Influence of Prosthesis–Patient Mismatch on Diastolic Heart Failure After Aortic Valve Replacement

Aortic valve replacement and prosthesis-patient mismatch in the era of trans-catheter aortic valve implantation

Objective

The treatment strategy for aortic stenosis (AS) has been changing due to newly developed valvular prostheses and trans-catheter aortic valve implantation (TAVI). To determine the role of new modalities for AS with a small aortic root, papers using the concept of prosthesis-patient mismatch (PPM) were reviewed.

Methods

First, to determine the cut-off value of the indexed effective orifice area (IEOA) for defining PPM, the studies of surgical aortic valve replacement (SAVR) with a follow-up longer than 5 years and a patient number larger than 500 were reviewed. Second, the papers comparing TAVI and SAVR were reviewed. Furthermore, the prevalence of PPM was reviewed, with the addition of papers on aortic root enlargement, sutureless AVR, and aortic valve reconstruction with autologous pericardium.

Results and conclusion

The results of the long-term survival after aortic valve replacement (AVR) have indicated that an IEOA less than 0.65 cm²/m² should be avoided in all cases, whereas the indications for patients with an IEOA between 065 and 0.85 cm²/m² should be determined by considering multiple factors. A large body size and younger age have a significantly negative influence on the long-term survival. In Asian population, the prevalence of PPM was low, despite the fact that the size of the aortic annulus was small. The IEOA after TAVI was larger than after surgical AVR in population-matched studies. To evaluate the role of TAVI and other modalities for a small aortic root, studies with a longer follow-up and larger volume are thus warranted.

Intraoperative cardiac assessment with transesophageal echocardiography for decision-making in cardiac anesthesia

Transesophageal echocardiography is an invaluable hemodynamic monitoring modality. Extended and anatomically based evaluation of cardiac function with transesophageal echocardiography is essential to prompt and accurate decision-making in anesthetic management during cardiac surgery. Fractional shortening and fractional area changes are indices widely used to assess the global systolic performance of the left ventricle. Monitoring regional function using semi-quantitative scoring has been demonstrated to be a more sensitive indicator of myocardial ischemia. Assessment of left ventricular diastolic function should be performed in a systematic way, measuring transmitral flow, pulmonary venous flow, transmitral color M-mode flow propagation velocity, and mitral annulus tissue Doppler imaging. The unique anatomical features of the right ventricle make echocardiographic evaluation complicated and therefore less frequently employed. Right ventricular fractional area change, tricuspid annular plane systolic excursion, maximal systolic tricuspid annular velocity with tissue Doppler imaging, and myocardial performance index are indices successfully incorporated into intraoperative right ventricular assessment. Left ventricular outflow tract obstruction with systolic anterior motion of the mitral valve may develop after cardiac procedures. Transesophageal echocardiography plays a central role in prevention as well as diagnosis of systolic anterior motion. Transesophageal echocardiography is extremely useful not only for detecting and locating intracardiac air, but also for guiding and evaluating the procedures to remove air. Air is likely to persist in the right and left superior pulmonary vein, left ventricular apex, left atrium, right coronary sinus of Valsalva, and ascending aorta. Accurate evaluation of cardiac function depends on performing TEE examination properly and obtaining optimal images.

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.

Clinical and echocardiographic outcomes after implantation of the Trifecta aortic bioprosthesis: an initial single-centre experience

OBJECTIVES

The Trifecta valve (St. Jude Medical) was introduced into clinical practice as a tri-leaflet stented pericardial valve designed for supra-annular placement in the aortic position. The present study aims to evaluate the preliminary results with this new bioprosthesis.

METHODS

Seventy patients underwent aortic valve replacement (AVR) with the Trifecta valve between August 2010 and December 2011. Thirty-three patients were male and 37 were female (52.9%). Mean age was 74.65 ± 7.63 (range 47-90 years). Prevalent cause of AVR was aortic stenosis in 64 (91.43%) patients. The mean preoperative pressure gradient was 50 ± 17 (range 20-84 mmHg), and the mean aortic valve area was 0.77 ± 0.33. Five (7.14%) patients were operated on due to aortic valve endocarditis. One patient was operated on due to isolated, severe aortic insufficiency. All patients were in New York Heart Association functional class III or IV. Twenty-eight (40%) patients underwent concomitant procedures.

RESULTS

Concomitant procedures were coronary artery bypass grafting (n = 25), mitral valve replacement (n = 1), ablation of atrial fibrillation (n = 1) and septal myomectomy (n = 1). There were no intraoperative deaths. The 30-day in-hospital mortality was 2.85% (2 of 70). One late death occurred during the in-hospital stay due to a multiorgan failure on postoperative day 60. There were 2 (2.85%) perioperative strokes. Mean pressure gradient decreased significantly from a preoperative value of 50 ± 17 mmHg to an intraoperative gradient of 9 ± 4 mmHg (Table 3). The mean gradients were 14, 11, 11, 8 and 6 mmHg for the 19, 21, 23, 25 and 27 mm valve size, respectively. No prosthesis dislocation, endocarditis, valve thrombosis or relevant aortic regurgitation was observed at discharge.

CONCLUSIONS

The initial experience with the Trifecta valve bioprosthesis shows excellent outcomes with favourable early haemodynamics. Further studies with longer follow-up are needed to confirm those preliminary results.

Mid-term evaluation of Sorin Soprano bioprostheses in patients with a small aortic annulus <or=20 mm

We set to examine the mid-term outcome after aortic valve replacement (AVR) with Soprano pericardial stented bioprosthesis measuring <or=20 mm. Sixty-eight patients underwent AVR between June 2003 and January 2006 (50 women; median age 77 years; range 60-89 years). Preoperatively, 60 patients (88.2%) were in New York Heart Association (NYHA) class III/IV. The mean EuroSCORE was 6.7+/-2.3. Supra-annular aortoplasty was performed in 21 patients (30.9%), out of which 11 patients received an 18 mm prosthesis (55%). The median follow-up was 45.5 months (0.1-62 months). The 30-day mortality was 4.4% (n=3) with no early valve-related deaths. No patient suffered a cerebrovascular accident and no patient required replacement of prosthesis for coronary malperfusion. Postoperatively, the mean gradient across the 18 mm bioprosthesis (n=20) was 25+/-8.9 mmHg and across the 20 mm bioprosthesis (n=48) was 25.5+/-7.3 mmHg (P=NS). During follow-up, there was no valve-related death, re-operation for structural valve degeneration, endocarditis or valve thrombosis. There were five late deaths and actuarial survival at three and five years was 92.7+/-3.1% and 81.0+/-6.9%, respectively. At last follow-up, 86.7% (n=52) of survivors were in NYHA class I/II. AVR with Soprano bioprosthesis measuring <or=20 mm is associated with excellent mid-term outcome. Continued follow-up is required to determine the long-term efficacy of the prosthesis.

Interaction and prognostic effects of left ventricular diastolic dysfunction and patient-prosthesis mismatch as determinants of outcome after isolated aortic valve replacement

There are variable reported effects of patient-prosthesis mismatch (P-PM) on outcome. It was hypothesized that the adverse effect attributed to P-PM is actually due to left ventricular diastolic dysfunction (DD) in patients with small hearts. The aim of this study was therefore to determine the association among P-PM, DD, and outcomes. Doppler echocardiography was performed in 156 patients after aortic valve replacement. In vivo effective orifice areas for each prosthesis type and size were obtained from published references values of normally functioning prostheses. P-PM was identified from the predicted indexed orifice area, obtained by dividing the effective orifice area by body surface area. DD was classed as normal, delayed relaxation (prolonged deceleration time for age), or increased left atrial pressure (increased E/E' ratio, left atrial enlargement, short deceleration time). Events (cardiac-related hospitalizations and all-cause mortality after aortic valve replacement) were determined over a median follow-up periods of 3.5 years (interquartile range 2.1 to 5.7). P-PM was found in 91 patients (58%). Of the patients with P-PM, no DD was present on postoperative echocardiography in 15 patients (16%), delayed relaxation in 35 (39%), and increased left atrial pressure in 41 (45%). There were 61 total events (18 deaths and 43 hospitalizations): 4 (7%) in the no-DD group, 26 (42%) in the delayed relaxation group, and 31 (51%) in the increased left atrial pressure group. DD (p = 0.034) but not age (p = 0.09), the left ventricular ejection fraction (p = 0.60), or the presence of mismatch (p = 0.20) was associated with events. In conclusion, P-PM was associated with 14% mortality and a 39% composite event rate over 2-year follow-up. Events were significantly associated with DD.