Cardiac dysfunction rather than aortic valve stenosis severity drives exercise intolerance and adverse haemodynamics

AIMS

To study the impact of heart failure with preserved ejection fraction (HFpEF) vs. aortic stenosis (AS) lesion severity on left ventricular (LV) hypertrophy, diastolic dysfunction, left atrial (LA) dysfunction, haemodynamics, and exercise capacity.

METHODS AND RESULTS

Patients (n = 206) with at least moderate AS (aortic valve area ≤0.85 cm/m2) and discordant symptoms underwent cardiopulmonary exercise testing with simultaneous echocardiography. The population was stratified according to the probability of underlying HFpEF by the heavy, hypertension, atrial fibrillation, pulmonary hypertension, elder, filling pressure (H2FPEF) score [0-5 (AS/HFpEF-) vs. 6-9 points (AS/HFpEF+)] and AS severity (Moderate vs. Severe). Mean age was 73 ± 10 years with 40% women. Twenty-eight patients had Severe AS/HFpEF+ (14%), 111 Severe AS/HFpEF- (54%), 13 Moderate AS/HFpEF+ (6%), and 54 Moderate AS/HFpEF- (26%). AS/HFpEF+ vs. AS/HFpEF- patients, irrespective of AS severity, had a lower LV global longitudinal strain, impaired diastolic function, reduced LV compliance, and more pronounced LA dysfunction. The pulmonary arterial pressure-cardiac output slope was significantly higher in AS/HFpEF+ vs. AS/HFpEF- (5.4 ± 3.1 vs. 3.9 ± 2.2 mmHg/L/min, respectively; P = 0.003), mainly driven by impaired cardiac output and chronotropic reserve, with signs of right ventricular pulmonary arterial uncoupling. AS/HFpEF+ vs. AS/HFpEF- was associated with a lower peak aerobic capacity (11.5 ± 3.7 vs. 15.9 ± 5.9 mL/min/kg, respectively; P < 0.0001) but did not differ between Moderate and Severe AS (14.7 ± 5.5 vs. 15.2 ± 5.9 mL/min/kg, respectively; P = 0.6).

CONCLUSION

A high H2FPEF score is associated with a reduced exercise capacity and adverse haemodynamics in patients with moderate to severe AS. Both exercise performance and haemodynamics correspond better with intrinsic cardiac dysfunction than AS severity.

Heart failure with preserved ejection fraction: relevance of a dedicated dyspnoea clinic

BACKGROUND AND AIMS

Heart failure with preserved ejection fraction (HFpEF) is a syndrome with a heterogeneous presentation. This study provides an in-;depth description of haemodynamic and metabolic alterations revealed by systematic assessment through cardiopulmonary exercise testing combined with exercise echocardiography (CPETecho) within a dedicated dyspnoea clinic.

METHODS AND RESULTS

Consecutive patients (n = 297), referred to a dedicated dyspnoea clinic using a standardized workup including CPETecho, with HFpEF diagnosed through a H2FPEF score ≥6 or HFA-PEFF score ≥5, were evaluated. A median of four haemodynamic/metabolic alterations was uncovered per patient: impaired stroke volume reserve (73%), impaired chronotropic reserve (72%), exercise pulmonary hypertension (65%), and impaired diastolic reserve (64%) were the most frequent cardiac alterations. Impaired peripheral oxygen extraction and a ventilatory limitation were present in 40% and 39%, respectively. In 267 patients (90%), 575 further diagnostic examinations were recommended (median of two tests per patient). Cardiac magnetic resonance imaging, coronary or amyloidosis workup, ventilation-perfusion scanning, and pulmonology referral were each recommended in approximately one out of three patients. In 293 patients (99%), 929 cardiovascular drug optimizations were performed (median of 3 modifications per patient). In 110 patients (37%), 132 cardiovascular interventions were performed, with ablation as the most frequent procedure.

CONCLUSION

Holistic workup of HFpEF patients within a multidisciplinary, dedicated dyspnoea clinic, including systematic implementation of CPETecho reveals various haemodynamic/metabolic alterations, leading to further diagnostic testing and potential treatment changes in the majority of cases.

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.

Dynamic Takotsubo Syndrome: When SCAD Hides in a Pot

Both Takotsubo cardiomyopathy and spontaneous coronary artery dissection (SCAD) of the distal portion of the left anterior descending artery affect the apical myocardium. It is important to distinguish between both diseases, because therapy and follow-up differ. Revascularization may be lifesaving in SCAD, whereas heart failure management is vital in Takotsubo cardiomyopathy. (Level of Difficulty: Intermediate.)

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.

Exercise capacity is related to attenuated responses in oxygen extraction and left ventricular longitudinal strain in asymptomatic type 2 diabetes patients

AIMS

Type 2 diabetes mellitus (T2DM) is associated with reduced exercise capacity and cardiovascular diseases, both increasing morbidity and risk for premature death. As exercise intolerance often relates to cardiac dysfunction, it remains to be elucidated to what extent such an interplay occurs in T2DM patients without overt cardiovascular diseases. Design: Cross-sectional study, NCT03299790.

METHODS AND RESULTS

Fifty-three T2DM patients underwent exercise echocardiography (semi-supine bicycle) with combined ergospirometry. Cardiac output (CO), left ventricular longitudinal strain (LS), oxygen uptake (O2), and oxygen (O2) extraction were assessed simultaneously at rest, low-intensity exercise, and high-intensity exercise. Glycaemic control and lipid profile were assessed in the fasted state. Participants were assigned according to their exercise capacity being adequate or impaired (EXadequate: O2peak <80% and EXimpaired: O2peak ≥80% of predicted O2peak) to compare O2 extraction, CO, and LS at all stages. Thirty-eight participants (EXimpaired: n = 20 and EXadequate: n = 18) were included in the analyses. Groups were similar regarding HbA1c, age, and sex (P > 0.05). At rest, CO was similar in the EXimpaired group vs. EXadequate group (5.1 ± 1 L/min vs. 4.6 ± 1.4 L/min, P > 0.05) and increased equally during exercise. EXimpaired patients displayed a 30.7% smaller increase in O2 extraction during exercise compared to the EXadequate group (P = 0.016) which resulted in a lower O2 extraction at high-intensity exercise (12.5 ± 2.8 mL/dL vs. 15.3 ± 3.9 mL/dL, P = 0.012). Left ventricular longitudinal strain was similar at rest but increased significantly less in the EXimpaired vs. EXadequate patients (1.9 ± 2.5% vs. 5.9 ± 4.1%, P = 0.004).

CONCLUSIONS

In asymptomatic T2DM patients, an impaired exercise capacity is associated with an impaired response in oxygen extraction and myocardial deformation (LS).

TRIAL REGISTRY

Effect of High-intensity Interval Training on Cardiac Function and Regulation of Glycemic Control in Diabetic Cardiomyopathy (https://clinicaltrials.gov/ct2/show/NCT03299790).