Exercise stress echocardiography:Where are we now?

Exercise stress echocardiography(ESE)is a widely used diagnostic test in cardiology departments.ESE is mainly used to study patients with coronary artery disease;however,it has increasingly been used in other clinical scenarios including valve pathology,congenital heart disease,hypertrophic and dilated cardiomyopathies,athlete evaluations,diastolic function evaluation,and pulmonary circulation study.In our laboratories,we use an established methodology in which cardiac function is evaluated while exercising on a treadmill.After completing the exercise regimen,patients remain in a standing position or lie down on the left lateral decubitus,depending on the clinical questions to be answered for further evaluation.This method increases the quality and quantity of information obtained.Here,we present the various methods of exercise stress echocardiography and our experience in many clinical arenas in detail.We also present alternatives to ESE that may be used and their advantages and disadvantages.We review recent advances in ESE and future directions for this established method in the study of cardiac patients and underline the advantage of using a diagnostic tool that is radiation-free.

Prognostic value of left atrial size in hypertensive African Americans undergoing stress echocardiography

BACKGROUND Left atrial(LA)enlargement is a marker of increased risk in the general population undergoing stress echocardiography.African American(AA)patients with hypertension are known to have less atrial remodeling than whites with hypertension.The prognostic impact of LA enlargement in AA with hypertension undergoing stress echocardiography is uncertain.AIM To investigate the prognostic value of LA size in hypertensive AA patients undergoing stress echocardiography.METHODS This retrospective outcomes study enrolled 583 consecutive hypertensive AA patients who underwent stress echocardiography over a 2.5-year period.Clinical characteristics including cardiovascular risk factors,stress and echocardiographic data were collected from the electronic health record of a large community hospital.Treadmill exercise and Dobutamine protocols were conducted based on standard practices.Patients were followed for all-cause mortality.The optimal cutoff value of antero-posterior LA diameter for mortality was assessed by receiver operating characteristic analysis.Cox regression was used to determine variables associated with outcome.RESULTS The mean age was 57±12 years.LA dilatation was present in 9%(54)of patients(LA anteroposterior≥2.4 cm/m^(2)).There were 85 deaths(15%)during 4.5±1.7 years of follow-up.LA diameter indexed for body surface area had an area under the curve of 0.72±0.03(optimal cut-point of 2.05 cm/m^(2)).Variables independently associated with mortality included age[P=0.004,hazard ratio(HR)1.34(1.10-1.64)],tobacco use[P=0.001,HR 2.59(1.51-4.44)],left ventricular hypertrophy[P=0.001,HR 2.14(1.35-3.39)],Dobutamine stress[P=0.003,HR 2.12(1.29-3.47)],heart failure history[P=0.031,HR 1.76(1.05-2.94)],LA diameter≥2.05 cm/m^(2)[P=0.027,HR 1.73(1.06-2.82)],and an abnormal stress echocardiogram[P=0.033,HR 1.67(1.04-2.68)].LA diameter as a continuous variable was also independently associated with mortality but LA size≥2.40 cm/m^(2) was not.CONCLUSION LA enlargement is infrequent in hypertensive AA patients when traditional reference values are used.LA enlargement is independently associated with mortality when a lower than“normal”threshold(≥2.05 cm/m^(2))is used.

Cirrhotic cardiomyopathy:Isn't stress evaluation alwaysrequired for the diagnosis?

AIM:To describe the proportion of patients with cirrhotic cardiomyopathy(CCM) evaluated by stress echocardiography and investigating its association with the severity of liver disease.METHODS:A cross-sectional study was conducted.Cirrhotic patients without risk factors for cardiovascular disease were included.Data regarding etiology and severity of liver disease(Child-Pugh score and model for end-stage liver disease),presence of ascites and gastroesophageal varices,pro-brain natriuretic peptide(proBNP) and corrected QT(QTc) interval were collected.Dobutamine stress echocardiography(conventional and tissue Doppler imaging) was performed.CCM was considered present when diastolic and/or systolic dysfunction was diagnosed at rest or after pharmacological stress.Therapy interfering with cardiovascular system was suspended 24 h before the examination.RESULTS:Twenty-six patients were analyzed,17(65.4%) Child-Pugh A,mean model for end-stage liver disease(MELD) score of 8.7.The global proportion of patients with CCM was 61.5%.At rest,only 2(7.7%)patients had diastolic dysfunction and none of the patients had systolic dysfunction.Dobutamine stress echocardiography revealed the presence of diastolic dysfunction in more 6(23.1%) patients and of systolic dysfunction in 10(38.5%) patients.QTc interval prolongation was observed in 68.8%of the patients and increased pro-BNP levels in 31.2%of them.There was no association between the presence of CCM and liver impairment assessed by Child-Pugh score or MELD(P= 0.775,P= 0.532,respectively).Patients with QTc interval prolongation had a significant higher rate of gastroesophageal varices comparing with those without QTc interval prolongation(95.0%vs 50.0%,P= 0.028).CONCLUSION:CCM is a frequent complication of cirrhosis that is independent of liver impairment.Stress evaluation should always be performed,otherwise it will remain an underdiagnosed condition.

Relationship between exercise induced elevation of left ventricular filling pressure and exercise intolerance in patients with atrial fibrillation

Background Elevated left ventricular filling pressure （LVFP） is an important cause of exercise intolerance in patients with atrial fib- dilation （AF）. Exercise stress echocardiography could assess LVFP during exercise. The objective of this study was to investigate the relationship between exercise induced elevation of LVFP and exercise capacity in patients with AF. Methods This study included 145 con- secutive patients （81 men and 64 women; mean age 65.5 ± 8.0 years） with persistent non-valvular AF and normal left ventricular systolic function （left ventdcular ejection fraction 〉 50%）. All patients underwent a symptom-limited cardiopulmonary exercise test （CPET）. Doppler echocardiography was performed both at rest and immediately after exercise. Five consecutive measurements of early diastolic mitral inflow velocity （E） and early diastolic mitral annular velocity （e＇） were taken and averaged. E/e＇ ratio was calculated. Elevated LVFP was defined as E/e＇ 〉 9, and patients with elevated LVFP at rest were excluded. Results Patients were classified into two groups according to LVFP estimated by E/e＇ ratio after exercise： 39 （26.9%） with elevated LVFP after exercise and 106 （73.1%） with normal LVFP. As compared with patients with normal LVFP, the ones with elevated LVFP after exercise had significantly lower peak oxygen uptake （VO2 peak） （21.7 ± 2.3 vs. 26.4 ± 3.8 mL/min per kilogram, P 〈 0.001）, lower anaerobic threshold （19.9 ± 2.5 vs. 26.0± 4.0 mL/min per kilogram, P 〈 0.001）, and shorter exercise time duration （6.2± 0.8 vs. 7.0 ±1.3 min, P 〈 0.001）. Multivariate analysis showed that age, gender and E/e＇ after exercise were significantly correlated with VO2peak. Conclusion Elevated LVFP estimated by E/e＇ ratio after exercise is independently associated with reduced exercise capacity in AF patients.

Is there a role for ischemia detection after an acute myocardial infarction?

Coronary angiography and eventual revascularization have become the most common approaches for patients with acute coronary syndromes.Ischemia detection in this scenario is usually regarded as unnecessary for most of the patients.In fact,current guidelines recommend complete revascularization for patients with multivessel disease in the context of ST-elevation myocardial infarction,although it is in contrast with previous recommendations.However,some recent data suggested that ischemia could have a role for the decision of revascularization in these patients.The CROSS-AMI study randomized patients with ST-elevation myocardial infarction treated with primary angioplasty and who also had multivessel disease to a complete anatomic revascularization of the non-infarct related artery lesions vs subsequent revascularization of the noninfarct related artery lesions only if ischemia was demonstrated by stress echocardiography.The main findings were that only 30%of the patients in the ischemia arm needed a second revascularization and that the outcome was similar in both arms.Regarding non-ST-elevation acute coronary syndrome,coronary angiography is in general warranted for most of the patients.However,recent long-term published studies on patients randomized to an invasive or less aggressive approach based on ischemia detection have found no differences in outcome.The ultimate study in non-ST-elevation acute coronary syndrome comparing ischemia detection with an invasive approach is pending.Therefore,ischemia detection might have a role for stratifying these subjects.This is particularly true in the current era of imaging of high quality and sensitivity,last generation stents,radial access and modern antithrombotic therapy.

Viable Myocardium Impact on Left Ventricular Function after Late Revascularization of Infarct-related Artery in Acute Myocardial Infarction

Objectives The long-term benefit of late reperfusion of infarct-related artery （IRA） after acute myocardial infarction （AMI） is controversial, and the benefit mechanisms remain uncertain. Low dose dobutamine stress echocardiography （LDSE） can identify viable myocardium and predict improvement of wall motion after revascularization. Methods Sixtynine patients with first AMI who did not received early reperfusion therapy were studied by LDSE at 5 to 10 days after AMI. Wall motion abnormality and left ventricular size were measured at the same time. Successful PCI were done in all patients at 10 to 21 days after AMI onset. Patients were divided in two groups based on the presence or absence of viable myocardium. Echocardiography was repeated six months later. Results There were 157 motion abnormality segments. 89 segments （57%） were viable during LDSE. 26 patients （38%） with viability and 43 （62%） without. In viable group, left ventricular ejection fraction （LVEF） was increased （P 〈 0.05）, and left ventricular end systolic volume index （LVESVI） and wall motion score （WMS） were decreased （P 〈 0.05 and P 〈 0.01） significantly at 6 months compared with baseline. But in patients without viability, LVEF was decreased （P 〈 0.01）, and LVESVI and left ventricular end diastolic volume index （LVEDVI） were increased （P 〈 0.05） significantly after 6 months, and the WMS did not changed （P 〉 0.05 ）. LVEF increased （P 〈 0.05 ） and WMS decreased （P 〈 0.05） on LDSE during acute phase in patients with viability, but they were not changed in the nonviable group. Conclusions Late revascularization of IRA in patients with presence of viable myocardium after AMI is associated with long-term preservation left ventricular function and less ventricular remodeling. Improvement of left ventricular systolic function on LDSE indicates late phase recovery of left ventricular function after late revascularization.