Prognostic value of dobutamine-atropine stress echocardiography for peri-operative and late cardiac events in patients scheduled for vascular surgery

Atropine first is safer than conventional atropine administration in older people undergoing dobutamine stress echocardiography

OBJECTIVE

Early injection of atropine during dobutamine stress echocardiography (DSE) has been demonstrated in retrospective analyses to reduce the duration and dose of dobutamine infusion, while preserving a similar diagnostic accuracy with a lower incidence of adverse effects. This study explores the safety of using atropine as a start drug before dobutamine infusion (ADSE protocol) in comparison with the conventional protocol (DASE protocol) in older patients undergoing DSE for ischemia evaluation.

METHODS

One hundred consecutive older patients were prospectively enrolled. When eligible, they were randomly assigned to undergo either the DASE protocol (group A, 50 patients) or the ADSE protocol (group B, 50 patients) when atropine (1.0 mg) was first administered 3 min before dobutamine infusion followed by 0.5 mg increments (maximum 1.0 mg) thereafter. Patients were monitored for adverse drug effects. Test duration was calculated.

RESULTS

The mean age of the whole study cohort was 67.8±4.3 years and 58 (58%) were men. Patients in group A had longer test duration (21.8±1.3 versus 13.7±0.77 min, p<0.001) and higher mean dobutamine infusion rate (39±8.2 versus 28.2±9.5 μg/kg/min, p<0.001). The two groups received a similar total dose of atropine. Group A patients showed significantly higher incidence of extrasystoles, nonsustained ventricular tachycardia and severe hypotension (p<0.05).

CONCLUSION

In older patients undergoing DSE, using atropine as a start drug, that is, adopting the ADSE protocol, is associated with shorter test duration, lower mean dobutamine infusion rate and consequently fewer adverse effects.

Value of myocardial viability estimation using dobutamine stress echocardiography in assessing risk preoperatively before noncardiac vascular surgery in patients with left ventricular ejection fraction <35%

Patients with heart failure (HF) scheduled for vascular surgery have an increased risk of adverse postoperative outcome, and stratification usually depends on dichotomous risk factors. A quantitative prognostic model for patients with HF was developed using wall motion patterns during dobutamine stress echocardiography (DSE). A total of 295 consecutive patients (mean age 67 +/- 12 years) with ejection fraction < or =35% were studied. During DSE, wall motion patterns of dysfunctional segments were scored as scar, ischemia, or sustained improvement. Cardiac death and myocardial infarction were noted perioperatively and during 5 years of follow-up. Of 4,572 dysfunctional segments; 1,783 (39%) had ischemia, 1,280 (28%) had sustained improvement, and 1,509 (33%) had scar. In 212 patients, > or =1 ischemic segment was present; 83 had only sustained improvement. Perioperative and late cardiac event rates were 20% and 30%, respectively. Using multivariate analysis, number of ischemic segments was associated with perioperative cardiac events (odds ratio per segment 1.6, 95% confidence interval 1.05 to 1.8), whereas number of segments with sustained improvement was associated with improved outcome (odds ratio per segment 0.2, 95% confidence interval 0.04 to 0.7). Multivariate independent predictors of late cardiac events were age and ischemia. Sustained improvement was associated with improved survival. In conclusion, DSE provides accurate risk stratification of patients with HF undergoing vascular surgery.

Role of Contrast-Enhanced Dobutamine Stress Echocardiography in Predicting Outcome in Patients with Known or Suspected Coronary Artery Disease

Although the application of intravenous contrast agents during stress echocardiography has been shown to improve diagnostic accuracy for detecting coronary artery disease, less information exists regarding its prognostic value. The aim of this study was to determine the role of contrast-enhanced dobutamine stress echocardiography (DSE) for predicting future cardiac events in patients with coronary artery disease (CAD). We studied 893 patients (mean age: 66, 581 men) with known or suspected CAD undergoing contrast-enhanced DSE. Positivity was defined as new/worsened wall motion abnormality or fixed abnormality during stress. All patients were followed for 15 +/- 10 months to evaluate hard cardiac events (cardiac death and nonfatal myocardial infarction) and total cardiac events (hard cardiac events, congestive heart failure, unstable angina, and late revascularization). Three patients were lost to follow-up, and 128 patients developed cardiac events, including 21 hard cardiac events. The 3-year event free survival rate was significantly lower in patients with positive DSE results than in those with negative DSE results. Stepwise Cox multivariate analysis revealed that positivity of DSE (P < 0.0001, Hazard ratio (HR): 2.48) and peak wall motion score index (WMSI) >1.5 (P < 0.0001, HR: 2.41) were independent predictors for total cardiac events. Considering hard cardiac events, the independent predictors were peak WMSI > 1.5 (P < 0.0001, HR: 6.65) and age > 70 years (P < 0.005, HR: 3.27). We conclude that contrast-enhanced DSE provides important prognostic information for future cardiac events.

Quantitative Assessment of Left Ventricular Function During Contrast-Enhanced Dobutamine Stress Echocardiography Predicts Future Cardiac Events in Diabetic Patients

BACKGROUND

Non-invasive diagnosis and risk stratification of coronary artery disease are important for the selection and optimization of therapeutic interventions in diabetic patients, which may improve survival. The aim of this study was to determine the incremental value of contrast-enhanced dobutamine stress echocardiography (CE-DSE) for risk stratification.

METHODS AND RESULTS

CE-DSE was performed in 326 patients with diabetes mellitus (mean age; 66 +/- 10 years, 223 men). All patients were followed up for a mean of 29 months (1-61 months). Dobutamine was infused in a standard protocol with an intravenous contrast agent. The primary endpoints for hard cardiac events included cardiac death and nonfatal myocardial infarction. The primary endpoints for total cardiac events included hard cardiac events, unstable angina pectoris, congestive heart failure, and late coronary revascularization (> 3 months). Cardiac events occurred in 74 patients. The addition of the CE-DSE results, including abnormal left ventricular end-systolic volume response and left ventricular ejection fraction at peak stress < 50%, to the clinical and rest echocardiography model provided incremental information in predicting total cardiac events (increase in chi-square value for the model from 17 to 24, p < 0.05) and hard cardiac events (increase in chi-square value for the model from 18 to 24, p < 0.05).

CONCLUSIONS

Quantitative assessment of left ventricular function during CE-DSE provides incremental prognostic information in predicting cardiac events in diabetic patients.

Very late survival after vascular surgery

PURPOSE

The aim of this study was to define very late survival in veterans who routinely underwent preoperative assessment of left ventricular function using radionuclide ventriculography (RNVG) before elective major vascular surgery from 7/84 to 7/88 at one Veterans Affairs Medical Center.

METHODS

RNVG defined left ventricular ejection fraction (EF) and determined the presence of ventricular wall motion abnormalities. Patients undergoing elective vascular surgery (n = 310) who had preoperative RNVG were then followed over the years using direct contact, VA administrative databases, and, most recently, the Social Security Death Index.

RESULTS

Follow-up was 6.64 +/- 4.62 years (range 0 to 16.2 years). Current survival is 10% (11/107) after carotid surgery, 12% (10/82) after aortic aneurysm repair, 15% (17/111) after extremity reconstruction, and 0% (0/10) after visceral artery reconstruction (ns). There was no statistically significant difference in mortality between the different types of vascular surgery at 30 days or at 1, 5, and 10 years after surgery (ns). Actual survival rates at 5 years after carotid surgery, aneurysm repair, extremity reconstruction, and visceral reconstruction were 55, 61, 59, and 50%, respectively. Stepwise logistic regression analysis was performed which included preoperatively defined cardiovascular risk factors, type of surgery, and results of RNVG. The final regression model indicated that age, diabetes, smoking at the time of surgery, and low EF were independently associated with overall mortality while angina, prior myocardial infarction (MI), and type of operation were not. Mean survival duration with normal EF (>50%) was 7.99 years versus 4.78 years with low EF (P < 0.001). No patient with severe left ventricular dysfunction (EF < or = 35%; n = 39) or who had postoperative cardiac complications (MI, CHF, ventricular arrhythmia; n = 38) survived to the present.

CONCLUSIONS

Very late survival after major vascular surgery was related to the presence of diabetes, active smoking at the time of surgery, left ventricular function, and postoperative cardiac complications. Since there was no association of overall mortality with angina or prior MI, an aggressive approach to coronary evaluation in such patients might not alter very late survival.

[The role of dobutamine stress echocardiography in the clinical routine of a department of cardiology]

BACKGROUND

The aim of this study was to assess the role of dobutamine stress echocardiography (SE) for diagnosis and therapy of coronary artery disease (CAD) in the routine practice of a cardiological department in which bicycle stress-testing, scintigraphy and coronary angiography are available.

METHODS

Between January 1997 and September 1998, 123 patients (79 men, 44 women, 60.1 +/- 9.9 years) underwent SE. SE-indication, SE-result and the consequence of the SE were registered. A telephone follow-up, asking for events and cardiac interventions, took place after at least one year.

RESULTS

SE was performed in 57 patients with suspected CAD and in 66 patients with known CAD. The indications were inconclusive bicycle stress-testing or perfusion scintigrams (n = 77), search for hibernation (n = 22), discrepancy between presenting symptoms and results of previous investigations (n = 14) and preoperative risk stratification (n = 10). In the group with suspected CAD, the proportion of female patients was higher (p = 0.001), in the group with known CAD the proportion of male patients was higher (p = 0.002). SE showed an ischemic reaction in 35 patients, hibernation in 24 patients, no ischemic reaction in 56 patients and was inconclusive in 8 patients. The consequence of SE was recommendation for diagnostic coronary angiography (n = 27), revascularisation (n = 10), abstention from any invasive intervention (n = 77), noncardiac surgery (n = 9) and electrophysiological investigation (n = 1). During the investigated period, 955 bicycle stress-tests, 677 Thallium scintigrams and 987 coronary angiograms were carried out. During the follow-up (15 +/- 2.9 months) 4 patients died. In 6 patients cardiac interventions were carried out. No differences were observed regarding events and interventions depending on SE results and consequences.

CONCLUSIONS

At a cardiological department SE plays a role if findings are inconclusive and if hibernation or operative risk is looked for. A negative SE result most commonly leads to abstention from invasive intervention. If the SE result is positive, the recommendation for invasive intervention is also influenced by the clinical symptoms and the size of the ischemically reacting myocardium.

Cardiac Investigation and Intervention Prior to Thoraco-abdominal Aneurysm Repair: Coronary Angiography in 35 Patients

OBJECTIVE

retrospective studies indicate a high risk of cardiac events in patients undergoing thoraco-abdominal aneurysm repair. We aimed to determine the prevalence of coronary disease in these patients, define the role of non-invasive cardiac testing and assess the short-term outcome of coronary re-vascularisation.

DESIGN

a prospective cohort study of consecutive patients referred to a single surgeon.

MATERIALS AND METHODS

forty patients recruited over 16 months (Type I, 6; II, 11; III, 8; IV, 15). Dobutamine stress echocardiography, coronary angiography and coronary re-vascularisation (PTCA or CABG) were performed according to a pragmatic protocol. Main outcome measures were the prevalence of coronary artery disease, sensitivity and specificity of clinical assessment and non-invasive cardiac testing, and adverse events associated with coronary investigation and intervention.

RESULTS

seven patients (17.5%) were stratified as having high perioperative cardiac risk. The majority of patients (23, 57.5%) had no cardiac risk factor other than the operation type. Five patients (12.5%) had inducible ischaemia on non-invasive testing. Fourteen patients (40%) had haemodynamically significant coronary artery stenoses, of whom 12 (34%) underwent coronary revascularisation. Dobutamine stress echocardiography demonstrated 100% specificity and 71% sensitivity for the detection of significant coronary artery lesions. Coronary re-vascularisation by three-vessel bypass grafting was complicated by non-fatal stroke in one patient. Thirty-five patients (87.5%) proceeded to aneurysm repair. No patient who had been adequately investigated suffered a cardiac complication.

CONCLUSIONS

the 40% prevalence of coronary artery disease in these patients is comparable to that of other patients undergoing arterial surgery. Non-invasive testing proved beneficial, both in screening low-risk patients and planning intervention in patients at higher risk. An aggressive approach to intervention was associated with an acceptable complication rate and favourable short-term outcome.

Diagnostic and prognostic use of stress echocardiography in stable patients

Stress echocardiography is an effective diagnostic and prognostic technique in stable patients with known or suspected coronary artery disease (CAD), myocardial infarction, or chronic left ventricular dysfunction and those undergoing noncardiac surgery. Stress echocardiography is sensitive and specific for the detection and extent of CAD. Negative tests confer a high negative predictive value for cardiac events regardless of the clinical risk. Positive studies confer a high positive predictive value for ischemic events in patients with intermediate to high clinical risk. Stress echocardiography provides incremental prognostic information relative to clinical, resting echocardiographic, and angiographic data. Meta-analysis studies have shown that the diagnostic and prognostic information provided by stress echocardiography is comparable to that from radionuclide scintigraphic stress tests. Stress echocardiography may be more specific for the detection and extent of CAD, whereas radionuclide scintigraphy may be more sensitive for one-vessel disease. Sensitivities are similar for the detection and extent of disease in patients with multivessel CAD.

Usefulness of hypotension during dobutamine echocardiography in predicting perioperative cardiac events

This study was undertaken to determine the prognostic significance of hypotension induced during preoperative dobutamine stress echocardiography (DSE) before vascular and noncardiac thoracic surgery. Wall motion abnormality during DSE predicts perioperative risk. Although hypotension during DSE has not been shown to correlate with the presence or severity of coronary artery disease, its significance in perioperative risk assessment is unknown. We retrospectively studied 300 patients who had DSE within 6 months of noncardiac surgery. Perioperative events including death, myocardial infarction, ischemia, and arrhythmias were recorded. Odds ratios with 95% confidence intervals were used to examine the association between clinical and echocardiographic variables and perioperative events. A hypotensive response during DSE was seen in 85 patients (28%). Forty-eight patients (16%) had 54 perioperative complications including 4 cardiac-related deaths, 10 myocardial infarctions, 12 myocardial ischemic events, and 28 arrhythmias. Hypotension during DSE was predictive of the combined end point of perioperative cardiac mortality, myocardial infarction, and ischemia (odds ratio 4.04, 95% confidence interval 1.72 to 9.51). In a multivariate logistic regression model, hypotension during DSE remained a significant predictor (odds ratio 4.10, p<0.01). DSE-related hypotension was predictive of perioperative cardiac events and therefore may have a role in risk stratification before vascular or noncardiac thoracic surgery.

Diagnostic and Prognostic Use of Stress Echocardiography and Radionuclide Scintigraphy

Stress echocardiography and radionuclide scintigraphy are effective diagnostic and prognostic techniques in patients with known or suspected coronary artery disease (CAD), myocardial infarction (MI), chronic left ventricular dysfunction (LVD), and those undergoing noncardiac surgery. Both are sensitive and specific for the detection and extent of CAD. Negative tests confer a high negative predictive value for cardiac events irrespective of clinical risk. Positive studies confer a high positive predictive value for ischemic events in patients with intermediate to high clinical risk. Both provide incremental diagnostic and prognostic information relative to clinical, resting echocardiographic, and angiographic data. Meta-analysis studies have shown that the diagnostic and prognostic information provided by stress echocardiography is comparable with radionuclide scintigraphic stress tests. Stress echocardiography may be more specific for the detection and extent of CAD, whereas radionuclide scintigraphy may be more sensitive for single-vessel disease. Sensitivities are similar for the detection and extent of disease in patients with multivessel CAD.

Dobutamine stress echocardiography for the preoperative evaluation of patients undergoing lung volume reduction surgery

BACKGROUND

Lung volume reduction surgery has been proposed as a bridge to lung transplantation and as definitive therapy for advanced chronic obstructive lung disease. However, patient selection criteria and optimal preoperative assessment have not been clearly defined.

OBJECTIVE

We investigated the feasibility, safety, and value of dobutamine stress echocardiography as a predictor of major early cardiac events in patients who underwent lung volume reduction surgery.

METHODS

The study population consisted of 46 patients (21 men and 25 women, mean age 59 +/- 9 years) who underwent dobutamine stress echocardiography (maximum dose 40 microg. kg(-1). min(-1) plus atropine if needed) 180 days or less before lung volume reduction surgery. Adverse cardiac events were prospectively defined and tabulated during hospitalization after the operation and at subsequent outpatient visits.

RESULTS

Dobutamine stress echocardiography was interpretable in 45 of 46 (98%) patients. There were no adverse events during testing. The studies revealed normal left ventricular systolic function at rest in all patients and normal right ventricular function in all patients but one. Thirteen patients had right ventricular enlargement. Estimated right ventricular systolic pressure was mildly elevated (>40 mm Hg) in 5 patients. Four patients (9%) had stress tests positive for ischemia. There were no perioperative deaths. Follow-up was available for 44 of 45 patients at a duration of 20.0 +/- 7.0 months. Two major adverse cardiac events occurred in the same patient in whom the results of dobutamine stress echocardiography were positive for ischemia (positive predictive value 25%, 95% confidence interval 0% to 83%; negative predictive value 100%, 95% confidence interval 90 to 100%).

CONCLUSION

Despite end-stage chronic obstructive lung disease and poor ultrasound windows, dobutamine stress echocardiography is feasible and safe in patients undergoing evaluation for lung volume reduction surgery. It yields important information on right and left ventricular function and has an excellent negative predictive value for early and late adverse cardiac events.

Exercise echocardiography. Principles, methods, and clinical use

Stress echocardiography is composed of a family of examinations in which various forms of cardiovascular stress are combined with echocardiographic imaging to assist in the diagnosis of coronary artery disease. Exercise cardiography has evolved over the past 20 years into a routinely available clinical tool employed in both university and community hospital settings. This article discusses advantages and disadvantages of using exercise echocardiography.

Prognosis of patients with vascular disease after clinical evaluation and dobutamine stress echocardiography

BACKGROUND

Coronary disease is an important cause of long-term morbidity in patients needing major vascular surgery. We sought to assess the efficacy of preoperative clinical evaluation and the detection of inducible ischemia for prediction of immediate and long-term cardiac outcomes of patients undergoing vascular surgery.

METHODS

In 233 patients undergoing vascular procedures, we assessed risk clinically on the basis of Eagle's criteria. Dobutamine echocardiography was performed with a standard protocol and results were classified as showing ischemia, scar, or a normal response. Patients were observed perioperatively, and late follow-up (28 +/- 13 months) was completed in all surgical survivors. A composite end point of cardiac death, myocardial infarction, and unstable and progressive angina requiring late revascularization was used to judge event-free survival.

RESULTS

Of 233 patients undergoing preoperative dobutamine echocardiography, 39 (17%) had inducible ischemia and 36 (15%) had scar. Perioperative events occurred in 8 patients (3%). None of the patients with ischemia had perioperative events, reflecting the effect of revascularization in 9 patients. Late events occurred in 36 patients; ischemia on preoperative stress testing was a predictor of these events even after adjusting for clinical variables and left ventricular dysfunction (relative risk = 3.3; 95% confidence interval 1.6 to 6.8; P =.001). The association of ischemia with clinical predictors was associated with incrementally worse outcome.

CONCLUSION

In addition to perioperative assessment, the combined use of clinical and dobutamine echocardiographic evaluation may stratify the risk of late cardiac events.

Clinical determinants in perioperative cardiac evaluation

Perioperative cardiac events are the largest cause of morbidity and mortality for patients undergoing elective surgery. As a result, numerous recent studies have focused on attempts to identify patients at increased risk for perioperative events. These have delineated testing modalities capable of identifying high-risk patients, and clinical markers which further stratify patients facing elective surgery into high-, medium-, and low-risk subgroups. In this article, the authors review the evidence supporting the use of clinical markers of risk to evaluate patients before elective surgery. The role of preoperative clinical assessment in identifying patients most likely to benefit from further testing or intervention, (ie, those at significant risk for short- and long-term cardiac events) is stressed. Assessment and intervention for risk factors of long-term cardiac disease is also stressed, as the preoperative evaluation represents an opportunity for improvement in the short- and long-term cardiac risk profile. Finally, the algorithm for preoperative cardiovascular evaluation published jointly by the ACC/AHA joint taskforce on practice guidelines is reviewed. This algorithm is a synthesis of the current literature, into a cost effective and efficient approach to patient evaluation.