A randomized, double-blind, placebo-controlled study assessing the safety and tolerability of regadenoson in subjects with asthma or chronic obstructive pulmonary disease

Background

Adenosine receptor stress agents for myocardial perfusion imaging (MPI) may cause A_2B and/or A₃ receptor-mediated bronchoconstriction, of particular concern to physicians testing patients with asthma or chronic obstructive pulmonary disease (COPD).

Methods

A Phase 4, randomized, double-blind study (NCT00862641) assessed the safety of the selective A_2A receptor agonist, regadenoson, compared with placebo in subjects with asthma or COPD who represented likely candidates for MPI.

Results

Overall, 356 and 176 subjects with asthma and 316 and 151 subjects with COPD received regadenoson and placebo, respectively. The percentage of subjects experiencing a >15% decrease in FEV₁ from baseline to any assessment up to 24 hours post-baseline was not statistically significantly different between the regadenoson and the placebo groups in the asthma or COPD stratum. Dyspnea, the most frequent respiratory adverse event, occurred with higher incidence (P?<?.0001) in the regadenoson group than the placebo group in the asthma (10.7% vs 1.1%) and COPD (18.0% vs 2.6%) strata. No subjects experienced severe bronchoconstriction, although the occurrence of such reactions with adenosine receptor agonists cannot be ruled out, such that caution is advised.

Conclusions

This information may be helpful to physicians selecting a pharmacologic stress agent for MPI in patients with asthma or COPD.     

Regadenoson in Europe: first-year experience of regadenoson stress combined with submaximal exercise in patients undergoing myocardial perfusion scintigraphy

Purpose

Regadenoson was approved for clinical use in Europe in 2011. Since then, it has become the default form of stress at our institution. We have assessed the side-effect profile and tolerability of regadenoson in patients undergoing clinically indicated myocardial perfusion scintigraphy between July 2011 and July 2012.

Methods

Clinical, stress and imaging data were recorded prospectively. Symptoms during stress were recorded and defined as mild, moderate or severe. An adverse event was defined as any symptom that persisted for more than 30 min or that required investigation or treatment.

Results

Of 1,764 consecutive patients, 1,581 (90 %) received regadenoson combined with submaximal exercise unless contraindicated. Symptoms were common (63 %) but transient and well-tolerated. The severity of symptoms was recorded in most patients as mild (84 %). Dyspnoea (36 %) and chest discomfort (12 %) were the commonest side effects. Adverse events were reported in eight patients (0.5 %), thought to be vasovagal in seven of these. All patients recovered fully without sequelae. There were no deaths, myocardial infarction or hospital admissions. Regadenoson stress was performed in 206 patients (12 %) with asthma or chronic obstructive pulmonary disease (COPD) without bronchospasm or any other major side effect.

Conclusion

We studied the symptom profile of regadenoson in the largest European cohort to date. Regadenoson combined with submaximal exercise was well tolerated, notably also in patients with asthma or COPD. The majority of regadenoson-related adverse events were vasovagal episodes without sequelae.     

Safety of regadenoson in patients with end-stage liver disease

Background

Regadenoson is a selective A_2A receptor agonist that is used for vasodilator stress myocardial perfusion imaging (MPI). Since the drug is partially metabolized by the liver, its safety in patients with end-stage liver disease (ESLD) needs to be determined.

Methods and Results

We studied 168 consecutive patients with ESLD who had regadenoson stress gated single photon emission computed tomography MPI between January 2008 and March 2010 before planned orthotopic liver transplantation and compared the hemodynamic responses and safety profile to 168 control patients. There were 72 women (43%) in ESLD versus 87 (52%) in the control group (P = .1). The patients with ESLD were younger (58 ± 7 vs 62 ± 12 years, P = .0002), but more likely to be Caucasians (P = .002). The MPI images were normal in 161 patients (96%) in each group. The left ventricular ejection fraction was 72 ± 10% in ESLD and 66 ± 11% in the control patients (P = .0001). The heart rate increase in response to regadenoson was lower in patients with ESLD than in the control group (16 ± 11 vs 23 ± 16 bpm, P = .0001), but the changes in systolic and diastolic blood pressures were similar (?9 ± 12 vs ?11 ± 14 mmHg and ?6 ± 8 vs ?7 ± 10 mmHg, respectively, P = NS). There were no deaths or medication-related adverse events that required hospitalization in either group within 30 days of the study.

Conclusion

This is the first study to document the tolerability and safety profile of regadenoson in patients with ESLD.     

The impact of regimented aminophylline use on extracardiac radioisotope activity in patients undergoing regadenoson stress SPECT myocardial perfusion imaging: A substudy of the ASSUAGE trial

Background

In patients undergoing regadenoson stress SPECT myocardial perfusion imaging (MPI), the impact of the regimented administration of aminophylline on the cardiac-to-extracardiac photon activity ratio is unknown.

Methods

This is a substudy of the ASSUAGE trial (NCT01250496); a double-blinded, randomized, placebo-controlled clinical trial which investigated the attenuation of regadenoson-related adverse effects using 75 mg of intravenous aminophylline vs placebo, administered 90 seconds following ^99mTc-tetrofosmin injection in patients undergoing regadenoson stress SPECT-MPI. In subjects with normal MPI enrolled in the trial, we sampled from the antero-posterior planar projection of the post-stress scintigraphic data the mean photon activity in the myocardium, liver, bowel, and lungs. The mean cardiac-to-extracardiac activity ratios were compared between patients randomized to aminophylline vs placebo.

Results

We studied 158 eligible subjects, randomized to receive aminophylline (n = 86) or placebo (n = 72). The means of photon activity ratios of the heart-to-liver, heart-to-bowel, heart-to-lungs, inferior wall of the heart-to-liver, and inferior wall of the heart-to-bowel were not statistically different between those who received aminophylline vs placebo (P values > .30). Only the time lapse between stress ^99mTc-tetrofosmin injection and stress SPECT acquisition independently correlated with higher heart-to-liver and heart-to-bowel activity ratios (P values ≤ .01). Patients’ body mass index independently correlated with lower heart-to-lung ratio (P = .009).

Conclusion

The regimented intravenous aminophylline use following regadenoson stress does not significantly improve the cardiac-to-extracardiac photon activity ratio in patients undergoing regadenoson stress ^99mTc-tetrofosmin SPECT-MPI.     

A strategy of symptom-limited exercise with regadenoson-as-needed for stress myocardial perfusion imaging: A randomized controlled trial

Background

Ambulatory patients with uncertain functional capacity may benefit from combined exercise and vasodilator stress protocols for myocardial perfusion imaging (MPI). The safety and MPI image quality with regadenoson administered during symptom-limited exercise have not been prospectively evaluated.

Methods and Results

A total of 140 patients (mean age 61 years, 48% female) referred for exercise with vasodilator stress MPI were randomized 2:1 to a strategy of exercise with regadenoson-as-necessary (Ex-Reg, n = 96) or dipyridamole with exercise (Dip-Ex, n = 44) after Duke Activity Status Index (DASI) scoring (median score 28 vs 24, P = .09). Ex-Reg subjects commenced treadmill exercise and regadenoson was administered only if the subject was unable to reach standard endpoints. Dip-Ex subjects received dipyridamole prior to symptom-limited exercise. Hemodynamics were recorded throughout. Subjects completed symptom questionnaires and MPI image quality was assessed by blinded read. Ex-Reg subjects were more likely to achieve ≥85% age-predicted maximum heart rate than Dip-Ex subjects (57% vs 32%, P < .01). Only 50% of subjects meeting inclusion criteria and randomized to Ex-Reg required regadenoson and none had symptomatic hemodynamic changes. Severe side effects or adverse events occurred in 16% of Ex-Reg and 24% of Dip-Ex subjects (P = .12). MPI image quality was “good” or “excellent” in 88% of Ex-Reg subjects and 86% of Dip-Ex subjects (P = .33).

Conclusion

A strategy of exercise with regadenoson-as-needed for MPI offers similar safety and side effect profile with similar image quality compared to dipyridamole with exercise, with reduced pharmaceutical use.     

Safety and feasibility of adjunctive regadenoson injection at peak exercise during exercise myocardial perfusion imaging: The Both Exercise and Regadenoson Stress Test (BERST) trial

Background

The data existing in the literature regarding the safety of using regadenoson with symptom-limited exercise are limited, which motivated the authors to undertake this randomized study.

Methods

We offered patients scheduled to undergo vasodilator stress nuclear myocardial perfusion imaging the opportunity to exercise instead. Patients who failed to reach target heart rate (THR) were randomized to (1) receive regadenoson at peak exercise or (2) stop exercise and receive regadenoson at rest. Patients who reached THR received a standard Tc-99m sestamibi injection with no regadenoson.

Results

200 patients were included (66% male, mean age 52.5 ± 13.6). 125 patients (62%) reached THR with exercise alone. All stress protocols were well tolerated, and there were no significant adverse events. There were no statistically significant differences in the extent of perfusion abnormalities, image quality, or rate of referral to cardiac catheterization within 60 days between the groups. In fully adjusted logistic regression models, beta-blocker use and diabetes remained significant univariate predictors of failure to reach THR (OR 0.21, 95% CI 0.1-0.5, P < .0001, OR 0.34, 95% CI 0.2-0.7, P = .004, respectively).

Conclusions

A protocol combining regadenoson at peak exercise in patients unable to reach THR with exercise is feasible, well-tolerated, and yields comparable imaging results to a standard regadenoson injection at rest. In addition, pharmacologic stress testing may be over-ordered in current clinical practice, as patients referred for such testing were often able to exercise.     

Attenuation of the side effect profile of regadenoson: A randomized double-blinded placebo-controlled study with aminophylline in patients undergoing myocardial perfusion imaging. “The ASSUAGE trial”

Background

It is unknown whether the standardized intravenous aminophylline administration following regadenoson-stress can prevent the gastrointestinal and other adverse effects associated with regadenoson.

Methods

In a randomized, double-blinded, placebo-controlled clinical trial we compared the frequency and severity of regadenoson adverse effects in those who received 75?mg of intravenous aminophylline versus a matching placebo administered 2?minutes after regadenoson or 90?seconds post-radioisotope injection.

Results

248 patients [44.8% women, mean age 62.2 (±13.3) years] were randomized to receive aminophylline (124) or placebo (124). In the aminophylline arm, there was 50% reduction in the incidence of the primary endpoint of diarrhea and abdominal discomfort [11 (8.9%) vs 22 (17.7%), P?=?.04] and 70% reduction in the incidence of diarrhea [4 (3.2%) vs 13 (10.5%), P?=?.02]. Additionally, aminophylline use was associated with 34% reduction in the secondary endpoint of any regadenoson adverse effects [55 (44.4%) vs 83 (66.9%), P?<?.001] and 71% reduction in headache [9 (7.3%) vs 31 (25%), P?<?.001]. The stress protocol was better tolerated in the aminophylline group (P?=?.007). The quantitative summed difference score was similar in both study groups (P?=?.92). There were no excess adverse events in the aminophylline arm.

Conclusions

This trial supports the routine administration of IV-aminophylline to reduce the frequency and severity of adverse effects associated with regadenoson-stress.     

The safety and tolerability of regadenoson in patients with end-stage renal disease: The first prospective evaluation

Background

There has not been any prospective evaluation of the safety and tolerability of regadenoson (REG)-stress in patients with end-stage renal disease (ESRD).

Methods

From the pooled database of two identically designed randomized, double-blinded, placebo-controlled clinical trials, ASSUAGE and ASSUAGE-CKD (IV-aminophylline vs placebo following REG-stress), we extracted the placebo-treated subjects to form 2 study groups: ESRD (dialysis or GFR < 15 mL/minute/1.73 m²) and control (GFR ≥ 30). The incidence of REG adverse effects and the hemodynamic and ECG responses to REG-stress were compared.

Results

We identified 146 ESRD subjects and 97 controls. There was no significant difference in the incidence of the composite of any REG adverse effect [ESRD 108 (74%) vs control 73 (75%), P = .82]. ESRD patients seem to have excess incidences of diarrhea [42 (29%) vs 14 (14%), P = .009] and fewer events of dizziness [28 (19%) vs 43 (44%), P < .001]. There were no serious adverse events in either group. There was no significant difference in the incidence of ST-segment deviation, tachyarrhythmias, atrioventricular block, or hypotension.

Conclusion

This is the first prospective study to confirm the safety and tolerability of REG in patients with ESRD.     

Diagnostic accuracy of 128-slice dual-source CT coronary angiography: a randomized comparison of different acquisition protocols

Objectives

To compare the diagnostic performance and radiation exposure of 128-slice dual-source CT coronary angiography (CTCA) protocols to detect coronary stenosis with more than 50 % lumen obstruction.

Methods

We prospectively included 459 symptomatic patients referred for CTCA. Patients were randomized between high-pitch spiral vs. narrow-window sequential CTCA protocols (heart rate below 65 bpm, group A), or between wide-window sequential vs. retrospective spiral protocols (heart rate above 65 bpm, group B). Diagnostic performance of CTCA was compared with quantitative coronary angiography in 267 patients.

Results

In group A (231 patients, 146 men, mean heart rate 58?±?7 bpm), high-pitch spiral CTCA yielded a lower per-segment sensitivity compared to sequential CTCA (89 % vs. 97 %, P?=?0.01). Specificity, PPV and NPV were comparable (95 %, 62 %, 99 % vs. 96 %, 73 %, 100 %, P?>?0.05) but radiation dose was lower (1.16?±?0.60 vs. 3.82?±?1.65 mSv, P?<?0.001). In group B (228 patients, 132 men, mean heart rate 75?±?11 bpm), per-segment sensitivity, specificity, PPV and NPV were comparable (94 %, 95 %, 67 %, 99 % vs. 92 %, 95 %, 66 %, 99 %, P?>?0.05). Radiation dose of sequential CTCA was lower compared to retrospective CTCA (6.12?±?2.58 vs. 8.13?±?4.52 mSv, P?<?0.001). Diagnostic performance was comparable in both groups.

Conclusion

Sequential CTCA should be used in patients with regular heart rates using 128-slice dual-source CT, providing optimal diagnostic accuracy with as low as reasonably achievable (ALARA) radiation dose.

Key Points

? 128-slice dual-source CT coronary angiography offers several different acquisition protocols. ? Randomized comparison of protocols reveals an optimal protocol selection strategy. ? Appropriate CTCA protocol selection lowers radiation dose, while maintaining high quality. ? CTCA protocol selection should be based on individual patient characteristics. ? A prospective sequential protocol is preferred for CTCA.     

Regadenoson pharmacologic rubidium-82 PET: A comparison of quantitative perfusion and function to dipyridamole

Background

Dipyridamole is used for stress ⁸²rubidium chloride (⁸²RbCl) PET because of its long hyperemic duration. Regadenoson has advantages of a fixed dose and favorable symptom profile, but its mean maximal hyperemia is only 2.3 minutes. To determine its suitability for ⁸²RbCl PET, we imaged subjects using a regadenoson protocol based on its hyperemic response and compared the images in the same subjects having dipyridamole PET.

Methods

In 32 subjects (23 M), we assessed visually by blinded interpretation and quantitatively compared summed stress and difference scores, total perfusion deficit (TPD), LVEF, LV volumes, and change in stress-rest function. Linear correlation and Bland-Altman analysis of the paired measurements were applied for evaluation of differences. Paired t test and Pearson’s correlation were applied for testing of significance.

Results

The images were interpreted the same by visual assessment. Twenty-six (26) subjects had reversible defects; by quantitation the SSS was 12.9 ± 7.0 and 14.1 ± 6.4 (P = .23) and SDS was 7.0 ± 6.8 versus 7.6 ± 6.2 (P = .40) for dipyridamole and regadenoson, respectively. Six (6) subjects had <5% likelihood of CAD and were normal by both. All paired measurements showed a high positive correlation between regadenoson and dipyridamole; stress segmental perfusion Reg = 0.93Dip + 4.4, r = 0.88; TPD Reg = 0.94Dip + 0.41, r = 0.93; LVEF Reg = 0.92Dip + 4.7, r = 0.95; stress minus rest LVEF Reg = 0.87Dip ? 0.99, r = 0.82.

Conclusion

Regadenoson stress ⁸²RbCl PET perfusion defect and cardiac function measurements are visually and quantitatively equivalent to dipyridamole studies and can be obtained with the clinical advantages of regadenoson.     

Defining predictors for long progression-free survival after radioembolisation of hepatic metastases of neuroendocrine origin

Objectives

To define predictive parameters of long progression-free survival (PFS) in patients undergoing radioembolisation of neuroendocrine liver metastases.

Methods

The following clinical and magnetic resonance imaging (MRI) parameters of 45 radioembolised patients (median age, 62 years; range, 43–75) were reviewed: age, gender, levels of chromogranin A and neuron-specific enolase (NSE), primary tumour site, Ki-67 proliferation index, hepatic tumour load, number of metastases, signal intensity characteristics, vascularisation, haemorrhagic and necrotic transformation and fluid–fluid levels. PFS was assessed according to RECIST 1.0. Statistical analysis included univariate Cox regression, Kaplan–Meier and multivariate regression.

Results

Median PFS was 727 days (95 % CI, 378–964). In the univariate regression analysis, hypovascular metastases progressed earlier (111 vs 727 days; P?<?0.05). A Ki-67 ≤2 % was associated with a longer PFS than a Ki-67 of 3–20 % or >20 % (911 vs 727 vs 210 days, respectively; P?<?0.05). Low NSE predicted longer PFS (911 vs 378 days; P?<?0.05). In the adjusted multivariate analysis, vascularisation (hypervascularisation vs. no hypervascularisation; P?=?0.0009) and NSE level (low vs high; P?=?0.0119) had the strongest influence on PFS.

Conclusion

Response to radioembolisation in patients with neuroendocrine liver metastases can be predicted by the metastatic vascularisation pattern, the NSE level and the Ki-67.

Key Points

? Radioembolisation is an effective treatment in hepatic metastases of neuroendocrine origin. ? Pre-therapeutic vascularisation patterns of metastases on MRI can predict long progression-free survival. ? Assessment of pre-therapeutic markers provides better therapy planning.     

Chronic mitral regurgitation detected on cardiac MDCT: differentiation between functional and valvular aetiologies

Objective

To determine whether cardiac computed tomography (MDCT) can differentiate between functional and valvular aetiologies of chronic mitral regurgitation (MR) compared with echocardiography (TTE).

Methods

Twenty-seven patients with functional or valvular MR diagnosed by TTE and 19 controls prospectively underwent cardiac MDCT. The morphological appearance of the mitral valve (MV) leaflets, MV geometry, MV leaflet angle, left ventricular (LV) sphericity and global/regional wall motion were analysed. The coronary arteries were evaluated for obstructive atherosclerosis.

Results

All control and MR cases were correctly identified by MDCT. Significant differences were detected between valvular and control groups for anterior leaflet length (30?±?7 mm vs. 22?±?4 mm, P?<?0.02) and thickness (3.0?±?1 mm vs. 2.2?±?1 mm, P?<?0.01). High-grade coronary stenosis was detected in all patients with functional MR compared with no controls (P?<?0.001). Significant differences in those with/without MV prolapse were detected in MV tent area (?1.0?±?0.6 mm vs. 1.3?±?0.9 mm, P?<?0.0001) and MV tent height (?0.7?±?0.3 mm vs. 0.8?±?0.8 mm, P?<?0.0001). Posterior leaflet angle was significantly greater for functional MR (37.9?±?19.1° vs. 22.9?±?14°, P?<?0.018) and less for valvular MR (0.6?±?35.5° vs. 22.9?±?14°, P?<?0.017). Sensitivity, specificity, and positive and negative predictive values of MDCT were 100%, 95%, 96% and 100%.

Conclusion

Cardiac MDCT allows the differentiation between functional and valvular causes of MR.     

Stereotactic radiosurgery for newly diagnosed brain metastases

Background and purpose

Three doses were compared for local control of irradiated metastases, freedom from new brain metastases, and survival in patients receiving stereotactic radiosurgery (SRS) alone for one to three newly diagnosed brain metastases.

Patients and methods

In all, 134 patients were assigned to three groups according to the SRS dose given to the margins of the lesions: 13–16 Gy (n?=?33), 18 Gy (n?=?18), and 20 Gy (n?=?83). Additional potential prognostic factors were evaluated: age (≤?60 vs. >?60 years), gender, Karnofsky Performance Scale score (70–80 vs. 90–100), tumor type (non-small-cell lung cancer vs. melanoma vs. others), number of brain metastases (1 vs. 2–3), lesion size (?24 months).

Results

For 13–16 Gy, 18 Gy, and 20 Gy, the 1-year local control rates were 31, 65, and 79?%, respectively (p?p?p?p?=?0.12); 18 Gy showed a strong trend toward better local control when compared with 13–16 Gy (p?=?0.059). Freedom from new brain metastases (p?=?0.57) and survival (p?=?0.15) were not associated with SRS dose in the univariate analysis.

Conclusion

SRS doses of 18 Gy and 20 Gy resulted in better local control than 13–16 Gy. However, 20 Gy and 18 Gy must be compared again in a larger cohort of patients. Freedom from new brain metastases and survival were not associated with SRS dose.     

Impact of initial PET/CT staging in terms of clinical stage,management plan,and prognosis in 592 patients with non-small-cell lung cancer

Purpose

Our objective was to determine the impact of initial ¹⁸F-FDG PET/CT (PET/CT) staging on clinical stage and the management plan and the prognostic value of PET/CT in patients with non-small-cell lung cancer (NSCLC).

Methods

We retrospectively reviewed the records of 592 patients with NSCLC who were referred to The University of Texas MD Anderson Cancer Center during 2002/2011 and had both PET/CT and conventional CT for initial staging. Clinical stages and management plans were compared between PET/CT and CT. The impact of PET/CT on management plans was considered medium/high when PET/CT changed the planned treatment modality or treatment intent. PET/CT and CT stages were compared with all-cause mortality and survival rates. We also assessed potential prognostic factors for progression-free survival (PFS) and overall survival (OS).

Results

PET/CT changed the stage in 170 patients (28.7 %; 16.4 % upstaged, 12.3 % downstaged). PET/CT had a medium/high impact on the management plan in 220 patients (37.2 %). PFS and OS were significantly worse in patients with upstaged disease than in patients with no change in stage (median PFS 29.0 vs. 53.8 months, P?<?0.001; median OS:64.7 vs. 115.9 months, P?=?0.006). PFS and OS were significantly worse in patients with medium/high impact of PET/CT than in patients with no/low impact of PET/CT (median PFS 24.7 vs. 60.6 months, P?<?0.001; median OS 64.7 vs. 115.9 months, P?<?0.001). In multivariate analysis, a medium/high impact of PET/CT was an independent predictor of worse PFS (hazard ratio, HR, 1.73; 95 % CI 1.30 – 2.29; P?=?0.0002) and OS (HR 1.84; 95 % CI 1.26 – 2.69; P?=?0.002).

Conclusion

Initial PET/CT staging not only impacts stage and management plan but also has prognostic value.     

Diagnostic accuracy of low-dose 256-slice multi-detector coronary CT angiography using iterative reconstruction in patients with suspected coronary artery disease

Objectives

To evaluate the accuracy of low-dose coronary CTA with iterative reconstruction (IR) in the diagnosis of coronary artery disease (CAD) in patients with suspected CAD.

Methods

Ninety-six patients with suspected CAD underwent low-dose prospective electrocardiogram-gated coronary CTA, with images reconstructed using IR. Image quality (IQ) of coronary segments were graded on a 4-point scale (4, excellent; 1, non-diagnostic). With invasive coronary angiography (ICA) considered the “gold standard”, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of coronary CTA were calculated on segment-, vessel- and patient-based levels. The patient data were divided into two groups (Agatston scores of ≥ 400 and <400). The differences in diagnostic performance between the two groups were tested.

Results

Diagnostic image quality was found in 98.1 % (1,232/1,256) of segments. The sensitivity, specificity, PPV, NPV and accuracy were 90.8 %, 95.3 %, 81.8 %, 97.8 % and 94.3 % (segment-based) and 97.2 %, 83.3 %, 94.6 %, 90.9 % and 93.8 % (patient-based). Significant differences between the two groups were seen in specificity, PPV and accuracy (92.1 % vs. 97.9 %, 76.0 % vs. 86.7 %, 91.7 % vs. 96.6 %, P?<?0.05; segment-based). The average effective dose was 1.30?±?0.15 mSv.

Conclusion

Low-dose prospective coronary CTA with IR can acquire satisfactory image quality and show high diagnostic accuracy in patients with suspected CAD; however, blooming continues to pose a challenge in severely calcified segments.

Key Points

? Coronary artery disease (CAD) is increasingly investigated using coronary CTA. ? The iterative reconstruction (IR) algorithm is promising in decreasing radiation doses. ? Low-dose prospective coronary CTA with IR can acquire satisfactory image quality. ? Low-dose prospective coronary CTA with IR can show high diagnostic accuracy.     

Anomalous origin of the coronary artery from the wrong coronary sinus evaluated with computed tomography: “High-risk” anatomy and its clinical relevance

Objective

The aim of the study was to assess coronary arteries arising from the wrong coronary sinus, including CT-evaluated high-risk anatomic features, clinical symptoms and cardiac events during follow-up.

Methods

A total of 7,115 patients scheduled for 64-slice or dual-source cardiac CT were screened for the presence of isolated anomalous origin of the coronary artery from the wrong coronary sinus.

Results

Anomalous origin of the coronary artery was found in 54 (0.76 %) patients (29 men, 25 women, mean age 60.9?±?11.6 years). Sixteen (30 %) patients with abnormal right coronary origin (ARCA) more commonly had a slit-like orifice (15 vs. 3; p?p?p?p?=?0.03). Patients with ARCA tended to show higher occurrence of cardiac events in the follow-up than individuals with ALCA and ALCx (5 vs. 4; p?=?NS).

Conclusions

High-risk anatomy features are most common in patients with ARCA and these patients also have higher prevalence of chest pain and cardiac events in the follow-up than individuals with ALCA and ALCx.

Key Points

? Multislice computed tomography enables detection and evaluation of the coronary artery anomalies. ? Anomalous anatomy of the coronary artery potentially influences the prevalence of adverse events. ? Adverse events tend to be most common in anomalous right coronary arteries.     

Dose reduction in dynamic CT stress myocardial perfusion imaging: comparison of 80-kV/370-mAs and 100-kV/300-mAs protocols

Objectives

To determine the effect of reduced 80-kV tube voltage with increased 370-mAs tube current on radiation dose, image quality and estimated myocardial blood flow (MBF) of dynamic CT stress myocardial perfusion imaging (CTP) in patients with a normal body mass index (BMI) compared with a 100-kV and 300-mAs protocol.

Methods

Thirty patients with a normal BMI (<25 kg/m²) with known or suspected coronary artery disease underwent adenosine-stress dual-source dynamic CTP. Patients were randomised to 80-kV/370-mAs (n?=?15) or 100-kV/300-mAs (n?=?15) imaging. Maximal enhancement and noise of the left ventricular (LV) cavity, contrast-to-noise ratio (CNR) and MBF of the two groups were compared.

Results

Imaging with 80-kV/370-mAs instead of 100-kV/300-mAs was associated with 40 % lower radiation dose (mean dose–length product, 359?±?66 vs 628?±?112 mGy?cm; P?<?0.001 ) with no significant difference in CNR (34.5?±?13.4 vs 33.5?±?10.4; P?=?0.81) or MBF in non-ischaemic myocardium (0.95?±?0.20 vs 0.99?±?0.25 ml/min/g; P?=?0.66). Studies obtained using 80-kV/370-mAs were associated with 30.9 % higher maximal enhancement (804?±?204 vs 614?±?115 HU; P?<?0.005), and 31.2 % greater noise (22.7?±?3.5 vs 17.4?±?2.6; P?<?0.001).

Conclusions

Dynamic CTP using 80-kV/370-mA instead of 100-kV/300-mAs allowed 40 % dose reduction without compromising image quality or MBF. Tube voltage of 80-kV should be considered for individuals with a normal BMI.

Key Points

? CT stress perfusion imaging (CTP) is increasingly used to assess myocardial function. ? Dynamic CTP is feasible at 80-kV in patients with normal BMI. ? An 80-kV/370-mAs protocol allows 40 % dose reduction compared with 100-kV/300-mAs. ? Contrast-to-noise ratio and myocardial blood flow of the two protocols were comparable.     

Patency of runoff detected by MR angiography at 3.0 T with cuff-compression: a predictor of successful endovascular recanalization below the knee

Objectives

Our aim was to assess the reliability of detecting distal runoff vessels using contrast-enhanced MR angiography (CE-MRA) that were occult on digital subtraction angiography (DSA) for predicting the outcome of endovascular recanalization (ER).

Methods

This retrospective analysis comprised 63 patients with diabetes (98 limbs) who underwent ER for infrapopliteal lesions. Before ER, they underwent CE-MRA and DSA for peripheral arterial disease; runoff vessels were detected with CE-MRA, but not with DSA. Immediate and follow-up postoperative outcomes were assessed. Univariate analysis was performed to identify variables associated with successful ER.

Results

Successful ER was achieved in 85.7 % of limbs, and runoff score was significantly lower than in failure limbs (5.1?±?1.1 vs. 6.2?±?1.3; P?Restenosis/occlusion rate was higher for patients with CLI at 12 months (48.8 % vs. 96.3 % in claudication; P?P?Conclusion Runoff vessels detected using CE-MRA could indicate immediate success and better outcome of ER for infrapopliteal occlusions.

Key Points

? 3-T MRA with cuff compression displayed distal below-the-knee (BTK) runoffs better than DSA ? Detected runoffs indicate high recanalization rate and good clinical outcome ? Runoff display provides potential opportunity to perform other backup recanalization strategies     

Impact of aortic valve calcification severity and impaired left ventricular function on 3-year results of patients undergoing transcatheter aortic valve replacement

Objectives

To evaluate clinical pre-interventional predictors of 3-year outcome and mortality in high-risk patients with severe aortic valve stenosis treated with transcatheter aortic valve implantation (TAVI).

Methods

Among 367 patients included in the Aachen TAVI registry, 76 patients with baseline dual-source computed tomography (DSCT) for the quantification of aortic valve calcification (AVC) and a 3-year follow-up were identified.

Results

Survival at 30 days was 91 %, and it was 75 %, 66 % and 64 % at 1, 2 years and 3 years, respectively. Non-survivors at 3 years showed a significantly higher Agatston AVC score (2,854?±?1,651) than survivors (1,854?±?961, P?=?0.007). Multivariate analysis including age, logistic EuroScore, glomerular filtration rate, Agatston AVC score, ejection fraction?<?40 %, NYHA class, baseline medication, chronic lung disease and aortic regurgitation revealed that only the Agatston AVC score (P?=?0.03) and impaired left ventricular function (P?=?0.001) was significantly associated with mortality. Patients with Agatston AVC scores >2,000 had a significantly lower 3-year survival rate compared with patients with scores <2,000 (47 % vs 79 %, P?=?0.004).

Conclusions

In patients referred for TAVI, aortic valve calcification severity and impaired left ventricular function may serve as a predictor of long-term mortality. Therefore, AVC scores easily determined from pre-procedural CT datasets may be used for patient risk stratification.

Key Points

? Dual-source CT provides excellent valve delineation before transcatheter aortic valve implantation (TAVI). ? Aortic valve calcification assessed by cardiac CT predicts mortality in TAVI patients. ? Aortic valve calcification scores can help stratify high-risk patients for TAVI. ? Three-year results show good long-term outcome without evidence of structural valve deterioration.     

Characterization and therapy monitoring of head and neck carcinomas using diffusion-imaging-based intravoxel incoherent motion parameters—preliminary results

Introduction

Using the intravoxel incoherent motion (IVIM) model, diffusion-related coefficient (D) and perfusion-related parameter (f) can be measured. Here, we used IVIM imaging to characterize squamous cell carcinomas of head and neck (HNSCC) and evaluated its application in follow-up after nonsurgical organ preserving therapy.

Methods

Twenty-two patients with locally advanced HNSCC (clinical stage III to IVb) were examined before treatment using eight different b values (b?=?0, 50, 100, 150, 200, 250, 700, 800 s/mm²). All patients were followed for at least 7.5 months after conclusion of therapy. In 16 of these patients, follow-up MRI was available. Using the IVIM approach, f and D were extracted using a bi-exponential fit. For comparison, ADC maps were calculated.

Results

The initial values of f before therapy were located between 5.9 % and 12.9 % (mean: 9.4?±?2.4 %) except for two outliers (f?=?17.9 % and 18.2 %). These two patients exclusively displayed poor initial treatment response. Overall, high initial f (13.1?±?4.1 % vs. 9.1?±?2.4 %) and ADC (1.17?±?0.08?×?10^?3?mm²/s vs. 0.98?±?0.19?×?10^?3?mm²/s) were associated with poor short term outcome (n?=?6) after 7.5 months follow-up. D values before treatment were 0.98?×?10^?3?±?0.18 mm²/s and ADC values were 1.03?×?10^?3?±?0.18 mm²/s. At follow-up, in all primary responders, D (69?±?52 %), f (65?±?46 %), and ADC (68?±?49%) increased.

Conclusions

Our preliminary evaluation indicates that an initial high f may predict poor prognosis in HNSCC. In responders, a significant increase of all IVIM parameters after therapy was demonstrated.