Mechanical AVR Research Articles

Cardiac valve surgery in Far North Queensland, Australia. A retrospective audit of rheumatic heart disease prevalence, patient demographics and surgical management

Abstract Funding Acknowledgements Type of funding sources: None. Background Rheumatic heart disease (RHD) is a preventable valve disease following acute rheumatic fever. It results in >300,000 deaths annually worldwide (1). While commonly encountered in the developing world, the prevalence in Australia remains high with over 6000 patients currently living with RHD (2). This disease is over-represented in Northern Australia among the indigenous community with Aboriginal and Torres-strait Islander people accounting for over 80% of cases (2). Purpose This audit will evaluate the contribution of RHD to valve surgeries in Far North Queensland (FNQ) and the effect this has on procedure type and patient demographics. Methods We analysed a cohort of 200 consecutive patients from a regional centre in FNQ referred for valve surgery. We recorded age, gender, indigenous status, valve aetiology, ejection fraction (EF), surgery type, and procedure urgency. This data was then compared to the latest European Association for Cardio-Thoracic Surgery (EACTS) registry report (3). Results 136 male and 64 female patients underwent 162 elective and 38 emergent valve procedures. The surgeries performed were bioprosthetic AVR (119), mechanical AVR (12), bioprosthetic MVR (14), mechanical MVR (11), TAVR (17), mitral valve repair (25), tricuspid valve repair (6) and balloon valvuloplasty (5) with combined CABG (33) and aortic root surgery (20). Average age at surgery was 64.2 years (range 21 – 89) which is significantly younger than the EACTS age at aortic, mitral and combined valve/CABG procedures. Notably, the average age at surgery reaches 75 years in European countries with a gross national income of $70,000 per capita. However, this is not evident in FNQ. 27 of the 200 procedures were for RHD and the average age of these patients was 45.4 years which explains this discrepancy. Indigenous patients accounted for 16.5% of total, and 77.8% of rheumatic valve surgeries. Mechanical prostheses comprised 15% and 48% of total and rheumatic valve replacements respectively which contrasts with 30-40% in the EACTS registry. RHD also accounted for almost the entirety of tricuspid valve surgeries and balloon valvuloplasties. The EACTS report suggested higher EF’s in Asian countries due to higher prevalence of RHD. This was not observed in our data with no statistically significant difference in EF between RHD patients and the overall cohort. Unfortunately, there is a lack of valve pathology data in the EACTS registry which limits further comparisons. Conclusion RHD is responsible for a significant proportion of valve surgery in FNQ. The indigenous population accounts for a vast majority of these patients. This has caused a shift towards lower age at surgery, higher proportions of mechanical valve replacements, valvuloplasties and tricuspid valve replacements. EF did not significantly differ in patients with rheumatic valve pathology. More data surrounding valve pathology is needed to draw similar conclusions in the EACTS cohorts.

The effect of cardiac surgery type on incidence of post-operative atrial fibrillation amongst patients with post-procedural conduction disease

Abstract Funding Acknowledgements Type of funding sources: None. Background Approximately 1% of cardiac operations result in post-operative heart block (PoHB). Post -operative atrial fibrillation (PoAF) has been quoted as occurring in 40-50% of combined coronary artery bypass graft (CABG) and valvular procedures, 25% of CABG only and 30% of valve only procedures. The co-existence of PoAF in patients with PoHB, and the link to operation type is less well documented. Purpose To investigate characteristics predisposing patients post cardiac surgery for PoHB and PoAF. Methods We screened patients who had undergone CABG, aortic or mitral valve replacements (AVR and MVR respectively) or mitral valve repairs at Bristol Royal Infirmary between 1/1/2010 and 1/4/2020. We created a merged surgical and electrophysiological database identifying patients with permanent pacemakers inserted within 30 days of cardiac surgery for PoHB to create our final database. By reviewing electronic notes we identified patients in this cohort who developed PoAF prior to discharge. We excluded patients with congenital heart defects or known prior atrial fibrillation. We then analysed the incidence of both PoHB and PoAF for different operation subtypes. Results Of the 10779 operations, 6625 (61%) were CABG-Only, 4124 (38%) were Valve-Only and 1219 (11%) were combined CABG&Valve. In total 85 (0.8%) patients developed PoHB. There was a higher proportion of female patients in the PoHB group but no other demographic differences (See Table 1). In terms of operation type, the PoHB group contained a significantly higher proportion of patients who had undergone AVR (78% vs. 28%, p<0.001). There was also a significant association with operations performed on cardiopulmonary bypass and with longer cross clamp time however this did not remain statistically significant on multivariate analysis. Valve surgery was associated with a higher proportion of patients developing PoHB than CABG, with AVR relating to the highest PoHB rates (AVR 2.0%, MVR 0.9%, CABG 0.2%, p<0.0001). Both mechanical and bioprosthetic AVR were associated with a higher proportion of patients developing PoHB than MVR. In our cohort 34/85 (41%) patients with POHB developed post-operative AF. After univariate analysis of the patient and operation factors listed in Table 1, only age and body mass index were predictors of development of PoAF after multivariate analysis (age: odds ratio 1.81 (1.02-1.36), p=0.024, BMI: odds ratio 1.09 (1.02-1.17), p=0.01), with no association to surgical parameters. Conclusion PoHB occurs commonly following both CABG and valve procedures, with higher incidence in the setting of valve surgery, with our data showing a 2 fold higher chance of PoHB in patients undergoing aortic versus mitral valve replacements. In contrast, there is no clear relationship between type of surgery and development of postoperative atrial fibrillation in this cohort but larger studies are warranted.

Warfarin Compliance after Mechanical AVR in the Pediatric Population: Case Series from a Developing Country

Background and Aim: Mechanical prosthetic heart valves exert a lifelong thromboembolic complication requiring continuous antithrombotic therapy. Vitamin K antagonist is the recommended therapy of choice along with meticulous INR monitoring to achieve and maintain an INR of 2.0 - 3.0. The study aimed to assess the compliance of anticoagulant therapy in pediatric patients after AVR and to highlight the challenges faced during follow-ups. Methods: A retrospective study was conducted at NICVD Hospital in Karachi, Pakistan for a time frame of 2 years from 2020-2021 where 7 patients were selected. Data were collected using hospital medical records and then validated through a phone call mediated structured questionnaire-based interview. Results: 2 out of 7 patients in the case series were compliant to regular follow-ups and had their INR in the desired range owing to their higher education status and access to INR clinic for regular follow-up in urban setting. Younger patients in the case series were non-compliant. 4 out of 7 patients who were on dual anti-coagulant regimens including warfarin and aspirin were either closer or within the range than compared to those on single drug regimen. Conclusion: Compliance was observed in patients who had favorable demographics and higher education. Multiple recent trials including PROACT and PROACT XA are underway to develop novel treatment options apart from warfarin after mechanical aortic valve replacement. Home-based INR testing kits provide easy access to regular testing in remote areas. Multi-center studies are required for in-depth analysis regarding reasons of non-compliance in pediatric population.

Aortic valve replacement in pediatric patients: 30 years single center experience

BackgroundThe choice of aortic valve replacement needs to be decided in an interdisciplinary approach and together with the patients and their families regarding the need for re-operation and risks accompanying anticoagulation. We report long-term outcomes after different AVR options.MethodsA chart review of patients aged < 18 years at time of surgery, who had undergone AVR from May 1985 until April 2020 was conducted. Contraindications for Ross procedure, which is performed since 1991 at the center were reviewed in the observed non-Ross AVR cohort. The study endpoints were compared between the mechanical AVR and the biological AVR cohort.ResultsFrom May 1985 to April 2020 fifty-five patients received sixty AVRs: 33 mechanical AVRs and 27 biological AVRs. In over half of the fifty-three AVRs performed after 1991 (58.5%; 31/53) a contraindication for Ross procedure was present. Early mortality was 5% (3/60). All early deaths occurred in patients aged < 1 year at time of surgery. Two late deaths occurred and survival was 94.5% ± 3.1% at 10 years and 86.4% ± 6.2% at 30 years. Freedom from aortic valve re-operation was higher (p < 0.001) in the mechanical AVR than in the biological AVR cohort with 95.2% ± 4.6% and 33.6% ± 13.4% freedom from re-operation at 10 years respectively.ConclusionsRe-operation was less frequent in the mechanical AVR cohort than in the biological AVR cohort. For mechanical AVR, the risk for thromboembolic and bleeding events was considerable with a composite linearized event rate per valve-year of 3.2%.

Can Moderate Patient Prosthesis Mismatch Be Tolerated in a Selected Group of Patients with Aortic Valve Replacement?

In this study, we aimed to determine the incidence of patient prosthesis mismatch (PPM) and its effects on ejection fraction (EF), gradients, and late survival. 200 patients who underwent isolated mechanical AVR between March 2013 and May 2016 were retrospectively evaluated based on patient records. 200 patients were included in the study. No PPM was detected in 42 (21%) patients, moderate PPM in 122 (61%), and severe PPM in 36 (18%) patients. A significant decrease was found in all groups in terms of mean valve gradients and LVMI (preoperative LVMI compared with postoperative LVMI at the 12th month) (P < .001). A 30% decrease in mean LVMI in the no PPM and moderate PPM groups and a 20% decrease in the severe PPM group were detected at the 6th month. In our postoperative data, we found that EF was preserved, the transvalvular gradient reduced, and LVMI decreased. There was no difference in mortality rates between the control (no PPM) group and the moderate PPM group. Taking into account our patient groups, we can say that no-to-moderate PPM has no major effect on left ventricular remodeling in patients with preserved left ventricular functions.

ACUTE, SEVERE AORTIC REGURGITATION FROM PANNUS OBSTRUCTION: A SHORT WINDOW OF OPPORTUNITY

Acute mechanical AVR obstruction from pannus is an unusual and potentially catastrophic complication. Prompt diagnosis is required for a life-saving procedure. A 69-year old lady with AFib and bicuspid AV stenosis status-post tilting-disc AVR 23 years ago, presented with chest pain, wide pulse-

328 Echocardiographic Features Aiding in Diagnosis of type A Dissection; Forgotten Acoustic Window and Indirect Features

Aortic dissection remains an important differential diagnosis in the patients with chest pain. Typically, echocardiographers focus on visualisation of an intimal flap from a parasternal window when a type A dissection is the suspected diagnosis and in some cases this window does not provide diagnostic features. In these cases, additional acoustics windows which demonstrate secondary features are crucial. For example, a 54-year-old man presented with sudden onset of chest pain, dizziness, dyspnoea and diaphoresis after a transient anopia on the background of hypertension, sickle cell trait and neurosurgical repair for spinal fluid leak. 1mm ST-elevation in anteroseptal leads without reciprocal changes and a minor troponin rise was identified. CT-PA excluded pulmonary embolism however indicated pericardial effusion. The first two echo studies demonstrated a pericardial effusion subcostally with the third revealing echocardiographic characteristics of hemopericardium with evidence of haemodynamic compromise, congruent with the clinical scenario of hypotension requiring fluid resuscitation. The finding of hemopericardium raised suspicion for aortic dissection or cardiac chamber perforation. CT aorta showed a penetrating ulcer within the proximal ascending aorta with mural thickening, extending from root to level of isthmus, representing a type A dissection. Successful conduit with coronary re-implantation, ascending aorta replacement and mechanical AVR were urgently pursued with desirable outcomes. In acute chest pain patients with high-risk features, the presence of pericardial haematoma should raise suspicion for acute aortic syndromes and prompt further investigation. This case highlights the importance of utilising all acoustic windows and the importance of identifying secondary features to aid in identification and intervention thus improving patient outcomes.

P1247 Bilateral endogenous endophthalmitis as the initial presentation of hacek prosthetic valve infective endocarditis

Abstract Summary A 75 year old lady with a prosthetic aortic valve (St Jude mechanical AVR) presented to ophthalmology with a one month history of black spots in the vision of her left eye with a further episode in her right eye two weeks later, leading to a diagnosis of bilateral endogenous endopthalmitis and was admitted to hospital. There was no history of trauma and the chest and abdominal examination was normal. The erythrocyte sedimentation rate (40) and C reactive protein (45.8) were elevated. She had several sets of blood cultures, which were positive for Aggregatibacter actinomycetemcomitans, a HACEK organism and was started on empirical Ceftriaxone. The transthoracic echocardiography was normal. However, the suspicion of Infective Endocarditis (IE) was high, therefore a transoesophageal echocardiography was performed and showed an aortic root abscess (Image 1). An urgent computerised aortogram was performed. Following a planned two week period of intravenous antibiotics the patient was taken to theatre to have a redo AV valve replacement and root repair. Following a prolonged period on intensive care and a six week course of pathogen directed antibiotic therapy she was then fit enough to be discharged. Conclusion We present the first case in the literature of a HACEK Prosthetic Valve endocarditis presenting with bilateral endogenous endophthalmitis. Abstract P1247 Figure. TOE image of Absess

10 YEAR FOLLOW-UP OF AORTIC VALVE REPLACEMENT OUTCOMES STRATIFIED BY TYPE AND BRAND OF VALVE

Recent reports have called into question published durability data around aortic valve prosthesis, some of the durability data. We sought to use detailed observational data from our centre to explore valve durability, specifically freedom from re-replacement, in a longitudinal cohort of patients who underwent surgical aortic valve replacement. The Maritime Heart Centre Database, which includes detailed data for any major cardiac surgery procedure including outcomes to discharge, was searched for surgical aortic valve replacement, including re-operations between January 2006 and December 2016. Patients were stratified by valve type at first surgery and the outcome of interest was a requirement for re-replacement of the prosthesis at any time during the study. Trifecta valves were only introduced in our centre in 2008, the remaining valves were available for the entire study period. During the study period valve implants by type were as follows: Mechanical AVR (SJM) 5.0% (134/2693); Carpentier Edwards Bioprosthesis 49.1% (1323/2693); SJM Epic Bioprosthesis 27.7% (746/2693); SJM Trifecta 18.1% (490/2693). Rates of re-replacement were as follows: Mechanical AVR (SJM) 4.5% (6/134); Carpentier Edwards Bioprosthesis 2.3% (30/1323); SJM Epic Bioprosthesis 2.8% (21/746); SJM Trifecta 2.0% (10/490). We found a high rate of re-replacement among mechanical aortic valves. The remaining valves were comparable in their freedom from re-replacement. Further work to explore the mechanism of valve failure is ongoing. We made the assumption that all re-replacements in this patient group would occur at our centre, which is the sole provider of cardiac surgery care in Nova Scotia.

ACUTE STEMI DUE TO MECHANICAL AV THROMBOSIS IN LIGHT OF NONCOMPLIANCE WITH ANTICOAGULATION THERAPY

Surgical AVR is the best Rx of severe AS by guidelines. Mechanical valves demand lifelong anticoagulation due to the high thrombogenicity. According to the ACC, the target INR is 2.5 if no additional risk factors are present. A 60 YO M. with a PMH of mechanical AVR who presented with severe

346 - Patients with Prosthetic Valves and Need for Left Ventricular Assist Device

Introduction: The use of left ventricular assist device (LVAD) in patients with prosthetic valves has been a subject of debate. The risk of thromboembolic (TE) events remains a concern especially if anticoagulation had to be interrupted in case bleeding occurs. Case Report: We report a case of a 63-year-old female with end-stage heart failure awaiting a heart transplant. She was admitted to the hospital for worsening chronic heart failure and was inotrope dependent. While awaiting heart transplant, a decision was made to implant a left ventricular assist device (LVAD) as a bridge to transplant. She had a mechanical mitral valve (mMVR) which was exchanged to a bioprosthetic valve at the time of LVAD implantation. Post-operative course was complicated by bleeding while she was on anticoagulation but she survived. Objectives and methods: We searched PubMed for case studies of patients with LVAD having bioprosthetic valves. We found retrospective studies and case reports from 1982 to 2010 on patients with LVAD and prosthetic valves. Only patients with permanent LVAD were analyzed (n = 37). These patients were further subgrouped into bioprosthetic mitral valve replacement (bMVR) and aortic valve replacement (bAVR); mechanical mitral valve replacement (mMVR) and aortic valve replacement (mAVR); and combined mechanical and bioprosthetic MVR and AVR. Moreover, we analyzed different eras of anticoagulation. Outcomes analyzed were TE events, bleeding and death. Results: Majority patients were bridged to warfarin as their anticoagulation regimen. Nine patients with mMVR had a mean LVAD support time of 168.2 days. Four patients with bMVR had a mean LVAD support time of 229.6 days. No clinical TE events or bleeds were reported in both these subgroups. Seven patients with mAVR had a mean LVAD support time of 47.57 days. Thrombus was found in one of the explanted heart, but no clinical TE events were reported. One patient had bleed. Eight patients with bAVR had a mean support time of 223.7 days. Thrombus was found underneath the aortic valve of the explanted heart of one patient. No bleeding or clinical TE events were noted. In the combination group, mean LVAD support time was 96.3 days. One patient had a bleeding complication. One patient had a TE event. Overall mortality was high in all subgroups ranging from 25% to 37.5% unrelated to TE event or bleed. Conclusion: Our analysis showed no significant TE events or bleeding complications in these patients. LVAD in patients with pre-existing prosthetic valves is worth consideration given the shortage of heart donors. We prefer exchanging the mechanical valve to a bMVR as it carries a lesser risk of TE events. However, one should be mindful of the overall high mortality rate in these patients. Larger studies need to be conducted to confirm these findings.

44 Can the principles of aortic root surgery in adults be safely applied to children

Objective Surgical algorithms for aortic root disease are established in adults. The root of children needs to have a potential for somatic growth, therefore a spectrum of techniques can be used to reconstruct the root. This study reviews a national experience in 50 consecutive paediatric patients requiring aortic root repair, and evaluates the efficacy of our treatment algorithm in this age group. Methods All aortic root procedures at our institution from 2001–2014 were reviewed. Follow-up was 100% complete. Patients undergoing aortic valve repair only (n = 7) or Ross/Konno procedures (n = 5) were excluded. Results There were 27 male patients. Mean age at surgery was 14.5 years (range: 4 weeks-18 years); mean weight was 46.1 kg (range: 3.5–105 kg). The predominant pathology was mixed disease of aortic stenosis (AS) / aortic incompetence (AI) in 28 /50, (AI) in 13/50 and (AS) in 1 /50. Aortic root dilatation (6 Marfan’s + 2 Loeys-Dietz syndrome) was the dominant pathology in 8/50 patients. 30/50 patients underwent a Ross procedure; 12/50 patients underwent aortic root replacement (ARR) with aortic homograft/biocomposite graft; 8/50 patients underwent David valve-sparing aortic root replacement (VSARR). There was 1 perioperative death (2%) with a 5 year actuarial survival of 98%. Mean follow up was 3.96 years (range: 0.1–11.6 years). There were no late mortalities. Re-intervention was required in 4/50 (8%); 1 Ross patient required (VSARR) for autograft dilatation, 2 required redo (ARR) with a composite graft for acute homograft failure, and 1 (VSARR) patient required mechanical AVR for AI. Conclusion Aortic root surgery in children can be accomplished with low rates of early-mid term re-intervention and mortality. Our experience confirms the applicability of adult treatment principles, and highlights the need for versatility in surgical technique in children.

Early Complications and Immediate Postoperative Outcomes of Paravalvular Leaks After Valve Replacement Surgery

To evaluate the incidence of perivalvular leaks (PVLs) after valve replacement and assess its impact on immediate postoperative outcomes. A retrospective review. A tertiary care university hospital. Four hundred forty-two consecutive patients undergoing aortic (AVR) and/or mitral (MVR) valve replacement. All patients had comprehensive intraoperative transesophageal echocardiography. Follow-up transthoracic echocardiography was performed at 5 to 7 days and 1 year after surgery. PVLs were classified as trace, mild, moderate, and severe. Perioperative variables including demographic data, surgical characteristics including the degree of valve calcification, and postoperative outcomes were compared between patients with and without PVLs. Multivariate logistic regression analysis was used to identify the variables predictive of PVLs. PVLs were identified in a total of 53 (12%) patients, 29 (13%) after MVR and 24 (11%) after AVR. At the 1-year transthoracic echocardiographic follow-up, 2 (7%) of 27 patients had residual PVLs after MVR and none after AVR. The duration of cardiopulmonary bypass (CPB) was predictive of PVLs. The presence of PVLs was associated with postoperative sepsis. The incidence of PVLs was similar after MVR and AVR. Bioprosthetic MVR and mechanical AVR were associated with higher-incidence PVLs when compared with controls. Mitral annular calcification was a potential risk factor for PVLs with bioprosthetic valves. The prolonged CPB time was predictive of PVLs. After adjusting for covariates, the overall presence of PVLs was associated with an increased risk of sepsis after surgery.

Effect of Valve Suture Technique on Incidence of Paraprosthetic Regurgitation and 10-Year Survival

The primary objective was to estimate the risk of paraprosthetic regurgitation (PPR) after aortic (AVR) and mitral valve replacement (MVR) using interrupted (IN) or semicontinuous (SC) sutures. The secondary objective was to estimate the risk of redo valve surgery and 10-year survival after valve replacement performed using either suture technique. Patients who underwent mechanical AVR or MVR using a St. Jude prosthesis between December 1991 and June 1997 were included. Eighteen patients had MVR and 43 had AVR using IN sutures; 49 and 83 patients received MVR and AVR, respectively, using SC sutures. The majority of these patients were part of a randomized controlled trial with different end points, presented elsewhere. Patients were followed for 10 years with annual transthoracic echocardiography, and clinical data were collected retrospectively. Kaplan-Meier survival analysis was performed. Cox's regression analysis was performed to identify factors predicting mortality as a function of time. Forward stepwise logistic regression was performed to analyze risk factors predicting PPR. Mann-Whitney U test was used for continuous and nonparametric data, and chi2 test and Fisher's exact test were used for categorical data. A probability value less than 0.05 was considered significant. The overall risk of PPR after MVR and AVR was higher in the SC group than in the IN group. The need for redo AVR was significantly higher in the SC group. The suture technique did not affect the 10-year survival after either AVR or MVR. Use of SC technique increases the risk of significant PPR after AVR and MVR compared with IN technique independent of the size of prosthesis, degree of annular calcification, disease of the excised valve, or the implanting surgeon. Although 10-year survival is independent of suture technique, SC technique increases the risk of redo valve replacement after AVR.

Percutaneous closure of an iatrogenic ventricular septal defect following mechanical aortic valve replacement using the transseptal technique

Iatrogenic ventricular septal defects (VSDs) following aortic valve replacement are relatively uncommon and are challenging to close percutaneously given their typical proximity to the prosthetic valve. We describe the successful percutaneous closure of an iatrogenic VSD in a patient with a recent mechanical AVR using the transseptal approach.

Results of bioprosthetic versus mechanical aortic valve replacement performed with concomitant coronary artery bypass grafting

Background. Concomitant coronary artery disease with aortic valve disease is an established risk factor for diminished late survival. This study evaluated the results of bioprosthetic (BAVR) or mechanical aortic valve replacement (MAVR) performed with coronary artery bypass grafting (CABG). Methods. From January 1984 through July 1997, combined AVR + CABG was performed in 750 consecutive patients; 469 received BAVR and 281 received MAVR. BAVR recipients were significantly older (mean age, 75 vs 65 years), and had more nonelective operations, congestive heart failure, peripheral vascular disease, preoperative intraaortic balloons, lower cardiac indices, more severe aortic stenosis, less aortic regurgitation, and more extensive coronary artery disease. Results. Early complications included operative mortality, 32 patients (4.3% total: 3.8% BAVR and 5.0% MAVR); perioperative infarction, 10 (1.3%); and perioperative stroke, 22 (2.9%). Significant multivariable predictors of early mortality were age, perioperative infarction or stroke, nonelective operation, operative year, ventricular hypertrophy, and need for intraaortic balloon. Ten-year actuarial survival was 41.7% for all patients. Predicted survival for age- and gender-matched cohorts from the general population versus observed survival were BAVR, 45% versus 36%; MAVR, 71% versus 48% (survival differences BAVR 9% vs MAVR 23%, p < 0.007). Significant multivariable predictors of late mortality included age, congestive failure, perioperative stroke, extent of coronary disease, peripheral vascular disease, and diabetes. Valve type was not significant. Ten-year actuarial freedom from valve-related complications were (BAVR vs MAVR) structural deterioration, 95% versus 100%, p = NS; thromboembolism, 86% versus 84%, p = NS; anticoagulant bleeding, 93% versus 88%, p < 0.005; reoperation, 98% versus 98%, p = NS. Conclusions. AVR + CABG has diminished late survival despite the type of prosthesis inserted. Although valve type did not predict late mortality, mechanical AVR was associated with worse survival compared with predicted and more valve-related complications due to anticoagulation requirements.

Reoperation for prosthetic aortic valve obstruction in the era of echocardiography: trends in diagnostic testing and comparison with surgical findings

OBJECTIVESWe sought to: 1) identify trends in the diagnostic testing of patients with prosthetic aortic valve (AVR) obstruction who undergo reoperation and 2) compare diagnostic test results with pathologic findings at surgery.BACKGROUNDIt is unclear whether Doppler transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) have reduced hemodynamic catheterization rates.METHODSWe reviewed 92 consecutive cases of AVR reoperation at a single center from 1989 to 1998, comparing 49 cases of mechanical AVR obstruction (group A) to 43 cases of bioprosthetic obstruction (group B). Preoperative Doppler TTE was performed in all cases.RESULTSIn group A cases, there was a marginally significant trend towards lower catheterization rates for the Gorlin AVR area, from 36% in 1989 to 1990 to 10% in 1997 to 1998 (p = 0.07), but diagnostic TEE utilization (47% of cases) did not vary. The cause of mechanical AVR obstruction was pannus in 26 cases (53%), mismatch (P-PM) in 19 (39%) and thrombosis in 4 (8%). The mechanism (pannus/thrombus vs. mismatch) was identified in 10% by TTE and 49% by TEE (p < 0.001). In group B cases, hemodynamic catheterization rates (21%) and diagnostic TEE utilization (21%) did not vary with time. Obstruction was caused by structural degeneration in 37 cases (86%), thrombosis in 3 (7%), mismatch in 2 (5%) and pannus in 1 (2%). The mechanism was correctly identified in 63% by TTE and in 81% by TEE (p = 0.18).CONCLUSIONSDoppler TTE is the primary means to diagnose AVR obstruction; hemodynamic catheterization is not routinely needed. In unselected patients with mechanical AVR obstruction, TEE differentiation of pannus or thrombus from mismatch is challenging.