Short-term reproducibility of dipyridamole-echocardiography test

Overall and Segmental Agreement of Stress Echocardiography

Several stress echocardiography (SE) modalities have been introduced for diagnosing coronary artery disease (CAD). Exercise and dobutamine SE are commonly considered to have a better diagnostic accuracy than vasodilator SE. The purpose of this study was to assess the agreement between the test results and the segmental concordance between three SE tests in patients with chest pain. A total of 60 patients (mean age, 55.1 years; SD, 2.1) were tested by symptom-limited bicycle (BSE), dipyridamole-atropine (DiASE), and dobutamine (DSE) tests. CAD (50% stenosis) was present in 44 patients, and 26 patients had one-vessel disease. In BSE and DSE, the double product at peak stress (26.5 and 16.1 vs 13.3 x 10(3), respectively, P < 0.005 vs DiASE) and the peak wall motion score index were higher than in DiASE (1.40 and 1.35 vs 1.26, respectively, P < 0.05 vs DiASE). BSE, DiASE, and DSE did not differ in sensitivity in diagnosing CAD (90%, 93%, and 95%, respectively). Similarly, there were no statistically significant differences in the diagnostic accuracy of BSE, DiASE, and DSE (78%, 88%, and 87%, respectively). The intermethod agreement was moderate between BSE and DiASE (kappa = 0.51), good between BSE and DSE (kappa = 0.62), and moderate between DiASE and DSE (kappa = 0.57). The segmental agreement between BSE, DiASE, and DSE was mostly moderate. Agreement was best between the pharmacologic tests due to test protocols, especially the anterior wall (kappa > 0.60). Also, the basal segments showed good agreement. In conclusion, BSE, DiASE, and DSE have a similar diagnostic accuracy in detecting CAD. The overall agreement between the tests was good, and the assessment of wall motion was variable. Nevertheless, concordant diagnosis of a patient can be obtained by BSE, DiASE, and DSE without loss of diagnostic power.

Pharmacological preconditioning of ischemic heart disease by low-dose dipyridamole

Fourteen patients affected with coronary artery disease underwent two consecutive dipyridamole echocardiographic stress tests, in basal conditions and after repeated low doses of intravenous dipyridamole, following the observation that pulse increases in adenosine plasma levels due to repeated intravenous administration of dipyridamole mimic the mechanism of ischemic preconditioning. Echocardiographic, electrocardiographic, haemodynamic parameters, and adenosine plasma levels were measured. After the second test, six patients were completely negative, and in those eight still positive the onset of dyssynergy was delayed.

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

BACKGROUND

Exercise and pharmacological stress echocardiography 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 RESULTS

We performed exercise (maximal treadmill Bruce protocol), dobutamine (up to 40 micrograms/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 > or = 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 beta-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 beta-blockers (84%) than in the patients receiving beta-blocker therapy (66%), whereas the accuracy of exercise and dobutamine were only slightly higher in the patients not receiving beta-blockers. Significant side effects occurred in 3%, 11%, and 1% of patients during exercise, dobutamine, and dipyridamole tests, respectively.

CONCLUSIONS

Despite 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 beta-blocker therapy significantly decreased the accuracy of the dipyridamole stress echocardiography test. Pharmacological stress testing (dipyridamole without beta-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.

Diagnostic and prognostic value of dipyridamole echocardiography in patients with suspected coronary artery disease. Comparison with exercise electrocardiography

BACKGROUND

Before any new diagnostic test is accepted in clinical practice, such a test should be compared with established diagnostic tools in an appropriately large series of patients encompassing the complete spectrum of challenges to which the test is exposed. The aim of the present study was to assess the relative diagnostic and prognostic accuracies of high-dose dipyridamole echocardiography (two-dimensional echocardiographic monitoring during dipyridamole infusion up to 0.84 mg/kg over 10 hours) versus maximal symptom-limited bicycle exercise ECG test in patients with angina.

METHODS AND RESULTS

We studied 429 consecutive in-hospital patients who met the following inclusion criteria: history of chest pain, off antianginal therapy for at least 2 days (1 week for beta-blockers), no previous myocardial infarction and/or obvious regional left ventricular dyssynergy of contraction (akinesis or dyskinesis) at baseline, and acceptable acoustic window under resting conditions. All patients underwent dipyridamole echocardiography and exercise ECG--on different days and in random order--within 1 week of coronary angiography (which was performed independent of test results) and were followed up for 37.8 +/- 14 months (range, 1 to 73 months). Criteria of positivity were for dipyridamole echocardiography, a transient regional dyssynergy absent in the baseline examination; for exercise ECG, an ST-segment shift of > or = 0.1 mV from baseline; and for coronary angiography, a luminal reduction of > or = 75% in at least one major coronary vessel (50% for left main). There were 183 patients without and 246 with coronary artery disease; 132 had one-, 70 had two-, and 44 had three- and/or left main vessel disease. The specificity was higher for dipyridamole echocardiography than for exercise ECG (90% versus 51%, P < .001). The overall sensitivity of dipyridamole echocardiography was similar to that of exercise ECG (75% versus 74%, P = NS), with no significant differences in the subset with one- (67% versus 69%, P = NS), two- (79% versus 77%, P = NS), or three- (93% versus 86%, P = NS) vessel disease. During the follow-up, there were 20 deaths, 13 nonfatal myocardial infarctions, and 126 revascularization procedures. In the univariate analysis, dipyridamole resulted in higher chi 2 values than did exercise stress testing. A Cox forward stepwise survival analysis identified the dipyridamole time as the most powerful prognostic predictor of death (chi 2 = 19.4, P < .0001) of all invasive and noninvasive parameters. The dipyridamole time also provided independent and additional prognostic information when it was adjusted for age, diabetes, resting ECG, and exercise stress test according to a modified, interactive stepwise procedure. This is true when death only, death and myocardial infarction, and death, myocardial infarction, and revascularization procedures were considered end points.

CONCLUSIONS

In patients with no previous myocardial infarction and good resting left ventricular function, compared with exercise ECG, dipyridamole echocardiography has a similar sensitivity and a higher specificity for the noninvasive detection of angiographically assessed coronary artery disease. Dipyridamole echocardiography also provides information in addition to that provided by exercise ECG for predicting death, infarction, and all events when the presence as well as the timing, severity, and extension of dipyridamole-induced wall motion abnormalities are considered.

Dipyridamole-echocardiography: clinical usefulness following interventions

Dipyridamole-echocardiography test response can be expressed not only in a black or white (positive vs negative) code but also, in positive tests, by a gray scale integrating the severity and extent of the dyssynergy as well as the ischemia-free stress time. The recognition of the dyssynergy is important to establish the diagnosis; however, the evaluation of the degree of the induced ischemia, stratified according to spatiotemporal coordinates, is even more important because it accurately predicts the coronary anatomical and functional situation, as well as the prognosis of the individual patient. Furthermore, the "shades of gray" in a positive response have proved useful in assessing the beneficial effects of several interventions: coronary angioplasty; coronary artery bypass surgery; thrombolysis; and medical antianginal therapy. Due to its excellent reproducibility, dipyridamole-echocardiography can play a pivotal role for simple, safe, fast, accurate, and objective assessment of therapeutic interventions, either mechanical or pharmacological, based upon the presence, timing, severity, and extent of dipyridamole-induced dyssynergy.

Usefulness of high-dose dipyridamole echocardiography test in coronary angioplasty

Seventy-four consecutive patients with angina undergoing single-lesion percutaneous transluminal coronary angioplasty were evaluated with high-dose (up to 0.84 mg/kg during 10 minutes) dipyridamole echocardiography test (DET) before angioplasty and when possible, afterward. Angioplasty was clinically or angiographically successful in 63 patients and unsuccessful in 11. Before the procedure, 69 patients had a positive DET. Of these 69 patients, six with clinicall unsuccessful angioplasty had a dipyridamole time (i.e., the time from the onset of dipyridamole infusion to development of asynergy) lower than the 63 patients with clinically successfully angioplasty (4.2 +/- 2.9 vs. 7.0 +/- 2.9 minutes, mean +/- SD, p less than 0.01). In the five patients with angiographically unsuccessful angioplasty (residual stenosis diameter, greater than 50%), coronary stenosis decreased from 89 +/- 10 to 69 +/- 22 (p = NS); DET was positive in all five before and in four of the five after the procedure (100% vs. 80%, p = NS). In the 63 patients with angiographically successful angioplasty, coronary stenosis diameter was reduced from 85 +/- 9% to 30 +/- 10% (p less than 0.01). DET was positive in 58 patients before and in only 16 after the procedure (92% vs. 25%, p less than 0.01). In the 16 patients with positive DET, before and after angioplasty, dipyridamole time increased from 5.6 +/- 2.2 before to 7.3 +/- 2.4 minutes immediately after the procedure (p less than 0.05). After an average follow-up time of 10.8 +/- 5.9 months, angina recurred in eight of 47 patients with negative DET after angioplasty and in 11 of 16 patients with positive DET (17% vs. 69%, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)