Restrictive filling pattern in ischemic cardiomyopathy: Insights after surgical ventricular restoration

Left ventricle diastolic vortex ring characterization in ischemic cardiomyopathy: insight into atrio-ventricular interplay

Diastolic vortex ring (VR) plays a key role in the blood-pumping function exerted by the left ventricle (LV), with altered VR structures being associated with LV dysfunction. Herein, we sought to characterize the VR diastolic alterations in ischemic cardiomyopathy (ICM) patients with systo-diastolic LV dysfunction, as compared to healthy controls, in order to provide a more comprehensive understanding of LV diastolic function. 4D Flow MRI data were acquired in ICM patients (n = 15) and healthy controls (n = 15). The λ2 method was used to extract VRs during early and late diastolic filling. Geometrical VR features, e.g., circularity index (CI), orientation (α), and inclination with respect to the LV outflow tract (ß), were extracted. Kinetic energy (KE), rate of viscous energy loss ( EL ˙ ), vorticity (W), and volume (V) were computed for each VR; the ratios with the respective quantities computed for the entire LV were derived. At peak E-wave, the VR was less circular (p = 0.032), formed a smaller α with the LV long-axis (p = 0.003) and a greater ß (p = 0.002) in ICM patients as compared to controls. At peak A-wave, CI was significantly increased (p = 0.034), while α was significantly smaller (p = 0.016) and β was significantly increased (p = 0.036) in ICM as compared to controls. At both peak E-wave and peak A-wave,EL ˙ VR / EL ˙ LV , WVR/WLV, and VVR/VLV significantly decreased in ICM patients vs. healthy controls. KEVR/VVR showed a significant decrease in ICM patients with respect to controls at peak E-wave, while VVR remained comparable between normal and pathologic conditions. In the analyzed ICM patients, the diastolic VRs showed alterations in terms of geometry and energetics. These derangements might be attributed to both structural and functional alterations affecting the infarcted wall region and the remote myocardium.

Ischemic cardiomyopathy: epidemiology, pathophysiology, outcomes, and therapeutic options

Ischemic cardiomyopathy (ICM) is the most prevalent cause of heart failure (HF) in developed countries, with significant morbidity and mortality, despite constant improvements in the management of coronary artery disease. Current literature on this topic remains fragmented. Therefore, this review aimed to summarize the most recent data on ICM, focusing on its definition, epidemiology, outcomes, and therapeutic options. The most widely accepted definition is represented by a left ventricular dysfunction in the presence of significant coronary artery disease. The prevalence of ICM is largely influenced by age and sex, with older individuals and males being more affected. Its pathophysiology is characterized by plaque buildup, thrombus formation, hypoperfusion, ischemic cell death, and left ventricular remodeling. Despite improvements in therapy, ICM still represents a public health burden, with a 1-year mortality rate of 16% and a 5-year mortality rate of approximately 40% in the USA and Europe. Therefore, optimization of cardiovascular function, prevention of progressive remodeling, reduction of HF symptoms, and improved survival are the main goals of treatment. Therapeutic options for ICM include lifestyle changes, optimal medical therapy, revascularization, device therapy, mechanical circulatory support, and cardiac transplantation. Personalized management strategies and tailored patient care are needed to improve the outcomes of patients with ICM.

AATS 2023: Left ventricular restoration with scar exclusion in the surgical treatment for ischemic heart failure

OBJECTIVE

Post-infarction myocardial scar as detected by cardiac magnetic resonance (CMR) is associated with adverse left ventricular (LV) remodeling and negatively affects the prognosis. We sought to analyze the impact of left ventricular restoration (LVR) with asynergic scar exclusion on long-term outcomes for patients with ischemic heart failure (IHF).

METHODS

From January 2005, 134 consecutive patients with IHF underwent scar-exclusive LVR. Among the 131 survivors, 108 patients had paired late gadolinium enhancement (LGE)-CMR preoperatively and one year after, and represent the study population. Patients were divided into two groups according to whether their post-LVR residual percentage of scarred LV perimeter was <35% (%Scar <35; n = 55) or more (%Scar ≥35; n = 53). We compared the two groups, by looking at LGE-CMR outcomes, and at long-term survival and cardiac event (hospitalization for cardiac causes)-free survival.

RESULTS

Postoperative LV end-systolic volume index decreased significantly and ejection fraction increased with significant increase in stroke volume index (P < 0.05 for both). LV diastolic function of the left atrial volume index was significantly improved in patients with residual %Scar <35 than in those with %Scar ≥35 (P interaction = 0.005). Median survival in patients with residual %Scar <35 and ≥ 35 were 8.3 (4.5-12.2) years and 6.8 (1.8-11.8) years respectively (P = 0.106). Median cardiac event-free survival in patients with %Scar <35 and ≥ 35 were 8.0 (3.9-12.1) years and 4.8 (0.8-8.8) years respectively (P < 0.001).

CONCLUSIONS

Scar-exclusive LVR yielded sustainable improvement in LV function and favorable long-term survival regardless of the extent of residual scar. The LVR should be performed to attain scar exclusion in the surgical treatment for IHF, which in turn might protectively affect LV diastolic function and cardiac event-free survival.

Importance of Tissue Doppler Evaluation in Dilated Cardiomyopathy: The Value of Diastolic Filling Pattern as a Prognostic Predictor

(1) Background: The presence of restrictive left ventricular diastolic filling pattern (LVDFP) is associated with an unfavorable prognosis in many cardiac diseases, but few data are available on the prognostic implications of this pattern in patients with dilated cardiomyopathy (DCM). We aimed to establish the main prognostic predictors at the 1- and 5-year follow-ups in DCM patients and the value of restrictive LVDFP in increasing morbidity and mortality. (2) Methods: A prospective study of 143 patients with DCM divided in non-restrictive LVDFP group (95 patients) and restrictive group (47 patients). The patients were evaluated at a 5-year follow-up through an in-patient visit during the pre-pandemic period and hybrid methods (face-to-face, teleconsultation and home monitoring with a telemedicine application) during the pandemic period. Statistical analysis compared the two groups in terms of NYHA class, quality of life, hospitalizations/emergency department (ED) visits due to HF exacerbation and total mortality. (3) Results: The mortality rate in the restrictive group was markedly higher than that in the non-restrictive group at 1 year (17.02% vs. 10.59%, respectively, p < 0.05) and at 5 years (68.08% vs. 50.53%, p < 0.05). In the restrictive group, hospitalizations/ED visits due to HF decompensations at 1 year were significantly higher (85.11% vs. 57.89%, p < 0.05), with hospitalizations for ventricular arrhythmia being almost three times higher (21.28% vs. 7.37%, respectively, p < 0.05). The percentage of patients with a favorable evolution (in terms of NYHA class and quality of life) at the 1- and 5-year follow-ups were higher in the non-restrictive LVDFP group. The main prognostic predictors in patients with DCM at the 1-year follow-up were: restrictive LVDFP, age > 75 years, markedly dilated LV, comorbidities (DM, COPD), 2nd-degree mitral regurgitation and severe pulmonary hypertension (p < 0.05). (4) Conclusions: At the 1- and 5-year follow-ups, the presence of the restrictive LVDFP in DCM patients was independently associated with a poor prognosis, being the best clinical predictor for unfavorable evolution, after adjustment for other well-established predictive parameters in DCM patients.

Predictive Value of Two-Dimensional Speckle-Tracking Echocardiography in Patients Undergoing Surgical Ventricular Restoration

Objectives

Parameters of left ventricular (LV) mechanics, obtained from speckle-tracking echocardiography (STE), were found to be of prognostic value in patients with heart failure and those who underwent cardiac surgery. This study aimed to assess the value of STE in patients scheduled to undergo surgical ventricular restoration (SVR).

Methods

A total of 158 consecutive patients with baseline STE who underwent SVR due to an LV anteroapical aneurysm were included in the analysis. Preoperative longitudinal STE parameters were evaluated for their association with an outcome, defined as all-cause mortality, LV assist device implantation, or heart transplantation. The echocardiographic follow-up to assess the change in the regional function of the segments remote from the aneurysm was performed in 43 patients at a median of 10 months [interquartile range (IQR): 6–12.7 months] after SVR.

Results

During a median follow-up of 5.1 years (IQR: 1.6–8.7 years), events occurred in 68 patients (48%). Less impaired mean basal end-systolic longitudinal strain (BLS) with a cutoff value ≤ −10.1 % demonstrated a strong association with event-free survival, also in patients with an LV shape corresponding to an intermediate shape between aneurysmal and globally akinetic. Initially hypo- or akinetic basal segments with preoperative end-systolic strain ≤ −7.8% showed a greater improvement in wall motion at the short-term follow up.

Conclusion

Patients with less impaired preoperative BLS exhibited a better event-free survival after SVR, also those with severe LV remodeling. The preserved preoperative segmental longitudinal strain was associated with a greater improvement in regional wall motion after SVR. BLS assessment may play a predictive role in patients with an LV anteroapical aneurysm who are scheduled to undergo SVR.

Clinical and hemodynamic outcomes of the Dor procedure in adults with ischemic cardiomyopathy

Ischemic cardiomyopathy continues to be a major contributor to congestive heart failure, which places a significant burden on our healthcare system. Improving medications and different coronary revascularization strategies are the mainstays in the management of ischemic cardiomyopathy. Although medications and mechanical circulatory support are playing an ever-increasing role, cardiac transplantation remains the gold standard for treating advanced heart failure. Given the small number of available and suitable donor hearts, transplantation is limited for the majority of patients. Surgical ventricular restoration has repeatedly been suggested as a viable alternative in managing heart failure in select patients, as it is believed that surgically returning the ventricle to its original dimensions is possible and associated with favorable outcomes. The purpose of this manuscript is to comprehensively review the current literature on various surgical strategies for ventricular restoration. We also contextualize the published data with respect to ventricular function, volume, structure, arrhythmias, mitral regurgitation, and clinical outcomes.

Left ventricular function and survival in ischemic cardiomyopathy: Implications for surgical ventricular restoration

Objectives

This pilot study evaluates the association of relative wall thickness (RWT) on survival in patients with ischemic cardiomyopathy (ICM). We hypothesized that patients with preserved RWT may be better candidates for surgical ventricular restoration than those with thinner RWT.

Methods

Echocardiography was performed in 165 consecutive patients (aged 58.2 ± 14.7 years) divided into 2 groups based on RWT values. Group 1 had patients with preserved RWT and group 2 had patients with reduced RWT.

Results

There were 120 (72.7%) patients with hypertension and 112 (67.8%) patients had diabetes mellitus. The patients with preserved RWT (group 1) had significantly more hypertension and diabetes. The patients with decreased RWT (group 2) were in a higher New York Heart Association functional class and had significantly greater incidence of anterior wall myocardial infarction. The entire cohort was followed over 24 months (group 1: n = 117 and group 2: n = 48). The overall all-cause mortality in group 1 (preserved RWT) was 7 (5.9%) and in group 2 (reduced RWT) was 35 (72.9%) (P < .0001). When readmission for congestive heart failure was analyzed, group 2 patients with lower RWT (P < .0001) had an increased rate of readmissions for heart failure.

Conclusions

In patients with ischemic cardiomyopathy, a lower RWT indicative of dilated LV remodeling was associated with increased mortality and readmission for heart failure. The RWT may be a simple benchmark of viable or contractile myocardium in ICM. It can be hypothesized that patients with preserved RWT may benefit from surgical ventricular restoration.

HDAC Inhibition Reverses Preexisting Diastolic Dysfunction and Blocks Covert Extracellular Matrix Remodeling

BACKGROUND

Diastolic dysfunction (DD) is associated with the development of heart failure and contributes to the pathogenesis of other cardiac maladies, including atrial fibrillation. Inhibition of histone deacetylases (HDACs) has been shown to prevent DD by enhancing myofibril relaxation. We addressed the therapeutic potential of HDAC inhibition in a model of established DD with preserved ejection fraction.

METHODS

Four weeks after uninephrectomy and implantation with deoxycorticosterone acetate pellets, when DD was clearly evident, 1 cohort of mice was administered the clinical-stage HDAC inhibitor ITF2357/Givinostat. Echocardiography, blood pressure measurements, and end point invasive hemodynamic analyses were performed. Myofibril mechanics and intact cardiomyocyte relaxation were assessed ex vivo. Cardiac fibrosis was evaluated by picrosirius red staining and second harmonic generation microscopy of left ventricle (LV) sections, RNA sequencing of LV mRNA, mass spectrometry-based evaluation of decellularized LV biopsies, and atomic force microscopy determination of LV stiffness. Mechanistic studies were performed with primary rat and human cardiac fibroblasts.

RESULTS

HDAC inhibition normalized DD without lowering blood pressure in this model of systemic hypertension. In contrast to previous models, myofibril relaxation was unimpaired in uninephrectomy/deoxycorticosterone acetate mice. Furthermore, cardiac fibrosis was not evident in any mouse cohort on the basis of picrosirius red staining or second harmonic generation microscopy. However, mass spectrometry revealed induction in the expression of >100 extracellular matrix proteins in LVs of uninephrectomy/deoxycorticosterone acetate mice, which correlated with profound tissue stiffening based on atomic force microscopy. ITF2357/Givinostat treatment blocked extracellular matrix expansion and LV stiffening. The HDAC inhibitor was subsequently shown to suppress cardiac fibroblast activation, at least in part, by blunting recruitment of the profibrotic chromatin reader protein BRD4 (bromodomain-containing protein 4) to key gene regulatory elements.

CONCLUSIONS

These findings demonstrate the potential of HDAC inhibition as a therapeutic intervention to reverse existing DD and establish blockade of extracellular matrix remodeling as a second mechanism by which HDAC inhibitors improve ventricular filling. Our data reveal the existence of pathophysiologically relevant covert or hidden cardiac fibrosis that is below the limit of detection of histochemical stains such as picrosirius red, highlighting the need to evaluate fibrosis of the heart using diverse methodologies.

Prognostic value of natriuretic peptides and restrictive filling pattern before surgical ventricular restoration

OBJECTIVE

Both increased natriuretic peptide levels and restrictive filling pattern (RFP) are important risk predictors in patients with heart failure. The aim of this study was to examine the role of the combined use of natriuretic peptide and RFP for the prognostic stratification of patients with ischemic cardiomyopathy undergoing surgical ventricular restoration in the Biomarker Plus study.

METHODS

A total of 186 patients (aged 64 ± 10 years) underwent echocardiographic study and N-terminal pro-B-type natriuretic peptide assay at baseline (before surgical ventricular restoration). Patients were divided into 4 groups depending on baseline diastolic filling pattern (RFP/no RFP) and N-terminal pro-B-type natriuretic peptide level (less than or greater than or equal to the upper tertile value of 2003 ŋg/L). RFP was defined as E/A ratio ≥2. All-cause death or heart failure hospitalizations within 36-month follow-up were analyzed.

RESULTS

Despite similar ejection fraction, volumes, and mass, the 4 groups presented distinct clinical and structural pattern of presurgical ventricular restoration ventricular remodeling and significantly different clinical outcome after surgical unloading. During follow-up, 67 patients died or were hospitalized for heart failure (36%). High N-terminal pro-B-type natriuretic peptide levels and RFP, considered individually, were significantly associated with outcome (P < .0001). The combination of both was associated with the highest adjusted hazard of adverse events (hazard ratio, 3.63; 95% CI, 1.73-7.6; P < .0001).

CONCLUSIONS

The simultaneous use of 2 markers, 1 biological and 1 echocardiographic, may allow better prognostic stratification and characterization of the distinct structural and clinical phenotypes in a population of patients with ischemic cardiomyopathy undergoing surgical ventricular restoration. This approach could be useful in the decision-making process to guide treatment choices in patients with ischemic cardiomyopathy.