Comparison of angiographic estimation and invasive hemodynamic measurement of the significance of non-infarct-related residual stenoses in ST-elevation myocardial infarction patients.

Introduction: Up to 50% of patients with ST elevation myocardial infarction (STEMI) have ≥ 50% stenosis in a major non-infarct-related artery. Several studies have evaluated the prognostic value of the completion of revascularization with overall inconclusive results. Selection of the stenoses was based on the angiographic evaluation, invasive hemodynamic measurement or the combined approach. It is unknown whether such a selection provides correlation of comparable patient groups. Material and methods: We enrolled 51 patients (62.7 ±10.2 years) with acute STEMI and at least one residual (50-90%) stenosis in a non-infarct-related major coronary artery (excluding left main coronary artery). Overall 65 stenoses (67.9 ±10.7%) were evaluated angiographically following primary percutaneous coronary intervention and the hemodynamic significance was estimated with respect to the stenosis severity, caliber of the arterial segment, localization of the stenosis (proximity) as well as the estimated size of the supplied vascular territory. During subsequent hospitalization, invasive measurement of the hemodynamic significance using fractional flow reserve (FFR) was performed to guide the final revascularization strategy (FFR value of ≤ 0.80 considered significant). Results: Based on angiographic evaluation, a total of 44 stenoses would be recommended for treatment, whereas only 31 stenoses were revascularized based on FFR measurement. Moreover, visual evaluation and hemodynamic measurement were discrepant in 27 of 65 (41.5%) stenoses. Conclusions: We observed a weak correlation between visual angiographic evaluation and invasive hemodynamic measurement. More stents would be implanted based on angiographic evaluation compared to FFR measurement.

Combination of myocardial perfusion imaging, left ventricle function parameters and coronary artery calcium score in risk evaluation in patients with diabetes mellitus.

OBJECTIVE: Myocardial perfusion imaging (MPI) can be challenging in some cases of multi vessel involvement. Our aim was to examine specific group of patients with diabetes mellitus (DM), who did not have significant reversible ischaemia diagnosed on perfusion study itself, and asses additional value of functional parameters obtained from gated acquisition and added information from coronary artery calcium score (CACS). SUBJECTS AND METHODS: One hundred and seventy eight patients with a history of DM, with summed difference score (SDS)≤1, were included in the study. All patients underwent gated acquisition with recording of functional parameters and CACS evaluation. During the follow-up, cardiac events (CE) were recorded. RESULTS: During the median follow-up of 20.3 months there were 23 CE encountered. Optimal cut-off value for CACS to predict CE was found at 1427, higher values were significantly related to CE (P<0.001). Low stress left ventricular ejection fraction (LVEF) <45% and induced stress LVEF drop for 5% were also more frequent in CE group (P=0.001, P=0.008). Multivariable Cox analysis revealed low stress LVEF (P=0.001, HR=4.48, 95%CI 1.79-11.22), stress induced LVEF drop (P=0.017, HR 3.13, 95%CI 1.22-8.01) and high CACS (P<0.001, HR 10.52, 95%CI 4.32-25.63) as significant predictors of CE. CONCLUSION: Low stress LVEF under 45%, post-stress LVEF drop for more than 5% and CACS more than or equal to 1427 are significant predictors of CE in patients with DM, who did not have reversible ischemia detected on MPI single photon emission computed tomography (SPECT).

Assessment of left ventricular volumes and ejection fraction using ultra-low-dose thallium-201 SPECT on a CZT camera: a comparison with magnetic resonance imaging.

BACKGROUND: Cadmium-Zinc-Telluride (CZT) technology allows use of low activities of radiopharmaceuticals. The aim was to verify the values of left ventricular volume parameters, obtained via ultra-low-dose thallium Single Photon Emission Computed Tomography (SPECT) using a CZT camera. METHODS AND RESULTS: Forty-five patients referred for an assessment of myocardial perfusion or viability imaging were examined using CZT-SPECT and 1.5 T magnetic resonance (MRI) scanner. The ultra-low-dose protocol with 0.5 Mbq 201-Tl per kg of body weight was used. The values of end-systolic (ESV) and end-diastolic volumes (EDV), left ventricular ejection fraction (EF) and myocardial mass (MM) were assessed using both techniques. A very good correlation was found between the EF, ESV, and EDV values assessed with CZT-SPECT and cardiac magnetic resonance MRI; the Pearson coefficients were 0.86, 0.95, and 0.91, respectively. A moderate correlation was found for myocardial mass, r = 0.57. Compared to MRI, SPECT systematically overestimated ESV and MM, while it underestimates the EF, with P ≤ .001 in all cases. There was no difference in EDV estimation. CONCLUSIONS: Left ventricular volumes and ejection fraction assessed via ultra-low-dose CZT-SPECT showed very good correlation with the values obtained by MRI. A moderate correlation was found for myocardial mass.

Additional value of the coronary artery calcium score in patients for whom myocardial perfusion imaging is challenging.

BACKGROUND Determination of prognosis based on ischemia detection, using single­photon emission computed tomography myocardial perfusion imaging (SPECT­MPI), can be challenging in patients with multiple affected coronary arteries. AIMS The aim of the study was to examine the outcomes of SPECT­MPI combined with the coronary artery calcium score (CACS) to identify predictors of adverse cardiac events (ACEs) in patients for whom ischemia detection may be difficult using SPECT­MPI. METHODS The study group included 195 patients with a history of chronic kidney disease, suspected ischemic cardiomyopathy, or left bundle branch block. All patients underwent SPECT­MPI and CACS evaluation. During the follow­up, ACEs were recorded. Perfusion and functional parameters as well as the CACS were analyzed to find the predictors of ACEs. RESULTS The ACEs were recorded in 58 individuals (29.7%) and were significantly associated with ischemia (P <0.001), abnormal functional parameters (P = 0.04), and higher CACSs (P <0.001). The optimal cutoff value of the CACS to predict an ACE was 530. Cox proportional hazards models revealed that age, mild and severe ischemia, functional abnormalities, and a CACS of 530 or higher were significant predictors of ACEs. In the subgroup of individuals without ischemia, a CACS of 530 or higher was significantly associated with poor outcome, while we recorded only 3 ACEs in these patients when the CACS was lower than 530. CONCLUSIONS The addition of the CACS to SPECT­MPI improves the identification of patients at higher risk for ACEs, even in individuals for whom SPECT­MPI is challenging.

The prognostic value of ultra low-dose thallium myocardial perfusion protocol using CZT SPECT.

The purpose of this study was to assess the prognostic value of ultra-low dose thallium myocardial perfusion imaging. Three hundred and sixty-six patients (245 men) underwent ultra-low dose stress-redistribution imaging on CZT SPECT camera GE Discovery NM 530c. The stress test was performed by bicycle ergometry or regadenoson injection. The activity of 0.5 MBq (0.014 mCi) Tl-201 chloride per kilogram of body weight was administered. The stress images were acquired immediately and redistribution images were taken after 3 h. Patient follow-up was focused on combined end-point (death, myocardial infarction, unstable angina, revascularization and hospitalization for heart failure). Data analysis was performed from hospital database, with a mean period 23 months. Patients with revascularization within 1 month after SPECT was excluded as revascularization for diagnosis. Ischaemia on SPECT was found in 72 patients, 294 patients were without ischaemia. In patients with ischaemia there were 21 (29.2%) subjects with cardiac events, and 23 (7.9%) in patients without ischaemia (HR 4.15, 95% CI 2.30-7.51, p < 0.0001). Ultra-low dose thallium perfusion imaging using CZT camera provides very good prognostic results in assessment of myocardial ischaemia.

Possitive correlation between adipocyte fatty acid-binding protein and epicardial fat in patients with a family history of cardiovascular disesase.

BACKGROUND: Adipocyte fatty acid-binding protein (A-FABP) is a promising link between metabolic syndrome and atherosclerosis. Epicardial fat (EPI) is an independent risk factor for cardiovascular disease (CVD). OBJECTIVE: The aim of this pilot study was to evaluate the correlation between EPI and A-FABP in asymptomatic patients with a family history of CVD. METHODS: 59 subjects (39 males) (median = 54 years old) were enrolled in the study and their EPI thickness and A-FABP levels were assessed. RESULTS: EPI was found in 46 patients (77.9%). There were positive correlations between EPI and A-FABP (r=0.336; P=0.010), age (r=0.526; P<0.001), fibrinogen (r=0.304; P=0.023) and systolic blood pressure (r=0.279; P=0.034). A positive correlation was found between EPI and A-FABP in a subgroup of overweight and obese patients (0.389; P=0.041, 0.407; P=0.004) and in the subgroup of patients with excluded CVD (r=0.368; P=0.006). CONCLUSIONS: We found a positive correlation between EPI and A-FABP in a group of patients with a family history of CVD and in subgroups of overweight and obese patients.

Feasibility of ultra low-dose thallium stress-redistribution protocol including prone imaging in obese patients using CZT camera.

High efficiency cadmium-zinc-telluride (CZT) cameras provide an opportunity to lower the injected activities of radiopharmaceuticals for single photon emission tomography (SPECT) myocardial perfusion imaging (MPI). The limits for reducing activities of thallium have not been determined, particularly in obese patients. After an injection of 0.7 megabecquerel (MBq) of thallium/kg, we collected an average 1.5 million counts for the 10-min acquisition in a pilot cohort of ten patients. After extrapolation, we reduced the administered activity to 0.5 MBq/kg to obtain the expected 1 million counts. We studied the image quality in 124 patients (86 men, 43 obese with body mass index over 30 kg/m2) referred for MPI. The quality of images was assessed by a number of recorded counts and visually by a four-grade scale (one-poor quality, four-excellent quality). In non-obese and obese patients, the average number of recorded counts was 1.1 vs. 1.07 million counts for the 10-min stress acquisition, 1.04 vs. 1.06 million counts for the 13-min rest acquisition, and the average quality score was 3.97 vs. 3.90, respectively (p = NS).The mean administered activity was 39.2 ± 7 MBq for non-obese and 48.7 ± 6 for obese patients (p < 0.0001), and the calculated effective dose was 4.0 ± 0.7 and 4.9 ± 0.6 mSv respectively (p < 0.0001). The ultra-low-dose thallium stress-redistribution protocol, including post-stress prone imaging, provides good quality of images with a low radiation burden, even in obese patients.

Risk factors of atherosclerosis during systemic therapy targeting vascular endothelial growth factor.

The aim of the present study was to examine the changes in intima-media thickness (IMT) and myocardial perfusion in association with other laboratory risk factors for atherosclerosis in patients treated with therapy that targeted vascular endothelial growth factor (VEGF). IMT, myocardial perfusion and laboratory risk factors of atherosclerosis were studied in 58 patients with metastatic colorectal carcinoma or metastatic renal cell carcinoma prior to and at 3-monthly intervals during anti-VEGF treatment. Compared with the pretreatment IMT, the results indicated that the IMT was consistently increased during therapy in the two patient groups. Patient blood pressure and concentration of troponin T increased transiently. An increase in the concentration of high-density lipoprotein cholesterol and decrease in the concentrations of C-reactive protein and homocysteine were also observed. Novel myocardial ischemia was evident in individual patients. In conclusion, anti-VEGF therapy affects the laboratory risk factors of atherosclerosis and results in an acceleration of atherosclerosis, as demonstrated by increased IMT.

Reconstruction of massive post-sternotomy defects with allogeneic bone graft: four-year results and experience using the method.

OBJECTIVES: Deep sternal wound infection poses a serious problem in cardiac surgery, with an up to 40% risk of mortality. Massive loss of sternum bone tissue and adjacent ribs results in major chest wall instability causing respiratory insufficiency and defects of soft tissue healing. Proposals for managing the situation have been published but the complexity of the issue precludes unequivocal resolution. Capitalizing on orthopaedic experience, we used allogeneic bone graft of sternum as a viable option. METHODS: We performed the transplantation of allogeneic bone graft in 10 patients. In 9 cases, an allograft of sternum was used and in 1 case an allograft of calva bone. After the primary cardiac surgery, a massive post-sternotomy defect of the chest wall had developed in all 10 patients. Vacuum wound drainage was applied in the treatment of all patients. To stabilize the transverse, titanium plates were used. Bone allograft was prepared by the official Tissue Centre. Crushed allogeneic spongy bone was applied to reinforce the line of contact of the graft and the edges of residual skeleton. In 9 cases, the soft tissue was closed by direct suture of mobilized pectoral flaps. In 1 case, V-Y transposition of pectoral flap was performed. RESULTS: In 6 cases, healing of the reconstructed chest wall occurred without further complications. In 3 cases, additional re-suture of the soft tissues and skin in the lower pole of the wound was necessary. Excellent chest wall stability along with the adjustment of respiratory insufficiency and good cosmetic effect was achieved in all cases. In 1 case, severe concomitant complications and no healing of the wound resulted in death within 6 months after the reconstruction. Median follow-up of all patients in the series was 14.1 months (1-36 months). In 4 patients, scintigraphy of the chest wall was performed. CONCLUSIONS: Our existing results show that allogeneic bone graft transplantation is a promising and easily applied method in the management of serious tissue loss in sternal dehiscence with favourable functional and cosmetic effects. The relatively small number of patients with such severe healing complications of sternotomy however puts critical limits to a more detailed comparison with other practices and evaluation of long-term results.

Prognostic value of myocardial perfusion imaging and coronary artery calcium measurements in patients with end-stage renal disease.

OBJECTIVE: Coronary artery disease (CAD) is highly prevalent in patients with end-stage renal disease (ESRD), owing to clustering of traditional and uremic-specific risk factors. However, in this population asymptomatic course of CAD is common and it has been reported that myocardial perfusion imaging (MPI) with single-photon emission tomography (SPET) has lower sensitivity. In the current study, we assessed the value of MPI gated-SPET and its combination with coronary artery calcium (CAC) score measurements in risk stratification of ESRD patients. MATERIALS AND METHODS: MPI gated-SPET was performed with dual-headed SPET camera and CAC score measured by multi-detector computed tomography (MDCT) system.There were tested 77 ESRD individuals. During the follow-up study, cardiac events (CE) defined as cardiac death or nonfatal myocardial infarction (MI) or the necessity for coronary revascularization were recorded. Univariate and stepwise multivariable Cox proportional hazards-models were used to identify the predictors of CE. RESULTS: Eighteen CE were recorded during the follow-up. They were significantly associated with higher summed stress scores on MPI, higher percentage of ischaemic myocardium, higher occurrence of defects in multiple territories and higher CAC score (all with P<0.05). Univariate Cox proportional hazard-models showed that severe perfusion abnormalities as well as CAC score ≥1000 were significantly associated with cardiac events (P<0.0001, P=0.0056). In stepwise Cox proportional hazards-models considering age, gender, history of diabetes mellitus, post-stress left ventricular stunning, the degree of perfusion abnormality and CAC score, only severe perfusion abnormalities and CAC score ≥1000 were independent predictors of CE. There was no CE in patients with normal perfusion, normal function and zero CAC score. CONCLUSION: This study suggests that combined evaluation of MPI and CAC can predict the outcome in ESRD individuals, while severe perfusion abnormality on gated-SPET and high CAC score ≥1000 are predictors of future cardiac events.

Diagnosis of high-risk patients with multivessel coronary artery disease by combined cardiac gated SPET imaging and coronary calcium score.

OBJECTIVE: The added value of coronary artery calcium (CAC) to SPET for identification of multivessel CAD has not been studied yet. The aim of this original study was to investigate CAC as an adjunct to gated single photon emission tomography (GSPET) in the detection of multivessel coronary artery disease (CAD). SUBJECTS AND METHODS: The study group consisted of 164 prospectively recruited patients without known CAD-123 (75%) men and 60 (37%) women, having diabetes type II, renal insufficiency, left ventricular dilatation and other cardiac problems (arrhythmia, necessity of pharmacological stress test, etc.). The mean age of these patients was 61±12 years (range 34-85 years). All these patients underwent GSPET imaging, CAC score measurement, and coronary angiography. The percentage of ischaemic myocardium, stress and rest left ventricular ejection fraction (LVEF), and transient ischaemic dilation (TID) ratio were measured. RESULTS: Patients with multivessel CAD had more frequently reversible defects in multiple territories, severe ischaemia ≥10% of the left ventricle, stress worsening of the LVEF ≥5%, TID ratio ≥1.17, and CAC score >1000. In the detection of multivessel CAD, the sensitivity of combined assessment of perfusion, function, and CAC (i.e., multiple and/or ≥10% ischaemia, and/or worsening of the LVEF ≥5%, and/or TID ratio ≥1.17, and/or CAC score >1000) was significantly higher than the sensitivity of perfusion alone or perfusion and function alone (81% vs. 55% and 65%, respectively, P<0.05). Sensitivity of only CAC was low (41%). CONCLUSION: Sensitivity of combined assessment of myocardial perfusion, function, and CAC was significantly higher than sensitivity of perfusion alone or perfusion and function alone, suggesting better identification of high-risk patients with CAD.

Brain metastases of parathyroid carcinoma: Review of the literature and a case report.

BACKGROUND: Parathyroid carcinoma is a rare tumor typically presenting with marked elevations of serum calcium concentrations and associated renal and skeletal symptoms. Parathyroid carcinoma grows slowly, but may recur in regional lymph nodes, and, in about 25% of patients, metastasizes to the lungs. METHOD: Description of a new case and review of the literature. RESULTS: We present here a patient with parathyroid carcinoma that had aggressive biological behavior with synchronous lung metastases and manifestation of brain metastases 18 month after the initial diagnosis and review earlier reports on this rare presentation. These metastases could be detected with [(18)F] fluorodeoxyglucose positron-emission tomography/computed tomography as well as with (99m)technetium-sestamibi scan. CONCLUSIONS: Except for surgery in case of isolated solitary metastases, therapeutic options in patients with brain metastases of parathyroid carcinoma are currently very limited.

Successful three-year outcome in a patient with allogenous sternal bone graft in the treatment of massive post-sternotomy defects.

INTRODUCTION: Deep sternal wound infection is a life-threatening complication of longitudinal median sternotomy with extensive loss of sternal bone tissue and adjacent ribs. Wound dehiscence cases with no loss of bone tissue can be resolved via osteosynthesis using titanium plates. Unfortunately, this cannot be used in cases of massive bone tissue loss defects due to insufficient support for fixing the plate material caused by missing bone surface which increasing the risk of osteosynthesis failure. We describe the treatment outcome of sternal dehiscence with massive bone tissue loss defects using an allogenous sternal bone graft. CASE PRESENTATION: A 62 year old diabetic female was operated for serious sternotomy dehiscence after surgery for aortic valve replacement. There was bone tissue loss and complications. We used allogenous sternal bone graft to close the wound. To monitor the healing of the graft, we performed SPECT/CT examinations of anterior chest wall. We describe the successful healing of the graft with the reduction of defects in osteoblastic activity by 42% 21 months after the graft implantation. The wound was found to be healed on all examinations, The chest wall is stable and the patient reports a good life quality. DISCUSSION: An allogenous bone transplant contains no vital bone marrow cells, which eliminates immuno-genetic graft rejection by the patient. Significant osteoblastic activity was thus registered, especially in places where crushed spongy bone had been applied. CONCLUSIONS: Transplantation of allogenous bone graft sternum in our experience is the best option for treating extensive post-sternotomy defects.

Prognostic value of stress-only and stress-rest normal gated SPECT imaging: higher incidence of cardiac hard events in diabetic patients who underwent full stress-rest imaging.

BACKGROUND: The European procedural guidelines for cardiac gated SPECT imaging demonstrate considerable variability in recommended administered radiopharmaceutical activity and imaging protocols. This study compared stress-only and stress-rest protocols to evaluate the safety of stress-only imaging, and to identify characteristics of patients who need full stress-rest imaging. METHODS: Patients referred for a chest pain were scheduled for stress-rest gated SPECT imaging. If the stress images were interpreted as normal according to the perfusion and left ventricular function, the examination of patients was finished and patients did not undergo the rest imaging. A total number of 1063 patients was included (mean age 61 ± 11 years). These patients have been followed for hard cardiac events, i.e. cardiac deaths or nonfatal myocardial infarction. RESULTS: During a follow-up of 3.2 ± 2.5 years, hard events occurred in 12 patients with normal SPECT and 59 with abnormal SPECT had hard events (0.7 vs. 3.6% /year, P < 0.001). Among the 536 patients with normal study, there was no significantly lower incidence of hard events in the subgroup of patients with stress-only imaging (0.6 vs. 0.8% /year, P = 0.641). Diabetes mellitus was an independent predictor of hard events in patients with normal SPECT (1.3 vs. 0.5%/year, P < 0.001). We found a higher incidence of hard events in diabetic patients with normal study with the necessity of full stress-rest imaging in comparison with those with stress-only imaging (1.7 vs. 0.7% /year, P < 0.001). CONCLUSIONS: Our results support the good prognosis of normal stress-only study. Diabetes mellitus was an independent predictor of hard events in patients with normal SPECT. Diabetic patients with normal results who required additional rest imaging had significant adverse outcome.

Myocardial perfusion imaging parameters: IQ-SPECT and conventional SPET system comparison.

Technological advancement in hardware and software development in myocardial perfusion imaging (MPI) leads to the shortening of acquisition time and reduction of the radiation burden to patients. We compared semiquantitative perfusion results and functional parameters of the left ventricle between new dedicated cardiac system with astigmatic collimators called IQ-SPECT (Siemens Medical Solutions, USA) and conventional single photon emission tomography (SPET) system equipped with standard low energy high resolution collimators. A group of randomly selected 81 patients underwent consecutively the MPI procedure on IQ-SPECT and on conventional SPET systen, both without attenuation correction. The summed scores and the values of the functional parameters of the left ventricle: ejection fraction (EF), end-systolic and end-diastolic volumes (ESV, EDV) received from the automatic analysis software were compared and statistically analyzed. Our results showed that summed scores values were significantly higher for the IQ-SPECT system in comparison to the conventional one. Calculated EF were significantly lower for IQ-SPECT, whereas evaluated left ventricular volumes (LVV) were significantly higher for this system. In conclusion, we recorded significant differences in automatically calculated semiquantitative perfusion and functional parameters when compared uncorrected studies obtained by the IQ-SPECT with the conventional SPET system.

Nuclear medicine training and practice in the Czech Republic.

Nuclear medicine in the Czech Republic is a full specialty with an exclusive practice. Since the training program was organized and structured in recent years, residents have had access to the specialty of nuclear medicine, starting with a two-year general internship (in internal medicine or radiology). At present, nuclear medicine services are provided in 45 departments. In total, 119 nuclear medicine specialists are currently registered. In order to obtain the title of Nuclear Medicine Specialist, five years of training are necessary; the first two years consist of a general internship in internal medicine or radiology. The remaining three years consist of training in the nuclear medicine specialty itself, but includes three months of practice in radiology. Twenty-one physicians are currently in nuclear medicine training and a mean of three specialists pass the final exam per year. The syllabus is very similar to that of the European Union of Medical Specialists (UEMS), namely concerning the minimum recommended numbers for diagnostic and therapeutic procedures. In principle, the Czech law requires continuous medical education for all practicing doctors. The Czech Medical Chamber has provided a continuing medical education (CME) system. Other national CMEs are not accepted in Czech Republic.

Implant site development in the distal region of the mandible: bone formation and its stability over time.

INTRODUCTION: The purpose of this study was to determine the dimensional changes that occur in the alveolar ridge of patients upon distalization of the mandibular first premolars into the place of congenitally missing mandibular second premolars. The amount of bone formation that accompanied orthodontic treatment and the long-term stability of the new bone were assessed. METHODS: Fifty-five patients were included in the study, representing 71 congenitally missing mandibular second premolars. The dimensional changes were evaluated by comparing the dental stone casts and panoramic radiographs taken at treatment initiation (T1) and end (T2) and at follow-ups of 2 years (T3A) and 5 years (T3B). RESULTS: During the treatment period (T1-T2), the alveolar ridge width increased by an average of 28.5%, and the height increased by an average of 1.1 mm. During the retention periods (T2-T3A, T2-T3B), the alveolar ridge decreased by an average of 4.2%, but the height decreased only slightly (by an average of 0.07 mm). CONCLUSIONS: Orthodontic tooth movement created a significant amount of new bone that was stable in both the horizontal and vertical directions.