Implications of Elevated Pulmonary Artery Pressure for Transcatheter Mitral Repair: Time for Comprehensive Hemodynamic Investigation

Reappraisal of the Concept and Implications of Pulmonary Hypertension in Degenerative Mitral Regurgitation

BACKGROUND

European and U.S. clinical guidelines diverge regarding pulmonary hypertension (PHTN) in degenerative mitral regurgitation (DMR). Gaps in knowledge underpinning these divergences affect risk assessment and management recommendations attached to systolic pulmonary pressure (SPAP) in DMR.

OBJECTIVES

This study sought to define PHTN links to DMR severity, prognostic thresholds, and independent outcome impact in a large quantitative DMR registry.

METHODS

This study gathered a large multicentric registry of consecutive patients with isolated moderate-to-severe DMR, with DMR and SPAP quantified prospectively at diagnosis.

RESULTS

In 3,712 patients (67 ± 15 years, 36% women) with ≥ moderate-to-severe DMR, effective regurgitant orifice (ERO) was 0.42 ± 0.19 cm2, regurgitant volume 66 ± 327 mL/beat and SPAP 41 ± 16 mm Hg. Spline-curve analysis showed excess mortality under medical management emerging around SPAP 35 mm Hg and doubling around SPAP 50 mm Hg. Accordingly, severe pulmonary hypertension (sPHTN) (SPAP ≥50 mm Hg) was detected in 916 patients, moderate pulmonary hypertension (mPHTN) (SPAP 35-49 mm Hg) in 1,128, and no-PHTN (SPAP <35 mm Hg) in 1,668. Whereas SPAP was strongly associated with DMR-ERO, nevertheless excess mortality with sPHTN (adjusted HR: 1.65; 95% CI: 1.24-2.20) and mPHTN (adjusted HR: 1.44; 95% CI: 1.11-1.85; both P ≤ 0.005) was observed independently of ERO and all baseline characteristics and in all patient subsets. Nested models demonstrated incremental prognostic value of mPHTN and sPHTN (all P < 0.0001). Despite higher operative risk with mPHTN and sPHTN, DMR surgical correction was followed by higher survival in all PHTN ranges with strong survival benefit of early surgery (<3 months). Postoperatively, excess mortality was abolished (P ≥ 0.30) in mPHTN, but only abated in sPHTN.

CONCLUSIONS

This large international registry, with prospectively quantified DMR and SPAP, demonstrates a Doppler-defined PHTN impact on mortality, independent of DMR severity. Crucially, it defines objectively the new and frequent mPHTN range, independently linked to excess mortality under medical management, which is abolished by DMR correction. Thus, at DMR diagnosis, Doppler-SPAP measurement defining these new PHTN ranges, is crucial to guiding DMR management.

The evolution of technical prerequisites and local boundary conditions for optimization of mitral valve interventions-Emphasis on skills development and institutional risk performance

This viewpoint report describes how the evolution of transcatheter mitral valve intervention (TMVI) is influenced by lessons learned from three evolutionary tracks: (1) the development of treatment from mitral valve surgery (MVS) to transcutaneous procedures; (2) the evolution of biomedical engineering for research and development resulting in predictable and safe clinical use; (3) the adaptation to local conditions, impact of transcatheter aortic valve replacement (TAVR) experience and creation of infrastructure for skills development and risk management. Thanks to developments in computer science and biostatistics, an increasing number of reports regarding clinical safety and effectiveness is generated. A full toolbox of techniques, devices and support technology is now available, especially in surgery. There is no doubt that the injury associated with a minimally invasive access reduces perioperative risks, but it may affect the effectiveness of the treatment due to incomplete correction. Based on literature, solutions and performance standards are formulated with an emphasis in technology and positive outcome. Despite references to Heart Team decision making, boundary conditions such as hospital infrastructure, caseload, skills training and perioperative risk management remain underexposed. The role of Biomedical Engineering is exclusively defined by the Research and Development (R&D) cycle including the impact of human factor engineering (HFE). Feasibility studies generate estimations of strengths and safety limitations. Usability testing reveals user friendliness and safety margins of clinical use. Apart from a certification requirement, this information should have an impact on the definition of necessary skills levels and consequent required training. Physicians Preference Testing (PPT) and use of a biosimulator are recommended. The example of the interaction between two Amsterdam heart centers describes the evolution of a professional ecosystem that can facilitate innovation. Adaptation to local conditions in terms of infrastructure, referrals and reimbursement, appears essential for the evolution of a complete mitral valve disease management program. Efficacy of institutional risk management performance (IRMP) and sufficient team skills should be embedded in an appropriate infrastructure that enables scale and offers complete and safe solutions for mitral valve disease. The longstanding evolution of mitral valve therapies is the result of working devices embedded in an ecosystem focused on developing skills and effective risk management actions.

Prognostic Value of Pulmonary Hypertension, Right Ventricular Function and Tricuspid Regurgitation on Mortality After Transcatheter Mitral Valve Repair: A Systematic Review and Meta-Analysis

BACKGROUND

Pulmonary hypertension (PH), right ventricular (RV) dysfunction, and tricuspid regurgitation (TR) are commonly present in patients with mitral regurgitation (MR) and known to impair prognosis. This systematic review and meta-analysis aimed to determine the prognostic value of PH, RV function, and TR on mortality after transcatheter mitral valve repair (TMVR).

METHODS

A systematic search was performed to identify studies investigating PH, RV function, or TR in patients who underwent TMVR. Studies were included for pooled analysis if hazard ratios (HR) for all-cause mortality were given.

RESULTS

A total of 8,672 patients from 21 selected studies were included (PH, 11 studies; RV function, nine studies; TR, 10 studies). Mean follow-up was 2.7±1.6 years. The HRs and 95% CIs for all-cause mortality of PH (dichotomised: HR 1.70, 95% CI 1.00-2.87; per 10 mmHg increase in systolic PAP: HR 1.17, 95% CI 1.07-1.29), RV function (dichotomised: HR 1.86, 95% CI 1.45-2.38; per 5 mm decrease in TAPSE: HR 1.18, 95% CI 0.97-1.43) and TR (HR 1.51, 95% CI 1.28-1.79) indicated a significant association.

CONCLUSION

Prognosis after TMVR is worse in patients with significant MR when concomitant PH, RV dysfunction, or TR are present. Careful assessment of these parameters should therefore precede clinical decision-making for TMVR. The current results encourage investigation into whether (1) intervention at an earlier stage of MR reduces incidence of PH, RV dysfunction, and TR; and (2) transcatheter treatment of concomitant TR can improve clinical outcome and prognosis for these patients.