Valve Prosthesis-patient Mismatch Research Articles

Long-term survival after Carpentier-Edwards Perimount aortic valve replacement in Western Denmark: a multi-centre observational study

BackgroundThis study describes the long-term survival, risk of reoperation and clinical outcomes of patients undergoing solitary surgical aortic valve replacement (SAVR) with a Carpentier-Edwards Perimount (CE-P) bioprosthetic in Western Denmark. The renewed interest in SAVR is based on the questioning regarding the long-term survival since new aortic replacement technique such as transcatheter aortic-valve replacement (TAVR) probably have shorter durability, why assessment of long-term survival could be a key issue for patients.MethodsFrom November 1999 to November 2013 a cohort of a total of 1604 patients with a median age of 73 years (IQR: 69–78) undergoing solitary SAVR with CE-P in Western Denmark was obtained November 2018 from the Western Danish Heart Registry (WDHR). The primary endpoint was long-term survival from all-cause mortality. Secondary endpoints were survival free from major adverse cardiovascular and cerebral events (MACCE), risk of reoperation, cause of late death, patient-prothesis mismatch, risk of AMI, stroke, pacemaker or ICD implantation and postoperative atrial fibrillation (POAF). Time-to-event analysis was performed with Kaplan-Meier curve, cumulative incidence function was performed with Nelson-Aalen cumulative hazard estimates. Cox regression was applied to detect risk factors for death and reoperation.ResultsIn-hospital mortality was 2.7% and 30-day mortality at 3.4%. The 5-, 10- and 15-year survival from all-cause mortality was 77, 52 and 24%, respectively. Survival without MACCE was 80% after 10 years. Significant risk factors of mortality were small valves, smoking and EuroSCORE II ≥4%. The risk of reoperation was < 5% after 7.5 years and significant risk factors were valve prosthesis-patient mismatch and EuroSCORE II ≥4%.ConclusionsPatients undergoing aortic valve replacement with a Carpentier-Edwards Perimount valve shows a very satisfying long-term survival. Future research should aim to investigate biological valves long-term durability for comparison of different SAVR to different TAVR in long perspective.

Managing the Small Aortic Annulus: Which Valve Type Offers Superior Haemodynamic Performance in the Current Era?

Objective: The presence of a small aortic annulus (SAA) poses a clinical challenge in patients with aortic stenosis (AS). SAA has been associated with poorer outcomes after aortic valve replacement (AVR), with increased risk of suboptimal valve haemodynamics, prosthesis-patient mismatch (PPM), mortality and cardiovascular events. Recent TAVI trials have demonstrated superior haemodynamic performance compared to conventional SAVR valves. Methods: A retrospective review of the hemodynamic performance as assessed by echocardiography of size 19 Edward’s Intuity rapid deployment (RVD) and CE Perimount Magna Ease (SAVR) surgical aortic valves implanted by a single surgeon was performed. The performance of small sized trans-catheter aortic valves (TAVR) (Edwards Sapien 3 Size 20, Medtronic CoreValve size 23) was also analysed. Results: Edwards Intuity size 19 showed statistically superior haemodynamic performance than equivalent sized SAVR (p<0.02; mean 10.6 vs 19.7 mmHg; peak 20 vs 37mmHg). RDV showed equivalent haemodynamic to TAVR valves (mean 10.6 vs 19.8 {Sapien p=0.11} vs 11 {CoreValve p=0.7}; peak 20 vs 36 {Sapien p=0.08} vs 20 {CoreValve p=0.9}). RDV significantly reduces cardiopulmonary bypass (CPB) and aortic X-clamp times compared to conventional SAVR (p=0.001). Conclusions: Among patients with SAA undergoing surgical AVR, Edward’s Intuity Size 19 offers superior haemodynamic performance with the added benefit of reduced CPB and X-clamp times.

Prosthesis-patient mismatch after mitral valve replacement: A pooled meta-analysis of Kaplan-Meier-derived individual patient data.

ObjectiveThe hemodynamic effect and early and late survival impact of prosthesis–patient mismatch (PPM) after mitral valve replacement remains insufficiently explored.MethodsPubmed, Embase, Web of Science, and Cochrane Library databases were searched for English language original publications. The search yielded 791 potentially relevant studies. The final review and analysis included 19 studies compromising 11,675 patients.ResultsProsthetic effective orifice area was calculated with the continuity equation method in 7 (37%), pressure half‐time method in 2 (10%), and partially or fully obtained from referenced values in 10 (53%) studies. Risk factors for PPM included gender (male), diabetes mellitus, chronic renal disease, and the use of bioprostheses. When pooling unadjusted data, PPM was associated with higher perioperative (odds ratio [OR]: 1.66; 95% confidence interval [CI]: 1.32–2.10; p < .001) and late mortality (hazard ratio [HR]: 1.46; 95% CI: 1.21–1.77; p < .001). Moreover, PPM was associated with higher late mortality when Cox proportional‐hazards regression (HR: 1.97; 95% CI: 1.57–2.47; p < .001) and propensity score (HR: 1.99; 95% CI: 1.34–2.95; p < .001) adjusted data were pooled. Contrarily, moderate (HR: 1.01; 95% CI: 0.84–1.22; p = .88) or severe (HR: 1.19; 95% CI: 0.89–1.58; p = .24) PPM were not related to higher late mortality when adjusted data were pooled individually. PPM was associated with higher systolic pulmonary pressures (mean difference: 7.88 mmHg; 95% CI: 4.72–11.05; p < .001) and less pulmonary hypertension regression (OR: 5.78; 95% CI: 3.33–10.05; p < .001) late after surgery.ConclusionsMitral valve PPM is associated with higher postoperative pulmonary artery pressure and might impair perioperative and overall survival. The relation should be further assessed in properly designed studies.

Benchmarking Outcomes: Reoperation for Aortic Valve Patient-Prosthesis Mismatch

Surgical reoperations for symptomatic aortic valve patient-prosthesis mismatch (PPM) are complex. The purpose of this research was to investigate the clinical and echocardiographic outcomes of patients who underwent reoperation for correction of symptomatic PPM after prior aortic valve replacement. An institutional review identified 60 patients from 2004 to 2018 who underwent reoperative aortic valve replacement for PPM without structural valve degeneration. Univariate analyses were conducted to evaluate risk factors for perioperative mortality. Median patient age was 62.8 (interquartile range, 48.3-68.7) years, and mean body mass index was 29.2 ± 6.6 kg/m2. Thirty-nine (66%) patients underwent a first-time reoperation, and 18 (30.5%) underwent a second-time reoperation. The median interval between initial operation to reoperation for the treatment of PPM was 89 months. Thirty-four (56.7%) patients underwent aortic root replacement, while the remainder (43.3%) underwent aortic valve replacement. Additional procedures included replacement of the ascending aorta with or without aortic arch in 26 (43.3%) patients and coronary artery bypass grafting in 7 (12%) patients. Operative mortality and the rates of stroke and renal failure were 5.0%, 3.3%, and 5.0%, respectively. Echocardiographic follow-up was available in 64.9% of patients at a mean follow-up of 36.5 months. Preoperative mean pressure gradients were 32.1 ± 16.0 mm Hg and mean aortic valve area was 0.8 ± 0.3 cm2, and both improved to 6.6 ± 4.2 mm Hg and 2.3 ± 0.7 cm2 (P < .001). Reoperative surgery for PPM is complex but may be performed with good outcomes and low mortality in experienced centers. These data provide excellent clinical and hemodynamic benchmarks for the treatment of PPM in the current era of valve-in-valve transcatheter aortic valve replacement.

Durability and Clinical Outcomes of Transcatheter Aortic Valve Replacement for Failed Surgical Bioprostheses.

Valve-in-valve transcatheter aortic valve replacement (TAVR) is an option when a surgical valve demonstrates deterioration and dysfunction. This study reports 3-year results following valve-in-valve with self-expanding TAVR. The CoreValve US Expanded Use Study is a prospective, nonrandomized, single-arm study that evaluates safety and effectiveness of TAVR in extreme risk patients with symptomatic failed surgical biologic aortic valves. Study end points include all-cause mortality, need for valve reintervention, hemodynamic changes over time, and quality of life through 3 years. Patients were stratified by presence of preexisting surgical valve prosthesis-patient mismatch. From March 2013 to May 2015, 226 patients deemed extreme risk (STS-PROM [Society of Thoracic Surgeons Predicted Risk of Mortality] 9.0±7%) had attempted valve-in-valve TAVR. Preexisting surgical valve prosthesis-patient mismatch was present in 47.2% of the cohort. At 3 years, all-cause mortality or major stroke was 28.6%, and 93% of patients were in New York Heart Association I or II heart failure. Valve performance was maintained over 3 years with low valve reintervention rates (4.4%), an improvement in effective orifice area over time and a 2.7% rate of severe structural valve deterioration. Preexisting severe prosthesis-patient mismatch was not associated with 3-year mortality but was associated with significantly less improvement in quality of life at 3-year follow-up (P=0.01). Self-expanding TAVR in patients with failed surgical bioprostheses at extreme risk for surgery was associated with durable hemodynamics and excellent clinical outcomes. Preexisting surgical valve prosthesis-patient mismatch was not associated with mortality but did limit patient improvement in quality of life over 3-year follow-up. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01675440.

Effect of prosthesis patient mismatch in mitral position on pulmonary hypertension.

Pulmonary arterial hypertension (PAH) is associated with poor outcome after mitral valve replacement (MVR). We proposed to evaluate the effect of valve prosthesis patient mismatch (PPM) on pulmonary arterial (PA) pressure following MVR. Five hundred patients who have undergone MVR were studied retrospectively. Postoperative PA systolic pressure (PASP) measured 6 months postoperatively by Doppler echocardiography was compared with preoperative values. PASP ≥ 40 mmHg was defined as PAH. Mitral valve effective orifice area was calculated by the continuity equation and indexed for body surface area. PPM was defined as indexed effective orifice area ≤ 1.2 cm2/m2. A multivariate model was constructed to ascertain the independent determinants of systolic PA pressure. Also, a propensity score model was constructed to overcome the baseline differences between the PPM and no PPM groups. The incidence of PPM in this study was 37.2%. The average postoperative PASPs were 30.49 and 42.35 mmHg in the no PPM and PPM groups, respectively; (P < 0.001). Regression of PAH in the PPM and no PPM groups was 76.26% and 20.64%, respectively; (P < 0.001). The indexed effective orifice area correlated well with postoperative PASP (r = 0.71). The overall survival and freedom from cardiac death at 10 years were 79.8% and 85.3%; and at 20 years were 66.5% and 74.3%, respectively. Both, overall survival and the freedom from cardiac death were higher in the no PPM group than in the PPM group; (P < 0.001). Propensity score matching analysis yielded 112 pairs of the PPM and no PPM cohorts, which revealed higher overall survival and freedom from cardiac death in the no PPM group; (P = 0.028 and 0.012, respectively). Mitral PPM is an independent predictor of persistent PAH after MVR along with associated morbidity and reduced survival.

1-Year Results in Patients Undergoing Transcatheter Aortic Valve Replacement With Failed Surgical Bioprostheses

ObjectivesThis study evaluated the safety and effectiveness of self-expanding transcatheter aortic valve replacement (TAVR) in patients with surgical valve failure (SVF). BackgroundSelf-expanding TAVR is superior to medical therapy for patients with severe native aortic valve stenosis at increased surgical risk. MethodsThe CoreValve U.S. Expanded Use Study was a prospective, nonrandomized study that enrolled 233 patients with symptomatic SVF who were deemed unsuitable for reoperation. Patients were treated with self-expanding TAVR and evaluated for 30-day and 1-year outcomes after the procedure. An independent core laboratory was used to evaluate serial echocardiograms for valve hemodynamics and aortic regurgitation. ResultsSVF occurred through stenosis (56.4%), regurgitation (22.0%), or a combination (21.6%). A total of 227 patients underwent attempted TAVR and successful TAVR was achieved in 225 (99.1%) patients. Patients were elderly (76.7 ± 10.8 years), had a Society of Thoracic Surgeons Predicted Risk of Mortality score of 9.0 ± 6.7%, and were severely symptomatic (86.8% New York Heart Association functional class III or IV). The all-cause mortality rate was 2.2% at 30 days and 14.6% at 1 year; major stroke rate was 0.4% at 30 days and 1.8% at 1 year. Moderate aortic regurgitation occurred in 3.5% of patients at 30 days and 7.4% of patients at 1 year, with no severe aortic regurgitation. The rate of new permanent pacemaker implantation was 8.1% at 30 days and 11.0% at 1 year. The mean valve gradient was 17.0 ± 8.8 mm Hg at 30 days and 16.6 ± 8.9 mm Hg at 1 year. Factors significantly associated with higher discharge mean aortic gradients were surgical valve size, stenosis as modality of SVF, and presence of surgical valve prosthesis patient mismatch (all p < 0.001). ConclusionsSelf-expanding TAVR in patients with SVF at increased risk for surgery was associated with a low 1-year mortality and major stroke rate, significantly improved aortic valve hemodynamics, and low rates of moderate and no severe residual aortic regurgitation, with improved quality of life.

Aortic valve prosthesis–patient mismatch and exercise capacity in adult patients with congenital heart disease

ObjectivesTo report the prevalence of aortic valve prosthesis–patient mismatch (PPM) in an adult population with congenital heart disease (CHD) and its impact on exercise capacity. Adults with congenital heart disease...

Invited Commentary

Invited Commentary

Prediction of Acute Kidney Injury Within 30 Days of Cardiac Surgery

Introduction: It is unclear whethermanufacturer provided charts actually predict the probability of aortic valve patientprosthesis mismatch (PPM). The aim of the study was to determine whether these charts reliably predict PPM in patients undergoing aortic valve replacement (AVR). Methods: We undertook a retrospective analysis of echocardiographic data from Geelong Hospital with institutional ethics approval. Between January 2006 and December 2010, 405 patients in our hospital underwent AVR with either a mechanical prosthesis or a stented bioprosthesis. 152 patients had adequate echocardiographic follow up (mean time to follow up 104 days). The measured gradient and effective orifice area index (EOAI) were compared to the values provided by the manufacturer. Results: Despite no patient having preoperatively predicted severe PPM according to manufacturer charts, 62 patients (40.8%) had postoperative echocardiographic evidence of severe PPM. The accuracy of the charts to predict severe PPM was 59.2%. The rate of postoperatively measured moderate or greater PPM was 77.6%. Sensitivity and specificity of manufacturer charts for moderate or greater PPM were 27.1% (19.5–36.2%) and 88.2% (71.6–96.1%) respectively. The accuracy of the charts for moderate or greater PPM was 41.4%. Postoperatively measured average EOA across all valve types and sizes were lower than those provided by the manufacturer. Postoperative aortic valvemean pressure gradient in patients with severe PPM was 18.5 6.3 mmHg, moderate PPM 13.7 4.3 mmHg and no PPM 12.6 3.2 mmHg. Discussion: The accuracy of industry provided charts for EOAI calculation is poor. We conclude that these charts are not useful in the pre-operative prediction of severe PPM in patients undergoing AVR.

Deep Sternal Wound Infection Following Cardiac Surgery: Risk and Outcomes

Introduction: It is unclear whethermanufacturer provided charts actually predict the probability of aortic valve patientprosthesis mismatch (PPM). The aim of the study was to determine whether these charts reliably predict PPM in patients undergoing aortic valve replacement (AVR). Methods: We undertook a retrospective analysis of echocardiographic data from Geelong Hospital with institutional ethics approval. Between January 2006 and December 2010, 405 patients in our hospital underwent AVR with either a mechanical prosthesis or a stented bioprosthesis. 152 patients had adequate echocardiographic follow up (mean time to follow up 104 days). The measured gradient and effective orifice area index (EOAI) were compared to the values provided by the manufacturer. Results: Despite no patient having preoperatively predicted severe PPM according to manufacturer charts, 62 patients (40.8%) had postoperative echocardiographic evidence of severe PPM. The accuracy of the charts to predict severe PPM was 59.2%. The rate of postoperatively measured moderate or greater PPM was 77.6%. Sensitivity and specificity of manufacturer charts for moderate or greater PPM were 27.1% (19.5–36.2%) and 88.2% (71.6–96.1%) respectively. The accuracy of the charts for moderate or greater PPM was 41.4%. Postoperatively measured average EOA across all valve types and sizes were lower than those provided by the manufacturer. Postoperative aortic valvemean pressure gradient in patients with severe PPM was 18.5 6.3 mmHg, moderate PPM 13.7 4.3 mmHg and no PPM 12.6 3.2 mmHg. Discussion: The accuracy of industry provided charts for EOAI calculation is poor. We conclude that these charts are not useful in the pre-operative prediction of severe PPM in patients undergoing AVR.

The medtronic melody® transcatheter pulmonary valve implanted at 24‐mm diameter—it works

We report the Melody valve implanted and/or expanded to 24-mm diameter. The Medtronic Melody valve has been implanted up to 22 mm in the pulmonary position for over a decade. A retrospective chart review was performed on 82 patients who underwent Melody valve implant. Technical implant method, pre- and postimplant echocardiographic findings, and initial follow-up were reviewed. Between 04/2008 and 12/2011, 13 Melody valves were successfully implanted in 11 patients, median age 35 years (range 16-61 years), in the pulmonary (bioprosthetic valve, right ventricle to pulmonary artery conduit, native valve) position (n = 9), tricuspid position (bioprosthetic valve n = 3), and aortic position (bioprosthetic valve n = 1). Ten valves were delivered on a 24-mm balloon in balloon catheter and three were implanted using a 22-mm Ensemble balloon delivery system, followed by postdilation using a 24-mm × 2-cm Atlas balloon catheter. Postimplant, the median peak systolic gradient across the pulmonary valve was 7 mm Hg and median gradient across the tricuspid valve was 3 mm Hg. There was no change in gradient across the Melody valve in the aortic position where valve prosthesis-patient mismatch was present. Postimplant intracardiac echocardiography demonstrated none or mild valve regurgitation. No more than mild regurgitation was noted at a median follow-up of 9.5 months. The Melody valve can be implanted at 24 mm in the stenotic/regurgitant bioprosthetic pulmonary, tricuspid, and aortic valve, dysfunctional right ventricle to pulmonary artery conduit, and the native right ventricular outflow tract, whereas the valve remains competent with only mild regurgitation.

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 (<1.6m(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.

Current approach for the prosthesis patient mismatch

All prosthetic valves are at least mildly stenotic and have relatively high transvalvular pressure gradients that can be observed despite normal prosthesis function. Such gradients may be due to a mismatch between prosthesis effective orifice area (EOA) and patient's body size. Valve prosthesis-patient mismatch (VP-PM) may occur due to mismatches of both parameters, the expected hemodynamic performance of the prosthesis and the cardiac output requirements of the patient, which are largely related to the body size at rest. In other words, a prosthesis may be adequate for patients with a small body surface area (BSA) but might become obstructive for patients with a large BSA. The only parameter that has proven to be consistently and realistically useful to predict and describe VP-PM is the effective orifice area index (EOAI). The projected EOAI was identified as the best parameter to predict the VP-PM occurrence after surgery. VP-PM has been known to be independently and significantly associated with clinical outcomes. Severe VP-PM has a significant impact on early and late mortality, whereas moderate VP-PM may have a significant effect on mortality only in vulnerable subsets of patients, and particularly in those with depressed LV systolic function. The surgeon's anticipation of VP-PM prior to surgery, and successfully implented preventive strategies can reduce the incidence of VP-PM. Preventive strategies to avoid VP-PM should be individualized according to the anticipated severity of VP-PM and of the patient's baseline risk profile.

Still searching for the elusive Scarlet Pimpernel of today

This editorial refers to ‘The impact of prosthesis–patient mismatch on long-term survival after aortic valve replacement: a systematic review and meta-analysis of 34 observational studies comprising 27 186 patients with 133 141 patient-years†, by S.T. Head et al. , on page 1518 Since the first description of valve prosthesis–patient mismatch (VP-PM) in 1978,1 the problem has been addressed in a large number of studies that have evaluated its effect on patient outcomes. Data regarding the reduction of long-term survival in those with VP-PM have been conflicting. To resolve this conflict, using pooled estimates, Head et al. have provided a systematic review of 34 selected studies assessing the impact of VP-PM after aortic valve replacement (AVR).2 In these 34 studies, 44.2% of the patients had severe or moderate VP-PM which was associated with an increased incidence of all-cause mortality that was statistically significant; however, the incidence of VP-PM associated with cardiac-related mortality was not statistically significant. In seven of these 34 studies, when both moderate and severe VP-PM were analysed …

Accuracy of Industry Generated Effective Orifice Area Calculators for Aortic Valve Replacement

Introduction: It is unclear whethermanufacturer provided charts actually predict the probability of aortic valve patientprosthesis mismatch (PPM). The aim of the study was to determine whether these charts reliably predict PPM in patients undergoing aortic valve replacement (AVR). Methods: We undertook a retrospective analysis of echocardiographic data from Geelong Hospital with institutional ethics approval. Between January 2006 and December 2010, 405 patients in our hospital underwent AVR with either a mechanical prosthesis or a stented bioprosthesis. 152 patients had adequate echocardiographic follow up (mean time to follow up 104 days). The measured gradient and effective orifice area index (EOAI) were compared to the values provided by the manufacturer. Results: Despite no patient having preoperatively predicted severe PPM according to manufacturer charts, 62 patients (40.8%) had postoperative echocardiographic evidence of severe PPM. The accuracy of the charts to predict severe PPM was 59.2%. The rate of postoperatively measured moderate or greater PPM was 77.6%. Sensitivity and specificity of manufacturer charts for moderate or greater PPM were 27.1% (19.5–36.2%) and 88.2% (71.6–96.1%) respectively. The accuracy of the charts for moderate or greater PPM was 41.4%. Postoperatively measured average EOA across all valve types and sizes were lower than those provided by the manufacturer. Postoperative aortic valvemean pressure gradient in patients with severe PPM was 18.5 6.3 mmHg, moderate PPM 13.7 4.3 mmHg and no PPM 12.6 3.2 mmHg. Discussion: The accuracy of industry provided charts for EOAI calculation is poor. We conclude that these charts are not useful in the pre-operative prediction of severe PPM in patients undergoing AVR.

Hemodynamic Factors Affecting the Fate of Valvular Bioprosthesis

Ce qui est simple est faux mais ce qui ne l’est pas est inutilisable. — —Paul Valery Since their introduction in 1969, valvular bioprostheses (ie, glutaraldehyde-processed animal valves)1 have experienced a surprising increase in use as a result of progress in valve processing2 and growing patient desire for nonthrombogenic valve surgery.3 However, the persistent risk of structural valve deterioration, particularly in the young population, remains a major concern. The 2 main causes of valve failure are valve degeneration and calcification. Among the numerous factors influencing the fate of a bioprosthesis, hemodynamic factors are addressed more rarely than biological factors. In this issue of Circulation , Flameng and colleagues4 add important information to the understanding of how hemodynamic factors play a role in structural valve failure. To do so, they revive an old debate on the practical significance of prosthesis-patient mismatch. First introduced by Rahimtoola in 19785 and having fed numerous discussions for many years, this paradigm led to the simple conclusion that, in aortic valve replacement, the larger the valve is, the better the hemodynamics and therefore the clinical result are. Accordingly, surgeons were advised to carefully measure the aortic valve orifice and to select a valve by fitting the aortic valve orifice in correlation …

Prosthesis–patient mismatch: myth or reality?

Valve replacement for severe calcified aortic stenosis (AS) is currently the second most frequently performed cardiac operation. In these patients, the insertion of a small size prosthesis is an issue...

Impact of Prosthesis-Patient Mismatch on Long-Term Survival After Aortic Valve Replacement: Influence of Age, Obesity, and Left Ventricular Dysfunction

This study was designed to evaluate the effect of valve prosthesis-patient mismatch (PPM) on late survival after aortic valve replacement (AVR) and to determine if this effect is modulated by patient age, body mass index (BMI), and pre-operative left ventricular (LV) function. We recently reported that PPM is an independent predictor of operative mortality after AVR, particularly when associated with LV dysfunction. The indexed valve effective orifice area (EOA) was estimated in 2,576 patients having survived AVR and was used to define PPM as not clinically significant if it was >0.85 cm(2)/m(2), as moderate if >0.65 and < or =0.85 cm(2)/m(2), and severe if < or =0.65 cm(2)/m(2). After adjustment for other risk factors, severe PPM was associated with increased late overall mortality (hazard ratio [HR]: 1.38; p = 0.03) and cardiovascular mortality (HR: 1.63; p = 0.0006) in the whole cohort. Severe PPM was also associated with increased overall mortality in patients <70 years old (HR: 1.77; p = 0.002) and in patients with a BMI <30 kg/m(2) (HR: 2.1; p = 0.006), but had no impact in older patients or in obese patients. Moderate PPM was a predictor of mortality in patients with LV ejection fraction <50% (HR: 1.21; p = 0.01), but not in patients with preserved LV function. Moderate PPM is associated with increased late mortality in patients with LV dysfunction, but with normal prognosis in those with preserved LV function. Notwithstanding the previously demonstrated deleterious effect of severe PPM on early mortality, this factor appears to increase late mortality only in patients <70 years old and/or with a BMI <30 kg/m(2) or an LV ejection fraction <50%.

Impact of valve prosthesis-patient mismatch estimated by echocardiographic-determined effective orifice area on long-term outcome after aortic valve replacement

The impact of valve prosthesis-patient mismatch on long-term outcome after aortic valve replacement estimated by various variables such as projected indexed effective orifice area and internal geometric orifice area obtained from in vivo or in vitro published data is still controversial. The effective orifice area was measured by echocardiography in 533 patients. The mean age of the patients was 71 +/- 9 years; mean follow-up time was 4.7 +/- 2.2 years. The impact of severe (indexed effective orifice area <or=0.6 cm(2)/m(2)) and moderate mismatch (0.6 cm(2)/m(2) < indexed effective orifice area <or=0.85 cm(2)/m(2)) on survival was evaluated by Cox regression. Severe mismatch (hazard ratio: 1.9 [1.08-3.21]) was a significant predictor of survival time after adjustment for age, left ventricular ejection fraction, atrial fibrillation, New York Heart Association class, serum creatinine, and hemoglobin level. The 5- and 7-year survival rates were 71% +/- 4% and 54% +/- 8% for patients with severe mismatch and 83% +/- 4% and 80% +/- 8% for patients with mild mismatch, respectively. The correlation between projected and measured indexed effective orifice area was of medium strength (r = 0.49), and the frequency of observed mismatch depended linearly on the projected indexed effective orifice area. Although projected indexed effective orifice area and indexed internal geometric orifice area were significant predictors of severe mismatch, the sensitivity and specificity for severe prosthesis-patient mismatch were only 75% and 52%, using an optimal threshold of projected indexed effective orifice area defined by the Youden index. Severe prosthesis-patient mismatch estimated by effective orifice area measured within 10 days was an independent risk factor of survival time. Projected indexed effective orifice area determined at surgery does not sufficiently predict mismatch.