in the sutured one. The incidence of PPM with the conventional sutured biprosthesis was 61.3%, while it decreases to 0% in the sutureless group. No PPM was reported in the sutureless valve group. Therefore, the Perceval sutureless valve provides larger effective orifice areas compared to the sutured conventional bioprosthesis and could be considered as a good option to reduce the risk of a PPM.

Intraoperative Transesophageal and Postoperative Transthoracic Echocardiographic Evaluation of a Mechanical Heart Valve Prosthesis Implanted at Aortic Position

OBJECTIVE

The aims of this study were to evaluate the intraoperative transesophageal echocardiographic (iTEE) characteristics and Doppler flow profile of aortic Chitra heart valve prosthesis (CHVP) under stable hemodynamic and loading conditions, and to compare and correlate the iTEE data with the postoperative transthoracic echocardiography (TTE) data obtained at 48 hours (TTE₁) and 3 months (TTE₂) after the surgery.

DESIGN

Prospective, observational study.

SETTING

University-level tertiary referral hospital.

PARTICIPANTS

Forty patients between 18 years and 65 years of age undergoing elective aortic valve replacement (AVR) using CHVP during the period January 2015 to August 2016.

INTERVENTIONS

After obtaining permission from institutional ethics committee, 40 patients undergoing elective AVR were studied prospectively. The iTEE examination was performed in the pre-cardiopulmonary bypass (CPB) and post-CPB period in all the study subjects. CHVP was subjected to iTEE two-dimensional (2D) echo, color Doppler, and spectral Doppler evaluation under stable hemodynamic and loading condition in the post-CPB period after the administration of protamine. The CHVP were re-evaluated using TTE in all the patients 48 hours after the surgery (TTE₁) and 3 months after the surgery (TTE₂). The iTEE and postoperative TTE Doppler values were compared and correlated.

MEASUREMENTS AND MAIN RESULTS

The CHVP could be imaged adequately and interrogated with Doppler in all the patients. None of the patients had restriction of occluder mobility or unstable seating of the valve. The intraoperative flow dependent (peak velocity [PV] and mean pressure gradient [MPG]) and less flow dependent (Doppler velocity index, acceleration time, acceleration time/ejection time, effective orifice area [EOA] and indexed EOA) Doppler parameters of CHVP were measured as per the American Society of Echocardiography recommendations. The PV and MPG of CHVP measured by iTEE showed no statistical difference (p > 0.05) and were in limits of agreement when compared with TTE₁ and TTE₂ data.

CONCLUSION

The iTEE features of CHVP were found compliant with the criteria set by the ASE defining normal functioning of an aortic valve prosthesis. The iTEE Doppler parameters obtained under stable loading conditions strongly predicted the postoperative values of Doppler parameters on TTE examination. The iTEE Doppler values can be used as the reference values for the postoperative follow up studies.

Early and Mid-term Outcome of the St. Jude Medical Regent 19-mm Aortic Valve Mechanical Prosthesis. Functional and Haemodynamic Evaluation

BACKGROUND AND OBJECTIVES

The aim of the present study is to report the early and mid-term clinical and haemodynamic results of the St Jude Medical Regent 19-mm aortic mechanical prothesis (SJMR-19).

MATERIALS AND METHODS

Between January 2002 and January 2012, 265 patients with aortic valve disease underwent AVR (Aortic Valve Replacement) with a SJMR-19 (St Jude Medical Regent Nr.19). There were 51 males. Mean age was 67.5±12.72years and mean body surface area (BSA) was 1.67±0.14m2. Thirty-six patients required annulus enlargement. The mean follow-up was 34.5±18.8months (range 6-60 months). All patients underwent echocardiographic examination at discharge and within 1 year after surgery.

RESULTS

There were 14 (5.3%) hospital deaths. Six of the hospital deaths were identified in patients undergoing reoperation, significantly higher than patients undergoing first time operation (p=0.0001). Also the postoperative mortality was significantly higher in patients undergoing annulus enlargement versus patients not requiring annulus enlargement (p=0.02). The mean transprosthesis gradient at discharge was 19±9mmHg. At 6 months follow-up the mean NYHA FC class was 1.6±0.5 significantly lower than preoperatively 2.4±0.75 (p <0.0001). The M-TPG was 15.2±6.5mmHg within 1 year after surgery. Left ventricular mass (LVM) and indexed left ventricular mass (LVM_i) were significantly lower than preoperatively The actuarial survival and cumulative freedom from reoperation at 1, 2 and 3 years follow-up were 99.5%, 97.5%, 96.7% and 99.2%, 96.5%, 94.5% respectively. The cumulative actuarial free-events survival at 4 years was 92%. The Cox model identified age (p=0.015), LVEF≤35% (p=0.043), reoperation (p=0.031), combined surgery (p=0.00002), and annulus enlargement (p=0.015) as strong predictors for poor actuarial free-major events survival.

CONCLUSIONS

The SJMR-19 offers excellent postoperative clinical, haemodynamic outcome and LVM_i reduction in patients with small aortic annulus. These data demonstrate that the modern St Jude small mechanical protheses do not influence the intermediate free-reoperation survival.

Does patient-prosthesis mismatch after aortic valve replacement affect survival and quality of life in elderly patients?

BACKGROUND

To evaluate the impact of patient-prosthesis mismatch (PPM) on survival, functional status, and quality of life (QoL) after aortic valve replacement (AVR) with small prosthesis size in elderly patients.

METHODS

Between January 2005 and December 2013, 152 patients with pure aortic stenosis, aged at least 75 years, underwent AVR, with a 19 or 21 mm prosthetic heart valve. PPM was defined as an indexed effective orifice area less than 0.85 cm/m. Median age was 82 years (range 75-93 years). Mean follow-up was 56 months (range 1-82 months) and was 98% complete. Late survival rate, New York Heart Association functional class, and QoL (RAND SF-36) were assessed.

RESULTS

Overall, PPM was found in 78 patients (53.8%). Among them, 42 patients (29%) had an indexed effective orifice area less than 0.75 cm/m and 17 less than 0.65 cm/m (11.7%). Overall survival at 5 years was 78 ± 4.5% and was not influenced by PPM (P = NS). The mean New York Heart Association class for long-term survivors with PPM improved from 3.0 to 1.7 (P < 0.001). QoL (physical functioning 45.18 ± 11.35, energy/fatigue 49.36 ± 8.64, emotional well being 58.84 ± 15.44, social functioning 61.29 ± 6.15) was similar to that of no-PPM patients (P = NS).

CONCLUSION

PPM after AVR does not affect survival, functional status, and QoL in patients aged at least 75 years. Surgical procedures, often time-consuming, contemplated to prevent PPM, may therefore be not justified in this patient subgroup.

Moderate Patient-Prosthesis Mismatch Has No Negative Effect on Patients' Functional Status After Aortic Valve Replacement With CarboMedics Prosthesis

Background:

Patient-prosthesis mismatch (PPM) after aortic valve replacement (AVR) is the subject of continuing debate in the cardiac surgery field.

Objectives:

The aim of this study was to evaluate the frequency and severity of patient-prosthesis mismatch (PPM) and the functional status of patients undergoing aortic valve replacement (AVR) using a CarboMedics prosthesis in the mid-term follow up.

Patients and Methods:

We retrospectively studied 66 consecutive patients who were referred to AVR with a CarboMedics prosthesis at the Rajaie cardiovascular medical and research center, a university referral hospital in Tehran, Iran. The severity of PPM as well as clinical and echocardiographic parameters and the patients’ New York heat association (NYHA) functional classification status, operative data and postoperative complications, and mortality in a mid-term (4 - 5 months) follow up period was assessed. Severe PPM was defined as the effective orifice area (EOA) indexed to the patient’s body surface area (BSA) < 0.65 cm²/m² and moderate PPM was defined as the indexed effective orifice area (IEOA) between 0.65 and 0.85 cm²/m².

Results:

Of the 66 studied patients, 39 were male and 27 were female. The mean age of the patients was 43 ± 17 with a range of 6 - 76 years. Implanted sizes of the CarboMedics AV prosthesis in 22 patients were 19 and 21 mm, and in 44 patients were 23 and 25 mm. Eleven patients had moderate PPM (IEOA < 0.85 cm²/m²) and 55 of them did not have PPM (IEOA ≥ 0.85 cm²/m²). There were no statistically significant differences between the two groups in the echocardiographic trans-aortic pressure gradients (35.6 ± 19 vs. 23.2 ± 16 mmHg; P = 0.061) and the mean NYHA functional classification (1.10 ± 0.3 vs. 1.01 ± 0.10; P = 0.074) after AVR in the mid-term follow up.

Conclusions:

Moderate PPM has no negative effect on echocardiographic trans-aortic pressure gradients or the patients’ NYHA functional status after AVR with a CarboMedics prosthesis in the mid-term follow up.

Does the St. Jude Regent 17-mm Offer Better Outcomes Than the Hemodynamic Plus 17-mm Aortic Valve Mechanical Prothesis?

OBJECTIVE

The aim of the present study is to report the early and mid-term clinical and hemodynamic results of a prospective trial investigating the clinical performance of the St. Jude Medical Regent 17 mm (SJMR-17) versus St. Jude Medical Hemodynamic Plus 17 mm (SJMHP-17).

MATERIALS AND METHODS

Between January 2000 and August 2013, 20 patients (Group I) with aortic valve (AV) stenosis underwent first time AV replacement with a SJMR-17 and nine patients (Group II) underwent AV replacement with a SJMHP-17. The mean follow-up was 58 ± 31 months.

RESULTS

There was one death in Group I. The end-diastolic IVS thickness and end-systolic posterior left ventricle (LV) wall thickness was reduced significantly in boths groups (p = 0.001 and p = 0.006 in Group I and p = 0.007 and p = 0.011 in Group II). The peak and mean transprosthesis gradients (P-TPG and M-TPG) were 29 ± 6.8 mmHg and 17.5 ± 4.5 mmHg in Group I, significantly lower than in Group II (55.2 ± 19.7 mmHg and 28.8 ± 7.7 mmHg). The postoperative left ventricular mass (LVM) and indexed left ventricular mass (LVMi) were reduced significantly in both groups versus the preoperative values. The postoperative LVMi was 114.5 ± 10.6 g/m(2) in Group I versus 127 ± 8 g/m(2) in Group II (p = 0.01). With dobutamine, heart rate, left ventricular ejection fraction, cardiac output, transprosthesis peak, and mean gradients increased significantly in both groups, however, the P-TPG and M-TPG were significantly higher in Group II (p = 0.026 and p = 0.022) despite a non-significant increase of the indexed effective orifice area.

CONCLUSIONS

The SJMR-17 can be employed with satisfactory postoperative clinical and hemodynamic outcomes in patients with small aortic annulus, especially in elderly patients offering better outcome than SJMHP-17.

Ross-Konno procedure for the surgical treatment of prosthesis-patient mismatch after prosthetic aortic valve replacement

The Ross-Konno procedure has become a widely recognized surgical method for the treatment of complex left ventricular outflow tract obstruction (LVOTO) in patients of younger age. We applied this method in two young females who presented following mechanical aortic valve replacement with severe prosthesis-patient mismatch (PPM) resulting in significant gradient across the left ventricular outflow tract and congestive heart failure. In both cases the postoperative course was uneventful with immediate improvement in clinical symptoms. Both patients remain in excellent clinical and hemodynamic condition four and six years after the Ross-Konno procedure.

Update on aortic valve prosthesis-patient mismatch in Japan

The influence of aortic valve prosthesis-patient mismatch (VP-PM) on the clinical outcome has been an ongoing controversy. The reported prevalence of VP-PM after aortic valve replacement (AVR) ranges widely between 20 and 70 %. The inconsistent impact of VP-PM on short-term and long-term mortality, regression of left ventricular (LV) hypertrophy, and exercise capacity may be explained by differences of the patient populations, the definition of VP-PM, and the use of different prostheses. Moreover, many factors other than the severity of VP-PM should be taken into account when considering its impact on individual patients after AVR. Although the concept of VP-PM is easy to understand, it cannot be applied to the whole patient population. In Japan, the age of the candidates for AVR has increased markedly in recent years, but almost all elderly patients with a small BSA (<1.6 m(2)) have received newer-generation prostheses with a small outer diameter and large effective orifice area. Indeed, previous studies of Japanese patients have demonstrated that VP-PM was no more than moderate in most cases and its impact on clinical outcomes was generally acceptable. Although severe VP-PM is infrequent and its clinical implications are still unproven in elderly Japanese patients, it would seem reasonable to try to prevent severe VP-PM. Thus, VP-PM itself cannot be accepted as an independent risk factor in Japanese patients, but the useful preventive strategies for severe VP-PM in inactive very elderly persons remain controversial. The implantation of newer-generation biological or mechanical prostheses with or without aortic annular enlargement should be considered according to the characteristics of the patient and the risk-benefit ratio for carrying out a particular procedure in an individual patient.

Valve prosthesis-patient mismatch (VP-PM): a long-term perspective

The concept/phenomenon of valve prosthesis/patient mismatch (VP-PM), described in 1978, has stood the test of time. From that time to 2011, VP-PM has received a great deal of attention but studies have come to varying conclusions. This is largely because of the determination of prosthetic heart valve area [called effective orifice area index (EOAi)] by projection rather than by actual measurement, variable criteria to assess severity of EOAi and the timing of determination of EOAi. All prosthetic heart valves have some degree of VP-PM which must be placed in a proper clinical perspective. This can be done by determining its effects on function and outcomes. For mortality one needs to focus especially on severe/critical degree of VP-PM and determine the cause of death was due to VP-PM. For the period "beyond 2011" a road map is suggested that will have uniformity of assessment of VP-PM and a focusing on the important goals of VP-PM.

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.

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.

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 17-mm St. Jude Medical Regent valve is a valid option for patients with a small aortic annulus

BACKGROUND

When aortic valve replacement is performed in patients with a small aortic annulus, prosthesis-patient mismatch is of concern. Such prosthesis-patient mismatch may affect postoperative clinical status and survival. We investigated the outcomes of isolated aortic valve replacement performed with a 17-mm mechanical prosthesis in patients with aortic stenosis.

METHODS

Twenty-three patients with aortic stenosis (mean age, 74.6 +/- 6.3 years) underwent isolated aortic valve replacement with a 17-mm St. Jude Medical Regent prosthesis. Mean body surface area was 1.41 +/- 0.13 m(2). Preoperative echocardiography yielded a mean aortic valve area of 0.36 +/- 0.10 cm(2)/m(2), a mean left ventricular-aortic pressure gradient of 68.4 +/- 25.3 mm Hg, and a mean left ventricular mass index of 200 +/- 69 g/m(2).

RESULTS

There was no operative mortality, and there were no valve-related events. Echocardiography at 14.0 +/- 10.0 months after aortic valve replacement showed a significant increase in the mean effective orifice area index (0.95 +/- 0.24 cm(2)/m(2)), decrease in the mean left ventricular-aortic pressure gradient (17.4 +/- 8.2 mm Hg), and decrease in the mean left ventricular mass index (124 +/- 37 cm(2)/m(2)). Prosthesis-patient mismatch (effective orifice area index < 0.85 cm(2)/m(2)) was present in 8 patients at discharge. In these patients as well as in those without prosthesis-patient mismatch, the left ventricular mass index decreased remarkably during follow-up.

CONCLUSIONS

Aortic valve replacement with a 17-mm Regent prosthesis appears to provide satisfactory clinical and hemodynamic results in patients with a small aortic annulus. Remarkable left ventricular mass regression during follow-up was achieved irrespective of the effective orifice area index at discharge.

Prediction of valve prosthesis-patient mismatch prior to aortic valve replacement: which is the best method?

BACKGROUND

To predict the occurrence of valve prosthesis-patient mismatch (VP-PM) after aortic valve replacement (AVR), the surgeon needs to estimate the postoperative effective orifice area index (EOAI).

AIM

To compare different methods of predicting VP-PM.

METHODS

The effective orifice area (EOA) of 383 patients who had undergone AVR between July 2000 and January 2005 with various aortic valve prostheses was obtained echocardiographically 6 months after the operation. We tested the efficacy of (1) EOAI calculated from the echo data obtained in our own laboratory, (2) indexed geometric orifice area, (3) EOAI estimated from charts provided by prosthesis manufacturers (which are based either on in vitro or on echo data) and (4) EOAI estimated from reference echo data published in the literature to predict VP-PM.

RESULTS

Sensitivity and specificity to predict VP-PM were 53% and 83% (method 1), 80% and 53% (charts based on echo data, parts of method 3) and 71% and 67% (method 4) using reference data derived from echocardiographic examinations. The sensitivity of method 2 and of charts based on in vitro data (parts of method 3) to predict VP-PM was 0-17%. The incidence of severe VP-PM could be reduced from 8.7% to 0.8% after the introduction of the systematic estimation of the EOAI at the time of operation (p = 0.003, method 1).

CONCLUSIONS

The best method of predicting VP-PM is the use of mean (SD) EOAs derived from echocardiographic examinations, whereas the use of in vitro data or the geometric orifice area is unreliable. After the surgeon's anticipation of VP-PM prior to AVR, the incidence of VP-PM could be reduced.

Risk Factors for Postoperative Heart Failure in Patients Operated on for Aortic Stenosis

BACKGROUND

Risk factors for postoperative heart failure (PHF) have not been specifically studied in valve surgery although it has been acknowledged that patient variables may have a more profound influence on postoperative outcome than valve-related factors.

METHODS

All patients undergoing isolated aortic valve replacement for aortic stenosis from January 1995 to December 2000 in the southeast region of Sweden were studied (n = 398). Forty-five patients with aortic valve replacement required treatment for PHF. Univariate and multivariate logistic regression analysis was carried out to identify risk factors for PHF.

RESULTS

Thirty-day mortality was 6.7% versus 1.4% for patients with and without PHF, respectively (p = 0.05). With regard to clinical presentation of aortic stenosis, angina was associated with reduced risk, whereas history of congestive heart failure increased the risk for PHF. Five preoperative (hypertension, history of congestive heart failure, severe systolic left ventricular dysfunction, pulmonary hypertension, preoperative hemodynamic instability) and two intraoperative (aortic cross-clamp time, intraoperative myocardial infarction) variables were identified as independent risk factors for PHF. Patient-prosthesis mismatch did not influence the risk of PHF significantly.

CONCLUSIONS

Postoperative heart failure was associated with a marked increase in postoperative mortality and morbidity. Risk factors for PHF were variables indicating preexisting myocardial dysfunction, increased right or left ventricular afterload, and intraoperative myocardial injury. Our results highlight issues concerning cross-clamp time and myocardial protection, particularly for patients with preoperatively compromised myocardial function. Asymptomatic patients with significant aortic stenosis should be considered for surgery before substantial echocardiographic evidence of left ventricular dysfunction or increased pulmonary artery pressure develops.

Impact of Prosthesis-Patient Mismatch on Cardiac Events and Midterm Mortality After Aortic Valve Replacement in Patients With Pure Aortic Stenosis

Background— Prosthesis-patient mismatch (PPM) occurs when the effective orifice area (EOA) of the prosthesis being implanted is too small in relation to body size, thus causing abnormally high transvalvular pressure gradients. The objective of this study was to examine the midterm impact of PPM on overall mortality and cardiac events after aortic valve replacement in patients with pure aortic stenosis.

Methods and Results— The indexed EOA (EOAi) was estimated for each type and size of prosthesis being implanted in 315 consecutive patients with pure aortic stenosis. PPM was defined as an EOAi ≤0.80 cm 2 /m 2 and was correlated with overall mortality and cardiac events. PPM was present in 47% of patients. The 5-year overall survival and cardiac event-free survival were 82±3% and 75±4%, respectively, in patients with PPM compared with 93±3% and 87±4% in patients with no PPM ( P ≤0.01). In multivariate analysis, PPM was associated with a 4.2-fold (95% CI, 1.6 to 11.3) increase in the risk of overall mortality and 3.2-fold (95% CI, 1.5 to 6.8) increase in the risk of cardiac events. The other independent risk factors were history of heart failure, NHYA class III-IV, severe left ventricular hypertrophy, and absence of normal sinus rhythm before operation.

Conclusions— PPM is an independent predictor of cardiac events and midterm mortality in patients with pure aortic stenosis undergoing aortic valve replacement. As opposed to other risk factors, PPM may be avoided or its severity may be reduced with the use of a preventive strategy at the time of operation.

Impact of Prosthesis-Patient Mismatch on Long-Term Survival in Patients With Small St Jude Medical Mechanical Prostheses in the Aortic Position

Background— The impact of aortic prosthesis-patient mismatch (P-PtM) on long-term survival is unclear.

Methods and Results— Between 1985 and 2000, 388 patients at Mayo Clinic in Rochester, Minn, underwent aortic valve replacement (AVR) with 19- or 21-mm St Jude Medical prostheses and had transthoracic echocardiography within 1 year after AVR. Mean age of patients was 62±13 years; 69% were female. Prosthesis effective orifice area (EOA) was derived from the continuity equation. P-PtM was classified as severe (indexed EOA ≤0.60 cm 2 /m 2 ), moderate (0.60 cm 2 /m 2 <indexed EOA≤0.85 cm 2 /m 2 ), or not hemodynamically significant (indexed EOA >0.85 cm 2 /m 2 ). P-PtM was severe in 66 patients (17%), moderate in 168 (43%), and not hemodynamically significant in 154 (40%). Patients with severe P-PtM had a significantly larger body surface area ( P <0.0001), higher mean gradient ( P <0.0001), lower preoperative ( P <0.0001) and postoperative ( P <0.0001) ejection fractions, and lower stroke volume ( P <0.0001) and more often received a 19-mm prosthesis ( P =0.0008) than patients with moderate or no hemodynamically significant mismatch. For patients with severe mismatch, 5-year survival rates (72±6%) and 8-year survival rates (41±8%) were significantly less than for patients with moderate mismatch (80±3% and 65±5%; P =0.026) or no hemodynamically significant mismatch (85±3% and 74±5%; P =0.002). On multivariate analysis after adjustment for other predictors of outcome, severe mismatch was associated with higher mortality (hazard ratio 2.18; 95% confidence interval 1.24 to 3.85; P =0.007) and higher incidence of congestive heart failure (hazard ratio 3.1; 95% confidence interval 1.3 to 7.4; P =0.009) than no hemodynamically significant mismatch.

Conclusions— Severe P-PtM is an independent predictor of higher long-term mortality and congestive heart failure in patients with small St Jude Medical aortic valve prostheses. For patients undergoing AVR who are at risk of severe mismatch, every effort should be made to use a larger prosthesis or to consider a prosthesis with a larger EOA.

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

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