Prosthesis-patient mismatch causes a significantly increased risk of operative mortality in aortic valve replacement.

BACKGROUND: Small aortic prosthesis can lead to prosthesis-patient mismatch (PPM). Implanting such small prosthesis remains a controversial issue. This study was done to investigate whether or not PPM causes an increased operative mortality in aortic valve replacement (AVR). METHODS: Two-hundred-two consecutive patients undergoing primary AVR in a tertiary hospital were included. The sample was grouped according to the aortic valve prosthesis size: ≤21 mm (small) and >21 mm (standard). The effect of variables on outcomes was determined by univariate and multivariable regression analyses. RESULTS: PPM was found significantly more among patients with AVR ≤ 21 mm (P < 0.0001). Moreover, the likelihood of mortality also was significantly higher in these patients (P < 0.0001). Univariate analysis demonstrated small prosthesis size, urgent operation, PPM, female gender, and NYHA Class IV as significant predictors of mortality. Multivariate regression identified female gender, PPM, and urgent operation as the key independent predictors of mortality. CONCLUSION: PPM and female gender are significant predictors of mortality. Care should be taken to prevent PPM by implanting larger prosthesis especially in females.

10-year results of the uncemented Allofit press-fit cup in young patients.

BACKGROUND AND PURPOSE: Uncemented acetabular components in primary total hip arthroplasty (THA) are commonly used today, but few studies have evaluated their survival into the second decade in young and active patients. We report on a minimum 10-year follow-up of an uncemented press-fit acetabular component that is still in clinical use. METHODS: We examined the clinical and radiographic results of our first 121 consecutive cementless THAs using a cementless, grit-blasted, non-porous, titanium alloy press-fit cup (Allofit; Zimmer Inc., Warsaw, IN) without additional screw fixation in 116 patients. Mean age at surgery was 51 (21-60) years. Mean time of follow-up evaluation was 11 (10-12) years. RESULTS: At final follow-up, 8 patients had died (8 hips), and 1 patient (1 hip) was lost to follow-up. 3 hips in 3 patients had undergone acetabular revision, 2 for deep infection and 1 for aseptic acetabular loosening. There were no impending revisions at the most recent follow-up. We did not detect periacetabular osteolysis or loosening on plain radiographs in those hips that were evaluated radiographically (n = 90; 83% of the hips available at a minimum of 10 years). Kaplan-Meier survival analysis using revision of the acetabular component for any reason (including isolated inlay revisions) as endpoint estimated the 11-year survival rate at 98% (95% CI: 92-99). INTERPRETATION: Uncemented acetabular fixation using the Allofit press-fit cup without additional screws was excellent into early in the second decade in this young and active patient cohort. The rate of complications related to the liner and to osteolysis was low.

Clinical predictors of prosthesis-patient mismatch after aortic valve replacement for aortic stenosis.

OBJECTIVE: We sought to ascertain predictors of Patient Prosthesis Mismatch, an independent predictor of mortality, in patients with aortic stenosis using bioprosthetic valves. METHOD: We analyzed 2,107 sequential surgeries. Patient Prosthesis Mismatch was calculated using the effective orifice area of the prosthesis divided by the patient's body surface area. We defined nonsignificant, moderate, and severe Patient Prosthesis Mismatch as effective orifice area indexes of .0.85 cm(2)/m, 0.85-0.66 cm(2)/m(2), and <0.65 cm(2)/m(2), respectively. RESULTS: A total of 311 bioprosthetic patients were identified. The incidence of nonsignificant, moderate, and severe Patient Prosthesis Mismatch was 41%, 42, and 16%, respectively. Severe Patient Prosthesis Mismatch was significantly more prevalent in females (82%). In severe Patient Prosthesis Mismatch, the perfusion and the crossclamp times were considerably lower when compared with nonsignificant Patient Prosthesis Mismatch and moderate Patient Prosthesis Mismatch. Patients with severe Patient Prosthesis Mismatch had a significantly higher likelihood of spending time in the intensive care unit and a significantly longer length of stay in the hospital. Body surface area was not different in severe Patient Prosthesis Mismatch when compared with nonsignificant Patient Prosthesis Mismatch. In-hospital mortality in patients with nonsignificant, moderate, and severe Patient Prosthesis Mismatch was 2.3%, 6.1%, and 8%, respectively. Minimally invasive surgery was significantly associated with moderate Patient Prosthesis Mismatch in 49% of the patients, but not with severe Patient Prosthesis Mismatch. CONCLUSION: Severe Patient Prosthesis Mismatch is more common in females, but not in those with minimal available body surface area. Though operative times were shorter in these patients, intensive care unit and hospital lengths of stay were longer. Surgeons and cardiologists should be cognizant of these clinical predictors and complications prior to valve surgery.

Clinical predictors of prosthesis-patient mismatch after aortic valve replacement for aortic stenosis

OBJECTIVE: We sought to ascertain predictors of Patient Prosthesis Mismatch, an independent predictor of mortality, in patients with aortic stenosis using bioprosthetic valves. METHOD: We analyzed 2,107 sequential surgeries. Patient Prosthesis Mismatch was calculated using the effective orifice area of the prosthesis divided by the patient's body surface area. We defined nonsignificant, moderate, and severe Patient Prosthesis Mismatch as effective orifice area indexes of .0.85 cm²/m, 0.85-0.66 cm²/m², and <0.65 cm²/m², respectively. RESULTS: A total of 311 bioprosthetic patients were identified. The incidence of nonsignificant, moderate, and severe Patient Prosthesis Mismatch was 41 percent, 42, and 16 percent, respectively. Severe Patient Prosthesis Mismatch was significantly more prevalent in females (82 percent). In severe Patient Prosthesis Mismatch, the perfusion and the crossclamp times were considerably lower when compared with nonsignificant Patient Prosthesis Mismatch and moderate Patient Prosthesis Mismatch. Patients with severe Patient Prosthesis Mismatch had a significantly higher likelihood of spending time in the intensive care unit and a significantly longer length of stay in the hospital. Body surface area was not different in severe Patient Prosthesis Mismatch when compared with nonsignificant Patient Prosthesis Mismatch. In-hospital mortality in patients with nonsignificant, moderate, and severe Patient Prosthesis Mismatch was 2.3 percent, 6.1 percent, and 8 percent, respectively. Minimally invasive surgery was significantly associated with moderate Patient Prosthesis Mismatch in 49 percent of the patients, but not with severe Patient Prosthesis Mismatch. CONCLUSION: Severe Patient Prosthesis Mismatch is more common in females, but not in those with minimal available body surface area. Though operative times were shorter in these patients, intensive care unit and hospital lengths of stay were longer. Surgeons and cardiologists should be cognizant of these clinical predictors and complications prior to valve surgery.

Impact of the indexed effective orifice area on mid-term cardiac-related mortality after aortic valve replacement.

BACKGROUND: There has been ongoing controversy as to whether prosthesis-patient mismatch (PPM, defined as indexed effective orifice area (EOAI) <0.85 m(2)/cm(2)) influences mortality after aortic valve replacement (AVR). In most studies, PPM is anticipated by reference tables based on mean EOAs as opposed to individual assessment. These reference values may not reflect the actual in vivo EOAI and hence, the presence or absence of PPM may be based on false assumptions. OBJECTIVE: To assess the impact of small prosthesis EOA on survival after aortic valve replacement AVR. METHODS: 645 patients had undergone an AVR between 2000 and 2007 entered the study. All patients underwent transthoracic echocardiography for determination of the actual EOAI within 6 months postoperatively. In order to predict time from surgery to death a proportional hazards model for competing risks (cardiac death vs death from other causes) was used. EOAI was entered as a continuous variable. RESULTS: PPM occurred in 40% of the patients. After a median follow-up of 2.35 years, 92.1% of the patients were alive. The final Cox regression model showed a significantly increased risk for cardiac death among patients with a smaller EOAI (HR=0.32, p=0.022). The effect of EOAI on the 2-5 year mortality risk was demonstrated by risk plots. CONCLUSIONS: In contrast to previous studies these EOAI values were obtained through postoperative echocardiography, substantially improving the accuracy of measurement, and the EOAI was modelled as a continuous variable. There was a significantly improved survival for larger EOAIs following AVR. Strategies to avoid PPM should become paramount during AVR.

Influence of prosthesis-patient mismatch on exercise-induced arrhythmias: a further aspect after aortic valve replacement.

OBJECTIVES: The influence of prosthesis-patient mismatch on outcome after aortic valve replacement is controversial. This study analyzed the impact of prosthesis-patient mismatch on survival, the extent of left ventricular mass, and physical capacity after replacement with a small-size prosthesis. PATIENTS AND METHODS: A total of 157 patients who underwent valve replacement for pure aortic stenosis were reviewed. Late mortality, morbidity, left ventricular mass regression, transprosthetic gradient at rest and after exercise, exercise capacity, and occurrence of arrhythmias were evaluated. RESULTS: Prosthesis-patient mismatch, defined as an indexed effective orifice area of 0.75 cm(2)/m(2) or more, occurred in 96 (61.1%) patients and had no significant impact on early and late mortality. The only independent predictor of mortality was age greater than 65 years. At follow-up, multivariate analysis of prosthetic gradient at rest of 35 mm Hg end exercise capacity or more revealed that both these evidences were associated with high left ventricular mass (P < .001), female gender (P < .001), and follow-up time (P < .001). Arrhythmias occurred during exercise in 34.1% of patients (40/117). Multivariate analysis of occurrence of arrhythmias revealed that they were associated with high mean transprosthetic gradients: values of 50 mm Hg or more during exercise had 95% sensitivity and 72% specificity for predicting arrhythmias. CONCLUSION: Prosthesis-patient mismatch failed to demonstrate any significant impact on early and late mortality and morbidity and in left ventricular mass regression. High transprosthetic gradients influence exercise capacity and occurrence of arrhythmias.

[The impact of the "patient - prosthesis mismatch" in patients with aortic valve replacement.]. / Impacto do "patient-prosthesis mismatch" em doentes submetidos a substituição valvular aórtica.

UNLABELLED: Patient-Prosthesis Mismatch (PPM) is still a controversial matter in our days. We have PPM when the orifice area of an implanted aortic prosthesis valve is too small for the body surface area of an individual; this is, when the orifice area indexed to the body surface area is <0.8-0.9 cm2/m2. OBJECTIVE: Assess the impact of Patient-Prosthesis Mismatch in the short term and 2 years follow up in a group of patients submitted to aortic valve replacement. MATERIAL AND METHODS: The authors present a retrospective study involving 343 patients with a mean age of 64,68+/-12,4 years that were submitted to aortic valve replacement between January 2005 and December 2008. Data were collected from patients' files and direct contact with the patients, comparing the groups with and without PPM and correlating them in terms of Euroscore, demographics, type of implanted prosthesis, surgical times, ICU and hospital stay. The data related to short term and long term mortality as well as the NYHA class evolution were also obtained. RESULTS: Using the cut-off related to effective orifice area index 0,9 cm2/m2 we found PPM in 109 patients (31.7%). When comparing the two groups, we found that PPM seems to be related to advanced age (p=0.001), biological prosthesis (p=0.01) and, as expected, with use of valves less than 21 (p<0,05). A statistical significant difference was found for: 1) short-term mortality in patients with PPM (p<0,001), however, there were no differences in 2 years mortality and NYHA class between the groups; 2) aorta's cross clamping and extra corporeal circulation time (p=0.047 and p=0.036, respectively).

Patient-prosthesis mismatch does not affect survival following aortic valve replacement.

OBJECTIVE: Patient-prosthesis mismatch (PPM) has been reported to increase perioperative mortality and reduce postoperative survival in patients undergoing aortic valve replacement (AVR). We analysed the effect of PPM at values predicting severe mismatch on survival following AVR in our unit. METHODS: Prospectively collected data on 1481 consecutive patients who had undergone AVR with or without coronary artery revascularisation between 1997 and 2005 were analysed. Projected in vitro valve effective orifice area (EOA) and geometric prosthesis internal orifice area (GOA) were evaluated and values were indexed to body surface area (cm(2)m(-2)). PPM was defined as EOAi<0.6 and/or GOAi<1.1. Long-term survival data were obtained from the National Institute of Statistics. RESULTS: One thousand four hundred and eighteen patients were identified. 67/1418 (4.7%) patients had GOAi<1.1; 122/1418 (8.6%) had EOAi<0.6 and 38 (2.6%) patients exhibited both forms of mismatch. One thousand two hundred and sixty-seven patients (89%) demonstrated no mismatch (reference group). There were 75 in-hospital deaths (overall mortality 5.3%) with no significant difference between the mismatch and the reference groups. Survival data were available for up to 8 years (median 36 months, IQR 6-60 months). There were 160 late deaths (13/143 PPM group vs 147/1198 reference group). The 5-year survival estimate was similar for both groups (83% PPM group; 81% reference group; p=0.47). Cox-hazard analysis identified advanced age as the only predictor of reduced survival (age>80, RR 2.13, 95% CI 1.38-4.586, p=0.004). CONCLUSIONS: Severe patient-prosthesis mismatch was predicted in 4-10% of patients undergoing AVR but this did not affect in-hospital mortality or mid-term survival.