Transcatheter Interventions for Tricuspid Valve Disease: What to Do and Who to Do It On

Tricuspid valve disease, and particularly the management of severe tricuspid regurgitation (TR), has gained momentum in recent years. Although it is well known that this frequent condition is associated with poor clinical outcomes, these patients have been classically managed medically, leading to end-stage right ventricular heart failure. Moreover, late referral to surgery has contributed to a high rate of periprocedural complications and in-hospital surgical mortality. Thus, the development of a less invasive catheter-based therapy would be of high clinical relevance in this context. Several transcatheter tricuspid valve intervention (TTVI) devices have been developed in recent years. The particular characteristics of the tricuspid valve (large noncalcific annulus, presence of chief surrounding structures such as the conduction system or the right coronary artery) make multimodality imaging (eg, transesophageal echocardiography, computed tomography) key in the preprocedural assessment of TTVI. According to their mechanism of action and therapeutic target, TTVI includes transcatheter repair either with coaptation or annuloplasty systems, caval valve devices, and transcatheter tricuspid valve replacement. The initial TTVI experience showed that most procedures were well tolerated, with high procedural success and low in-hospital and early mortality. Also, most TTVI recipients improved their functional status and recent data suggest improved outcomes compared with medical management. However, the rate of significant residual TR after transcatheter tricuspid valve repair remains high and very scarce data exist on longer term (beyond 6-12 months) outcomes. The present review provides an overview regarding the framework of chronic TR and TTVI therapeutic options, and describes the updated current evidence in this challenging field.

Prognostic Implications of Increased Right Ventricular Wall Tension in Secondary Tricuspid Regurgitation

Secondary tricuspid regurgitation (TR) imposes a chronic volume overload on the right ventricle (RV) which can increase RV wall tension (RVWT). The aim of this study was to investigate the prognostic implications of increased RVWT in patients with significant secondary TR. A total of 1,142 patients with moderate-to-severe secondary TR were included. Based on the simplified Laplace-Young's law, RVWT was defined as the product between pulmonary artery systolic pressure (PASP) and RV base-to-apex length. The association between RVWT and risk of all-cause death was identified with spline curve analysis and patients were divided according to the cut-off of RVWT beyond which the hazard ratio (HR) and 95% confidence interval for all-cause mortality were above 1. Four hundred sixty-five (41%) patients had RVWT >3,300 mm Hg x mm and formed the group with increased RVWT. Patients with increased RVWT were more likely male, had more frequent heart failure symptoms and presented with more co-morbidities, larger RV and left ventricular (LV) dimensions, worse LV function, more severe secondary TR and higher PASP compared with patients with nonincreased RVWT. During a median follow-up of 51 (17 to 86) months, 586 (51%) patients died. The cumulative 5-year survival rate was significantly worse in patients with increased RVWT as compared with patients with nonincreased RVWT (38% vs 63% p <0.001). After correcting for potential confounders, increased RVWT retained an independent association with all-cause mortality (HR 1.555; 95% CI 1.268 to 1.907; p <0.001). In conclusion, increased RVWT is independently associated with worse prognosis and its evaluation may improve risk stratification in patients with significant secondary TR.

Left atrial strain as a pre-operative prognostic marker for patients with severe mitral regurgitation

BACKGROUND

In patients with severe mitral regurgitation (MR), additional echocardiographic indices could be helpful to optimize surgical timing before irreversible left heart myocardial dysfunction has occurred. We investigated the correlation of left atrial (LA) strain by speckle tracking echocardiography with prognosis after mitral surgery for severe MR, and its association with LA fibrosis.

METHOD

71 patients with primary severe MR undergoing pre-operative echocardiographic assessment were initially enrolled. Exclusion criteria were: other valvular disease>moderate, history of coronary artery disease, heart failure (HF), hypertrophic cardiomyopathy, left bundle branch block, previous pacemaker implantation, heart transplantation, poor acoustic window. The primary endpoint was the occurrence of composite events (HF and mortality); the secondary endpoint was post-operative functional capacity (NYHA and Borg CR10 class). LA fibrosis was assessed by atrial biopsy specimens in a subset of patients.

RESULTS

Of 65 eligible patients, the primary endpoint occurred in 30 patients (medium follow-up: 3.7 ± 1 years for event-group, 6.8 ± 1 years for non-event group). After Kaplan-Meier analysis, peak atrial longitudinal strain (PALS) provided good risk stratification (5-year event-free survival:90 ± 5% for PALS≥21% vs 30 ± 9% for PALS<21%, p < 0.0001); it was an independent and incremental predictor of outcome in four multivariate Cox adjusted models. There was also an association between PALS and the secondary endpoint (NYHA: r² = 0.11, p = 0.04; Borg CR10: r² = 0.10, p = 0.02) and an inverse correlation between PALS<21% and LA fibrosis (r² 0.80, fibrosis: 76.6 ± 20.7% vs 31.9 ± 20.8%;p < 0.0001).

CONCLUSIONS

Global PALS emerged as a reliable predictor of outcome and functional capacity for severe primary MR, and as a marker of LA fibrosis.