Myosin Light Chain Phosphatase Plays an Important Role in Cardiac Fibrosis in a Model of Mineralocorticoid Receptor-Associated Hypertension.

BACKGROUND: Myosin phosphatase targeting subunit 2 (MYPT2) is an important subunit of cardiac MLC (myosin light chain) phosphatase, which plays a crucial role in regulating the phosphorylation of MLC to phospho-MLC (p-MLC). A recent study demonstrated mineralocorticoid receptor-related hypertension is associated with RhoA/Rho-associated kinase/MYPT1 signaling upregulation in smooth muscle cells. Our purpose is to investigate the effect of MYPT2 on cardiac function and fibrosis in mineralocorticoid receptor-related hypertension. METHODS AND RESULTS: HL-1 murine cardiomyocytes were incubated with different concentrations or durations of aldosterone. After 24-hour stimulation, aldosterone increased CTGF (connective tissue growth factor) and MYPT2 and decreased p-MLC in a dose-dependent manner. MYPT2 knockdown decreased CTGF. Cardiac-specific MYPT2-knockout (c-MYPT2-/-) mice exhibited decreased type 1 phosphatase catalytic subunit ß and increased p-MLC. A disease model of mouse was induced by subcutaneous aldosterone and 8% NaCl food for 4 weeks after uninephrectomy. Blood pressure elevation and left ventricular hypertrophy were observed in both c-MYPT2-/- and MYPT2+/+ mice, with no difference in heart weights or nuclear localization of mineralocorticoid receptor in cardiomyocytes. However, c-MYPT2-/- mice had higher ejection fraction and fractional shortening on echocardiography after aldosterone treatment. Histopathology revealed less fibrosis, reduced CTGF, and increased p-MLC in c-MYPT2-/- mice. Basal global radial strain and global longitudinal strain were higher in c-MYPT2-/- than in MYPT2+/+ mice. After aldosterone treatment, both global radial strain and global longitudinal strain remained higher in c-MYPT2-/- mice compared with MYPT2+/+ mice. CONCLUSIONS: Cardiac-specific MYPT2 knockout leads to decreased myosin light chain phosphatase and increased p-MLC. MYPT2 deletion prevented cardiac fibrosis and dysfunction in a model of mineralocorticoid receptor-associated hypertension.

Prognostic Impact of Prehospital Simple Risk Index in Patients With ST-Elevation Myocardial Infarction.

BACKGROUND: The simple risk index recorded in the emergency room (ER-SRI), which is calculated using the formula (heart rate × [age / 10]2) / systolic blood pressure, was shown to be able to stratify the prognosis in ST-elevation myocardial infarction (STEMI) patients. However, the prognostic impact of the prehospital simple risk index (Pre-SRI) remains unknown.Methods and Results: This study enrolled 2,047 STEMI patients from the Mie Acute Coronary Syndrome (ACS) registry. Pre-SRI was calculated using prehospital data and ER-SRI was calculated using emergency room data. The primary endpoint was 30-day all-cause mortality. The cut-off values of Pre-SRI and ER-SRI for predicting 30-day mortality were 34.8 and 34.1, with accuracies of 0.816 and 0.826 based on receiver operating characteristic analyses (P<0.001 for both). There was no difference in the accuracy of the 2 indices. Multivariate Cox regression analysis demonstrated that a High Pre-SRI (≥34) was a significant independent predictor of 30-day mortality. With combined Pre-SRI and ER-SRI assessment, patients with High Pre-SRI/High ER-SRI showed significantly higher mortality than those with High Pre-SRI/Low ER-SRI, Low Pre-SRI/High ER-SRI, and Low Pre-SRI/Low ER-SRI (P<0.001). The addition of High Pre-SRI to High ER-SRI showed incremental prognostic value of the Pre-SRI. CONCLUSIONS: Pre-SRI can identify high-risk STEMI patients at an early stage and combined assessment with Pre-SRI and ER-SRI could be of incremental prognostic value for risk stratification in STEMI patients.

Different Types of Myocardial Injury due to the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Omicron Variant.

Coronavirus disease 2019 (COVID-19) associated myocardial injury was caused by various mechanisms. We herein describe 2 cases presenting different types of myocardial injury due to Omicron variant. In both patients, diffuse reduced left ventricular (LV) wall motion in transthoracic echocardiography, electrocardiographic abnormality, and elevated myocardial enzymes were demonstrated. In addition, cardiovascular magnetic resonance (CMR) findings fulfilled the 2018 Lake Louise Criteria (LLC) for myocarditis. However, histological findings in 1 patient showed inflammatory cell infiltration with myocyte degeneration, while those in the other showed interstitial edema without inflammatory cell infiltration. Histological findings were crucial for a differential diagnosis of myocardial injury due to Omicron variant.

Prognostic Impact of Peak Aortic Jet Velocity on Patients With Acute Myocardial Infarction.

BACKGROUND: Aortic valve stenosis (AS) leads to increased cardiovascular mortality and morbidity, and recent studies reported that even mild-to-moderate AS was associated with poor prognosis in the general population. This study investigated the prognostic impact of mild or moderate AS, defined as 2.0 m/s ≤ peak aortic jet velocity (Vmax) ≤3.9 m/s using echocardiography in acute myocardial infarction (AMI) patients.Methods and Results: This study enrolled 3,049 AMI patients using data from the Mie ACS registry. Patients were divided into 2 groups according to Vmax: Group 1: Vmax <2.0 m/s and/or visually intact aortic valve in which all 3 leaflets are fully and evenly open; Group 2: 2.0 m/s ≤ Vmax ≤ 3.9 m/s. There were 2,976 patients in Group 1and 73 patients in Group 2. The Group 2 patients were older, had a higher percentage of males and had lower body mass index and Killip ≥2 than the Group 1 patients. Angiographic data, door-to-balloon time, and mechanical support were not different between the 2 groups. The Group 2 patients demonstrated a significantly higher all-cause mortality rate (P<0.01) and composite of cardiovascular death and heart failure hospitalization (P<0.01), and Kaplan-Meier analysis showed the same tendency in propensity score-matched patients. CONCLUSIONS: The present study revealed that mild or moderate AS based on Vmax is associated with poor prognosis following AMI.

Peripartum Mid-Ventricular-Type Takotsubo Cardiomyopathy After Cesarean Delivery.

There are several causes of heart failure during pregnancy and the peripartum period, which include peripartum cardiomyopathy, Takotsubo cardiomyopathy or stress cardiomyopathy, exacerbation of a preexisting cardiomyopathy, and acute myocarditis. It is important to determine the cause of the heart failure as the medical treatment may be different based on the diagnosis. However, it has been sometimes challenging to diagnose the cause because of the limited diagnostic tools, especially in pregnant women. Cardiac MRI can characterize myocardial injury and can be used to track the changes in myocardial tissue. We herein report a 35-year-old woman diagnosed with peripartum mid-ventricular-type Takotsubo cardiomyopathy, who was referred to our hospital due to worsening dyspnea the day after cesarean delivery. On admission, electrocardiography showed sinus tachycardia and poor progression of R waves in the precordial leads. Bedside echocardiography revealed severe hypokinesis in the mid- and apical left ventricle (LV) with a LV ejection fraction of 20%. Cardiac catheterization showed normal coronary arteries, and myocardial biopsy revealed contraction band necrosis. On acute phase (Day 4), cardiac MRI showed prolonged native T1 and T2, and severe hypokinesis and decreased regional longitudinal peak strain in the mid-anterior LV wall. During the 1st week, precordial ST fluctuation was observed, and LV wall motion had gradually recovered. Repeat cardiac MRI revealed normalized LV wall motion and shortened values for global native T1 and T2. Thus, she was diagnosed with peripartum Takotsubo cardiomyopathy. Serial cardiac MRI may be able to differentiate Takotsubo cardiomyopathy during pregnancy and the peripartum period from other preexisting cardiomyopathies.

Comparison of haemodynamic response to muscle reflex in heart failure with reduced vs. preserved ejection fraction.

AIMS: Isometric handgrip (IHG) training reduces the blood pressure in patients with hypertension. It is unclear how IHG exercise affects the haemodynamics and cardiovascular function through the muscle reflex in patients with heart failure (HF) with reduced (HFrEF) and preserved ejection fraction (HFpEF). METHODS AND RESULTS: Twenty patients (HFrEF: n = 10, HFpEF: n = 10) underwent left ventricular (LV) pressure-volume assessments using a conductance catheter and microtip manometer to evaluate haemodynamics, LV and arterial function, and LV-arterial coupling during 3 min of IHG at 30% of maximal voluntary contraction (MVC), followed by 3 min of post-exercise circulatory arrest (PECA). Three minutes of IHG exercise produced significant and modest increases in the heart rate (HR) and LV end-systolic pressure (LVESP), respectively, in both HFpEF and HFrEF groups. In HFrEF, the increase in LVESP was caused by the variable increase in effective arterial elastance (Ea), which was counterbalanced by the increase in LV end-systolic elastance (Ees), resulting in a maintained Ees/Ea. In HFpEF, the increase in LVESP was not accompanied by changes in Ea, Ees, Ees/Ea, or LV end-diastolic pressure. LVESP during PECA was not maintained in HFpEF, suggesting smaller metabo-reflex activity in HFpEF. CONCLUSIONS: The IHG exercise used in this study may increase the LVESP and LVEDP without detrimental effects on cardiac function or ventricular-arterial coupling, especially in HFpEF patients. The effects of IHG exercise on haemodynamics and ventricular-arterial coupling may be affected by the patient background and the type and intensity of the exercise.

Pathological Q-Waves With Coronary Artery Spasm.

This case highlights the diagnostic challenge associated with myocarditis, especially when accompanied by coronary spasm. Any coronary spasm with hemodynamic instability and/or an inexplicable widespread electrocardiogram should alert the clinician to the possibility of fulminant myocarditis and the necessity of endomyocardial biopsy for treatment decisions. (Level of Difficulty: Beginner.).

Serial cardiac magnetic resonance imaging in wet beriberi.

A 69-year-old woman with previous pancreaticoduodenectomy was admitted for evaluation of chest discomfort on effort and leg edema for a few months. Oral flosemide before admission for 1 week failed to relieve her symptoms. Her blood pressure was 105/51 mmHg and heart rate was 76 beats/min. Chest X-ray revealed an enlarged heart and mild pulmonary congestion. Echocardiography demonstrated normal left ventricular ejection fraction and diastolic dysfunction with no left ventricular hypertrophy. Cardiac catheterization showed normal coronary arteries, high cardiac index, and elevated intracardial pressures. Myocardial biopsy from the right ventricular septum revealed nearly normal findings. Cardiac magnetic resonance imaging (CMRI) showed both ventricles enlarged and increased global extracellular volume fraction (ECV) of 37%, but normal native T1 and T2 values. As she had pancreaticoduodenectomy, beriberi was suspected. Vitamin B1 significantly increased urine output and lowered intracardiac pressures and cardiac index. After 3 months of vitamin B1, CMRI exhibited that the right ventricle had decreased in size and the global ECV value had been lowered. Our case highlights that chronic beriberi may be associated with little myocardial damage. The increased ECV suggests that the diffuse expansion of extracellular space unrelated to myocardial edema might have been reversed by vitamin B1treatment. Morphological changes in the ventricles and myocardial damage by wet beriberi can be demonstrated by CMRI. .

Mechanisms and prediction of short-term natriuretic effect of sodium-glucose cotransporter 2 inhibitor in heart failure patients coexisting type 2 diabetes mellitus.

The mechanisms of the diuretic effect of sodium-glucose cotransporter 2 (SGLT2) inhibitor and its predictors in heart failure (HF) patients with coexisting type 2 diabetes mellitus (T2DM) remain under investigation. A total of 40 hospitalized HF patients with T2DM (68 ± 13 years old, male gender 63%) were prospectively enrolled and received ipragliflozin at a dose of 50 mg once daily after breakfast for at least 4 consecutive days. They underwent first-morning blood and urine tests, and 24-h urine tests before and after short-term ipragliflozin therapy. Daily urine volume significantly increased from 1365 ± 511 mL/day on day 0 to 1698 ± 595 mL/day on day 3 (P < 0.001), which resulted in significant decreases in body weight and plasma brain natriuretic peptide level. Changes in 24-h urine volume were strongly and independently correlated with changes in 24-h urine sodium excretion (r = 0.80, P < 0.001), but was not significantly correlated with those in 24-h urine sugar excretion (r = 0.29, P = 0.07). Lower concentration of first-morning urine sodium and higher loop diuretic dosage before ipragliflozin therapy were associated with urine volume increment with ipragliflozin therapy, and former retained its independent predictor (Odds ratio 0.96, 95% CI 0.93-0.99, P = 0.02). First-morning urine sodium ≤ 53 mEq/L and baseline loop diuretics ≥ 20 mg/day predicted increased urine volume on day 3 with high diagnostic accuracy. Ipragliflozin has acute natriuretic activity, and first-morning urine sodium and baseline dosage of loop diuretics strongly predicted the diuretic effects. Ipragliflozin therapy may restore responsiveness to loop diuretics in symptomatic HF patients with T2DM.

Effects of sitagliptin on exercise capacity and hemodynamics in patients with type 2 diabetes mellitus and coronary artery disease.

Sitagliptin attenuates left ventricular (LV) dysfunction and may improve oxygen uptake in animals. The effects of sitagliptin on oxygen uptake (VO2) and exercise hemodynamics have been unclear in patients with type 2 diabetes mellitus (T2DM) and coronary artery disease (CAD). Thirty patients with T2DM and CAD were randomized into a sitagliptin (50 mg/day) or voglibose (0.6 mg/day) group. Patients underwent maximal cardiopulmonary exercise testing. VO2 and hemodynamics were evaluated at rest, anaerobic threshold and peak exercise. Resting LV diastolic function (E', peak early diastolic mitral annular velocity) and geometry were evaluated by echocardiography, and endothelial function by reactive hyperemia peripheral arterial tonometry. A total of 24 patients (69 ± 9 years) completed 6 months of intervention. Peak VO2 in the sitagliptin and voglibose groups (25.3 ± 7.3 vs. 24.0 ± 7.4, 22.7 ± 4.8 vs. 22.1 ± 5.2 ml/kg/min) was slightly decreased after 6 months (time effect p = 0.051; group × time effect p = 0.49). No effects were observed on LV ejection fraction, E', or reactive hyperemia index in either group. Heart rate during exercise was unaffected in both groups. Systolic blood pressure was unchanged by sitagliptin at rest and during exercise, but slightly lowered by voglibose at anaerobic threshold and peak exercise. In patients with T2DM and CAD, sitagliptin had little effect on resting LV and arterial function, exercise capacity, or exercise hemodynamics. Further studies need to be conducted with more patients as the number of the patients in this study was limited.

Effect of Sitagliptin on Coronary Flow Reserve Assessed by Magnetic Resonance Imaging in Type 2 Diabetic Patients With Coronary Artery Disease.

BACKGROUND: The present study was conducted to assess the cardiovascular effects of dipeptidyl peptidase-4 inhibitors (DPP4i) on coronary flow reserve (CFR), left ventricular (LV) function and endothelial function of the peripheral artery by comparison with those of α-glucosidase inhibitors (αGI) in patients with type 2 diabetes mellitus (T2DM) and coronary artery disease (CAD).Methods and Results:We randomly assigned 30 patients with T2DM and CAD to receive either sitagliptin or voglibose, and 28 patients (age 69±9 years, 75% male, hemoglobin A1c [HbA1c] 6.62±0.48%) completed the study (14 in each group). CFR and LV function, assessed by cardiac magnetic resonance imaging, and endothelial function, assessed by reactive hyperemia peripheral arterial tonometry (RH-PAT), were measured at baseline and 24 weeks after treatment. Clinical and laboratory parameters, including HbA1c level, plasma active glucagon-like peptide-1 concentrations, and biomarkers of inflammation, were unchanged in both groups after 24 weeks of treatment. CFR were unchanged in both the αGI group (3.01±0.98 at baseline and 3.06±0.8 after treatment, P=NS) and the DPP4i group (4.29±2.04 at baseline and 3.63±1.31 after treatment, P=NS), with no interaction effect. LV functional parameters and the reactive hyperemia index also remained unchanged after the 24-week treatment. CONCLUSIONS: DPP4i did not improve CFR, LV function or endothelial function of the peripheral artery in patients with relatively well-controlled T2DM and CAD.

Postdischarge Light-Intensity Physical Activity Predicts Rehospitalization of Older Japanese Patients With Heart Failure.

PURPOSE: Regular physical activity (PA) is recommended for patients with heart failure (HF). However, the clinical and social characteristics of older HF patients with low-level PA and the impact of light-intensity PA on 6-mo postdischarge adverse cardiovascular events are still unclear. METHODS: Forty-one older patients who had been admitted because of decompensated HF (American College of Cardiology [ACC]/American Heart Association [AHA] HF classification stage C/D: 76 ± 5 y) were prospectively enrolled. Light-intensity (1.5-2.9 metabolic equivalents [METs]) and moderate-intensity (≥3 METs) PAs were determined by triaxial accelerometry for at least 7 d postdischarge. Six-min walk distance and 36-item Short Form questionnaire (SF-36) score were evaluated at discharge. HF patients were stratified into either the HFPA-high or HFPA-low group according to median daily PA. Twenty-nine older ACC/AHA stage A/B outpatients (HF-risk), who were at risk for HF but no symptoms of HF had developed, also completed these assessments. Clinical predictors for 6-mo postdischarge HF rehospitalization were assessed. RESULTS: HF patients were anemic and less active. HFPA-low patients were less likely to engage in household work, took fewer steps, and had less light and moderate-intensity PA than HFPA-high patients. There were no differences in 6-min walk distance, SF-36 score, or left ventricular ejection fraction between HFPA-low and HFPA-high patients. Postdischarge PA, especially light-intensity PA, was independently associated with HF rehospitalization. CONCLUSION: Low volume of PA postdischarge, especially at 1.5 to 2.9 METs, predicts 6-mo postdischarge HF rehospitalization in older HF patients.

Effect of Anemia on Cardiovascular Hemodynamics, Therapeutic Strategy and Clinical Outcomes in Patients With Heart Failure and Hemodynamic Congestion.

BACKGROUND: We investigated the effect of anemia on cardiovascular hemodynamics, therapeutic strategies and clinical outcomes in heart failure (HF) patients.Methods and Results:We divided 198 consecutive HF patients who underwent right heart catheterization before in-hospital HF treatment into 2 groups according to the presence or absence of hemodynamic congestion (HC: mean pulmonary capillary wedge pressure ≥15 mmHg and/or mean right atrial pressure ≥10 mmHg). The hemoglobin level correlated with the cardiac index (CI) and systemic vascular resistance index (SVRI) (r=-0.34 and 0.42, P<0.05, respectively), and was the strongest contributor of SVRI only in the HC group. Anemic patients more frequently required intravenous inotropic support despite having higher CI and lower SVRI than non-anemic patients in the HC group. The novel hemodynamic subsets based on mean right atrial pressure and estimated left ventricular stroke work index but not Forrester subsets appropriately predicted the need for intravenous inotropic support. The probability of hospitalization for worsening HF during 2-year follow-up period was significantly higher in anemic patients than in non-anemic patients in the HC group. CONCLUSIONS: Anemia had a direct effect on cardiovascular hemodynamics and thus can confound therapeutic planning in HF patients with HC. The novel hemodynamic subsets can be applied in daily clinical practice regardless of the presence or absence of anemia.

A Survival Case of Fulminant Right-Side Dominant Eosinophilic Myocarditis.

A 59-year-old Japanese woman was admitted to a nearby hospital with dyspnea and general malaise. Transthoracic echocardiography revealed right ventricular (RV) dilatation with severely reduced systolic function and leftward shift of the intraventricular septum. She was initially diagnosed with acute right heart failure, and fell into cardiogenic shock requiring an intra-aortic balloon pump and inotropic agents. An endomyocardial biopsy (EMB) demonstrated extensive interstitial edema, infiltration of inflammatory cells including numerous eosinophils, and myocytolysis with eosinophil degranulation. She was histologically diagnosed with eosinophilic myocarditis. Steroid pulse therapy was initiated, and her hemodynamic status improved along with dramatic recovery of the RV function. EMB 6 days after the initiation of steroid pulse therapy showed the disappearance of infiltration and degranulation of eosinophils, although lymphocytic infiltration still remained. Positron emission tomography-computed tomography (PET/CT) 23 days after steroid pulse therapy showed an increased 18F-FDG uptake in the intraventricular septum and left ventricle, suggesting persistent myocardial inflammation. She was then treated with a maintenance dose of prednisolone. She became free of symptoms and follow-up echocardiography showed normal cardiac function 3 months after the initiation of corticosteroid treatment. In addition, EMB and PET/CT showed no inflammation. This is the first case report of fulminant and right-sided dominant eosinophilic myocarditis successfully treated with corticosteroid.

Fulminant Myocarditis With Prolonged Active Lymphocytic Infiltration After Hemodynamic Recovery.

Fulminant myocarditis is a highly mortal syndrome. Meanwhile, the clinical course in surviving patients is generally self-limiting. This is a rare case of fulminant myocarditis with prolonged lymphocytic infiltration after hemodynamic recovery. A 64-year-old man was diagnosed with fulminant myocarditis and required intensive care with veno-arterial extracorporeal membrane oxygenation. Left ventricular function gradually improved but complete atrioventricular block (CAVB) persisted. Follow-up endomyocardial biopsies (EMBs) showed prolonged active infiltration of lymphocytes along with 18F-FDG uptake in 18F-FDG PET/CT until about 70 days after the onset. Therefore, he underwent immunosuppressive therapy for 3 months. Follow-up EMB revealed no evidence of infiltration of lymphocytes and no abnormal 18F-FDG uptake despite irreversible CAVB. Although repeated EMB and 18F-FDG PET/CT was not a standard strategy, it played an important role in the treatment decision in the present case.