Surgery for severe aortic stenosis with low transvalvular gradient and poor left ventricular function -- a single centre experience and review of the literature

Influence of Bentall Procedure on Left Ventricular Function

Objective

To evaluate the influence of Bentall procedure on left ventricular function and condition on long-term follow-up.

Methods

Seventy-three consecutive patients who underwent an aortic root and ascending aorta replacement with composite valve button Bentall or flanged Bentall technique, from January 2007 to November 2018, were included in this retrospective study.

Results

Postoperative left ventricular ejection fraction significantly increased (52.14±11.38 vs. 56.79±11.36; P=0.041), left ventricular end-systolic diameter significantly reduced (38.25±9.31 mm vs. 34.17±9.15 mm; P=0.027), left ventricular end-diastolic diameter significantly reduced (56.42±9.72 mm vs. 51.58±9.03 mm; P=0.01), and left atrial diameter significantly reduced (45.33±12.77 mm vs. 39.25±12.41 mm; P=0.01), compared to preoperative values. Our long-term survival results are comparable with previous studies in which survival rates in 5 years and 10 years were 83.5% and 69.8%, respectively. In comparing patients according to their New York Heart Association (NYHA) functional class, it was shown that their postoperative functional capacity was improved during the follow-up period (2.1±0.56 vs. 1.2±0.42; P=0.001).

Conclusion

The Bentall procedure significantly improved the left ventricular systolic function and condition and decreased the left ventricular end-systolic and end-diastolic diameters and the left atrial diameter on long-term follow-up, based on the transthoracic echocardiography. Bentall procedure can be performed with acceptable mortality and morbidity rates on long-term follow-up.

[Results of aortic valve replacement in patients with aortic stenosis associated with severe left ventricular dysfunction]

The operative risk of aortic valve replacement (AVR) due to tight aortic stenosis (AS) associated with severe left ventricular dysfunction is high. Several risk factors for postoperative mortality have been described, but most of the reported case series are heterogeneous. This study aimed to analyze the postoperative results of AVR in patients with isolated tight AS associated with severe left ventricular dysfunction and to identify predictive factors of in-hospital mortality. We conducted a retrospective study of 46 patients with tight AS associated with severe left ventricular dysfunction who had undergone AVR. The average age was 59±12.70 years. 69.6% of patients were in NYHA Class III or IV. Mean EF was 32.3 ± 5.3%, and mean EuroScore was 12.20 ± 8.70. In-hospital mortality accounted for 15.20%. Morbidity was mainly marked by low cardiac output in 35% of cases. Multivariate logistic regression analysis showed that renal insufficiency (OR= 11.94, CI [2.65-72.22], p= 0.03) and congestive cardiac failure (OR= 25.33, CI [3.43-194.74], p= 0.009) were related to the risk of in-hospital mortality. Thirty-nine surviving patients were followed up for an average of 59.6± 21 months. Late mortality accounted for 5%. The functional status had significantly improved. EF increased, on average, by 5.5 units in early postoperative period and by 18 units in late postoperative period. In the long term, end-diastolic and end-systolic diameters were reduced by an average of 8 and 9 mm, respectively. The results of AVR due to tight AS associated with severe left ventricular dysfunction are satisfactory. Congestive heart failure and preoperative renal failure are the main risk factors for in-hospital mortality. Patient's outcome is marked by reduction in end-diastolic and end-systolic diameters of the left ventricle with improvement of the EF and of their functional status.

Mechanical Intervention for Aortic Valve Stenosis in Patients With Heart Failure and Reduced Ejection Fraction

The risk and benefit of mechanical interventions in valvular heart disease have been primarily described among patients with normal ejection fraction. The advent of nonsurgical mechanical interventions for aortic stenosis (transcatheter aortic valve replacement) may alter the risk-benefit ratio for patients who would otherwise be at increased risk for valve surgery. This review describes the epidemiology and pathophysiology of aortic stenosis with heart failure and reduced ejection fraction and summarizes the current registry and clinical trial data applicable to this frequently encountered high-risk group. It concludes with discussion of ongoing trials, new approaches, emerging indications, and a potential clinical algorithm incorporating optimal mechanical intervention for patients with aortic stenosis and concomitant reduced ejection fraction.

Clinical presentation and outcomes after transcatheter aortic valve implantation in patients with low flow/low gradient severe aortic stenosis

OBJECTIVES

To identify predictors of mortality, functional status, and hemodynamical changes of patients undergoing transcatheter aortic valve implantation (TAVI) for low flow/low gradient aortic stenosis (LF/LG AS).

BACKGROUND

There is little published data regarding the outcomes of patients with LF/LG AS following TAVI.

METHODS

Sixty-eight patients with severe AS, left ventricular dysfunction (ejection fraction [EF] <35%) and low flow (LF) AS underwent TAVI. Patients were stratified according to the aortic mean pressure gradient (low gradient [LG]; with Pmean ≤40 mm Hg and high gradient [HG]: Pmean >40 mm Hg). The baseline parameters and clinical outcomes were subsequently compared among the two groups. Cox proportional hazards were used to identify predictors of 6-month mortality.

RESULTS

There were 38 patients in the LG group and 30 patients in the HG group. There were no significant difference in 30-day mortality between the two groups. The 6-month and 1-year mortality, however, was 3.8-fold and 2.8-fold higher in the LG group than in the HG group (37.8% vs. 10.3%, P = 0.01 and 37.8% vs. 13.3%, respectively, P = 0.01). Univariable predictors for 6-month mortality were: STS Score, aortic valve area, and aortic mean pressure gradient. However, only STS Score (HR 1.08, 1.04-1.12, P < 0.001) remained as independent predictor in the multivariable analysis. Six months after TAVI, hemodynamical (EF > 50%) and clinical (NYHA class I) improvements were shown in both HG and LG groups.

CONCLUSIONS

LF/LG AS does not influence procedural mortality after TAVI but exhibits a strong impact on 6-month and 1-year mortality. The survivors, however, exhibit considerable hemodynamical and clinical improvements. Therefore, risk stratification and TAVI benefit should be weighted in every patient with LF/LG AS.

Asymptomatic severe aortic stenosis with left ventricular dysfunction: watchful waiting or valve replacement?

Aortic stenosis (AS) is the most common valvular heart disorder in older adults. Patients with severe AS are generally treated nonsurgically if asymptomatic and referred to aortic valve replacement when symptoms develop. However, patients with severe asymptomatic AS with left ventricular dysfunction may benefit from early aortic valve replacement. Although operative mortality in patients with severe AS and left ventricular dysfunction is greater than in patients with preserved left ventricular function, the overall mortality risk is substantially lower than that of watchful waiting. Operative risk in patients with severe AS and left ventricular dysfunction is often overestimated and, consequently, most are not referred to surgery despite clinical data in support of early aortic valve replacement. Asymptomatic patients with echocardiographic confirmation of severe AS and left ventricular dysfunction should be referred for aortic valve replacement.