Abstract
Background: Abnormal left ventricular systolic and diastolic function and reduced exercise capacity are associated with worse prognosis following ST-elevation myocardial infarction (STEMI). However, evidence is lacking on the determinants of exercise capacity following STEMI. We sought to determine the impact of systolic and diastolic dysfunction on exercise capacity and outcomes following first-ever STEMI. Methods: In a retrospective analysis of 139 consecutive STEMI patients who had a transthoracic echocardiogram following STEMI and completed exercise treadmill testing, the primary outcome was to identify clinical and echocardiographic determinants of exercise capacity, and the secondary outcome was to identify determinants of major adverse cardiac events (MACEs). Results: Mean number of metabolic equivalents (METs > 8) was used as a cut-off. Age, female sex, anterior infarction, abnormal diastolic function, minimum left atrial indexed volume (LAVImin) ≥ 18 mL/m2, average e’, and E/e’ were associated with METs ≤ 8, but not left ventricular ejection fraction (LVEF). On multivariate analysis, LAVImin (OR 4.3, 95%CI 1.3–14.2; p = 0.017), anterior infarction (OR 2.6, 95%CI 1.2–5.9; p = 0.022), and abnormal diastolic function (OR 3.73, 95%CI 1.7–8.4; p = 0.001) were independent predictors of METs ≤ 8. On Kaplan–Meier analysis, METs ≤ 8 (p = 0.01) and abnormal diastolic function (p = 0.04) were associated with MACEs (median follow-up 2.3 years). METs ≤ 8 was an independent predictor of MACEs (HR 3.4, 95%CI 1.2–9.8; p = 0.02). Conclusions: Following first-ever STEMI, increased LAVImin, anterior infarction, and abnormal diastolic function were independent predictors of reduced exercise capacity. Furthermore, reduced exercise capacity was an independent predictor of MACEs. These results highlight important prognostic and therapeutic implications related to abnormal diastolic function in STEMI patients that are distinct from those with LV systolic impairment.
Highlights
Exercise capacity following acute ST-segment elevation myocardial infarction (STEMI)has been used as a surrogate marker and a predictor of poor outcomes [1,2,3]
The secondary objective was to determine the prognostic significance of reduced exercise capacity at Exercise treadmill testing (ETT) with major adverse cardiac events (MACEs), defined as the composite endpoint of cardiovascular hospitalisation for recurrent angina, acute coronary syndrome (ACS), heart failure, arrhythmias, and cardiovascular mortality
On multivariate analysis, metabolic equivalents (METs) ≤ 8 was an independent predictor of MACEs (HR 3.4, 95%CI 1.2–9.8; p = 0.02)
Summary
Exercise capacity following acute ST-segment elevation myocardial infarction (STEMI). A few studies have demonstrated that diastolic dysfunction may be a more important determinant of exercise capacity as compared to systolic function following myocardial infarction [6,8]. Current evidence on exercise capacity includes largely a heterogeneous postinfarct group that does not focus on acute STEMI patients [1,6,8,9]. These studies often include patients with remote myocardial infarction [6], do not comprise a contemporary cohort [9], and have relatively small sample sizes [1,6,9]. We hypothesised that measures of abnormal diastolic function may be more significant determinants of reduced exercise capacity as compared with systolic function
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
