Long-Term Prediction of Mortality in Elderly Persons by Dobutamine Stress Echocardiography

Simple six-item clinical score improves risk prediction capability of stress echocardiography

Objectives

To assess the value of a simple score integrating non-ischaemia-related variables in expanding the wall motion abnormalities risk power during stress echocardiography (SE).

Methods

Study includes 14 279 patients who underwent SE for evaluation of coronary artery disease. All-cause death was the end point. Patients were randomly divided into the modelling and validation group of equal size. In the modelling group, multivariate analysis was conducted using clinical, rest and SE data, and a score was obtained from the number of non-ischaemia-related independent prognostic predictors. The score prognostic capability was compared in both groups.

Results

During a median follow-up of 31 months, 1230 patients died: 622 (9%) in the modelling and 608 (9%) in the validation group (p=0.68). Independent predictors of mortality were ischaemia at SE (HR 1.77, 95% CI 1.49 to 2.12; p<0.0001) and six other parameters: age>65 years, wall motion at rest, diabetes, left bundle branch block, anti-ischaemic therapy and male sex. Risk score resulted prognostically effective in the modelling and validation groups, both with and without inducible ischaemia subset. When risk score was included in the multivariate analysis, besides ischaemia at SE it was the only independent predictor of mortality in the modelling (HR 1.70, 95% CI 1.60 to 1.82; p<0.0001), in the validation (HR 1.77, 95% CI 1.65 to 1.90; p<0.0001) and in the overall group (HR 1.73, 95% CI 1.66 to 1.82; p<0.0001).

Conclusions

Simple clinical variables may be able to optimise SE risk stratification.

Prognostic usefulness of contemporary stress echocardiography in patients with left bundle branch block and impact of contrast use in improving prediction of outcome

Aims

Patients with symptomatic left bundle branch block (LBBB) may have myocardial ischaemia due to both coronary artery disease and/or cardiomyopathy (microcirculatory abnormalities) and may have concomitant left ventricular (LV) dysfunction. We aimed to assess the feasibility and prognostic value of contemporary stress echocardiography (SE), which can uncover both pathophysiologies in LBBB patients in routine clinical practice, and also aimed to assess the additive value of contrast SE.

Methods and results

Accordingly, 190 consecutive patients (age 70.5 ± 11.3 years, LV ejection fraction = 50.1 ± 10%) with symptomatic LBBB who underwent SE over 6 years were assessed, of which 142 (75%) underwent contrast SE and 176 (92.6%) had diagnostic SE. Inducible ischaemia was present in 25 (14.2%) patients. During follow-up (35.4 ± 20.2 months) there were 32 deaths (18%) and 18 (10.2%) first cardiovascular (CV) events (acute myocardial infarction/mortality) in the 176 patients with diagnostic studies. Wall thickening score index at peak stress (WTSIpeak), which measures combined LV function and inducible ischaemia, was an independent predictor of mortality (HR = 3.78, 95% CI = 1.39-10.31, P = 0.01) and CV events (HR = 3.96, 95% CI = 1.1-14.3, P = 0.036). An abnormal SE (myocardial ischaemia and/or abnormal LV function) predicted an almost three-fold increase in all-cause mortality and CV events compared with normal SE. Amongst the confounders affecting assessment of wall thickening in LBBB and conventional prognostic variables, use of contrast was an independent predictor (P = 0.034) of WTSI1.16 (optimal predictor of mortality/CV outcome).

Conclusion

SE in patients with LBBB demonstrated high feasibility and the combination of LV systolic function and myocardial ischaemia provided important prognostic information. Contrast-enhanced SE improved the prediction of outcome.

Predictors and prognostic significance of atrial fibrillation developed during dobutamine stress echocardiography: A propensity score-matched comparison

AIMS

Atrial fibrillation (AF) uncommonly occurs during dobutamine stress echocardiography (DSE). We aimed to characterize the predictors and long-term prognostic significance of AF during DSE.

METHODS

The clinical, echocardiographic, and outcome data of patients in sinus rhythm who developed AF during DSE were reviewed and compared to a propensity score-matched group of controls.

RESULTS

Atrial fibrillation developed in 73 (1% of 7026) patients (age 70±10 years, 58% men). Compared to 144 propensity score-matched controls without AF during DSE, those with AF were more likely to have had history of prior AF (23% vs 8%, P=.002), known coronary artery disease (CAD; 22% vs 10%, P=.037), enlarged left ventricle (LV; 27% vs 9%, P=.002), LV wall-motion abnormality (33% vs 12%, P<.0001), enlarged aortic root (22% vs 8%, P=.009), or dilated left atrium (52% vs 30%, P=.002). Multivariate logistic regression analysis identified prior history of AF (OR=3.7, 95% CI 1.5-9.0, P=.005), larger LV size (OR=3.1, 95% CI 1.3-7.3, P=.009), and lower LV ejection fraction (OR=-0.95, 95% CI -0.92 to -0.99, P=.02) as independent predictors of AF during DSE. At a mean follow-up period of 3.4 (0.5-7.3) years, those with AF during DSE were more likely to develop new coronary events (22% vs 10%, P=.0372), new-onset heart failure (19% vs 4%, P=.0003), or die from any cause (27% vs 6%, P<.0001). Kaplan-Meier curves demonstrated significantly lower event-free survival in patients compared to controls (P by log-rank test=.001) over the follow-up period.

CONCLUSION

Dobutamine-induced AF occurs more commonly in those with prior history of AF and remodeled LV and is associated with unfavorable outcomes.

Long-Term (>10 Years) Prognostic Value of Dobutamine Stress Echocardiography in a High-Risk Cohort

The prognostic value of dobutamine stress echocardiography (DSE) at >10-year follow-up is unknown. The aim of this study was to assess the very long-term prognostic value of DSE in a high-risk cohort of patients with known or suspected coronary artery disease. This prospective, single-center study included 3,381 patients who underwent DSE from January 1990 to January 2003. Two-dimensional echocardiographic images were acquired at rest, during dobutamine stress, and during recovery. Follow-up events were collected and included overall mortality, cardiac death, nonfatal myocardial infarction, and revascularization. The incremental value of DSE in the prediction of selected end points was evaluated using multivariate Cox proportional hazard analysis. During a mean follow-up of 13 ± 3.2 years (range 7.3 to 20.5 years), there were 1,725 deaths (51%), of which 1,128 (33%) were attributed to cardiac causes. Patients with an abnormal DSE had a higher mortality rate (44% vs 35% at 15-year follow-up, p <0.001) than those with a normal DSE. When comparing echocardiographic variables at rest to variables at maximum dose dobutamine, the chi-square of the test improved from 842 to 870 (p <0.0001) and from 684 to 740 (p <0.0001) for all-cause mortality and cardiac death, respectively. DSE provided incremental value in predicting all-cause mortality, cardiac death, and hard cardiac events. There seems, however, to be a "warranty period" of approximately 7 years, when the survival curves of a normal and abnormal DSE no longer diverge.

The prognostic value of dobutamine stress echocardiography amongst British Indian Asian and Afro-Caribbean patients: a comparison with European white patients

Background

The incidence of cardiovascular disease is considerably disparate among different racial and ethnic populations. While dobutamine stress echocardiography (DSE) has been shown to be useful in Caucasian patients, its role among ethnic minority groups remains unclear. This study aimed to investigate the prognostic importance of DSE in three ethnic groups in the UK.

Methods

DSE was performed on 6231 consecutive patients. After exclusions, 5329 patients formed the study (2676 [50.2 %] Indian Asian, 2219 [41.6 %] European white and 434 [8.1 %] Afro-Caribbean). Study outcome measures were non-fatal cardiac events (NFCE) and all-cause mortality.

Results

There were 849 (15.9 %) NFCE and 1365 (25.6 %) deaths over a median follow-up period of 4.6 years. In total 1174 (22 %) patients had inducible myocardial ischaemia during DSE, 859 (16.1 %) had fixed wall motion abnormalities and 3645 (68.4 %) patients had a normal study. Ethnicity did not predict events. Among the three ethnic groups, ischaemia on DSE was associated with 2 to 2.5 times the risk of non-fatal cardiac events and 1.2 to 1.4 times the risk of all-cause mortality. Peak wall motion score index was the strongest independent predictor of non-fatal cardiac events and all-cause mortality in all groups. The C statistic for the prediction of NFCE and all-cause mortality were significantly higher when DSE parameters were added to the standard risk factors for all ethnic groups.

Conclusions

DSE is a strong predictor of NFCE and all-cause mortality and provides predictive information beyond that provided by standard risk factors in three major racial and ethnic groups. No major differences among racial and ethnic groups in the predictive value of DSE was detected.

Electronic supplementary material

The online version of this article (doi:10.1186/s12947-015-0028-1) contains supplementary material, which is available to authorized users.

Prognostic value of Doppler echocardiographic-derived coronary flow velocity reserve of left anterior descending artery in octogenarians with stress echocardiography negative for wall motion criteria

AIMS

Doppler-derived coronary flow velocity reserve (CFVR) of left anterior descending (LAD) artery is an effective tool to predict overall mortality. The aim was to investigate the capability of CFVR to predict outcome in an unselected cohort of patients older than 80 years having stress echo negative by wall motion criteria.

METHODS AND RESULTS

The study group refers to 369 patients aged > 80 years (156 men; mean age 83 ± 2 years) who had undergone dipyridamole stress echocardiography with CFVR assessment of LAD artery of known (n = 144) or suspected (n = 225) coronary artery disease. Stress echocardiography was negative for wall motion criteria in all cases. Mean CFVR was 2.07 ± 0.53. During a median follow-up of 21 months, there were 62 major adverse cardiac events (MACEs; 45 deaths and 17 non-fatal myocardial infarctions). With a receiver operating characteristic analysis, a CFVR of ≤ 1.93 was the best cut-off for predicting mortality and MACE. At individual patient analysis, 152 (41%) subjects had a CFVR of < 1.93. Annual mortality was 9.8% in patients with CFVR <1.93 and 3.7% in those with CFVR > 1.93 (P = 0.001); an annual MACE rate was 14.8% in the former and 4.5% in the latter (P < 0.0001). Of 15 clinical and echocardiographic parameters analysed, CFVR ≤ 1.93 [hazard ratio (HR) = 2.17, 95% CI 1.14-4.10] and resting wall motion abnormality (RWMA; HR = 2.60; 95% CI 1.35-5.00) were multivariable indicators of mortality. Moreover, CFVR ≤ 1.93 (HR = 2.69, 95% CI 1.56-4.67), and RWMA (HR = 2.38; 95% CI 1.31-4.33) were also strong independent predictors of MACEs. At incremental analysis, CFR ≤ 1.93 added prognostic information over clinical evaluation and RWMA when both mortality and MACE were taken as clinical end points.

CONCLUSIONS

A reduced CFVR of LAD artery is a strong and independent indicator of both mortality and MACE, adding prognostic information over clinical evaluation and RWMA. Conversely, a preserved CFVR predicts a favourable outcome particularly in subjects with no RWMA.

Meta-analysis of optimal risk stratification in patients >65 years of age

This meta-analysis evaluated the optimal noninvasive strategy for cardiac risk assessment of patients >65 years of age with known or suspected coronary artery disease using the available literature. Patients >65 years of age constitute a growing proportion of the population and have higher cardiovascular morbidity and mortality, but an optimal strategy to predict the risk of cardiac events in this group is unknown. A systematic search of MEDLINE was performed for cohort studies of ≥100 patients >65 years old with ≥12 months of follow-up that reported cardiac death and/or nonfatal myocardial infarction after any of stress myocardial perfusion imaging (MPI), stress echocardiography, or exercise tolerance testing (ETT) for known or suspected coronary artery disease. Pooled annualized event rates were calculated for each technique. Summary odds ratios (ORs) between normal and abnormal test results were calculated using a random-effects model. Seventeen studies (MPI 7, stress echocardiography 7, ETT 3) in 13,304 patients (mean age 75.5 years) were included. Abnormal compared to normal stress MPI (OR 11.8, 95% confidence interval [CI] 7.5 to 18.7) and stress echocardiography (OR 3.2, 95% CI 2.6 to 3.9) accurately stratified risk in patients. However, patients with abnormal and normal ETT results had similar cardiac event rates (OR 3.1, 95% CI 0.8 to 11.5). In conclusion, stress imaging with MPI or stress echocardiography effectively stratified risk in patients, whereas ETT alone did not.

Left ventricular cavity obliteration during dobutamine stress echocardiography in diabetic patients

Prevalence of dynamic left ventricular outflow tract obstruction (DLVO) during dobutamine stress-echo (DSE) seems disproportionally high among diabetic patients. We retrospectively identified 212 diabetic (D+) and 212 non diabetic (D-) subjects, who underwent DSE for suspected coronary artery disease (CAD); we evaluated DSE-induced DLVO prevalence and correlates. During DSE, 105 patients in D+ (50%) and 83 in D- group (39%, P = 0.032) developed a DLVO, with similar maximum gradient (94 ± 49 mmHg in D+ vs. 86 ± 49 mmHg in D-, P = NS). D+ and D- patients with DLVO showed reduced LV end-diastolic and end-systolic dimension. Compared with diabetic subjects without DLVO, diabetic patients with DLVO had higher left ventricular (LV) ejection fraction (EF), lower LV mass index; diastolic function was normal in a higher proportion of cases. Non diabetic patients with moderate or severe DLVO had higher LV EF compared with patients without DLVO. At multivariate analysis, in D+ patients, the only independent predictor was a smaller LV end-diastolic diameter (HR 0.779, CI 0.655-0.926, P = 0.005); in D- patients lower age (HR 0.878, CI 0.806-0.957, P = 0.003), higher LV EF (HR 1.087, CI 1.003-1.177, P = 0.042) and lower peak WMSI (HR 0.017, CI 0.001-0.325, P = 0.007) were associated to presence of DLVO. In D+ patients, during a median follow-up of 924 ± 134 days, we observed 11 new cardiac events, only 1 in patients with DLVO (P = 0.0041). DSE-provoked DLVO had a very high prevalence in patients evaluated for suspected CAD, especially among diabetic patients; echocardiographic predictors were a reduced LV dimension in D+ and a preserved systolic function, both at rest and at peak stress, in D- patients.

Does the prognostic value of dobutamine stress echocardiography differ among different age groups?

BACKGROUND

Age is associated with reduced exercise capacity and greater prevalence of coronary artery disease. Whether the prognostic information obtained from dobutamine stress echocardiography (DSE), a stress test commonly used for patients unable to perform an exercise test, provides differential information based on age is not well known.

METHODS

We studied 6,655 consecutive patients referred for DSE. Patients were divided into 3 age groups: (1) <60 years (n = 1,389), (2) 60 to 74 years (n = 2,978), and (3) ≥75 years (n = 2,288). Mean follow-up was 5.5 ± 2.8 years. End points included all-cause mortality and cardiac events, including myocardial infarction and late (>3 months) coronary revascularization.

RESULTS

Peak stress wall motion score index was an independent predictor of cardiac events in all age groups (<60 years: hazard ratio [HR] 1.14, P = .02; 60-74 years: HR 1.70, P < .0001; ≥75 years: HR 1.10, P = .006). In patients ≥75 years, peak wall motion score index (HR 1.10, P < .0001) and abnormal left ventricular end-systolic volume response (HR 1.25, P = .03) were independent predictors of death. In patients aged 60 to 74 years, abnormal left ventricular end-systolic volume response (HR 1.43, P = .0003) was independently related to death, whereas in patients <60 years, the echocardiographic data assessed during stress were not a predictor.

CONCLUSIONS

Dobutamine stress echocardiography provided independent information predictive of cardiac events among all age groups and death in patients ≥60 years. However, among patients <60 years, stress-induced echocardiographic abnormalities were not independently associated with mortality. Comorbidities, which have precluded exercise testing, may be most relevant in predicting mortality in patients <60 years undergoing DSE.

Value of exercise echocardiography for predicting mortality in elderly patients

BACKGROUND

Elderly patients with suspected or known coronary artery disease are often referred for pharmacological stress testing. Data on the value of exercise echocardiography (ExEcho) for predicting outcome (particularly all-cause mortality) in these patients are scarce.

METHODS

Peak treadmill ExEcho was performed in 2159 patients ≥ 70 years of age with known or suspected coronary artery disease. Left ventricular wall motion was evaluated at baseline and with exercise, and the increase in wall motion score index from rest to peak exercise (ΔWMSI) was calculated. Ischaemia was diagnosed when new or worsening wall motion abnormalities developed with exercise. The end points were all-cause mortality and major cardiac events (cardiac death or myocardial infarction).

RESULTS

Ischaemia developed in 844 patients (38·6%) during exercise. Over a mean follow-up of 3·5 ± 3·1 years, 439 deaths occurred. The cumulative 5-year mortality rate was 29·3% in patients with ischaemia versus 16·8% in those without ischaemia (P < 0·001). After covariate adjustment, ΔWMSI remained an independent predictor of mortality [hazard ratio (HR) 2·37, 95% confidence interval (CI) 1·66-3·39, P < 0·001] and major cardiac events (HR 3·48, 95% CI 2·11-5·74, P < 0·001). These results remained significant even in patients with chronotropic incompetence. When added to a model with clinical, resting echocardiographic and exercise electrocardiogram variables, ExEcho results provided incremental value for the prediction of both end points (P < 0·001).

CONCLUSIONS

ExEcho is feasible in elderly patients with suspected or known coronary artery disease and provides useful information for risk stratification in these patients.

Native cardiac reserve predicts survival in acute post infarction heart failure in mice

Cardiac reserve can be used to predict survival and outcome in patients with heart failure. The aim of this study was to investigate if native cardiac reserve could predict survival after myocardial infarction (MI) in mice.

METHOD

We investigated 27 healthy C57Bl6 mice (male symbol10-12 weeks old) with echocardiography using a high-frequency 15-MHz linear transducer. Investigations were performed both at rest and after pharmacological stress induced by dobutamine (1 mug/g body weight i.p.). The day after the echocardiography examination, a large MI was induced by ligation of the left anterior descending (LAD) coronary artery for evaluation of mortality rate.

RESULTS

Two weeks after induction of MI, 7 mice were alive (26%). Evaluation of the difference between the surviving and deceased animals showed that the survivors had a better native ability to increase systolic performance (DeltaLVESd -1.86 vs -1.28mm p = 0.02) upon dobutamine challenge, resulting in a better cardiac reserve (DeltaFS 37 vs 25% p = 0.02 and DeltaCO 0.27 vs -0.10 ml/min p = 0.02) and a better chronotropic reserve (DeltaR-R interval -68 vs -19 ms p < 0.01). A positive relationship was found between ability to survive and both cardiac (p < 0.05) and chronotropic reserve (p < 0.05) when the mice were divided into three groups: survivors, surviving < 7 days, and surviving < 1 day.

CONCLUSION

We conclude that before MI induction the surviving animals had a better cardiac function compared with the deceased. This indicates that native cardiac and chronotropic reserve may be an important determinant and predictor of survival in the setting of large MI and post-infarction heart failure.

The long prognostic value of wall motion abnormalities during the recovery phase of dobutamine stress echocardiography after receiving acute beta-blockade

OBJECTIVE

To assess the prognostic value of wall motion abnormalities during the recovery phase of dobutamine stress echocardiography in addition to wall motion abnormalities at peak stress.

METHODS

Wall motion abnormalities were assessed at peak and during recovery phase of dobutamine stress echocardiography in 187 consecutive patients, who were followed for occurrence of cardiac events.

RESULTS

During follow-up (mean 36+/-28 months), 19 patients (10%) died from cardiac causes, 34 (18%) patients suffered nonfatal myocardial infarction, and 77 (41%) patients underwent late revascularization. Univariable predictors of cardiac events by Cox regression analysis were age (hazard ratio: 1.01; confidence interval: 1.00-1.03), dyslipidemia (hazard ratio: 1.41; confidence interval: 1.02-1.95), rest wall motion abnormalities (hazard ratio: 1.37; confidence interval: 1.14-1.64), new wall motion abnormalities (hazard ratio: 1.18; confidence interval: 0.95-1.45) at peak and new wall motion abnormalities (hazard ratio: 1.33; confidence interval: 1.11-1.59) at recovery phase of dobutamine stress echocardiography. The best multivariable model to predict cardiac events included new wall motion abnormality (hazard ratio: 5.34; confidence interval: 1.71-16.59) at recovery phase of dobutamine stress echocardiography, after controlling for clinical and peak dobutamine stress echocardiography data.

CONCLUSIONS

Myocardial ischemia at recovery phase of dobutamine stress echocardiography is an independent predictor of cardiac events and has an incremental value when added to ischemia at peak.

Prognostic implications of dipyridamole or dobutamine stress echocardiography for evaluation of patients > or =65 years of age with known or suspected coronary heart disease

This study investigated the value of pharmacologic stress echocardiography for risk stratification of patients > or =65 years of age. The study cohort consisted of 2,160 patients > or =65 years of age (1,257 men, mean +/- SD 71 +/- 5 years of age) undergoing dipyridamole (n = 1,521) or dobutamine (n = 639) stress echocardiography for evaluation of known (n = 913) or suspected (n = 1,247) coronary artery disease. Of 2,160 patients, 753 (35%) had a normal test result, whereas 772 (36%) showed a myocardial ischemic pattern and 635 (29%) a scar pattern. During a median follow-up of 26 months, 241 deaths and 87 nonfatal myocardial infarctions occurred. Patients (n = 568) undergoing revascularization were censored. Of 16 analyzed variables, age (hazard ratio [HR] 1.07 per unit increment), wall motion score index at rest (HR 2.63 per unit increment), ischemia at stress echocardiography (HR 1.81), and diabetes (HR 1.57) were multivariable predictors of death, whereas age (HR 1.06 per unit increment), ischemia at stress echocardiography (HR 2.60), wall motion score index at rest (HR 1.98 per unit increment), scar pattern (HR 1.99), and diabetes (HR 1.48) were multivariable predictors of death or myocardial infarction. Using an interactive stepwise procedure, stress echocardiography showed incremental prognostic value over clinical and echocardiographic data at rest, which decreased with increasing age. In addition, the annual hard event rate associated with a normal test result progressively increased with age. In conclusion, pharmacologic stress echocardiography provides useful prognostic information in patients > or =65 years of age. However, its prognostic value decreases with increasing age.