Incremental value of diastolic stress test in identifying subclinical heart failure in patients with diabetes mellitus

Cardiac diastolic maladaptation is associated with the severity of exercise intolerance in sickle cell anemia patients

This pilot study focusing on Sickle Cell Anemia (SCA) patients offers a comprehensive and integrative evaluation of respiratory, cardiovascular, hemodynamic, and metabolic variables during exercise. Knowing that diastolic dysfunction is frequent in this population, we hypothesize that a lack of cardiac adaptation through exercise might lead to premature increase in blood lactate concentrations in SCA patients, a potential trigger for acute disease complication. SCA patients were prospectively included in PHYSIO-EXDRE study and underwent a comprehensive stress test with a standardized incremental exercise protocol up to 4 mmol L-1 blood lactate concentration (BL4). Gas exchange, capillary lactate concentration and echocardiography were performed at baseline, during stress test (at ∼ 2 mmol L-1) and BL4. The population was divided into two groups and compared according to the median value of percentage of theoretical peak oxygen uptake (%V ˙ O 2 p e a k t h ) at BL4. Twenty-nine patients were included (42 ± 12 years old, 48% of women). Most patients reached BL4 at low-intensity exercise [median value of predicted power output (W) was 37%], which corresponds to daily life activities. The median value of %V ˙ O 2 p e a k t h at BL4 was 39%. Interestingly, diastolic maladaptation using echocardiography during stress test along with hemoglobin concentration were independently associated to early occurrence of BL4. As BL4 occurs for low-intensity exercises, SCA patients may be subject to acidosis-related complications even during their daily life activities. Beyond assessing physical capacities, our study underlines that diastolic maladaptation during exercise is associated with an early increase in blood lactate concentration.

Abnormal left ventricular systolic reserve function detected by treadmill exercise stress echocardiography in asymptomatic type 2 diabetes

Aims

Subclinical left ventricular (LV) dysfunction may occur in T2DM patients at the early asymptomatic stage, and LV reserve function is a sensitive index to detect subtle LV dysfunction. The purpose of our study is (1) to assess the LV reserve function using treadmill exercise stress echocardiography (ESE) in asymptomatic type 2 diabetes mellitus (T2DM) patients; (2) to explore the link of serum biological parameters and LV reserve function.

Methods

This study included 84 patients with asymptomatic T2DM from September 2021 to July 2022 and 41 sex- and age-matched healthy controls during the corresponding period. All subjects completed treadmill ESE, LV systolic function-related parameters such as global longitudinal strain (GLS) and systolic strain rate (SRs), as well as diastolic function-related parameters such as E wave (E), early diastolic velocity (e'), E/e' ratio, early diastolic SR (SRe), and late diastolic SR (SRa) were compared at rest and immediately after exercise. The difference between LV functional parameters after treadmill exercise and its corresponding resting value was used to compute LV reserve function. In addition, the associations of LV reserve function and serum biological parameters were analyzed.

Results

Patients with T2DM did not significantly vary from the controls in terms of alterations in LV diastolic reserve measures, the changes of LVGLS and SRs (ΔGLS: 2.19 ± 2.72% vs. 4.13 ± 2.79%, P < 0.001 and ΔSRs:0.78 ± 0.33 s-1 vs. 1.02 ± 0.28 s-1, P < 0.001) in the T2DM group were both lower than those in the control group. Glycated hemoglobin (HbA1c), N-terminal pro-brain natriuretic peptide (NTproBNP), waist circumference, and high-sensitive C-reactive protein (hsCRP) were identified as independent predictors of LV systolic reserve by stepwise multiple linear regression analysis.

Conclusion

LV systolic reserve function, as measured by pre- and post-exercise differences in GLS and SRs were significantly impaired in patients with asymptomatic T2DM, whereas diastolic reserve remained normal during exercise and was comparable to that of the control group. This was different from previous findings. High levels of HbA1c, NTproBNP, hsCRP, and increasing waist circumference were independent predictors of LV systolic reserve.

Coronary artery disease is associated with impaired atrial function regardless of left ventricular filling pressure

BACKGROUND

Left atrial (LA) strain is impaired in left ventricular (LV) diastolic dysfunction, associated with increased LV end diastolic pressure (LVEDP). In patients with preserved LV ejection fraction (LVEF), coronary artery disease (CAD) is known to impair LV diastolic function. The relationship of LVEDP with CAD and impact on LA strain is not well studied.

METHODS AND RESULTS

Patients with LVEF >50% (n = 37, age 61 ± 7 years) underwent coronary angiography, high-fidelity LV pressure measurements and cardiac magnetic resonance imaging. LA volumes, LA emptying fraction (LAEF), LA reservoir strain (LARS) and LA long-axis shortening (LALAS) were measured. By coronary angiography, patients were assigned into 3 groups: severe-CAD (n = 19, with obstruction of major coronary arteries >70% and/or history of coronary revascularization), mild-to-moderate-CAD (n = 10, obstruction of major coronary arteries 30-60%), and no-CAD (n = 8, obstruction of major coronary arteries and branches <30%). Overall, LVEF was 65 ± 8% and LVEDP was 14.4 ± 5.6 mmHg. Clinical characteristics, LVEDP and LV function measurements were similar in 3 groups. Severe-CAD group had lower LAEF, LALAS and LARS than those in no-CAD group (P < 0.05 all). In regression analysis, LARS and LALAS were associated with CAD severity and treatment with Nitrates, whereas LAEF and LAEFactive were associated with CAD severity, treatment with Nitrates and LA minimum volume (P < 0.05 all). LAEFpassive was associated with LVED volume (P < 0.05).

CONCLUSIONS

LA functional impairment may be affected by coexistent CAD severity, medications, in particular, Nitrates, and loading conditions, which should be considered when assessing LA function and LA-LV interaction. Our findings inspire exploration in a larger cohort.

Pulmonary hypertension during exercise underlies unexplained exertional dyspnoea in patients with Type 2 diabetes

AIMS

To compare the cardiac function and pulmonary vascular function during exercise between dyspnoeic and non-dyspnoeic patients with Type 2 diabetes mellitus (T2DM).

METHODS AND RESULTS

Forty-seven T2DM patients with unexplained dyspnoea and 50 asymptomatic T2DM patients underwent exercise echocardiography combined with ergospirometry. Left ventricular (LV) function [stroke volume, cardiac output (CO), LV ejection fraction, systolic annular velocity (s')], estimated LV filling pressures (E/e'), mean pulmonary arterial pressures (mPAPs) and mPAP/COslope were assessed at rest, low- and high-intensity exercise with colloid contrast. Groups had similar patient characteristics, glycemic control, stroke volume, CO, LV ejection fraction, and E/e' (P > 0.05). The dyspnoeic group had significantly lower systolic LV reserve at peak exercise (s') (P = 0.021) with a significant interaction effect (P < 0.001). The dyspnoeic group also had significantly higher mPAP and mPAP/CO at rest and exercise (P < 0.001) with significant interaction for mPAP (P < 0.009) and insignificant for mPAP/CO (P = 0.385). There was no significant difference in mPAP/COslope between groups (P = 0.706). However, about 61% of dyspnoeic vs. 30% of non-dyspnoeic group had mPAP/COslope > 3 (P = 0.009). The mPAP/COslope negatively predicted V̇O2peak in dyspneic group (β = -1.86, 95% CI: -2.75, -0.98; multivariate model R2:0.54).

CONCLUSION

Pulmonary hypertension and less LV systolic reserve detected by exercise echocardiography with colloid contrast underlie unexplained exertional dyspnoea and reduced exercise capacity in T2DM.

Impact of continuous vs. interval training on oxygen extraction and cardiac function during exercise in type 2 diabetes mellitus

PURPOSE

Exercise training improves exercise capacity in type 2 diabetes mellitus (T2DM). It remains to be elucidated whether such improvements result from cardiac or peripheral muscular adaptations, and whether these are intensity dependent.

METHODS

27 patients with T2DM [without known cardiovascular disease (CVD)] were randomized to high-intensity interval training (HIIT, n = 15) or moderate-intensity endurance training (MIT, n = 12) for 24 weeks (3 sessions/week). Exercise echocardiography was applied to investigate cardiac output (CO) and oxygen (O₂) extraction during exercise, while exercise capacity [([Formula: see text] (mL/kg/min)] was examined via cardiopulmonary exercise testing at baseline and after 12 and 24 weeks of exercise training, respectively. Changes in glycaemic control (HbA1c and glucose tolerance), lipid profile and body composition were also evaluated.

RESULTS

19 patients completed 24 weeks of HIIT (n = 10, 66 ± 11 years) or MIT (n = 9, 61 ± 5 years). HIIT and MIT similarly improved glucose tolerance (p_Time = 0.001, p_Interaction > 0.05), [Formula: see text] (mL/kg/min) (p_Time = 0.001, p_Interaction > 0.05), and exercise performance (W_peak) (p_Time < 0.001, p_Interaction > 0.05). O₂ extraction increased to a greater extent after 24 weeks of MIT (56.5%, p₁ = 0.009, p_Time = 0.001, p_Interaction = 0.007). CO and left ventricular longitudinal strain (LS) during exercise remained unchanged (p_Time > 0.05). A reduction in HbA1c was correlated with absolute changes in LS after 12 weeks of MIT (r = - 0.792, p = 0.019, LS at rest) or HIIT (r = - 0.782, p = 0.038, LS at peak exercise).

CONCLUSION

In patients with well-controlled T2DM, MIT and HIIT improved exercise capacity, mainly resulting from increments in O₂ extraction capacity, rather than changes in cardiac output. In particular, MIT seemed highly effective to generate these peripheral adaptations.

TRIAL REGISTRATION

NCT03299790, initially released 09/12/2017.

The year 2020 in the European Heart Journal-Cardiovascular Imaging: part II

The European Heart Journal-Cardiovascular Imaging was launched in 2012 and has during these years become one of the leading multimodality cardiovascular imaging journal. The journal is now established as one of the top cardiovascular journals and is the most important cardiovascular imaging journal in Europe. The most important studies published in our Journal from 2020 will be highlighted in two reports. Part II will focus on valvular heart disease, heart failure, cardiomyopathies, and congenital heart disease. While Part I of the review has focused on studies about myocardial function and risk prediction, myocardial ischaemia, and emerging techniques in cardiovascular imaging.

Peripheral Oxygen Extraction and Exercise Limitation in Asymptomatic Patients with Diabetes Mellitus

Patients with diabetes mellitus (DM) frequently present reduced exercise capacity. We aimed to explore the extent to which peripheral extraction relates to exercise capacity in asymptomatic patients with DM. We prospectively enrolled 98 asymptomatic patients with type-2 DM (mean age of 59 ± 11 years and 56% male sex), and compared with 31 age, sex and body mass index-matched normoglycemic controls. Cardiopulmonary exercise testing with resting followed by stress echocardiography was performed. Exercise response was assessed using peak oxygen uptake (peak VO₂) and ventilatory efficiency was measured using the slope of the relationship between minute ventilation and carbon dioxide production (VE/VCO₂). Peripheral extraction was calculated as the ratio of VO₂ to cardiac output. Cardiac function was evaluated using left ventricular longitudinal strain, E/e', and relative wall thickness. Among patients with DM, 26 patients (27%) presented reduced percent-predicted-peak VO₂(<80%) and 18 (18%) presented abnormal VE/VCO₂slope (>34). There was no significant difference in peak cardiac output; however, peripheral extraction was lower in patients with DM compared to controls. Higher peak E/e' (beta = -0.24, p = 0.004) was associated with lower peak VO₂ along with age, sex and body mass index (R² = 0.53). A cluster analysis found left ventricular longitudinal strain, E/e', relative wall thickness and peak VO₂ in different clusters. In conclusion, impaired peripheral extraction may contribute to reduced peak VO₂in asymptomatic patients with DM. Furthermore, a cluster analysis suggests that cardiopulmonary exercise testing and echocardiography may be complementary for defining subclinical heart failure in patients with DM.

Asymptomatic type 2 diabetes mellitus display a reduced myocardial deformation but adequate response during exercise

BACKGROUND AND PURPOSE

The development of myocardial fibrosis is a major complication of Type 2 diabetes mellitus (T2DM), impairing myocardial deformation and, therefore, cardiac performance. It remains to be established whether abnormalities in longitudinal strain (LS) exaggerate or only occur in well-controlled T2DM, when exposed to exercise and, therefore, cardiac stress. We therefore studied left ventricular LS at rest and during exercise in T2DM patients vs. healthy controls.

METHODS AND RESULTS

Exercise echocardiography was applied with combined breath-by-breath gas exchange analyses in asymptomatic, well-controlled (HbA1c: 6.9 ± 0.7%) T2DM patients (n = 36) and healthy controls (HC, n = 23). Left ventricular LS was assessed at rest and at peak exercise. Peak oxygen uptake (V̇O_2peak) and workload (W_peak) were similar between groups (p > 0.05). Diastolic (E, e'_s, E/e') and systolic function (left ventricular ejection fraction) were similar at rest and during exercise between groups (p > 0.05). LS (absolute values) was significantly lower at rest and during exercise in T2DM vs. HC (17.0 ± 2.9% vs. 19.8 ± 2% and 20.8 ± 4.0% vs. 23.3 ± 3.3%, respectively, p < 0.05). The response in myocardial deformation (the change in LS from rest up to peak exercise) was similar between groups (+ 3.8 ± 0.6% vs. + 3.6 ± 0.6%, in T2DM vs. HC, respectively, p > 0.05). Multiple regression revealed that HDL-cholesterol, fasted insulin levels and exercise tolerance accounted for 30.5% of the variance in response of myocardial deformation in the T2DM group (p = 0.002).

CONCLUSION

Myocardial deformation is reduced in well-controlled T2DM and despite adequate responses, such differences persist during exercise.

TRIAL REGISTRATION

NCT03299790, initially released 09/12/2017.

Cardiovascular Determinants of Aerobic Exercise Capacity in Adults With Type 2 Diabetes

OBJECTIVE

To assess the relationship between subclinical cardiac dysfunction and aerobic exercise capacity (peak VO₂) in adults with type 2 diabetes (T2D), a group at high risk of developing heart failure.

RESEARCH DESIGN AND METHODS

Cross-sectional study. We prospectively enrolled a multiethnic cohort of asymptomatic adults with T2D and no history, signs, or symptoms of cardiovascular disease. Age-, sex-, and ethnicity-matched control subjects were recruited for comparison. Participants underwent bioanthropometric profiling, cardiopulmonary exercise testing, and cardiovascular magnetic resonance with adenosine stress perfusion imaging. Multivariable linear regression analysis was undertaken to identify independent associations between measures of cardiovascular structure and function and peak VO₂.

RESULTS

A total of 247 adults with T2D (aged 51.8 ± 11.9 years, 55% males, 37% black or south Asian ethnicity, HbA_1c 7.4 ± 1.1% [57 ± 12 mmol/mol], and duration of diabetes 61 [32-120] months) and 78 control subjects were included. Subjects with T2D had increased concentric left ventricular remodeling, reduced myocardial perfusion reserve (MPR), and markedly lower aerobic exercise capacity (peak VO₂ 18.0 ± 6.6 vs. 27.8 ± 9.0 mL/kg/min; P < 0.001) compared with control subjects. In a multivariable linear regression model containing age, sex, ethnicity, smoking status, and systolic blood pressure, only MPR (β = 0.822; P = 0.006) and left ventricular diastolic filling pressure (E/e') (β = -0.388; P = 0.001) were independently associated with peak VO₂ in subjects with T2D.

CONCLUSIONS

In a multiethnic cohort of asymptomatic people with T2D, MPR and diastolic function are key determinants of aerobic exercise capacity, independent of age, sex, ethnicity, smoking status, or blood pressure.

Cardiorespiratory fitness in patients with type 2 diabetes: A missing piece of the puzzle

Functional capacity represents an important predictor for cardiovascular and all-cause mortality in patients with diabetes mellitus (DM). Impaired cardiopulmonary fitness is frequently seen in DM patients, and it might partly explain morbidity and mortality in these patients. There are several potential reasons that could explain impaired functional capacity in DM patients: hyperglycemia, insulin resistance, endothelial dysfunction, inflammation, microvascular impairment, myocardial dysfunction, and skeletal muscle changes. These changes are partly reversible, and improvement of any of these components might increase functional capacity in DM patients and improve their outcome. Physical activity is related with decreased cardiovascular disease and all-cause mortality in patients with type 2 DM. Diabetic cardiomyopathy is the most important clinical entity in DM patients that involves left ventricular diastolic dysfunction and cardiac autonomic neuropathy, which potentially induce heart failure with preserved ejection fraction. Development of diabetic cardiomyopathy may slow oxygen uptake kinetics and affect the cardiorespiratory fitness in DM patients, but it can also induce development of heart failure. Improvement of functional capacity in DM patients represents an important therapeutic task, and it can be achieved mainly with exercise training and significantly less with pharmacological treatment. Exercise training reduces body weight and improves glycemic control, as well as left ventricular structure and function. The aim of this review was to summarize current knowledge about importance of functional capacity in DM patients, as well as possible mechanisms that could explain the relationship between DM and oxygen kinetics.