Prognostic value of myocardial ischemic electrocardiographic response in patients with normal stress echocardiographic study

Significance of abnormal stress electrocardiography with normal cardiac imaging during stress testing-a meta-analysis

BACKGROUND AND AIMS

Diagnostic testing for coronary artery disease frequently involves functional stress testing where imaging is often coupled with electrocardiogram (ECG) analysis. While decision-making is straightforward when both functional testing and ECG are either positive or negative, interpretation is challenging and prognostic importance uncertain with positive ECG and negative imaging since imaging is considered more sensitive. Prior studies have demonstrated mixed results. We sought to perform a meta-analysis of published studies to determine the significance of this particular type of discordant stress test result.

METHODS AND RESULTS

PubMed, Cochrane, and Google Scholar were searched to identify studies reporting results of functional imaging (pharmacological exercise echocardiography or SPECT) and ECG analysis, along with the major adverse cardiovascular events (MACE) at patient follow-up. Studies were stratified based on functional imaging modality used. Primary outcome was a composite of all-cause death or myocardial infarction, and secondary outcome was the need for coronary revascularization. Random effects model was used to calculate risk ratios (RR), and heterogeneity among studies was assessed using the Higgins I2 value. Nine studies with a total of 23,715 patients were included. Primary end point was more common with discordant results with exercise stress echocardiography (RR 1.33, 95% confidence intervals [1.08-1.63]) or pharmacological SPECT (RR 6.53 95% CI [2.31-18.48]).

CONCLUSIONS

Patients in the discordant exercise stress echocardiography and pharmacological SPECT groups were more likely to suffer the primary end point than those with a normal stress test. Discordant results should be interpreted carefully in the clinical context, given their prognostic impact based on the stress modality used.

Prognostic impact of stress echocardiography with discordant stress electrocardiography in patients with suspected coronary artery disease

INTRODUCTION

During stress echocardiography, the echocardiologist routinely collects both echocardiographic images and stress electrocardiogram (ECG) concurrently. The managing physician faces a dilemma when the stress ECG and stress echocardiography results are discordant; for example, when a patient has negative stress echocardiography but positive stress ECG. We therefore sought to evaluate the prognostic value of stress echocardiography in relation to concordant or discordant stress ECG findings in our local Singapore setting, which has a well-defined Southeast Asian population.

METHODS

This was a retrospective observational study of all patients who underwent stress echocardiography in 2012 at Changi General Hospital, Singapore. All study patients were followed up for 18 months via electronic medical records.

RESULTS

There was no difference in the major adverse cardiovascular events (MACE) outcome of patients with normal stress echocardiography and normal stress ECG (reference group) as compared with patients with normal stress echocardiography but positive (discordant) stress ECG (odds ratio 2.02, 95% confidence interval 0.82‒4.98; p = 0.125).

CONCLUSION

This study will help to reassure cardiologists that discordant results (negative stress echocardiography but positive stress ECG) do not portend a higher risk of MACE when compared to concordant results (i.e. both stress echocardiography and stress ECG are negative).

Influence of Cardiovascular Risk in the Prediction and Timing of Cardiac Events After Exercise Echocardiogram Testing Without Ischemia

INTRODUCTION AND OBJECTIVES

There have been no analyses of the influence of cardiovascular risk as a predictor of events in patients with exercise echocardiography (EE) without ischemia. Our objective was to determine the predictors of cardiac events, paying special attention to cardiovascular risk.

METHODS

This study included 1640 patients with EE without ischemia. Of these, there were 1206 with no previously known coronary artery disease (CAD), whose risk of a fatal cardiovascular disease event was estimated according to the European SCORE (Systematic COronary Risk Evaluation) risk assessment system, and 434 with known CAD. The primary endpoint was cardiac event-free survival (EFS) (cardiac death, nonfatal acute coronary syndrome, and coronary revascularization).

RESULTS

After a median follow-up of 35 [23-54] months, no differences were found in cardiac EFS between patients with a SCORE ≥ 10 or diabetes and patients with previous CAD (89.8% vs 87.1%). In the first year, cardiac EFS was high in all groups (99.4% if SCORE < 5; 100% if 5-9; 98% if ≥ 10 or diabetes and 97% in patients with CAD). In the third year, cardiac EFS was similar in the group with SCORE ≥ 10 or diabetes (94.5%) and patients with CAD (91.1%, P = NS). In these patients, the annualized event rate was 2.8% and 2.55%, respectively, and was significantly higher than in groups with SCORE < 5 (0.6%) and SCORE 5-9 (0.12%). The most frequent events were non-ST-segment elevation acute coronary syndrome and late revascularization. Predictors of cardiac events were previous CAD, SCORE ≥ 10 or diabetes mellitus, creatinine clearance, left ventricular ejection fraction, and chest pain during EE.

CONCLUSIONS

Initial outcome after an EE without ischemia is favorable but is subsequently modulated by cardiovascular risk.