Electron and electrospray ionization mass spectrometry in the characterization of some 1-allyl-3-phenylaziridines

A series of cis- and trans-isomeric aziridines has been studied under electron impact (EI) and electrospray ionization (ESI) conditions. The fragmentation patterns of the examined compounds have been elucidated by means of sequential product ion fragmentation experiments (MS(n)) performed using an ion trap mass spectrometer. Particular attention has been paid to isomer characterization in these precursors of azetidinones, that in turn are precursors of new beta-lactam antibiotics.

Electrospray mass spectrometry of a series of mixed nitrido 99gTc- heterocomplexes conjugated with bioactive molecules

Electrospray ionization mass spectrometry (ESI-MS) was successfully employed for the identification of six nitrido technetium mixed ligand complexes with a general formula of [99gTc(N)(O,S-BID)(PNP)], where PNP represents a heterodiphosphine and O,S-BID represents a simple dianionic bidentate ligand (compounds 1-3) or a more sophisticated N-substituted O,S-cysteine framework conjugated with a bio- active molecule (BAM) (compounds 4-6). In spite of similar coordination spheres exhibited by all the complexes investigated, simple co-ordination compounds 1-3 displayed collisionally-induced fragmentation processes (MSn) different from those observed in biomolecule-containing compounds 4-6. In the latter, more decomposition channels were observed. This behavior is likely to be associated with some additional intramolecular contacts of the biomolecule (or part of the biomolecule) with pendant group(s) incorporated in the PNP-co-ligand. This view is further supported by the observations arising from both in vitro binding affinity experiments and nuclear magnetic resonance investigations. The presence of cationized forms for all compounds 1-6 and the practical lack of the [2M + Na]+ species for biomolecule-containing compounds 4-6 provided further evidence of a subtly different structural conformation.

Electrospray ionization mass spectrometry in the structural characterization of some diphenyllead(IV) thiosemicarbazonates

The behavior in electrospray ionization mass spectrometry (ESI-MS) conditions of some complexes formed by Pb(C6H5)2(OAc)2 with salicylaldehyde, 2-ketobutyric acid, pyridine-2-carbaldehyde, 2-acetylpyridine, and 2-benzoylpyridine thiosemicarbazones, was studied in detail with the aid of collisional experiments performed by ion trap. The homoleptic complexes of tridentate thiosemicarbazonate dianions (TSC2-) lose the phenyl groups first, destabilizing the high oxidation state of the metal and leading to Pb(II) complexes in which the TSC2- ligand or a part of it remains coordinated to the metal. The main difference among the complexes derives from the presence of a carboxylate group on the 2-ketobutyric acid thiosemicarbazonato ligand, which probably interacts with a Na+ cation leading to ESI-generated [M+Na]+ species. In the absence of the carboxylate group, the production of abundant protonated molecules is observed. These different behaviors have been rationalized from the structural point of view. The heteroleptic mononuclear complexes, including thiosemicarbazonate and AcO- monoanions in the coordination sphere, do not yield intact ionized molecular species, and the most abundant ESI-generated ion is due to AcO- loss. The spectrum of the binuclear heteroleptic complex formed by the salicylaldehyde thiosemicarbazonate monoanion is conditioned by the weak bonding interaction displayed by the acetate bridge. MSn experiments yield important information on the relative ligand-Pb bond strengths. This work forms part of the search for chelating agents that can be used for effective chemotherapy of organolead poisoning.

Is the atmospheric pressure chemical ionisation and collisionally induced methanol loss from protonated dehydroamino acids a retrosynthetic process?

Unsaturated 5(4H)-oxazolones lead, by methanolysis, to the corresponding dehydroamino acid derivatives. Interestingly, under atmospheric pressure chemical ionisation (APCI) conditions, the latter give rise, aside from abundant [M+H](+) ions, to [MHbondCH(3)OH](+) species, formally corresponding to the protonated oxazolones employed for their synthesis. Retrosynthetic processes have often been described as energetically favoured decompositions of odd-electron molecular ions but never invoked in APCI-activated fragmentations. To investigate this possible retrosynthetic process, occurring also under collisional conditions, some experiments on the deuterated analogues have been undertaken. The breakdown curves of [M+H](+) of oxazolones and [MHbondCH(3)OH](+) of the dehydroamino acid derivatives are superimposable, proving their structural identity and giving experimental evidence of the occurrence of a real retrosynthetic process from even-electron protonated molecules.

Atmospheric pressure photoionization mechanisms. 2. The case of benzene and toluene

Benzene and toluene have been proposed previously as dopants in atmospheric pressure photoionization (APPI) experiments on compounds exhibiting ionization energies higher than the energy of photons used for irradiation. Their low ionization energies lead to their easy photoionization and the ions so formed lead to the ionization of analytes through charge exchange. However, some measurements have shown that some protonation reactions also take place, and a series of experiments was undertaken to investigate this unexpected behavior. It was shown that, when benzene is irradiated in the APPI source, the odd-electron molecular ions of phenol, diphenyl ether and phenoxyphenol are produced in high yield, together with protonated diphenyl ether and protonated phenoxyphenol. These results have been confirmed by deuterium labelling and MS(n) experiments. A possible mechanism is proposed, based on a radical attack by benzene molecular ions on oxygen molecules present inside the APPI source, analogous to that proposed in the literature for phenyl radicals. Similar results have been obtained with toluene, proving that APPI is able to activate a series of reactions leading to highly reactive species which are highly effective in promoting ionization of molecules with ionization energies higher than the photon energy.

The mass spectrometric behaviour of fluorinated ephedrines under different protonating conditions

The behaviour of di- and tri-fluorinated-ephedrines and -norephedrines has been studied by fast atom bombardment, atmospheric pressure chemical ionisation (APCI) and electrospray ionisation (ESI) experiments and compared with that of the unfluorinated analogues. Under all the employed ionisation conditions [MH](+) and [MH-H(2)O](+) species are mainly produced. Both high- and low-energy collisional experiments were performed on the protonated molecules to put in evidence any possible significant differences due to different ionisation methods. Multiple MS/MS experiments, performed by ion trap, allowed establishment of the decomposition pathways at lower activation energy. The data thus obtained indicate that the presence of fluorinated substituents leads to a higher stability of the molecular species, with strengthening of the C(1)-C(2) bond of the molecule and with a lower proclivity to thermally-induced dehydration.

Electrospray ionization mass spectrometry in studies of aluminium(III)-ligand solution equilibria

Electrospray ionization mass spectrometry (ESI-MS) has been applied to the study of solution equilibria between Al(III) and the two ligands 4-hydroxy-3-pyridinecarboxylic acid (4H3P) and 3-hydroxy-4-pyridinecarboxylic acid (3H4P). The results compare well with the speciation data obtained from potentiometric, UV-visible spectroscopy, and NMR measurements. This agreement suggests the applicability of ES-MS to the study of more complicated aluminium-ligand systems.

Surface-activated no-discharge atmospheric pressure chemical ionization

A new ionization method named surface-activated chemical ionization (SACI) has been realized. In this invention a commercially available atmospheric pressure chemical ionization (APCI) chamber, employed without any corona discharge (no-discharge APCI), has been modified with the insertion of a gold surface, leading to a significant improvement in the ionization efficiency. The ionization of the sample takes place by both gas-phase and surface-activated processes. This new ionization source is able to generate ions with high molecular mass and low charge states, leading to improved sensitivity and reduced noise. The new device has been tested in the analysis of some peptides. A comparison between the performance with and without the presence of the surface, and the optimization of the operating conditions (nebulizing gas flow, sample solution flow, pH of solution, and surface area), are reported and discussed.

Synthesis and physicochemical characteristics of a liver-targeted conjugate of fluorodeoxyuridine monophosphate with lactosaminated human albumin

In previous experiments fluorodeoxyuridine monophosphate (FUdRMP) was conjugated with lactosaminated human albumin (L-HSA). Fluorodeoxyuridine (FUdR) is an anticancer agent and L-HSA is a hepatotropic carrier of drugs obtained by the covalent linkage of lactose residues to the albumin molecule. The conjugate was synthesised via the imidazolide of FUdRMP at alkaline pH. Peripheral venous administration of L-HSA-FUdRMP produced enhanced FUdR levels in hepatic blood and might accomplish a non-invasive loco-regional chemotherapy of liver micrometastases. In the present paper some physicochemical characteristics of L-HSA-FUdRMP are reported. Polyacrylamide gel electrophoresis indicated that the coupling reaction did not cause covalent aggregation of the L-HSA molecules. 31P NMR spectra of the conjugate showed that FUdRMP was linked to L-HSA by phosphoamide bonds to lysine and histidine residues, and the area of the peak due to the lysine bond represented more than 80% of the spectrum of L-HSA-FUdRMP. MALDI analysis revealed a partial degradation of the peptide backbone of the conjugate which could not be detected using other methods of analysis. The degradation was not caused by the coupling of lactose molecules to albumin, but rather a consequence of FUdRMP conjugation with L-HSA. This fragmentation was dependent on the pH of the medium used for the FUdRMP coupling reaction. By decreasing the pH to 7.5, conjugates were obtained with a lower drug load but with a substantially reduced fragmentation, which should be preferred for a clinical use of L-HSA-FUdRMP.

[Reporting echocardiography exams with the G8-Cardio ANMCO software]

BACKGROUND

The availability of a common computerized program for echocardiographic study archiving and reporting at national and/or international level could make it possible to standardize the echo reports of different echocardiographic laboratories, and to use the wealth of data thus obtainable with echocardiography, and to exploit its capillary territorial distribution, with the aim of collecting echocardiographic data in a standard format for epidemiological, scientific and administrative purposes.

METHODS

To develop such a software, an ad hoc joint National Association of Hospital Cardiologists and Italian Society of Echocardiography task force worked in conjunction with the Italian Branch of Agilent Technologies to standardize the phraseology of accepted echocardiographic terms and of the quantitative parameters derived from transthoracic and transesophageal echocardiographic examination at rest as well as during exercise and pharmacological stress, and to develop an ad hoc software. This echocardiographic study archiving and reporting program is part of the whole G8-Cardio ANMCO software developed to computerize the whole cardiological chart. The software has been developed by Agilent Technologies to provide a fast, easy-access and easy to use report generator for the non-computer specialist using DBMS Oracle 7.3 database and Power Builder 5.0 to develop a user-friendly interface.

RESULTS

The number of qualitative and quantitative variables contained in the program is 733 for echocardiography at rest, while it depends on the stressor and on the length of the examination for the stress echo (dipyridamole 214-384, dobutamine 236-406, exercise 198-392). The program was tested and refined in our laboratory between November 1999 and May 2000. During this time period, 291 resting and 56 stress echocardiographic studies were reported and recorded in a database. On average, each resting echocardiographic study lasting 10 +/- 4 (range 5-17) min was recorded using 50 +/- 11 (range 33-67) variables and 41,566 bytes of hard-disk memory space. Stress echocardiographic studies, each lasting 7 +/- 5 (range 5-21) min, were recorded using 143 +/- 74 (range 38-194) variables and 38,531 bytes of hard-disk memory space.

CONCLUSIONS

To our knowledge this software represents the first experience of a common computerized program for echo archiving and reporting carried out at national level.

[The role of biochemical markers of myocardial damage in clinical practice: the diagnosis of infarct and risk stratification. The Intersociety Interdisciplinary Study Group of the ANMCO-SIBioC-SIMeL, Markers of Muocardial Lesions. L'Associazione Nazionale Medici Cardiologi Ospedalieri-Società Italiana di Biochimica Clinica-Società Italiana di Medicina di Laboratorio]

For many years creatine kinase (CK) and CK-MB isoenzymes were used together with the ECG to confirm the presence of myocardial infarction. During the last decade newer cardiac markers have been introduced and immunological test systems developed for their quantification. Among these new markers, a prominent role has emerged for cardiac troponins (T or I). These technological advanced assays have shown greater sensitivity compared to "conventional cardiac enzymes;, thereby identifying patients with small--at times, microscopic--infarcts who would not have met defining criteria for myocardial infarction in an earlier era. Another major advantage shown by both cardiac troponins with respect to "conventional cardiac enzymes" is their ability to predict clinical outcome over a short- or long-term follow-up in patients with acute coronary syndromes, and this appears to be particularly relevant in patients with micronecrosis, who constitute a high-risk subgroup of unstable angina patients. Recently, myoglobin has also been widely applied as a marker. Although lacking in myocardial specificity, it is the earliest marker to show an increase after coronary occlusion. Thus, the combined use of myoglobin and a cardiospecific structural protein such as troponin T or I may prove an attractive strategy for biochemical testing in chest pain patients. With the routine use of these novel cardiac markers, fascinating opportunities are now open in the field of diagnostic classification (making the World Health Organization definition of myocardial infarction obsolete) and risk stratification in chest pain patients; opportunities that were unforeseen in the era of cardiac enzymes. However, the use of these markers has also posed some important questions on: a) the best and most cost-effective diagnostic strategy in chest pain patients; b) the remaining role of cardiac enzymes; c) the therapeutic consequences of a positive test result.

[Atherosclerosis and simvastatin: new questions for the new millennium]

Coronary artery disease is still associated with high morbidity and mortality in Western countries. Lipid blood levels have a tight correlation with the risk of coronary events, and the results of many trials on lipid-lowering therapy (and particularly on simvastatin) demonstrated a significant reduction in total and cardiac mortality, and in the incidence of myocardial infarction and coronary events; even the progression of coronary stenosis has been reduced by treatment with statins. Beyond cholesterol reduction, simvastatin exerts many favorable effects on endothelial function, inflammatory activity, expression of pro-thrombotic factors and oxidative stress, yielding a rational basis for its important clinical positive effects, both in primary and secondary prevention of coronary disease. Future developments, which are the subjects of many planned or ongoing clinical trials, are related to the treatment of high-risk patients, the evaluation of the efficacy of elevated simvastatin dosages and of a deep reduction in cholesterol blood levels, the interaction between simvastatin and other drugs (antioxidant compounds, vitamins, antiplatelet drugs) or interventional procedures (percutaneous transluminal coronary angioplasty). Particularly, the Heart Protection Study, the A to Z trial, and the SEARCH and SMART studies will provide important data on a wider, earlier and greater use of simvastatin, which has been demonstrated effective both in the prevention and treatment of acute coronary syndromes.

The effect of verapamil on left ventricular remodelling and diastolic function after acute myocardial infarction (the Verapamil Infarction Study on Remodelling and Relaxation--VISOR)

The VISOR is a double blind, randomized, placebo-controlled study aimed to assess the effects of early and prolonged administration of verapamil on the left ventricular geometry and diastolic function in patients with anterior acute myocardial infarction treated with thrombolysis. Patients with heart failure or ejection fraction < 45% were excluded. Within 12 hours from starting thrombolysis, 70 patients were given verapamil (5 mg/hour intravenously for the first 24 hours, followed by 120 mg t.i.d. perorally for 6 months) or equivalent placebo. Echocardiograms were performed on admittance, before discharge, after 3 months and 6 months. The following parameters were calculated: left ventricular volumes, ejection fraction, sphericity index, early (E) and late (A) transmitral peak flow velocities and time-velocity integrals with their ratios, deceleration time and half-time of E, isovolumic relaxation time (IVRT), and non-invasive time constant of ventricular relaxation (tau). The basal and the last available parameters were considered for statistical analysis. The effects of the treatment on the left ventricular volumes, ejection fraction, and sphericity index were not statistically relevant. Conversely, a reduction of E/A ratio (P < .05) and increases of A integral (P < .01), deceleration time and half-time of E, IVRT and tau (P < .05) were found in the placebo group and not in the verapamil group. No significant changes in the blood pressure, heart rate, PQ interval, and biochemical parameters were observed in the two groups. In conclusion, in patients with a thrombolysed anterior acute myocardial infarction and preserved systolic function, verapamil can prevent alterations of the diastolic function in absence of effect on ventricular remodelling, and has a good safety profile.

Prothrombotic genetic risk factors in young survivors of myocardial infarction

It has long been thought that an individual thrombotic tendency increases the risk of myocardial infarction, especially in young adults. Several "prothrombotic" genetic factors that may influence the individual thrombotic risk have been identified. To investigate the association between the risk of myocardial infarction at a young age and genetic factors thought to be associated with an increased tendency to thrombosis (the polymorphisms 4G/5G of the PAI-1 gene, PIA1/PIA2 of the platelet glycoprotein IIIa, C3550T of the platelet glycoprotein Ib gene, G10976A of the factor VII gene, C677T of the methylenetetrahydrofolate reductase gene, G1691A of the factor V gene, and G20210A of the prothrombin gene), we performed a case-control study evaluating 200 survivors (185 men, 15 women) of myocardial infarction who had experienced the event before the age of 45 years and 200 healthy subjects with a negative exercise test, individually matched for sex, age, and geographic origin with the cases. The presence of the PIA2 polymorphic allele was the only prothrombotic genetic factor associated with the risk of myocardial infarction at a young age. The odds ratio for carriers of the PIA2 allele compared with those of the PIA1 allele was 1.84 (95% confidence intervals (CI) 1.12 to 3.03). There was a significant interaction between the presence of the PIA2 allele and smoking: with their simultaneous presence, 46% (95% confidence intervals 11% to 81%) of premature myocardial infarctions were attributable to the interaction between the two factors. In conclusion, carrying the PIA2 polymorphic allele of platelet glycoprotein IIIa was the only genetic prothrombotic factor associated with the risk of developing myocardial infarction at a young age. The clinical expression of this genetic predisposition seems to be enhanced by smoking.

Gallopamil activity on asynergic viable myocardium in acute myocardial infarction: insights on stunned and hibernating myocardium

The influence of the calcium antagonist gallopamil on the contractility of asynergic viable myocardium after acute myocardial infarction treated with thrombolysis was investigated by two-dimensional echocardiography. Sixteen patients with > or = 1 viable segment(s), identified during the low-dose phase (up to 10 micrograms/kg/min) of a dobutamine echocardiographic test (up to 40 micrograms/kg/min) performed 4-5 days after a first acute myocardial infarction, were given a gallopamil intravenous bolus (50 micrograms/kg) 12-24 hours later. Two-dimensional echocardiography was done before and 15 minutes after the bolus. A score index of 1 (normokinesis) to 4 (dyskinesis) and a 16-segment model were used. A segment was considered viable when a resting asynergy (score > or = 2) improvement of > or = 1 grade was seen during low-dose dobutamine. Follow-up echocardiograms were done 3-5 months later. A total of 30 viable segments were found; of these, 10 showed sustained improvement in contractility (group A) during high-dose dobutamine, while 20 exhibited a biphasic response returning to their basal contractile state (group B). After the gallopamil bolus, 9 of 10 group A segments improved their contractility, in comparison with 0 of 20 group B segments (P < .001). Infarct-related vessel significant (> or = 75%) coronary stenosis was present in the tributary vessel of 0 of 10 group A and of 20 of 20 group B segments (P < .001). At follow-up, 9 of 10 group A segments showed a spontaneous contractile improvement; of the 20 group B segments, 8 of 10 that underwent revascularization (7 angioplasty, 3 bypass graft) showed contractile improvement, in comparison with 0 of 10 segments not revascularized (P = .001). We conclude that gallopamil may reverse the contractile dysfunction of postischemic stunned myocardium in patients with acute myocardial infarction, whereas no effects are apparent on ischemic/hibernating myocardium.

Identification of viable myocardium early after acute myocardial infarction under beta-blockade by enoximone echocardiography

The influence of the beta-blocker metoprolol on the capacity either of low-dose dobutamine echocardiography or the recently introduced enoximone echocardiography to detect viable dysfunctioning myocardium after myocardial infarction was investigated. Initial clinical experience would suggest that the phosphodiesterase III inhibitor enoximona could be an alternative pharmacological stimulation, inducing an increase in contractility in the presence or absence of beta-receptor stimulation. Ten patients with a baseline low-dose dobutamine-echocardiographic test (up to 10 micrograms/kg/min) positive for myocardial viability in > or = 1 segment(s), performed 4-5 days after a first acute myocardial infarction treated with rtPA, were randomized after the administration of intravenous metoprolol (15 mg in three 5-mg boluses) either to dobutamine (up to 15 micrograms/kg/min) or to an enoximone intravenous bolus (1 mg/kg over 5 min) under echocardiographic monitoring, in a crossover sequence, with a 24-h interval. The infarct related artery was patent (TIMI grade 2 o 3) in all the patients. Follow-up echocardiograms were performed 5-7 weeks later. Resting asynergy was found in 40 segments; of these, 17 were viable. All the viable segments remained unresponsive during the post-metoprolol dobutamine infusion, while improved their contractility during enoximone echocardiography. Two patients suffering from early post-infarction angina underwent coronary angioplasty successfully. Eight out of ten patients (2 revascularized and 6 not) showed contractile recovery in a total of 14 segments at the follow-up echocardiogram. Sensitivity, specificity and overall accuracy in predicting reversible dysfunction after acute myocardial infarction for enoximone echocardiography were 93, 85, and 88%, respectively. Our results support the value of enoximone echocardiography in the identification of myocardial viability after myocardial infarction, in patients treated with beta-blockers, which interfere heavily with the results of dobutamine echocardiography.

[Early echocardiographic identification of viable myocardium after acute myocardial infarct using inotropic agents: comparison of dobutamine and enoximone]

BACKGROUND

The reversibility of regional dysfunction early after acute myocardial infarction may be obtained with inotropic adrenergic stimulation, in particular during low dose dobutamine infusion, suggesting the presence of viable myocardium. The aim of this study was to determine whether viable myocardium can be identified by two-dimensional echocardiography after an i.v. bolus of enoximone-positive inotropic non-adrenergic drug, phosphodiesterase III inhibitor as well as during dobutamine infusion, in patients with acute myocardial infarction.

METHODS

Twelve male patients, aged 57 +/- 10 years and treated with rtPA (100 mg i.v. in 180 minutes) within the first 6 hours of a first anterior myocardial infarction were studied. All patients underwent a dobutamine infusion (5 and 10 mcg/kg/min, 5 minutes per dose) 4 +/- 1 days after entrance, followed by an enoximone bolus (1 mg/kg over 5 minutes) 1 hour later. Echocardiography was performed before dobutamine and enoximone, during dobutamine, 10 minutes after enoximone and at 6 +/- 2 months follow-up. A Wall Motion Score Index (WMSI) was calculated as recommended by the American Society of Echocardiography. All patients underwent coronarography on days 9-11 post-infarction.

RESULTS

Improvement in regional function of basally asynergic segments occurred in 8 patients during dobutamine infusion, as well as after enoximone i.v. bolus, and in 1 patient only during dobutamine infusion. Both dobutamine and enoximone tests were found to be negative in the other 3 patients. A decrease of WMSI was observed with both dobutamine and enoximone tests (from 1.84 +/- 0.32 to 1.73 +/- 0.31; p = .002 with dobutamine; from 1.84 +/- 0.32 to 1.70 +/- 0.27; p = .0132 with enoximone) with concordant wall motion changes between two tests in 73/84 (87%; K = 0.61) basally asynergic segments. There were no complications occurred during the study. Of 8 patients with positive response for viable myocardium to both tests, 6 had a patent and 2 an occluded infarct-related artery. However, in the latter a collateral circulation toward necrotic area was present. At follow-up improvement in regional function of basally asynergic segments, with a decrease of WMSI (from 1.74 +/- 0.23 to 1.59 +/- 0.24; p < .05), was observed in 4 of 8 patients with viable myocardium detected by either dobutamine or enoximone.

CONCLUSIONS

1) Viable asynergic myocardium may be identified early after acute myocardial infarction by enoximone bolus, as carefully and safely as by dobutamine infusion; 2) transient recovery of post-ischemic myocardial dysfunction may be obtained independently of beta-receptor stimulation.

[The usefulness of the echo-dipyridamole test in the early period after an uncomplicated acute myocardial infarct]

OBJECTIVES

The aim of this study was to examine the ability of Dipyridamole Echocardiography Test (DET)--performed early after an acute myocardial infarction (AMI)--to assess: a) the presence of induced ischemia and its relation with coronary artery stenoses; b) the presence of myocardial viability and the comparison with late wall motion; c) the appearance of cardiac events during hospitalization and in the following period.

METHODS

Ninety-five patients with AMI, subjected to thrombolytic therapy and without complications, underwent a DET on the 4th-5th day. All had a coronary angiography on the 8th-10th day; stenoses were deemed significative when > or = 70%. DET was carried out after drug discontinuance and following standard protocol; parietal kinesis was analyzed according to a 14 segment model. The myocardium was deemed viable when an improvement of a basal dyskinesis was noted; ischemia was considered when a new asynergy appeared or a basal dyskinesis worsened or enlarged; a wall motion score index (WMSI) was calculated. All 95 pts. had a clinical follow-up at 12 +/- 6 months (3-18); 62 pts. had a late echocardiographic examination at 6 +/- 3 months (3-15).

RESULTS

Induced ischemia appeared in 59/95 pts. (62%): in 6/14 pts. (42%) without significative stenoses, in 29/49 pts. (59%) with a single vessel disease, and in 24/32 pts. (75%) with multivessel disease. In identifying multivessel disease, DET sensibility (SE) was 75% and specificity (SP) was 95-97%. In single or no vessel disease WMSI changed from 1.42 to 1.49 (p < 0.0001); in multivessel disease WMSI changed from 1.52 to 1.69 (p < 0.0001). As regards the assessment of diseased vessel(s), DET showed little accuracy when dyskinesis appeared in the basal segments of the inferior and lateral wall or in the mid-apical segments of the anterior and lateral wall; DET properly identified the culprit vessel when dyskinesis appeared in the remaining segments. Myocardial viability was noted in 26% of dyskinetic segments. In single or no vessel disease WMSI changed from 1.41 (basal--> B) to 1.35 (viability phase--> V) and was found 1.31 at the late echocardiography (L): p < 0.0001 between B and V, and between B and L. In multivessel disease WMSI changed from 1.5 (B) to 1.47 (V) and to 1.5 (L): p < 0.05 between B and V, NS between B and L. In comparison with late echocardiography, DET SE was 70%, SP 99%, positive predictive value (PPV) 97%, negative predictive value (NPV) 86%. As regards the prognostic value about cardiac events, DET SE was 80% and NPV was 78%; about only major cardiac events, the respective values are 91% and 97%.

CONCLUSIONS

DET performed early after an AMI allows a better prognostic assessment, as it provides information about: a) the place and the severity of coronary artery stenoses; b) the presence and the extension of induced ischemia and of myocardial viability; c) the risk of subsequent cardiac events.