Placental senescence pathophysiology is shared between peripartum cardiomyopathy and preeclampsia in mouse and human

Peripartum cardiomyopathy (PPCM) is an idiopathic form of pregnancy-induced heart failure associated with preeclampsia. Circulating factors in late pregnancy are thought to contribute to both diseases, suggesting a common underlying pathophysiological process. However, what drives this process remains unclear. Using serum proteomics, we identified the senescence-associated secretory phenotype (SASP), a marker of cellular senescence associated with biological aging, as the most highly up-regulated pathway in young women with PPCM or preeclampsia. Placentas from women with preeclampsia displayed multiple markers of amplified senescence and tissue aging, as well as overall increased gene expression of 28 circulating proteins that contributed to SASP pathway enrichment in serum samples from patients with preeclampsia or PPCM. The most highly expressed placental SASP factor, activin A, was associated with cardiac dysfunction or heart failure severity in women with preeclampsia or PPCM. In a murine model of PPCM induced by cardiomyocyte-specific deletion of the gene encoding peroxisome proliferator-activated receptor γ coactivator-1α, inhibiting activin A signaling in the early postpartum period with a monoclonal antibody to the activin type II receptor improved heart function. In addition, attenuating placental senescence with the senolytic compound fisetin in late pregnancy improved cardiac function in these animals. These findings link senescence biology to cardiac dysfunction in pregnancy and help to elucidate the pathogenesis underlying cardiovascular diseases of pregnancy.

Association between right ventricular global longitudinal strain and mortality in intermediate-risk pulmonary embolism

BACKGROUND

Right ventricular (RV) systolic dysfunction has been identified as a prognostic marker for adverse clinical events in patients presenting with acute pulmonary embolism (PE). However, challenges exist in identifying RV dysfunction using conventional echocardiography techniques. Strain echocardiography is an evolving imaging modality which measures myocardial deformation and can be used as an objective index of RV systolic function. This study evaluated RV Global Longitudinal Strain (RVGLS) in patients with intermediate risk PE as a parameter of RV dysfunction, and compared to traditional echocardiographic and CT parameters evaluating short-term mortality.

METHODS

Retrospective single center cohort study of 251 patients with intermediate-risk PE between 2010 and 2018. The primary outcome was all-cause mortality at 30 days. Statistical analysis evaluated each parameter comparing survivors versus non-survivors at 30 days. Receiver operating characteristic (ROC) curves and Kaplan-Meier curves were used for comparison of the two cohorts.

RESULTS

Altogether 251 patients were evaluated. Overall mortality rate was 12.4%. Utilizing an ROC curve, an absolute cutoff value of 17.7 for RVGLS demonstrated a sensitivity of 93% and specificity of 70% for observed 30-day mortality. Individuals with an RVGLS ≤17.7 had a 25 times higher mortality rate than those with RVGLS above 17.7 (HR 25.24, 95% CI = 6.0-106.4, p < .001). Area under the curve was (.855), RVGLS outperformed traditional echocardiographic parameters, CT findings, and cardiac biomarkers on univariable and multivariable analysis.

CONCLUSIONS

Reduced RVGLS values on initial echocardiographic assessment of patients with intermediate-risk PE identified patients at higher risk for mortality at 30 days.

Interatrial shunt therapy in advanced heart failure: Outcomes from the open-label cohort of the RELIEVE-HF trial

AIMS

Heart failure (HF) outcomes remain poor despite optimal guideline-directed medical therapy (GDMT). We assessed safety, effectiveness, and transthoracic echocardiographic (TTE) outcomes during the 12 months after Ventura shunt implantation in the RELIEVE-HF open-label roll-in cohort.

METHODS AND RESULTS

Eligibility required symptomatic HF despite optimal GDMT with ≥1 HF hospitalization in the prior year or elevated natriuretic peptides. The safety endpoint was device-related major adverse cardiovascular or neurological events at 30 days, compared to a prespecified performance goal. Effectiveness evaluations included the Kansas City Cardiomyopathy Questionnaire (KCCQ) at baseline, 1, 3, 6, and 12 months and TTE at baseline and 12 months. Overall, 97 patients were enrolled and implanted at 64 sites. Average age was 70 ± 11 years, 97% were in New York Heart Association class III, and half had left ventricular ejection fraction (LVEF) ≤40%. The safety endpoint was achieved (event rate 0%, p < 0.001). KCCQ overall summary score was improved by 12-16 points at all follow-up timepoints (all p < 0.004), with similar outcomes in patients with reduced and preserved LVEF. At 12 months, left ventricular end-systolic and end-diastolic volumes were reduced (p = 0.020 and p = 0.038, respectively), LVEF improved (p = 0.009), right ventricular end-systolic and end-diastolic areas were reduced (p = 0.001 and p = 0.030, respectively), and right ventricular fractional area change (p < 0.001) and tricuspid annular plane systolic excursion (p < 0.001) improved.

CONCLUSION

Interatrial shunting with the Ventura device was safe and resulted in favourable clinical effects in patients with HF, regardless of LVEF. Improvements of left and right ventricular structure and function were consistent with reverse myocardial remodelling. These results would support the potential of this shunt device as a treatment for HF.

Junctional AV ablation in patients with atrial fibrillation undergoing cardiac resynchronization therapy (JAVA-CRT): results of a multicenter randomized clinical trial pilot program

Introduction

Cardiac resynchronization therapy (CRT) improves outcomes in sinus rhythm, but the data in atrial fibrillation (AF) is limited. Atrio-ventricular junctional ablation (AVJA) has been proposed as a remedy. The objective was to test if AVJA results in LV end-systolic volume (ESV) reduction ≥ 15% from baseline to 6 months.

Methods

The trial was a prospective multicenter randomized trial in 26 patients with permanent AF who were randomized 1:1 to CRT-D with or without AVJA.

Results

LVESV improved similarly by at least 15% in 5/10 (50%) in the CRT-D-only arm and in 6/12 (50%) in the AVJA + CRT-D arm (OR = 1.00 [0.14, 7.21], p = 1.00). In the CRT-D-only arm, the median 6-month improvement in LVEF was 9.2%, not different from the AVJA + CRT-D arm, 8.2%. When both groups were combined, a significant increase in LVEF was observed (25.4% at baseline vs 36.2% at 6 months, p = 0.002). NYHA class from baseline to 6 months for all patients combined improved 1 class in 15 of 24 (62.5%), whereas 9 remained in the same class and 0 degraded to a worse class.

Conclusion

In patients with permanent AF, reduced LVEF, and broad QRS who were eligible for CRT, there was insufficient evidence that AVJA improved echocardiographic or clinical outcomes; the results should be interpreted in light of a smaller than planned sample size. CRT, however, seemed to be effective in the combined study cohort overall, suggesting that CRT can be reasonably deployed in patients with AF.

Trial registration

ClinicalTrials.gov Identifier: NCT02946853.

Echocardiographic and clinical predictors of cardiac amyloidosis: limitations of apical sparing

Aims

The accuracy of an apical‐sparing strain pattern on transthoracic echocardiography (TTE) for predicting cardiac amyloidosis (CA) has varied in prior studies depending on the underlying cohort. We sought to evaluate the performance of apical sparing and other TTE strain findings to screen for CA in an unselected population and determine the frequency that patients with echocardiographic concern for CA undergo evaluation for amyloidosis in clinical practice.

Methods and results

As strain is routinely performed at our institution on all clinical TTEs, we identified all TTEs performed from 2016 through 2019 with reported concern for CA or apical sparing. We determined the performance characteristics for echocardiographic strain findings in discriminating CA including apical sparing, the ejection fraction to global longitudinal strain ratio (EF/GLS), and the septal apical–septal basal ratio (SA/SB); other clinical predictors of confirmed CA; and predictors of patients who underwent complete evaluation for CA. CA was confirmed by endomyocardial biopsy or diagnostic cardiac imaging. A total of 547 TTEs, representing 451 patients, reported concern for CA and had adequate strain for analysis. A total of 111 patients underwent complete evaluation for amyloidosis with 100 patients undergoing complete cardiac evaluation for CA. In those 100 patients, multivariable predictors of confirmed CA were age [odds ratio (OR) 3.37 per 5 years], a visual apical‐sparing pattern (OR 10.85), and left ventricular ejection fraction (LVEF)/GLS > 4.1 (OR 35.37). CA was less likely in those with coronary artery disease (OR 0.04), hypertension (OR 0.18), and increased systolic blood pressure (OR 0.60 per 5 mm Hg increase). SA/SB [area under the curve (AUC) 0.72, 95% confidence interval (CI) 0.60–0.84] and LVEF/GLS (AUC 0.72, 95% CI 0.60–0.84) both had improved discrimination for CA compared with the apical‐sparing ratio (AUC 0.66, 95% CI 0.54–0.79). Many patients with suggestive TTE findings did not receive an evaluation for amyloidosis. Complete evaluation was more likely with Caucasian race (OR 2.1), increased septal thickness (OR 1.4), increased body mass index (OR 1.2), and if the report specifically stated ‘amyloid’ (OR 1.9). Evaluations were less likely in patients with comorbidities. While hypertension reduced the likelihood of evaluating for CA, 34% of patients with CA had hypertension (>130/80 mm Hg) at time of diagnosis.

Conclusions

In a broad population of patients undergoing TTE, apical sparing on strain imaging increased the likelihood of CA diagnosis but with modest sensitivity and specificity. GLS/EF ratio may be a more reliable tool to screen for CA. The low rate of complete evaluation in patients with concerning TTE findings indicates a strong need for practice improvement and enhanced disease awareness.

Prognostic significance of longitudinal strain in dilated cardiomyopathy with recovered ejection fraction

OBJECTIVE

Patients with non-ischaemic dilated cardiomyopathy (NICM) may experience a normalisation in left ventricular ejection fraction (LVEF). Although this correlates with improved prognosis, it does not correspond to a normalisation in the risk of death during follow-up. Currently, there are no tools to risk stratify this population. We tested the hypothesis that absolute global longitudinal strain (aGLS) is associated with mortality in patients with NICM and recovered ejection fraction (LVEF).

METHODS

We designed a retrospective, international, longitudinal cohort study enrolling patients with NICM with LVEF <40% improved to the normal range (>50%). We studied the relationship between aGLS measured at the time of the first recording of a normalised LVEF and all-cause mortality during follow-up. We considered aGLS >18% as normal and aGLS ≥16% as of potential prognostic value.

RESULTS

206 patients met inclusion criteria. Median age was 53.5 years (IQR 44.3-62.8) and 56.6% were males. LVEF at diagnosis was 32.0% (IQR 24.0-38.8). LVEF at the time of recovery was 55.0% (IQR 51.7-60.0). aGLS at the time of LVEF recovery was 13.6%±3.9%. 166 (80%) and 141 (68%) patients had aGLS ≤18% and <16%, respectively. During a follow-up of 5.5±2.8 years, 35 patients (17%) died. aGLS at the time of first recording of a recovered LVEF correlated with mortality during follow-up (HR 0.90, 95% CI 0.91 to 0.99, p=0.048 in adjusted Cox model). No deaths were observed in patients with normal aGLS (>18%). In unadjusted Kaplan-Meier survival analysis, aGLS <16% was associated with higher mortality during follow-up (31 deaths (22%) in patients with GLS <16% vs 4 deaths (6.2%) in patients with GLS ≥16%, HR 3.2, 95% CI 1.1 to 9, p=0.03).

CONCLUSIONS

In patients with NICM and normalised LVEF, an impaired aGLS at the time of LVEF recovery is frequent and associated with worse outcomes.

Interim Analysis of the Phase II Study: Noninferiority Study of Doxorubicin with Upfront Dexrazoxane plus Olaratumab for Advanced or Metastatic Soft-Tissue Sarcoma

PURPOSE

To report the interim analysis of the phase II single-arm noninferiority trial, testing the upfront use of dexrazoxane with doxorubicin on progression-free survival (PFS) and cardiac function in soft-tissue sarcoma (STS).

PATIENTS AND METHODS

Patients with metastatic or unresectable STS who were candidates for first-line treatment with doxorubicin were deemed eligible. An interim analysis was initiated after 33 of 65 patients were enrolled. Using the historical control of 4.6 months PFS for doxorubicin in the front-line setting, we tested whether the addition of dexrazoxane affected the efficacy of doxorubicin in STS. The study was powered so that a decrease of PFS to 3.7 months would be considered noninferior. Secondary aims included cardiac-related mortality, incidence of heart failure/cardiomyopathy, and expansion of cardiac monitoring parameters including three-dimensional echocardiography. Patients were allowed to continue on doxorubicin beyond 600 mg/m2 if they were deriving benefit and were not demonstrating evidence of symptomatic cardiac dysfunction.

RESULTS

At interim analysis, upfront use of dexrazoxane with doxorubicin demonstrated a PFS of 8.4 months (95% confidence interval: 5.1-11.2 months). Only 3 patients were removed from study for cardiotoxicity, all on > 600 mg/m2 doxorubicin. No patients required cardiac hospitalization or had new, persistent cardiac dysfunction with left ventricular ejection fraction remaining below 50%. The median administered doxorubicin dose was 450 mg/m2 (interquartile range, 300-750 mg/m2).

CONCLUSIONS

At interim analysis, dexrazoxane did not reduce PFS in patients with STS treated with doxorubicin. Involvement of cardio-oncologists is beneficial for the monitoring and safe use of high-dose anthracyclines in STS.See related commentary by Benjamin and Minotti, p. 3809.

Prognostic Utility of Echocardiographic Atrial and Ventricular Strain Imaging in Patients With Cardiac Amyloidosis

OBJECTIVES

The prognostic value of echocardiographic atrial and ventricular strain imaging in patients with biopsy-proven cardiac amyloidosis was assessed.

BACKGROUND

Although left ventricular global longitudinal strain (GLS) is known to be predictive of outcome, the additive prognostic value of left (LA), right atrial (RA), and right ventricular (RV) strain is unclear.

METHODS

One hundred thirty-six patients with cardiac amyloidosis and available follow-up data were studied by endomyocardial biopsy, noncardiac biopsy with supportive cardiac imaging, or autopsy confirmation. One hundred nine patients (80%) had light-chain, 23 (17%) had transthyretin, and 4 (3%) had amyloid A type cardiac amyloidosis. GLS, RV free wall strain, peak longitudinal LA strain, and peak longitudinal RA strain were measured from apical views. Clinical and routine echocardiographic data were compared. All-cause mortality was followed (median 5 years).

RESULTS

Strain data were feasible for GLS in 127 (93%), LA strain in 119 (88%), RA strain in 117 (86%), and RV strain in 102 (75%). Strain values from all 4 chambers were significantly associated with survival. Hazard ratio (HR) and 95% confidence interval (CI) for low median strain values were as follows: GLS, HR: 2.3; 95% CI: 1.3 to 3.8 (p < 0.01); LA strain, HR: 7.5; 95% CI: 3.8 to 14.7 (p < 0.001); RA strain, HR: 3.5; 95% CI: 2.0 to 6.2 (p < 0.001); and RV free wall strain, HR: 2.8; 95% CI: 1.5 to 5.1 (p < 0.001). Peak longitudinal LA strain and RV strain remained independently associated with survival in multivariable analysis. Peak LA strain had the strongest association with survival (p < 0.001), and LA strain combined with GLS and RV free wall strain had the highest prognostic value (p < 0.001).

CONCLUSIONS

Strain data from all 4 chambers had important prognostic associations with survival in patients with biopsy-confirmed cardiac amyloidosis. Peak longitudinal LA strain was particularly associated with prognosis. Atrial and ventricular strain have promise for clinical utility.

A multi-modal diagnostic model improves detection of cardiac amyloidosis among patients with diagnostic confirmation by cardiac biopsy

BACKGROUND

Timely recognition of cardiac amyloidosis is clinically important, but the diagnosis is frequently delayed.

OBJECTIVES

We sought to identify a multi-modality approach with the highest diagnostic accuracy in patients evaluated by cardiac biopsy, the diagnostic gold standard.

METHODS

Consecutive patients (N = 242) who underwent cardiac biopsy for suspected amyloidosis within an 18-year period were retrospectively identified. Cardiac biomarker, ECG, and echocardiography results were examined for correlation with biopsy-proven disease. A prediction model for cardiac amyloidosis was derived using multivariable logistic regression.

RESULTS

The overall cohort was characterized by elevated BNP (median 727 ng/mL), increased left ventricular wall thickness (IWT; median 1.7 cm), and reduced voltage-to-mass ratio (median 0.06 mm/[g/m²]). One hundred and thirteen patients (46%) had either light chain (n = 53) or transthyretin (n = 60) amyloidosis by cardiac biopsy. A prediction model including age, relative wall thickness, left atrial pressure by E/e', and low limb lead voltage (<0.5 mV) showed good discrimination for cardiac amyloidosis with an optimism-corrected c-index of 0.87 (95% CI 0.83-0.92). The diagnostic accuracy of this model (79% sensitivity, 84% specificity) surpassed that of traditional screening parameters, such as IWT in the absence of left ventricular hypertrophy on ECG (98% sensitivity, 20% specificity) and IWT with low limb lead voltage (49% sensitivity, 91% specificity).

CONCLUSION

Among patients with an advanced infiltrative cardiomyopathy phenotype, traditional biomarker, ECG, and echocardiography-based screening tests have limited individual diagnostic utility for cardiac amyloidosis. A prediction algorithm including age, relative wall thickness, E/e', and low limb lead voltage improves the detection of cardiac biopsy-proven disease.

Effect of infarct stiffness on non-infarcted left and right ventricular tissue remodeling: a computational study based on myocardial mechano-transduction

Background/Introduction

The mechanical properties of infarcted myocardium are important determinants of cardiac pump function and risk of developing heart failure following myocardial infarction (MI).

Purpose

To better understand the effects of infarct stiffness on compensatory hypertrophy and dilation of non-infarcted tissue in the left (LV) and right ventricle (RV), by using a computational model.

Methods

The CircAdapt computational model of the human heart and circulation was applied to simulate an acute MI involving 20% of LV wall mass. The simulation was validated using previously published experimental data. Subsequently, two degrees of increased infarct stiffness were simulated. In all three simulations, a model of structural myocardial adaptation of the non-infarcted tissue was applied, based on sensing of mechanical loading of myocytes and extracellular matrix (ECM).

Results

Mild and severe stiffening of the infarct reduced the increase of LV end-diastolic volume (EDV) from +23 mL to +17 mL and +16 mL, respectively, and the increase of LV non-infarcted tissue mass from +31% to +21% and +18%. RV EDV decreased after adaptation, and mild and severe infarct stiffening reduced the decrease of RV EDV from −21 mL to −12 mL and −10 mL, respectively. Increase of RV tissue mass was reduced from +13% to +8% and +7% with mild and severe infarct stiffening. In the LV, reduced dilation and hypertrophy were driven mainly by a reduction of maximum stress in the ECM and a higher stress between the myocytes and ECM following infarct stiffening. The decreased RV hypertrophy, but not EDV reduction, was caused by a reduction of maximum RV ECM stress and maximum RV active myofiber stress.

Conclusions

Model simulations predicted that a stiffened LV infarct reduces both LV and RV non-infarcted tissue hypertrophy as well as LV dilation. In LV remodeling, maximum ECM stress and stress between myocyte and ECM played a more prominent role than in RV remodeling, while maximum active stress was more important in the RV.

Overview of all model simulations

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): This work was funded by the Netherlands Organisation for Scientific Research and the Dutch Heart Foundation.

Baseline left atrial strain is associated with clinical outcomes following cardiac resynchronization therapy in patients with intermediate electrocardiographic criteria

Background

Guidelines favor patient selection by left bundle branch block (LBBB) with QRS width ≥150 ms for cardiac resynchronization therapy (CRT). However, predicting response to CRT patients with QRS width 120 to 149 ms or non-LBBB remains difficult. Speckle tracking left atrial (LA) strain is a novel means to assess cardiac function, however its applications to CRT patients remains unclear.

Purpose

To test the hypothesis that baseline LA strain has prognostic value in CRT patients with intermediate ECG criteria.

Methods

We studied 195 patients with heart failure (HF) who underwent CRT based on routine indications: ejection fraction ≤35% and QRS width ≥120 ms. GLS was assessed using the 3 standard apical views. LA longitudinal strain was based on 12 segments from the 2 and 4-chamber apical view. Peak LA strain, a measure associated with the reservoir function of the LA, was defined as the average of peak longitudinal strain from all segments. The predefined combined clinical endpoint was death, heart transplant or left ventricular assist device (LVAD) over 4 years after CRT.

Results

LA strain was feasible in 162 (83%) of the candidates for CRT: age 64±11 years, 72% male, QRS duration 156±26 ms, 39.5% had LBBB with QRS ≥150ms, 60.5% had intermediate ECG criteria. Median LA strain was 11.0% [1.3% - 36.8%]. High LA peak strain was associated with more favorable event-free survival and Low LA Peak strain was associated with worse clinical outcome following CRT (FIGURE, p&lt;0.001). Patients with intermediate ECG criteria for CRT (non-LBBB or QRS width 120 to 149 ms) and high peak LA strain had similar outcome to those with Class I indications for CRT (LBBB and QRS≥150 ms). Multivariable analysis revealed that LA strain had independent prognostic value (hazard ratio 0.98 per LA strain %, p&lt;0.01) even after adjusted for other clinical, electrophysiological and echocardiographic covariates including QRS morphology and duration, ischemic cardiomyopathy, LVEF and global longitudinal strain.

Conclusions

Baseline peak LA strain had important prognostic value in HF patients who are candidates for CRT. Prognostic value of LA strain was most significant in CRT patients with intermediate ECG criteria (QRS 120 to 149ms or non-LBBB) and has promise for clinical applications.

LA strain and clinical outcome after CRT

Funding Acknowledgement

Type of funding source: None

Clinical and Echocardiographic Features Associated With Improved Survival in Patients With Severe Aortic Stenosis Undergoing Balloon Aortic Valvuloplasty (BAV)

BACKGROUND

Balloon aortic valvuloplasty (BAV) is used in high-risk patients with severe aortic stenosis (AS) when the benefit of transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR) is unclear. Our objective was to identify clinical or echocardiographic features that identify patients likely to benefit from BAV.

METHODS

We studied 141 consecutive patients who underwent BAV from July, 2011 to October, 2017. Clinical characteristics, routine echocardiographic parameters, and speckle tracking imaging of global longitudinal strain (GLS) were assessed before and after BAV. The primary outcome was all-cause mortality as ascertained by the National Death Index.

RESULTS

There were 141 patients, median age, 80 years (interquartile range [IQR], 74-87 years) with severe AS (median aortic valve area, 0.66 cm²; IQR, 0.53-0.79 cm²) and median mean gradient of 36 mm Hg (IQR, 27-48 mm Hg) who underwent BAV. The 1-year mortality rate was 52%. Characteristics associated with survival were New York Heart Association class I symptoms, lower brain natriuretic peptide level, higher left ventricular ejection fraction (LVEF) >53%, and higher GLS (>13.2%; absolute values were used for GLS). Landmark analysis at 60 days showed the 47 patients who underwent TAVR/SAVR after BAV had significantly better 1-year survival than those who did not (P<.001).

CONCLUSION

A high 1-year mortality rate was observed in severe AS patients selected for BAV. LVEF and left ventricular (LV)-GLS offer similar prognostic value for 1-year mortality; however, LV-GLS may have potentially increased clinical utility, as it provides a clear threshold for predicting poor outcomes compared with LVEF. As patients who undergo TAVR/SAVR have markedly improved mortality, careful consideration should be given to advance definitive valve therapy in carefully selected BAV patients.

BOLA (BolA Family Member 3) Deficiency Controls Endothelial Metabolism and Glycine Homeostasis in Pulmonary Hypertension

BACKGROUND

Deficiencies of iron-sulfur (Fe-S) clusters, metal complexes that control redox state and mitochondrial metabolism, have been linked to pulmonary hypertension (PH), a deadly vascular disease with poorly defined molecular origins. BOLA3 (BolA Family Member 3) regulates Fe-S biogenesis, and mutations in BOLA3 result in multiple mitochondrial dysfunction syndrome, a fatal disorder associated with PH. The mechanistic role of BOLA3 in PH remains undefined.

METHODS

In vitro assessment of BOLA3 regulation and gain- and loss-of-function assays were performed in human pulmonary artery endothelial cells using siRNA and lentiviral vectors expressing the mitochondrial isoform of BOLA3. Polymeric nanoparticle 7C1 was used for lung endothelium-specific delivery of BOLA3 siRNA oligonucleotides in mice. Overexpression of pulmonary vascular BOLA3 was performed by orotracheal transgene delivery of adeno-associated virus in mouse models of PH.

RESULTS

In cultured hypoxic pulmonary artery endothelial cells, lung from human patients with Group 1 and 3 PH, and multiple rodent models of PH, endothelial BOLA3 expression was downregulated, which involved hypoxia inducible factor-2α-dependent transcriptional repression via histone deacetylase 1-mediated histone deacetylation. In vitro gain- and loss-of-function studies demonstrated that BOLA3 regulated Fe-S integrity, thus modulating lipoate-containing 2-oxoacid dehydrogenases with consequent control over glycolysis and mitochondrial respiration. In contexts of siRNA knockdown and naturally occurring human genetic mutation, cellular BOLA3 deficiency downregulated the glycine cleavage system protein H, thus bolstering intracellular glycine content. In the setting of these alterations of oxidative metabolism and glycine levels, BOLA3 deficiency increased endothelial proliferation, survival, and vasoconstriction while decreasing angiogenic potential. In vivo, pharmacological knockdown of endothelial BOLA3 and targeted overexpression of BOLA3 in mice demonstrated that BOLA3 deficiency promotes histological and hemodynamic manifestations of PH. Notably, the therapeutic effects of BOLA3 expression were reversed by exogenous glycine supplementation.

CONCLUSIONS

BOLA3 acts as a crucial lynchpin connecting Fe-S-dependent oxidative respiration and glycine homeostasis with endothelial metabolic reprogramming critical to PH pathogenesis. These results provide a molecular explanation for the clinical associations linking PH with hyperglycinemic syndromes and mitochondrial disorders. These findings also identify novel metabolic targets, including those involved in epigenetics, Fe-S biogenesis, and glycine biology, for diagnostic and therapeutic development.

P2724Diagnosis of transthyretin versus light chain cardiac amyloidosis by apical sparing strain ratio in patients with clinically suspected disease

Background

Apical sparing by longitudinal strain imaging has reported utility for the diagnosis of cardiac amyloidosis. However, potential differences in the apical sparing pattern in light chain (AL) versus transthyretin (ATTR) amyloidosis in patients with high clinical suspicion for cardiac amyloidosis is not clear.

Purpose

Our objective was to test the hypothesis that echocardiographic strain imaging could determine differences in patients with clinically suspected AL and ATTR cardiac amyloidosis.

Methods

We studied 206 patients, aged 64±11, with clinically suspected cardiac amyloidosis. Routine longitudinal strain imaging analyses was performed (EchoPAC, GE Healthcare) with bulls-eye plots. After 27 exclusions (8 arrhythmia/frame rate, 19 missing/poor images), there were 179 patients. Included were 129 patients with cardiac amyloid: 42 by endomyocardial biopsy, 4 by technetium pyrophosphate scan, 65 by non-cardiac biopsy with suggestive cardiac imaging (interventricular septal thickness ≥1.2cm by echocardiography or characteristic cardiac MRI findings), 15 with multiple myeloma and suggestive cardiac imaging, and 3 by autopsy; 50 patients had a negative endomyocardial biopsy or autopsy for cardiac amyloid. The apical sparing ratio by strain imaging was calculated as the (average of apical segments) / (average of mid segments + average of basal segments).

Results

Cardiac amyloidosis patients were 79% with AL and 21% with ATTR. Applying the previously published apical sparing ratio cut-off of 1.0 for longitudinal strain imaging, sensitivity and specificity were 29% and 78%, respectively, for diagnosis of cardiac amyloidosis. Applying a ratio cut-off of 0.81 improved sensitivity to 72% with specificity of 64% and area under the curve (AUC) of 0.66. Positive and negative predictive values were 85% and 46%, respectively, at this ratio cut-off. The apical sparing ratio was significantly higher in AL and ATTR as compared to the biopsy negative group (p<0.001). Furthermore, the apical sparing ratio was significantly higher in ATTR as compared to AL (p<0.05).

Apical sparing pattern and ratio

Conclusions

Among patients with high clinical suspicion for cardiac amyloidosis, the apical sparing ratio by echocardiographic strain imaging can demonstrate differences for AL and ATTR cardiac amyloidosis and has potential for clinical utility.

Global Left Ventricular Strain at Presentation Is Associated with Subsequent Recovery in Patients with Peripartum Cardiomyopathy

BACKGROUND

Peripartum cardiomyopathy (PPCM) is a serious complication of pregnancy associated with variable degrees of left ventricular (LV) recovery. The aim of this study was to test the hypothesis that global LV strain at presentation has prognostic value in patients with PPCM.

METHODS

One hundred patients with PPCM aged 30 ± 6 years were enrolled in the multicenter Investigation in Pregnancy Associated Cardiomyopathy study along with 21 normal female control subjects. Speckle-tracking global longitudinal strain (GLS) and global circumferential strain (GCS) analysis was performed. The predefined primary combined outcome variable was death, transplantation, LV assist device implantation, or evidence of persistent LV dysfunction (LV ejection fraction [LVEF] < 50%) at 1 year.

RESULTS

GLS measurement was feasible in 110 subjects: 89 of 90 patients with PPCM (99%) with echocardiographic data and all 21 control subjects. Of 84 patients (94%) with 1-year follow-up, 21 (25%) had unfavorable primary outcomes: four LV assist device placements, two deaths, and 15 patients with persistent LV dysfunction. GLS at presentation with a cutoff of 10.6% (absolute value) was specifically associated with the subsequent primary outcome with 75% sensitivity and 95% specificity. GCS at presentation with a cutoff of 10.1% was associated with the primary outcome with 78% sensitivity and 84% specificity. GLS and GCS remained significantly associated with outcomes after adjusting for LVEF (GLS odds ratio, 2.07; P < .001; GCS odds ratio, 1.37; P = .005). GLS was significantly additive to LVEF (C statistic = 0.76-0.91, net reclassification improvement = 1.32, P < .001).

CONCLUSIONS

GLS and GCS in patients with PPCM at presentation were associated with subsequent clinical outcomes, including death, LV assist device implantation, and evidence of persistent LV dysfunction. Strain measures may add prognostic information over LVEF for risk stratification.

Registry Evaluation of Vital Information for VADs in Ambulatory Life (REVIVAL): Rationale, design, baseline characteristics, and inclusion criteria performance

INTRODUCTION

Improved understanding of the clinical course of ambulatory advanced chronic systolic heart failure may improve the provision of appropriate care and is central to the design of clinical trials in this population.

METHODS

Twenty-one implanting ventricular assist device (VAD) centers enrolled 400 subjects in the Registry Evaluation of Vital Information for VADs in Ambulatory Life (REVIVAL), a prospective, observational study in ambulatory, chronic, advanced systolic heart failure, designed to identify a cohort with an approximately 25% 1-year risk of the primary composite outcome of death, urgent transplant, or durable mechanical circulatory support. Inclusion criteria utilized only information collected during routine clinical care. Exclusion criteria identified patients with contraindications to VAD. Study inclusion required at least 1 of 10 high-risk criteria derived from established hospitalization and non-hospitalization markers of increased mortality risk. We evaluated the test performance characteristics of the high-risk criteria.

RESULTS

Data on 373 subjects evaluable for the primary composite outcome at the 1-year visit are presented. Baseline data were consistent with a less advanced cohort than Medical Arm for Mechanically Assisted Circulatory Support or Risk Assessment (MedaMACS) and Comparative Effectiveness of Left Ventricular Assist Device and Medical Management in Ambulatory Heart Failure Patients (ROADMAP). Freedom from the primary composite outcome was 75.9%. Non-hospitalization inclusion criteria identified 89% of patients with events.

CONCLUSIONS

Using routinely obtained clinical information for enrollment, REVIVAL successfully recruited an ambulatory chronic systolic heart failure cohort with an approximately 25% annual risk of the primary composite outcome. Information from this registry will be relevant to the planning of future trials of earlier VAD use and of other interventions in this population.

Systolic Stretch Characterizes the Electromechanical Substrate Responsive to Cardiac Resynchronization Therapy

OBJECTIVES

In this study, the authors tested the hypotheses that the systolic stretch index (SSI) developed by computer modeling and applied using echocardiographic strain imaging may characterize the electromechanical substrate predictive of outcome following cardiac resynchronization therapy (CRT). They included patients with QRS width 120 to 149 ms or non-left bundle branch block (LBBB), where clinical uncertainty for CRT exists. They further tested the hypothesis that global longitudinal strain (GLS) has additional prognostic value.

BACKGROUND

Response to CRT is variable. Guidelines favor patient selection by electrocardiographic LBBB with QRS width ≥150 ms.

METHODS

The authors studied 442 patients enrolled in the Adaptive CRT 94-site randomized trial with New York Heart Association functional class III-IV heart failure, ejection fraction ≤35%, and QRS ≥120 ms. A novel computer program semiautomatically calculated the SSI from strain curves as the sum of posterolateral prestretch percent before aortic valve opening and the septal rebound stretch percent during ejection. The primary endpoint was hospitalization for heart failure (HF) or death, and the secondary endpoint was death over 2 years after CRT.

RESULTS

In all patients, high longitudinal SSI (≥ group median of 3.1%) was significantly associated with freedom from the primary endpoint of HF hospitalization or death (hazard ratio [HR] for low SSI: 2.17; 95% confidence interval [CI]: 1.45 to 3.24, p < 0.001) and secondary endpoint of death (HR for low SSI: 4.06; 95% CI: 1.95 to 8.45, p < 0.001). Among the 203 patients with QRS 120 to 149 ms or non-LBBB, those with high longitudinal SSI (≥ group median of 2.6%) had significantly fewer HF hospitalizations or deaths (HR for low SSI: 2.08; 95% CI: 1.27 to 3.41, p = 0.004) and longer survival (HR for low SSI: 5.08; 95% CI: 1.94 to 13.31, p < 0.001), similar to patients with LBBB ≥150 ms. SSI by circumferential strain had similar associations with clinical outcomes, and GLS was additive to SSI in predicting clinical events (p = 0.001).

CONCLUSIONS

Systolic stretch by strain imaging characterized the myocardial substrate associated with favorable CRT response, including in the important patient subgroup with QRS width 120 to 149 ms or non-LBBB. GLS had additive prognostic value.

Structural and Functional Phenotyping of the Failing Heart: Is the Left Ventricular Ejection Fraction Obsolete?

Diagnosis, prognosis, treatment, and development of new therapies for diseases or syndromes depend on a reliable means of identifying phenotypes associated with distinct predictive probabilities for these various objectives. Left ventricular ejection fraction (LVEF) provides the current basis for combined functional and structural phenotyping in heart failure by classifying patients as those with heart failure with reduced ejection fraction (HFrEF) and those with heart failure with preserved ejection fraction (HFpEF). Recently the utility of LVEF as the major phenotypic determinant of heart failure has been challenged based on its load dependency and measurement variability. We review the history of the development and adoption of LVEF as a critical measurement of LV function and structure and demonstrate that, in chronic heart failure, load dependency is not an important practical issue, and we provide hemodynamic and molecular biomarker evidence that LVEF is superior or equal to more unwieldy methods of identifying phenotypes of ventricular remodeling. We conclude that, because it reliably measures both left ventricular function and structure, LVEF remains the best current method of assessing pathologic remodeling in heart failure in both individual clinical and multicenter group settings. Because of the present and future importance of left ventricular phenotyping in heart failure, LVEF should be measured by using the most accurate technology and methodologic refinements available, and improved characterization methods should continue to be sought.

Prognostic implications of left ventricular global longitudinal strain in heart failure patients with narrow QRS complex treated with cardiac resynchronization therapy: a subanalysis of the randomized EchoCRT trial

Aim

Left ventricular (LV) global longitudinal strain (GLS) reflects LV systolic function and correlates inversely with the extent of LV myocardial scar and fibrosis. The present subanalysis of the Echocardiography Guided CRT trial investigated the prognostic value of LV GLS in patients with narrow QRS complex.

Methods and results

Left ventricular (LV) global longitudinal strain (GLS) was measured on the apical 2-, 4- and 3-chamber views using speckle tracking analysis. Measurement of baseline LV GLS was feasible in 755 patients (374 with cardiac resynchronization therapy (CRT)-ON and 381 with CRT-OFF). The median value of LV GLS in the overall population was 7.9%, interquartile range 6.2-10.1%. After a mean follow-up period of 19.4 months, 95 patients in the CRT-OFF group and 111 in the CRT-ON group reached the combined primary endpoint of all-cause mortality and heart failure hospitalization. Each 1% absolute unit decrease in LV GLS was independently associated with 11% increase in the risk to reach the primary endpoint (Hazard ratio 1.11; 95% confidence interval 95% 1.04-1.17, P < 0.001), after adjusting for ischaemic cardiomyopathy and randomization treatment among other clinically relevant variables. When categorizing patients according to quartiles of LV GLS, the primary endpoint occurred more frequently in patients in the lowest quartile (<6.2%) treated with CRT-ON vs. CRT-OFF (45.6% vs. 28.7%, P = 0.009) whereas, no differences were observed in patients with LV GLS ≥6.2% treated with CRT-OFF vs. CRT-ON (23.7% vs. 24.5%, respectively; P  = 0.62).

Conclusion

Low LV GLS is associated with poor outcome in heart failure patients with QRS width <130 ms, independent of randomization to CRT or not. Importantly, in the group of patients with the lowest LV GLS quartile, CRT may have a detrimental effect on clinical outcomes.

Specific circulating microRNAs display dose-dependent responses to variable intensity and duration of endurance exercise

Circulating microRNAs (c-miRNAs), plasma-based noncoding RNAs that control posttranscriptional gene expression, mediate processes that underlie phenotypical plasticity to exercise. The relationship and biological relevance between c-miRNA expression and variable dose exercise exposure remains uncertain. We hypothesized that certain c-miRNAs respond to changes in exercise intensity and/or duration in a dose-dependent fashion. Muscle release of such c-miRNAs may then deplete intracellular stores, thus facilitating gene reprogramming and exercise adaptation. To address these hypotheses, healthy men participated in variable intensity ( n = 12, 30 × 1 min at 6, 7, and 8 miles/h, order randomized) and variable duration ( n = 14, 7 × 1 mile/h for 30, 60, and 90 min, order randomized) treadmill-running protocols. Muscle-enriched c-miRNAs (i.e., miRNA-1 and miRNA-133a) and others with known relevance to exercise were measured before and after exercise. c-miRNA responses followed three profiles: 1) nonresponsive (miRNA-21 and miRNA-210), 2) responsive to exercise at some threshold but without dose dependence (miRNA-24 and miRNA-146a), and 3) responsive to exercise with dose dependence to increasing intensity (miRNA-1) or duration (miRNA-133a and miRNA-222). We also studied aerobic exercise-trained mice, comparing control, low-intensity (0.5 km/h), or high-intensity (1 km/h) treadmill-running protocols over 4 wk. In high- but not low-intensity-trained mice, we found increased plasma c-miR-133a along with decreased intracellular miRNA-133a and increased serum response factor, a known miR-133a target gene, in muscle. Characterization of c-miRNAs that are dose responsive to exercise in humans and mice supports the notion that they directly mediate physiological adaptation to exercise, potentially through depletion of intracellular stores of muscle-specific miRNAs. NEW & NOTEWORTHY In this study of humans and mice, we define circulating microRNAs in plasma that are dose responsive to exercise. Our data support the notion that these microRNAs mediate physiological adaptation to exercise potentially through depletion of intracellular stores of muscle-specific microRNAs and releasing their inhibitory effects on target gene expression.

Pharmacological Inhibition of mTOR Kinase Reverses Right Ventricle Remodeling and Improves Right Ventricle Structure and Function in Rats

Pulmonary arterial hypertension (PAH) is characterized by pulmonary vascular remodeling, increased pulmonary artery (PA) pressure, right-heart afterload and death. Mechanistic target of rapamycin (mTOR) promotes smooth muscle cell proliferation, survival, and pulmonary vascular remodeling via two functionally distinct mTOR complexes (mTORCs)-1 (supports cell growth) and -2 (promotes cell survival), and dual mTORC1/mTORC2 inhibition selectively induces pulmonary arterial hypertension PA vascular smooth muscle cell apoptosis and reverses pulmonary vascular remodeling. The consequences of mTOR inhibition on right ventricle (RV) morphology and function are not known. Using SU5416/hypoxia rat model of pulmonary hypertension (PH), we report that, in contrast to activation of both mTORC1 and mTORC2 pathways in small remodeled PAs, RV tissues had predominant up-regulation of mTORC1 signaling accompanied by cardiomyocyte and RV hypertrophy, increased RV wall thickness, RV/left ventricle end-diastolic area ratio, RV contractility and afterload (arterial elastance), and shorter RV acceleration time compared with controls. Treatment with mTOR kinase inhibitor, PP242, at Weeks 6-8 after PH induction suppressed both mTORC1 and mTORC2 in small PAs, but only mTORC1 signaling in RV, preserving basal mTORC2-Akt levels. Vehicle-treated rats showed further PH and RV worsening and profound RV fibrosis. PP242 reversed pulmonary vascular remodeling and prevented neointimal occlusion of small PAs, significantly reduced PA pressure and pulmonary vascular resistance, reversed cardiomyocyte hypertrophy and RV remodeling, improved max RV contractility, arterial elastance, and RV acceleration time, and prevented development of RV fibrosis. Collectively, these data show a predominant role of mTORC1 versus mTORC2 in RV pathology, and suggest potential attractiveness of mTOR inhibition to simultaneously target pulmonary vascular remodeling and RV dysfunction in established PH.