Variability of Myocardial Strain During Isometric Exercise in Subjects With and Without Heart Failure

Noninvasive evaluation of pulmonary artery stiffness in heart failure patients via cardiovascular magnetic resonance

Heart failure (HF) presents manifestations in both cardiac and vascular abnormalities. Pulmonary hypertension (PH) is prevalent in up 50% of HF patients. While pulmonary arterial hypertension (PAH) is closely associated with pulmonary artery (PA) stiffness, the association of HF caused, post-capillary PH and PA stiffness is unknown. We aimed to assess and compare PA stiffness and blood flow hemodynamics noninvasively across HF entities and control subjects without HF using CMR. We analyzed data of a prospectively conducted study with 74 adults, including 55 patients with HF across the spectrum (20 HF with preserved ejection fraction [HFpEF], 18 HF with mildly-reduced ejection fraction [HFmrEF] and 17 HF with reduced ejection fraction [HFrEF]) as well as 19 control subjects without HF. PA stiffness was defined as reduced vascular compliance, indicated primarily by the relative area change (RAC), altered flow hemodynamics were detected by increased flow velocities, mainly by pulse wave velocity (PWV). Correlations between the variables were explored using correlation and linear regression analysis. PA stiffness was significantly increased in HF patients compared to controls (RAC 30.92 ± 8.47 vs. 50.08 ± 9.08%, p < 0.001). PA blood flow parameters were significantly altered in HF patients (PWV 3.03 ± 0.53 vs. 2.11 ± 0.48, p < 0.001). These results were consistent in all three HF groups (HFrEF, HFmrEF and HFpEF) compared to the control group. Furthermore, PA stiffness was associated with higher NT-proBNP levels and a reduced functional status. PA stiffness can be assessed non-invasively by CMR. PA stiffness is increased in HFrEF, HFmrEF and HFpEF patients when compared to control subjects.Trial registration The study was registered at the German Clinical Trials Register (DRKS, registration number: DRKS00015615).

Diastolic exercise stress testing in heart failure with preserved ejection fraction: The DEST-HF study

AIMS

Pulmonary capillary wedge pressure (PAWP) ≥25 mmHg during bicycle ergometry is recommended to uncover occult heart failure with preserved ejection fraction. We hypothesized that PAWP increase would differ in available diastolic stress tests and that the margin of PAWP ≥25 mmHg would only be reliably achieved through ergometry.

METHODS AND RESULTS

We conducted a prospective, single-arm study in patients with an intermediate risk for heart failure with preserved ejection fraction according to the ESC HFA-PEFF score. A total of 19 patients underwent four stress test modalities in randomized order: leg raise, fluid challenge, handgrip, and bicycle ergometry. The primary outcome was the difference (Δ) between resting and exercise PAWP in each modality. Secondary outcomes were differences (Δ) in mean pulmonary artery pressure (mPAP), cardiac output (CO), as well as the ratios between mPAP and PAWP to CO. Compared to resting values, passive leg raise (Δ7.7 ± 8.0 mmHg, p = 0.030), fluid challenge (Δ9.2 ± 6.4 mmHg, p = 0.003), dynamic handgrip (Δ9.6 ± 7.5 mmHg, p = 0.002), and bicycle ergometry (Δ22.3 ± 5.0 mmHg, p < 0.001) uncovered increased PAWP during exercise. Amongst these, bicycle ergometry also demonstrated the highest ΔmPAP (27.2 ± 7.1 mmHg, p < 0.001), ΔCO (3.3 ± 2.6 L/min, p < 0.001), ΔmPAP/CO ratio (2.3 ± 2.0 mmHg/L/min, p < 0.001), and ΔPAWP/CO ratio (2.2 ± 1.4 mmHg/L/min, p < 0.001) compared to other modalities. PAWP ≥25 mmHg was only reliably achieved in bicycle ergometry (31.1 ± 3.9 mmHg). In all other modalities only 10.5% of patients achieved PAWP ≥25 mmHg (handgrip 18.4 ± 6.6 mmHg, fluid 18.1 ± 5.6 mmHg, leg raise 16.5 ± 7.0 mmHg).

CONCLUSIONS

We demonstrate that bicycle ergometry exhibits a distinct haemodynamic response with higher increase of PAWP compared to other modalities. This finding needs to be considered for valid detection of exercise PAWP ≥25 mmHg when non-bicycle tests remain inconclusive.

Paradoxical increase in global longitudinal strain by handgrip exercise despite left ventricular diastolic dysfunction

BACKGROUND

Although global longitudinal strain (GLS) is recognized as a sensitive marker of intrinsic left ventricular (LV) dysfunction, its afterload dependency has also been pointed. We hypothesized that decrease in GLS during handgrip exercise could be more sensitive marker of intrinsic myocardial dysfunction.

METHODS

Handgrip exercise-stress echocardiography was performed in 90 cardiovascular disease patients with preserved LV ejection fraction. LV diastolic function was graded according to the guidelines. Diastolic wall stress (DWS) and ratio of left atrial (LA) volume index to late-diastolic mitral annular velocity (LAVI/a') were measured at rest as LV stiffness. As well, LA strains were measured to assess LA function. GLS was expressed as absolute value and significant changes in GLS by handgrip exercise was defined as changes over prespecified mean absolute test-retest variability (2.65%).

RESULTS

While mean value of GLS did not change by the exercise, substantial patients showed significant changes in GLS: decreased (group I, n = 28), unchanged (group II, n = 34), and increased (group III, n = 28). Unexpectedly, patients in group I did not show any clinical and echocardiographic characteristics, while those in group III were characterized by elevated natriuretic peptide levels, blunted heart rate response to handgrip exercise, and advanced LV diastolic dysfunction. Multivariable analyses revealed that DWS, left atrial booster strain, and grade II or more diastolic dysfunction determined the increase in GLS even after adjustment for elevated natriuretic peptides and the changes in heart rate by the exercise.

CONCLUSION

In contrast to our hypothesis, paradoxical increase in GLS by handgrip exercise could be associated with advanced LV diastolic dysfunction in cardiovascular patients with preserved LV ejection fraction. Our findings suggest that HG exercise for heart failure patients does not enhance the afterload straightforward, resulting in variable changes of GLS according to the individual conditions.

Afterload increase challenge unmasks systolic abnormalities in heart failure with preserved ejection fraction

BACKGROUND

Provocative maneuvers have the potential to overcome the low sensitivity of resting echocardiography and biomarkers in the detection of heart failure with preserved ejection fraction (HFpEF). We investigate the mechanical response of the left ventricle to an afterload challenge in patients with preclinical and early-stage HFpEF (es-HFpEF).

METHODS

Three groups of patients (non-HFpEF - n = 42, pre-HFpEF - n = 43, and es-HFpEF - n = 39) underwent echocardiography at rest and during an afterload challenge induced by handgrip maneuver combined with pneumatic constriction of limbs.

RESULTS

Patients in the non-HF group displayed a median ΔLPSS = -4% (IQR: -10%, +2%), LPSS rest<16% in 3/42(7%) and LPSS stress<16% in 6/43(14%). Subjects in the pre-HFpEF group displayed median ΔLPSS = -3% (IQR: -10%, +5%) LPSS rest<16% in 13/43(30%) and LPSS stress<16% in 19/43 (44%). 11/43 (25%) subjects in this group increased at least one absolute point in LPSS during stress. Patients in es-HFpEF group displayed a median ΔLPSS = -10% (IQR: -18%, -1%), LPSS rest<16% in 15/39(38%) and LPSS stress<16% in 25/39(64%). Changes in LPSS (ΔLPSS) were significantly greater in es-HFpEF than pre-HFpEF (p = 0.022). In multivariate analysis, this group effect was maintained after adjustment of the LPSS for systolic blood pressure, use of β-blockers, LV mass, RWT, age, and sex.

CONCLUSION

Our data suggest that patients with HFpEF have a marked decrease in peak strain during acute pressure overload. Longitudinal studies are needed to test and compare the clinical impact of each pattern in early and long-term follow-ups.

Reduced functional capacity is associated with the proportion of impaired myocardial deformation assessed in heart failure patients by CMR

Aims

Heart failure (HF) does not only reduce the life expectancy in patients, but their life is also often limited by HF symptoms leading to a reduced quality of life (QoL) and a diminished exercise capacity. Novel parameters in cardiac imaging, including both global and regional myocardial strain imaging, promise to contribute to better patient characterization and ultimately to better patient management. However, many of these methods are not part of clinical routine yet, their associations with clinical parameters have been poorly studied. An imaging parameters that also indicate the clinical symptom burden of HF patients would make cardiac imaging more robust toward incomplete clinical information and support the clinical decision process.

Methods and results

This prospective study conducted at two centers in Germany between 2017 and 2018 enrolled stable outpatient subjects with HF [n = 56, including HF with reduced ejection fraction (HFrEF), HF with mid-range ejection fraction (HFmrEF), and HF with preserved ejection fraction (HFpEF)] and a control cohort (n = 19). Parameters assessed included measures for external myocardial function, for example, cardiac index and myocardial deformation measurements by cardiovascular magnetic resonance imaging, left ventricular global longitudinal strain (GLS), the global circumferential strain (GCS), and the regional distribution of segment deformation within the LV myocardium, as well as basic phenotypical characteristics including the Minnesota Living with Heart Failure Questionnaire (MLHFQ) and the 6-minute walk test (6MWT). If less than 80% of the LV segments are preserved in their deformation capacity the functional capacity by 6MWT (6 minutes walking distance: MyoHealth ≥ 80%: 579.8 ± 177.6 m; MyoHealth 60-<80%: 401.3 ± 121.7 m; MyoHealth 40-<60%: 456.4 ± 68.9 m; MyoHealth < 40%: 397.6 ± 125.9 m, overall p-value: 0.03) as well as the symptom burden are significantly impaired (NYHA class: MyoHealth ≥ 80%: 0.6 ± 1.1 m; MyoHealth 60-<80%: 1.7 ± 1.2 m; MyoHealth 40-<60%: 1.8 ± 0.7 m; MyoHealth < 40%: 2.4 ± 0.5 m; overall p-value < 0.01). Differences were also observed in the perceived exertion assessed by on the Borg scale (MyoHealth ≥ 80%: 8.2 ± 2.3 m; MyoHealth 60-<80%: 10.4 ± 3.2 m; MyoHealth 40-<60%: 9.8 ± 2.1 m; MyoHealth < 40%: 11.0 ± 2.9 m; overall p-value: 0.20) as well as quality of life measures (MLHFQ; MyoHealth ≥ 80%: 7.5 ± 12.4 m; MyoHealth 60-<80%: 23.4 ± 23.4 m; MyoHealth 40-<60%: 20.5 ± 21.2 m; MyoHealth < 40%: 27.4 ± 24.4 m; overall p-value: 0.15)-while these differences were not significant.

Conclusion

The share of LV segments with preserved myocardial contraction promises to discriminate between symptomatic and asymptomatic subjects based on the imaging findings, even when the LV ejection fraction is preserved. This finding is promising to make imaging studies more robust toward incomplete clinical information.

CMR detects decreased myocardial deformation in asymptomatic patients at risk for heart failure

Aims

The main management strategy of heart failure with preserved ejection fraction (HFpEF) is prevention since HFpEF is associated with many cardiovascular (CV) risk factors, especially since HFpEF is linked to a high risk for both mortality and recurrent heart failure (HF) hospitalizations. Therefore, there is a need for new tools to identify patients with a high risk profile early. Regional strain assessment by CMR seems to be superior in describing deformation impairment in HF. The MyoHealth score is a promising tool to identify cardiac changes early.

Methods and results

Heart failure patients irrespective of LVEF and asymptomatic controls were recruited, and CMR based measures were obtained. For this analysis the asymptomatic control group (n = 19) was divided into asymptomatic subjects without CV co-morbidities or evidence of cardiac abnormalities and (n = 12) and asymptomatic subjects with CV co-morbidities or evidence of cardiac abnormalities (n = 7) as well as patients with HFpEF (n = 19). We performed CMR scans at rest and during a stress test using isometric handgrip exercise (HG). Assessing the MyoHealth score at rest revealed preserved regional strain in 85 ± 9% of LV segments in controls, 73 ± 11% in at Risk subjects and 73 ± 8% in HFpEF patients. During stress the MyoHealth score was 84 ± 7% in controls, 83 ± 7 in at risk subjects and 74 ± 11 in HFpEF patients.

Conclusion

In summary, we show for the first time that asymptomatic subjects with increased CV risk present with HFpEF like impaired myocardial deformation at rest, while they show results like controls under HG stress. The potential of preventive treatment in this group of patients merits further investigation in future.

Clinical trial registration

[https://drks.de/search/de/trial/DRKS00015615], identifier [DRKS00015615].

[The Valsalva load test and spectral tracking echocardiography effectiveness in the diagnosis of heart failure with preserved left ventricular ejection fraction]

Aim      To determine the applicability of speckle-tracking EchoCG (STE) and the Valsalva maneuver for diagnosis of heart failure with preserved left ventricular ejection fraction (CHFpEF).Material and methods  Transthoracic STE with simultaneous electrocardiogram (ECG) recording was performed for patients with CHFpEF and healthy sex- and age-matched subjects (control group) at rest and during the Valsalva maneuver. The study was conducted in compliance with standards of Good Clinical Practice and principles of the Helsinki Declaration. The study protocol was approved by the Ethical Committee of the St. Petersburg State University.Results During the Valsalva maneuver, deviations of both global and segmental myocardial strain were more pronounced than at rest. In patients of the study group performing the Valsalva maneuver, LV end-diastolic volume and LV end-systolic volume (99 %) were increased. Heart rate was considerably reduced (significance of difference &gt;99%) in patients with CHFpEF during the Valsalva maneuver compared to the control group. The increased predictive value of these parameters during the Valsalva maneuver can justify the inclusion of this method in early detection and prognostic assessment of CHFpEF.Conclusion      Speckle-tracking EchoCG with the Valsalva maneuver is a noninvasive, generally available, and easily reproducible outpatient method for diagnosis of CHFpEF.

Hemodynamic Changes During Physiological and Pharmacological Stress Testing in Patients With Heart Failure: A Systematic Review and Meta-Analysis

Although disease etiologies differ, heart failure patients with preserved and reduced ejection fraction (HFpEF and HFrEF, respectively) both present with clinical symptoms when under stress and impaired exercise capacity. The extent to which the adaptation of heart rate (HR), stroke volume (SV), and cardiac output (CO) under stress conditions is altered can be quantified by stress testing in conjunction with imaging methods and may help to detect the diminishment in a patient’s condition early. The aim of this meta-analysis was to quantify hemodynamic changes during physiological and pharmacological stress testing in patients with HF. A systematic literature search (PROSPERO 2020:CRD42020161212) in MEDLINE was conducted to assess hemodynamic changes under dynamic and pharmacological stress testing at different stress intensities in HFpEF and HFrEF patients. Pooled mean changes were estimated using a random effects model. Altogether, 140 study arms with 7,248 exercise tests were analyzed. High-intensity dynamic stress testing represented 73% of these data (70 study arms with 5,318 exercise tests), where: HR increased by 45.69 bpm (95% CI 44.51–46.88; I2 = 98.4%), SV by 13.49 ml (95% CI 6.87–20.10; I2 = 68.5%), and CO by 3.41 L/min (95% CI 2.86–3.95; I2 = 86.3%). No significant differences between HFrEF and HFpEF groups were found. Despite the limited availability of comparative studies, these reference values can help to estimate the expected hemodynamic responses in patients with HF. No differences in chronotropic reactions, changes in SV, or CO were found between HFrEF and HFpEF. When compared to healthy individuals, exercise tolerance, as well as associated HR and CO changes under moderate-high dynamic stress, was substantially impaired in both HF groups. This may contribute to a better disease understanding, future study planning, and patient-specific predictive models.

Systematic Review Registration

[https://www.crd.york.ac.uk/prospero/], identifier [CRD42020161212].

Dynamic Handgrip Exercise: Feasibility and Physiologic Stress Response of a Potential Needle-Free Cardiac Magnetic Resonance Stress Test

Background: Cardiac magnetic resonance (CMR) pharmacological stress-testing is a well-established technique for detecting myocardial ischemia. Although stressors and contrast agents seem relatively safe, contraindications and side effects must be considered. Substantial costs are further limiting its applicability. Dynamic handgrip exercise (DHE) may have the potential to address these shortcomings as a physiological stressor. We therefore evaluated the feasibility and physiologic stress response of DHE in relation to pharmacological dobutamine-stimulation within the context of CMR examinations.

Methods: Two groups were prospectively enrolled: (I) volunteers without relevant disease and (II) patients with known CAD referred for stress-testing. A both-handed, metronome-guided DHE was performed over 2 min continuously with 80 contractions/minute by all participants, whereas dobutamine stress-testing was only performed in group (II). Short axis strain by fast-Strain-ENCoded imaging was acquired at rest, immediately after DHE and during dobutamine infusion.

Results: Eighty middle-aged individuals (age 56 ± 17 years, 48 men) were enrolled. DHE triggered significant positive chronotropic (HR_rest: 68 ± 10 bpm, HR_DHE: 91 ± 13 bpm, p < 0.001) and inotropic stress response (GLS_rest: −19.4 ± 1.9%, GLS_DHE: −20.6 ± 2.1%, p < 0.001). Exercise-induced increase of longitudinal strain was present in healthy volunteers and patients with CAD to the same extent, but in general more pronounced in the midventricular and apical layers (p < 0.01). DHE was aborted by a minor portion (7%) due to peripheral fatigue. The inotropic effect of DHE appears to be non-inferior to intermediate dobutamine-stimulation (GLS_DHE= −19.5 ± 2.3%, GLS_Dob= −19.1 ± 3.1%, p = n.s.), whereas its chronotropic effect was superior (HR_DHE= 89 ± 14 bpm, HR_Dob= 78 ± 15 bpm, p < 0.001).

Conclusions: DHE causes positive ino- and chronotropic effects superior to intermediate dobutamine-stimulation, suggesting a relevant increase of myocardial oxygen demand. DHE appears to be safe and timesaving with broad applicability. The data encourages further studies to determine its potential to detect obstructive CAD.

Myocardial deformation assessed among heart failure entities by cardiovascular magnetic resonance imaging

AIMS

Although heart failure (HF) is a leading cause for hospitalization and mortality, normalized and comparable non-invasive assessment of haemodynamics and myocardial action remains limited. Moreover, myocardial deformation has not been compared between the guideline-defined HF entities. The distribution of affected and impaired segments within the contracting left ventricular (LV) myocardium have also not been compared. Therefore, we assessed myocardial function impairment by strain in patients with HF and control subjects by magnetic resonance imaging after clinically phenotyping these patients.

METHODS AND RESULTS

This prospective study conducted at two centres in Germany between 2017 and 2018 enrolled stable outpatient subjects with HF [n = 56, including HF with reduced ejection fraction (HFrEF), HF with mid-range ejection fraction (HFmrEF), and HF with preserved ejection fraction (HFpEF)] and a control cohort (n = 12). Parameters assessed included measures for external myocardial function, for example, cardiac index and myocardial deformation measurements by cardiovascular magnetic resonance imaging, left ventricular global longitudinal strain (GLS), the global circumferential strain (GCS) and the regional distribution of segment deformation within the LV myocardium, as well as basic phenotypical characteristics. Comparison of the cardiac indices at rest showed no differences neither between the HF groups nor between the control group and HF patients (one-way ANOVA P = 0.70). The analysis of the strain data revealed differences between all groups in both LV GLS (One-way ANOVA: P < 0.01. Controls vs. HFpEF: -20.48 ± 1.62 vs. -19.27 ± 1.25. HFpEF vs. HFmrEF: -19.27 ± 1.25 vs. -15.72 ± 2.76. HFmrEF vs. HFrEF: -15.72 ± 2.76 vs. -11.51 ± 3.97.) and LV GCS (One-way ANOVA: P < 0.01. Controls vs. HFpEF: -19.74 ± 2.18 vs. -17.47 ± 2.10. HFpEF vs. HFmrEF: -17.47 ± 2.10 vs. -12.78 ± 3.47. HFrEF: -11.41 ± 3.27). Comparing the segment deformation distribution patterns highlighted the discriminating effect between the groups was much more prominent between the groups (one-way ANOVA P < 0.01) when compared by a score combining regional effects and a global view on the LV. Further analyses of the patterns among the segments affected showed that while the LVEF is preserved in HFpEF, the segments impaired in their contractility are located in the ventricular septum. The worse the LVEF is, the more segments are affected, but the septum remains an outstanding location with the most severe contractility impairment throughout the HF entities.

CONCLUSIONS

While cardiac index at rest did not differ significantly between controls and stable HF patients suffering from HFrEF, HFmrEF, or HFpEF, the groups did differ significantly in LV GLS and LV GCS values. Regional strain analysis revealed that the LV septum is the location affected most, with reduced values already visible in HFpEF and further reductions in HFmrEF and HFrEF.