Factors influencing left atrial volume in a population with preserved ejection fraction: Left ventricular diastolic dysfunction or clinical factors?

Factors associated with changes in echocardiographic parameters following kidney transplantation

BACKGROUND

Chronic kidney disease leads to cardiac remodelling of multifactorial origin known as "uraemic cardiomyopathy", the reversibility of which after kidney transplantation (KT) remains controversial. Our objectives were to assess, in the modern era, changes in echocardiographic parameters following KT and identify predictive clinical and biological factors associated with echocardiographic changes.

METHODS

One hundred six patients (mean age 48 ± 16, 73% male) who underwent KT at the University Hospital of Nancy between 2007 and 2018 were retrospectively investigated. Pre- and post-KT echocardiography findings (8.6 months before and 22 months after KT on average, respectively) were centralised, blind-reviewed and compared.

RESULTS

A majority of patients (60%) had either a left ventricular (LV) ejection fraction < 50%, at least moderately abnormal LV mass index or left atrial (LA) dilatation at pretransplanted echocardiography. After KT, LV remodelling and diastolic doppler indices did not significantly change whereas LA volume index (LAVI) increased (35.9 mL/m2 post-KT vs. 30.9 mL/m2 pre-KT, p = 0.006). Advancing age, cardiac valvular disease, delayed graft function, lower post-KT haemoglobin, and more severe post-KT hypertension were associated with higher LAVI after KT. Higher post-KT serum creatinine, more severe post-KT hypertension and lower pre-KT blood calcium levels were associated with a deterioration in LAVI after KT.

DISCUSSION/CONCLUSION

Adverse remodelling of the left atrial volume occurred after KT, predominantly in patients with lower pre-KT blood calcium, poorer graft function and post-KT hypertension. These results suggest that a better management of modifiable factors such as pre-KT hyperparathyroidism or post-KT hypertension could limit post-KT cardiac remodelling.

Increased left atrial volume index is associated with more cardiovascular events in patients with acute coronary syndrome: HIJ-PROPER study findings

AIM

To investigate the association between the left atrial volume index (LAVI) and the incidence of cardiovascular events in patients with acute coronary syndrome (ACS) who did not have atrial fibrillation (AF).

METHODS

In this sub-analysis of the HIJ-PROPER study, 226 ACS patients who did not have a history of AF were enrolled. Participants were divided into two groups according to the LAVI cut-off level calculated by receiver operating characteristic (ROC) curve analysis to predict the primary endpoint, and cardiovascular events were compared between groups. The primary endpoint was the first occurrence of all-cause death, non-fatal myocardial infarction, non-fatal stroke, and hospitalization for heart failure.

RESULTS

ROC curve analysis for the occurrence of composite of cardiovascular events indicated a LAVI cut-off point of 34 mL/m² . Based on this, 131 patients (58.0%) were in the LAVI < 34 mL/m² group and 95 (42.0%) were in the LAVI ≥ 34 mL/m² group. Over a median follow-up period of 4.0 years [interquartile range: 3.2, 5.1], cardiovascular events were noted in 7 and 15 patients in the LAVI < 34 mL/m² and LAVI ≥ 34 mL/m² groups, corresponding to an incidence rate of 5.3% and 15.8%, respectively. Patients with a LAVI value ≥ 34 mL/m² had a significantly higher risk of cardiovascular events than those with a LAVI value < 34 mL/m² (hazard ratio: 2.93; 95% confidence interval: 1.19-7.22; P = .014). The tendency was similar after adjusting for several confounders (P = .025).

CONCLUSION

In ACS patients without AF, elevated LAVI was associated with increased cardiovascular events.

CLINICAL TRIAL REGISTRATION

International standard randomized controlled trial (URL: https://www.umin.ac.jp; UMIN000002742).

Evaluation of left ventricular function in patients with acute ischaemic stroke using cine cardiovascular magnetic resonance imaging

AIMS

Heart failure (HF) is frequent in patients with acute ischaemic stroke (AIS) and associated with higher morbidity and mortality. Assessment of cardiac function in AIS patients using cardiovascular MRI (CMR) may help to detect HF. We report the rate of systolic and diastolic dysfunction in a cohort of patients with AIS using CMR and compare cine real-time (CRT) sequences with the reference of segmented cine steady-state free precession sequences.

METHODS AND RESULTS

Patients with AIS without known atrial fibrillation were prospectively enrolled in the HEart and BRain Interfaces in Acute Ischemic Stroke (HEBRAS) study (NCT02142413) and underwent CMR at 3 Tesla within 7 days after AIS. Validity of CRT sequences was determined in 50 patients. A total of 229 patients were included in the analysis (mean age 66 years; 35% women; HF 2%). Evaluation of cardiac function was successful in 172 (75%) patients. Median time from stroke onset to CMR was 82 h (interquartile range 56-111) and 54 h (interquartile range 31-78) from cerebral MRI to CMR. Systolic dysfunction was observed in 43 (25%) and diastolic dysfunction in 102 (59%) patients. Diagnostic yield was similar using CRT or segmented cine imaging (no significant difference in left ventricular ejection fraction, myocardial mass, time to peak filling rate, and peak filling rate ratio E/A). Intraobserver and interobserver agreement was high (κ = 0.78-1.0 for all modalities).

CONCLUSIONS

Cardiovascular MRI at 3 Tesla is an appropriate method for the evaluation of cardiac function in a selected cohort of patients with AIS. Systolic and diastolic dysfunction is frequent in these patients. CRT imaging allows reliable assessment of systolic and diastolic function.

Evaluation of the size of cardiac structures in patients with high body mass index

AIMS

Isometric indexation of cardiac structures fails in patients with overweight. The aim of the study was to evaluate the LA indexed volume (LAVOL), left ventricular end-diastolic diameter (LVEDD), left ventricular mass index (LVMI), and the aortic sinus diameter (AOSD) in healthy subjects with normal and high BMI and find the allometric correction exponent.

METHODS

Four hundred and thirty patients without cardiac pathology were analyzed. Patients were divided into groups: Group I BMI < 24.9 187 patients, Group II BMI 25-29.9 154 patients, Group III BMI 30-34.9 63 patients, and Group IV 35-39.9 26 patients. A Doppler echocardiogram was performed. The parameters indexed were compared between groups. When allometric growth was verified, the allometric coefficient was calculated.

RESULTS

Male sex 242 p (56%), mean age: 44.87 ± 13.10 years, better correlation: LAVOL, LV mass, and AOSD with body surface area (BSA) (LAVOL R: .74, R² .55, LV mass R: .73, R² : 0.53, AOSD R: .57, R² : .35), LVEDD with high (R: .63, R² : .39) were observed. A significant increase was observed in LAVOL and LVMI in the groups with increased BMI. We observed a decrease in the indexed AOSD and a marginal difference between groups in LVEDD. The allometric correction exponent calculated was as follows: LAVOL: 0.96 and for LVMI: 0.97.

CONCLUSIONS

Allometric correction is superior to isometric indexation to assess LAVOL and LVMI in obese and overweight patients. Allometric correction would allow differentiating deviations from VOLAI and IMVI attributable to obesity from those attributable to an associated pathology.

Mechanisms of Left Atrial Enlargement in Obesity

Left atrial (LA) enlargement is common in obesity. We sought to determine the influence of ventricular (LV) remodeling on LA size in obesity. We studied 50 otherwise healthy obese subjects (body mass index 37.2 ± 4.6 kg/m², 50 ± 6 years) and 58 age and gender-matched nonobese controls (body mass index 26.2 ± 2.9 kg/m², 52 ± 5 years). Diastolic function, relative wall thickness (RWT), and LV mass were assessed using echocardiography. LA and LV volume was measured by 3D-echocardiography. Primary outcome was the ratio of LA volume indexed to LV volume in obese and control subjects. Obese subjects had substantially larger LA volumes compared with control subjects (61.0 ± 16.9 vs 38.9 ± 9.2 ml, p < 0.0001). When scaled to body size or lean mass, differences in LA size persisted. However, when indexed to LV end-diastolic volume, LA volumes between control and obese subjects were comparable (obese vs controls: 0.44 ± 0.15 vs 0.42 ± 0.10, p = 0.46). A small subset of obese subjects (26%) had LA volume markedly out of proportion to LV volume (LA/LV volume ratio ≥0.5) and displayed concentric LV remodeling with larger RWT and LV mass compared with obese subjects with LA/LV <0.5 (RWT: 0.46 ± 0.09 vs 0.36 ± 0.06, p < 0.0001; LV mass: 79 ± 18 vs 62 ± 13 g/m² p < 0.01). In conclusion, LA enlargement in patients with obesity generally occurs commensurate with LV enlargement and parallels eccentric LV remodeling. LA enlargement out of proportion to LV size is associated with increased RWT and mass. This unique signature may identify obese subjects with pathologic LA remodeling.

Blunting of estrogen modulation of cardiac cellular chymase/RAS activity and function in SHR

The relatively low efficacy of ACE-inhibitors in the treatment of heart failure in women after estrogen loss may be due to their inability to reach the intracellular sites at which angiotensin (Ang) II is generated and/or the existence of cell-specific mechanisms in which ACE is not the essential processing pathway for Ang II formation. We compared the metabolic pathway for Ang II formation in freshly isolated myocytes (CMs) and non-myocytes (NCMs) in cardiac membranes extracted from hearts of gonadal-intact and ovariectomized (OVX) adult WKY and SHR rats. Plasma Ang II levels were higher in WKY vs. SHR (strain effect: WKY: 62 ± 6 pg/ml vs. SHR: 42 ± 9 pg/ml; p < 0.01), independent of OVX. The enzymatic activities of chymase, ACE, and ACE2 were higher in NCMs versus CMs, irrespective of whether assays were performed in cardiac membranes from WKY or SHR or in the presence or absence of OVX. E2 depletion increased chymase activity, but not ACE activity, in both CMs and NCMs. Moreover, cardiac myocyte chymase activity associated with diastolic function in WKYs and cardiac structure in SHRs while no relevant functional and structural relationships between the classic enzymatic pathway of Ang II formation by ACE or the counter-regulatory Ang-(1-7) forming path from Ang II via ACE2 were apparent. The significance of these novel findings is that targeted cell-specific chymase rather than ACE inhibition may have a greater benefit in the management of HF in women after menopause.