Mitochondrial Structural Abnormalities and Cardiac Reverse Remodeling in Patients With Systolic Dysfunction.

BACKGROUND: Mitochondrial dysfunction in the heart is associated with the development of heart failure (HF). However, the clinical consequences of mitochondrial structural abnormalities in patients with HF remain unexplored. METHODS AND RESULTS: Ninety-one patients with left ventricular (LV) systolic dysfunction who underwent endomyocardial biopsy (EMB) were enrolled in the study. Myocardial specimens were obtained from the right ventricular septum. Specimens were characterized using electron microscopy to assess mitochondrial size, outer membrane disruption, and cristae disorganization. The primary endpoint was a composite of cardiovascular death and unplanned hospitalization for HF. Patients were classified into LV reverse remodeling (LVRR)-positive (n=52; 57.1%) and LVRR-negative (n=39; 42.9%) groups. Cristae disorganization was observed in 21 (23.1%) patients: 6 (11.5%) in the LVRR-positive group and 15 (38.5%) in the LVRR-negative group (P=0.005). During the 1-year post-EMB observation period, 16 patients (17.6%) met the primary endpoint, with 2 (2.2%) cardiovascular deaths and 14 (15.4%) HF hospitalizations. Cristae disorganization (P=0.002) was significantly associated with the endpoints, independent of age (P=0.115), systolic blood pressure (P=0.004), B-type natriuretic peptide level (P=0.042), and mitral regurgitation (P=0.003). CONCLUSIONS: We classified mitochondrial structural abnormalities and showed that cristae disorganization was associated with LVRR and worse prognosis. These findings may affect the management of patients with HF and systolic dysfunction who undergo EMB.

Efficacy of Low-Dose Isoproterenol Infusion for the Exclusion of a Left Atrial Appendage Thrombus in Patients With Dense Spontaneous Echo Contrast Caused by Atrial Fibrillation.

BACKGROUND: In patients with atrial fibrillation (AF) and severe blood stasis in the left atrial appendage (LAA), dense spontaneous echo contrast (SEC) disturbs the distinct visualization of the LAA interior, thus making thrombus diagnosis inconclusive. We aimed to prospectively assess the efficacy and safety of a protocol for a low-dose isoproterenol (ISP) infusion to reduce SEC to exclude an LAA thrombus.Methods and Results: We enrolled 17 patients with AF and dense SEC (Grade 4 or sludge). ISP was infused with gradually increasing doses of 0.01, 0.02, and 0.03 µg/kg/min at 3-min intervals. After increasing the dose to 0.03 µg/kg/min for 3 min, or when the LAA interior was visible, the infusion was terminated. We reassessed the SEC grade, presence of an LAA thrombus, LAA function, and left ventricular ejection fraction (LVEF) within 1 min of ISP termination. Compared with baseline, ISP significantly increased LAA flow velocity, the LAA emptying fraction, LAA wall velocities, and LVEF (all P<0.01). ISP administration significantly reduced the SEC grade (median) from 4 to 1 (P<0.001). The SEC grade decreased to ≤2 in 15 (88%) patients, and the LAA thrombus was excluded. There were no adverse events. CONCLUSIONS: Low-dose ISP infusion may be effective and safe to reduce SEC and exclude an LAA thrombus by improving LAA function and LVEF.

Long-QT Syndrome with Peripartum Cardiomyopathy Causing Fatal Ventricular Arrhythmia after Delivery.

Although rare, long QT syndrome (LQTS) and peripartum cardiomyopathy (PPCM) are the major causes of maternal cardiovascular death. We herein present a case study of a 23-year-old woman with LQTS, pregnancy-induced hypertension, and PPCM. During the postpartum period, her left ventricular systolic function had severely decreased, requiring the administration of loop diuretics. Diuretics cause several changes in the circulating blood volume, electrolyte balance, and hormonal status during pregnancy, delivery, and the peripartum period. Extreme QTc prolongation and fatal ventricular arrhythmia require frequent defibrillation. For the patient in this study, we corrected her electrolyte abnormality, and eventually, we controlled the arrhythmia by administering a ß-blocker and Na-channel blocker. Although the arrhythmia subsided, she continued on medication after discharge to prevent the recurrence of fatal arrhythmia. In conclusion, close attention should be paid to patients with LQTS, especially when some changes that may lead to QTc prolongation could occur during the peripartum period.

Longitudinal Changes in Natriuretic Peptides and Reverse Cardiac Remodeling in Patients with Heart Failure Treated with Sacubitril/Valsartan Across the Left Ventricular Ejection Traction Spectrum.

Sacubitril/valsartan improves outcomes in patients with heart failure (HF) with reduced ejection fraction. However, the relationship between longitudinal changes in natriuretic peptides and echocardiographic parameters in patients with HF treated with sacubitril/valsartan across the left ventricular ejection fraction (LVEF) range is not fully understood.In patients with HF treated with sacubitril/valsartan, comprehensive data on natriuretic peptides, including atrial natriuretic peptide (ANP), N-terminal pro-brain-type natriuretic peptide (NT-proBNP), BNP, and echocardiography, were measured after 6 months of treatment. We assessed the change in natriuretic peptides and echocardiographic parameters in LVEF classification subgroups.Among 49 patients, the median ANP concentration increased from 55 pg/mL at baseline to 78 pg/mL (P < 0.001). The NT-proBNP concentration decreased from 250 pg/mL to 146 pg/mL (P < 0.001). No significant change was observed in the BNP concentration (P = 0.640). The trajectories of each natriuretic peptide in patients with LVEF > 40% (n = 22) were similar to those in individuals with LVEF ≤ 40% (n = 27). Regardless of LVEF classification, echocardiography at 6 months showed a significant improvement in LVEF, left ventricular end-diastolic volume, and the ratio of early diastolic mitral inflow velocity to early diastolic mitral annulus velocity (E/e'). The reduction in natriuretic peptide concentration was related to LV reverse remodeling and decreased left and right atrial pressures assessed by E/e' and inferior vena cava diameter.Sacubitril/valsartan induced an increase in ANP, a reduction in NT-proBNP, and no change in plasma BNP, regardless of LVEF. It caused LV reverse remodeling, and the natriuretic peptide concentration changes were associated with structural and functional echocardiographic parameters.

Sodium Glucose Co-Transporter 2 Inhibitors Improve Renal Congestion and Left Ventricular Fibrosis in Rats With Hypertensive Heart Failure.

BACKGROUND: Elevated central venous pressure (CVP) in heart failure causes renal congestion, which deteriorates prognosis. Sodium glucose co-transporter 2 inhibitor (SGLT2-i) improves kidney function and heart failure prognosis; however, it is unknown whether they affect renal congestion. This study investigated the effect of SGLT2-i on the kidney and left ventricle using model rats with hypertensive heart failure.Methods and Results: Eight rats were fed a 0.3% low-salt diet (n=7), and 24 rats were fed an 8% high-salt diet, and they were divided into 3 groups of untreated (n=6), SGLT2-i (canagliflozin; n=6), and loop diuretic (furosemide; n=5) groups after 11 weeks of age. At 18 weeks of age, CVP and renal intramedullary pressure (RMP) were monitored directly by catheterization. We performed contrast-enhanced ultrasonography to evaluate intrarenal perfusion. In all high-salt fed groups, systolic blood pressure was elevated (P=0.287). The left ventricular ejection fraction did not differ among high-salt groups. Although CVP decreased in both the furosemide (P=0.032) and the canagliflozin groups (P=0.030), RMP reduction (P=0.003) and preserved renal medulla perfusion were only observed in the canagliflozin group (P=0.001). Histological analysis showed less cast formation in the intrarenal tubule (P=0.032), left ventricle fibrosis (P<0.001), and myocyte thickness (P<0.001) in the canagliflozin group than in the control group. CONCLUSIONS: These results suggest that SGLT2-i causes renal decongestion and prevents left ventricular hypertrophy, fibrosis, and dysfunction.

Clinical Characteristics of Non-Valvular Atrial Fibrillation Patients With a Large Left Atrial Appendage Ostium-Limiting Percutaneous Closure.

BACKGROUND: The left atrial appendage (LAA) is a therapeutic target for preventing cardioembolic stroke in patients with non-valvular atrial fibrillation (NVAF). A large LAA ostium limits percutaneous LAA closure. This study investigated the characteristics and factors associated with a large LAA ostium in Japanese patients with NVAF.Methods and Results: In 1,102 NVAF patients, the maximum LAA diameter was measured using transesophageal echocardiography (TEE). A large LAA ostium was defined by a maximum diameter of >30 mm. Forty-four participants underwent repeated TEEs, and changes in LAA size under lasting AF were assessed. A large LAA ostium was observed in 3.1% of all participants and 8.9% of patients with long-standing persistent AF (LSAF). The large LAA group had greater CHA2DS2-VASc (P=0.024) and HAS-BLED scores (P=0.046) and a higher prevalence of LAA thrombus (P=0.004) than did the normal LAA group. LSAF, moderate or severe mitral regurgitation, left atrial volume ≥42 mL/m2, E/E' ratio ≥9.5, and left ventricular mass ≥85 mg/m2were independently associated with a large LAA ostium (P<0.001, P<0.001, P=0.009, P=0.009, and P=0.032, respectively). In 44 patients with lasting AF, the LAA ostial diameter increased over time (P<0.001). CONCLUSIONS: NVAF patients with a large LAA ostium may have a higher risk of stroke and bleeding. LSAF and factors leading to LA overload may be closely associated with LAA ostial dilatation and can promote it.

Right bundle branch block and risk of cardiovascular mortality: the Ibaraki Prefectural Health Study.

Historically, a right bundle branch block has been considered a benign finding in asymptomatic individuals. However, this conclusion is based on a few old studies with small sample sizes. We examined the association between a complete right bundle branch block (CRBBB) and subsequent cardiovascular mortality in the general population in Japan. In this large community-based cohort study, data of 90,022 individuals (mean age, 58.5 ± 10.2 years; 66.2% women) who participated in annual community-based health check-ups were assessed. Subjects were followed up from 1993 to the end of 2016. Cox proportional hazards' models and log-rank tests were used for the data analysis. CRBBB was documented in 1,344 participants (1.5%). Among all included participants, CRBBB was associated with an increased risk of cardiovascular mortality after adjustment for all potential confounders (hazard ratio [HR] 1.21; 95% confidence interval [CI] 1.06-1.38). The increased risk of cardiovascular mortality was particularly evident in women aged < 65 years (HR 2.00; 95% CI 1.34-2.98) and men aged ≥ 65 years (HR 1.28; 95% CI 1.06-1.55). CRBBB is associated with an increased risk of cardiovascular mortality in women aged < 65 years and men aged ≥ 65 years. Clinicians should be aware of the presence of CRBBB in young women and elderly men, even if they exhibit no symptoms.

Prognostic Impact of Changes in Intrarenal Venous Flow Pattern in Patients With Heart Failure.

BACKGROUND: It remains unclear whether intrarenal venous flow (IRVF) patterns in patients with heart failure (HF) could change over the clinical course, and whether the changes could have a clinical impact. Thus, this study aimed to clarify these characteristics as well as to identify the relation between changes in the IRVF pattern and renal impairment progression. METHODS AND RESULTS: Patients with HF with repetitive IRVF evaluations were enrolled. Doppler waveforms of IRVF were classified into the following 3 flow patterns: continuous, biphasic discontinuous, and monophasic discontinuous. Primary end points included death from cardiovascular diseases and unplanned hospitalization for HF. Finally, 108 patients with adequate images were enrolled. The IRVF in 35 patients (32.4%) shifted to another pattern at the follow-up examinations. The median brain natriuretic peptide level in the continuous flow pattern at follow-up was significantly decreased (183 to 60 pg/mL, P < .001), whereas that of the discontinuous flow pattern at follow-up was increased (from 339 to 366 pg/mL, P = .042) and the estimated glomerular filtration rate was decreased (from 55 to 50 mL/min/1.73 m2, P = .013). A multivariable Cox proportional hazard model analysis revealed that the discontinuous pattern at follow-up (P < .001) and brain natriuretic peptide (P = .021) were significantly associated with the end points, independent of age, estimated glomerular filtration rate, and serum sodium level. CONCLUSIONS: The IRVF pattern could be changed depending on the status of congestion. Persistent or worsened renal congestion, represented by discontinuous flow patterns, during the clinical courses indicated a poor prognosis accompanied by renal impairment in patients with HF.

Clinical impacts of changes of renal function during hospitalization depend on grades of renal dysfunction in acute decompensated heart failure.

Clinical impact of changes of renal function (RF) in heart failure (HF) hospitalization is controversial. This study aimed to clarify whether clinical impact of changes of RF during HF hospitalization depends on the intrinsic RF. In 786 hospitalized HF patients, RF were classified into 3 grades based on estimated glomerular filtration rate (eGFR, mL/min/1.73 m2) at discharge; ≥ 60 (n = 243), < 60 and ≥ 30 (n = 400), and < 30 (n = 143). Increase and decrease of serum creatinine over 0.3 mg/dL during HF hospitalization were defined as worsening renal function (WRF) and improved renal function (IRF), respectively, and remaining subjects were defined as stable RF. The primary endpoint was a composite of cardiovascular death and rehospitalization for HF. In all patients, WRF was not associated with clinical outcomes, although eGFR has a significant association with prognosis. Clinical outcomes did not differ between changes of RF patterns in both preserved and severely impaired RF groups. In contrast, IRF, not WRF, was an independent predictor of clinical outcomes in the moderately impaired RF group (HR 1.965, 95% CI 1.09-3.18, p = 0.01). Only in patients with moderately impaired RF, changes of RF were associated with clinical outcome, and IRF was an independent predictor of clinical outcomes.

Different Impact of Changes in Left Ventricular Ejection Fraction Between Heart Failure Classifications in Patients With Acute Decompensated Heart Failure.

BACKGROUND: Left ventricular ejection fraction (LVEF) can dramatically change when the patient has acute decompensated heart failure (ADHF). We investigated the impact of LVEF and subsequent changes on prognosis in patients with ADHF through a prospective study.Methods and Results: A total of 516 hospitalized patients with ADHF were evaluated. Echocardiography was performed on admission, prior to discharge, and 1 year after discharge. The primary endpoint was a composite of cardiovascular death and hospitalization. In heart failure with reduced EF (HFrEF; LVEF <40%), LVEF did not significantly improve during hospitalization (P=0.348); however, it improved after discharge (P<0.001). In contrast, LVEF improved during hospitalization (P<0.001) in HF with preserved EF (HFpEF; LVEF ≥50%). In HF with mid-range EF (HFmrEF; LVEF 40-49%), LVEF consistently improved throughout the observation period (P<0.001). A multivariable Cox model showed that improved LVEF after discharge was associated with a better outcome in HFrEF (hazard ratio [HR]: 0.951; 95% confidence interval [CI]: 0.928-0.974; P<0.001), while improved LVEF during hospitalization was associated with a better outcome in HFpEF (HR: 0.969; 95% CI: 0.940-0.998; P=0.038). CONCLUSIONS: Improved LVEF after discharge in HFrEF and during hospitalization in HFpEF was associated with a better prognosis in patients with ADHF. Longitudinal improvements in LVEF had different prognostic impact, depending on the HF type by LVEF measurement.

Comparison of effects of aldosterone receptor antagonists spironolactone and eplerenone on cardiovascular outcomes and safety in patients with acute decompensated heart failure.

Differences in the clinical impacts of the aldosterone receptor antagonists spironolactone and eplerenone in patients with heart failure (HF) are unclear. Among 838 prospectively enrolled patients hospitalized for HF, 90 treated with eplerenone were compared with 90 treated with spironolactone. The primary endpoint was a composite of cardiovascular death and hospitalization. A serial evaluation of the clinical parameters was performed 1 year after discharge. The mean dose of spironolactone was 27 ± 8 mg and of eplerenone was 34 ± 15 mg. During follow-up (mean 594 ± 317 days), primary endpoints occurred in 27 patients in the eplerenone group (30.0%) and 25 patients in the spironolactone group (27.8%). There were no significant intergroup differences in the primary endpoint (log-rank, p = 0.956). Serial changes in left ventricular ejection fraction, serum brain natriuretic peptide, systolic blood pressure, and estimated glomerular filtration rate did not differ significantly between groups. Although gynecomastia in men was common in the spironolactone group (p = 0.018), the discontinuation rates due to adverse events were similar in the two groups (p = 0.135). Subgroup analyses suggested that eplerenone was associated with a lower hazard rate of the primary endpoint in female patients (interaction, p = 0.076). Among patients with HF, eplerenone and spironolactone have similar impacts on cardiovascular outcomes and safety.

Assessment of renal congestion in a rat model with congestive heart failure using superb microvascular imaging.

PURPOSE: Renal congestion is a therapeutic target in congestive heart failure. However, its detailed evaluation in a clinical setting is challenging. This study sought to assess renal congestion impairment using superb microvascular imaging (SMI), a simple and accessible method. METHODS: Dahl salt-sensitive rats, used as a model for congestive heart failure, underwent central venous pressure (CVP) measurements. Renal congestion was evaluated through measurements of renal medullary pressure (RMP) and assessment of renal perfusion using contrast-enhanced ultrasonography at both the early (control group) and heart failure phases (HF group). All rats were assessed with SMI. The region of interest (ROI) was set in interlobular vessels, interlobar vessels, and a combination of these areas. The area ratio was calculated from the color pixel count in the ROI divided by the total pixel count in the ROI. Intrarenal perfusion index (IRPI) was defined as (maximum area ratio-minimum area ratio) / maximum area ratio. RESULTS: There were no significant differences in renal function and left ventricular ejection fraction between the two groups. CVP, time-to-peak (TTP) in the medulla, and RMP were higher in the HF group than in the control group. In the HF group, IRPI, evaluated in the interlobular vessels, was significantly higher than in the control group. IRPI was positively correlated with TTP in the medulla (p = 0.028, R = 0.60) and RMP (p < 0.001, R = 0.84), indicating that IRPI reflected renal congestion. CONCLUSIONS: IRPI is a useful tool for assessing renal congestion in rats with congestive heart failure.

Clinical significance of echocardiographic left ventricular hypertrophy for predicting left atrial appendage thrombotic milieu in patients with atrial fibrillation and CHA2DS2-VASc scores of 0-2.

BACKGROUND: The clinical significance of echocardiographic left ventricular hypertrophy (LVH) in risk stratification of left atrial appendage (LAA) thrombogenic milieu, as a surrogate for cardioembolic risk, in patients with atrial fibrillation (AF) and HA2DS2-VASc scores of 0-2 is unknown. METHODS AND RESULTS: We enrolled 707 consecutive patients with AF and CHA2DS2-VASc scores of 0-2 who underwent transesophageal echocardiography. LAA thrombogenic milieu was defined as the presence of a thrombus, severe spontaneous echo contrast, sludge in the LAA, or LAA flow velocity ≤ 20 cm/s. Alongside conventional parameters, longitudinal strain values for the left ventricle (LV) and left atrium were obtained using transthoracic echocardiography. Among the 707 patients, 77 (10.9 %) exhibited LVH. The LVH group exhibited a significantly higher prevalence of LAA thrombogenic milieu than the non-LVH group (32.5 % vs. 2.5 %, p < 0.001). LVH independently associated with LAA thrombogenic milieu after adjusting for clinical factors (including CHA2DS2-VASc score, AF type, and serum brain natriuretic peptide levels) and conventional echocardiographic parameters (including LV ejection fraction, LV end-diastolic volume index, and left atrium volume index) (odds ratio [OR]: 7.54, 95 % confidence interval [CI]: 3.49-16.29, p < 0.001 and OR: 7.16, 95 % CI: 3.26-15.73, p < 0.001, respectively). Moreover, LVH provided incremental value for predicting LAA thrombogenic milieu, even when added to the longitudinal strain of the LV and left atrium reservoir strains (p < 0.001). CONCLUSION: Echocardiographic LVH significantly improves the prediction of LAA thrombogenic milieu, offering potential utility in further cardioembolic risk stratification for patients with AF and CHA2DS2-VASc scores of 0-2.

Additional diagnostic value of electron microscopic examination in endomyocardial biopsy in patients with suspected non-ischemic cardiomyopathy.

BACKGROUND: Electron microscopy enables a finely detailed analysis of ultra-structural features, and hence, it generally has an added diagnostic value to light microscopy alone. However, no studies have verified the additional diagnostic value of electron microscopic examination in patients with suspected non-ischemic cardiomyopathy. METHODS: A total of 294 consecutive patients with non-ischemic cardiomyopathy who underwent endomyocardial biopsy were prospectively enrolled. Patients were divided into three groups according to left ventricular morphology assessed using echocardiography. Myocardial specimens were collected from the right ventricular septum and examined by light microscopy. Electron microscopy was performed subsequently to evaluate the additional diagnostic value. RESULTS: Altogether, 294 patients were analyzed, including 160 (55 %), 96 (33 %), and 35 (12 %) patients who were diagnosed with primary, secondary, and unclassified cardiomyopathy, respectively. In patients with dilated cardiomyopathy-like morphology, the detection rate of disease-specific histological findings was relatively low compared to that in patients with other cardiac morphologies. The additional diagnostic value of electron microscopy was observed in eight patients, including five with Fabry disease, one with cardiac amyloidosis, one with mitochondrial cardiomyopathy, and one with triglyceride deposit cardiomyovasculopathy. Among the 18 cardiac amyloidosis cases, electron microscopy detected amyloid fibrils in all patients, whereas light microscopy could not detect amyloid deposition in 1 patient. Among one of five patients with Fabry disease, light microscopy did not show obvious vacuolated cardiomyocytes, but zebra bodies were detected by electron microscopy, leading to the diagnosis of cardiac Fabry disease. The diagnostic value of electron microscopic examination in patients with cardiac sarcoidosis was not observed. CONCLUSIONS: The additional diagnostic value of electron microscopy was observed in patients with secondary cardiomyopathy, in whom light microscopy did not show disease-specific histological findings. Electron microscopy should be performed in cases where secondary cardiomyopathy is strongly suspected with no disease-specific findings by light microscopy.

Reverse remodeling of the tricuspid valve complex by sinus rhythm restoration after catheter ablation.

BACKGROUND: Atrial fibrillation (AF) can cause right atrium enlargement and structural changes of the tricuspid valve annulus (TVA). The features of the structural changes and benefits obtained from rhythm-control therapy is unknown. OBJECTIVES: We investigated how the TVA changes and whether its size decreases after rhythm-control therapy. METHODS: Multi-detector row computed tomography (MDCT) was performed before and after catheter ablation for AF. TVA morphology and right atrium (RA) volume was evaluated by MDCT. The features of TVA morphology in patients with AF after rhythm-control therapy were analyzed. RESULTS: MDCT was performed in 89 patients with AF. The 3D perimeter was more correlated with diameter in the anteroseptal-posterolateral (AS-PL) direction than in the anterior-posterior direction. Seventy patients showed 3D perimeter reduction owing to rhythm-control therapy and the change was associated with the rate of change in the AS-PL diameter. Rate of change of the 3D perimeter was associated with that of the AS-PL diameter among TVA morphology and RA volume. We divided the subjects into three groups according to the tertiles of the TA perimeter. 3D perimeter in all groups was decreased after rhythm-control therapy. The AS-PL diameter in the 2nd and 3rd tertiles was decreased and increased TVA height in all groups. CONCLUSION: TVA in patients with AF was enlarged and flattened in the early phase, and rhythm-control therapy resulted in reverse remodeling of the TVA and in the reduction of right atrial volume. These results suggest that early AF intervention can lead to the restoration of the TVA structure.

Clinical implications of organ congestion in heart failure patients as assessed by ultrasonography.

In the management of heart failure (HF), decongestion is critical for improving clinical outcomes in addition to patients' symptoms. Although physicians accept this theory, there are no established markers for the achievement of optimal decongestion status. Organ congestion, in particular liver and kidney congestion, has recently attracted substantial attention. Ultrasound methods have been introduced for assessing organ congestion, although this is merely a preliminary step. Here, we review the clinical implications of the assessment of organ congestion by ultrasound.