Risk Prediction in Aortic Valve Replacement: Incremental Value of the Preoperative Echocardiogram

Abstract

BackgroundRisk prediction is a critical step in patient selection for aortic valve replacement (AVR), yet existing risk scores incorporate very few echocardiographic parameters. We sought to evaluate the incremental predictive value of a complete echocardiogram to identify high‐risk surgical candidates before AVR.Methods and ResultsA cohort of patients with severe aortic stenosis undergoing surgical AVR with or without coronary bypass was assembled at 2 tertiary centers. Preoperative echocardiograms were reviewed by independent observers to quantify chamber size/function and valve function. Patient databases were queried to extract clinical data. The cohort consisted of 432 patients with a mean age of 73.5 years and 38.7% females. Multivariable logistic regression revealed 3 echocardiographic predictors of in‐hospital mortality or major morbidity: E/e’ ratio reflective of elevated left ventricular (LV) filling pressure; myocardial performance index reflective of right ventricular (RV) dysfunction; and small LV end‐diastolic cavity size. Addition of these echocardiographic parameters to the STS risk score led to an integrated discrimination improvement of 4.1% (P<0.0001). After a median follow‐up of 2 years, Cox regression revealed 5 echocardiographic predictors of all‐cause mortality: small LV end‐diastolic cavity size; LV mass index; mitral regurgitation grade; right atrial area index; and mean aortic gradient <40 mm Hg.ConclusionsEchocardiographic measures of LV diastolic dysfunction and RV performance add incremental value to the STS risk score and should be integrated in prediction when evaluating the risk of AVR. In addition, findings of small hypertrophied LV cavities and/or low mean aortic gradients confer a higher risk of 2‐year mortality.

Natural history of severe aortic stenosis: Diastolic wall strain as a novel prognostic marker

“…These include myocardial extracellular matrix dysfunction, worsening myocardial fibrosis, decreased ventricular compliance, abnormal diastolic filling, and eventual CHF. Therefore, delaying AVI until symptoms develop is controversial …”

Preoperative Left Ventricular Diastolic Dysfunction and One-Year Survival in Patients Undergoing Transcatheter Aortic Valve Replacement

“…structural data has been shown to provide incremental prognostic value in patients undergoing both coronary artery bypass grafting (CABG) and surgical aortic valve replacement (SAVR). [1][2][3] Studies have shown preoperative transthoracic echocardiographic parameters such as left ventricular systolic function, severity of mitral regurgitation, and tricuspid regurgitation to be associated with increased major adverse cardiac events or mortality after transcatheter aortic valve replacement (TAVR). [4][5][6] While much emphasis has been placed on systolic function of the left ventricle, until recently the relevance of preoperative left ventricular diastolic dysfunction (LVDD) on clinical outcomes after TAVR has received significantly less attention.…”

“…7 Given the prevalence of LVDD in patients with aortic stenosis and its reported association with major adverse cardiac events after CABG and SAVR, an investigation of its impact on outcomes in the TAVR patient population is desperately needed. 2,8 We considered the possibility that patients with worse preoperative LVDD as assessed using (1) E/e' ratio, (2) left atrial volume index (LAVI), and (3) left ventricular mass index (LVMI) would have increased mortality after TAVR at 1 year postoperatively. After institutional approval, we reviewed our own single institutional TAVR experience at the time comprising 123 patients including all access routes.…”

“…Of note, our finding was consistent with other research that found no statistically significant association between preoperative LAVI and mortality after both SAVR and TAVR. 2,7 In contrast to our other metrics, only 15 patients were excluded from LVMI analysis. These were patients without a recorded LVMI, those who died from immediate procedural complications, and those who were lost to follow-up.…”

“…While E/e' has demonstrated potential prognostic relevance in a number of studies including this one, its correlation with left atrial pressures in a number of clinical contexts, including aortic stenosis, has been recently challenged. 2,8,[10][11][12][13] Indeed, this leaves us with an uncomfortable question: what are we in fact measuring in physiologic terms when we divide the peak velocity of passive filling by the velocity of the lateral annulus, or E/e'? Importantly, we only were able to apply this metric in just over half of our population, suggesting that while it may have prognostic significance, it appears to have limited clinical applicability in this patient cohort.…”