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

Abstract

Background There has been ongoing controversy as to whether prosthesisepatient 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 (HR¼0.32, p¼0.022). The effect of EOAI on the 2e5 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.

Comparison Between Transcatheter and Surgical Prosthetic Valve Implantation in Patients With Severe Aortic Stenosis and Reduced Left Ventricular Ejection Fraction

“…In this regard, it is important to emphasize that a ventricle with depressed systolic function is highly sensitive to an increase in afterload, especially during the periprocedural period during which the myocardial function is more vulnerable. [12][13][14] The difference in postprocedural gradient between the 2 groups nonetheless appears smaller than one would expect from the observed difference in indexed AVA and from the average value of indexed AVA of the SAVR group, which is located on the steep portion of the gradient-indexed AVA curve ( Table 2). The relationship between indexed AVA and gradient indeed follows an inverse exponential function.…”

“…Persistent afterload excess after SAVR may indeed have a highly detrimental impact on postoperative hemodynamic and clinical outcomes in these high-risk patients. [12][13][14] In some patients, optimal relief of valvular obstruction can be achieved by implantation of a new generation of stented bioprosthetic or bileaflet mechanical valves implanted in the supra-annular position. In other patients, however, the surgeon may have to perform more invasive procedures such as implantation of a stentless bioprosthesis or enlargement of the aortic root to achieve optimal hemodynamics and to avoid prosthesis-patient mismatch.…”

“…11 In this regard, previous studies have shown that patients with depressed LV systolic function are extremely sensitive to the residual pressure overload imposed by prosthesis-patient mismatch. [12][13][14] Moreover, the ischemic, oxidative stress, and inflammatory injuries associated with open heart surgery induce apoptosis of a significant proportion of cardiomyocytes, which may compromise postoperative recovery of myocardial function. 15,16 We thus hypothesized that TAVI would be associated with better recovery of LVEF compared with SAVR.…”

The effects of implanted valve sizes on ventricular hypertrophy in aortic stenosis

“…Takılan protez kapakların da bir orifis alanının olduğu ve dar ölçülerdeki protez kapağın rezidüel bir basınç gradiyentine neden olabileceği unutulmamalıdır. Ancak, AVR yapılan hastalarda ek sistemik hastalık varlığı kadar takılan kapağın ölçüsü de mortaliteyi direkt etkilemektedir (6).…”

Prevalence and Long-Term Outcome of Aortic Prosthesis–Patient Mismatch in Patients With Paradoxical Low-Flow Severe Aortic Stenosis

“…However, the EOA expressed as a continuous variable was associated with poorer long-term survival in multivariable analyses, which is consistent with previous studies. 15,24,25,28 …”