Impact of Prosthesis–Patient Size on Functional Recovery After Aortic Valve Replacement

Clinical Impact of Patient-Prosthesis Mismatch After Aortic Valve Replacement With a Mechanical or Biological Prosthesis

BACKGROUND

Patient-prosthesis mismatch (PPM) may impair functional capacity and survival after aortic valve replacement. This study aimed to investigate the impact of PPM on long-term survival and quality of life after mechanical and biological aortic valve replacement.

METHODS

This study included 595 consecutive patients who had undergone isolated aortic valve replacement. Patients were divided into 2 groups according to prosthesis type. The baseline and operative characteristics, survival rates, complications, and quality of life of the groups with and without PPM were compared for up to 6 years. The PPM calculation was performed using the effective orifice area value provided by the manufacturer divided by the patient's body surface area.

RESULTS

The moderate to severe PPM rates were 69.8% and 3.7% after biological and mechanical prosthesis implantation, respectively. Mean survival for patients in the biological group who had PPM was statistically significantly shorter (50.2 months [95% CI, 45.2-55.3]) than for patients in the biological group without PPM (60.1 months [95% CI, 55.7-64.4]; P = .04). In the mechanical prosthesis group, there was no difference in mean survival between the subgroup with PPM (66.6 months [95% CI, 58.3-74.9]) and the subgroup without PPM (64.9 months [95% CI, 62.6-67.2]; P = .50). A quality-of-life questionnaire's scores did not differ between the groups.

CONCLUSION

Mismatch is common after biological valve implantation and statistically significantly affects long-term survival and quality of life. If the risk of PPM after implantation of a biological prosthesis is suspected, adopting strategies to avoid PPM at the time of surgery is warranted.

Figure of eight suture technique in aortic valve replacement decreases prosthesis-patient mismatch

BACKGROUND

While the pledget suture technique has been the standard for surgical aortic. valve replacement (AVR), discussion continues regarding the possibility of the nonpledget suture technique to produce superior structural and hemodynamic parameters. This study aims to assess the effectiveness of the figure-of-eight suture technique in AVR, as determined by the incidence of prosthesis-patient mismatch (PPM).

METHODS

We reviewed records of patients (N = 629) who underwent a surgical AVR procedure between January 2011 and July 2018 at a single institution. Indexed effective orifice area values and PPM incidence were calculated from implanted valve size and patient body surface area. Incidence of none, moderate, and severe PPM was compared across AVR suture techniques.

RESULTS

A total of 570 pledget and 59 figure-of-eight patients were compared for incidence of PPM. Patients who received AVR with the pledget suture technique had significantly lower echocardiographic measurements of baseline ejection fraction than patients who had received AVR with the figure-of-eight suture technique (p = 0.003). Patients who received the figure-of eight suture had a 14% decrease in moderate PPM compared to patients who received the pledget suture (p = 0.022). Patients who received the figure-of-eight suture also had a significantly higher rate of no PPM (p = 0.044).

CONCLUSIONS

The use of the figure-of-eight suture technique in AVR can reduce the incidence of moderate PPM. While the pledget suture is the standard technique in AVR, the figure-of-eight suture technique may offer better structural and hemodynamic outcomes, especially for patients with a smaller aortic annulus.

Patient–Prosthesis Mismatch in Contemporary Small-Size Mechanical Prostheses Does Not Impact Survival at 10 Years

Background: The effect of PPM in mechanical prostheses on long-term survival is not well-established. Methods: Patients who received a 21 mm or smaller aortic valve between 2000 and 2011 were retrospectively analyzed (n = 416). Propensity matching was used in order to account for baseline differences in patient subgroups (PPM vs. no PPM; severe PPM vs. no severe PPM). Results: Five- and ten-year survival was 78 ± 3.52% and 64.51 ± 4.51% in patients with PPM, versus 83.3 ± 3.12% and 69.37 ± 4.36% in patients without (p = 0.28) when analyzed at 10.39 ± 5.25 years after the primary procedure. Independent risk factors for impaired survival, after matching, were age, serum creatinine, and severe pulmonary hypertension. Five- and ten-year survival in patients with severe PPM was 73.34 ± 6.01% and 61.76 ± 8.17%, respectively, versus 74.72 ± 5.68% and 67.50 ± 7.09% in those without (p = 0.49), at 8.82 ± 5.17 years after SAVR. Age was the only independent variable that influenced long-term survival when severe PPM was added to the model. Conclusions: PPM or severe PPM does not impact long-term survival up to 10 years in mechanical valve recipients when matching for preoperative variables.

Impact of Flow on Prosthesis-Patient Mismatch Following Transcatheter and Surgical Aortic Valve Replacement

BACKGROUND

Severe prosthesis-patient mismatch (PPM) is diagnosed by an indexed effective orifice area <0.65 cm²/m², which is derived from stroke volume index. We examined the impact of flow, determined by stroke volume index, on severe PPM following transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR).

METHODS

We included SAVR patients from the PARTNER 2A trial (Placement of Aortic Transcatheter Valve 2A) and TAVR patients from the PARTNER 2 S3i (Placement of Aortic Transcatheter Valve 2 S3i) registry. The primary end point was the separate analysis of all-cause death, cardiac death, and rehospitalization at 5 years. Following TAVR and SAVR, we compared the primary end points between severe versus no-severe PPM in all patients, in low flow (LF), and in normal flow. Multivariable analysis was performed to determine variables associated with the end points.

RESULTS

Nine hundred fifty-four TAVR and 726 SAVR patients with PPM and flow data were included. Severe PPM following TAVR was significantly lower compared with SAVR in all patients (9% versus 28%, P<0.0001), in normal flow (5% versus 8%, P=0.04), and in LF (20% versus 42%, P<0.0001). Severe PPM was associated with rehospitalization following TAVR (odds ratio, 1.52 [95% CI, 1.01-2.29], P=0.0456) and SAVR (odds ratio, 1.51 [95% CI, 1.06-2.16], P=0.0237). Severe PPM in LF was independently associated with cardiac death following TAVR (odds ratio, 1.85 [95% CI, 1.06-3.23], P=0.0308). Following SAVR, severe PPM in LF and low ejection fraction was associated with increased cardiac death (35.26% versus 12.51%, P=0.01) and rehospitalization (37.59% versus 15.46%, P=0.006) compared with severe PPM in LF and preserved ejection fraction, respectively. Severe PPM in normal flow was not associated with clinical outcomes despite higher gradients and smaller valves compared with severe PPM in LF.

CONCLUSIONS

Severe PPM is more common following SAVR compared with TAVR. Regardless of the implanted valve size or gradient, severe PPM impacts mortality only in patients with LF following TAVR and LF and low ejection fraction following SAVR. Severe PPM in normal flow is not associated with poor outcomes. Registration: URL: https://www.clinicaltrials.gov; Unique identifiers: NCT01314313 and NCT02687035.

Long-Term Results (up to 20 Years) of 19 mm or Smaller Prostheses in the Aortic Position. Does Size Matter? A Propensity-Matched Survival Analysis

Background: The long-term performance of prostheses in the small aortic root is still unclear. Methods: Patients who received a 21 mm or smaller aortic valve between 2000–2018 were retrospectively analyzed. Propensity matching was used in order to account for baseline differences in 19 mm vs. 21 mm valve subgroups. Results: Survival at 10 years was 55.87 ± 5.54% for 19 mm valves vs. 57.17 ± 2.82% for 21 mm ones in the original cohort (p = 0.37), and 58.69 ± 5.61% in 19 mm valve recipients vs. 53.60 ± 5.66% for 21 mm valve subgroups in the matched cohort (p = 0.55). Smaller valves exhibited significantly more patient–prothesis mismatch (PPM) than larger ones (87.30% vs. 57.94%, p < 0.01). All-cause mortality was affected by PPM at 10 years (52.66 ± 3.28% vs. 64.38 ± 3.87%, p = 0.04) in the unmatched population. This difference disappeared, however, after matching: survival at 10 years was 51.82 ± 5.26% in patients with PPM and 63.12 ± 6.43% in patients without PPM. (p = 0.14) Conclusions: There is no survival penalty in using 19 mm prostheses in the small aortic root in the current era. Although PPM is more prevalent in smaller sized valve recipients, this does not translate into reduced survival at 10 years of follow-up.

Aortic root widening: “pro et contra”

In patients with a small aortic annulus, the clinical benefits of aortic valve replacement depend on avoidance of patient-prosthesis mismatch as it is associated with reduced overall survival. Aortic root widening or enlargement is a useful technique to implant larger valve prosthesis to prevent patient-prosthesis mismatch. Posterior annular enlargement is the commonest technique used for aortic root enlargement. Consistent enlargement of the aortic root requires more extensive procedures like Manouguian or Konno-Rastan techniques. The patients commonly selected are younger patients with good life expectancy. However, caution is advised in applying this procedure in elderly patients, patients with heavily calcified annulus and when performing concomitant procedures. There is no definitive conclusion on the best material to use for the reconstruction of aortic annulus and aorta in aortic root enlargement procedures.

Predicting exercise capacity recovery immediately after mitral valve surgery

BACKGROUND

This study presents the exercise capacity of postmitral valve surgery patients and determines predictors capable of affecting recovery.

METHODS

A total of 302 patients with mitral regurgitation who had undergone mitral surgery at the Heart Center in Taiwan from 1 August 2013 to 31 December 2015 were included in the present study. Data related to specific predictors of operative outcome were collected, including demographic data, intraoperative factors, exercise tolerance, echocardiogram data, concurrent cardiovascular disease history, comorbidities, lifestyle risk factors, and surgery types. Postoperative exercise capacity was presented as peak oxygen consumption (VO₂ ; mL of O ₂ /kg/min) determined by exercise tests 3 weeks after surgery. Subjects were separated into two groups: a preserved recovery (peak VO ₂  ≥ 65% of predicted VO _2max ) group and a poor recovery group (peak VO ₂  < 65% of predicted VO _2max ). Preliminary univariate analysis was performed to test for possible relationships between predictive variables and exercise capacity. An analysis of all items shown to be significantly different between the two groups was then subjected to multivariate logistic regression analysis. Detected differences with P < .05 were considered significant.

RESULTS

Among the 302 patients sampled, female sex (odds ratio [OR], 2.65; 95% confidence interval [95% CI], 1.58-4.47), obesity (OR, 0.26; 95% CI, 0.10-0.64), sedentary lifestyle (OR, 0.47; 95% CI, 0.28-0.79), and high preoperative New York Heart Association Functional Classification level (OR, 0.52; 95% CI, 0.31-0.87) were significant predictors of poor exercise capacity.

CONCLUSIONS

Without complicated clinical procedures, physicians and medical teams could easily use these items of information to screen the exercise capacity of mitral valve surgery patients and prepare a suitable after surgery plan if needed or request a consultation as early as possible.

Measuring what matters to the patient: health related quality of life after aortic valve and thoracic aortic surgery

With improved outcomes following cardiac surgery, health related quality of life (HRQoL) gains increasing importance for the better judgement of choosing the preferred treatment strategy in the individual patient. The physician perception of patient preferences can differ considerably from actual patient preferences, underlining the importance of gathering evidence of actual patient preferences before and quality of life after cardiac surgery. The objective of the current review is to provide an overview of current insights into the quality of life measurements after aortic valve and thoracic aortic surgery and to provide starting points for the application of HRQoL measurements toward the future. The amount and level of evidence on HRQoL outcomes after aortic valve and thoracic aortic surgery seems to be insufficient. Little has been investigated about the natural course of HRQoL after cardiac surgery, HRQoL outcomes between different surgical strategies, HRQoL outcomes between surgical patients and the general population, the different factors influencing HRQoL after cardiac surgery, and the effect of HRQoL on healthcare costs. More prospective studies should be performed, taking into account the knowledge gaps that need to be filled. Computerized adaptive testing methods through open source programs can be implemented to keep the burden to the patient as low as possible and catalyze the use of these tools. Our cardiovascular surgery community has the responsibility to deliberate how it can proceed to effectively fill in these knowledge gaps, and use this newfound knowledge to improve shared treatment decision making, patient outcomes, and ultimately optimize health care efficiency.

Prosthesis-patient mismatch - what cardiac anesthesiologists need to know?

Prosthesis-patient Mismatch (PPM) is not uncommon with an incidence reported up to 70% after aortic valve (AV) replacement. Severe forms of PPM are less common (up to 20%); PPM can lead to increased short- and long-term morbidity and mortality. It is important to discriminate PPM from other forms of prosthetic valve dysfunction. Sometimes, prosthetic valve degenerative disease may coexist with PPM. Echocardiography plays an important role in the prevention and diagnosis of PPM. Preemptive strategies to prevent PPM include insertion of newer generation prosthetic valves with better hemodynamic characteristics, stentless prosthesis, aortic root enlargement to insert a larger prosthesis, aortic homograft, and transcutaneous AV implantation. We present an illustrative case and review the literature on PPM pertinent to anesthesiologists.

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.

Long-Term Clinical and Echocardiographic Follow-Up of the Freestyle Stentless Aortic Bioprosthesis

Background—

Stentless aortic bioprostheses were designed to provide enhanced hemodynamic performance and potentially greater longevity. The present report describes the outcomes of patients with the Freestyle stentless bioprosthesis followed for ≤18 years.

Methods and Results—

Between 1993 and 2011, 430 patients underwent primary aortic valve replacement with a Freestyle bioprosthesis in the subcoronary position. Mean age was 68.2±8.2 years. All of the clinical and echocardiographic data were collected prospectively. Mean overall follow-up was 9.1±4.4 years and was complete in all of the patients. In-hospital mortality was 3.5% (n=15). Overall, 10- and 15-year survival were 60.7% and 35.0%, respectively. Fifty-one patients required reoperation during follow-up, including 27 for structural valve deterioration (SVD). Overall, freedom from reoperation was 91.0% and 75.0% at 10 and 15 years, whereas freedom from reoperation for SVD was 95.9% and 82.3%, respectively. At 10 and 15 years, freedom from reoperation for SVD was 94.0% and 62.6% for patients <60 years of age and 96.3% and 88.4% for patients ≥60 years of age ( P =0.002). The median time to explant for SVD was 10.7 years. SVD presented mostly as acute, severe aortic insufficiency attributed to leaflet tear (77.8%). The independent risk factors for reoperation for SVD were age <60 years ( P =0.001) and dyslipidemia ( P =0.02).

Conclusions—

Aortic valve replacement with the Freestyle bioprosthesis in a subcoronary position provides good long-term clinical and echocardiographic outcomes for patients >60 years of age. Severe aortic insufficiency with leaflet tear is the major mode of SVD leading to reoperation in these patients.

Marked discrepancy in pressure gradient between Doppler and catheter examinations on Medtronic Mosaic valve in aortic position

A 71-year-old woman underwent aortic valve replacement with 23 mm Medtronic Mosaic Ultra valve 4 years ago because of aortic stenosis. Although she had been asymptomatic since the operation, echocardiography showed 4 m/s of transprosthetic valve flow that implied early prosthetic valve failure. Catheter examination revealed that the mean transvalvular pressure gradient during systole was 15.1 mmHg on simultaneous pressure recording, and calculated valve area 1.82 cm(2). Her body surface area was 1.56 m(2). Prosthetic valve failure and prosthesis-patient mismatch were both denied. The discrepancy between Doppler study data and catheter data seemed to be due to fluid dynamical pressure recovery phenomenon. Net pressure difference between the left ventricle and the aorta may be significantly smaller than that estimated using Bernoulli's equation from transvalvular flow speed in some patients after aortic valve replacement.

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.

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.

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.

Clinical outcome of aortic valve replacement with 16-mm ATS-advanced performance valve for small aortic annulus

BACKGROUND

Various surgical techniques have been proposed to treat small aortic annulus. We have used small-diameter mechanical valves for small aortic annulus. The present study examined aortic valve replacement with small diameter mechanical valves to determine their effectiveness.

METHODS

The study included 67 patients who underwent elective, isolated aortic valve replacement with ATS-Advanced Performance (AP) valves (ATS Medical, Inc, Minneapolis, MN) within our department. The patients were divided into two groups; patients receiving the 16-mm AP valve (16-mm group) and those receiving valves 18-mm AP or larger (>16-mm group).

RESULTS

The mean age of the 16-mm group was significantly higher than that of the >16-mm group. Body surface area was significantly smaller in the 16-mm group than the >16-mm group. We found no significant differences in preoperative conditions between the groups. The effective orifice area index of the mechanical valve was lower in the 16-mm group (0.87+/-0.06 vs 1.12+/-0.13 cm2/m2, p<0.0001). Six patients (40%) in the 16-mm group fell into the category of prosthesis-patient mismatch cases. Although the postoperative pressure gradient was higher in the 16-mm group (33.7+/-12.5 vs 23.16+/-8.78, p<0.01), left ventricular mass index and left ventricular ejection fraction at early and at late follow-up improved from the preoperative period in both groups. We found no significant differences in incidence of postoperative complications, including death.

CONCLUSIONS

We believe aortic valve replacement with small-diameter mechanical valves (the ATS-AP valves) in patients with a small annulus provides satisfactory remote prognosis. The use of mechanical valves in elderly patients is considered acceptable with strict clinical monitoring to prevent thromboembolism and anticoagulation therapy-induced complications.

Critical review of health-related quality of life studies of patients with aortic stenosis

BACKGROUND

While studies of health-related quality of life (HRQOL) are increasing among cardiovascular patients, very few have examined HRQOL in persons with aortic stenosis (AS).

PURPOSE

A critical review of studies (1997-2008) of HRQOL in persons with AS was conducted to summarize findings and identify clinical and research implications.

RESULTS

Twenty-eight studies were identified, all of which were quantitative and evaluated HRQOL after aortic valve replacement (AVR). No studies conducted by nurses or studies measuring HRQOL in persons who did not undergo AVR were found. The literature focused on age and type of valve as variables influencing HRQOL postoperatively. Although results varied, elderly patients often scored similar or better than comparison groups. Health-related quality of life was found to be affected by valve noise and anticoagulation rather than the specific valve type when comparing patients receiving biological versus mechanical valves.

CONCLUSIONS

Selection for surgery should not be based on age alone. Early consideration should be given to symptoms prior to surgery because of evidence that patients with fewer symptoms preoperatively have better HRQOL after AVR. Anticoagulation status should be evaluated as an independent variable of HRQOL in future studies.

IMPLICATIONS FOR RESEARCH AND PRACTICE

Researchers need to augment generic HRQOL measures with disease-specific items that may pertain to life areas affected by AS, such as audible valve click, wound healing, and dyspnea. Future research should be inclusive of AS patients who do not undergo surgery. Nurses in a variety of roles can work independently or within a multidisciplinary team to provide interventions for the promotion of HRQOL for patients across all stages of the AS disease process.

Up to twenty-five-year survival after aortic valve replacement with size 19 mm valves

Long-term survival was investigated in 202 patients who underwent isolated aortic valve replacement (AVR) with 19 mm valves. There were 171 women with a mean age of 69+/-9 years and 31 men with a mean age of 64+/-13 years. Patients had a mean body surface area of 1.61+/-0.13 m(2). Patient-prosthesis mismatch was moderate in 196 and severe in six patients. The mean follow-up for all patients was 78 months. There were 79 late deaths. The actuarial survival rates for all patients were 95+/-1% at 1 year, 75+/-2% at 5 years, 56+/-2% at 10 years, 41+/-2% at 15 years, 34+/-3% at 20 years and 34+/-2% at 25 years. Patients over 70 years old had a lower survival rate (P=0.0001). There were significant differences between ejection fraction (EF) >55% and EF <55% (P=0.0305). AVR with 19 mm valves appeared to provide satisfactory mid-term survival. Age and low EF were risk factors for shorter survival.

Health-related quality of life after cardiac surgery

Health-related quality of life (HRQOL) assessments are designed to reflect a patient's perspective of how a disease has affected their overall health status. Patient-centered outcomes are of value both for risk assessment and as an outcome measure. Strategies for analyzing HRQOL data are inconsistent primarily because the data frequently do not meet underlying assumptions of traditional methods for statistical analyses and require a careful analytic approach.

Echocardiographic Follow-Up after Implanting 17-mm Regent Mechanical Prostheses

The aim of this study was to evaluate midterm echocardiographic results and changes in quality of life after aortic valve replacement with 17-mm St. Jude Medical Regent mechanical prostheses in patients with aortic valve stenosis. The study population was 34 women and 2 men, aged 31–83 years. Echocardiographic follow-up was 100% complete at 4.1 ± 1.8 years. Hospital mortality was 5.6%. Actuarial 5-year survival was 88.5% ± 0.067%. Postoperative echocardiography showed significant regression of left ventricular mass index and significant reductions of peak gradient, mean gradient and mean effective orifice area index. All survivors were interviewed using the 36-item Short Form Health Survey questionnaire. Scores obtained in 7 of the 8 domains of the test were significantly higher than preoperative values. In our experience, implantation of this prosthesis allowed regression of left ventricular mass index and improved the perceived quality of life.

Effect of surgeon on transprosthetic gradients after aortic valve replacement with Freestyle stentless bioprosthesis and its consequences: a follow-up study in 587 patients

Background

The implantation of stentless valves is technically demanding and the outcome may depend on the performance of surgeons. We studied systematically the role of surgeons and other possible determinants for mid-term survival, postoperative gradients and Quality of Life (QoL) after aortic valve replacement (AVR) with Freestyle^® stentless bioprostheses.

Methods

Between 1996 and 2003, 587 patients (mean 75 years) underwent AVR with stentless Medtronic Freestyle^® bioprostheses. Follow-up was 99% complete. Determinants of morbidity, mortality, survival time and QoL were evaluated by multiple, time-related, regression analysis. Risk models were built for all sections of the Nottingham Health Profile (NHP): energy, pain, emotional reaction, sleep, social isolation and physical mobility

Results

Actuarial freedom from aortic valve re-operation, structural valve deterioration, non-structural valve dysfunction, prosthetic valve endocarditis and thromboembolic events at 6 years were 95.9 ± 2.1%, 100%, 98.7 ± 0.5%, 97.0 ± 1.5%, 79.6 ± 4.3%, respectively. The actuarial freedom from bleeding events at 6 years was 93.1 ± 1.9%. Estimated survival at 6 years was similar to the age-matched German population (61.4 ± 3.8 %). Predictors of survival time were: diabetes mellitus, atrial fibrillation, peripheral vascular disease, renal dysfunction, female gender > 80 years and patients < 165 cm with BMI < 24. Predictive models showed characteristic profiles and good discriminative powers (c-indexes > 0.7) for each of the 6 QoL sections. Early transvalvular gradients were identified as independent risk factors for impaired physical mobility (c-index 0.77, p < 0.002). A saturated propensity score identified besides patient related factors (e.g. preoperative gradients, ejection fraction, haematological factors) indexed geometric orifice area, subcoronary implantation technique and individual surgeons as predictors of high gradients.

Conclusion

In addition to the valve size (in relation to body size), subcoronary technique (versus total root) and various patient-related factors the risk of elevated gradients after stentless valve implantation depends, considerably on the individual surgeon.

Although there was no effect on survival time and most aspects of QoL, higher postoperative transvalvular gradients affect physical mobility after AVR.

Aortic root enlargement: what are the operative risks?

OBJECTIVE

Despite concern that small aortic valve prostheses can lead to prosthesis-patient mismatch with diminished left ventricular mass regression and poor long-term outcome after aortic valve replacement, there remains reluctance to perform aortic root enlargement procedures. We therefore examined the operative risks of aortic valve replacement with and without root enlargement.

METHODS

We reviewed perioperative outcomes among patients undergoing aortic valve replacement at our institution between January 1993 and December 2001. Risk factors for operative death were evaluated by means of multivariable analysis.

RESULTS

Of 2366 patients undergoing aortic valve replacement with (1173) or without (1193) concomitant procedures, 249 (10.5%) underwent posterior root enlargement. Patients undergoing complex root enlargement (Konno-Rastan procedures) were excluded. Patients undergoing aortic root enlargement were significantly younger, twice as often female, and more often undergoing a reoperation but were similar with respect to functional class. The mean valve implant size was less in the aortic root enlargement group (21.5 +/- 1.6 vs 23.2 +/- 2.3 mm, P < .0001). As expected, mean crossclamp time and bypass time were somewhat longer with root enlargement. Raw operative mortality was higher with aortic root enlargement (5.6% vs 2.9%, P = .0324); however, by means of multivariable analysis, advanced functional class (P = .0020; odds ratio, 1.87), preoperative congestive heart failure (P < .0001; odds ratio, 3.22), and smaller valve implant size (P = .012; odds ratio, 1.16), but not aortic root enlargement, were independent risk factors for operative death.

CONCLUSIONS

Aortic root enlargement itself does not increase operative risk, although it is most often required among high-risk patients. Surgeons should not be reluctant to enlarge the aortic root to permit implantation of adequately sized valve prostheses.

Aortic Annular Enlargement During Aortic Valve Replacement: Improving Results With Time

BACKGROUND

Enlargement of the aortic annulus during aortic valve replacement permits insertion of a larger prosthetic valve. Previous reports suggest patch enlargement of the aortic annulus increases operative morbidity and mortality during aortic valve replacement. We compared outcomes for this procedure in a contemporary group of patients with those operated on during an earlier era, to determine whether aortic annular enlargement is still associated with worse outcomes.

METHODS

We reviewed prospectively gathered data on all patients undergoing aortic valve replacement and aortic annular enlargement at our institution from 1995 to 2005 (n = 669). We compared patient outcomes from two consecutive time periods: 1995 through 2000 (n = 360) versus 2001 through 2005 (n = 309). Propensity matching adjusted for baseline differences in a secondary analysis.

RESULTS

Operative mortality was significantly lower in the more recent surgical group (2.9% versus 7.2%; p = 0.013). The rates of perioperative myocardial infarction (1.9% versus 1.1%; p = 0.4), stroke (2.9% versus 3.3%; p = 0.8), and pacemaker implantation (9.1% versus 12.5%; p = 0.16) were similar for both groups (2001 through 2005 versus 1995 through 2000, respectively). The earlier group of patients had a higher prevalence of congestive heart failure, syncope, angina, New York Heart Association class III or IV symptoms, chronic obstructive pulmonary disease, mitral valve disease, and previous cardiac surgery. After adjusting for these baseline differences with propensity matching, the risk of perioperative death remained lower in the contemporary group (3% versus 7.5%; p = 0.04).

CONCLUSIONS

Enlargement of the aortic annulus in the modern era is a safe adjunct to aortic valve replacement, and should be considered in selected patients to avoid patient-prosthesis mismatch.