Persistence of Reduced Left Ventricular Function after Aortic Valve Surgery for Aortic Valve Regurgitation: Bicuspid versus Tricuspid

Cardiac T1 mapping enables risk prediction of LV dysfunction after surgery for aortic regurgitation

Background

To assess whether cardiac T1 mapping for detecting myocardial fibrosis enables preoperative identification of patients at risk for early left ventricular dysfunction after surgery of aortic regurgitation.

Methods

1.5 Tesla cardiac magnetic resonance imaging was performed in 40 consecutive aortic regurgitation patients before aortic valve surgery. Native and post-contrast T1 mapping was performed using a modified Look-Locker inversion-recovery sequence. Serial echocardiography was performed at baseline and 8 ± 5 days after aortic valve surgery to quantify LV dysfunction. Receiver operating characteristic analysis was performed to determine the diagnostic accuracy of native T1 mapping and extracellular volume for predicting postoperative LV ejection fraction decrease >-10% after aortic valve surgery.

Results

Native T1 was significantly increased in patients with a postoperatively decreased LVEF (n = 15) vs. patients with a preserved postoperative LV ejection fraction (n = 25) (i.e., 1,071 ± 67 ms vs. 1,019 ± 33 ms, p = .001). Extracellular volume was not significantly different between patients with preserved vs. decreased postoperative LV ejection fraction. With a cutoff-of value of 1,053 ms, native T1 yielded an area under the curve (AUC) of .820 (95% CI: .683-.958) for differentiating between patients with preserved vs. reduced LV ejection fraction with 70% sensitivity and 84% specificity.

Conclusion

Increased preoperative native T1 is associated with a significantly higher risk of systolic LV dysfunction early after aortic valve surgery in aortic regurgitation patients. Native T1 could be a promising tool to optimize the timing of aortic valve surgery in patients with aortic regurgitation to prevent early postoperative LV dysfunction.

Valvular Cardiomyopathy in Aortic Valve Regurgitation Correlates with Myocardial Fibrosis

Objective: At the tissue level, disruption of the extracellular matrix network leads to irreversible cardiac fibrosis, which contributes to myocardial dysfunction. At the myocyte level, downregulation of beta-adrenoceptors (beta-AR) reduces adaptation to increased workload. The aim of our study was to analyse the correlation between myocardial fibrosis and beta-AR sensitivity in patients with aortic valve (AV) disease. Methods: A total of 92 consecutive patients who underwent elective AV surgery between 2017-2019 were included in our study (51 with aortic regurgitation (AR-group); 41 with aortic stenosis (AS-group) and left ventricular (LV) biopsies were obtained intraoperatively. In vitro force contractility testing was performed by measuring beta-AR sensitivity (-log EC₅₀[ISO]). In parallel, a quantitative analysis of myocardial fibrosis burden was performed. Results: Mean age at the time of AV surgery was not statistically different in both groups (AR: 53.3 ± 15.3 years vs. AS: 58.7 ± 17.0 years; p = 0.116). The LV end-diastolic diameter was significantly enlarged in the AR-group when compared to the AS-group (59.4 ± 15.6 vs. 39.7 ± 21.2; p < 0.001). Analysis of beta-AR sensitivity (AR: -6.769 vs. AS: -6.659; p = 0.316) and myocardial fibrosis (AR: 8.9% vs. AS: 11.3%; p = 0.284) showed no significant differences between patients with AS and AR. There was no correlation between myocardial fibrosis and beta-AR sensitivity in the whole study cohort (R = 0.1987; p = 0.100) or in the AS-subgroup (R = 0.009; p = 0.960). However, significant correlation of fibrosis and beta-AR sensitivity was seen in AR-patients (R = 0.363; p = 0.023). Conclusion: More severe myocardial fibrosis was associated with reduced beta-AR sensitivity in patients presenting with AR but not with AS. Therefore, our results suggest that in patients with AR, cellular myocardial dysfunction is present and correlates with the extent of myocardial fibrosis in the myocardium.

ARNI or ARB Treats Residual Left Ventricular Remodelling after Surgery for Valvular Regurgitation: ReReRe study protocol

AIMS

Patients with persistent or de novo left ventricular (LV) dilation and/or reduced ejection fraction (EF) after correction for primary aortic (AR) or mitral (MR) regurgitation (i.e. residual LV remodelling) have not been well studied with regard to guideline-directed medical therapy after successful aetiology-reversing surgery. We aim to (i) compare the effectiveness of sacubitril/valsartan vs. valsartan in promoting LV reverse remodelling and (ii) explore the safety of medication withdrawal after LV recovery.

METHODS AND RESULTS

The ReReRe study is a multicentre, randomized, open-label, parallel trial that consists of two consecutive parts. A total of 371 patients with an LV end-diastolic diameter (LVEDD) > 60 mm or LVEF < 50%, assessed by transthoracic echocardiography (TTE) 7-14 days after valve surgery for significant AR or primary MR will be enrolled. The 1^st randomization into the sacubitril/valsartan or valsartan groups and structured follow-up (1, 3, 6, 9, and 12 months after randomization) will be conducted to observe the primary objective as the rate of complete recovery of LV remodelling (i.e. LVEDD < 55 mm and LVEF ≥ 60% by TTE at two consecutive visits). Those who have complete recovery of LV remodelling will be enrolled in Study Part 2; consequently, they will receive the 2^nd randomization into the medication withdrawal or maintenance group and 6-monthly visits for the observation of the primary objective as the rate of LV remodelling relapse (LVEDD > 60 mm or LVEF < 50%). The secondary objectives include the rate of composite clinical outcomes and the degree of change in 6-min walk distance and Kansas City Cardiomyopathy Questionnaire scores.

CONCLUSIONS

The ReReRe study will provide new evidence for the treatment of patients with residual LV remodelling after curable unloaded surgery, as well as the duration of treatment. The study results will fill the gap in identifying an appropriate medical therapy regimen for this group of patients and perhaps for those with reversible aetiologies of heart failure.

The usefulness of C-reactive protein to predict improving left ventricular function after aortic valve replacement in patients with aortic regurgitation

Background

We aimed to clarify the predictive factors for left ventricular (LV) function after aortic valve replacement (AVR) in patients with aortic regurgitation (AR).

Methods and results

Among 555 patients who underwent AVR at our institution from January 2015 to December 2020, we enrolled 44 patients for whom only AVR (or AVR + aortic replacement) was performed. We defined LV dysfunction under any of the following criteria: LV ejection fraction (LVEF) <50 %, LV diastolic dimension >65 mm, LV systolic dimension (LVDs) >50 mm, or LVDs/body surface area > 25 mm/m2. Multivariable logistic regression analysis revealed high natural logarithm (ln) C-reactive protein (CRP) and low LVEF in the pre-AVR period significantly associated with LV dysfunction after AVR (ln CRP: odds ratio [OR] 4.15, 95 % confidence interval [CI] 1.44-11.98, p < 0.01; LVEF: OR 0.79, 95%CI 0.65-0.97, p < 0.05). Receiver-operating characteristic analysis revealed an area under curve of CRP and LVEF in the pre-AVR period for LV dysfunction after AVR of 0.84 and 0.83, respectively. Upon dividing the patients into four groups according to cutoff values of CRP (0.13 mg/dL) and LVEF (50 %) in the pre-AVR period, no patients (0/19) had LV dysfunction in the low CRP (<0.13 mg/dL) and high LVEF (≥50 %) group, and all patients (5/5) in the high CRP (≥0.13 mg/dL) and low LVEF (<50 %) group had LV dysfunction after AVR.

Conclusion

High CRP level was significantly and independently associated with LV dysfunction after AVR. Combination of CRP and LVEF values might be useful for predicting improvement in LV function after AVR.