Association of Atrial Fibrillation Progression With Left Atrial Functional Reserve and Its Reversibility.

BACKGROUND: Atrial fibrillation (AF) progression is closely related to heart failure occurrence, and catheter ablation carries a beneficial effect for heart failure prevention. Recently, particular attention has been given to left atrial (LA) function and functional reserve in the pathogenesis linking AF and heart failure, although its significance and reversibility is not well studied. METHODS AND RESULTS: We prospectively investigated 164 patients with AF with normal left ventricular systolic function and free from heart failure who underwent first catheter ablation and pre-/postprocedural echocardiography. Conventional and speckle-tracking echocardiography were performed at rest and during passive leg lifting to assess LA size, LA reservoir strain (LARS), and functional reserve calculated as passive leg lifting-LARS - rest-LARS. Patients were categorized into 3 AF subtypes: paroxysmal AF (N=95), persistent AF (PeAF; N=50), and long-standing persistent AF (LS-PeAF; N=19). The PeAF and LS-PeAF groups had larger LA size and reduced LARS compared with the paroxysmal AF group (all P<0.05). LA functional reserve was significantly impaired in the LS-PeAF group (P=0.003). In multivariable analysis, LS-PeAF and advanced age were significantly associated with impaired LA functional reserve. Among 149 patients with sinus rhythm 1 to 2 days after catheter ablation, LARS was significantly improved in both PeAF and LS-PeAF groups but was still lower than that in the paroxysmal AF group. Sinus rhythm restoration also led to amelioration of LA functional reserve in patients with LS-PeAF. CONCLUSIONS: AF progression was related to impaired LARS and LA functional reserve, and restoration of sinus rhythm might contribute to early LA reverse remodeling.

Prevalence, Associated Factors, and Echocardiographic Estimation of Left Atrial Hypertension in Patients With Atrial Fibrillation.

Background Elevated left atrial (LA) pressure predisposes individuals to the initiation and persistence of atrial fibrillation (AF), and LA hypertension is associated with AF recurrence after catheter ablation (CA). However, the exact frequency and factors associated with LA hypertension are unknown, and its noninvasive estimation is challenging. This study aimed to investigate the prevalence and determinants of LA hypertension in patients with AF who underwent first CA. Methods and Results We examined 183 patients with AF who underwent conventional and speckle-tracking echocardiography before CA to assess LA size, reservoir strain, and stiffness. Direct LA pressure was measured at the time of CA, and LA hypertension was defined as mean LA pressure >15 mm Hg. Thirty-three (18.0%) patients exhibited LA hypertension. Patients with LA hypertension had a significantly larger LA volume index (40.2 [28.4-52.1] versus 34.1 [26.9-42.4] mL/m2, P=0.025), reduced LA reservoir strain (15.1 [10.4-21.7] versus 22.7 [14.4-32.3] %, P=0.002) and increased LA stiffness (0.69 [0.34-0.99] versus 0.36 [0.24-0.54], P<0.001). Multivariable analyses showed that waist circumference, C-reactive protein level, LA reservoir strain, and LA stiffness were independently associated with LA hypertension (all P<0.05), while LA volume and E/e' ratio were not. Among echocardiographic parameters, receiver operating characteristic curve analysis identified LA stiffness as the best predictor of LA hypertension. Conclusions Approximately 20% of patients with AF who underwent CA had LA hypertension. Central obesity and inflammation might be involved in the pathophysiological mechanisms of LA hypertension, and echocardiography-derived LA stiffness may have clinical utility for the detection of LA hypertension before CA.

Prevalence of glucose metabolism disorders and its association with left atrial remodelling before and after catheter ablation in patients with atrial fibrillation.

AIMS: To investigate the exact prevalence of glucose metabolism disorders, and their impact on left atrial (LA) remodelling and reversibility in patients with atrial fibrillation (AF). METHODS AND RESULTS: We examined 204 consecutive patients with AF who underwent their first catheter ablation (CA). Oral glucose tolerance test was used to evaluate glucose metabolism disorders in 157 patients without known diabetes mellitus (DM). Echocardiography was performed before and 6 months after CA. Oral glucose tolerance test identified abnormal glucose metabolism in 86 patients [11 with newly diagnosed DM, 74 with impaired glucose tolerance (IGT) and 1 with impaired fasting glucose (IFG)]. Ultimately, 65.2% of patients had abnormal glucose metabolism. Diabetes mellitus group had the worst LA reservoir strain and LA stiffness (both P < 0.05), while there was no significant difference in baseline LA parameters between normal glucose tolerance (NGT) group and IGT/IFG group. The prevalence of LA reverse remodelling (≥15% decrease in the LA volume index at 6 months after CA) was significantly higher in NGT group compared with IGT/IFG and DM group (64.1 vs. 38.6 vs. 41.5%, P = 0.006). Both DM and IFG/IGT carry a significant risk of lack of LA reverse remodelling independent of baseline LA size and AF recurrence. CONCLUSION: Approximately 65% of patients with AF who underwent their first CA had abnormal glucose metabolism. Patients with DM had significantly impaired LA function compared with non-DM patients. Impaired glucose tolerance/IFG as well as DM carries significant risk of unfavourable LA reverse remodelling. Our observations may provide valuable information regarding the mechanisms and therapeutic strategies of glucose metabolism-related AF.

Association of arterial properties with left ventricular morphology and function in the community.

OBJECTIVES: Arterial structural and functional remodeling is recognized as a key determinant of incident heart failure, although the contribution of arterial properties on left ventricular (LV) remodeling is not fully studied. Aortic dilatation is an early manifestation of arterial remodeling and estimated pulse wave velocity (ePWV) is emerging as a simple measure of arterial stiffness. This study aimed to characterize the association of aortic size and ePWV with LV morphology and function. METHODS: The study cohort consisted of 539 participants without overt cardiac disease who underwent extensive cardiovascular examination. Aortic root diameter was measured by two-dimensional echocardiography and ePWV was calculated from a regression equation using age and mean blood pressure. LV global longitudinal strain (LVGLS) was obtained by speckle-tracking echocardiography. RESULTS: Aortic root diameter and ePWV were correlated with LV mass index and LVGLS, while only ePWV was related to E / e' ratio. In multivariable analysis, aortic root diameter and ePWV were significantly related to LV mass index and LVGLS (all P  < 0.05), and the association of aortic root size and ePWV with LVGLS was independent of LV mass index and E / e' ratio. Individuals with both aortic root enlargement and increased ePWV had significantly larger LV mass index and reduced LVGLS compared with those either or those with normal aortic size and ePWV (both P  < 0.05). CONCLUSION: Aortic root size and ePWV were independently associated with unfavorable LV remodeling in individuals free of cardiac disease, which might provide useful information into the pathogenesis-linking arterial remodeling and heart failure.

Incidence of atrial functional tricuspid regurgitation and its correlation with tricuspid valvular deformation in patients with persistent atrial fibrillation.

Background: With the growing prevalence of atrial fibrillation (AF), concomitant atrial functional tricuspid regurgitation (FTR) is increasing. In this study, we aimed to elucidate the incidence of significant atrial FTR and its association with tricuspid valvular (TV) deformation in patients with persistent AF. Methods: We retrospectively enrolled 344 patients (73.0 ± 9.3 years, 95 female) with persistent AF who underwent 2-dimensional echocardiography. We excluded patients with left-sided heart disease, pulmonary hypertension treated with pulmonary vasodilators, and congenital heart disease. We defined significant TR as having TR ≥ moderate; and tricuspid annulus (TA) diameter, tethering height, and area were measured in all patients. Results: Among the study population, 80 (23.3%) patients had significant TR. TA diameter, tethering height, and area were significantly greater in the significant TR group (all p < 0.001). In multivariable analysis, TA diameter was independently associated with significant TR (odds ratio 1.1 per mm, p = 0.03), whereas TV tethering height was not. Receiver operating characteristic curve for significant TR exhibited the best predictive value of TA diameter indexed for body surface area [23 mm/m2; area under the curve (AUC) = 0.87] compared with absolute TA diameter (39 mm; AUC = 0.74) and TA diameter indexed for height (0.22 mm/cm; AUC = 0.80). Conclusion: Approximately 25% of patients with persistent AF had significant TR. The BSA-corrected TA diameter was strongly associated with significant TR, which might be helpful for predicting the development of significant TR and considering its therapeutic strategy in patients with persistent AF.

Impact of insulin resistance on subclinical left ventricular dysfunction in normal weight and overweight/obese japanese subjects in a general community.

BACKGROUND: Insulin resistance carries increased risk of heart failure, although the pathophysiological mechanisms remain unclear. LV global longitudinal strain (LVGLS) assessed by speckle-tracking echocardiography has emerged as an important tool to detect early LV systolic abnormalities. This study aimed to investigate the association between insulin resistance and subclinical left ventricular (LV) dysfunction in a sample of the general population without overt cardiac disease. METHODS: We investigated 539 participants who voluntarily underwent extensive cardiovascular health check including laboratory test and speckle-tracking echocardiography. Glycemic profiles were categorized into 3 groups according to homeostatic model assessment of insulin resistance (HOMA-IR): absence of insulin resistance (HOMA-IR < 1.5), presence of insulin resistance (HOMA-IR ≥ 1.5) and diabetes mellitus (DM). Multivariable logistic regression models were conducted to evaluate the association between abnormal glucose metabolism and impaired LVGLS (> - 16.65%). RESULTS: Forty-five (8.3%) participants had DM and 66 (12.2%) had abnormal HOMA-IR. LV mass index and E/e' ratio did not differ between participants with and without abnormal HOMA-IR, whereas abnormal HOMA-IR group had significantly decreased LVGLS (- 17.6 ± 2.6% vs. - 19.7 ± 3.1%, p < 0.05). The prevalence of impaired LVGLS was higher in abnormal HOMA-IR group compared with normal HOMA-IR group (42.4% vs. 14.0%) and similar to that of DM (48.9%). In multivariable analyses, glycemic abnormalities were significantly associated with impaired LVGLS, independent of traditional cardiovascular risk factors and pertinent laboratory and echocardiographic parameters [adjusted odds ratio (OR) 2.38, p = 0.007 for abnormal HOMA-IR; adjusted OR 3.02, p = 0.003 for DM]. The independent association persisted even after adjustment for waist circumference as a marker of abdominal adiposity. Sub-group analyses stratified by body mass index showed significant association between abnormal HOMA-IR and impaired LVGLS in normal weight individuals (adjusted OR 4.59, p = 0.001), but not in overweight/obese individuals (adjusted OR 1.62, p = 0.300). CONCLUSIONS: In the general population without overt cardiac disease, insulin resistance carries independent risk for subclinical LV dysfunction, especially in normal weight individuals.

Chronic kidney disease and subclinical abnormalities of left heart mechanics in the community.

Aims: Cardiovascular disease is the leading cause of death in chronic kidney disease (CKD) patients, although the pathophysiological mechanisms are not fully studied. This study aimed to determine whether CKD could adversely affect subclinical left heart function in a sample of the general population without cardiac disease. Methods and results: We examined 1158 participants who voluntarily underwent extensive cardiovascular examination including laboratory test and two-dimensional speckle-tracking echocardiography to assess left ventricular global longitudinal strain (LVGLS) and left atrial (LA) reservoir, conduit, and pump strain. According to the estimated glomerular filtration rate (eGFR), participants were classified into four groups; Stage 1 (n = 112; eGFR ≥90 mL/min/1.73 m2), Stage 2 (n = 818; 60-89 mL/min/1.73 m2), Stage 3a (n = 191; 45-59 mL/min/1.73 m2), and Stage 3b-5 (n = 37; eGFR <45 mL/min/1.73 m2). Progressive declines of LVGLS, LA reservoir, and conduit strain were observed according to the severity of CKD (P < 0.001), while LA pump strain did not differ between the groups. In multivariable analyses, eGFR was associated with LVGLS (standardized ß = -0.068, P = 0.019) as well as LA reservoir (standardized ß = 0.117, P < 0.001) and conduit strain (standardized ß = 0.130, P < 0.001), independent of traditional cardiovascular risk factors, pertinent biomarkers, and LV geometry and diastolic function. The independent association between eGFR and LA strain persisted even after adjustment for LVGLS. Conclusion: Worsening renal function was independently associated with impaired LV/LA strain in an unselected community-based cohort. The assessment of LV and LA strain may allow better risk stratification in CKD patients.

Subclinical Hypothyroidism as an Independent Determinant of Left Atrial Dysfunction in the General Population.

PURPOSE: Although subclinical hypothyroidism (SCH) is a common clinical entity and carries independent risk for incident heart failure (HF), its possible association with subclinical cardiac dysfunction is unclear. Left ventricular global longitudinal strain (LVGLS) and left atrial (LA) phasic strain can unmask subclinical left heart abnormalities and are excellent predictors for HF. This study aimed to investigate the association between the presence of SCH and subclinical left heart dysfunction in a sample of the general population without overt cardiac disease. METHODS: We examined 1078 participants who voluntarily underwent extensive cardiovascular health check-ups, including laboratory tests and 2-dimensional speckle-tracking echocardiography to assess LVGLS and LA reservoir, conduit, and pump strain. SCH was defined as an elevated serum thyroid-stimulating hormone level with normal concentration of free thyroxine. RESULTS: Mean age was 62 ±â€…12 years, and 56% were men. Seventy-eight (7.2%) participants exhibited SCH. Individuals with SCH had significantly reduced LA reservoir (37.1 ±â€…6.6% vs 39.1 ±â€…6.6%; P = 0.011) and conduit strain (17.3 ±â€…6.3% vs 19.3 ±â€…6.6%; P = 0.012) compared with those with euthyroidism, whereas there was no significant difference in left ventricular ejection fraction, LA volume index, LVGLS, and LA pump strain between the 2 groups. In multivariable analyses, SCH remained associated with impaired LA reservoir strain, independent of age, traditional cardiovascular risk factors, and pertinent laboratory and echocardiographic parameters. including LVGLS (standardized ß -0.054; P = 0.032). CONCLUSIONS: In an unselected community-based cohort, individuals with SCH had significantly impaired LA phasic function. This association may be involved in the higher incidence of HF in subjects with SCH.

Correction to: Performance of 99mTc-aprotinin scintigraphy for diagnosing light chain (AL) cardiac amyloidosis confirmed by endomyocardial biopsy.

This prospective study was conducted according to the principles outlined within the Declaration of Helsinki, and approved by the Ethics Review Board of National Center for Global Health and Medicine (NCGM-G-00839-01, NCGM-G-00839-02).

Use of a Non-invasive Cardiac Output Measurement in a Patient with Low-output Dilated Cardiomyopathy.

A 49-year-old man was diagnosed with acute cardiac insufficiency based on evidence of congestive heart failure. The non-invasive measurement of the cardiac output using an AESCULON® mini showed low cardiac output (CO, 3.9 L/min). We administered an intravenous diuretic for cardiac edema and dobutamine drip for low cardiac output. Soon after starting dobutamine at 3.2 γ (microg/kg/min), the CO improved to 6.8 L/min. Combination therapy of diuretic and dobutamine resolved the heart failure. CO measurement by an AESCULON® mini was safe, cost-effective, and convenient. Data output correlates with the CO by Swan-Ganz catheterization. The non-invasive measurement of the CO permitted a smooth recovery without recurrence in this patient.

Performance of 99mTc-aprotinin scintigraphy for diagnosing light chain (AL) cardiac amyloidosis confirmed by endomyocardial biopsy.

BACKGROUND: Light chain (AL) cardiac amyloidosis is associated with a poor prognosis. Diagnosing at an early stage is critical for treatment and the management of cardiac complication. PURPOSE: We aimed to evaluate the diagnostic performance of 99mTc-aprotinin images in patients with AL cardiac amyloidosis. METHODS AND RESULTS: 99mTc-aprotinin scintigraphy and endomyocardial biopsy were performed in 10 patients with suspected amyloidosis. Endomyocardial biopsy showed amyloid deposits in 5 of 10 patients. 99mTc-aprotinin (planer image) was positive in 4 of 5 patients who had amyloid deposits in endomyocardial biopsy. On the other hand, all 5 patients without amyloid deposits were negative in planer image. 99mTc-aprotinin (SPECT/CT image) was positive in all 5 patients who had amyloid deposits. CONCLUSIONS: 99mTc-aprotinin scintigraphy is valuable for the non-invasive diagnosis of AL cardiac amyloidosis.

Significance of 11C-PIB PET/CT in cardiac amyloidosis compared with 99mTc-aprotinin scintigraphy: A pilot study.

BACKGROUND: This study was to investigate the significance of 11C-Pittsburgh B (PIB) PET/CT in patients with suspected cardiac amyloidosis compared with 99mTc-aprotinin scintigraphy. METHODS: Thirteen consecutive patients with suspected cardiac amyloidosis were considered for enrolment in this prospective pilot study. Participants were scheduled to undergo a series of 11C-PIB PET/CT and 99mTc-aprotinin within a 2-month period. Finally, we evaluated nine cases who underwent both imaging modalities, and compared imaging results with clinical and pathological results and prognosis. RESULTS: Six of the 9 patients who underwent both imaging modalities were diagnosed with amyloidosis, of whom 3 patients were diagnosed with cardiac amyloidosis from endomyocardial biopsy. These 3 patients with positive 11C-PIB uptake at the left ventricle wall showed worsening of cardiac function progressing in the short term or death caused by acute exacerbation of chronic heart failure. Six of 8 patients with positive uptake on 99mTc-aprotinin presented with amyloid deposition in the left ventricle wall, but symptoms remained stable if results of 11C-PIB were not positive. CONCLUSION: In a small sample of subjects, the present study showed that 11C-PIB accumulation in myocardium indicated cardiac amyloidosis with poor prognosis. Uptake of 11C-PIB may be related to progressive amyloid deposition to the heart and can predict patient prognosis.