Friday, February 28, 2014

Left atrial volume index: relation to long-term clinical outcome in type 2 diabetes.

Left atrial volume index: relation to long-term clinical outcome in type 2 diabetes.
J Am Coll Cardiol. 2013 Dec 24;62(25):2416-21
Authors: Poulsen MK, Dahl JS, Henriksen JE, Hey TM, Høilund-Carlsen PF, Beck-Nielsen H, Møller JE

OBJECTIVES: The study sought to determine the prognostic importance of left atrial (LA) dilation in patients with type 2 diabetes mellitus (T2DM) and no history of cardiovascular disease (CVD).
BACKGROUND: T2DM is associated with the development of CVD, and morphological changes in the heart may appear before symptoms arise.
METHODS: A total of 305 T2DM patients without known CVD referred to a diabetes clinic were included consecutively (age 58.6 ± 11.3 years, diabetes duration 2.0 [interquartile range: 0 to 6.0] years). Each patient underwent a comprehensive echocardiogram and a myocardial perfusion scintigraphy (MPS) at inclusion. Patients were divided according to left atrial volume index (LAVi) ≥32 ml/m(2). Patients were followed for median of 5.6 (interquartile range: 5.1 to 6.1) years for the occurrence of major cardiac events and death.
RESULTS: LAVi ≥32 ml/m(2) was found in 105 patients (34%). During follow-up, 60 patients (20%) experienced the composite endpoint, of whom 28 (9%) died. Patients with LAVi ≥32 ml/m(2) had a significantly higher cardiac event rate and death rate (p < 0.001 and p = 0.002, respectively). Univariate predictors of the composite endpoint were age, hypertension, left ventricular diastolic function, E/e'septum-ratio and LAVi ≥32 ml/m(2); however, myocardial ischemia on MPS was not a predictor. When adjusting for age and hypertension, only LAVi ≥32 ml/m(2) was a predictor of the composite endpoint (hazard ratio: 1.82 [95% confidence interval: 1.08 to 3.07], p = 0.024).
CONCLUSIONS: Increased LAVi was an independent and incremental predictor of cardiovascular morbidity and mortality in T2DM patients with no history of CVD. (Presence of Macrovascular Disease in Type 2 Diabetes Mellitus; NCT00298844).

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Thursday, February 27, 2014

Prognostic Value of PET Myocardial Perfusion Imaging in Obese Patients.


Prognostic Value of PET Myocardial Perfusion Imaging in Obese Patients.
JACC Cardiovasc Imaging. 2014 Feb 12;
Authors: Chow BJ, Dorbala S, Di Carli MF, Merhige ME, Williams BA, Veledar E, Min JK, Pencina MJ, Yam Y, Chen L, Anand SP, Ruddy TD, Berman DS, Shaw LJ, Beanlands RS

OBJECTIVES: This study sought to determine and compare the prognostic and incremental value of positron emission tomography (PET) in normal, overweight, and obese patients.
BACKGROUND: Cardiac rubidium 82 (Rb-82) PET is increasingly being used for myocardial perfusion imaging (MPI). A strength of PET is its accurate attenuation correction, thereby potentially improving its diagnostic accuracy in obese patients. The prognostic value of PET in obese patients has not been well studied.
METHODS: A total of 7,061 patients who had undergone Rb-82 PET MPI were entered into a multicenter observational registry. All patients underwent pharmacologic Rb-82 PET and were followed for cardiac death and all-cause mortality. Based on body mass index (BMI), patients were categorized as normal (<25 kg/m(2)), overweight (25 to 29.9 kg/m(2)), or obese (≥30 kg/m(2)). Using a 17-segment model and 5-point scoring system, the percentage of abnormal myocardium was calculated for stress and rest patients categorized as normal (0%), mild (0.1% to 9.9%), moderate (10% to 19.9%), and severe (≥20%).
RESULTS: A total of 6,037 patients were followed for cardiac death (median: 2.2 years) and the mean BMI was 30.5 ± 7.4 kg/m(2). A total of 169 cardiac deaths were observed. PET MPI demonstrated independent and incremental prognostic value over BMI. Normal PET MPI conferred an excellent prognosis with very low annual cardiac death rates in normal (0.38%), overweight (0.43%), and obese (0.15%) patients. As well, both moderately and severe obese patients with a normal PET MPI had excellent prognosis (0.20% and 0.10%, respectively). The net reclassification improvement of PET was 0.46 (95% confidence interval [CI]: 0.31 to 0.61), and appeared similar in the moderately and severe obese patients which were 0.44 (95% CI: 0.12 to 0.76) and 0.63 (95% CI: 0.27 to 0.98), respectively.
CONCLUSIONS: Rb-82 PET has incremental prognostic value in all patients irrespective of BMI. In the obese population, where other modalities may have reduced diagnostic accuracy, cardiac PET appears to be a promising noninvasive modality with prognostic value.

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Can left ventricular parameters examined by gated myocardial perfusion scintigraphy and strain echocardiography be prognostic factors for major adverse cardiac events?


Can left ventricular parameters examined by gated myocardial perfusion scintigraphy and strain echocardiography be prognostic factors for major adverse cardiac events?
Hell J Nucl Med. 2014 Feb 21;
Authors: Karacavus S, Celik A, Tutus A, Kula M, Oguzhan A, Kalay N

Assessment of left ventricular (LV) function in patients with myocardial infarction (MI) provide useful diagnostic and prognostic information. Up to date, single photon emission tomography (SPET), positron emission tomography (PET), multidetector computed tomographic angiography, echocardiography (EC) and magnetic resonance imaging (MRI), have been used to examine LV parameters. However, due to limitations of some imaging methods, new studies are directed to improve myocardium function evaluation. In conclusion, SEC and GSPET can be applied to semi-quantitatively assess LVEF and regional wall motion abnormalities in a noninvasive manner. These techniques can provide strong diagnostic and prognostic information related to anterior myocardial infarction. In addition to this, nitrate enhanced GSPET allows to identify stunning and hibernating myocardium. New methods of reconstruction on GSPET systems will better improve image quality using lower count rates.

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Monday, February 24, 2014

Coronary sinus filling time: a novel method to assess microcirculatory function in patients with angina and normal coronaries.

Coronary sinus filling time: a novel method to assess microcirculatory function in patients with angina and normal coronaries.
Indian Heart J. 2013 Mar-Apr;65(2):142-6
Authors: Haridasan V, Nandan D, Raju D, Rajesh GN, Sajeev CG, Vinayakumar D, Muneer K, Babu K, Krishnan MN

OBJECTIVE: Dysfunction of the coronary microcirculation is considered as one of the factors responsible for symptoms and abnormal stress tests in patients with angina and normal coronaries (syndrome X). We sought to evaluate the usefulness of coronary sinus filling time (CSFT) to assess coronary microcirculation in this group of patients.
METHODS: We compared the CSFT of patients having definite angina or atypical angina with positive treadmill electrocardiography test (angina group), with that of patients undergoing coronary angiogram (CAG) prior to balloon mitral valvuloplasty (control group). During CAG, coronary sinus was visualized in appropriate views and CSFT in seconds was derived from frame count. Thrombolysis In Myocardial Infarction (TIMI) flow grade, corrected TIMI (cTIMI) frame count, TIMI Myocardial Perfusion grade (TMP) were assessed.
RESULTS: There were 41 patients in angina group and 16 in control group. Among the angina group 68.8% were females as against 81.8% in the control group. 87.8% (n = 36) had typical angina. Mean CSFT was 4.25 ± 0.72 s and 3.46 ± 0.99 s in the angina group and control group respectively (p = 0.001). No significant differences were found between the groups with respect to TMP (p = 0.68) & cTIMI frame count (p = 0.22).
CONCLUSION: CSFT is a simple method to assess the transit time through coronary microcirculation. CSFT was significantly delayed in patients with angina and normal coronaries. TMP and cTIMI frame count were not significantly different between groups.

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Saturday, February 22, 2014

Initial human experience with Rubidium-82 renal PET/CT imaging.


Initial human experience with Rubidium-82 renal PET/CT imaging.
J Med Imaging Radiat Oncol. 2014 Feb;58(1):25-31
Authors: Tahari AK, Bravo PE, Rahmim A, Bengel FM, Szabo Z

INTRODUCTION: Preclinical data have shown that Rubidium-82 chloride ((82) Rb) is a radiotracer with high first pass extraction and slow washout in the kidneys. The goal of this study was to investigate the feasibility of human kidney imaging with (82) Rb positron emission tomography (PET) and obtain quantitative data of its uptake non-invasively.
METHODS: Eight healthy volunteers underwent dynamic PET/CT imaging with (82) Rb. A preprogrammed pump was used to insure reproducible injections. Tissue time activity curves were generated from the renal cortex. An input function was derived from the left ventricular blood pool (LVBP), the descending thoracic aorta and the abdominal aorta. Renal blood flow was estimated by applying a two-compartment kinetic model. Results obtained with different input functions were compared.
RESULTS: Radiotracer accumulation was rapid and reached a plateau within 15-30 s after the bolus entered the kidneys. The derived K1 and k2 parameters were reproducible using input functions obtained from diverse vascular locations. K1 averaged 1.98 ± 0.14 mL/min/g. The average k2 was 0.35 ± 0.11/min. Correlation between K1 values obtained from the LVBP from different bed positions when the kidneys and abdominal aorta were in the same field of view was excellent (R = 0.95).
CONCLUSIONS: Non-invasive quantitative human kidney imaging with (82) Rb PET is feasible. Advantages of renal PET with (82) Rb include excellent image quality with high image resolution and contrast. (82) Rb has potential as a clinical renal imaging agent in humans.

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Patient- and clinician-reported satisfaction with pharmacological stress agents for single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI).

Patient- and clinician-reported satisfaction with pharmacological stress agents for single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI).
J Med Econ. 2013;16(6):828-34
Authors: Hudgens S, Breeze J, Spalding J

OBJECTIVE: The objective of this study was to compare clinician and patient measures of satisfaction with two pharmacological stress agents (PSA), regadenoson and dipyridamole, used in Single Photon Emission Computed Tomography (SPECT) Myocardial Perfusion Imaging (MPI).
METHODS: This observational study included patients who had undergone SPECT MPI with regadenoson or dipyridamole, as well as the clinician/clinical technologist who performed the test. Mean scores for individual item and domain scores of the main outcome measures were computed as well as the effect sizes (ES) of the mean difference in scores between treatment groups. Statistical significance of the mean item and domain score differences were assessed via Mann-Whitney tests. Main outcome measures: Two self-report questionnaires which had beeb previously developed and validated: Patient Satisfaction/Preference Questionnaire (PSPQ) and Clinician Satisfaction/Preference Questionnaire (CSPQ).
RESULTS: A total of 87 patients (68 received regadenoson, 19 received dipyridamole) and nine clinicians/clinical technologists took part in the study. Patients had a mean age of 66.8 ± 12.2 years, and 56.3% were male. Compared to dipyridamole, use of regadenoson was associated with greater clinician satisfaction on all items and domains of the CSPQ (p < 0.001 for all comparisons). Among patients, regadenoson was associated with less bother and greater satisfaction than dipyridamole for all items on the PSPQ. These patients reported less stinging at the injection site (ES = -0.66) and less nervousness during injection (ES = -0.60). The PSPQ found that regadenoson patients were more satisfied with their PSA than dipyridamole patients in all areas.
LIMITATIONS: This study utilized a relatively small sample size of dipyridamole patients and lacked an adenosine group. A broader sampling of professionals would also help demonstrate generalizability.
CONCLUSION: Both patients and clinicians reported higher satisfaction with regadenoson compared to dipyridamole for SPECT-MPI. Clinicians were particularly satisfied with the preparation and administration aspects of the drug, while patients rated it highly on convenience and reduced incidence of side-effects.

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Successful transcatheter closure of coronary artery fistula in a child with single coronary artery: a heavy load and a long road.

Successful transcatheter closure of coronary artery fistula in a child with single coronary artery: a heavy load and a long road.
Catheter Cardiovasc Interv. 2013 Jul 1;82(1):150-4
Authors: Phasalkar M, Thakkar B, Poptani V

Single coronary artery is an uncommon variation of the coronary circulation. After transposition of great arteries, coronary artery fistulas are the most common associated cardiac anomalies in these patients. Transcatheter closure of coronary artery fistula (CAF) involving single coronary artery is a challenging intervention. In the absence of contralateral coronary artery, a complex anatomy of the CAF and a large myocardial perfusion territory of the dominant circulation pose an additional risk during interventional procedure. We report our experience of a successful transcatheter closure of a coronary artery fistula in a patient with single coronary artery.

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'Warm-up Angina': harnessing the benefits of exercise and myocardial ischaemia.

'Warm-up Angina': harnessing the benefits of exercise and myocardial ischaemia.
Heart. 2014 Jan;100(2):106-14
Authors: Williams RP, Manou-Stathopoulou V, Redwood SR, Marber MS

The phenomenon of warm-up angina was first noted over 200 years ago. It describes the curious observation whereby exercise-induced ischaemia on second effort is significantly reduced or even abolished if separated from first effort by a brief rest period. However, the precise mechanism via which this cardio-protection occurs remains uncertain. Three possible explanations for reduced myocardial ischaemia on second effort include: first, an improvement in myocardial perfusion; second, increased myocardial resistance to ischaemia similar to ischaemic preconditioning; and third, reduced cardiac work through better ventricular-vascular coupling. Obtaining accurate coronary physiological measurements in the catheter laboratory throughout exercise demands a complex research protocol. In the 1980s, studies into warm-up angina relied on great cardiac vein thermo-dilution to estimate coronary blood flow. This technique has subsequently been shown to be inaccurate. However exercise physiology in the catheter laboratory has recently been resurrected with the advent of coronary artery wires that allow continuous measurement of distal coronary artery pressure and blood flow velocity. This review summarizes the intriguing historical background to warm-up angina, and provides a concise critique of the important studies investigating mechanisms behind this captivating cardio-protective phenomenon.

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Wednesday, February 19, 2014

Validation of an automated method to quantify stress-induced ischemia and infarction in rest-stress myocardial perfusion SPECT.


Validation of an automated method to quantify stress-induced ischemia and infarction in rest-stress myocardial perfusion SPECT.
J Nucl Cardiol. 2014 Feb 15;
Authors: Fransson H, Ljungberg M, Carlsson M, Engblom H, Arheden H, Heiberg E

BACKGROUND: Myocardial perfusion SPECT (MPS) is one of the frequently used methods for quantification of perfusion defects in patients with known or suspected coronary artery disease. This article describes open access software for automated quantification in MPS of stress-induced ischemia and infarction and provides phantom and in vivo validation.
METHODS AND RESULTS: A total of 492 patients with known or suspected coronary artery disease underwent both stress and rest MPS. The proposed perfusion analysis algorithm (Segment) was trained in 140 patients and validated in the remaining 352 patients using visual scoring in MPS by an expert reader as reference standard. Furthermore, validation was performed with simulated perfusion defects in an anthropomorphic computer model. Total perfusion deficit (TPD, range 0-100), including both extent and severity of the perfusion defect, was used as the global measurement of the perfusion defects. Mean bias ± SD between TPD by Segment and the simulated TPD was 3.6 ± 3.8 (R (2) = 0.92). Mean bias ± SD between TPD by Segment and the visual scoring in the patients was 1.2 ± 2.9 (R (2 )= 0.64) for stress-induced ischemia and -0.3 ± 3.1 (R (2) = 0.86) for infarction.
CONCLUSION: The proposed algorithm can detect and quantify perfusion defects in MPS with good agreement to expert readers and to simulated values in a computer phantom.

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CT-based attenuation correction in Tl-201 myocardial perfusion scintigraphy is less effective than non-corrected SPECT for risk stratification.


CT-based attenuation correction in Tl-201 myocardial perfusion scintigraphy is less effective than non-corrected SPECT for risk stratification.
J Nucl Cardiol. 2014 Feb 15;
Authors: Savvopoulos CA, Spyridonidis T, Papandrianos N, Vassilakos PJ, Alexopoulos D, Apostolopoulos DJ

BACKGROUND: Previous studies advocate the use of attenuation correction in myocardial perfusion scintigraphy (MPS) for patient risk stratification.
METHODS: Six-hundred and thirty-seven unselected patients underwent Tl-201 MPS by a hybrid SPECT/CT system. Attenuation-corrected (AC) and non-corrected (NAC) images were interpreted blindly and summed stress scores (SSS) were calculated. Study endpoints were all-cause mortality and the composites of death/non-fatal acute myocardial infarction (AMI) and death/AMI/late revascularization.
RESULTS: During a follow-up of 42.3 ± 12.8 months 24 deaths, 13 AMIs and 28 revascularizations were recorded. SSS groups formed according to event rate distribution across SSS values were: 0-4, 5-13, >13 for NAC and 0-2, 3-9, >9 for AC. Kaplan-Meier functions were statistically significant between NAC SSS groups for all study endpoints. AC discriminated only between SSS 0-2 and >9 for death/AMI and between 0-2 and 3-9 for death/AMI/revascularization. In the univariate Cox regression abnormal NAC (SSS > 4) was accompanied with much higher hazards ratios than abnormal AC (SSS > 2). In the multivariate model abnormal AC yielded no significance for either endpoint whereas abnormal NAC proved independent from other covariates for the composite endpoints.
CONCLUSION: Our results challenge the effectiveness of CT-based AC for risk stratification of patients referred for MPS.

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The effects of dobutamine stress on cardiac mechanical synchrony determined by phase analysis of gated SPECT myocardial perfusion imaging in a canine model.

The effects of dobutamine stress on cardiac mechanical synchrony determined by phase analysis of gated SPECT myocardial perfusion imaging in a canine model.
J Nucl Cardiol. 2014 Jan 9;
Authors: Salimian S, Thibault B, Finnerty V, Grégoire J, Harel F

BACKGROUND: Precise identification of left ventricular (LV) systolic mechanical dyssynchrony may be useful in optimizing the response to cardiac resynchronization therapy in heart failure (HF) patients. However, LV dyssynchrony is mostly measured at rest; patients often suffer from the HF symptoms during exercise.
OBJECTIVES: Our objective was to examine the impacts of stress on LV synchronism with phase analysis of gated SPECT myocardial perfusion imaging (GMPS) within a normal animal cohort.
METHODS: Stress was induced with different levels of dobutamine infusion in six healthy canine subjects. Hemodynamic properties were assessed by LV pressure measurements. Also, LV mechanical synchronism (coordination of LV septal and lateral wall at the time of contraction) was determined by phase analysis of GMPS using commercially available QGS software and in-house MHI4MPI software, with the thickening- and displacement-based method. Synchrony indexes in MHI4MPI included the septal-to-lateral delay and homogeneity index, derived from each of the two methods. Also, bandwidth, SD, and entropy (synchrony indexes) of the QGS software were assessed.
RESULTS: LVEF increased from 36.7% ± 8.7% at rest to 53.67% ± 12.34% at 20 μg·kg(-1)·minute(-1) (P < .001). Also, cardiac output increased from 3.67 ± 1.0 L·minute(-1) at rest to 8.4 ± 2.6 L·minute(-1) at 10 μg·kg(-1)·minute(-1) (P < .001). The same trend was observed for dP/dt max which increased from 1,247 ± 382.7 at rest to 5,062 ± 1,800 mm Hg·s(-1) at 10 μg·kg(-1)·minute(-1) (P < .01). Entropy decreased from 55.2% ± 8% at baseline to 43.5% ± 8.5% at 5 and 43.0% ± 3.7% at 10 μg·kg(-1)·minute(-1) dobutamine (P < .01). Thickening homogeneity index showed a difference from 91.7% ± 5.53% at rest to 98.2% ± 0.75% at 20 μg·kg(-1)·minute(-1) (P < .05).
CONCLUSIONS: Dobutamine stimulation could amplify the ventricular synchronism, and the thickening-based approach is more accurate than wall displacement for assessment of mechanical dyssynchrony in GMPS.

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Tuesday, February 18, 2014

Use of myocardial perfusion imaging and estimation of associated radiation doses in Germany from 2005 to 2012.

Use of myocardial perfusion imaging and estimation of associated radiation doses in Germany from 2005 to 2012.
Eur J Nucl Med Mol Imaging. 2014 Feb 12;
Authors: Lindner O, Bengel FM, Hacker M, Schäfer W, Burchert W, Working Group Cardiovascular Nuclear Medicine of the German Society of Nuclear Medicine

PURPOSE: For several years the Working Group Cardiovascular Nuclear Medicine of the German Society of Nuclear Medicine has been performing a regular survey to obtain information on technique, utilization and development of myocardial perfusion scintigraphy (MPS). Currently, data of six surveys from 2005 to 2012 are available. The aim of this paper is to deliver a general and comprehensive overview of all surveys documenting the course of patient doses over time and the development of the method.
METHODS: A one-page questionnaire with number of MPS patients, number of stress and rest MPS, referral structure and several technical issues was sent to all centres performing MPS in Germany and evaluated. With the data on protocol utilization, effective MPS patient doses were estimated.
RESULTS: MPS per million population (pmp) varied between 2,380 and 2,770. In 2012, MPS pmp showed a slight increase for the first time. From 2005 to 2009 the angiography to MPS ratio increased from 3.4 to 4.4, and the revascularization to MPS ratio decreased from 0.66 to 0.53. In 2012, both indices demonstrated an opposite trend for the first time (4.1 and 0.55). A total of 108 centres participated in all surveys. They showed an increase in MPS patients of 4.0 % over the reporting period. In 2012, more than 50 % of the centres experienced no change or an increase in MPS numbers. The leading single competitor was MRI, followed by angiography and stress echocardiography. (201)Tl studies have decreased since 2005 from 20 to 5 %. (99m)Tc MPS studies showed a mild increase in 2-day protocols. In 2012, the average effective dose per patient was estimated at 7.4 mSv. Due to the decreasing use of (201)Tl, a mild decline over the observation period can be documented. Dynamic exercise stress was the most common stress test and adenosine the leading pharmacological stress agent, with a growing percentage. In 2012, the regadenoson percentage was 9 %. Gated single photon emission computed tomography (SPECT) noted an increasing acceptance with >70 % in 2012. The segmental scoring of perfusion studies had a low acceptance. Ambulatory care cardiologists represented the major referral group.
CONCLUSION: Germany has a moderate to moderate-high MPS utilization rate. Nevertheless, coronary artery disease (CAD) diagnosis and disease management are dominated by angiography. The survey data reveal a positive trend in MPS and a decrease in average patient dose reflecting good practice with guideline adherence, the implementation of technical improvements and success in training.

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Sunday, February 16, 2014

Angiographic outcomes in the PLATO Trial (Platelet Inhibition and Patient Outcomes).

Angiographic outcomes in the PLATO Trial (Platelet Inhibition and Patient Outcomes).
JACC Cardiovasc Interv. 2013 Jul;6(7):671-83
Authors: Kunadian V, James SK, Wojdyla DM, Zorkun C, Wu J, Storey RF, Steg PG, Katus H, Emanuelsson H, Horrow J, Maya J, Wallentin L, Harrington RA, Gibson CM

OBJECTIVES: The PLATO (Platelet Inhibition and Patient Outcomes) angiographic substudy sought to compare the efficacy of ticagrelor versus clopidogrel with respect to angiographic outcomes before and after PCI in the setting of acute coronary syndrome.
BACKGROUND: Greater platelet inhibition has been associated with improved angiographic outcomes before and after percutaneous coronary intervention (PCI). Therefore, it was hypothesized that treatment with ticagrelor, which achieves more rapid, higher, and more consistent platelet inhibition, would be associated with improved angiographic outcomes when compared with those of clopidogrel treatment.
METHODS: The angiographic cohort consists of 2,616 patients drawn from the 18,624-patient PLATO trial. Clopidogrel naïve or pre-treated patients were randomized to 180 mg of ticagrelor or 300 mg of clopidogrel (75 mg for clopidogrel pre-treated patients). PCI patients were administered, as per treatment group: 1) an additional 90 mg of ticagrelor if >24 h following the initial loading dose; or 2) an optional further 300 mg of clopidogrel or placebo (total 600 mg) prior to PCI. The substudy primary endpoint was the incidence of post-PCI TIMI (Thrombolysis In Myocardial Infarction) myocardial perfusion grade 3 (TMPG 3) among patients who received a study drug prior to PCI.
RESULTS: In total, 21.3% of patients were pretreated with clopidogrel prior to randomization. There was a short time interval between randomization and PCI (median: 0.68 [interquartile range (IQR): 0.30 to 2.21] h) among all patients. Post-PCI TMPG 3 was similar between the ticagrelor and clopidogrel groups (47.1% vs. 46.9%; p = 0.96). Likewise, the following pre-PCI outcomes were similar in the ticagrelor and clopidogrel groups, respectively: TMPG 3 (30.5% vs. 31.2%), TIMI flow grade 3 (37.1% vs. 39.3%), corrected TIMI frame count (median: 100 vs. 71 frames), TIMI thrombus grade 0 (24.1% vs. 27.6%), minimum lumen diameter (median: 0.3 [IQR: 0.0 to 0.6] vs. 0.3 [IQR: 0.0 to 0.6] mm) and percentage of diameter stenosis (median: 89 [IQR: 78 to 100] vs. 89 [IQR: 77 to 100]).
CONCLUSIONS: Neither coronary flow nor myocardial perfusion, evaluated on coronary angiograms performed before or following PCI procedures within a few hours after the start of oral antiplatelet treatment in the setting of acute coronary syndromes, demonstrated a difference with ticagrelor versus clopidogrel. (A Comparison of Ticagrelor [AZD6140] and Clopidogrel in Patients With Acute Coronary Syndrome [PLATO]; NCT00391872).

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Friday, February 14, 2014

Is the diagnostic yield of myocardial stress perfusion MRI impaired by three-vessel coronary artery disease?

Is the diagnostic yield of myocardial stress perfusion MRI impaired by three-vessel coronary artery disease?

Acta Radiol. 2014 Feb 12;

Authors: Klumpp B, Miller S, Seeger A, May A, Gawaz M, Claussen C, Kramer U


BACKGROUND: Three-vessel coronary artery disease (CAD) comes along with globally reduced myocardial perfusion potentially restricting the demarcation of regional hypoperfusion in stress perfusion cardiac magnetic resonance imaging (MRI).
PURPOSE: To evaluate whether stress perfusion cardiac MRI is capable of detecting myocardial hypoperfusion in patients with 3-vessel CAD reliably.
MATERIAL AND METHODS: Two hundred and five patients with symptoms of CAD were included. The examination protocol comprised imaging of myocardial perfusion at stress (0.14 mg/kg/min adenosine for 4 min) using a 2D saturation recovery gradient echo sequence after administration of gadobutrol (0.1 mmol/kg body weight). Perfusion sequences were assessed qualitatively by two experienced observers. Coronary angiography served as standard of reference.
RESULTS: Sensitivity and specificity for hemodynamically relevant stenoses in patients with 0-, 1-, 2-, 3-vessel coronary artery disease were 100%/91%, 91%/73%, 90%/71%, 92%/64%; positive/negative predictive value, 67%/100%, 91%/73%, 83%/81%, 93%/58%; diagnostic accuracy, 93%/87%/83%/87%, respectively. The negative predictive value in patients with 3-vessel CAD was lower than in patients with 0- and 2-vessel CAD and the specificity lower than in patients with no CAD whereas the positive predictive value was higher than in patients with no CAD. The other proportions did not differ significantly between the groups.
CONCLUSION: The diagnostic value of stress perfusion cardiac MRI in patients with 3-vessel CAD is comparable to results in patients with 1- or 2-vessel CAD. In the rare event that stress perfusion images do not depict regional hypoperfusion in patients with severe 3-vessel CAD, myocardial ischemia could be identified by reduced semi-quantitative perfusion parameters.

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