The Role of Invasive Hemodynamics in Guiding Contemporary Transcatheter Valvular Interventions

A Novel Hemodynamic Index Characterizing Mitral Regurgitation Undergoing Transcatheter Edge-to-Edge Repair: The MPF

Background

Hemodynamic impact of residual mitral regurgitation (MR) after transcatheter edge-to-edge repair (TEER) is not always univocally measured by transesophageal echocardiographic (TEE) assessment alone. When analyzing TEER procedure result, operators often encounter discrepancy between TEE guidance and invasive hemodynamic monitoring.

Objectives

This study sought to investigate the role of invasive hemodynamic monitoring during mitral valve TEER procedure on top of TEE guidance.

Methods

We analyzed 78 patients with moderate-to-severe or severe MR who underwent TEER. Mitral pulse pressure fraction (MPF) was extracted from intraprocedural continuous left atrial pressure monitoring. Twenty-three patients with the same grade of MR not undergoing TEER were included as a control group. At follow-up, clinical and functional status in the majority of patients undergoing TEER were reassessed by NYHA classification and the 12-item Kansas City Cardiomyopathy Questionnaire (KCCQ).

Results

TEER significantly reduced MR burden on both TEE guidance and invasive hemodynamic monitoring. Post-TEER MPF was significantly reduced compared to both pre-TEER setting (P < 0.001) and control group (P < 0.001). At follow-up, while MR reduction assessed by TEE was associated with an improved functional status in terms of the 12-item KCCQ but not of NYHA classification, a greater reduction in MPF was associated with a significant amelioration of both NYHA classification (P = 0.036) and 12-item KCCQ (P = 0.032).

Conclusions

MPF could provide an immediate estimate of the real hemodynamic impact of MR and a prompt prediction of the functional improvement after TEER.

Lymphatic morphology and function in chronic right heart failure due to secondary tricuspid valve regurgitation

BACKGROUND

In heart failure, the capacity of the lymphatic system dictates symptoms of circulatory congestion. This study aimed at describing structural and functional changes of the lymphatic system in patients with chronic right-sided heart failure.

METHODS

Individuals with long-standing severe tricuspid valve regurgitation and symptoms of heart failure were compared with age- gender- and weight-matched controls. Lymphatic structure and function were examined using non-contrast MR lymphangiography and near-infrared fluorescence imaging. Microvascular fluid dynamics and distribution were evaluated using strain gauge plethysmography and bio-impedance.

RESULTS

In total nine patients and nine controls were included. Lymphatic morphology was unchanged in cases compared to controls with similar thoracic duct diameters 3.1(2.1-3.5) mm vs. 2.0(1.8-2.4) mm (p-value = 0.11), similar lymphatic classifications (p-value 0.34), and an identical number of lymphatic vessels in the legs 6 ± 1 vs. 6 ± 3 vessels/field (p-value = 0.72). Lymphatic function was comparable with contraction frequencies of 0.5 ± 0.2 and 0.5 ± 0.3 /min (p-value = 0.52) and a maximal lymphatic pumping pressure of 60 ± 13 and 57 ± 12 mmHg (p-value = 0.59) for cases and controls respectively. Finally, microvascular capillary filtration, isovolumetric threshold, and fluid distribution were similar between groups (p-value≥0.16 for all comparisons).

CONCLUSION

In this small exploratory study, individuals with severe secondary tricuspid valve regurgitation and right-sided heart failure displayed a largely similar lymphatic anatomy and function. Thoracic duct diameter displayed a trend towards increased size in the patient group. We speculate that cases were indeed stable and optimally treated at the time of examination, and with a lymphatic system largely unaffected by any of the current or prior hemodynamic changes.

Moderate aortic stenosis: Navigating the uncharted

Aortic stenosis (AS) stands as the most common valvular heart disease in developed countries and is characterized by progressive narrowing of the aortic valve orifice resulting in elevated transvalvular flow resistance, left ventricular hypertrophy, and progressive increased risk of heart failure and sudden death. This narrative review explores clinical challenges and evolving perspectives in moderate AS, where discrepancies between aortic valve area and pressure gradient measurements may pose diagnostic and therapeutic quandaries. Transthoracic echocardiography is the first-line imaging modality for AS evaluation, yet cases of discordance may require the application of ancillary noninvasive diagnostic modalities. This review underscores the importance of accurate grading of AS severity, especially in low-gradient phenotypes, emphasizing the need for vigilant follow-up. Current clinical guidelines primarily recommend aortic valve replacement for severe AS, potentially overlooking latent risks in moderate disease stages. The noninvasive multimodality imaging approach-including echocardiography, cardiac magnetic resonance, computed tomography, and nuclear techniques-provides unique insights into adaptive and maladaptive cardiac remodeling in AS and offers a promising avenue to deliver precise indications and exact timing for intervention in moderate AS phenotypes and asymptomatic patients, potentially improving long-term outcomes. Nevertheless, what we may have gleaned from a large amount of observational data is still insufficient to build a robust framework for clinical decision-making in moderate AS. Future research will prioritize randomized clinical trials designed to weigh the benefits and risks of preemptive aortic valve replacement in the management of moderate AS, as directed by specific imaging and nonimaging biomarkers.

Pulmonary Vein Flow Morphology After Transcatheter Mitral Valve Edge-to-Edge Repair as Predictor of Survival

BACKGROUND

Data on the prognostic factors after mitral valve (MV) transcatheter edge-to-edge repair (TEER; MV-TEER) are limited. Pulsed-wave Doppler interrogation of pulmonary vein flow (PVF) is a convenient method to assess the hemodynamic burden of residual mitral regurgitation (MR), which could be of utility as a predictor of outcomes.

METHODS

Patients that underwent MV-TEER between May 2014 and December 2021 at our institution were evaluated. Pulmonary vein flow patterns post-MV-TEER were reviewed on the procedural transesophageal echocardiogram and classified as normal (systolic dominant or codominant) or abnormal (systolic blunting or reversal). The PVF pattern was correlated with all-cause mortality at follow-up.

RESULTS

Two-hundred sixty-five patients had diagnostic PVF post-MV-TEER, with 73 (27.5%) categorized as normal and 192 (72.5%) categorized as abnormal. Patients with abnormal PVF morphology were more likely to have atrial fibrillation (70% vs 42%, P < .001) and greater than moderate residual MR (16% vs 3%, P = .01) and had higher mean left atrial pressure (18.1 ± 5.0 vs 15.9 ± 4.2 mm Hg, P = .002) and left atrial V wave (26.6 ± 8.5 vs 21.4 ± 7.3 mm Hg, P < .001) postprocedure. In multivariable analysis, abnormal PVF morphology post-MV-TEER was independently associated with mortality at follow-up (hazard ratio = 1.70; 95% CI, 1.06-2.74; P = .03) after correction for end-stage renal disease, atrial fibrillation, and residual MR. Results were similar in subgroups of patients with moderate or less and those with mild or less residual MR.

CONCLUSIONS

Pulmonary vein flow morphology is a simple and objective tool to assess MR severity immediately post-MV-TEER and offers important prognostic information to optimize procedural results. Additional studies are needed to determine whether patients with abnormal PVF pattern post-MV-TEER would benefit from more intensive goal-directed medical therapy postprocedure.

Invasive assessment of aortic stenosis in contemporary practice

The authors review the current role of cardiac catheterization in the characterization of aortic stenosis, its main clinical applications, its pitfalls, and its additional value to the information provided by echocardiography. Discrepancies that may arise between these two modalities are discussed and further explained. Hemodynamic variables besides transvalvular pressure drop are described, and emphasis is given to an integrative approach to aortic stenosis assessment, that includes invasive and noninvasive evaluation.

Hemodynamics of transcatheter tricuspid valve replacement with Lux-Valve

Objective

Transcatheter tricuspid valve intervention (TTVI) has emerged as an alternative treatment option for high-risk and inoperable patients with symptomatic tricuspid regurgitation (TR). However, scarce data in hemodynamic profiles were available on TTVI. In this paper, we attempt to report the hemodynamic profiles of LuX-Valve.

Methods

30 patients from July 2020 to July 2021 were enrolled in this study. The patient was diagnosed with severe symptomatic TR. The clinical, invasive hemodynamic, and echocardiographic data were collected.

Results

The surgical success rate was 100%. The cardiac index and stroke volume increased sharply from 2.42(2.27, 2.85) and 47.8(43.6, 62.0) to 3.04 ± 0.63 and 57.2 ± 14.7, respectively. With the elimination of TR and the increase of forward blood flow of the tricuspid valve, the extravascular lung water [798.0 (673.0, 1147.0) vs. 850.3 ± 376.1, P < 0.01] increased subsequently. The peak right atrium pressure decreased after Lux-Valve implantation (21.0 ± 6.4 vs. 19.4 ± 6.5, P < 0.05). On the contrary, the nadir right atrium pressure increased [10.0(8.0, 15.0) vs. 12.0(10.0, 17.0), P < 0.01]. Notably, the right atrium pressure difference dropped sharply from 9.0(5.0, 13.0) to 5.0(4.0, 8.0) after Lux-Valve implantation. There was no significant change in the pulmonary artery pressure. The right atrium volume decreased from 128(83, 188) to 91(67, 167) mL at 1 month and 107(66,157) mL at 6 months. With the remolding of the right heart chamber, the tricuspid annulus diameter shrank significantly from 42.5 ± 5.6 to 36.6 ± 6.3 mm at 1 month and 36.0 (33.0, 38.0) at 6 months.

Conclusion

Invasive right atrium pressure may act as a potential candidate for TR evaluation and procedural guidance. Elimination of TR by LuX-Valve implantation improves the cardiac output and right atrium pressure and has no significant effect on the pulmonary artery pressure even with the increment of forward blood flow, suggesting the hemodynamic superiority of transcatheter tricuspid valve replacement but needs further study.

Transcatheter Coronary Sinus Interventions

The coronary sinus has become a popular route for an increasing number of innovative transcatheter interventions to treat coronary and structural heart diseases. However, interventional cardiologists have limited experience with the cardiac venous system and its highly variable anatomy. In this paper, we review the anatomy of the cardiac veins as it relates to transcatheter interventions. We also provide a contemporary overview of the emerging coronary sinus-based transcatheter therapies and their growing literature.