Jelena Stepanovic

Stress echocardiography in the detection of myocardial ischemia. Head-to-head comparison of exercise, dobutamine, and dipyridamole tests.

BackgroundExercise and pharmacological stress echocar-diography have emerged as convenient alternatives to myocardial scintigraphy. The objective of this study was to compare in the same patients the diagnostic values of exercise, dobutamine, and dipyridamole stress echocardiography tests for detection of myocardial ischemia. Methods and ResultsWe performed exercise (maximal treadmill Bruce protocol), dobutamine (up to 40 μg/kg per minute) and dipyridamole (up to 0.84 mg/kg over 10 minutes) stress echocardiography tests, in random sequence and on separate days, in 136 consecutive patients. All patients underwent coronary angiography. Significant coronary artery disease was defined by quantitative coronary angiography as a lesion with a diameter stenosis ≥50%. A stress echocardiogram was considered positive when new or worsening of preexisting wall motion abnormality was observed. Most of the patients (94%) were receiving the same antianginal medication for each stress test; 59 patients were receiving concomitant β-blocker therapy. The prevalence of coronary artery disease was 87.5%, with 108 patients having one-vessel coronary artery disease. Peak heart rate and systolic blood pressure were higher with exercise than with dobutamine or dipyridamole (P<.01). Sensitivity of exercise, dobutamine, and dipyridamole stress echocardiography was 88%, 82%, and 74% (dipyridamole versus exercise, P<.01), respectively. Specificity was 82%, 77%, and 94%, respectively. The overall accuracy was 87%, 82%, and 77% (dipyridamole versus exercise, P<.01), respectively. The accuracy of dipyridamole was higher (P=.02) in the group of patients not receiving β-blockers (84%) than in the patients receiving β-blocker therapy (66%), whereas the accuracy of exercise and dobutamine were only slightly higher in the patients not receiving, β-blockers. Significant side effects occurred in 3%, 11%, and 1% of patients during exercise, dobutamine, and dipyridamole tests, respectively. ConclusionsDespite the different hemodynamic effects, exercise, dobutamine, and dipyridamole echocardiography have high overall diagnostic values. In this group of patients with a predominance of one-vessel coronary artery disease, the overall diagnostic accuracy of stress echocardiography tests was higher for exercise than for dobutamine or dipyridamole. Concomitant β-blocker therapy significantly decreased the accuracy of the dipyridamole stress echocardiography test. Pharmacological stress testing (dipyridamole without β-blockers) can therefore be used as an efficient option for detection of myocardial ischemia in patients who are unable or poorly motivated to exercise adequately.

Dipyridamole-dobutamine echocardiography: A novel test for the detection of milder forms of coronary artery disease

OBJECTIVES This study was designed to assess the clinical, hemodynamic and diagnostic effects of the addition of dobutamine to dipyridamole echocardiography. BACKGROUND Pharmacologic stress echocardiography with either dipyridamole or dobutamine has gained acceptance because of its safety, feasibility, diagnostic accuracy and prognostic power. The main limitation of the two tests is a less than ideal sensitivity in some patient subsets, such as those with limited coronary artery disease. We hypothesized that two pharmacologic stresses might act synergistically in the induction of ischemia by combining the mechanisms of inappropriate coronary vasodilation (with dipyridamole) and an increase in myocardial oxygen consumption (with dobutamine). METHODS One hundred fifty patients (mean [+/- SD] age 51 +/- 11 years) referred for stress echocardiography were initially studied by dipyridamole-dobutamine echocardiography. The test was stopped during the dipyridamole step in 95 patients for achievement of a predetermined end point (obvious dyssynergy induced by lower or higher dipyridamole dose), and dipyridamole-dobutamine tests were performed in 55 patients (negative dipyridamole echocardiographic test). In the same 150 patients the dobutamine echocardiographic test (up to 40 micrograms/kg body weight per min) was performed on a separate day. RESULTS Significant coronary artery disease (> 50% diameter stenosis of at least one major coronary vessel by quantitative coronary arteriography) was present in 131 patients (one vessel in 115; two vessels in 10, three vessels in 6), with normal coronary arteriography in 19. The feasibility of the dipyridamole-dobutamine test was 96%. Self-limiting side effects occurred in 5% of patients. The peak rate-pressure product was lowest during the dipyridamole test (132 +/- 30) and was comparable during the dobutamine (186 +/- 59) and dipyridamole-dobutamine tests (179 +/- 45, p = NS vs. dobutamine; p < 0.01 vs. dipyridamole). Sensitivity was 71% for dipyridamole, 75% for dobutamine and 92% for dipyridamole-dobutamine echocardiography (dipyridamole vs. dipyridamole-dobutamine, p < 0.01; dobutamine vs. dipyridamole-dobutamine, p < 0.01; dipyridamole vs. dobutamine, p = NS), whereas specificity was 89% for dipyridamole, 79% for dobutamine and 89% for dipyridamole-dobutamine echocardiography (p = NS for all). CONCLUSIONS Routine dobutamine addition to dipyridamole stress testing is clinically useful and well tolerated. It expands the spectrum of the disease detectable by pharmacologic stress echocardiography and allows documentation of milder forms of coronary artery disease that can be missed by conventional dipyridamole or dobutamine stress echocardiography.

Integrated evaluation of relation between coronary lesion features and stress echocardiography results: the importance of coronary lesion morphology

OBJECTIVES The aim of this study was to analyze, in the same group of patients, the relationship between multiple variables of coronary lesion and results of exercise, dobutamine and dipyridamole stress echocardiography tests. BACKGROUND Integrated evaluation of the relation between stress echocardiography results and angiographic variables should include not only the assessment of stenosis severity but also evaluation of other quantitative and qualitative features of coronary stenosis. METHODS Study population consisted of 168 (138 male, 30 female, mean age 51+/-9 years) patients, on whom exercise (Bruce treadmill protocol), dobutamine (up to 40 mcg/kg/min) and dipyridamole (0.84 mg/kg over 10 min) stress echocardiography tests were performed. Stress echocardiography test was considered positive for myocardial ischemia when a new wall motion abnormality was observed. One-vessel coronary stenosis ranging from mild stenosis to complete obstruction of the vessel was present in 153 patients, and 15 patients had normal coronary arteries. The observed angiographic variables included particular coronary vessel, stenosis location, the presence of collaterals, plaque morphology according to Ambrose classification, percent diameter stenosis and obstruction diameter as assessed by quantitative coronary arteriography. RESULTS Covariates significantly associated with the results of physical and pharmacological stress tests included for all three stress modalities presence of collateral circulation, percent diameter stenosis and obstruction diameter, as well as lesion morphology (p < 0.05 for all, except collaterals for dobutamine stress test, p = 0.06). By stepwise multiple logistic regression analysis, the strongest predictor of the outcome of exercise echocardiography test was only percent diameter stenosis (p = 0.0002). However, both dobutamine and particularly dipyridamole stress echocardiography results were associated not only with stenosis severity - percent diameter stenosis (dobutamine, p = 0.04; dipyridamole, p = 0.003) - but also, and even more strongly, with lesion morphology (dobutamine, p = 0.006; dipyridamole, p = 0.0009). As all of stress echocardiography results were significantly associated with percent diameter stenosis, the best angiographic cutoff in relation to the results of stress echocardiography test was: exercise, 54%; dobutamine, 58% and dipyridamole, 60% (p < 0.05 vs. exercise). CONCLUSIONS Integrated evaluation of angiographic variables have shown that the results of dobutamine and dipyridamole stress echocardiography are not only influenced by stenosis severity but also, and even more importantly, by plaque morphology. The results of exercise stress echocardiography, although separately influenced by plaque morphology, are predominantly influenced by stenosis severity, due to a stronger exercise capacity in provoking myocardial ischemia in milder forms of coronary stenosis.

Mitral Annular Calcification Predicts Cardiovascular Morbidity and Mortality in Middle-aged Patients With Atrial Fibrillation: The Belgrade Atrial Fibrillation Study

BACKGROUND Mitral annular calcification (MAC) has been suggested as a reliable, time-averaged marker of atherosclerosis and is associated with coronary artery disease, heart failure, ischemic stroke, and increased mortality. Data on the relationship between MAC and cardiovascular morbidity and mortality in atrial fibrillation (AF) are sparse, with the exception of the relationship between MAC and stroke. We investigated the association of MAC with cardiovascular morbidity, stroke, cardiovascular mortality, and all-cause death in a cohort of middle-aged patients with AF with a mean 10-year follow-up. METHODS This was an observational study of patients with nonvalvular AF between 1992 and 2007. RESULTS Of 1,056 patients, 33 (3.1%) had MAC; they were more likely to be older and female and to have a dilated left atrium, reduced left ventricular ejection fraction, permanent AF, hypertension, and/or diabetes mellitus (all P < .05). Total follow-up was 10,418.5 years (mean, 9.9 ± 5.9 years), and the mean age was 52.7 ± 12.2 years. In univariate analysis, MAC was associated with all-cause death, cardiovascular death, stroke, new cardiac morbidity (all P < .05), and the composite end point of ischemic stroke, myocardial infarction (MI), and all-cause death (P < .001). In multivariate analyses, MAC was related to all-cause death (hazard ratio [HR], 4.3; 95% CI, 1.8-10.0; P < .001), cardiovascular death (HR, 3.5; 95% CI, 1.2-10.4; P = .025), the composite end point (HR, 2.1; 95% CI, 1.0-4.3; P = .048), and new cardiac morbidity (HR, 2.4; 95% CI, 1.3-4.5; P = .005). There was no significant relationship between MAC and stroke or MI in the multivariate analyses. CONCLUSIONS MAC is associated with increased cardiovascular morbidity, cardiovascular mortality, and all-cause mortality of patients with AF. MAC should be acknowledged as a marker of increased cardiovascular risk in middle-aged patients with AF.

Original ResearchCardiovascular DiseaseMitral Annular Calcification Predicts Cardiovascular Morbidity and Mortality in Middle-aged Patients With Atrial Fibrillation: The Belgrade Atrial Fibrillation Study

BACKGROUND Mitral annular calcification (MAC) has been suggested as a reliable, time-averaged marker of atherosclerosis and is associated with coronary artery disease, heart failure, ischemic stroke, and increased mortality. Data on the relationship between MAC and cardiovascular morbidity and mortality in atrial fibrillation (AF) are sparse, with the exception of the relationship between MAC and stroke. We investigated the association of MAC with cardiovascular morbidity, stroke, cardiovascular mortality, and all-cause death in a cohort of middle-aged patients with AF with a mean 10-year follow-up. METHODS This was an observational study of patients with nonvalvular AF between 1992 and 2007. RESULTS Of 1,056 patients, 33 (3.1%) had MAC; they were more likely to be older and female and to have a dilated left atrium, reduced left ventricular ejection fraction, permanent AF, hypertension, and/or diabetes mellitus (all P < .05). Total follow-up was 10,418.5 years (mean, 9.9 ± 5.9 years), and the mean age was 52.7 ± 12.2 years. In univariate analysis, MAC was associated with all-cause death, cardiovascular death, stroke, new cardiac morbidity (all P < .05), and the composite end point of ischemic stroke, myocardial infarction (MI), and all-cause death (P < .001). In multivariate analyses, MAC was related to all-cause death (hazard ratio [HR], 4.3; 95% CI, 1.8-10.0; P < .001), cardiovascular death (HR, 3.5; 95% CI, 1.2-10.4; P = .025), the composite end point (HR, 2.1; 95% CI, 1.0-4.3; P = .048), and new cardiac morbidity (HR, 2.4; 95% CI, 1.3-4.5; P = .005). There was no significant relationship between MAC and stroke or MI in the multivariate analyses. CONCLUSIONS MAC is associated with increased cardiovascular morbidity, cardiovascular mortality, and all-cause mortality of patients with AF. MAC should be acknowledged as a marker of increased cardiovascular risk in middle-aged patients with AF.

High Dose Adenosine Stress Echocardiography for Noninvasive Detection of Coronary Artery Disease

OBJECTIVES The aim of this study was to assess the tolerability and incremental diagnostic value of high adenosine doses in stress echocardiography testing in patients with coronary artery disease (CAD). BACKGROUND In comparison with other pharmacologic stress echocardiography tests, standard dose adenosine stress has sub-optimal sensitivity for detecting milder forms of CAD. METHODS Adenosine stress echocardiography was performed in 58 patients using a starting dose of 100 micrograms/kg body weight per min over 3 min followed by 140 micrograms/kg per min over 4 min (standard dose). If no new wall motion abnormality appeared, the dose was increased to 200 micrograms/kg per min over 4 min (high dose). All patients underwent coronary angiography. Significant CAD was defined as > or = 50% diameter stenosis in at least one major coronary artery. Thirty-three patients had one-vessel and seven had multivessel CAD. Coronary angiographic findings were normal in 18 patients. RESULTS The high adenosine dose caused a slight but significant increase over baseline values in rate-pressure product. Limiting side effects occurred in two patients during the standard dose protocol and in one patient receiving the high dose regimen. The test was stopped in 30 patients after the standard adenosine dose regimen because of a provoked new wall motion abnormality. The sensitivity of adenosine echocardiography with the standard dose was 75% (95% confidence interval [CI] 63% to 87%). After completion of the standard dose protocol, 28 patients continued testing with the high dose adenosine protocol. The overall sensitivity of adenosine echocardiography, calculated as cumulative, increased to 92% (95% CI 84% to 100%) with the high dose (p < 0.05). The specificity of adenosine testing was 100% and 88%, respectively, with the standard and high dose regimen (p = 0.617). CONCLUSIONS We believe that use of a higher than usual adenosine dose protocol for stress testing may improve the diagnostic value of adenosine echocardiography, mainly by increasing sensitivity in patients with single-vessel disease without deterioration of the safety profile and with only a mild reduction in specificity.

Comparison of exercise, dobutamine-atropine and dipyridamole-atropine stress echocardiography in detecting coronary artery disease

BackgroundDipyridamole and dobutamine stress echocardiography testing are most widely utilized, but their sensitivity remained suboptimal in comparison to routine exercise stress echocardiography. The aim of our study is to compare, head-to-head, exercise, dobutamine and dipyridamole stress echocardiography tests, performed with state-of-the-art protocols in a large scale prospective group of patients.MethodsDipyridamole-atropine (Dipatro: 0.84 mg/kg over 10 min i.v. dipyridamole with addition of up to 1 mg of atropine), dobutamine-atropine (Dobatro: up to 40 mcg/kg/min i.v. dobutamine with addition of up to 1 mg of atropine) and exercise (Ex, Bruce) were performed in 166 pts. Of them, 117 pts without resting wall motion abnormalities were enrolled in study (91 male; mean age 54 ± 10 years; previous non-transmural myocardial infarction in 32 pts, angina pectoris in 69 pts and atypical chest pain in 16 pts). Tests were performed in random sequence, in 3 different days, within 5 day period under identical therapy. All patients underwent coronary angiography.ResultsSignificant coronary artery disease (CAD; ≥50% diameter stenosis) was present in 69 pts (57 pts 1-vessel CAD, 12 multivessel CAD) and absent in 48 pts. Sensitivity (Sn) was 96%, 93% and 90%, whereas specificity (Sp) was 92%, 92% and 87% for Dobatro, Dipatro and Ex, respectively (p = ns). Concomitant beta blocker therapy did not influence peak rate-pressure product and Sn of Dobatro and Dipatro (p = ns).ConclusionWhen state-of-the-art protocols are used, dipyridamole and dobutamine stress echocardiography have comparable and high diagnostic accuracy, similar to maximal post-exercise treadmill stress echocardiography.

The value of fractional and coronary flow reserve in predicting myocardial recovery in patients with previous myocardial infarction

AIMS The aim of the study was to evaluate the relation between fractional flow reserve (FFR) and simultaneously evaluated coronary flow reserve by thermodilution (CFRthermo), with the improvement of left ventricular (LV) function in patients with previous myocardial infarction (MI) undergoing percutaneous coronary intervention (PCI). METHODS AND RESULTS Study population consisted of 46 patients (mean age 53 +/- 7 years; 36 male) with previous MI and significant coronary stenosis undergoing PCI of infarct-related coronary artery. In all patients, we evaluated FFR and CFRthermo by single pressure/thermo wire during maximal hyperaemia before and immediately after PCI. We performed echocardiographic assessment of LV ejection fraction before and 6 months after PCI. Dobutamine stress echocardiography test was also performed before PCI. LV functional improvement was observed in 33/46 (72%) of patients. In patients with LV functional recovery in comparison with patients with no recovery, there was a significant difference in FFR before PCI (0.56 +/- 0.14 vs. 0.70 +/- 0.07, P < 0.001), improvement of FFR (0.35 +/- 0.14 vs. 0.21 +/- 0.07, P < 0.001), improvement of CFRthermo (1.3 +/- 0.6 vs. 0.5 +/- 0.3, P < 0.001), and CFRthermo after PCI (2.6 +/- 0.7 vs. 2.0 +/- 0.4, P < 0.001). When only parameters evaluated before PCI were taken into account, FFR before angioplasty (P = 0.001) and dobutamine-assessed viability (P = 0.006) were the most significant multivariate predictors of myocardial recovery. When all significant univariate parameters were evaluated, the most significant independent predictors for improvement in myocardial function were the improvement of CFRthermo during angioplasty (P < 0.001) and FFR before angioplasty (P = 0.002). CONCLUSION Simultaneous evaluation of FFR and CFRthermo provide significant complementary data on the improvement in myocardial function in patients with previous MI. However, the evaluation of FFR before angioplasty identifies viable myocardium that may recover following revascularization and may be used as an alternative to non-invasive testing.

Regional difference of microcirculation in patients with asymmetric hypertrophic cardiomyopathy: transthoracic Doppler coronary flow velocity reserve analysis.

OBJECTIVE To evaluate, by noninvasive coronary flow velocity reserve (CFVR), whether patients with asymmetric hypertrophic cardiomyopathy (HC), with or without left ventricular outflow tract obstruction, demonstrate significant regional differences of CFVR. METHODS We evaluated 61 patients with HC (27 men; mean age 49 ± 16 years), including 20 patients with hypertrophic obstructive cardiomyopathy (HOCM) and 41 patients without obstruction (HCM). The control group included 20 age- and sex-matched subjects. Transthoracic Doppler echocardiography CFVR of the left anterior descending coronary artery (LAD) and the posterior descending coronary artery (PD) were performed, including calculation of relative CFVR as the ratio between CFVR LAD and CFVR PD. RESULTS Compared with the controls, all the patients with HC had lower CFVR LAD (2.12 ± 0.53 vs 3.34 ± 0.67; P < .001) and CFVR PD (2.29 ± 0.49 vs 3.21 ± 0.65; P < .001). CFVR LAD in HOCM group in comparison with the HCM group was significantly lower (1.93 ± 0.42 vs 2.22 ± 0.55; P = .047), due to higher basal diastolic coronary flow velocities (0.40 ± 0.09 vs 0.33 ± 0.07 m/sec; P = .002), with similar hyperemic diastolic flow velocities (0.71 ± 0.16 vs 0.76 ± 0.19 m/sec; P = .330), respectively. There was no significant difference in CFVR PD between patients with HOCM and those with HCM (2.33 ± 0.46 vs 2.27 ± 0.50; P = .636), respectively. Relative CFVR was lower in the HOCM group compared with the HCM group (0.84 ± 0.16 vs 0.98 ± 0.14; P = .001). By multivariable regression analysis, left ventricular outflow tract gradient was the independent predictor of CFVR LAD (B = -0.24; P = .008) and relative CFVR (B = -0.34; P = .016). CONCLUSIONS CFVR LAD and relative CFVR were significantly lower in patients with HOCM compared with patients with HCM. Regional differences of CFVR are present only in patients with significant left ventricular outflow tract obstruction, which suggests that obstruction per se, by increasing wall stress in basal conditions, leads to higher basal diastolic coronary flow velocities and results in lower CFVR in LAD compared with PD.

Prediction of Myocardial Functional Recovery by Noninvasive Evaluation of Basal and Hyperemic Coronary Flow in Patients with Previous Myocardial Infarction

BACKGROUND The aim of this study was to evaluate the relation of basal and hyperemic coronary flow with myocardial functional improvement in patients with previous myocardial infarction undergoing elective percutaneous coronary intervention (PCI). METHODS Coronary flow was measured using transthoracic Doppler echocardiography in 50 patients (41 men; mean age, 53 ± 8 years) with previous myocardial infarction before, 24 hours, and 3 months after elective PCI. Diastolic deceleration time (DDT) was measured from the peak diastolic velocity to the point of intercept of initial decay slope with baseline. Coronary flow reserve (CFR) was calculated as the ratio of hyperemic to basal peak diastolic flow velocities. RESULTS In comparison with patients without improvements in left ventricular function, patients with recovered left ventricular function had longer DDTs before angioplasty (841 ± 286 vs. 435 ± 80 msec, P < .001). CFR was significantly higher in recovered compared with nonrecovered patients (2.60 ± 0.70 vs. 2.16 ± 0.34, P = .034) 24 hours after PCI. Global and regional wall motion scores before PCI, end-diastolic and end-systolic volumes, and CFR 24 hours after PCI and DDT before PCI were univariate predictors of left ventricular functional recovery. By multivariate analysis, DDT and regional wall motion score before PCI were independent predictors of left ventricular recovery in the follow-up period (P = .003 and P = .007, respectively). CONCLUSIONS In patients with previous myocardial infarction undergoing elective PCI, evaluation of basal coronary flow pattern and measurement of DDT before angioplasty may predict functional improvement of myocardium in the follow-up period and could be useful quantitative parameters in the evaluation of potential improvement in myocardial function.