Patient-prosthesis mismatch after aortic valve replacement in the elderly

Impact of Prosthesis-Patient Mismatch After Surgical Aortic Valve Replacement: Systematic Review and Meta-Analysis of Reconstructed Time-to-Event Data of 122 989 Patients With 592 952 Patient-Years

BACKGROUND

It remains controversial whether prosthesis-patient mismatch (PPM) impacts long-term outcomes after surgical aortic valve replacement. We aimed to evaluate the association of PPM with mortality, rehospitalizations, and aortic valve reinterventions.

METHODS AND RESULTS

We performed a systematic review with meta-analysis of reconstructed time-to-event data of studies published by March 2023 (according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses). Sixty-five studies met our eligibility criteria and included 122 989 patients (any PPM: 68 332 patients, 55.6%). At 25 years of follow-up, the survival rates were 11.8% and 20.6% in patients with and without any PPM, respectively (hazard ratio [HR], 1.16 [95% CI, 1.13-1.18], P<0.001). At 20 years of follow-up, the survival rates were 19.5%, 12.1%, and 8.8% in patients with no, moderate, and severe PPM, respectively (moderate versus no PPM: HR, 1.09 [95% CI, 1.06-1.11], P<0.001; severe versus no PPM: HR, 1.29 [95% CI, 1.24-1.35], P<0.001). PPM was associated with higher risk of cardiac death, heart failure-related hospitalizations, and aortic valve reinterventions over time (P<0.001). Statistically significant associations between PPM and worse survival were observed regardless of valve type (bioprosthetic versus mechanical valves), contemporary PPM definitions unadjusted and adjusted for body mass index, and PPM quantification method (in vitro, in vivo, Doppler echocardiography). Our meta-regression analysis revealed that populations with more women tend to have higher HRs for all-cause death associated with PPM.

CONCLUSIONS

The results of the present study suggest that any degree of PPM is associated with poorer long-term outcomes following surgical aortic valve replacement and provide support for implementation of preventive strategies to avoid PPM after surgical aortic valve replacement.

Midterm outcomes after surgical aortic valve replacement with the INSPIRIS RESILIA from a multicenter AVR registry

BACKGROUND

There have been few reports on the mid- to long-term safety and efficacy validation of the INSPIRIS RESILIA aortic bioprosthesis (Edwards Lifesciences LLC, Irvine, CA, USA) in Japan. Herein, we report the mid-term results of surgical aortic valve replacement (AVR) for aortic stenosis using INSPIRIS and evaluate the hemodynamics compared to the CEP Magna series from the multicenter AVR registry (the ACTIVIST registry).

METHODS

Of the 1967 patients who underwent surgical or transcatheter AVR from the ACTIVIST registry, 66 patients who underwent isolated surgical AVR with INSPIRIS by December 2020 were included in this study, and the early and mid-term results were evaluated. Hemodynamics were evaluated by comparing 272 patients undergoing isolated surgical AVR with the Magna group using propensity score matching.

RESULTS

The mean age was 74.0 ± 7.8 years, and 48.5 % were women. In-hospital mortality was 1.5 %, and the survival rates at 1- and 2-years were 95.2 % and 95.2 %, respectively. After propensity score matching, echocardiographic findings at discharge demonstrated that peak velocity and mean pressure gradient in the INSPIRIS group were comparable, while the effective orifice area in the INSPIRIS group was significantly larger than those in the Magna group (p = 0.048). A patient-prosthesis mismatch at discharge was significantly lower in the INSPIRIS group (11.8 %) than in the Magna group (36.4 %) (p = 0.004).

CONCLUSIONS

Surgical AVR with INSPIRIS was performed safely and the mid-term results were satisfactory. The hemodynamics of INSPIRIS were comparable to those of Magna.

Patient Prosthesis Mismatch After SAVR and TAVR

Patient-prosthesis mismatch (PPM) remains one out of many factors to be considered during decision-making for the treatment of aortic valve pathologies. The idea of adequate sizing of a prosthetic heart valve was established by Rahimtoola already in 1978. In this article, the author described the phenomenon that the orifice area of a prosthetic heart valve may be too small for the individual patient. PPM is assessed by measurement or projection of the prosthetic effective orifice area indexed to body surface area (iEOA), while it is recommended to use different cut point values for non-obese and obese patients for the categorization of moderate and severe PPM. Several factors influence the accuracy of both the projected and the measured iEOA for PPM assessment, which leads to a certain number of false assignments to the PPM or no PPM group. Despite divergent findings on the impact of PPM on clinical outcomes, there is consensus that PPM should be avoided to prevent sequelae of increased prosthetic gradients after aortic valve replacement. To prevent PPM, it is required to anticipate the iEOA of the prosthesis prior to the procedure. The use of adequate reference tables, derived from echocardiographically measured mean effective orifice area (EOA) values from preferably large numbers of patients, is most appropriate to predict the iEOA. Such tables should be used also for transcatheter heart valves in the future. During the decision-making process, all available options should be taken into account for the individual patient. If the predicted size and type of a surgical prosthesis cannot be implanted, additional surgical procedures, such as annular enlargement with the Manougian technique, or alternative procedures, such as transcatheter aortic valve implantation (TAVI) can prevent PPM. PPM prevention for TAVI patients is a new field of interest and includes anticipation of the iEOA, prosthesis selection, and procedural strategies.

Patient-prosthesis mismatch following aortic valve replacement

Patient-prosthesis mismatch (PPM) occurs when an implanted prosthetic valve is too small for the patient; severe PPM is defined as an indexed effective orifice area (iEOA) <0.65 cm2/m2 following aortic valve replacement (AVR). This review examines articles from the past 10 years addressing the prevalence, outcomes and options for prevention and treatment of PPM after AVR. Prevalence of PPM ranges from 8% to almost 80% in individual studies. PPM is thought to have an impact on mortality, mainly in patients with severe PPM, although severe PPM accounts for only 10–15% of cases. Outcomes of patients with moderate PPM are not significantly different to those without PPM. PPM is associated with higher rates of perioperative stroke and renal failure and lack of left ventricular mass regression. Predictors include female sex, older age, hypertension, diabetes, renal failure and higher surgical risk score. PPM may be a marker of comorbidity rather than a risk factor for adverse outcomes. PPM should be suspected in patients with persistent cardiac symptoms after AVR when there is high prosthetic valve velocity or gradient and a small calculated effective orifice area. After exclusion of other causes of increased transvalvular gradient, re-intervention may be considered if symptoms persist and are unresponsive to medical therapy. However, this decision needs to consider the available options to relieve PPM and whether expected benefits justify the risk of intervention. The only effective intervention is redo surgery with implantation of a larger valve and/or annular enlargement. Therefore, focus needs to be on prevention.

Update on aortic valve prosthesis-patient mismatch in Japan

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