Final benefit of primary percutaneous coronary intervention for ST-elevation myocardial infarction in older patients: long-term results of a randomised trial.

BACKGROUND: Although the short-term benefit of primary percutaneous coronary intervention (PCI) in elderly patients with ST-elevation myocardial infarction (STEMI) has been demonstrated, the final long-term survival benefit is as yet unknown. AIM: To assess the final survival benefit of primary PCI as compared to thrombolytic therapy in patients over 75 years of age. METHODS: Patients > 75 years with STEMI were randomised to either primary PCI or thrombolysis. Long-term data on survival were available for all patients. RESULTS: A total of 46 patients were randomised to primary PCI, 41 to thrombolysis. There were no significant differences in baseline variables. After a maximum of 20 years' follow-up, all patients had passed away. The patients randomised to thrombolysis died after a mean follow-up duration of 5.2 years (SD 4.9) compared to 6.7 years (SD 4.8) in patients randomised to primary PCI (p = 0.15). Thus, the mean final survival benefit of primary PCI was 1.5 years. CONCLUSION: The final survival benefit of primary PCI as compared to thrombolysis in elderly patients with STEMI is 1.5 years and their life expectancy increases by 28.8%.

Semi-quantitative assessment of ischemia with rubidium-82 PET myocardial perfusion imaging.

PURPOSE: Semi-quantitative scores can be used as an adjunct to visual assessment in rubidium-82 positron emission tomography (82Rb PET). The semi-quantitative cut-off values used in 82Rb PET are derived from single-photon emission computed tomography (SPECT). It is unknown whether these cut-off values can be extrapolated to 82Rb PET. We compared the semi-quantitative with the visual assessment of ischemia and determined which summed difference score (SDS) score predicts ischemia best. METHODS: We included 108 patients who underwent 82Rb PET imaging and performed visual and semi-quantitative assessment. A scan with a SDS ≥ 2 and a summed stress score (SSS) ≥ 4 was considered to demonstrate ischemia. We compared the semi-quantitative with the visual assessment. RESULTS: 41 (38%) Normal scans, and 67 (62%) scans with ischemia and/or an irreversible defect were included. The semi-quantitative assessment showed ischemia more often than the visual assessment (51% vs 29%, P < .001). Patients with a low or intermediate pre-test probability of coronary artery disease (CAD) and a SDS < 4 did not demonstrate ischemia by visual assessment. CONCLUSION: Semi-quantitative assessment in 82Rb PET imaging clearly demonstrates the presence of ischemia. Ischemia is unlikely in patients with low and intermediate pre-test probability of CAD and a SDS < 4.

Body weight-dependent Rubidium-82 activity results in constant image quality in myocardial perfusion imaging with PET.

BACKGROUND: Clinical practice shows degrading image quality in heavier patients who undergo myocardial perfusion imaging (MPI) with Rubidium-82 (Rb-82) PET when using a fixed tracer activity. Our aim was to derive and validate a patient-specific activity protocol resulting in a constant image quality in PET MPI. METHODS: We included 251 patients who underwent rest MPI with Rb-82 PET (Discovery 670, GE Healthcare). 132 patients were included retrospectively and were scanned using a fixed activity of 740 MBq. The total number of measured prompts was normalized to activity and correlated to body weight, mass per body length and body mass index to find the best predicting parameter. Next, a patient-specific activity was derived and subsequently validated in 119 additional patients. Image quality was scored by three experts on a four-point scale. RESULTS: Both image quality and prompts decreased in heavier patients when using a fixed activity (p < .005). Body weight was used to derive a new activity formula: Activity = 8.3 MBq/kg. When applying this formula, both measured prompts and scored image quality became independent of body weight (p > .60). CONCLUSION: Administrating a Rb-82 activity that linearly depends on body weight resulted in a constant image quality across all patients and is recommended.

Correction to: No need for frame-wise attenuation correction in dynamic Rubidium-82 PET for myocardial blood flow quantification.

Due to the typesetter not carrying out the author's corrections at proof stage, there are two errors in the published article: where "mL × min × g" appears, it should be "mL/min/g". One error is in the Figure 3 caption, and one error is in the second sentence under the heading "MBF Quantification". The original article has been corrected.

Impact of regadenoson-induced myocardial creep on dynamic Rubidium-82 PET myocardial blood flow quantification.

BACKGROUND: Repositioning of the heart during myocardial perfusion imaging (MPI) using Rubidium-82 (Rb-82) PET may occur when using regadenoson. Our aim was to determine the prevalence and the effect of correcting for this myocardial creep on myocardial blood flow (MBF) quantification. METHODS: We retrospectively included 119 consecutive patients who underwent dynamic rest- and regadenoson-induced stress MPI using Rb-82 PET. The presence of myocardial creep was visually assessed in the dynamic stress PET series by identifying differences between the automatically drawn myocardium contour and the activity. Uncorrected and corrected stress MBFs were compared for the three vascular territories (LAD, LCX, and RCA) and for the whole myocardium. RESULTS: Myocardial creep was observed in 52% of the patients during stress. Mean MBF values decreased after correction in the RCA from 4.0 to 2.7 mL/min/g (P  < 0.001), in the whole myocardium from 2.7 to 2.6 mL/min/g (P  = 0.01), and increased in the LAD from 2.5 to 2.6 mL/min/g (P  = 0.03) and remained comparable in the LCX (P  = 0.3). CONCLUSIONS: Myocardial creep is a frequent phenomenon when performing regadenoson-induced stress Rb-82 PET and has a significant impact on MBF values, especially in the RCA territory. As this may hamper diagnostic accuracy, myocardial creep correction seems necessary for reliable quantification.

How to detect and correct myocardial creep in myocardial perfusion imaging using Rubidium-82 PET?

Reliability of myocardial blood flow (MBF) quantification in myocardial perfusion imaging (MPI) using PET can majorly be affected by the occurrence of myocardial creep when using pharmacologically induced stress. In this paper, we provide instructions on how to detect and correct for myocardial creep. For example, in each time frame of the PET images the myocardium contour and the observed activity have to be compared to check for misalignments. In addition, we provide an overview of the functionality of commonly used software packages to perform this quality control step as not all software packages currently provide this functionality. Furthermore, important clinical considerations to obtain accurate MBF measurements are given.

A randomised, investigator-initiated, clinical trial of the effects of fentanyl on P2Y12-receptor inhibition in patients with ST-elevation myocardial infarction who are pre-treated with crushed ticagrelor: rationale and design of the Opioids aNd crushed Ticagrelor In Myocardial infarction Evaluation (ON-TIME 3) trial.

BACKGROUND: Fast and accurate platelet inhibition is an important therapeutic goal in the acute treatment of patients with ST-elevation myocardial infarction (STEMI). Platelet inhibitory effects induced by oral P2Y12-receptor antagonists are delayed in STEMI patients undergoing primary percutaneous coronary intervention (PCI) due to haemodynamic changes and delayed gastro-intestinal absorption. Concomitant use of opioids, although recommended in the American College of Cardiology/American Heart Association and European Society of Cardiology STEMI guidelines, further delays gastro-intestinal absorption. To date, trials investigating alternative analgesics in STEMI patients have been scarce. This trial aims to assess the feasibility of a novel drug strategy for treatment of STEMI patients with crushed ticagrelor in combination with paracetamol (acetaminophen) instead of opioids. HYPOTHESIS: STEMI patients who are pre-treated with crushed ticagrelor and paracetamol have a higher level of platelet inhibition after primary PCI than patients pre-treated with crushed ticagrelor and fentanyl. STUDY DESIGN: The Opioids aNd crushed Ticagrelor In Myocardial infarction Evaluation (ON-TIME 3) trial is a randomised controlled trial designed to examine whether administration of paracetamol instead of fentanyl can optimise platelet inhibition in STEMI patients who are pre-treated with crushed ticagrelor in the ambulance. One hundred and ninety patients with STEMI will be randomised (1:1 fashion) to intravenous (IV) fentanyl or IV paracetamol. The primary endpoint is the level of platelet reactivity units measured immediately after primary PCI. The ON-TIME 3 trial (NCT03400267) aims to achieve optimal platelet inhibition and pain relief in STEMI patients receiving crushed ticagrelor in the ambulance by investigating IV fentanyl and IV paracetamol as analgesics.

No need for frame-wise attenuation correction in dynamic Rubidium-82 PET for myocardial blood flow quantification.

BACKGROUND: Regadenoson-induced stress causes a repositioning of the heart, myocardial creep, in half of the patients undergoing Rubidium-82 (Rb-82) positron emission tomography (PET). As a result, misalignment of dynamic PET and computer tomography (CT) may occur, possibly affecting CT-based attenuation correction (AC) and thereby PET-based myocardial blood flow (MBF) quantification. Our aim was to determine the need for frame-wise PET-CT AC to obtain reliable MBF measurements. METHODS: 31 Out of 64 consecutive patients had myocardial creep during regadenoson-induced stress Rb-82 PET-CT and were included. Prior to PET image reconstruction, we applied two AC methods; single PET-CT alignment and frame-wise alignment in which PET time-frames with myocardial creep were individually co-registered with CT. The PET-CT misalignment was then quantified and MBFs for the three vascular territories and whole myocardium were calculated and compared between both methods. RESULTS: The magnitude of misalignment due to myocardial creep was 13.8 ± 4.5 mm in caudal-cranial direction, 1.8 ± 2.1 mm in medial-lateral and 2.5 ± 1.8 mm in anterior-posterior direction. Frame-wise PET-CT registration did not result in different MBF measurements (P ≥ .07) and the magnitude of misalignment and MBF differences did not correlate (P ≥ .58). CONCLUSION: There is no need for frame-wise AC in dynamic Rb-82 PET for MBF quantification. Single alignment seems sufficient in patients with myocardial creep.

Minimal rest activity for SPECT myocardial perfusion imaging in a one-day stress-first protocol.

PURPOSE: Guidelines propose different rest-stress activity ratios (RSAR) for one-day stress-first SPECT myocardial perfusion imaging (MPI), but evidence is limited. Our aim was to determine and validate the minimal RSAR resulting in the same diagnostic outcome in one-day stress-first SPECT MPI. METHODS: Forty-seven patients referred for rest after stress CZT-SPECT/CT MPI were prospectively included. Rest acquisitions were performed 3 h after stress. In addition to the stress and rest acquisitions, the first 22 patients underwent an additional acquisition prior to the rest injection to determine the remaining stress activity. Next, we simulated six RSARs varying from 1.0 to 3.5 in both patients and a phantom and compared the images to those using the reference RSAR of 4.0. Differences in summed difference score (SDS) >2 or ischemic defect interpretation were considered to significantly influence diagnostic outcome. After deriving the minimal RSAR, it was validated in 25 additional patients by comparing it to a RSAR of 4.0. RESULTS: After 3 h only 26% of the stress activity was still present in the myocardium. SDS differences >2 were found in one (4%) patient using RSAR of 3.5, 2.5 and 2.0, in three (12%) using 1.5 and in five (20%) using SRAR of 1.0. These results were consistent with the phantom study showing SDS differences >2 for RSARs ≤1.5 and with the visual interpretation which showed an increased number of deviating scans for RSAR 1.0. Validating the RSAR of 2.0 resulted in a different SDS in one patient (SDS of 30 versus 11). Moreover, two scans were interpreted as ischemic instead of normal when using RSAR 2.0 and in two other scans the opposite was the case. CONCLUSIONS: A RSAR of 2.0 in one-day stress-first MPI SPECT seems sufficient to obtain accurate diagnostic outcomes and is therefore recommended to reduce radiation exposure.

Use, timing and outcome of coronary angiography in patients with high-risk non-ST-segment elevation acute coronary syndrome in daily clinical practice: insights from a 'real world' prospective registry.

BACKGROUND: An early invasive strategy (EIS) is recommended in high-risk patients with non-ST-elevation acute coronary syndrome (NSTE-ACS), defined as coronary angiography (CAG), within 24 h of admission. The aim of the present study is to investigate guideline adherence, patient characteristics associated with timing of the intervention and clinical outcome. METHODS: In a prospective registry, the use and timing of CAG and the characteristics and clinical outcome associated with timing were evaluated in high-risk ACS patients. The outcome of early versus delayed invasive strategy (DIS) was compared. RESULTS: Between 2006 and 2014, 2,299 high-risk NSTE-ACS patients were included. The use of CAG increased from 77% in 2006 to 90% in 2014 (p trend <0.001) together with a decrease of median time to CAG from 23.3 to 14.5 h (p trend <0.001) and an increase of patients undergoing EIS from 50 to 60% (p trend = 0.002). Patient factors independently related to DIS were higher GRACE risk score, higher age and the presence of comorbidities. No difference was found in incidence of mortality, reinfarction or bleeding at 30-day follow-up. All-cause mortality at 1­year follow-up was 4.1% vs 7.0% in EIS and DIS respectively (hazard ratio 1.67, 95% confidence interval 1.12-2.49) but was comparable after adjustment for confounding factors. CONCLUSION: The percentage of high-risk NSTE-ACS patients undergoing CAG and EIS has increased in the last decade. In contrast to the guidelines, patients with a higher risk profile are less likely to undergo EIS. However, no difference in outcome after 30 days and 1 year was found after multivariate adjustment for this higher risk.

Coronary artery ectasia, an independent predictor of no-reflow after primary PCI for ST-elevation myocardial infarction.

BACKGROUND: The no-reflow phenomenon is a serious complication after primary percutaneous coronary intervention (PCI) for ST-elevation Myocardial Infarction (STEMI). Coronary artery ectasia (CAE) may increase the risk of no-reflow, however, only limited data is available on the potential impact of CAE. The aim of this study was to determine the potential association between CAE and no-reflow after primary PCI. METHODS: A case control study was performed based on a prospective cohort of STEMI patients from January 2000 to December 2011. All patients with TIMI 0-1 flow post primary PCI, in the absence of dissection, thrombus, spasm or high-grade residual stenosis, were considered as no-reflow case. Control subjects were two consecutive STEMI patients after each case, with TIMI flow ≥2 after primary PCI. CAE was defined as dilatation of an arterial segment to a diameter at least 1.5 times that of the adjacent normal coronary artery. RESULTS: In the no-reflow group, frequency of CAE was significantly higher (33.8% vs 3.9%, p < 0.001) compared to the control group. Baseline variables were comparable between patients with and without CAE. Patients with CAE had more often TIMI 0-1 flow pre-PCI (91% vs 71% p = 0.03), less often anterior STEMI (3% vs 37%, p < 0.001) and underwent significantly less often a PCI with stenting (47% vs 74%, p = 0.003). After multivariate analysis, CAE remained a strong and independent predictor of no-reflow (OR 13.9, CI 4.7-41.2, p < 0.001). CONCLUSION: CAE is a strong and independent predictor of no-reflow after primary PCI for STEMI. Future studies should assess optimal treatment.

Predictors of severe stenosis at invasive coronary angiography in patients with normal myocardial perfusion imaging.

PURPOSE: Normal myocardial perfusion imaging (MPI) is associated with excellent prognosis. However, in patients with persisting symptoms, it may be difficult to determine the patients in whom invasive angiography is justified to rule out false negative MPI. We evaluated predictors for severe stenosis at invasive angiography in patients with persisting symptoms after normal MPI. METHODS: 229 consecutive patients with normal MPI, without previous bypass surgery, underwent invasive angiography within 6 months. Older age was defined as >65 years. Multivariable analyses were performed to adjust for differences in baseline variables. RESULTS: Mean age was 62 ± 11 years, 48% were women. Severe stenosis was observed in 34%, and of these patients 60% had single-vessel disease (not left main coronary artery disease). After adjusting for several variables, including diabetes, smoking status, hypertension and hypercholesterolaemia, predictors of severe stenosis were male gender, odds ratio (OR) 2.7 (95% confidence interval (CI) 1.5-4.9), older age, OR 1.9 (95% CI 1.02-3.54) previous PCI, OR 2.0 (95% CI 1.0-4.3) and typical angina, OR 2.5 (95% CI 1.4-4.6). CONCLUSIONS: Increasing age, male gender, previous PCI and typical symptoms are predictors of severe stenosis at invasive coronary angiography in patients with normal MPI. The majority of these patients have single-vessel disease.

Effect of a patient-specific minimum activity in stress myocardial perfusion imaging using CZT-SPECT: Prognostic value, radiation dose, and scan outcome.

BACKGROUND: SPECT Myocardial perfusion imaging (MPI) is associated with a relatively high radiation burden and decreasing image quality in heavy patients. Patient-specific low-activity protocols (PLAPs) are suggested but follow-up data is lacking. Our aim was to compare the use of a standard fixed-activity protocol (FAP) with a PLAP in cadmium zinc telluride (CZT)-SPECT MPI. METHODS: We retrospectively included 1255 consecutive patients who underwent CZT-SPECT stress-optional rest MPI. 668 Patients were scanned using FAP (370 MBq) and 587 patients using PLAP (2.25 MBq·kg-1). Percentage of scans interpreted as normal, radiation dose, and 1-year follow-up including hard event rates (all-cause death or non-fatal myocardial infarction) were collected and compared. RESULTS: The percentage of scans interpreted as normal was 67% in FAP and 70% in PLAP groups (P = .29). The annualized hard event rates in these patients were 1.0% in the FAP and 0.9% in the PLAP group (P = .86). However, the mean radiation dose decreased by 23% for stress-only and by 15% to 2.6 mSv for stress-optional rest MPI after introduction of the PLAP (p<0.001). CONCLUSIONS: Introduction of a patient-specific low-activity protocol does not affect the percentage of scans interpreted as normal or prognosis but significantly lowers the radiation dose for CZT-SPECT MPI.

Everolimus-eluting bioresorbable vascular scaffold in daily clinical practice: A single-centre experience.

BACKGROUND: Recent evidence has raised concerns regarding the safety of the everolimus-eluting bioresorbable vascular scaffold (E-BVS) (Absorb, Abbott Vascular, Santa Clara, CA, USA). Following these data, the use of this device has diminished in the Netherlands; however, daily practice data are limited. Therefore we studied the incidence of safety and efficacy outcomes with this device in daily clinical practice in a single large tertiary centre in the Netherlands. METHODS: All E­BVS treated patients were included in this analysis. The primary endpoint was target lesion failure (TLF), a composite of cardiac death, target vessel non-fatal myocardial infarction (TV-MI) and clinically-driven target lesion revascularisation (TLR). The secondary endpoint was the incidence of definite scaffold thrombosis. RESULTS: Between October 2013 and January 2017, 105 patients were treated with 147 E­BVS. This population contained 42 (40%) patients with diabetes mellitus and 43 (40.9%) undergoing treatment for acute coronary syndrome, and thus represents a high-risk patient cohort. Mean follow-up was 19.8 months. Intravascular imaging guidance during scaffold implantation was used in 64/105 (43.5%) patients. The primary endpoint (TLF) occurred in 3 (2.9%) patients. All-cause mortality and cardiac mortality occurred in 2 (2%) and 0 (0%) patients respectively. TV-MI occurred in 2 patients (1.9%): both were periprocedural and not related to the BVS implantation. TLR occurred in 1 patient (1.0%) during follow-up. No definite scaffold thrombosis occurred during follow-up. CONCLUSION: This single-centre study examining the real-world experience of E­BVS implantation in a high-risk population shows excellent procedural safety and long-term clinical outcomes.

[Hybrid cardiac SPECT-CT proves safe and effective: diagnosis of coronary heart disease completed in one day]. / Hybride cardio-SPECT-CT is veilig en effectief.

Hybrid cardiac SPECT-CT is a technique in which data from both nuclear single photon emission tomography (SPECT) and a CT scan are combined. These techniques are complementary to each other, as CT provides information about anatomy of coronary arteries (stenosis, calcification, aberrant vessels) while SPECT detects functional consequences such as myocardial ischemia. In 2009, the Isala Hospital in Zwolle (the Netherlands) was one of the first centres in Europe to introduce this technique. Hybrid cardiac SPECT-CT has proved to be effective and safe in reaching a comprehensive diagnosis and gives the physician the ability to reach a diagnosis in only one day. In addition, it has led to about 20% fewer invasive coronary angiograms. Utilising this technique requires close collaboration between cardiologists and nuclear medicine specialists.

Value of attenuation correction in stress-only myocardial perfusion imaging using CZT-SPECT.

BACKGROUND: Attenuation correction (AC) improves the diagnostic outcome of stress-only myocardial perfusion imaging (MPI) using conventional SPECT. Our aim was to determine the value of AC using a cadmium zinc telluride-based (CZT)-SPECT camera. METHODS AND RESULTS: We retrospectively included 107 consecutive patients who underwent stress-optional rest MPI CZT-SPECT/CT. Next, we created three types of images for each patient; (1) only displaying reconstructed data without the CT-based AC (NC), (2) only displaying AC, and (3) with both NC and AC (NC + AC). Next, two experienced physicians visually interpreted these 321 randomized images as normal, equivocal, or abnormal. Image outcome was compared with all hard events over a mean follow-up time of 47.7 ± 9.8 months. The percentage of images interpreted as normal increased from 45% using the NC images to 72% using AC and to 67% using NC + AC images (P < .001). Hard event hazard ratios for images interpreted as normal were not different between using NC and AC (1.01, P = .99), or NC and NC + AC images (0.97, P = .97). CONCLUSIONS: AC lowers the need for additional rest imaging in stress-first MPI using CZT-SPECT, while long-term patient outcome remained identical. Use of AC reduces the need for additional rest imaging, decreasing the mean effective dose by up to 1.2 mSv.

Effects of radial versus femoral artery access in patients with acute myocardial infarction: A large centre prospective registry.

AIM: This study sought to assess whether radial artery access improves clinical outcomes in patients presenting with acute myocardial infarction compared with femoral artery access. METHODS: This is a single-centre, prospective observational registry of all STEMI and NSTEMI patients who underwent coronary angiography and/or primary PCI in the period January 2010 to December 2013. Primary endpoint was 30-day all-cause mortality. Choice of access was left to the discretion of the cardiologist. Differences in the risk of death at 30 days between patients undergoing transradial intervention versus transfemoral intervention was assessed on an intention-to-treat comparison. RESULTS: Retrospective analysis of prospectively collected data was performed in 3580 patients with an acute coronary syndrome who underwent coronary angiography, of which 1310 had radial artery access. PCI was performed in 77 % of the patients. Before propensity score matching, patients who underwent transradial intervention and those intended to undergo transfemoral approach differed significantly in intra-aortic balloon pump use (1.7 % vs. 6.7 %, p < 0.001), and Killip class (Killip 1: 10.8 % vs. 17.3 %, p < 0.001). 30-day mortality rates were 1.7 % in the transradial group and 4.6 % in the transfemoral group (p < 0.001). After matching on the propensity score, the hazard ratio for 30-day mortality in the transradial group was 0.56 (95 % CI: 0.29-1.07, p = 0.08). CONCLUSION: This registry-based study showed that radial access is associated with improved outcome in patients with an acute coronary syndrome. However, this difference was no longer significant after multivariate and propensity score adjustment for differences in baseline characteristics.

Diagnosis of takotsubo cardiomyopathy is increasing over time in patients presenting as ST-elevation myocardial infarction.

BACKGROUND: Takotsubo cardiomyopathy often presents with the clinical signs of ST-elevation myocardial infarction (STEMI). The increase in scientific publications addressing this relatively rare condition may result in higher awareness and diagnosis of takotsubo cardiomyopathy. AIM: To assess the observed prevalence per year of takotsubo cardiomyopathy in a large registry of patients with STEMI, during a 12-year inclusion period. METHOD: All patients presenting with STEMI at a large regional cardiology clinic were entered into a database (n = 8,413, mean age 63 ± 13 years). Takotsubo cardiomyopathy was diagnosed in 42 patients (0.5 %). Years of evaluation were defined as 'early years' (January 2002 to December 2007; n = 4350) and 'later years' (January 2008 to December 2013). Multivariable analyses were performed to adjust for differences in demographical and clinical variables. RESULTS: In later years, the age of STEMI patients was slightly higher (64 ± 13 vs. 63 ± 13 years, p < 0.001), with more patients with clinical symptoms of shock (10 vs. 7 %, p < 0.001) or a history of percutaneous coronary intervention or hypertension (10 vs. 8 %, p = 0.001 and 37 vs. 34 %, p < 0.001). Smoking and a positive family history were less often observed during later years (39 vs. 46 %, p < 0.001 and 37 vs. 42 % p < 0.001). Patients with takotsubo cardiomyopathy were more often female (81 vs. 27 %, p = 0.001). Takotsubo cardiomyopathy was more often diagnosed in the later period (0.7 vs. 0.3 %, OR 2.4, 95 % CI 1.2-4.6, p = 0.009). The higher prevalence of takotsubo cardiomyopathy in recent years remained significant after adjustment for differences in patient characteristics (OR 2.1, 95 % CI 1.1-4.3). CONCLUSION: Takotsubo cardiomyopathy is currently more often diagnosed in patients with STEMI compared with in earlier years. This is probably due to the increased scientific and clinical awareness among doctors, but the prevalence is still low.

Visual estimation of coronary calcium on computed tomography for attenuation correction.

BACKGROUND: The coronary calcium score (CCS) provides independent diagnostic and prognostic information on top of myocardial perfusion imaging (MPI) in patients suspected for coronary artery disease, but requires an additional computed tomography (CT) scan. OBJECTIVE: We investigated the accuracy and inter-reader reproducibility of visual estimation of the CCS on the CT used for attenuation correction. METHODS: 250 patients undergoing single photon emission computed tomography MPI and Agatston CCS were included. The CCS was also visually estimated on the CT for attenuation correction by two separate readers blinded to the Agatston CCS, and was categorized into a six-point scale (0, 1-10, 11-100, 101-400, 401-1000 and > 1000). RESULTS: The median Agatston CCS was 82 [25th-75th percentile: 0-562], with a range from 0 to 7287. Of the visually estimated CCS, 60% (reader 1) and 65% (reader 2) were classified correctly into the 6 categories. 93% (reader 1) and 88% (reader 2) of the visually estimated CCS did not vary by more than one category from the Agatston CCS. The intraclass correlation coefficient for agreement between the Agatston CCS and the visually estimated CCS was 0.95 for reader 1 and 0.94 for reader 2. The intraclass correlation coefficient for inter-reader reproducibility of the visually estimated CCS was 0.96. CONCLUSION: The CCS can be accurately estimated on the CT for attenuation correction, as high agreement is demonstrated with the Agatston CCS and inter-reader reproducibility is excellent. If no traditional Agatston CCS is performed, the degree of atherosclerosis should be assessed by means of estimating CCS on the CT for attenuation correction.