The incremental prognostic value of pharmacological stress echo over exercise electrocardiography in women with chest pain of unknown origin

[The Clinical use of Stress Echocardiography in Ischemic Heart Disease Cardiovascular Ultrasound (2017)15:7. Translation authors: Arystan A.Zh., Fettser D.V.]

Stress echocardiography is an established technique for the assessment of extent and severity of coronary artery disease. The combination of echocardiography with a physical, pharmacological or electrical stress allows detecting myocardial ischemia with an excellent accuracy. A transient worsening of regional function during stress is the hallmark of inducible ischemia. Stress echocardiography provides similar diagnostic and prognostic accuracy as radionuclide stress perfusion imaging or magnetic resonance, but at a substantially lower cost, without environmental impact, and with no biohazards for the patient and the physician. The evidence on its clinical impact has been collected over 35 years, based on solid experimental, pathophysiological, technological and clinical foundations. There is the need to implement the combination of wall motion and coronary flow reserve, assessed in the left anterior descending artery, into a single test. The improvement of technology and in imaging quality will make this approach more and more feasible. The future issues in stress echo will be the possibility of obtaining quantitative information translating the current qualitative assessment of regional wall motion into a number. The next challenge for stress echocardiography is to overcome its main weaknesses: dependence on operator expertise, the lack of outcome data (a widespread problem in clinical imaging) to document the improvement of patient outcomes. This paper summarizes the main indications for the clinical applications of stress echocardiography to ischemic heart disease.

The clinical use of stress echocardiography in ischemic heart disease

Stress echocardiography is an established technique for the assessment of extent and severity of coronary artery disease. The combination of echocardiography with a physical, pharmacological or electrical stress allows to detect myocardial ischemia with an excellent accuracy. A transient worsening of regional function during stress is the hallmark of inducible ischemia. Stress echocardiography provides similar diagnostic and prognostic accuracy as radionuclide stress perfusion imaging or magnetic resonance, but at a substantially lower cost, without environmental impact, and with no biohazards for the patient and the physician.

The evidence on its clinical impact has been collected over 35 years, based on solid experimental, pathophysiological, technological and clinical foundations. There is the need to implement the combination of wall motion and coronary flow reserve, assessed in the left anterior descending artery, into a single test. The improvement of technology and in imaging quality will make this approach more and more feasible. The future issues in stress echo will be the possibility of obtaining quantitative information translating the current qualitative assessment of regional wall motion into a number. The next challenge for stress echocardiography is to overcome its main weaknesses: dependance on operator expertise, the lack of outcome data (a widesperad problem in clinical imaging) to document the improvement of patient outcomes. This paper summarizes the main indications for the clinical applications of stress echocardiography to ischemic heart disease.

At the Heart of the Matter

Echocardiography is an excellent method for evaluating cardiac morphology and dynamic function. It has a long history of innovative thinking mixed with some degree of serendipity. Its early applications were as a tool to evaluate the mitral valve, left ventricular characteristics, and pericardial effusion. Today it has evolved into a robust modality that allows for a very wide range cardiac interrogation, able to evaluate the valves, chambers, myocardium, and pericardium. The practice of echocardiography also is often separate from that of general or vascular sonography. The objective of this article is to provide the non–cardiac sonographer with an overview and appreciation of the basic principles and practices of echocardiography. It is not meant as a guide to scanning but rather, as a vehicle to spark the interest and imagination of the reader.

Role of echocardiography in the management of cardiac disease in women

The widespread use of echocardiography has contributed to the early recognition of several distinct cardiac diseases in women. During pregnancy, safe monitoring of the disease process, as well as a better understanding of hemodynamics, is possible. During the use of potentially cardiotoxic drugs for breast cancer chemotherapy, echocardiographic patient monitoring is vital. Compared to men, the addition of an imaging modality to routine electrocardiogram monitoring during stress testing is more informative for diagnosing coronary disease in women. This review briefly discusses the role of echocardiography in the management of several women-specific cardiac diseases where echocardiography plays a pivotal role in disease management.

Impact of gender on risk stratification by stress echocardiography

OBJECTIVE

To compare the prognostic value of stress echocardiography results in men and women with known and suspected coronary artery disease.

METHODS

We analyzed the data of 8737 patients (5529 men and 3208 women) who underwent stress echocardiography (exercise in 523 patients, dipyridamole in 6227 patients, dobutamine in 1987) for evaluating known (n=3857) or suspected (n=4880) coronary artery disease. Patients were followed up for the occurrence of overall mortality or nonfatal myocardial infarction.

RESULTS

During a median follow-up of 25 months, 1218 cardiac events (693 deaths and 525 infarctions) occurred. Moreover, 2263 patients (1731 men [31%] and 532 women [17%]; P<.0001) underwent coronary revascularization and were censored. Stress echocardiography results added prognostic information to that of clinical findings and resting wall motion score index in men and women with both known and suspected coronary artery disease. In patients with known coronary artery disease, women had a higher (P=.01) event rate than men in the presence of ischemia. The annual event rate was worse for nondiabetic women (P=.007) but not diabetic women; age had a neutral prognostic effect in the 2 sexes. In patients with suspected coronary artery disease, men without ischemia had a higher (P<.0001) event rate than women. The annual event rate was worse in men aged less than 65 years (P<.0001) or more than 65 years (P=.04), and those with (P=.03) or without (P<.0001) diabetes.

CONCLUSION

Prognosis is at least comparable in men and women with ischemia and in those with coronary artery disease and no ischemia at stress echocardiography. In these clinical settings, availability for major procedures should be similar for both genders.

Comparison of prognostic value of pharmacologic stress echocardiography in chest pain patients with versus without diabetes mellitus and positive exercise electrocardiography

The aim of this study was to compare the prognostic value of pharmacologic stress echocardiography in diabetic and nondiabetic patients with chest pain and intermediate- to high-threshold positive exercise electrocardiographic results. A total of 935 patients with chest pain (131 diabetic patients) with ST-segment depression > or =1 mm on exercise electrocardiography at > or =75-W workload underwent dipyridamole (n = 786) or dobutamine (n = 149) stress echocardiography and were followed up for the occurence of hard (death and infarction) and major events (death, infarction, and late revascularization). During a median follow-up of 26 months, 158 events (51 deaths, 28 myocardial infarctions, and 79 late revascularizations) occurred: 34 in diabetic and 124 in nondiabetic patients (26% vs 15%, p = 0.003). Independent predictors of hard events were age, diabetes, and ischemia at stress echocardiography. Five-year hard event rates were 24% in patients with and 4% in those without ischemia (p <0.0001). Independent predictors of major events were age, diabetes, hypercholesterolemia, smoking habit, antianginal therapy at the time of testing, and ischemia at stress echocardiography. Five-year major event rates were 46% in patients with and 7% in those without ischemia (p <0.0001). Stress echocardiography results yielded effective prognostic information in diabetic and nondiabetic patients. However, the latter had worse outcomes in both the presence and absence of ischemia. Nevertheless, a nonischemic test result predicted an uneventful 6-month period and 2% major event rate at 1-year follow-up in both populations. In conclusion, stress echocardiography was effective in risk stratifying diabetic and nondiabetic patients with intermediate- to high-threshold ischemic exercise electrocardiographic results. However, major event rates associated with a nonischemic test result were similar in diabetic and nondiabetic patients during the first year of follow-up and markedly increased in the former thereafter.

Risk Stratification Using Stress Echocardiography: Incremental Prognostic Value over Historic, Clinical, and Stress Electrocardiographic Variables Across a Wide Spectrum of Bayesian Pretest Probabilities for Coronary Artery Disease

OBJECTIVES

We sought to evaluate the risk stratification ability and incremental prognostic value of stress echocardiography over historic, clinical, and stress electrocardiographic (ECG) variables, over a wide spectrum of bayesian pretest probabilities of coronary artery disease (CAD).

BACKGROUND

Stress echocardiography is an established technique for the diagnosis of CAD. However, data on incremental prognostic value of stress echocardiography over historic, clinical, and stress ECG variables in patients with known or suggested CAD is limited.

METHODS

We evaluated 3259 patients (60 +/- 13 years, 48% men) undergoing stress echocardiography. Patients were grouped into low (<15%), intermediate (15-85%), and high (>85%) pretest CAD likelihood subgroups using standard software. The historical, clinical, stress ECG, and stress echocardiographic variables were recorded for the entire cohort. Follow-up (2.7 +/- 1.1 years) for confirmed myocardial infarction (n = 66) and cardiac death (n = 105) was obtained.

RESULTS

For the entire cohort, an ischemic stress echocardiography study confers a 5.0 times higher cardiac event rate than the normal stress echocardiography group (4.0% vs 0.8%/y, P < .0001). Furthermore, Cox proportional hazard regression model showed incremental prognostic value of stress echocardiography variables over historic, clinical, and stress ECG variables across all pretest probability subgroups (global chi2 increased from 5.1 to 8.5 to 20.1 in the low pretest group, P = .44 and P = .01; from 20.9 to 28.2 to 116 in the intermediate pretest group, P = .47 and P < .0001; and from 17.5 to 36.6 to 61.4 in the high pretest group, P < .0001 for both groups).

CONCLUSIONS

A normal stress echocardiography portends a benign prognosis (<1% event rate/y) in all pretest probability subgroups and even in patients with high pretest probability and yields incremental prognostic value over historic, clinical, and stress ECG variables across all pretest probability subgroups. The best incremental value is, however, in the intermediate pretest probability subgroup.

The Prognostic Value of Normal Exercise Myocardial Perfusion Imaging and Exercise Echocardiography

OBJECTIVES

The purpose of this work was to determine the prognostic value of normal exercise myocardial perfusion imaging (MPI) tests and exercise echocardiography tests, and to determine the prognostic value of these imaging modalities in women and men.

BACKGROUND

Exercise MPI and exercise echocardiography provide prognostic information that is useful in the risk stratification of patients with suspected coronary artery disease (CAD).

METHODS

We searched the PubMed, Cochrane, and DARE databases between January 1990 and May 2005, and reviewed bibliographies of articles obtained. We included prospective cohort studies of subjects who underwent exercise MPI or exercise echocardiography for known or suspected CAD, and provided data on primary outcomes of myocardial infarction (MI) and cardiac death with at least 3 months of follow-up. Secondary outcomes (unstable angina, revascularization procedures) were abstracted if provided. Studies performed exclusively in patients with CAD were excluded.

RESULTS

The negative predictive value (NPV) for MI and cardiac death was 98.8% (95% confidence interval [CI] 98.5 to 99.0) over 36 months of follow-up for MPI, and 98.4% (95% CI 97.9 to 98.9) over 33 months for echocardiography. The corresponding annualized event rates were 0.45% per year for MPI and 0.54% per year for echocardiography. In subgroup analyses, annualized event rates were <1% for each MPI isotope, and were similar for women and men. For secondary events, MPI and echocardiography had annualized event rates of 1.25% and 0.95%, respectively.

CONCLUSIONS

Both exercise MPI and exercise echocardiography have high NPVs for primary and secondary cardiac events. The prognostic utility of both modalities is similar for both men and women.

The use of stress echocardiography for prognostication in coronary artery disease: an overview

PURPOSE OF REVIEW

Stress echocardiography has a high accuracy for the detection of coronary artery disease. Additionally, it provides clinically useful prognostic information, such as resting left ventricular function, myocardial viability, stress-induced ischemia, vascular extent of wall motion abnormalities, and changes in end-systolic volume and ejection fraction with stress.

RECENT DEVELOPMENTS

The timing, extent, and severity of the stress-induced wall motion abnormalities are important determinants of long-term prognosis. Previous studies have shown the efficacy of stress echocardiography in predicting long-term cardiac events in mixed patient groups and the value of this test in selected patient subsets.

SUMMARY

This review attempts to define the role of stress echocardiography for prognostication in coronary artery disease, pointing out the ability of this technique to identify low-risk and high-risk subsets among patients with known or suspected coronary artery disease and thus guide patient management decisions.

Impact of gender on risk stratification by exercise and dobutamine stress echocardiography: long-term mortality in 4234 women and 6898 men

AIMS

Prior research is limited with regard to the diagnostic and prognostic accuracy of commonplace cardiac imaging modalities in women. The aim of this study was to examine 5-year mortality in 4234 women and 6898 men undergoing exercise or dobutamine stress echocardiography at three hospitals.

METHODS AND RESULTS

Univariable and multivariable Cox proportional hazards models were used to estimate time to cardiac death in this multi-centre, observational registry. Of the 11 132 patients, women had a greater frequency of cardiac risk factors (P<0.0001). However, men more often had a history of coronary disease including a greater frequency of echocardiographic wall motion abnormalities (P<0.0001). During 5 years of follow-up, 103 women and 226 men died from ischaemic heart disease (P<0.0001). Echocardiographic estimates of left ventricular function (P<0.0001) and the extent of ischaemic wall motion abnormalities (P<0.0001) were highly predictive of cardiac death. Risk-adjusted 5-year survival was 99.4, 97.6, and 95% for exercising women with no, single, and multi-vessel ischaemia (P<0.0001). For women undergoing dobutamine stress, 5-year survival was 95, 89, and 86.6% for those with 0, 1, and 2-3 vessel ischaemia (P<0.0001). Exercising men had a 2.0-fold higher risk at every level of worsening ischaemia (P<0.0001). Significantly worsening cardiac survival was noted for the 1568 men undergoing dobutamine stress echocardiography (P<0.0001); no ischaemia was associated with 92% 5-year survival as compared with death rates of >/=16% for men with ischaemia on dobutamine stress echocardiography (P<0.0001).

CONCLUSION

Echocardiographic measures of inducible wall motion abnormalities and global and regional left ventricular function are highly predictive of long-term outcome for women and men alike.

Role of Dobutamine-Atropine Stress Echocardiography in Prognostic Evaluation of 300 Women

BACKGROUND

Dobutamine-atropine stress echocardiography (DASE) is a safe and accurate method to diagnose coronary artery disease (CAD), and can identify individuals at high risk for cardiac events such as myocardial infarction and cardiac-related death. The literature is limited regarding the prognostic value of DASE in women.

OBJECTIVE

The objective was to determine the prognostic value of DASE in 300 women with known or suspected CAD.

RESULTS

The 300 women underwent DASE and were followed up for 65 months (mean: 27 months). Ninety-five women had positive tests and 205 had negative tests. We demonstrated that women with negative tests had a 94% hard-event-free survival rate at follow-up (myocardial infarction and death), and in those with positive tests the event-free survival rate was 27% (P = 0.0003). The difference between women with positive and negative tests was also significant when minor events and total events were considered. Women with positive tests had 16.7 times more chance of having events than women with negative tests. Furthermore, women with positive tests but without cardiac events at follow-up (mean of peak WMSI - rest WMSI = 0.24 +/- 0.16) had less ischemic myocardium than women with positive tests and cardiac events at follow-up (mean of peak WMSI - rest WMSI = 0.34 +/- 0.26)(P < 0.04).

CONCLUSION

Dobutamine-atropine stress echocardiography has good prognostic value for cardiac events in women. Women with negative tests have low probability for follow-up infarction or death. Women with positive tests and higher severity of induced ischemia have the highest incidence of cardiac events.