Cardiac and pulmonary calcification in a hemodialysis patient: partial regression 4 years after parathyroidectomy.

AIMS: The reversibility of extraskeletal calcifications in dialysis patients is an important and unresolved issue. Although periarticular calcifications have been shown to be reversible, little data are available on vascular or parenchymal calcifications. CASE HISTORY: A patient on maintenance hemodialysis with severe hyperparathyroidism, hypercalcemia and hyperphosphatemia was admitted to undergo parathyroidectomy. A preoperative total body bone scintigraphy was performed to better evaluate a lytic lesion in the pelvis, the histology of which proved to be a "brown tumor". The scan showed the typical findings of renal osteodystrophy, but also a diffuse extra-skeletal uptake of bone tracer in the lungs, kidneys, femoral arteries and myocardium. After surgery, good control of serum calcium, phosphate (Ca x P product < 50 mg2/dl2) and PTH levels was maintained during 4 years of follow-up. Bone scans were repeated after 2 and 4 years, showing marked improvement of periarticular uptake at the ends of long bones. Extraosseous calcium deposition was still markedly evident, but progressively decreased (at 4 years: heart -36%, lungs -18%). CONCLUSION: In this dialysis patient, extraskeletal calcification of visceral organs (particularly in the heart and the lungs) due to prolonged hypercalcemia and hyperphosphatemia was partially reversible by parathyroidectomy followed by good long-term control of serum phosphate and calcium.

Peripheral quantitative Computed Tomography (PQCT) in the evaluation of bone geometry, biomechanics and mineral density in postmenopausal women.

AIM: Non-invasive assessment of bone geometry, biomechanics, and mineral content in postmenopausal women by peripheral quantitative Computed Tomography (pQCT). MATERIAL AND METHODS: Total, trabecular and cortical mineral density (totBMD, cortBMD, trabBMD), and the geometrical (total area, trabecular area, cortical area) and biomechanical properties of bone (strength-strain index, cortical thickness) were assessed in 93 consecutive post-menopausal women (mean age: 63+/-7 yrs; age at menopause: 49+/-6 yrs; years since menopause: 14+/-9 yrs) by pQCT at the ultradistal radius of non-dominant forearm. RESULTS: Compared with 50 healthy women at peak of bone mass, volumetric total, trabecular and cortical bone densities were significantly reduced in postmenopausal subjects (TotBMD: 318+/-106 mg/cm3 vs ctr 442+/-100, -28%, p<0.001; TrabBMD: 117+/-59 mg/cm3 vs ctr: 203+/-47, -42%, p<0.001; CorBMD: 764+/-159 mg/cm3 vs 921+/-111, -17%, p<0.001). The bone loss was greater in trabecular bone. Cortical area (0.7+/-0,1 cm2 vs ctr: 0.8+/-0.1, -12.5%, p<0.001), cortical thickness (0.151+/-0.02 cm vs ctr: 0.169+/-0.03, -11%, p<0.001), and strength-strain index (686+/-207 mm3 vs ctr: 883+/-165, -22%, p<0.001) were significantly lower in post-menopausal women in comparison with the controls. Years since menopause and age showed a significant negative correlation with bone mineral densities and biomechanical parameters. CONCLUSIONS: In post-menopausal women pQCT showed: 1) osteopoenia in all bone compartments, greater at the trabecular level, related to age and years since menopause; 2) reduced cortical density and cortical thickness, consistent with a reduced ability of bone to absorb loading forces; 3) reduced strength-strain index, indicative of inability to adapt to mechanical use and augmented risk for fracture. We conclude that pQCT is a valuable tool for measuring the true volumetric mineral density and the geometrical and biomechanical indexes of bone, which could be proposed in current clinical practice for the assessment of osteoporosis.

The good and evil of HAART in HIV-related progressive multifocal leukoencephalopathy.

The use of highly active anti-retroviral therapy in patients with HIV-related progressive multifocal leukoencephalopathy is associated with increased survival and disease stabilization. However, approximately half of the patients receive no benefit from these treatments. In a group of HIV-infected patients with histologically or virologically confirmed PML, we recognized two distinct patterns of response, i.e., long survivors versus nonresponders, but could not identify any factors at baseline predictive of PML outcome. In addition, the use of cidofovir did not substantially affect survival. However, the survival rate was higher during the first years of HAART, i.e., 1996-1997, with better outcomes observed in patients receiving a protease inhibitor-containing regimen either irregularly or after a switch from a 2-nucleoside reverse transcriptase inhibitor combination. In contrast, PML outcome was frequently poor in both HAART-naive and -experienced patients who responded promptly to anti-HIV therapy in terms of CD4 increase and viral load decrease. In addition, in a number of patients, PML onset was temporally associated with immune reconstitution. It may be that, in some patients, rapid immune reconstitution due to HAART paradoxically worsens the course of PML. Gradual reversal of immune deficiency might be associated with better outcome.

Post-stress end-systolic left ventricular dilation: a marker of endocardial post-ischemic stunning.

Several studies have shown the accuracy of gated single photon emission computed tomography (SPECT) using thallium-201 and technetium tracers in the assessment of myocardial perfusion and function. Gated SPECT has been successfully utilized to detect post-stress left ventricular ejection fraction (LVEF) reduction resulting from post-ischemic stunning in patients with coronary obstruction. The aim of this study was to evaluate whether the post-stress LVEF impairment could be related to the post-stress end-systolic ventricular dilation resulting from post-ischemic endocardial stunning. Two hundred and eighty-two consecutive patients were studied by conventional diagnostic 2 day stress/rest gated SPECT following injection of 925 MBq of 99mTc-tetrofosmin using a dual-headed SPECT camera. One hundred and forty-seven of these patients (52%) showed reversible perfusion defects, 69 (24%) permanent defects and the remaining 66 (24%) had normal perfusion. One hundred and thirty-eight of these patients had a history of myocardial infarction (MI) and 19% underwent coronary angiography without an intervening cardiac event. Perfusion was analysed on ungated images using 20 segments scored on a five-point scale (0, normal; 4, no uptake), while wall thickening (WT) was assessed visually on stress/rest end-systolic images using a four-point score (0, normal; 3, absence of WT). LVEF and volumes were calculated using an automatic algorithm. The post-stress and rest ratios were determined for both end-diastolic (EDV) and end-systolic (ESV) volume. Normal values for all these parameters were obtained using data from 149 patients with a low likelihood (<5%) of coronary artery disease (CAD). In 50 of the 147 (34%) of patients with reversible perfusion defects, post-stress LVEF was >5% lower than rest values (stunned group), while the remaining 97 patients did not show a significant LVEF change (group 2A). The percentage of patients who developed exercise-induced angina, the percentage of patients who underwent coronary angiography and the segmental summed perfusion and WT scores were significantly higher in the stunned group compared with group 2A. Only ESV increased significantly post-stress, and this increase occurred only in stunned patients. Both EDV and ESV ratios were significantly higher in the stunned group compared with normal controls (P=0.008 and P<0.000001, respectively) and with the subgroup 2A (P=0.011 and P<10(-12), respectively). The ESV stress/rest ratio correlated significantly with the summed WT difference score by univariate analysis in stunned patients. It can be concluded that the post-stress ESV dilation, obtained by stress/rest gated SPECT, seems to be due to endocardial post-ischemic stunning. The stunned patients showed more severe clinical, angiographic, perfusion and function parameters.

Effect of genotypic resistance on the virological response to highly active antiretroviral therapy in cerebrospinal fluid.

Paired plasma and cerebrospinal fluid (CSF) specimens drawn from 15 HIV-infected patients with neurological disease before and after a median 6-week duration of highly active antiretroviral therapy (HAART) were studied to assess the short-term virological response of CSF and whether this can be predicted on the basis of baseline resistance mutations. After treatment, the median plasma and CSF viral load (VL) decreased by, respectively, 2.08 log10 (p = 0.0001) and 0.91 log10 copies/ml (p = 0.007) in comparison with baseline. A plasma virological response was observed in all but one patient, whereas the posttreatment CSF VL increased, remained unchanged, or decreased at a substantial lower rate than in plasma of six "CSF non/slow responders" (40%). Direct sequencing of baseline specimens showed that none of these patients had reverse transcriptase (RT) or primary protease resistance mutations in the CSF alone, but two had RT mutations conferring high-level resistance to drugs included in the HAART regimen in both CSF and plasma. The other four patients had no RT or primary protease resistance mutations. There was no significant difference in the nucleotide diversity of the CSF and plasma RT sequences, baseline plasma or CSF VL, the CSF-to-plasma VL ratio, the number of CSF cells, the CD4+ cell counts, or the history of antiretroviral treatment between the CSF non-slow responders and the other patients. During this short-term follow-up and despite a plasma response, a significant proportion of HAART-treated patients with neurological symptoms showed a slow or absent CSF response. Most of these cases were not associated with the presence of resistant HIV strains in the CSF.

Comparison of three nucleic acid amplification assays of cerebrospinal fluid for diagnosis of cytomegalovirus encephalitis.

The diagnostic reliabilities of three cytomegalovirus (CMV) nucleic acid amplification assays of cerebrospinal fluid (CSF) were compared by using CSF samples from human immunodeficiency virus-infected patients with a postmortem histopathological diagnosis of CMV encephalitis (n = 15) or other central nervous system conditions (n = 16). By using a nested PCR assay, the quantitative COBAS AMPLICOR CMV MONITOR PCR, and the NucliSens CMV pp67 nucleic acid sequence-based amplification assay, sensitivities were 93.3, 86.6, and 93.3%, respectively, and specificities were 93.7, 93.7, and 87.5%, respectively. The COBAS AMPLICOR assay revealed significantly higher CMV DNA levels in patients with diffuse ventriculoencephalitis than in patients with focal periventricular lesions.

Radio-guided video-assisted parathyroidectomy: a preliminary report.

BACKGROUND: The surgical management of primary hyperparathyroidism is changing both in terms of the extent of cervical exploration and in technique. There are many new mini-invasive procedures for neck surgery. We describe our preliminary experience with a technique that combines two mini-invasive procedures--radio-guided and video-assisted parathyroidectomy. METHODS: Six consecutive patients with no recurrent or persistent primary hyperparathyroidism, no previous cervical operations, and no thyroid pathologies were selected to undergo radio-guided video-assisted parathyroidectomy. RESULTS: One case was converted. There was no morbidity or mortality in the postoperative period. Six parathyroids were removed; the histological diagnosis was adenoma in all cases. All patients were discharged on the 1st postoperative day. Calcium serum levels normalized in all cases, with only one case of transient postoperative hypocalcemia. All patients were normocalcemic after 6 months. CONCLUSION: Radio-guided video-assisted parathyroidectomy is feasible in selected patients. However, longer follow-up and more cases are necessary before this procedure can be applied routinely.

Homocysteine concentration in primary and systemic sclerosis associated Raynaud's phenomenon.

OBJECTIVE: To investigate whether patients with systemic sclerosis (SSc) have raised homocysteine (Hcy) plasma levels, thought to be an independent risk factor for vascular disease, and to study the relationship between Hcy and endothelial damage, and between Hcy and methylene-tetrahydrofolate reductase (MTHFR) genotypes, and patients' vitamin nutritional status, which are among the more frequent causes of hyperhomocysteinemia. METHODS: We measured Hcy, von Willebrand factor (vWF), folic acid, and vitamin B12 plasma levels and analyzed the frequencies of MTHFR mutations in 30 patients with SSc and 12 patients with primary Raynaud's phenomenon (RP); 29 healthy subjects served as controls. RESULTS: Patients with SSc had higher Hcy and vWF concentrations than those with RP (p < 0.01 and p < 0.02, respectively) or controls (p < 0.02 and p < 0.0001, respectively). Folic acid and vitamin B12 were lower in SSc than in RP (p < 0.01 and p < 0.02, respectively) or controls (p < 0.05). MTHFR genotype did not influence Hcy, folate, or vitamin B12 concentrations, but patients homozygous for the mutant gene had higher vWF levels. CONCLUSION: Patients with SSc, but not those with RP, had significantly higher Hcy and vWF plasma levels. Nutritional rather than inherited factors seem to have a pathogenic role in SSc hyperhomocysteinemia.

99mTc-sulfur colloid gastroesophageal scintigraphy with late lung imaging to evaluate patients with posterior laryngitis.

UNLABELLED: The aim of this study was to use gastroesophageal and pulmonary scintigraphy to evaluate the prevalence of gastroesophageal reflux and airway involvement among patients with posterior laryngitis. METHODS: The study included a total of 201 patients (131 females, 70 males; age range, 15-77 y; mean age +/- SD, 49 +/- 16 y). All patients had posterior laryngitis documented by laryngoscopy and symptoms such as a dry cough, painful swallowing, and hoarseness. A control population of 20 healthy volunteers (13 females, 7 males; age range, 19-74 y; mean age, 53 +/- 13 y) was also evaluated. After a 12-h fast, all subjects underwent gastroesophageal scintigraphy through administration of 300 mL orange juice labeled with 185 MBq 99mTc-sulfur colloid. After 18 h, planar anteroposterior thoracic images were acquired with the subjects supine. RESULTS: Sixty-seven percent of patients (134/201) had scans positive for gastroesophageal reflux; of these, 30 (22%) had distal reflux and 104 (78%) had proximal reflux. In addition, the scans of 31 patients were positive for proximal reflux-associated pulmonary uptake. The frequency, duration, and degree of reflux episodes were significantly greater in patients with proximal reflux than in patients with distal reflux (P < 0.001). The 67 patients in whom reflux was not detected had diseases or reflux-associated cofactors that could account for laryngeal symptoms. No statistically significant difference in symptoms or esophageal motility parameters could be identified among the patient groups, but patients with proximal reflux had significantly prolonged gastric emptying times compared with healthy volunteers. CONCLUSION: Most patients with posterior laryngitis had detectable proximal gastroesophageal reflux. Exposure of the proximal part of the esophagus to acid, by setting the stage for microaspiration of gastric material into the larynx, remains a major cause of damage to the laryngeal mucosa. Slowed gastric emptying may be a predisposing factor. Moreover, symptoms such as a dry cough, painful swallowing, or hoarseness may not be reliable predictors of the presence of gastroesophageal reflux or of associated airway involvement.

[Osteoporosis and phytoestrogens: an assessment of bone mineral density via quantitative peripheral computed tomography in milk-egg-vegetarian women in the premenopause]. / Osteoporosi e fitoestrogeni: valutazione della densità minerale ossea mediante Tomografia Computerizzata quantitativa periferica nelle donne lattoovovegetariane nella premenopausa.

PURPOSE: Noninvasive assessment of bone mineral density, geometrical and biomechanical properties in premenopausal women with dietary intake of phytoestrogens and comparison of these parameters with those of age-matched female subjects with "Mediterranean" dietary intake lacking in these substances. MATERIAL AND METHODS: Volumetric cortical, trabecular and total mineral density and bone geometrical properties were evaluated in 15 female subjects with phytoestrogens dietary intake. Peripheral quantitative Computed Tomography (pQCT) was used to make measurements at the distal radius of the nondominant forearm. Fifteen age-matched subjects with "Mediterranean" dietary intake were chosen as a control group. Cross-sectional area (Total A), trabecular area (TA), cortical area (CA), cortical thickness (CThk) and strength strain index (SSI) were assessed as biomechanical parameters. RESULTS: Daily consumption of phytoestrogens was significatively different in the two groups (phy: 17.45 mg/die vs ctr: 0.35; p < 0.0005), while calcium intake was similar (phy: 652 mg/die vs ctr: 650). Total (0.460 g/cm3 vs ctr: 0.433) and trabecular (phy: 0.209 g/cm3 vs ctr: 0.189) bone mineral densities, such as SSI (phy: 925 mm3 vs ctr: 894) values, were higher in women with dietary intake of phytoestrogens, in comparison with the relative controls, but not significantly (p = ns). Among geometrical parameters, total area and cortical area were tendential in women with a vegetarian diet while cortical thickness was the same in both groups. CONCLUSIONS: pQCT showed higher bone mineral density (total and trabecular) and SSI values in premenopausal women with dietary intake of phytoestrogens. Despite the lack of statistical significance, these preliminary results, should further support the few literature findings about the potential role of phytoestrogens consumption in preventing trabecular bone loss. However, further studies are warranted to evaluate definitively the efficacy of phytoestrogens in preventing postmenopausal osteoporosis.

Molecular analysis of cerebrospinal fluid: potential for the study of HIV-1 infection of the central nervous system.

The molecular analysis of cerebrospinal fluid (CSF) provides an inestimable tool for the study of HIV infection of the central nervous system (CNS). Current nucleic acid amplification techniques enable the measurement of CSF HIV-1 RNA levels which can be predictive of HIV-associated neurological damage. CSF HIV-1 RNA levels do not necessarily correlate with the corresponding plasma levels, thus supporting the possibility of an intrathecal virus production, i.e., from brain macrophages. However, in early stages of HIV infection, as well as during some opportunistic CNS diseases, CNS or CSF infiltrating lymphocytes might be the main source of CSF virus. A drastic decrease in CSF viral load is usually observed along with a decrease in plasma levels in patients receiving highly active antiretroviral therapy (HAART), with durable suppression of CSF viral load over months. However, during the first weeks of therapy, the dynamics of response may differ in the CSF as compared to plasma, again suggesting that virus replication may be compartmentalised in the CSF. A number of mechanisms are likely to be involved in the response to therapy in CSF, including among the others the trafficking of cell populations supporting viral replication between blood, CNS and CSF, and the role of the anatomical brain barriers in limiting the access of antiretroviral drugs into the CSF. A potential risk associated with compartmentalisation of HIV infection is of an incomplete suppression of virus replication in the CSF, thus creating the ground for local development of anti-HIV drug resistance. In order to assess this occurrence, long-term studies of viral load and genotypic analyses on paired CSF and plasma will be necessary and these will also help elucidate the complex interrelationship between viral replication in these compartments.

Effects of infusion of glucose-insulin-potassium on myocardial function after a recent myocardial infarction.

UNLABELLED: We studied the effects of glucose, insulin, and KCl infusion (GIK), on regional myocardial perfusion and function by 99m-Tc-tetrofosmin-gated SPECT. METHODS: We studied 21 male patients with their first uncomplicated acute myocardial infarction (AMI). All patients underwent a rest and submaximal stress before and after 24-hour infusion of GIK-solution (group A) or saline solution (group B). RESULTS: Group A showed better stress tolerance and ischaemic threshold improvement after GIK infusion whilst no statistical differences were found between basal and post-infusion test in group B. At first the stress test in group A, of the 192 segments analysed, 52 (27%) showed reversible perfusion defect. In group B, of 144 segments analysed, 31 (21%) showed reversible perfusion defect. A post-infusion analysis in group A showed a post-GIK end-diastolic significant count improvement in 21 segments, and a post-GIK end-systolic count improvement in 22 segments. In group B, perfusion increase was observed only in 4 segments, whilst systolic thickening increase was observed only in 1 segment. CONCLUSION: These data demonstrate the efficacy of GIK infusion to improve regional myocardial perfusion and function mainly in segments adjacent to the recently infarcted area.

[Detection and assessment of myocardial stunning with perfusion tomographic scintigraphy using gated SPECT]. / Rivelazione e valutazione di stordimento miocardico mediante tomoscintigrafia di perfusione con metodica gated-SPECT.

BACKGROUND: Gated-SPECT using 99mTc-labeled flow tracers provides the simultaneous assessment of global and regional myocardial perfusion and function. The aim of this study was to identify patients with stress-induced postischemic stunning, among those with reversible stress perfusion defects, and patients with artifactual defects among those with fixed defects, in order to assess the value of the functional data provided by gated acquisition of perfusion imaging in the characterization of ischemia. METHODS: We studied 221 consecutive patients who underwent conventional diagnostic dual day stress/rest gated-SPECT following injection of 925 MBq of 99mTc-tetrofosmin using a dual head SPECT camera, 115 of whom (52%) showed reversible perfusion defects, and 66 (30%) fixed defects. Perfusion was analyzed on ungated images using 20 segments scored on a 5-point scale (0 = normal, 4 = no uptake), while wall thickening was assessed visually on stress/rest end-systolic images using a 4-point score (0 = normal, 3 = absence of wall thickening). Left ventricular ejection fraction and volumes were calculated using an automatic algorithm (quantitative gated-SPECT). Fifty-two out of 221 (23.5%) patients underwent coronary angiography. RESULTS: In 40/115 (35%) patients with reversible perfusion defects, post-stress left ventricular ejection fraction was > 5% lower than that at rest (Group A: stunned), whereas in the remaining 75 patients, post-stress left ventricular ejection fraction was either +/- 5% or greater than that at rest (Group B: non-stunned). Peak exercise angina and ischemic electrocardiographic response to exercise were present in 79 and 58% respectively of Group A patients and in 33 and 39% of Group B patients. The number of patients with multivessel disease was significantly higher in Group A compared to Group B (58 vs 41%, p < 0.05). The total stress and rest perfusion scores were significantly higher in Group A than in Group B (p < 0.01); even the total stress wall thickening score was significantly higher in Group A (p < 0.001). As for global parameters, post-stress end-systolic volume was significantly higher in the stunned group (p < 0.05). In 40 out of 66 (60.5%) patients without reversible ischemia fixed defects were judged to be ischemic (Group C), while in 26/66 (39.5%) they were attributed to attenuation artifacts (Group D). Eighty percent of Group C patients had a previous myocardial infarction against none of Group D. Stress/rest perfusion and wall thickening scores were significantly higher in Group C than in Group D. CONCLUSIONS: Gated-SPECT myocardial perfusion evaluation allowed us to identify a subgroup of post-stress stunned coronary artery diseased patients. The post-stress left ventricular ejection fraction reduction in this population seems to be due to the increase in end-systolic volume. The stunned patients showed more severe perfusion defects and wall thickening abnormalities.

Labelled leukocytes for diagnosis of infectious diseases. Our experience in labelling and clinical usefulness.

BACKGROUND: To review our experience in infectious diseases diagnosis, using a simple labelling technique. METHODS: We made 101 scans in 91 patients with suspected infectious diseases confirmed by clinical, histologic or cultural specimens; a clinical or instrumental follow-up was available for every patient. Patients were divided into four subgroups: A: Inflammatory Bowel Diseases; B: Septic Syndromes; C: Bone diseases; D: Others. We used 99mTc-HMPAO in 80 scans and 111In in 21. In 20/80 frozen and stored HMPAO was used. RESULTS: 99mTc-HMPAO frozen and stored labelling yield was: 60%(SD15%), 99mTcHMPAO: 62(12)(p n.s.), 111In 75%(10%), (p < 0.05). Frozen-stored HMPAO was sterile and apyrogen. 27 had positive scan without leukocytosis or neutrophilia. No correlation between leukocytosis or neutrophilia and yield was observed. Transit lung times ranged between 14-16 min without differences among three radiopharmaceuticals. In each Group and in the sample as a whole True Positive, False Positive, True Negative, False Negative, Sensitivity, Specificity and Accuracy, were calculated. In Group B and in the sample as a whole Predictive Positive Value and Negative Predictive Value were also evaluated. CONCLUSIONS: Labelling yields and "viability" were good using the three radiopharmaceuticals; labelling procedure was simple and safe. Accuracy PPV, NPV, cost-effectiveness were good; 111In is the choice for diagnosis of bone and joint infections. Frozen-stored HMPAO should be introduced as a cost-saving labelling procedure in practice.

Myocardial viability assessment after acute myocardial infarction: low-dose dobutamine echocardiography versus rest-redistribution thallium-201 SPECT.

BACKGROUND: The presence of tissue viability is of great importance in the prognostic work-up of patients recovering from acute myocardial infarction. However, uncertainty still exists concerning the optimal tool for its assessment. The present study was undertaken in order to compare low-dose dobutamine echocardiography and rest-redistribution thallium SPECT for predicting late improvement of regional left ventricular function after acute myocardial infarction. METHODS: Fifteen patients undergoing coronary angiography, low-dose dobutamine echocardiography and rest-redistribution thallium SPECT after thrombolyzed anterior acute myocardial infarction were studied. A 3 month follow-up echocardiogram was performed in all patients and 9 underwent coronary revascularization. RESULTS: A significant (> or = 70%) residual stenosis of the infarct-related artery was present in 14 patients, whilst a total occlusion was observed in 1. At 3 month follow-up, 41% of the dyssynergic segments improved. The sensitivity, specificity and accuracy for late wall motion improvement was 61, 89 and 77% for low-dose dobutamine echocardiography and, respectively, 76, 45 and 58% for rest-redistribution thallium SPECT. Tissue viability was detected in 65 and 31% of dyssynergic segments by rest-redistribution thallium SPECT and low-dose dobutamine echocardiography, respectively (p < 0.001). The agreement between the two techniques was 48%. CONCLUSIONS: Low-dose dobutamine echocardiography is more accurate than rest-redistribution thallium SPECT for predicting 3 month wall motion improvement in patients with acute anterior myocardial infarction, mainly due to its significantly better specificity.