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.

Valve-in-valve procedure for bioprosthesis dysfunction in rheumatic patients: a new procedure for an old disease

Background

Bioprosthetic heart valve has a limited durability and lower long-term performance especially in rheumatic patients. The standard treatment for degenerated bioprosthesis involves redo open-heart surgery, which is associated with significant morbidity and mortality, particularly in high-risk patients. Minimally invasive procedures, as valve-in-valve (ViV) implantation, may offer an attractive therapy alternative.

Methods

The aim of this study was to evaluate the characteristics and short-term post-procedure data of rheumatic and non-rheumatic patients undergoing aortic, mitral or tricuspid ViV procedure.

Results

Single centre data-base analysis study, with prospective data collection, during the period of May 2015 to September 2020. Among 106 patients included, 69 had rheumatic etiology and 37 were non-rheumatic. Rheumatic patients had higher incidence of female sex (73.9% vs 43.2%, respectively; p=0.004) and atrial fibrillation (82.6% vs 45.9%, respectively; p<0.001). There were no statistical difference regarding number of previous surgeries (2 [3–1] vs 1 [2–1], respectively; p=0.103). There was a tendency towards higher 30-day mortality in rheumatic patients (21.7% vs 5.4%, respectively; p=0.057) and device success rate was low, but similar between groups (78.3% vs 72.0%, respectively; p=0.710). Transapical access rate was also higher in rheumatic group (92.6% vs 70.3%, respectively; p=0.008);

Conclusion

Rheumatic patients tend to have a higher mortality when undergoing ViV procedures, although not statistically significant. Rheumatic patients underwent a greater number of previous valve surgeries than reported in literature, and also had high rate of transapical ViV procedure, which may have contributed to higher 30-day mortality and a lower device success rate.

Funding Acknowledgement

Type of funding sources: None.

Rheumatic myocarditis: a poorly recognized etiology of left ventricular dysfunction in valvular heart disease patients

Background

Heart failure is present in about 10% of patients with acute rheumatic fever (RF), and several studies showed that cardiac decompensation in RF results primary from valvular disease, and not due to primary myocarditis. However, literature is scarce in this topic and a recent case series showed that recurrent RF could cause ventricular dysfunction even in the absence of valvular heart disease.

Purpose

To evaluate clinical, laboratory and echocardiographic profile of rheumatic fever patients with confirmed myocarditis diagnosis using Fluorine-18-fluorodeoxyglucose positron emission tomography (18F-FDG PET/CT) or Gallium-67 cardiac scintigraphy.

Methods

Clinical, laboratory and imaging characteristics of 25 consecutive patients with diagnosis of myocarditis, using 18F-FDG PET/CT or gallium-67 cardiac scintigraphy (Figure 1A and 1B, respectively), and RF reactivation according to revised Jones Criteria, were evaluated. Patients underwent 3 sequential echocardiograms: (1) baseline, (2) during myocarditis and (3) post- corticosteroid treatment, and were divided according to the presence (Group 1) or absence (Group 2) of reduced left ventricular ejection fraction (LVEF) during myocarditis episode.

Results

Median age was 42 (17–51) years, 64% had more than 40 years and 64% were women. Comparing patients in Group 1 (n=16) with Group 2 (n=9), there was no demographic, echocardiographic or laboratory difference between groups, except for NYHA III/IV heart failure (Group 1: 100.0% versus Group 2: 50.0%; p=0.012) and LVEF (30 [25–37] versus 56 [49–62] %, respectively; p<0.001), as expected. Group 1 patients had significant reduction of LVEF during carditis with further improvement after treatment (Figure 1C). There was no correlation between LVEF and valvular dysfunction during myocarditis. Of all patients, 19 (76%) underwent 18F-FDG PET/CT, with positive scan in 68.4% and 21 (84%) underwent Gallium-67 cardiac scintigraphy, with positive uptake in 95.2%, both with no difference between groups.

Conclusion

Myocarditis due to rheumatic fever reactivation can cause left ventricular dysfunction despite of valvular disease, and is reversible after corticosteroid treatment.

Funding Acknowledgement

Type of funding sources: None. Figure 1

P6483Predictors of contractile reserve on dobutamine stress echocardiography in patients with classical low-flow, low-gradient aortic stenosis

Background

There is a lack of information on factors that influence contractile reserve (CR) on dobutamine stress echocardiography (DSE) in patients with classical low-flow, low-gradient aortic stenosis (LFLG-AS).

Purpose

This study sought to evaluate the predictors of CR in patients with LFLG-AS.

Methods

Prospective study including 43 consecutive LFLG-AS patients (aortic valve area [AVA] ≤1.0 cm2, mean transaortic gradient <40 mmHg, left ventricular ejection fraction [LVEF] <50%) with true severe aortic stenosis. All patients underwent dobutamine stress echocardiography and T1-mapping cardiac magnetic resonance (CMR). CR was defined as an increase ≥20% in the left ventricular stroke volume at peak stress. Patients with pseudo-severe aortic stenosis were excluded.

Results

All of the patients in the study had degenerative aortic stenosis, with a median age of 67 [60–74] years, most of them being male (83.7%). A high prevalence of comorbidities was found, highlighted by diabetes (42%), hypertension (70%), atrial fibrillation (25%) and coronary artery disease (38%). Mean transaortic gradient was 25 [20–33] mmHg, AVA was 0.88 [0.68–0.95] cm2, LVEF was 35 [28–43]% and 32.6% had moderate/severe functional mitral regurgitation. CMR myocardium extracellular volume fraction (ECV) was 28.8 [26.3–33.0] %, indexed ECV was 35.4 [25.0–41.2] ml/m2, 32.6% had positive transmural delayed-enhancement images and 25.6% had positive mesocardial delayed-enhancement images. On DSE, 30 patients (69.7%) had CR and 13 patients (30.3%) had no CR. Global longitudinal strain was 10 [7–12] %, Δ indexed flow rate was 25 [3–38] ml/m2.seg and Δ mean gradient was 10 [3–16] mmHg. By multivariate analysis, moderate/severe functional mitral regurgitation (HR 0.122, 95% CI 0.020–0.759, p=0.024) and AVA (HR 0.606, 95% CI 0.396–0.925, p=0.020 [for each increase of 0.05 cm2]) were the only factors associated with CR. ECV, indexed ECV and positive transmural or mesocardial delayed-enhancement images were not associated with CR in the univariate analysis.

Conclusions

In our study, the absence of moderate/severe functional mitral regurgitation and AVA were predictors of CR on DSE in patients with LFLG-AS. As AVA was smaller in patients with CR, our finding contradicts the hypothesis that more severe aortic stenosis could also contribute to the lack of CR. Other possible factors that are surrogate of myocardium fibrosis, as ECV, indexed ECV and positive delayed-enhancement images, were not associated with the absence of CR.

Acknowledgement/Funding

FAPESP

Closed- and open-state models of human skeletal muscle sodium channel

Voltage-gated sodium channels play important roles in human physiology. However, their complexity hinders the understanding of their physiology and pathology at atomic level. We took advantage of the structural reports of similar channels obtained by cryo-EM (EeNav1.4, and NavPaS), and constructed models of human Nav1.4 channels at closed and open states. The open-state model is very similar to the recently published cryo-EM structure of hNav1.4. The comparison of both models shows shifts of the voltage sensors (VS) of DIII and DIV. The activated position of VS-DII in the closed model was demonstrated by Ts1 docking, thereby confirming the requirement that VS-DI, VS-DII and VS-DIII must be activated for the channel to open. The interactions observed with VS-DIII suggest a stepwise, yet fast, transition from resting to activated state. These models provide structural insights on the closed-open transition of the channel.

Atenolol blunts blood pressure increase during dynamic resistance exercise in hypertensives

AIMS

This study was conducted to determine whether atenolol was able to decrease BP level and mitigate BP increase during dynamic resistance exercise performed at three different intensities in hypertensives.

METHODS

Ten essential hypertensives (systolic/diastolic BP between 140/90 and 160/105mmHg) were blindly studied after 6 weeks of placebo and atenolol. In each phase, volunteers executed, in a random order, three protocols of knee-extension exercises to fatigue: (i) one set at 100% of 1RM; (ii) three sets at 80% of 1RM; and (iii) three sets at 40% of 1RM. Intra-arterial radial blood pressure was measured throughout the protocols.

RESULTS

Atenolol decreased systolic BP maximum values achieved during the three exercise protocols (100% = 186 ± 4 vs. 215 ± 7, 80% = 224 ± 7 vs. 247 ± 9 and 40% = 223 ± 7 vs. 252 ± 16mmHg, P < 0.05). Atenolol also mitigated an increase in systolic BP in the first set of exercises (100% =+38 ± 5 vs.+54 ± 9; 80% =+68 ± 11 vs. +84 ± 13 and 40% =+69 ± 7 vs.+84 ± 14, mmHg, P < 0.05). Atenolol decreased diastolic BP values and mitigated its increase during exercise performed at 100% of 1RM (126 ± 6 vs. 145 ± 6 and +41 ± 6 vs.+52 ± 6, mmHg, P < 0.05), but not at the other exercise intensities.

CONCLUSIONS

Atenolol was effective in both reducing systolic BP maximum values and mitigating BP increase during resistance exercise performed at different intensities in hypertensive subjects.