Acute and Chronic Changes in Myocardial Work Parameters in Patients with Severe Primary Mitral Regurgitation Undergoing Transcatheter Edge-to-Edge Repair

Increased Afterload in Patients With Acute Reduction in Left Ventricular Ejection Fraction Following Mitral Valve Transcatheter Edge-to-Edge Repair

AIM

The mechanisms and clinical importance of acute reduction (ARD) in left ventricular (LV) function following transcatheter edge-to-edge repair (TEER) for mitral regurgitation (MR) remains unclear. This study aimed to non-invasively evaluate the cardio-mechanical parameters, including end-systolic elastance (Ees) and arterial elastance (Ea), to explore their association with ARD following mitral TEER.

METHODS AND RESULTS

We performed a retrospective analysis of serial transthoracic echocardiography (TTE) studies before and after mitral TEER. Cardio-mechanical parameters were evaluated non-invasively using a modified single-beat method. After the exclusion of nine patients requiring intravenous catecholamine infusion, the study cohort comprised 49 consecutive patients (25 men; mean age: 81 ± 9 years) with successful mitral TEER. ARD in LV function was defined as a decrease in LV ejection fraction (LVEF) of ≥5 points following the procedure by TTE, which was reported in 18 patients. The hospitalization period was longer in patients with ARD in LVEF than in those without ARD (5.5 days vs. 4 days, p = 0.031). Following improvement in MR, Ea increased (1.54 ± 0.49 mmHg/mL vs. 1.84 ± 0.55 mmHg/mL, p = 0.004). Linear regression analysis revealed a correlation between Δtotal stroke volume (SV) and ΔEa (r = 0.614, p < 0.0001). Notably, ΔEa was higher in patients with ARD in LVEF than in those without ARD in LVEF (0.60 ± 0.73 mmHg/mL vs. 0.14 ± 0.39 mmHg/mL, p = 0.006).

CONCLUSION

ARD in LVEF after mitral TEER was reported in a substantial proportion of patients and may have prognostic implications. Evaluating cardio-mechanical parameters may aid in understanding complex hemodynamics and guiding treatment strategies for patients with MR undergoing TEER.

Cardiac adaptations in young triathletes: a 9-month longitudinal study during the peak height velocity period

PURPOSE

The present study examined the influence of endurance training on the morphological and functional heart adaptations in young athletes throughout a longitudinal 9-month follow-up period during the adolescent peak height velocity (PHV).

METHODS

Thirty-six 13- to 15-year-old males (twenty-three triathletes and thirteen untrained peers) were evaluated before and after a 9-month period during PHV. Maximal oxygen uptake (V ˙ O 2 max ) and power atV ˙ O 2 max were assessed during incremental cycling test. Resting echocardiography was performed to evaluate left ventricular (LV) morphology with standard parameters and using an original approach to assess LV shape. In addition, LV function was evaluated with advanced echocardiography tools including LV strains and myocardial work analyses from speckle-tracking echocardiography.

RESULTS

AbsoluteV ˙ O 2 max increased similarly in both groups but power atV ˙ O 2 max only significantly increased in triathletes (from 232 ± 46 to 264 ± 46 W, p < 0.001). Maturation had a significant effect on LV morphology with an enlargement in both groups. Endurance training induced additional adaptations in young triathletes, i.e., a cardiac remodeling characterized by an increase in LV length (from 7.5 ± 0.7 to 8.2 ± 0.6 cm, p < 0.01). The stroke volume was greater in young triathletes compared to untrained peers but with a constant difference throughout the 9-month period. Finally, speckle-tracking echocardiography and myocardial work remained unchanged during the follow-up and similar between groups.

CONCLUSION

Endurance training induced morphological adaptations during the PHV period without significant adaptation in LV function as evidenced by the absence of specific changes in LV strains and myocardial work.

Mitral Transcatheter Edge-to-Edge Repair and Clinical Value of Novel Echocardiographic Biomarkers: A Hypothesis-Generating Study

BACKGROUND

Longitudinal data on reverse cardiac remodeling and outcomes after transcatheter edge-to-edge repair (TEER) are limited.

METHODS

A total of 78 patients with severe mitral regurgitation (MR) were included retrospectively. All patients had echocardiography at baseline and again six months after TEER. They were monitored for a primary composite endpoint, consisting of heart failure hospitalization and cardiovascular death, over 13 months.

RESULTS

Significant decreases in the left ventricular ejection fraction (LVEF), all myocardial work indices (except global wasted work), and the left atrial reservoir were observed after TEER. Additionally, there was a decrease in the pulmonary artery systolic pressure and an increase in the tricuspid annular plane systolic excursion/pulmonary artery systolic pressure (TAPSE/PASP) ratio. A post-TEER TAPSE/PASP ratio of <0.47 (HR: 4.76, p-value = 0.039), and a post-TEER left atrial reservoir of <9.0% (HR: 2.77, p-value = 0.047) were associated with the primary endpoint.

CONCLUSIONS

Echocardiography post-TEER reflects impairment in ventricular performance due to preload reduction and right ventricle and pulmonary artery coupling improvement. Short-term echocardiography after TEER identifies high-risk patients who could benefit from a close clinical follow-up. The prognostic significance of LA strain and the TAPSE/PASP ratio should be validated in subsequent large-scale prospective studies.

From ejection fraction, to myocardial strain, and myocardial work in echocardiography: Clinical impact and controversies

Enhancing an echocardiographic tool, aimed to detect even subtle left ventricular (LV) systolic function abnormalities, capable of obtaining both early diagnosis and risk prediction of heart disease, represents an ambitious, attractive, and arduous purpose in the modern era of cardiovascular imaging. Ideally, that tool should be simple, reliable, and reproducible, in order to be concretely applied in routine clinical practice. Importantly, that technique should be physiologically plausible and useful both at the population-level, as well as in the individual subject. For a long time, LV ejection fraction (EF) has been considered the first-line parameter for assessing LV global systolic function, strictly related to the prognosis, at least in some settings. However, LV EF limitations are well-known, even though frequently overemphasized, including its load-dependency. Therefore, myocardial strain techniques have been proposed, deemed able to disclose even subtle early LV function anomalies. Nevertheless, many disadvantages of myocardial strain have been reported as well. More recently, myocardial work (MW) analysis has been introduced as a new echocardiographic tool for the evaluation of LV global systolic function, attempting to overcome EF and strain disadvantages. However, MW has shown many limits as well. Notwithstanding, LV EF still remains a landmark functional classification marker for heart failure and cardiac oncology, allowing reliable fast reassessment of LV function changes during patient management, in order to guide treatment in individual cases as well. Notably, global longitudinal strain and MW parameters seem to show better meaningful results at the population-level, but controversial clinical impact, major limitations, wide cut-offs spread and overlap, when the single value needs to be applied to the single case. Taking into account the recent literature-based evidence, the scope of the present narrative critical review is trying to delineate the different types of information given by the described LV global systolic function parameters, both at the population-level and in the individual case, in order to trace a comparative analysis of advantages and limitations in clinical practice.

Impact of Percutaneous Mitral Valve Repair on Left Atrial Strain and Atrial Fibrillation Progression

Transcatheter edge-to-edge repair (TEER) currently represents a valuable therapeutic option for patients with severe mitral regurgitation (MR) considered at high surgical risk. Besides symptoms and left ventricular (LV) echocardiographic improvements upon TEER, it has been postulated that left atrial (LA) function plays a prognostic role. The aims of our study were to evaluate LA changes after TEER, measured by two-dimensional speckle-tracking echocardiography analysis (2D-STE), their association with atrial fibrillation (AF) occurrence, and relative arrhythmic burden. We considered in a single-center study 109 patients affected by symptomatic severe MR undergoing TEER from February 2015 to April 2022. By 2D-STE, LA reservoir (R_s), conduct (D_s), and contractile (C_s) strains were assessed along with four-chamber emptying fraction (LAEF-4CH) before, 1, 6, and 12 months following TEER. Statistical analysis for comparison among baseline, and follow-ups after TEER was carried out by ANOVA, MANOVA, and linear regression. Successful TEER significantly improved LV dimensions and LA performances, as indicated by all strain components, and LAEF-4CH after 1 year. Strikingly, a significant reduction in arrhythmic burden was observed, since only one case of subclinical AF detected by a previously implanted cardiac electronic device was found in the cohort of sinus rhythm patients (n = 48) undergone TEER; in addition, ventricular rate was reduced in the AF cohort (n = 61) compared to baseline, together with few episodes of nonsustained ventricular tachycardias (5/61, 8.2%) after MR improvement. Overall, TEER was associated with improved cardiac performance, LA function amelioration, and reduced arrhythmic burden.