Impaired resting myocardial annular velocities are independently associated with mental stress-induced ischemia in coronary heart disease

Abstract

Objectives: The aim of this study was to investigate the association between resting myocardial function as assessed by tissue Doppler myocardial velocities and the propensity to develop mental stress-induced ischemia (MSIMI).

Background: Tissue Doppler myocardial velocities detect preclinical cardiac dysfunction and clinical outcomes in a range of conditions. However, little is known about the interrelationship between myocardial velocities and the propensity to develop MSIMI compared with exercise stress-induced myocardial ischemia.

Methods: Resting annular myocardial tissue Doppler velocities were obtained in 225 patients with known coronary heart disease who were subjected to both conventional exercise stress testing as well as a battery of 3 mental stress tests. Diastolic early (e') and late (a') as well as systolic (s') velocities were obtained, and the eas index, an integrated measure of myocardial velocities, was calculated as e'/(a' × s'). MSIMI was defined as: 1) the development or worsening of regional wall motion abnormality; 2) a reduction in left ventricular ejection fraction ≥ 8%; and/or 3) ischemic ST-segment changes during 1 or more of the 3 mental stress tests.

Results: A total of 98 of 225 patients (43.7%) exhibited MSIMI. Patients developing MSIMI had significantly lower s' (7.0 ± 1.7 vs. 7.5 ± 1.2, p = 0.016) and a' (8.9 ± 1.8 vs. 10.0 ± 1.9, p < 0.001) at baseline, whereas e' did not differ (6.5 ± 1.7 vs. 6.5 ± 1.8, p = 0.85). Furthermore, the eas index was significantly higher (0.11 ± 0.04 vs. 0.09 ± 0.03, p < 0.0001). The eas index remained significantly associated with the propensity to develop MSIMI (odds ratio per 0.05-U increase: 1.85; 95% confidence interval: 1.21 to 2.82; p = 0.004) after adjustment for resting left ventricular ejection fraction, resting wall motion index score, sex, and social circumstances of living. There was no association between resting eas index and exercise stress-induced myocardial ischemia.

Conclusions: MSIMI but not exercise stress-induced myocardial ischemia is independently associated with resting abnormalities in myocardial systolic and late diastolic velocities as well as the integrated measure of the eas index in patients with known coronary artery disease. (Responses of Myocardial Ischemia to Escitalopram Treatment [REMIT]; NCT00574847).

Keywords: echocardiography; mental stress–induced ischemia; tissue Doppler.

Conflict of interest statement

Disclosures: The authors report the following potential conflicts of interest: Dr. Samad is a sub-investigator for the REALISM (Everest II Real World ExpAnded MuLtIcenter Study of the MitraClip System) funded by Abbott Vascular. Dr. O’Connor is a co-owner of Biscardia, a stockholder in Neurotronik/Interventional Autonomics Corporation (Stockholder), and has received financial support from Actelion Pharmaceuticals, Amgen, Astellas Pharma, BG Medicine, Critical Diagnostics, GE Healthcare, Gilead Sciences, HeartWare, Ikaria, Johnson & Johnson, Novartis, Otsuka Pharmaceutical Company, Pfizer, Pozen, ResMed, and Roche Diagnostics. Dr. Velazquez is a consultant for Novartis, and has received research grants from Abbott Vascular and Ikaria Pharmaceuticals. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.

Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Figures

Figure 1. Example of different annular myocardial velocity pattern in patients with- and without MSIMI

Example of two patients exhibiting differential patterns of response towards mental stress- and exercise stress test. Patient A (Top) had preserved myocardial velocities at baseline with an eas-index (e′/(a′x s′)) of 0.06 and had a positive exercise stress test but negative mental stress test (isolated ESIMI). Patient B (bottom) had impaired baseline myocardial velocities with a markedly reduced s′ and an eas-index of 0.15 and experienced isolated MSIMI. Both patient A and patient B had preserved LVEF (61% and 57% respectively).

Figure 2. Positive mental stress tasks according to resting eas-index

Cumulative number of positive mental stress tasks according to tertiles of resting eas-index.

Figure 3. Positive response to mental stress tasks according to resting eas-index

Distribution of mental stress induced ischemia by mental stress task according to tertiles of resting eas-index.

Figure 4. eas-index during mental stress tests

Relationship between the eas-index obtained at each mental stress task according to whether patients developed MSIMI.

Figure 5. Pattern of annular myocardial velocities during mental stress

Relationship between myocardial annular velocities (e′, a′ and s′) obtained at each mental stress task according to whether the patient developed MSIMI.