Long-term prognostic impact of pulmonary vascular resistance in patients with rheumatic mitral stenosis undergoing percutaneous mitral balloon valvuloplasty

Background

Pulmonary hypertension (PH) has a well-known impact on the prognosis of patients with rheumatic mitral stenosis (MS). Some patients can present pre-capillary PH, defined as a pulmonary vascular resistance (PVR) ≥3.0 woods, and there is few data regarding the prognostic value of invasive measures of PVR in this context.

Purpose

To assess the impact of PVR on the long-term outcomes of patients with rheumatic MS undergoing percutaneous mitral balloon valvuloplasty (PMBV).

Methods

Unicentric, retrospective study, including patients with rheumatic MS undergoing PMBV from 2016 to 2020. All patients underwent clinical and laboratorial evaluation, and transthoracic echocardiogram before and after the procedure. During PMBV, transesophageal echocardiogram and hemodynamic measures were performed. The composite endpoint included death, reintervention and persistent NYHA FC III–IV in long-term follow-up.

Results

58 patients were included with a median age of 50.5 [42–60.5] years and 82.8% were female. Most important comorbidities were hypertension (55.2%), previous valvular intervention (22.4%), diabetes (20.7%), atrial fibrillation (18%), previous stroke/transient ischemic attack (3.4%), coronary artery disease (1.7%). Median mitral valve area was 1.2 [0.9–1.3] cm2, mean transmitral gradient was 8 [6–12] mmHg and pulmonary artery systolic pressure (PASP) was 42 [35–51] mmHg. Pre-procedure hemodynamic right atrium pressure (RAP) was 8 [6–10] mmHg, pulmonary artery mean pressure (mPAP) was 26 [21–31] mmHg, pulmonary capillary pressure (PCP) was 18 [15–22] mmHg and PVR was 2.15 [1.5–3.46] mmHg/min. Thirty-five (60.3%) patients underwent 1 balloon dilation, 10 (17.2%) 2 dilations, 3 (5.3%) 3 dilations and 1 (1.7%) 4 dilations. Only 1 (1.7%) case need conversion to open surgery. Post-procedure hemodynamic Δ mPAP was 4 [1–8] mmHg, Δ PCP was 5 [2–7] mmHg and Δ PVR was 0.03 [−0.072–0.99] mmHg/min. Median follow-up was 32.9 [20.2–43] months. Need for reintervention (surgery or PMBV) was 6.9%, mortality during follow-up was 1.7% and the composite endpoint occurred in 13 (22.4%) patients. By univariate analysis, echocardiographic PSAP (HR: 1.069, 95% CI 1.010–1.130, p=0.021), RAP (HR: 1.267, 95% CI 1.028–1.562, p=0.027), Δ hemodynamic PASP (HR: 0.927, 95% CI 0.866–0.991, p=0.026) and moderate or severe tricuspid regurgitation (HR: 6.318, 95% CI 1.734–23.023, p=0.005) were associated with the composite endpoint. By multivariate analysis adjusted by RVP, RAP (HR: 1.626, 95% CI 1.005–2.630, p=0.047) was the only independent predictor of the composite endpoint. The RAP cutoff found through the Youden index was 9.5 mmhg (Figure 1).

Conclusion

In patients with severe MS undergoing PMBV, RAP measurement in cardiac catheterization was the only independent predictor of combined outcome of death, reintervention and persistent NYHA FC III–IV in long-term follow-up. PVR had no impact on long-term outcomes.

Funding Acknowledgement

Type of funding sources: None.

Impact of left ventricular fibrosis and longitudinal systolic strain on outcomes in low gradient aortic stenosis

Background

The clinical utility of comprehensive cardiac magnetic resonance (CMR) for the assessment of myocardial structure and function remains unknown in patients with low gradient (LG) aortic stenosis (AS).

Purpose

This study sought to compare CMR characteristics of myocardial structure and function according to different flow / gradient patterns of AS: classical low flow LG (LFLG); paradoxical LFLG; normal flow LG; and high gradient, and to evaluate their impact on the outcomes of these patients.

Methods

International multicentric prospective study included 147 patients with LG moderate to severe AS and 18 patients with high gradient severe AS who underwent comprehensive CMR evaluation of left ventricular global longitudinal strain (LVGLS), extracellular volume fraction (ECV), and late gadolinium enhancement (LGE).

Results

Patients with classical LFLG (n=90) had more LV adverse remodeling and impaired longitudinal function including higher ECV, and higher LGE and volume, and worst LVGLS, compared to other patterns of AS. Over a median follow-up of 2-years, 43 deaths and 48 composite outcomes of death or heart failure hospitalization occurred in LG AS patients. As LVGLS or ECV worsened, risks of adverse events also increased (per tertile of LVGLS: HR [95% CI] for mortality, 1.50 [1.02–2.20]; p=0.04; HR [95% CI] for composite outcome, 1.45 [1.01–2.09]; p<0.05) (per tertile of ECV: HR [95% CI] for mortality, 1.63 [1.07–2.49]; p=0.02; HR [95% CI] for composite outcome, 1.54 [1.02–2.33]; p=0.04). LGE presence was also associated with higher mortality (HR [95% CI], 2.27 [1.01–5.11]; p<0.05) and risk of the composite outcome (HR [95% CI], 3.00 [1.16–7.73]; p=0.02). The risk of all-cause death and of the composite outcome increased in proportion to the number of impaired components (i.e. LVGLS, ECV and LGE) (Figure) with and without adjustment for age, true severe AS, classical LFLG, and aortic valve replacement as a time-varying covariate.

Conclusions

In this international multicentric study of LG AS, comprehensive CMR assessment of myocardial structure and function provides independent prognostic value that is cumulative and incremental to clinical and echocardiographic characteristics.

Funding Acknowledgement

Type of funding sources: None.

Multimodality imaging and systemic biomarkers in classical low-flow low-gradient aortic stenosis: key findings for cardiac remodeling evaluation

Background

Elevated levels of troponin I (hsTnT) and B-type natriuretic peptide (BNP) have been related with poor prognosis in patients with LFLG-AS. Biomarkers are less expensive, more practical and more accessible than imaging tests, so their use can be an alternative to imaging in the evaluation of patients with LFLG-AS.

Purpose

The aim of the present study is to assess multimodality imaging findings according to systemic biomarkers (i.e. hsTnT and BNP) in Low-Flow, Low-Gradient Aortic Stenosis (LFLG-AS) and reduced left ventricular ejection fraction (LVEF) patients.

Methods

Prospective study with LFLG-AS patients (LVEF <50%, aortic valve area ≤1,0 cm2 and mean gradient <40 mmHg) that underwent hsTNnT, BNP, cardiac magnetic resonance (CMR) with T1 mapping and 2 dimensional echocardiogram (2DEcho). All patients also underwent dobutamine stress echocardiogram to define aortic stenosis severity. Patients were divided into 3 groups according to BNP and hsTnT levels: Group 1: BNP and hsTnT levels below median (BNP <395 pg/ml and TnI-Ultra <0.042 ng/ml); Group 2: BNP or hsTnT higher than median; and Group 3: both hsTnT and BNP higher than median.

Results

49 patients with LFLG-AS were included (Group 1: 17 patients, Group 2: 14 patients and Group 3: 18 patients). Clinical characteristics (including risk scores) were not able to stratify these groups. Patients with elevation of both biomarkers had lower valvuloarterial impedance (P=0.03), lower LVEF (P=0.02), less moderate/severe mitral (P=0.01) and tricuspid regurgitation (P<0.01) by 2DEcho. CMR identified a progressive increase (from Group 1 to 3) of right and left chamber volumes; reduction in right and left ejection fraction and a marked increase in myocardial fibrosis assessed by extracellular volume (ECV) and indexed extracellular volume (iECV) (Figure 1).

Conclusion

Higher levels of BNP and hsTnT in LFLG-AS patients were associated with worse multi-modality imaging parameters and can be a surrogate of cardiac remodeling.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): No funding

P929Predictors of renal function improvement in patients with chronic kidney disease undergoing TAVR

Background

Chronic kidney disease (CKD) is common among patients undergoing transcatheter aortic valve replacement (TAVR). The prognosis of CKD on TAVR outcomes has been previously documented. However, there is a paucity of data about predictors of renal function improvement and its clinical relevance.

Purpose

To determine predictors of renal function improvement after TAVR among patients with CKD.

Methods

Prospective study, analyzing 819 patients from 22 centers with symptomatic severe aortic stenosis included in the Brazilian TAVR Registry between 2008 and 2015. CKD was defined as estimated glomerular filtration rate (eGFR) <60mg/dL, and patients without CKD were excluded. Groups were divided according to variation of eGFR between baseline and 7 days after TAVR: improvement (increase >10% in eGFR) in 197 (34.1%) patients, worsening (decrease >10% in eGFR) in 203 (35.2%), and stable (neither criteria) in 177 (30.7%). Logistic regression analysis was used to identify predictors of renal function improvement. One-year outcomes were determined as Kaplan-Meier survival curves.

Results

CKD was present in 577 (70%) patients. The mean age was 81.9±6.8 years, 56.2% were male, 31.7% had diabetes and 74.5% had hypertension. The mean STS score was 10.6±7.9%, the mean EuroSCORE II were 21.8±15.2% and the preferable access site was transfemoral (93.4%). The mean eGFR was 37.3±12.5 ml/min in the improvement group (IG), 39.6±11.7 ml/min in the stable group (SG) and 40.2±12.3 ml/min in the worsening group (WG), with significant statistical difference between IG and WG (p=0.044). There was no difference related to contrast midia volume between the 3 groups. In the multivariate analysis, coronary artery disease (OR: 0.69; 95% CI 0.48–0.98; p=0.039) and baseline eGFR (OR: 0.98; 95% CI 0.97–1.00; p=0.039) were associated with improvement in renal function. There was no significant difference in 1-year all-cause mortality between IG and SG (15.4 vs 9.5%, log rank p=0.141) (Figure 1A). However, the WG had higher mortality compared with the IG (29.3 vs 15.4%, log rank p<0,001) (Figure 1B).

Figure 1

Conclusion

Improvement in renal function after TAVR was frequently found among patients with CKD. The absence of coronary artery disease and lower baseline eGFR were independent predictors of improvement in renal function. Although the IG had lower 1-year all-cause mortality compared to WG, no difference were observed related to SG.

Acknowledgement/Funding

SBHCI