STREI: a new index of right heart function in isolated severe tricuspid regurgitation by speckle-tracking echocardiography

AIMS

Right ventricular (RV) performance determines clinical management in severe tricuspid regurgitation (TR). Right atrial (RA) function complements RV assessment in TR. This study aimed to design a novel index by speckle-tracking echocardiography (STREI index) integrating RA and RV strain information and to evaluate the clinical utility of combining RV and RA strain for prediction of cardiovascular (CV) outcomes.

METHODS AND RESULTS

Consecutive patients with at least (≥) severe TR evaluated in the Heart Valve Clinic (n = 300) were prospectively included. An additional independent TR cohort was included for external validation (n = 50). STREI index was developed with the formula: [2 ∗ RV-free wall longitudinal strain (RV-FWLS)] + reservoir RA strain (RASr). The composite endpoint included hospital admission due to heart failure and all-cause mortality. A total of 176 patients with ≥severe TR were finally included. STREI index identified a higher percentage of patients with RV dysfunction compared with conventional parameters. After a median follow-up of 2.2 years (interquartile range: 12-41 months), a total of 38% reached the composite endpoint. STREI values were predictors of outcomes independently of TR severity and RV dimensions. The combination of prognostic cut-off values of RASr (<10%) and RV-FWLS (>-20%) (STREI stratification) stratified four different groups of risk independently of TR severity, RV dimensions, and clinical status (adj HR per stratum 1.89 (1.4-2.34), P < 0.001). Pre-defined cut-off values achieved similar prognostic performance in the validation cohort (n = 50).

CONCLUSION

STREI index is a novel parameter of RV performance that independently predicts CV events. The combination of RA and RV strain stratifies better patients' risk, reflecting a broader effect of TR on right heart chambers.

MCJ: A mitochondrial target for cardiac intervention in pulmonary hypertension

Pulmonary hypertension (PH) can affect both pulmonary arterial tree and cardiac function, often leading to right heart failure and death. Despite the urgency, the lack of understanding has limited the development of effective cardiac therapeutic strategies. Our research reveals that MCJ modulates mitochondrial response to chronic hypoxia. MCJ levels elevate under hypoxic conditions, as in lungs of patients affected by COPD, mice exposed to hypoxia, and myocardium from pigs subjected to right ventricular (RV) overload. The absence of MCJ preserves RV function, safeguarding against both cardiac and lung remodeling induced by chronic hypoxia. Cardiac-specific silencing is enough to protect against cardiac dysfunction despite the adverse pulmonary remodeling. Mechanistically, the absence of MCJ triggers a protective preconditioning state mediated by the ROS/mTOR/HIF-1α axis. As a result, it preserves RV systolic function following hypoxia exposure. These discoveries provide a potential avenue to alleviate chronic hypoxia-induced PH, highlighting MCJ as a promising target against this condition.

Clinical utility and prognostic value of right atrial function in severe tricuspid regurgitation: one more piece of the puzzle

AIMS

The optimal management of severe tricuspid regurgitation (TR) remains controversial. While right ventricular systolic function is an established prognostic marker of outcomes, the potential role of right atrial (RA) function is unknown. This study aimed to describe RA function by 2D speckle-tracking echocardiography (STE) in at least severe TR and to evaluate its potential association with cardiovascular outcomes.

METHODS AND RESULTS

Consecutive patients with at least (≥) severe TR (severe, massive, or torrential TR) evaluated in the Heart Valve Clinic following a comprehensive clinical protocol were included. Consecutive control subjects and patients with permanent isolated atrial fibrillation (AF) were included for comparison (control and AF group, respectively). RA function was measured with 2D-STE and two components of RA function were calculated: reservoir (RASr) and contractile (RASct) strain (AutoStrain, Philips Medical Systems the EPIQ system). A combined endpoint of hospital admission due to heart failure (HF) or all-cause mortality was defined. Patients with ≥ severe TR (n = 140) showed lower RASr compared with controls (n = 20) and with the AF group (n = 20) (P < 0.001). Atrial TR showed lower RASr compared with other aetiologies of TR (P < 0.001). After a median follow-up of 2.2 years (IQR: 12-41 months), RASr remained an independent predictor of mortality and HF. A cut-off value of RASr of <9.4% held the best accuracy to predict outcomes.

CONCLUSION

RA function by 2D-STE independently predicts mortality and HF hospitalizations in patients with ≥ severe TR.

Prognostic Impact of Right Ventricular Strain in Isolated Severe Tricuspid Regurgitation

BACKGROUND

Right ventricular (RV) systolic function is an established marker of outcomes in patients with severe tricuspid regurgitation (TR). Timely detection of RV dysfunction using conventional two-dimensional echocardiography is challenging. RV strain has emerged as an accurate and sensitive tool for the evaluation of RV function, with the capability to detect subclinical RV dysfunction. The aim of this study was to evaluate the prognostic value of RV strain parameters in early stages of severe TR.

METHODS

Consecutive patients with at least severe TR (severe, massive, or torrential) and the absence of a formal indication for tricuspid valve intervention in secondary TR evaluated in the Heart Valve Clinic were prospectively included. RV systolic function was measured using conventional echocardiographic indices (RV fractional area change, tricuspid annular plane systolic excursion, and Doppler tissue imaging S wave [S']) and speckle-tracking echocardiography-derived automatic peak global longitudinal strain and free wall longitudinal strain (FWLS) using an automated two-dimensional strain analytic software. A combined end point of hospital admission due to heart failure or all-cause mortality was defined.

RESULTS

A total of 266 patients were enrolled in the study, and 151 were ultimately included. Strain parameters detected a higher percentage of abnormal RV values compared with conventional indices. During a median follow-up period of 26 months (interquartile range, 13-42 months), 35% of the patients reached the combined end point. Cumulative event-free survival was significantly worse in patients with impaired RV global longitudinal strain and RV FWLS. Conventional indices of RV systolic function were not associated with outcomes (P > .05 for all). On multivariate analysis, RV FWLS was independently associated with mortality and heart failure (adjusted hazard ratio for abnormal RV FWLS, 5.90; 95% CI, 3.17-10.99; P < .001).

CONCLUSION

In early stages of severe TR, RV FWLS is more frequently impaired compared with conventional indices of RV function. Among all parameters, RV FWLS is the strongest predictor of mortality and heart failure, independent of additional prognostic markers.

Outcomes in aortic and mitral valve replacement with intervalvular fibrous body reconstruction

BACKGROUND

Surgery for intervalvular fibrous body reconstruction in aortic and mitral valve replacement is a complex operation, although mandatory in some circumstances. The long-term result of this operation remains unknown. The objective of this study was to analyze the outcomes of this technique.

METHODS

A descriptive and retrospective study was carried out to analyze operative morbidity and mortality in fibrous body reconstruction with the "David technique" and to evaluate the midterm and long-term results regarding durability and survival.

RESULTS

A total of 40 consecutive patients underwent the David technique between 1997 and 2014. The mean age was 58 ± 15 years and 62.5% were male. The indications were active endocarditis with paravalvular and fibrous body abscesses in 26 patients (group A) and massive calcification of the intervalvular fibrous body in 14 patients (group B). Mean European system for cardiac operative risk evaluation I predicted risk of mortality was 36 ± 24 and 16 ± 15, respectively. The hospital mortality rate was 15.3% in group A and 7.1% in group B. Survival rate after 1, 5, and 10 years was 65.4%, 57.7%, and 50% for group A and 92.9%, 85.7%, and 78.6% for group B. Freedom from reoperation at 1, 5, and 10 years was 92.3%, 84.6%, and 76.9% for group A and 90.9%, 90.9%, and 90.9% for group B. Mean follow-up was 53 ± 8 months.

CONCLUSIONS

Although this complex operation is associated with high perioperative mortality, the long-term results are acceptable in patients where there are not suitable alternative procedures.