P924 Benefits of bariatric surgery on subclinical myocardial function using global longitudinal strain in severely obese individuals with and without diabetes

Purpose

To evaluate changes in subclinical LV myocardial function following bariatric surgery in obese individuals with and without diabetes.

Methods

Thirty-eight severely obese individuals [body mass index (BMI) >35kg/m2] with preserved LV ejection fraction (≥ 50%) who underwent bariatric surgery (Surgery group) (BMI 48 ± 7 kg/m2), 19 obese individuals managed conservatively (Cons. group) (BMI 47 ± 9 kg/m2), and 18 age and sex-matched non-obese controls (Non-obese group) were included. Echocardiography with GLS measurements was performed at the beginning of the study and at 6 months. Abnormal myocardial function was defined as a GLS >-17%.

Results

Mean age of obese patients was 42 ± 11, BMI 48 ± 8 kg/m2, and 82% were female. The percentage of total weight loss at 6 months after bariatric surgery (Surgery group) was 26.3 ± 5.2%. Body weight remains unchanged at 6 months in the Cons. group. Proportions of hypertension (61 vs. 30%, P = 0.0005), dyslipidemia (42 vs. 5%, P = 0.0001) and type 2 diabetes (40 vs. 13%, P = 0.002) were reduced in the Surgery group. At the beginning, severely obese patients (Surgery group) displayed subclinical myocardial dysfunction vs. non-obese controls (LV GLS, -17.3 ± 2.5 vs. -19.6 ± 1.7%, P = 0.003). Six months after bariatric surgery, the subclinical myocardial function was comparable between both groups (LV GLS, -19.2 ± 2.1 vs. -19.6 ± 1.7%, P = NS). 22 severely obese individuals (58%) in the Surgery group showed abnormal GLS, which normalized in 82% after bariatric surgery (P = 0.0001). On the contrary, half of severely obese individuals managed conservatively (n = 10, 53%) worsened their GLS during the follow-up (P = 0.002). Remission of type 2 diabetes 6 months after bariatric surgery was associated with improvement in GLS (-17.5 ± 2.6 vs. -18.6± 1.8%), whereas obese individuals with type 2 diabetes managed conservatively showed a worsening in their subclinical myocardial function during the follow-up (-18.0 ± 2.4 vs. -17.4 ± 1.7%).

Conclusions

A great proportion of severely obese individuals with preserved LV ejection fraction have subclinical myocardial dysfunction. Bariatric surgery in obese individuals was associated with significant improvements in the metabolic profile and in subclinical myocardial function.

P914Balloon aortic valve valvuloplasty as palliative therapy in severe aortic valve stenosis: 10 years experience in a single centre

Background

Improved technology together with greater operator experience has led to refinement of balloon aortic valve valvuloplasty (BAV) in recent years. It may provide a palliative treatment option in high-risk patients, highly symptomatic, for whom no other invasive therapy is available. However, there has not been universal adoption of BAV as a standalone therapy.

Methods

A retrospective analysis of ten years of practice of BAV as palliative strategy in patient with symptomatic aortic stenosis between March 2008 and June 2018 was performed. Demographic, clinical, procedural, and follow-up data on all patients were collected.

Results

A total of 152 patients (95 women, 63%) with a mean age of 85±6 years underwent BAV. All patients had severe aortic stenosis, were considered not suitable to aortic valve replacement nor Trans-catheter aortic valve implantation (TAVI) for appreciable comorbidity (STS score 9±5) and had severe symptoms mainly of heart failure which required medical attention. A statistically significant decrease in trans-valvular gradient was observed (peak to peak gradient before BAV 52±22 mmHg, after BAV 29±16 mmHg, delta gradient 24±14 mmHg; p<0.0001). Only one patient, who undergone BAV because of cardiogenic shock, died during the procedure. Considering the high-risk population, intra-hospital mortality was low (7 patients died, 4%). Mortality at 1-year follow-up was 43% and survival free from new hospitalization for heart failure was 63% at 1-year follow-up and 53% at 2 years follow-up. 19 patients (13%) required repeated BAV during follow-up.

Conclusion

BAV as a palliative procedure in high-risk patients who are highly symptomatic, has a low operative mortality in our experience. BAV is associated with a significant reduction in aortic valve gradient and is valuable since half of the patients were alive without re-hospitalizations for heart failure at 2 years follow-up.

Acknowledgement/Funding

None

6097Aminoterminal proB-type natriuretic peptide: a key parameter to optimise therapeutic management of low-flow, low-gradient aortic stenosis

Background

B-type natriuretic peptide (BNP) and aminoterminal-proBNP (NT-proBNP) are well established surrogates of LV function impairment. However, data are scarce regarding their prognostic value to risk-stratify patients with classical low-flow, low-gradient aortic stenosis (LFLG-AS, with low left ventricular [LV] ejection fraction).

Methods

The TOPAS study is a prospective observational cohort of 240 patients with aortic valve area <0.6 cm2/m2, mean gradient<40 mmHg and LVEF<50%. True severe AS was adjudicated using flow independent grading schemes.

Results

BNP significantly predicted one-year (area under the receiver operating-characteristic curve [AUC]) 0.62±0.04, p=0.026) but not three-year mortality. After adjustment for the severity of AS, initial treatment (aortic valve replacement [AVR] vs. conservative management [ConsRx]), age, sex and the EuroSCORE (Model#1), BNP-ratio>550 pg/ml had a trend to predict time to death (HR=2.14 [1.00–4.58], p=0.05). In contrast, NT-proBNP ratio significantly predicted both one and three-year mortality (AUC=0.67±0.04 and 0.66±0.05, both p=0.001), and independently predicted time to death (HR=1.39 per 1 unit of Log transformed NT-proBNP [1.11–1.74], p=0.004). In a head-to-head comparison (108 patients with both biomarkers), the AUCs to predict one and thre-year mortality were significantly higher with NT-proBNP versus BNP (p<0.009). NT-proBNP but not BNP independently predicted mortality and significantly improved Model#1 (Likelihood ratio test Chi2=15.95, p<0.001). The category-free net reclassification index of NT-proBNP was 0.71 (p=0.008) versus 0.38 (p=0.15) for BNP. Furthermore, there was a marked survival benefit associated with AVR in patients with NT-proBNP ≥1700 pg/ml (adjusted hazard ratio (aHR) associated to AVR vs conservative management=0.52 [0.31–0.85], p=0.009), while those<1700 pg/ml had excellent one-year survival under ConsRx (only one death [4.5±4.4%] at one year as compared to 23 [37±6.2%] for ConsRx-NTproBNP>1700, aHR=0.11 [0.01–0.83], p=0.033). The survival benefit associated with AVR interacted with NT-proBNP (p<0.001) but not with true or pseudosevere AS (p=0.53 for interaction), suggesting that NT-proBNP might identify moderate AS patients but sufficiently severe valvulo-ventricular disease to justify AVR.

Survival according to NT-proBNP and AVR

Conclusion

NT-proBNP appears to be an excellent biomarker for the clinical purpose of risk-stratifying classical LFLG-AS. A threshold of 1700 pg/ml i.e. close to the diagnostic threshold for heart failure in acute dyspnea, was a strong independent determinant of the survival benefit associated with aortic valve replacement. Our findings suggest that NT-proBNP should be preferred over BNP.

Acknowledgement/Funding

Canadian Institute of Health Research

6099Impact of aortic valve replacement on outcomes of patients with low-flow, low-gradient moderate aortic stenosis

Background

Aortic valve replacement (AVR) is recommended for patients with low-flow, low-gradient (LFLG) and true-severe aortic stenosis (TSAS). However, there is very few data on the potential benefit of AVR in patients with LFLG pseudo-severe (i.e. moderate) AS (PSAS).

Methods

Consecutive patients with aortic valve area ≤0.6 cm2/m2, mean gradient <40 mmHg were prospectively recruited in a multicenter observational cohort study. The patients were categorized in TSAS vs. PSAS using previously reported thresholds of flow-independent parameters of AS severity (projected valve area at normal flow rate ≤1.0 cm2 and/or aortic valve calcium score by CT >1200 AU in women and >2000 AU in men). To account for between-treatment-group differences, inverse probability-of-treatment weighting was combined to Cox proportional hazards regression.

Results

Among the 430 patients included in this study, 297 (69%) were classified as TSAS and 274 (57%) underwent AVR. Of note, 21% of the patients treated by AVR were classified as PSAS. In patients managed conservatively (ConsRx), 52% had PSAS and 48% TSAS. During a median follow-up of 28 months [8–60], 198 patients died. The adjusted weighted hazard ratio (awHR) of death associated with AVR as compared to ConsRx was 0.42 [0.24–0.73] (p<0.0001, Figure1-Panel-A). This survival benefit associated with AVR was observed not only in patients with TSAS but also in those with PSAS (awHR: 0.29 [0.12–0.70]; p=0.006, Figure1-Panel-B).

Figure 1

Conclusion

The results of this study suggest that AVR is associated with a survival benefit not only in LFLG patients with TSAS but also in those with PSAS. Randomized trials are needed to confirm the benefit of AVR in patients with moderate AS and depressed LV systolic function.

Acknowledgement/Funding

Canadian Institute of Health Research

1337Myocardial extracellular volume in patients with aortic stenosis undergoing valve intervention - A multicentre T1 mapping study

Background

The development of myocardial fibrosis is a key mechanism in the transition from compensated hypertrophy to heart failure in aortic stenosis (AS). Focal and diffuse fibrosis can be quantified using cardiac magnetic resonance (CMR) imaging late gadolinium-enhanced (LGE) and T1 mapping techniques.

Purpose

To assess T1 mapping measures of fibrosis in patients with severe AS referred for aortic valve intervention, and determine their associations with clinical characteristics, disease severity and long-term clinical outcome.

Methods

In this international prospective cohort study, patients with severe AS underwent contrast enhanced CMR with T1 mapping and LGE prior to aortic valve intervention. Image analysis was performed by a single core laboratory and the extracellular volume fraction [ECV%] calculated from T1 mapping images. The presence of LGE was determined visually and quantified using the full-width-at-half-maximum technique.

Results

Four-hundred and forty patients (70±10 years, 59% male) from ten international centres were enrolled. Aortic valve intervention was performed 15 [4 to 58] days following CMR. Within a follow-up of 3.8 [2.8 to 4.6] years, 52 patients died.

ECV% (mean 27.7±3.6%) correlated with increasing age, Society of Thoracic Surgeons Predicted Risk of Mortality score, known coronary artery disease, lower peak aortic-jet velocity, larger left ventricular (LV) mass, lower LV ejection fraction, and presence of LGE (P<0.05 for all). Following adjustment for all demographic and clinical variables, ECV% remained associated with age (P=0.028), LV ejection fraction (P<0.001) and presence of LGE (P=0.035).

Univariable predictors of all-cause mortality included age, male sex, impaired LV ejection fraction and presence of LGE (all P<0.05). A progressive increase in all-cause mortality was seen across tertiles of ECV% (17.3, 31.6 and 52.7 deaths per 1000 patient-years; log-rank test, P=0.009). ECV% was independently associated with all-cause mortality following adjustment for age, sex, impaired LV ejection fraction and presence of LGE (HR per unit increase in ECV: 1.10, 95%, (1.02–1.19), P=0.013).

ECV440 abstract iamge

Conclusion

In patients with severe aortic stenosis scheduled for aortic valve intervention, extracellular volume-based T1 mapping correlates with LV decompensation. ECV% is a strong independent predictor of late all-cause mortality and is a potential therapeutic target.

Autotaxin interacts with lipoprotein(a) and oxidized phospholipids in predicting the risk of calcific aortic valve stenosis in patients with coronary artery disease

BACKGROUND

Studies have shown that lipoprotein(a) [Lp(a)], an important carrier of oxidized phospholipids, is causally related to calcific aortic valve stenosis (CAVS). Recently, we found that Lp(a) mediates the development of CAVS through autotaxin (ATX).

OBJECTIVE

To determine the predictive value of circulating ATX mass and activity for CAVS.

METHODS

We performed a case-control study in 300 patients with coronary artery disease (CAD). Patients with CAVS plus CAD (cases, n = 150) were age- and gender-matched (1 : 1) to patients with CAD without aortic valve disease (controls, n = 150). ATX mass and enzymatic activity and levels of Lp(a) and oxidized phospholipids on apolipoprotein B-100 (OxPL-apoB) were determined in fasting plasma samples.

RESULTS

Compared to patients with CAD alone, ATX mass (P < 0.0001), ATX activity (P = 0.05), Lp(a) (P = 0.003) and OxPL-apoB (P < 0.0001) levels were elevated in those with CAVS. After adjustment, we found that ATX mass (OR 1.06, 95% CI 1.03-1.10 per 10 ng mL^-1 , P = 0.001) and ATX activity (OR 1.57, 95% CI 1.14-2.17 per 10 RFU min^-1 , P = 0.005) were independently associated with CAVS. ATX activity interacted with Lp(a) (P = 0.004) and OxPL-apoB (P = 0.001) on CAVS risk. After adjustment, compared to patients with low ATX activity (dichotomized at the median value) and low Lp(a) (<50 mg dL^-1 ) or OxPL-apoB (<2.02 nmol L^-1 , median) levels (referent), patients with both higher ATX activity (≥84 RFU min^-1 ) and Lp(a) (≥50 mg dL^-1 ) (OR 3.46, 95% CI 1.40-8.58, P = 0.007) or OxPL-apoB (≥2.02 nmol L^-1 , median) (OR 5.48, 95% CI 2.45-12.27, P < 0.0001) had an elevated risk of CAVS.

CONCLUSION

Autotaxin is a novel and independent predictor of CAVS in patients with CAD.

Comparison between transcatheter and surgical prosthetic valve implantation in patients with severe aortic stenosis and reduced left ventricular ejection fraction

BACKGROUND

Patients with severe aortic stenosis and reduced left ventricular ejection fraction (LVEF) have a poor prognosis with conservative therapy but a high operative mortality when treated surgically. Recently, transcatheter aortic valve implantation (TAVI) has emerged as an alternative to surgical aortic valve replacement (SAVR) for patients considered at high or prohibitive operative risk. The objective of this study was to compare TAVI and SAVR with respect to postoperative recovery of LVEF in patients with severe aortic stenosis and reduced LV systolic function.

METHODS AND RESULTS

Echocardiographic data were prospectively collected before and after the procedure in 200 patients undergoing SAVR and 83 patients undergoing TAVI for severe aortic stenosis (aortic valve area ≤1 cm(2)) with reduced LV systolic function (LVEF ≤50%). TAVI patients were significantly older (81±8 versus 70±10 years; P<0.0001) and had more comorbidities compared with SAVR patients. Despite similar baseline LVEF (34±11% versus 34±10%), TAVI patients had better recovery of LVEF compared with SAVR patients (ΔLVEF, 14±15% versus 7±11%; P=0.005). At the 1-year follow-up, 58% of TAVI patients had a normalization of LVEF (>50%) as opposed to 20% in the SAVR group. On multivariable analysis, female gender (P=0.004), lower LVEF at baseline (P=0.005), absence of atrial fibrillation (P=0.01), TAVI (P=0.007), and larger increase in aortic valve area after the procedure (P=0.01) were independently associated with better recovery of LVEF.

CONCLUSION

In patients with severe aortic stenosis and depressed LV systolic function, TAVI is associated with better LVEF recovery compared with SAVR. TAVI may provide an interesting alternative to SAVR in patients with depressed LV systolic function considered at high surgical risk.