Safety and feasibility of dopamine-atropine stress echocardiography.

BACKGROUND: Dobutamine-atropine stress echocardiography (DSE) has lower sensitivity in patients with advanced liver disease (ALD) due to vasodilation. HYPOTHESIS: Dopamine-atropine stress echocardiography (DopSE) may be an alternative to DSE in ALD patients by improving the blood pressure response to stress. METHODS: The safety and tolerability of DSE and DopSE were compared in 10 volunteers. The safety, adverse effects, and efficacy of DopSE were then assessed in 105 patients, 98 of whom had ALD. Dopamine was infused in stepwise fashion from 5 µg/kg/min to a peak dose of 40 µg/kg/min. Atropine was given before and in early stages of dopamine infusion up to cumulative dose of 1.5 mg. The hemodynamic responses of 98 ALD patients were compared with 102 patients with ALD who underwent standard DSE. RESULTS: In normal volunteers, systolic BP increased more with DopSE compared to DSE (61 ± 19 mm Hg vs 39 ± 15 mm Hg, P = .008). In 105 patients who underwent DopSE, none had adverse effects that required early stress termination. In the groups with ALD, the systolic BP increase (38 ± 28 mm Hg vs 12 ± 27 mm Hg, P < .001) and peak rate pressure product (RPP) (22 861 ± 5289 vs 17 211 ± 3848, P = <.001) were both higher in those undergoing DopSE versus DSE. The sensitivity and specificity of DopSE were 45% and 88%, respectively for coronary disease (≥70% stenosis) in 37 patients who had angiography. CONCLUSIONS: Dopamine-atropine stress echocardiography appears to be a safe stress modality and provides greater increases in RPP in patients with ALD compared to DSE.

Improving prediction of outcomes in African Americans with normal stress echocardiograms using a risk scoring system.

Cardiovascular mortality is high in African Americans, and those with normal results on stress echocardiography remain at increased risk. The aim of this study was to develop a risk scoring system to improve the prediction of cardiovascular events in African Americans with normal results on stress echocardiography. Clinical data and rest echocardiographic measurements were obtained in 548 consecutive African Americans with normal results on rest and stress echocardiography and ejection fractions ≥50%. Patients were followed for myocardial infarction and death for 3 years. Predictors of cardiovascular events were determined with Cox regression, and hazard ratios were used to determine the number of points in the risk score attributed to each independent predictor. During follow-up of 3 years, 47 patients (8.6%) had events. Five variables-age (≥45 years in men, ≥55 years in women), history of coronary disease, history of smoking, left ventricular hypertrophy, and exercise intolerance (<7 METs in men, <5 METs in women, or need for dobutamine stress)-were independent predictors of events. A risk score was derived for each patient (ranging from 0 to 8 risk points). The area under the curve for the risk score was 0.82 with the optimum cut-off risk score of 6. Among patients with risk scores ≥6, 30% had events, compared with 3% with risk score <6 (p <0.001). In conclusion, African Americans with normal results on stress echocardiography remain at significant risk for cardiovascular events. A risk score can be derived from clinical and echocardiographic variables, which can accurately distinguish high- and low-risk patients.

Learning to interpret the extracardiac findings on coronary CT angiography examinations.

Coronary computed tomography angiography (CTA) plays an important role in the identification of coronary artery disease in low- to intermediate-risk patients. Even with a "restrictive" field of view, coronary CTA data sets will include visualization of structures adjacent to the heart, including the thoracic great vessels, pericardium, mediastinum, lungs, and bones. CT images enable detailed assessment of these structures, at times identifying a potential noncoronary cause of the patient's presenting symptom. The reported incidence of extracardiac findings on coronary CTA is as high as 53%-67%. Complete evaluation of the examination requires scrutiny of the soft tissues, lung tissues, and bones, both in the chest and adjacent abdomen. It is important to adjust the CT window display settings at various stages of the interpretation process to evaluate all potential extracardiac disease. Although in-depth radiology training would be required to correctly identify and interpret all anomalies, this article serves as an overview and guide to evaluation of the extracardiac structures included on a coronary CTA examination. Correct interpretation of extracardiac findings is critical because a false positive interpretation can lead to unnecessary testing and treatment that can be as harmful as a false negative interpretation. Most importantly, if the cardiac findings do not explain the patient's symptoms, an alternative cause should be specifically sought to appropriately manage the patient.

Incremental prognostic value of echocardiography in patients with prior mitral valve surgery.

BACKGROUND AND AIM OF THE STUDY: Patients with prior mitral valve surgery are at increased risk for events late after surgery. The study aim was to investigate the value of assessing clinical variables, and left and right heart anatomy and function, to predict outcome in these patients. METHODS: Two-dimensional echocardiography, Doppler echocardiography and tissue Doppler imaging (TDI) were performed in 84 patients at a mean of 7.3 +/- 7.1 years after mitral valve surgery. The left ventricular ejection fraction (LVEF) was 50 +/- 15%, and 30% of patients were in NYHA class III/IV (congestive heart failure; CHF). Follow up was obtained for events that included repeat mitral or tricuspid valve surgery, and death. RESULTS: During a follow up period of 4.3 +/- 2.0 years, 28 patients suffered events, the univariate clinical predictors of which were NYHA class, calcium antagonist therapy, hyperlipidemia, and tobacco smoking. Left heart predictors included the mean mitral valve gradient (MMVG), left atrial volume index, and lateral wall TDI systolic velocity. Right heart predictors were atrial and right ventricular (RV) dimensions, RV systolic pressure, tricuspid regurgitation (TR) severity, RV free wall TDI E-velocity and E/e' ratio. Multivariate analysis showed that NYHA class (p = 0.02; RR 1.8 (1.1-2.9)), MMVG (p < 0.001; RR 1.16 (1.08-1.24)) and RV dimensions (p = 0.001; RR = 3.2 (1.7-6.2)) were independent predictors of events. A step-wise analysis of independent predictors showed that MMVG added an incremental value to NYHA class (p = 0.003), while RV size added additional value (p = 0.007) to the combination of NYHA class and MMVG. CONCLUSION: Echocardiographic assessments of the left and right heart can add significant prognostic value to the clinical assessment of patients after mitral valve surgery.

Effect of improvement in left ventricular ejection fraction on long-term survival in revascularized patients with ischaemic left ventricular systolic dysfunction.

AIMS: The importance of improvement in the ejection fraction to the prognosis of revascularized patients with ischaemic left ventricular (LV) dysfunction is uncertain. METHODS AND RESULTS: Eighty-seven patients with ischaemic LV dysfunction (mean ejection fraction 29 ± 8% by biplane Simpson's) had dobutamine echocardiography before revascularization (coronary bypass graft surgery-81, percutaneous intervention-6). Follow-up echocardiograms were performed a mean of 4.8 ± 6.2 months after revascularization. An 8% increase in the ejection fraction was considered significant (two times the inter-observer difference of 3.7%). Patients were followed for cardiac death. During a mean follow-up of 5.2 ± 3.9 years, there were 20 (23%) cardiac deaths. Class 3/4 heart failure, increasing low-dose wall motion score, increasing % non-viable myocardium, and digoxin use in follow-up were univariate predictors of death. Beta-blocker use, ejection fraction improvement, angina, aspirin use, and increasing fractional shortening were univariate predictors of survival. Ejection fraction improvement [P= 0.02, hazard ratio (HR) = 0.26], digoxin use in follow-up (P= 0.006, HR = 5.85), and low-dose wall motion score (P= 0.017, HR = 4.78) were independent predictors of outcome. In step-wise analysis, low-dose wall motion score added incremental prognostic value to ejection fraction improvement (P= 0.003), and digoxin use in follow-up (P= 0.003) added incremental value to a low-dose score and ejection fraction improvement. CONCLUSION: Ejection fraction improvement is an independent predictor of long-term outcome in revascularized patients but viability (low-dose wall motion score) and digoxin use in follow-up are also independent predictors and add incremental prognostic value to ejection fraction improvement.

Effect of revascularization on long-term survival in patients with ischemic left ventricular dysfunction and a wide range of viability.

Short-term survival in patients with viability and ischemic left ventricular dysfunction appears improved by revascularization, but no randomized studies have shown a long-term benefit of revascularization in patients with a wide range of viability. Propensity analysis was used as a substitute for randomization in a study comparing the survival of revascularized and medically treated patients with ischemic dysfunction. Dobutamine echocardiography was performed in 274 patients with ischemic left ventricular dysfunction (mean ejection fraction 32%), with 32% having viability in > or =25% of the myocardium. Clinical, angiographic, and echocardiographic characteristics were comparable between treatment groups except for multivessel disease, hyperlipidemia, and the percentage of nonviable myocardium. A propensity score, reflecting the probability of receiving revascularization, was derived for each patient from baseline variables. After stratification by propensity scores, there were no differences between groups. Patients were followed for cardiac death. Revascularization was performed in 130 patients, and 144 were medically treated. There were 114 cardiac deaths (42%) over 4.5 years of follow-up. After propensity score adjustment, survival was better with revascularization (mean survival 5.9 vs 3.3 years, hazard ratio 0.42, 95% confidence interval 027 to 0.65, p <0.0001). Medical and device therapy during follow-up was similar between treatment groups, except that beta-blocker use was more common in revascularized patients. After adjustment for beta-blocker use and propensity score, survival remained better in revascularized patients (hazard ratio 0.47, 95% confidence interval 0.30 to 0.72, p = 0.0006). In conclusion, revascularization improves long-term survival in patients with ischemic left ventricular dysfunction and a wide range of viability.

Wall motion abnormalities with low-dose dobutamine predict a high risk of cardiac death in medically treated patients with ischemic cardiomyopathy.

BACKGROUND: Severe and extensive coronary artery disease is the underlying cause of stress-induced wall motion abnormalities (SWMA) with low-dose (10 microg/kg/min) dobutamine suggesting that these abnormalities may identify those with poor outcome. HYPOTHESIS: We assessed the prognostic value of low-dose SWMA in medically treated patients with ischemic cardiomyopathy. METHODS: Low- and peak-dose dobutamine echocardiography was performed in 235 patients with ischemic cardiomyopathy (ejection fraction 31% +/- 8%) who were treated with medical therapy. The survival of patients with low-dose SWMA (n = 33) was compared with the survival of patients without ischemia (n = 85) and those with peak-dose SWMA (n = 117). RESULTS: There were 123 cardiac deaths (52%) during follow-up of 4.1 +/- 3.3 years. Multivariate predictors of cardiac death were age (p = 0.002, hazard ratio [HR]: 1.03), diabetes (p = 0.028, HR: 1.54), New York Heart Association (NYHA) class III, IV heart failure (p = 0.001, HR: 1.94), the presence of peak dose SWMA (p < 0.001, HR: 2.59), and low-dose SWMA (p = 0.005, HR: 2.28). Survival of patients without ischemia was significantly better than those with peak-dose SWMA (p < 0.0001) and those with low-dose SWMA (p = 0.001). The survival of patients with low-dose SWMA was the same as those with peak-dose SWMA (p = 0.89). CONCLUSIONS: Low-dose SWMA is an independent predictor of cardiac mortality in medically treated patients with ischemic cardiomyopathy. Patients with low-dose SWMA are at equivalent risk to those with peak-dose SWMA.

Clinical assessment and rest and stress echocardiography for prediction of long-term prognosis in African Americans with known or suspected coronary artery disease.

BACKGROUND: There is limited information on noninvasive risk stratification of African Americans, a high-risk group for cardiovascular events. We investigated the value of clinical assessment and echocardiography for the prediction of a long-term prognosis in African Americans. METHODS: Dobutamine echocardiography was performed in 324 African Americans. Two-dimensional measurements were performed at rest, and rest and stress wall motion was assessed. A retrospective follow-up was conducted for cardiac events: myocardial infarction (MI) or cardiac death (CD). RESULTS: The mean age was 59 +/- 12 years, and 83% of patients had hypertension. The follow-up was obtained in 318 (98%) patients for a mean of 5.3 years. The events occurred in 107 (33%) subjects. The independent predictors of events were history of MI (P = 0.001, risk ratio [RR] 2.04), ischemia (P = 0.007, RR 1.97), fractional shortening (P = 0.033, RR 0.08), and left atrial (LA) dimension (P = 0.034, RR 1.39). An LA size of 3.6 cm and a fractional shortening of 0.30 were the best cutoff values for the prediction of events. Prior MI, ischemia, LA size >3.6 cm, and fractional shortening <0.30 were each considered independent risk predictors for events. The event rates were 13%, 21%, 38%, 59%, and 57% in patients with 0, 1, 2, 3, and 4 risk predictors, respectively. Event-free survival progressively worsened with an increasing number of predictors: 0 or 1 versus 2 predictors, P < 0.001; 2 versus 3 or 4 predictors, P = 0.003. CONCLUSION: The long-term prognosis of African Americans can be accurately predicted by clinical assessment combined with rest and stress echocardiography.

Persistent left ventricular dilatation in tachycardia-induced cardiomyopathy patients after appropriate treatment and normalization of ejection fraction.

BACKGROUND: Tachycardia-induced cardiomyopathy (TIC) seems to be a form of reversible cardiomyopathy. With recurrence, TIC can be more severe and may increase the risk for sudden cardiac death. OBJECTIVE: We postulate that negative remodeling persists even though ejection fraction (EF) normalizes after appropriate treatment in these patients. METHODS: We analyzed 2-dimensional echocardiographic parameters of 24 patients with TIC (male: 21; age: 64.1 +/- 15.2 years; atrial arrhythmias: 92%) that improved significantly with treatment (mean time between pretreatment and posttreatment echocardiography: 14 +/- 6 months) and compared them with that of age-, gender-, and ejection fraction-matched control subjects without a history of TIC. RESULTS: The majority of posttreatment echocardiographic parameters showed a significant improvement (P <.05) with treatment in patients with TIC, including left ventricular (LV) ejection fraction (31.2% +/- 8.2% to 55.0% +/- 5.7%) and LV end systolic volume index (55 +/- 21 ml/m(2) to 33 +/- 13 ml/m(2)). There was no significant difference in LV end diastolic volume index (78 +/- 22 ml/m(2) to 72 +/- 22 ml/m(2), P = .15). However, when compared with age-, gender-, and ejection fraction-matched control subjects, posttreatment echocardiographic parameters in TIC patients showed significant differences (TIC vs control group) in LV end systolic volume index (33 +/- 13 ml/m(2) vs 22 +/- 5 ml/m(2)), LV end diastolic volume index (72 +/- 22 ml/m(2) vs 51 +/- 12 ml/m(2)), and cardiac index (2.6 +/- 0.8 l/min/m(2) vs 1.8 +/- 0.6 l/min/m(2)). CONCLUSION: Although the majority of echocardiographic parameters, including EF, improved significantly with treatment in TIC patients, LV dimensions and volumes remained significantly elevated when compared with control subjects, indicating persistence of negative LV remodeling, even after appropriate treatment and normalization of EF at a mean follow-up of 14 months.

Prediction of ischemic events by anatomic M-mode strain rate stress echocardiography.

OBJECTIVE: We assessed the prognostic value of anatomic M-mode strain rate stress echocardiography (SRSE) in patients with known or suspected coronary artery disease. Previous studies showing that M-mode SRSE may be an accurate method for detection of coronary artery disease suggest that this technique may be useful for risk stratification. METHODS: M-mode SRSE, using a color-coded display of strain rate (SR), was performed in 358 patients (48, dobutamine; 68, bicycle; 242, treadmill). SR was graded by visual assessment of the color-coded display in 12 apical segments. Abnormal rest SR was defined as SR more positive than -1/s (green-yellow). Ischemia was defined by the development of post-systolic shortening or lack of improvement of SR to more negative than -2/s (brown hue) with stress. Patients were followed for cardiac events. RESULTS: Twelve patients with early intervention for an abnormal two-dimensional stress echocardiogram or stress electrocardiogram were excluded. Follow-up (mean 10.7 months) was completed in 98% (338/346) of the remaining patients. Events occurred in 1.7% (4/230) of patients with normal SRSE compared with 10% (11/108) with abnormal SRSE (P = .002). The annualized hard event (infarction, death) rate in those with normal SRSE was 0.5% versus 7.2% in those with abnormal SRSE (P = .001). Smoking (P = .048, relative risk 2.91), nitrate use (P = .001, relative risk 7.81), and the severity of the abnormality on SRSE (P = .009, relative risk 1.75) independently predicted events. Wall motion assessment was not predictive. Patients with normal SRSE had better event-free survival compared with those with abnormal SRSE (P < .001). CONCLUSION: SRSE is an independent predictor of outcome. A normal SRSE predicts a low risk of infarction or death in short-term follow-up.

Reduced right ventricular systolic function in constrictive pericarditis indicates myocardial involvement and persistent right ventricular dysfunction and symptoms after pericardiectomy.

We report four cases of patients with documented constrictive pericarditis who had evidence of reduced right ventricular (RV) systolic function. Assessment of RV systolic function was performed by pulsed tissue Doppler sampling of basal RV free wall velocity at the level of the tricuspid annulus in the four-chamber view. Velocity values and time velocity integral calculated from the velocity envelope were compared with values from controls. All four patients had evidence of epicardial RV injury at the time of pericardiectomy and persistent symptoms and RV systolic dysfunction after pericardiectomy.

Stress-induced wall motion abnormalities with low-dose dobutamine infusion indicate the presence of severe disease and vulnerable myocardium.

BACKGROUND: Patients with left ventricular (LV) systolic dysfunction due to coronary artery disease (CAD) may develop stress-induced wall motion abnormalities (SWMA) with low-dose (10 microg/kg/min) dobutamine infusion. The clinical significance of low-dose SWMA is unknown. OBJECTIVE: We investigated the clinical, hemodynamic and angiographic correlates of low-dose SWMA in patients with chronic ischemic LV systolic dysfunction. METHODS: Seventy patients with chronic ischemic LV systolic dysfunction who had dobutamine stress echocardiography were studied. Clinical, hemodynamic, and angiographic parameters at rest and low-dose were compared between 38 patients (mean ejection fraction (EF) of 30 +/- 8%) with low-dose SWMA and 32 patients (EF 30 +/- 11%) without low-dose SWMA. RESULTS: Multivariate analysis showed that the number of coronary territories with severe disease (stenosis > or =70%)(P = 0.001, RR = 6.3) was an independent predictor of low-dose SWMA. An increasing number of collateral vessels protected patients from low-dose SWMA (P = 0.011, RR = 0.25). A higher resting heart rate was a negative predictor of low-dose SWMA (P = 0.015, RR = 0.92) but no other hemodynamic variables were predictors. In the patients with low-dose SMA, regions with low-dose SWMA were more likely to be supplied by vessels with severe disease than regions without low-dose SWMA (92% vs 58%, P < 0.001). CONCLUSION: In patients with ischemic LV systolic dysfunction, the extent of severe disease and a lower numbers of collaterals predict the occurrence of low-dose SWMA. Low-dose SWMA is a highly specific marker for severe disease.

Out-of-hemodialysis-unit blood pressure is a superior determinant of left ventricular hypertrophy.

Blood pressures (BPs) obtained in the dialysis unit correlate poorly with ambulatory BP and left-ventricular hypertrophy (LVH). We compared the performance of BP obtained within and outside the dialysis unit as a correlate of LVH. BP was obtained in the dialysis unit using routine and standardized methods and outside the dialysis unit using home and ambulatory BP monitoring in 140 patients (mean age, 56 years; 89 men; 129 blacks; and 59 with diabetes mellitus) on chronic hemodialysis for > or =3 months. Dialysis unit BP recordings were averaged over 2 weeks, and home BP averaged over 1 week. Ambulatory BP monitoring was performed during an interdialytic interval. Echocardiography was performed immediately after dialysis for the assessment of left-ventricular mass. Left ventricular mass/height(2.7) of >51 g/m2 was taken as evidence of LVH. Test performance of various BPs was compared using receiver operating characteristic curves. Average ambulatory BP was 129.7+/-21.2/73.6+/-13.1 mm Hg, home BP was 139.4+/-21.2/79.0+/-12.5 mm Hg, standardized predialysis BP was 142.1+/-21.7/74.9+/-13.3 mm Hg, postdialysis was 120.9+/-20.8/69.6+/-12.5 mm Hg, routine predialysis was 145.6+/-20.7/79.4+/-13.1 mm Hg, and postdialysis was 132.0+/-19.3/72.6+/-11.1 mm Hg. Left ventricular mass/height(2.7) was 59.1+/-16.5, and 68% had LV hypertrophy. Diastolic BP measured by any technique was not associated with LVH. Routine and standardized measurements of BP were similarly weak correlates of LVH. Systolic BP outside the dialysis unit was a stronger correlate of LVH compared with dialysis unit BP.