Adenosine stress protocols for nuclear cardiology imaging.

UNLABELLED: The treadmill test combined with myocardial perfusion imaging (MPI) is a commonly used technique in the assessment of coronary artery disease (CAD). However, there is a group of patients who may not be able to undergo the treadmill test. Pharmacologic stress testing is increasingly utilized for stress perfusion imaging and currently accounts for nearly 40% of all nuclear stress testing [8]. The aim of this study was the introduction of adenosine stress protocols in our nuclear laboratory, and the following, recording and comparing of the frequency and severity of side-effects. METHODS: We performed two kinds of adenosine stress protocols on 186 patients who underwent MPI with radiotracer 99mTc-sestamibi: 1st: 47 patients underwent AdenoSCAN abbreviated protocol IV. adenosin 140microg/kg/min for 3 minutes; 2nd: AdenoEX combined with low level 50W bicycle exercise in 139 patients. We followed and compared side-effects (minor and major events) between AdenoSCAN and AdenoEX protocol, and established an adequate time for imaging of both protocols. RESULTS: Compared with AdenoSCAN, AdenoEX protocol was tolerated by all patients; it reduced all side-effects and improved image quality. Using AdenoEX protocol we found that the heart-to-liver ratio was significantly better, and we established a time of imaging of 15 minutes after stress, compared to the AdenoSCAN time of imaging which was a minimum of 45 minutes after stress. CONCLUSION: This study gives advatages to AdenoEX protocol, because it had fewer side-effects, improved patients' tolerance, improved image quality, and enhanced efficiency and throughput given the opportunity for earlier imaging.

Determination of culprit lesion in patients undergoing elective percutaneous coronary intervention by myocardial perfusion imaging.

UNLABELLED: The aim of this study was to determine and localize culprit lesion by myocardial perfusion imaging (MPI) in cases of angiographically detected coronary narrowing >or= 75% of at least one coronary artery. MATERIAL AND METHODS: One hundred and thirty-two (132) patients with angiographically detected significant coronary narrowing (>or= 75% luminal stenosis of at least one major coronary artery) were studied. All the patients submitted MPI (99m)Tc-MIBI, with pharmacologic dipyridamole stress protocol with concomitant low level bicycle exercise 50W (DipyEX). We measured relative uptake (99m)Tc-MIBI for each myocardial segment using short-axis myocardial tomogram study. A 5-point scoring system was used to assess the difference between uptake degree in stress and rest studies for the same segments, and we created two indices: Sum reversibility score (SRS), Index of sum reversibility score (ISRS). RESULTS: A total of 396 vascular territories (2244 segments) were analyzed before elective percutaneous coronary intervention (ePCI). Overall sensitivity, specificity and accuracy using SRS were 90.2%, 87.5%, and 89.4%, with a positive predictive value of 94.1%. Overall sensitivity, specificity, and accuracy using ISRS were 94.4%, 90.6%, 93.2% and the positive predictive value was 95.7%. CONCLUSION: DipyEX MPI with the two indices created, SRS and ISRS, significantly improves sensitivity, specificity and accuracy in the determination and localization of culprit lesions in patients undergoing elective PCI.

Diagnostic value of biohumoral markers of necrosis and inflammation in patients with right ventricular myocardial infarction.

INTRODUCTION/AIM: Patients with right ventricular myocardial infarction (RVMI) and patients with left ventricular myocardial infarction (LVMI) of the anterior wall with ST-elevation (STEMI), due to the profundity and volume of the necrosis, tend to have a more severe and more complicated clinical outcome as well as a higher mortality level compared to patients with myocardial infarction of inferoposterior localization in the left ventricle (IPILK), without the right ventricle being overtaken. C-Reactive protein (CRP) is a sensitive and reliable indicator of acute inflammation and is in good correlation with creatin kinasis (CK) or the enzymes which indicate necrosis markers in acute myocardial infarction (AIM). Because of this, a common biohumoral answer is of greater importance and more reliable both diagnostically and prognostically; it signifies a more severe and more complicated clinical outcome, especially on the rupture of the myocardium. The main goal of this study was to compare the maximum values of enzymes and CRP in patients with RVMI and LVMI who had first STEMI and who were in the acute phase treated with percutaneous transluminal coronary angioplasty (PTCA). METHODS: During a six-year period (2000-05), in the Clinic for Urgent Internal Medicine at the Military Medical Academy, a total of 74 patients included in a prospective study were divided into two groups. The first group consisted of patients with RMI 19 (25.67%), and the second group of patients with LMI 55 (74.33%). The patients in both groups received a percutaneous coronary intervention (PCI), if they had been admitted in the first 4 hrs from the beginning of the chest pain, and if there were no contraindications. All the others received thrombolitic therapy, and a "rescue" PCI if needed, in the next 24-48 hours. The risk factors, clinical outcome, necrosis and inflammation biomarkers (enzymes and CRP), coronary status, restenosis of stent, and intra-hospital mortality rate in the first month, as well as a long term prognosis over a period of one year, were analysed. RESULTS: The average age of the patients in the group with RVMI 19 (7 m + 12 f) was 66.1 +/- 11y, and in the group with LVMI 55 (45 m + 10 f) 59.6 +/-13y, with a statistical trend which indicated that the patients with RVMI were older (66.1 +/- 11y vs. 59.6 +/- 13y, p < 0.061) and that women dominated (63.1% vs. 18.8%, p < 0.001). No statistical differences were found between the two groups of patients concerning the length and the appearance of the chest pain before admission to the hospital and the beginning of the PCI treatment, as well as risk factors such as smoking, cholesterol or diabetes. Of the total of 74 patients with the first STEMI as a primary manifestation of a coronary disease, we performed a primary PCI on 58 (78.37%), and a "rescue" PCI on 16 (21.63%) after the thrombolitic therapy during the 24-48h after admission. We had no cases of death either during the primary or the delayed PCI, or in the next 24h following the intervention. During the hospital phase of treatment, in the group with RMI the causes of death were the rupture of the free wall of the right ventricle (1), acute pancreatitis (1), ARDS and hypostatic pneumonia (1), cerebrovascular insult (1). During the following year, one more patient died due to reinfarction of the anterior localization. In the group with LMI, during the hospital phase of treatment 5 (9.09%) patients died: reinfarction (2), rupture of the left ventricle (1), respiratory insufficiency and severe hypostatic pneumonia (1), cerebrovascular insult (1). During the following year, 4 more patients died, sudden death (2), ischemic dilatative cardiomyopathy (2). The total mortality rate over a one-year period of observation in the group with LMI was 9 (16.3%), and in the group with RMI 5 (26.3%). Radionuclide ventriculography (RNV) was performed in the acute phase of myocardial infarction from 7-14 days after PCI and after 6 months in both groups as an independent indicator of the ejection fraction (EF) of both ventricles. The given results show that a statistically proven significant difference exists in the recovery of the right ventricle in acute phase RMI (49.1 +/- 7.9 vs. 35.4 +/- 10, p< 0.001), as well as after 6 months (49.2 +/- 9.7 vs. 38.3 +/- 11.2, p < 0.010) in patients with RMI. CONCLUSION: Primary PCI should be done whenever it is possible with all patients who have a great volume and depth of necrosis, especially if that is the first manifestation of a coronary disease and the first acute STEMI, as were all of our patients in both groups. Our results show that older patients with RMI, and dominantly women, have a more severe and more complicated clinical outcome in the acute phase of RMI compared to patients with LMI of the anterior wall. In the longer prognosis of this case, they have a quicker and a more complete recovery of the right ventricle due to which they have a better immediate and long term prognosis, but demand careful overseeing and energetic treatment in the acute phase of the myocardial infarction, especially considering that their treatment is often specific compared to patients with an infarction of the left ventricle.

[Stress-rest myocardial tomoscintigraphy with 99mTc-tetrofosmin in the diagnosis of ischemic disease]. / Stress-rest tomoscintigrafija miokarda 99mTc-tetrofosminom u dijagnostici ishemijske bolesti.

The aim of this study was to evaluate the accuracy of 1-day stress-rest technetium-99m tetrofosmin myocardial tomography in the identification of patients with coronary artery disease (CAD), and in the detection of the individual occluded coronary vessels. A total of 42 patients with suspected CAD were studied. Significant coronary narrowing (> or = 50% luminal stenosis) was detected by angiography in 22 patients. All patients received two i.v. injections of 99mTc tetrofosmin, one at peak exercises (370 MBq) and the other (740 MBq) at rest 3 h after exercise (images 15-30 min after injections for both studies). At visual analysis, all patients with CAD (> or = 50% luminal stenosis) (n-22) had an abnormal 99mTc tetrofosmin tomogram. Nine out of 20 patients without significant coronary narrowing (but with tortuosis, atheromathosis, with microvascular diseases) showed abnormal findings. Overall sensitivity, specificity and diagnostic accuracy in the identification of CAD was 100%, 55%, and 79%, respectively. Sensitivity, specificity and diagnostic accuracy in the identification of individuals with occluded coronary vessels were 100%, 76% and 85%, respectively. The results of this study demonstrate that 1-day exercise-rest 99mTc tetrofosmin single-photon emission tomographic imaging (SPET) is a suitable and accurate technique to identify patients with CAD and for detection of individual occluded coronary vessels.

[Clinical study of administration of abciximab--a monoclonal antibody to platelet glycoprotein IIb/IIIa in percutaneous intracoronary interventions]. / Klinicka studija o primeni monoklonskog antitela protiv IIb/IIIa glikoproteina trombocita--abciksimaba kod bolesnika sa perkutanom intrakoronarnom intervencijom.

During the last 10 years a new group of drugs was developed--platelet glycoprotein IIb/IIIa blockers that is nowadays largely and efficiently used as for the prevention of percutaneous coronary intervention complications as well as in the treatment of acute coronary syndromes. In the period February-June 2000--19 patients (18 males, 1 female, of average age 53.3 years) were administered Abciximab in the bolus dose of 10 mg immediately before the intervention and afterwards 10 mg by 12-hour infusion. All patients received aspirin and ticlopidine hydrochloride if the stent was introduced and heparin by the standard protocol. Elective intervention was done in 17 patients (non-Q infarction in 3 patients, unstable angina pectoris in 5 patients, postinfarction angina pectoris in 2 patients, acute myocardial infarction at least 1 month before the intervention in 6 patients and 1 patient with myocardiopathy) and in 2 patients the intervention was performed during the myocardial infarction. In 15 patients (79%) intracoronary stent was introduced and in 5 patients (21%) the intervention was performed on 2 arteries. Maximal immediate effect of the dilatation was achieved in 18 patients (94.7%). In the first 60 days of the follow-up 1 patient (5%) died of some other disease, and in no patients symptomatic myocardial ischemia was found. No adverse effects were observed.

[Myocardial reinfarction]. / Reinfarkt miokarda.

A total number of 1924 patients were treated for acute myocardial infarction (AMI) at the Clinic for Urgent Medicine at the Military Medical Academy during the period of seven years (1991-1997). These myocardial infarctions were at different locations, the mean age of patients was 63.7 +/- 6.2, in male patients 1192 (61.9%) and 732 (38.1%) in female ones. Out of that number of patients, 406 (21.1%) had recurrent myocard infarction (RMI), 254 (62.6%) males and 152 (37.4%) females, of average age 64.8 +/- 8.3 years. Statistically, no significant differences were observed in those two groups of patients, concerning their age, location of myocardial infarction and administration of fibrinolytic therapy. There were, however, significant differences concerning the complications, primarily cardiac insufficiency, malignant arrhythmias, AV block II0 and III0, applications of temporary or permanent pacemaker and finally mortality. During intrahospital phase of treatment, in the first few months, obtained results revealed that the patients suffering from RMI had multiple and serious complications and that cardiac insufficiency was the main cause of high mortality rate in those patients.

[Combined myocardial infarct of the left and right ventricle]. / Kombinovani infarkt miokarda leve i desne komore.

Combined myocardial infarction of left and right ventricle (CMILRV) of inferoposterior localization represents simultaneous acute necrosis of both myocardial ventricles and belongs, due to associated and frequent complications, to more severe damages of the myocardium with high mortality. Our group consisted of 100 patients of both sexes, mean age of 67.4 years, of which 50 were with inferoposterior left ventricular infarction and 50 with CMILRV of the same localization. The diagnosis was confirmed clinically, by ECG, by the analysis of enzymes, echocardiographically and scintigraphically using radionuclide ventriculography with 99Tcm PyP. Selective coronarography was performed in all the survived patients, and autopsy of the dead. On the basis of clinical presentation of some forms of dynamic weakness of the heart, in acute stage of CMIRLV, we have established that there are 4 categories of these patients, so that each of these groups represents also a special clinical form, which are: 1. CMIRLV without signs of heart failure, established in 20 (40%) cases, which clinically and prognostically do not differ from inferoposterior left ventricular infarction. 2. CMIRLV with predominant failure of the right ventricle was found in 17 (34%) of the patients with a specific clinical feature and the way of treatment. 3. CMIRLV with marked failure of the left ventricle, found in 8 (16%) of the patients, which required combined treatment measures. 4. CMIRLV with general heart failure, established in 5 (10%) cases, is characterized by cardiogenic shock and falls into the most severe forms of this kind of myocardial infarction. Total mortality in the patients with CMILRV was 10% (5.50), that is 40% (2.5) in both the second and the fourth subgroup, 20% (1/5) in the third group, while in the first one as well as in the control group with inferoposterior infarction there was no mortality. Good knowledge of the above mentioned clinical forms of CMILRV are necessary prerequisite for application of specific and corresponding therapeutic measures and the best prevention of associated complications and high mortality of such patients.

[Use of 99mTc-pyrophosphate and coronarography in the diagnosis of simultaneous myocardial infarct of the right and left cardiac ventricles]. / Primena 99mTc-pirofosfata i koronarografije kod dijagnostikovanja istovremenog infarkta desne i leve komore srca.

Myocardial scintigraphy was performed using 99m-Tc-pyrophosphate in 50 patients with suspected coexisting right ventricular and left inferior ventricular heart infarction and in 50 patients with left inferior ventricular infraction only. In all survived patients additional selective coronarography was performed and in all died patients autopsy was performed. The aim of the study was to evaluate reliability of myocardial scintigraphy using 99m-Tc-pyrophosphate in the diagnosis of coexisting infarction of both heart ventricles. In a group of patients with coexisting right and left ventricular infarction (45 proved by coronarography, and 5 by autopsy), scintigraphic finding was confirmed in 46 (93%) patients. In all 50 patients with left inferior ventricular infarction, scintigraphic finding was confirmed in 48 of them by coronarography and in 2 by autopsy (100%). Of 4 patients with false negative scintigraphic finding 2 were treated with fibrinolytic therapy immediately after admission and in 2 diffuse occlusive changes were found on all three blood vessels by coronarography. It has been concluded that myocardial scintigraphy using 99m-Tc-pyrophosphate is a very sensitive (92%), specific (100%), exact (96%), simple and safe diagnostical method in detecting coexisting acute infarction of both heart ventricles.

[Value of the stress test in the evaluation of the severity of ischemic heart disease]. / Vrednost testa opterecenja u proceni tezine ishemijske bolesti srca.

Loading test was used in 156 patients with ischemic heart disease and the results of their selection are presented. In all patients occlusive coronary disease was detected by selective coronarography. They were divided in three groups. Two groups of patients had a high risk ischemic heart disease requiring surgical revascularization of the myocardium and selective coronarography. The first of these two groups comprised 48 patients with significant stenosis of the main tree of the coronary artery and the second comprised 35 patients with equivalent stenosis of this artery. The third group comprised 73 patients with ischemic heart disease of small risk in whom occlusive changes of the coronary arteries were of distal localization. The statistically significant difference was found between the two groups of patients with high risk and the third group with small risk according to early development of ST depression in the first minutes of loading, its degree, number of leads with ST depression, form and its maintenance after cessation of loading. The difference was also significant regarding the submaximal pulse rate and systolic blood pressure during loading test. It has been concluded that by using loading test as a functional diagnostic method patients with a high risk ischemic heart disease can be selected stressing the advantage of physiology over morphology.