Zorica Petrasinovic

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.

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.

One-year follow-up of myocardial perfusion and function evaluated by gated Spect Mibi in patients with earlier myocardial infarction and chronic total occlusion

ObjectiveOptimal treatment for chronic total occlusion (CTO) in the infarct-related coronary artery is not clear. Our aim was to assess myocardial perfusion, left ventricular ejection fraction (EF), and left ventricular size using gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging with 99mTc-methoxy-isobutyl-isonitrile in patients with CTO before and 1 year after recanalization. MethodsThirty patients with earlier myocardial infarction and at least one CTO underwent percutaneous coronary intervention (PCI) as well as nitrate-enhanced gated SPECT myocardial perfusion and dobutamine stress echocardiography before and 11±1 months after recanalization. They were divided into three groups based on the outcome of the follow-up angiography: (i) successful recanalization with no evidence of in-stent restenosis (n=13); (ii) successful recanalization with in-stent restenosis (n=7) and (iii) unsuccessful recanalization (n=10). ResultsOverall success of recanalization for CTO was 74%. In group 1, myocardial viability was preserved in 11 of 13 (85%) patients at baseline. Gated SPECT at 1 year showed a significant decrease in perfusion abnormalities (29±12 to 23±14%, P<0.05) and left ventricular end-diastolic volume (EDV) (168±47 to 151±47 ml, P<0.05). Improvement in EF (51±11 to 54±13%, P>0.05) and reduction in left ventricular end-systolic volume (ESV) (84±37 to 77±40 ml, P>0.05) did not reach the level of significance. Myocardial viability was preserved in only two of seven patients (28%) in group 2. Neither mean perfusion abnormalities (37±24 to 35±22%, P>0.05) nor global left ventricular parameters (EF 41±15 vs. 42±19%, EDV 298±33 vs. 299±57 ml, ESV 197±12 vs. 195±32 ml; P>0.05) changed at the follow-up. In group 3, myocardial viability was preserved in seven of 10 patients (70%) at baseline, but no significant changes in perfusion (40±18 vs. 41±19%, P>0.05) and left ventricular function (EF 42±17 vs. 44±14%, EDV 228±101 vs. 227±81 ml, ESV 143±87 vs. 146±8ml; P>0.05) were seen at the follow-up. ConclusionMyocardial perfusion and EDV may significantly improve 1 year after PCI provided recanalization of CTO was successful. Our preliminary findings suggest that successful recanalization of CTO may have favorable outcome on left ventricular perfusion and function, particularly in patients with viable myocardium before PCI. The gated SPECT myocardial perfusion imaging with 99mTc-methoxy-isobutyl-isonitrile may be useful for monitoring long-term functional outcome of PCI in patients with CTO.

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.

Mental stress-induced ischemia in patients with coronary artery disease: echocardiographic characteristics and relation to exercise-induced ischemia.

Objective The aims of this study were to investigate the incidence and parameters associated with myocardial ischemia during mental stress (MS) as measured by echocardiography and to evaluate the relation between MS-induced and exercise-induced myocardial ischemia. Methods Study participants were 79 patients (63 men; mean [M] [standard deviation {SD}] age = 52 [8] years) with angiographically confirmed coronary artery disease and previous positive exercise test result. The MS protocol consisted of mental arithmetic and anger recall task. The patients performed a treadmill exercise test 15 to 20 minutes after the MS task. Data of post–MS exercise were compared with previous exercise stress test results. Results The frequency of echocardiographic abnormalities was 35% in response to the mental arithmetic task, compared with 61% with anger recall and 96% with exercise (p < .001, exercise versus MS). Electrocardiogram abnormalities and chest pain were substantially less common during MS than were echocardiographic abnormalities. Independent predictors of MS-induced myocardial ischemia were: wall motion score index at rest (p = .02), peak systolic blood pressure (p = .005), and increase in rate-pressure product (p = .004) during MS. The duration of exercise stress test was significantly shorter (p < .001) when MS preceded the exercise and in the case of earlier exercise (M [SD] = 4.4 [1.9] versus 6.7 [2.2] minutes for patients positive on MS and 5.7 [1.9] versus 8.0 [2.3] minutes for patients negative on MS). Conclusions Echocardiography can be successfully used to document myocardial ischemia induced by MS. MS-induced ischemia was associated with an increase in hemodynamic parameters during MS and worse function of the left ventricle. MS may shorten the duration of subsequent exercise stress testing and can potentiate exercise-induced ischemia in susceptible patients with coronary artery disease.

Efficiency of Ergonovine Echocardiography in Detecting Angiographically Assessed Coronary Vasospasm

C vasospasm plays a major role in provoking myocardial ischemia in patients with variant angina, but also in some patients with acute coronary syndrome including unstable angina, myocardial infarction, and sudden death. Ergonovine provocation has been used for 20 years for detection of coronary artery spasm. Most data on ergonovine testing have been reported in the preselected group of patients with variant angina, establishing ergonovine as a test of high diagnostic confidence. In current clinical practice, when a marked decline in the use of ergonovine testing in the catheterization laboratory is observed, accompanied by promising reports on ergonovine echocardiography, a question remains on the incidence, safety, and usefulness of provocative testing for coronary vasospasm in patients with chest pain syndrome and nonsignificant coronary artery stenosis. Thus, the objectives of our study were to evaluate (1) the incidence of angiographically assessed coronary vasospasm in a consecutive population of patients with nonsignificant coronary artery disease, (2) the efficiency of simultaneously performed ergonovine echocardiography in identifying coronary vasospasm, and (3) the relation between ergonovine echocardiographic and angiographic results. • • • The vasomotor response to ergonovine was studied in 100 consecutive patients (45 men and 55 women, mean age 52 8 years) with chest pain syndrome and hemodynamically nonsignificant coronary stenosis (diameter stenosis, mean 26 10%). No patient had previous myocardial infarction, congestive heart failure, severe congenital or valvular heart disease, or documented cardiomyopathy. Patients with severe hypertension (systolic pressure 180 mm Hg and diastolic pressure 110 mm Hg), recent malignant ventricular arrhythmia, or conduction abnormalities were not considered for the study. All drug medications were stopped 48 hours before testing, except angiotensin-converting enzyme inhibitors and short-acting nitrates. Our institution’s human use committee approved the study, and all patients gave informed consent. According to predominant clinical symptoms, patients were classified into the following categories: chest pain during rest (n 18), chest pain during effort and rest (n 10), nocturnal chest pain (n 9), chest pain in the cold (n 19), and chest pain during stressful situations (n 44). The pretest probability of having coronary artery disease was 60 15%. In 84 patients, submaximal Bruce treadmill, exercise stress electrocardiographic testing was performed before diagnostic angiography; in 16 patients exercise testing was not performed because of poor patient motivation or physical inability to perform adequate exercise tests. No patient developed significant ST-segment changes during and after stress testing, defined as a decrease or increase in ST segment of 0.1 mV 0.08 second after the J point, or rhythm and conduction abnormalities. The ergonovine test was performed in consecutive patients at the end of diagnostic catheterization showing nonsignificant coronary artery stenosis and a normal left ventriculogram. All patients underwent selective coronary angiography using the Judkins technique, and multiple views of each coronary artery were obtained. Angiographic evaluation during ergonovine testing was performed in the view that best showed the coronary lesion. Doses of 0.05, 0.10, and 0.20 mg of ergonovine maleate (total cumulative dose 0.35 mg) were given intravenously in succession at 3-minute intervals, followed by intracoronary injection of nitroglycerin. Angiography was performed before the study, at the end of each stage, and after administration of nitroglycerin. Systemic blood pressure, electrocardiography, and echocardiography for wall motion changes were monitored continuously and recorded at the end of each stage. Electrocardiography was considered positive for myocardial ischemia when 0.1 mV elevation or depression of the ST segment was found 0.08 second after the J point. Coronary arteriographic images were digitized and analyzed (off-line) with the quantitative coronary angiography imaging system (Medis CMS software, version 1.11, Nuenen, The Netherlands) by an observer unaware of patient clinical data and echocardiographic results. After visual inspection of the coronary artery, the frame of optimal clarity in the end-diastolic part of From the University Institute for Cardiovascular Diseases, Department for Diagnostic and Catheterization Laboratories, Clinical Center of Serbia, Belgrade, Yugoslavia. Dr. Ostojic’s address is: University Institute for Cardiovascular Diseases, Department for Diagnostic and Catheterization Laboratories, Clinical Center of Serbia, 8 Koste Todorovica, Belgrade, Yugoslavia. E-mail: miodrag.ostojic@kcs.ac.yu. Manuscript received March 16, 2001; revised manuscript received and accepted July 3, 2001.

Low-dose adenosine stress echocardiography: Detection of myocardial viability

ObjectiveThe aim of this study was to evaluate the diagnostic potential of low-dose adenosine stress echocardiography in detection of myocardial viability.BackgroundVasodilation through low dose dipyridamole infusion may recruit contractile reserve by increasing coronary flow or by increasing levels of endogenous adenosine.MethodsForty-three patients with resting dyssynergy, due to previous myocardial infarction, underwent low-dose adenosine (80, 100, 110 mcg/kg/min in 3 minutes intervals) echocardiography test. Gold standard for myocardial viability was improvement in systolic thickening of dyssinergic segments of ≥ 1 grade at follow-up. Coronary angiography was done in 41 pts. Twenty-seven patients were revascularized and 16 were medically treated. Echocardiographic follow up data (12 ± 2 months) were available in 24 revascularized patients.ResultsWall motion score index improved from rest 1.55 ± 0.30 to 1.33 ± 0.26 at low-dose adenosine (p < 0.001). Of the 257 segments with baseline dyssynergy, adenosine echocardiography identified 122 segments as positive for viability, and 135 as necrotic since no improvement of systolic thickening was observed. Follow-up wall motion score index was 1.31 ± 0.30 (p < 0.001 vs. rest). The sensitivity of adenosine echo test for identification of viable segments was 87%, while specificity was 95%, and diagnostic accuracy 90%. Positive and negative predictive values were 97% and 80%, respectively.ConclusionLow-dose adenosine stress echocardiography test has high diagnostic potential for detection of myocardial viability in the group of patients with left ventricle dysfunction due to previous myocardial infarction. Low dose adenosine stress echocardiography may be adequate alternative to low-dose dobutamine test for evaluation of myocardial viability.

Comparative utility of gated myocardial perfusion imaging and transthoracic coronary flow reserve for the assessment of coronary artery disease in patients with left bundle branch block.

ObjectivesTo compare the diagnostic utility of gated single-photon emission computed tomography (SPECT) methoxy isobutyl isonitrile (MIBI) myocardial perfusion imaging and transthoracic Doppler echocardiography (TTDE) coronary flow reserve (CFR) to coronary angiography for detecting coronary artery disease (CAD) in patients with left bundle branch block (LBBB). MethodForty-three patients with complete LBBB and an intermediate pretest probability for CAD underwent dipyridamole stress TTDE and gated SPECT MIBI during the same session and coronary angiography within a month. The parameters of myocardial perfusion (summed stress score, summed difference scores) regional wall function (wall motion score, wall thickening score) and ejection fraction were derived using the 17-segment model and 4D-MSPECT software. TTDE variables included peak flow velocity at rest and during hyperemia in left anterior descending artery (LAD), based on which CFR was calculated (normal>2). ResultsPerfusion ischemic scores were significantly higher in group 1 with angiographic evidence of greater than 50% LAD stenosis compared with group 2 with less than 50% LAD stenosis (summed stress score 12.4±5.5 vs. 8.3±3.5, P<0.05, summed difference score 3.7±1.2 vs. 1.1±0.3, P<0.01, respectively). Left ventricular regional wall function and ejection fraction were not different between the two groups. CFR was significantly lower in group 1 than in group 2 (1.65±0.21 vs. 2.31±0.28, P<0.001). Gated SPECT MIBI and CFR had similar sensitivity (88 vs. 88%), specificity (80 vs. 84%), and accuracy (84 vs. 86%) for detecting CAD in patients with LBBB. The agreement between the two methods was 85%. ConclusionOur results show comparable diagnostic utility and high agreement between gated SPECT MIBI perfusion imaging and TTDE CFR assessment for detecting CAD in patients with LBBB. The advantage of gated SPECT MIBI over TTDE CFR measurements is the ability to assess the perfusion abnormalities in multiple vascular territories during the same procedure, which is convenient for detecting multi-vessel disease in patients with LBBB.

Site of myocardial infarction and severity of perfusion abnormalities impact on post-stress left ventricular function in patients with single-vessel disease: gated single-photon emission computed tomography methoxyisobutylisonitrile study.

ObjectivesWe used gated single-photon emission computed tomography methoxyisobutylisonitrile (SPECT MIBI) to (i) determine whether location of myocardial infarction (MI) and severity of perfusion abnormalities affect post-stress left ventricular function in patients with single-vessel coronary artery disease, and (ii) correlate changes between post-stress and rest ejection fraction (EF) with the severity of perfusion and regional wall motion abnormalities (RWMAs). MethodsEighty-eight patients with a history (≥3 months) of anterior MI (n=45) or inferior MI (n=43) underwent a 2-day stress–rest gated SPECT MIBI. 4D-MSPECT software was used to calculate left ventricular end-diastolic volume (EDV), end-systolic volume (ESV), EF, and the difference from post-stress to rest EF (EFs–EFr). Summed stress scores, summed rest scores, and summed difference scores (SDS) were calculated based on the 17-segment model. RWMAs were visually assessed using a 5-point score. ResultsPatients with anterior MI, compared with those with inferior MI, showed significantly greater perfusion abnormalities (summed stress score 11.0±5.5 vs. 7.5±2.4, P<0.01, summed rest score 7.4±4.7 vs. 5.2±1.9, P<0.01, SDS 3.3±1.0 vs. 1.9±1.0, P<0.05) and higher post-stress and rest RWMA (RWMSS 12.2±6.0 vs. 8.7±4.1, P<0.01, RWMRS 8.7±5.4 vs. 5.6±3.0, P<0.01). In 22 patients with anterior reversible ischemia in addition to fixed defect, post-stress and rest EDV and ESV were significantly larger and post-stress EF decreased more than in 21 patients with inferior MI (EDV 144.0±28.9 ml vs. 108.6±36.9 ml, ESV 70.6±22.2 ml vs. 53.4±20.5 ml, EFs–EFr −4.2±3.5% vs. −1.5±2.2%, P<0.01). SDS and RWMA were highly correlated with EFs–EFr. ConclusionIn patients with single-vessel coronary artery disease, the extent and severity of perfusion and RWMAs assessed by gated SPECT MIBI are greater after anterior MI than inferior MI. Global left ventricular function is significantly more affected after anterior MI only in patients with reversible ischemia in addition to fixed wall defect. Decrease in EF from post-stress to rest is closely associated with the severity of perfusion and RWMAs. Overall results suggest that the extent and severity of perfusion and RWMAs are more prominent in the myocardial region supplied by left anterior descending coronary artery than by right coronary artery, which may explain significantly worse post-stress left ventricular function after anterior MI.