Enrico Magagnini

Incremental diagnostic value of dobutamine stress echocardiography and dobutamine scintigraphy (technetium 99m-labeled sestamibi single-photon emission computed tomography) for assessment of presence and extent of coronary artery disease

BackgroundThe incremental diagnostic value of dobutamine stress echocardiography (DSE) and 99mTc-labeled sestamibi single-photon emission computed tomography for the evaluation of the presence and extent of coronary artery disease (CAD) was assessed with ordered logistic regression and receiver-operating characteristic curves.Methods and ResultsForty-five consecutive patients (33 men and 12 women; 53±6.8 years) underwent exercise electrocardiography and simultaneous DSE and sestamibi single-photon emission computed tomographic imaging. Coronary angiography was performed in all patients (significant coronary stenosis >50%). On the basis of the results of exercise electrocardiography, the pretest probability for CAD (Diamonds algorithm) was low (45.6%±12.7%). According to ordered logistic regression analysis, some models were estimated that performed a diagnostic accuracy level for CAD. In particular, we evaluated a clinical model (model 1) determined by the following parameters: sex, age, presence of chest pain, and positivity of electrocardiogram during dobutamine stress test. This model was 64.3%±10.7% accurate for the prediction of CAD. The addition to model 1 of DSE parameters (wall motion stress and rest score index and relative difference) (model 2) yielded a diagnostic accuracy of 81.4%±4.3% (p<0.045), whereas the addition to model 1 of single-photon emission computed tomographic parameters (the difference between perfusional stress and rest score index) (model 3) improved diagnostic accuracy to 92.3%±5.5% (p<0.003), a level that appeared significantly higher than that of model 2 (p<0.016).ConclusionBoth noninvasive methods for the detection of CAD showed a good diagnostic accuracy, especially when test-derived parameters were combined with clinical data. Nevertheless, the single-photon emission computed tomographic model showed a higher sensitivity compared with the DSE model.

Renal effects of cardiac angiography with different low-osmolar contrast media.

The aim of this study was to evaluate the renal effects of cardiac angiography performed with three low-osmolar contrast media (CM): iopromide (IPR), ioversol (IVR) and ioxaglate (IOX). IPR and IVR are non-ionic CM, IOX is an ionic CM. Different parameters of renal function were determined before and 6, 24, 48, 72 hrs after angiography in 45 patients: 15 patients were examined with IPR, 15 with IVR and 15 with IOX. Glomerular effects – Plasma creatinine increased slightly at the 24th hour after IVR and IOX and at 48 hours after IOP. A significant increase in plasma β2-microglobulin was observed, at the same time, only after IOX. A significant decrease in creatinine clearance was found at 6 hours after IOX. No significant variations in glomerular filtration rate (GFR) and in effective renal plasma flow were found at 48 hours after cardiac angiography; while filtration fraction was significantly reduced after IOP and IOX. Tubular effects – A marked decrease in sodium clearance and a relevant increase of urinary activities of different tubular enzymes were found after cardiac angiography with all CM, but were more evident after the ionic CM IOX, than after the two non-ionic agents. These tubular effects reached the maximum between 6 and 24 hours and returned to baseline within 72 hrs after cardiac angiography. In conclusion, slight glomerular effects were observed mainly after IOX. A reversible tubular malfunction was found with the three low-osmolar CM and was more evident after ionic CM IOX, thus suggesting that other mechanisms, besides osmolarity, play a role in tubular toxicity due to CM. In no patient did the glomerular and tubular effects of CM have a clinical relevance.

Simultaneous dobutamine stress echocardiography and dobutamine scintigraphy (99mTc-MIBI-SPET)for assessment of coronary artery disease

AbstractBackground: Simultaneous dobutamine stress echocardiography (DSE) and99mTc-MIBI-SPET (DMS) for the evaluation of the presence and the extent of coronary artery disease (CAD) were assessed for a head to head comparison regarding the diagnostic accuracy of the two tests. Methods and Results: Forty-five consecutive patients (33 males and 12 females: 53±6.8 yr.) underwent exercise electrocardiography and simultaneous dobutamine stress echocardiography and MIBI-SPET imaging. Coronary angiography was performed in all patients (significant coronary stenosis > 50%). On the basis of the results of exercise electrocardiogram the pre-test probability for coronary artery disease (Diamonds algorithm) was low (45.6±12.7 %). The overall specificity, sensitivity and predictive accuracy of Echo-dobutamine stress test for diagnosis of the presence or absence of CAD were: specificity 82%, sensitivity 76%, diagnostic accuracy 80%, positive predictive value 90%, negative predictive value 40%. The overall specificity, sensitivity and predictive accuracy of MIBI-SPET-dobutamine test for diagnosis of the presence or absence of CAD were: specificity 86%, sensitivity 87%, diagnostic accuracy 84%, positive predictive value 97%, negative predictive value 54%. MIBI-SPET-dobutamine test showed a significantly higher sensitivity in comparison with ECHO-dobutamine test (P<0.05). Conclusion: Both noninvasive methods for the detection of CAD showed a good diagnostic accuracy. Nevertheless the SPET model showed an higher sensitivity in comparison with DSE model, essentially in the presence of a lower extent of CAD and during submaximal test.

Incremental diagnostic value of dipyridamole echocardiography and exercise thallium 201 scintigraphy in the assessment of presence and extent of coronary artery disease

BackgroundThe incremental diagnostic information of two noninvasive tests for the detection of coronary artery disease (CAD), dipyridamole echocardiography, and exercise201Tl myocardial scintigraphy was assessed in a series of 102 patients with ordered logistic regression and receiver-operating characteristic curves.Methods and ResultsPatients were selected from those referred to our cardiovascular centers with the clinical suspicion of CAD. After clinical evaluation, all patients underwent both noninvasive tests during hospitalization 2 weeks before coronary arteriography. The coronary arteriogram was used as a gold standard: CAD was defined as the presence of one or more vessels with 50% or greater narrowing of the luminal diameter. Clinical data were 73.0%±5.7% accurate in the prediction of CAD. The addition of dipyridamole echocardiographic data to the clinical model yielded a diagnostic accuracy of 88.3%±4.3% (p<0.00001), whereas the addition of thallium scintigraphic parameters to the clinical model improved diagnostic accuracy to 93.8%±2.6% (p<0.00001). A significant increase in accuracy to 97.2%±1.4% was achieved when thallium scintigraphic data were added to the clinical and dipyridamole-echocardiographic model (p<0.00001).ConclusionBoth noninvasive methods for detection of CAD, DET, and ETS showed a good diagnostic accuracy especially when tests-derived parameters were combined with clinical data by means of relative logistic models; nevertheless the ETS model showed a higher sensitivity in comparison with the DET model, essentially in presence of a lower extent of CAD.