*Corresponding author:
Jesús Peteiro, Department of Cardiology, Hospital Universitario de A Coruña, (CHUAC), A Coruña, SpainReceived: January 21, 2018; Published: February 01, 2018
DOI: 10.26717/BJSTR.2018.02.000717
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Objective: There is limited information about the value of exercise echocardiography for the prediction of events after coronary artery by-pass surgery (CABS). Ischemia might be considered of limited value in patients already revascularized by surgery. We sought to investigate the value of exercise echocardiography (ExE) for the prediction of major cardiac events (MACE) and overall mortality in patients submitted to CABS.
Methods: Retrospective analysis of prospectively collected data on 568 CABS patients (mean age 66±10 years) who were submitted to a clinically indicated first treadmill ExE. Normal ExE was defined as the absence of wall motion abnormalities (WMAs) at rest and at exercise. Ischemia was defined as the appearance of new WMAs or the worsening of resting WMAs. Abnormal ExE was defined as ischemia or the presence of resting WMAs unchanged with exercise. The end points were MACE and overall mortality.
Results: During a mean follow-up of 6.6±5.4 years, there were 132 MACE before any subsequent revascularization and 196 deaths. An abnormal ExE was observed in 432 patients (76%) and ischemia in 274 (48%). After multivariate adjustment that included clinical characteristics, resting left ventricular function and exercise ECG testing results, ischemia during ExE was an independent predictor of MACE (Hazard ratio [HR]=1.64, 95% Confidence Interval [CI]=1.15-2.34, p=0.006), and a marginally predictor of overall mortality (HR=1.34, 95% Confidence Interval [CI]=1.00-1.78, p=0.05). Other predictors of MACE were resting left ventricular ejection fraction and maximal achieved workload in metabolic equivalents. Annualized MACE rates were double in patients with ischemia in comparison to patients without (6.8% vs. 3.4%, p<0.001), and quadruple in patients with abnormal ExE in comparison to those with a normal ExE (6.0% vs. 1.9%, p<0.001).
Conclusions: An abnormal ExE is prevalent among surgical revascularized patients with clinically indicated ExE, and is a predictor of events.
Keywords: Exercise echocardiography; by-pass surgery; ischemia
Abbreviations: BP: Blood pressure; CABS: Coronary artery by-pass surgery; CAD: Coronary artery disease; ECG: Electrocardiogram; ExE: Exercise echocardiography; LVEF: Left ventricular ejection fraction; MACE: Major cardiac events; MAPHR: Mean age-predicted heart rate; MI: Myocardial infarction; WMAs: Wall motion abnormalities; WMSI: Wall motion score index; RASS denotes renin-angiotensin-aldosterone system; IMA: internal mammary artery; METs denotes metabolic equivalents; RPP, rate pressure product (1000 mmHg x beats/min);
Abstract| Introduction| Methods| Patients| Exercise ECG Testing| Exercise echocardiography and echocardiographic analysis| Follow-Up and End-Points| Statistical Analysis| Results| Discussion| Limitations| Clinical Implications| References|