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La radiologia medicaOfficial Journal of the Italian Society ofMedical Radiology ISSN 0033-8362 Radiol medDOI 10.1007/s11547-015-0518-0

Italian Registry of Cardiac ComputedTomography

CCT Italian Registry Group

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Radiol medDOI 10.1007/s11547-015-0518-0

CARDIAC RADIOLOGY

Italian Registry of Cardiac Computed Tomography

Filippo Cademartiri · Ernesto Di Cesare · Marco Francone · Giovanni Ballerini · Guido Ligabue · Erica Maffei · Andrea Romagnoli · Giovanni Maria Argiolas · Vincenzo Russo · Vitaliano Buffa · Riccardo Marano · Maria Guzzetta · Manuel Belgrano · Iacopo Carbone · Luca Macarini · Claudia Borghi · Paolo Di Renzi · Vicenzo Barile · Lucia Patriarca · CCT Italian Registry Group

Received: 10 October 2014 / Accepted: 28 January 2015 © Italian Society of Medical Radiology 2015

3,185 patients (92.5 %). Mean DLP changes with type of scanner and was lower in >64 row detector scanner. The most frequent indication for CCT was suspected CAD (44.8 %), followed by calcium scoring (9.6 %), post-angi-oplasty/stenting (8.3 %), post-CABGs (7.5 %), study of cardiac anatomy (4.22 %) and assessment in patients with known CAD (4.1 %) and acute chest pain (1.99 %). Most of the CCTs were performed in outpatient settings (2,549; 74 %) and a minority in inpatient settings (719, 20.8 %). Adverse clinical events (mild–moderate) occurred in 26 examinations (0.75 %). None of them was severe. In 45.3 % of the cases CCT findings impacted patient management.

Abstract Purpose Cardiac CT (CCT) is an imaging modality that is becoming a standard in clinical cardiology. We evaluated indications, safety, and impact on patient management of routine CCT in a multicenter national registry.Materials and methods During a period of 6 months, 47 centers in Italy enrolled 3,455 patients.Results CCT was performed mainly with 64-slice CT scanners (73.02 %). Contrast agents were administrated in

F. Cademartiri and E. Di Cesare contributed equally to this work.

The list of members of the CCT Italian Registry Group is given in "Appendix”.

F. Cademartiri · E. Maffei Cardio-Vascular Imaging Unit, Giovanni XXIII Hospital, Monastier di Treviso, Italy

F. Cademartiri · E. Maffei Erasmus Medical Center University, Rotterdam, The Netherlands

E. Di Cesare (*) · L. Patriarca Dipartimento di Scienze Cliniche Applicate e Biotecnologie, Università di L’Aquila, Via Vetoio 1, 67100 L’Aquila, Italye-mail: ernesto.dicesare@cc.univaq.it

M. Francone · I. Carbone Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome, Rome, Italy

G. Ballerini IRCCS Centro Cardiologico Monzino, Milan, Italy

G. Ligabue Azienda Ospedaliera-Universitaria Policlinico di Modena, Modena, Italy

A. Romagnoli Policlinico Universitario Tor Vergata, Rome, Italy

G. M. Argiolas Azienda ospedaliera G Brotzu, Cagliari, Italy

V. Russo Policlinico S. Orsola, Bologna, Italy

V. Buffa Ospedale San Camillo Folanini, Rome, Italy

R. Marano Policlinico Gemelli, Università Cattolica, Rome, Italy

M. Guzzetta Azienda Ospedale-Università, Padua, Italy

M. Belgrano UOC di Radiologia OspCattinara, Trieste, Italy

L. Macarini Department of Diagnostic Imaging, University of Foggia, Foggia, Italy

C. Borghi Radiologia Ospedale,Valduce, Como, Italy

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Conclusion CCT is performed with different workloads in participating centers. It is a safe procedure and its results have a strong impact on patient management.

Keywords Heart diseases · Coronary artery · Cardiac CT · Indications · Registry

Introduction

Cardiac computed tomography (CCT) is now an estab-lished diagnostic tool for cardiac diseases and coronary artery disease (CAD). This is the result of several years of ongoing technical development and protocol optimiza-tion combined with improved international guidelines and appropriateness criteria that cover a wide spectrum of clini-cal indications [1–7].

The number of hospitals and imaging centers that per-form CCT investigations has been constantly growing as is the number of patients that undergo the test. However, most clinical information about the use and diagnostic per-formance of CCT derives from relatively few large-scale clinical trials or from selected populations enrolled in highly specialized centers. Thus, there is relatively limited knowledge of its day-to-day utilization. There are currently position statements, recommendations and guidelines on the clinical use of CCT and some documents on appropri-ateness upon which the various centers base their activities [8–11].

The Italian Registry of CCT is an open-access forum (no restriction criteria or proof of specific competence is required from participating centers) which was set up to provide a national overview of cardiac CT utilization that offers a more “radiological” view of the current clinical role of CCT in daily practice. The Italian Registry was pro-moted by the Sub-society of Cardiac Radiology of the Soci-età Italiana di Radiologia Medica (SIRM), which currently includes almost 700 members (www.sirm.org/sottositi/cardio).

Knowledge of the geographic distribution of CCT pro-grams, as well as the use and spectrum of technological equipment and different diseases assessed in each partici-pating center, might be of great importance not only for epidemiological analyses, but also to create a large com-mon national database of patients for further pathology-focused studies. These, in turn, might provide a trigger for further multicenter trials and large scientific cooperation.

Forty-seven sites were involved in this multicenter and multivendor registry. The aims were to evaluate the clini-cal indications, the spectrum of acquisition protocols, the impact on clinical decision-making and the safety profile of cardiac CT.

Materials and methods

Data collection

The data were prospectively collected during a 6-month period (January–June 2011). During this period 3,455 con-secutive patients underwent cardiac CT in one of the 47 participating centers.

Centers were initially recruited via email from the mail-ing list of the SIRM members (approximately 9,000 mem-bers) and each site, after acceptance, appointed a referral physician (a radiologist) who was locally responsible for data integrity, interpretation and collection and represented the direct contact for the steering committee of study.

Referral physicians were not required to exhibit any spe-cific sub-society-based certificate of competency in CCT imaging as the aim of the present registry was to provide a real-world “snapshot” of CCT utilization in Italy, without limiting patient enrollment only to the most experienced national groups.

Similarly, acquisition protocols were individually defined and tailored by each center according to the main clinical request, without following any established, prede-fined or standardized protocol.

Data collection

Preliminary general reports and case report forms (CRF) were completed at each center.

In each electronic form, the following sections had to be filled in:

1. Patient data, including name, age, weight and height, patient source (outpatient, day hospital or hospitalized) and clinical priority (defined as urgent vs. elective examination).

2. Clinical indications for the examination, which were listed and readapted following the ACCF/ACR/SCCT/SCMR/ASNC/NASCI/SCAI/SIR appropriateness criteria for cardiac computed tomography and car-diac magnetic resonance imaging published in 2010 (calcium scoring, suspected coronary artery disease (CAD), follow-up in patients with known coronary dis-ease, follow-up in patients after coronary artery bypass grafting, acute chest pain, study of cardiac anatomy, other).

P. Di Renzi Fate Bene Fratelli Isola tiberina, Rome, Italy

V. Barile Ospedale di Villa D’Agri, Masciovetere, Italy

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3. Acquisition data regarding brand and model of the scanner utilized, number of detector rows, type, dose and flow rate of contrast agents used. Patient compli-ance was also evaluated on a five-point scale from inadequate (0) to excellent (5).

4. Data related to scan technique (including radiation dose reduction strategies).

5. Adverse events occurring during or immediately after the examination, attributable to contrast agent admin-istration, drug administration and/or the patient’s basal condition. Complications caused by acute adverse reactions to contrast media (i.e., within 60 min after administration) were defined according to the Ameri-can College of Radiology criteria.

Adverse events were scored as mild, moderate or severe using the following predefined criteria rea-dapted from Dorfman et al. [11]:

(a) Mild: transient change in condition, not life threatening and rapidly returning to baseline, required monitoring and/or minor intervention such as holding a medication, obtaining labora-tory test(s), etc.

(b) Moderate: transient change in condition, may be life threatening if not treated, returning to base-line if properly treated and required monitoring and/or intervention such as reversal agent, addi-tional medication or transfer to ICU.

(c) Severe: change in condition, life threatening if not treated and potentially permanent, may have required hospitalization or transfer to ICU, required monitor-ing and/or major intervention such as invasive pro-cedure, intubation, hemodynamic support and blood transfusion. In case of death, patients were excluded from the registry, recording the cause of the exitus.

6. Result of the examination according to the main clini-cal request (i.e., positive, negative or inconclusive).

7. Clinical impact on patient management (meaning therapeutic impact or requiring further management) which was assessed by the local reporting physician in consensus with patient’s referring physician and classi-fied as follows:

(a) non-diagnostic or inconclusive examination;(b) not relevant and without impact on patient’s man-

agement;(c) relevant but without impact on patient’s manage-

ment;(d) relevant with impact on patient’s management, con-

sisting of changes in the therapeutic (pharmacologi-cal or surgical) or diagnostic (further procedures performed) management and/or patient’s discharge or hospitalization following the examination.

8. Specialty (i.e., board certification) of the reading and reporting physician.

Data extraction

All data were collected via email on a monthly basis by trained personnel and manually stored in an electronic database provided by the University of L’Aquila for evalua-tion (Microsoft Excel® version 2007).

Statistical analysis

Since the objectives of this registry are descriptive in real-life scenarios, no formal hypothesis testing was carried out. Absolute numbers and percentages were computed to describe the patient population. Means (with standard devi-ation [SD]) were computed as appropriate to describe the patient population.

Results

The overall database of the present registry included 3,455 patients who underwent CCT during the study period. Of these 3,455 patients, 12 pediatric patients were separately examined to avoid extreme differences in BMI and dose exposition. The main working database therefore comprised 3,443 adult patients (60 ± 13 years; range 18–98 years). Most patients (2,269 [65.87 %]; gender data missing for 13 [0.3 %] patients) were male. The mean height and weight were 167 ± 14 cm (range 143–198 cm) and 76 ± 31 kg (range 44–190) kg, respectively (Table 1).

12 pediatric patients were also examined. Wide differ-ences in the body mass were present. For this reason, we divided these patients into two different groups (1–2, and 10–16 years old). The fist group was composed of two patients (13 and 23 months). The second group was com-posed of ten patients of age between 10 and 16 years; the mean age was 12.7 ± 2.1 years (Table 2).

We collected data from 47 different centers (27 centers in the north of the country, 11 centers in the central area and 9 centers in the south and islands). Therefore, the geo-graphic distribution of the patient population demonstrated a clear north-to-south gradient, with the largest proportion (2,050 [59.5 %]) of patients enrolled in the north, followed by central regions (942 [27.3 %]) and the south and islands (451 [13 %] patients).

Most (3,283 [95.35 %]) patients underwent CCT for non-urgent reasons. The mean CT examination was 90.2 ± 110.4 per center with large differences between each other; 12 centers performed more than 100 exami-nations, 5 more than 200 examinations and only 1 more than 500 examination in 6 months. Fewer than 5 % (160

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patients) of examinations were considered urgent in most cases for acute chest pain (64.8 %). Most examinations (2,537 [74 %] patients) were performed for outpatients. The remaining examinations were performed in a day hospital regimen (175 [5 %]) or for hospitalized patients (719 [20 %]). In 12 cases, this information was missing (Table 1). None of these studies were performed in the emergency department.

Clinical indications for the examination

The most frequent indications for CCT were suspected CAD (44.8 %), calcium scoring (9.6 %), follow-up post-angioplasty/stenting (8.3 %), follow-up post-CABG (7.5 %), assessment of cardiac anatomy, especially stud-ies of the pulmonary veins and atria (4.22 %), assessment of patients with known CAD (4.1 %) and acute chest pain

(1.99 %) (Fig. 1). Unknown and other indications were reported for 19.6 % of the patients

All the 12 pediatric patients were studied to evaluate congenital anomalies (Table 2).

In 2,658 (76.96 %) patients, calcium scoring was also performed; in 331 (9.6 %) patients, it was not performed, while information was not available for the remaining 454 (13.1 %) patients (Fig. 1).

Acquisition data

Most investigations (73.02 %) were performed with 64-slice scanners. A further 23.3 % of examinations were performed with 128-, 256- and 640-slice scanners. Only 114 examinations (3.2 %) were performed with 16-slice scanners (Fig. 2). The distribution of latest gen-eration scanners (128 or more slices) was equally divided between the north (3), center (2) and south/islands (2). Only one 640-slice scanner was present in our series. The “high pitch technique” (or “Flash”) was available in two centers.

Slightly more than half the population (1,732 [50.1 %] patients) underwent a stress test prior to CCT, while 1,658 (49.1 %) patients did not.

The mean dose length product (DLP) in investigations performed for calcium scoring was 264 ± 16.9 mGy; in 76.96 % of these investigations administration of IV con-trast material was performed.

Overall, contrast agent administration was performed in almost all patients (3,185 patients; 92.5 %). The mostly commonly used contrast material was iomeprol 400 mg/dl (76.1 %); the average contrast media (CM) volume was 87 ± 3 ml (range 30–180 ml) and the average flow rate 5 ± 0.6 ml/s (range 4–6.7 ml/s) (Table 3).

There was no relationship between the number of slices and flow rate, although a trend toward an inverse rela-tionship between number of slices and volume of CM administered was noted. The average volume of CM was 90 ± 1.6 ml for 16 slices, 75 ± 2.3 ml for 64 slices and 62 ± 1.7 ml for scanners with more than 64 slices. No rela-tionship between volume of CM and prospective or retro-spective gating was apparent.

The average heart rate during the examination was 72 ± 2.6 bpm (range 48–125 bpm). β-blockers or other negative chronotropic drugs were administered to 1,854 (53.67 %) patients. Retrospective ECG gating was used in 2,371 patients (68.86 %), while prospective ECG triggering was used in 1,014 patients (29.34 %) (Fig. 3).

Retrospective cardiac gating was utilized for all exami-nations performed on 16-slice scanners (mean DLP: 1,409 ± 13 mGy). Instead, retrospective cardiac gating was utilized in 69.9 % of patients on 64-slice scanners (mean DLP 887 ± 10.6 mGy), while prospective cardiac

Table 1 Demographics, clinical settings and type of CT technology

Missing data on gender in 13 patients (i.e., investigations)

Parameters Value

Population 3,443

Age (mean ± SD; range) 60 ± 13 (18–98 years)

Male 2,269 (65.87 %)

BMI (mean ± SD; range) 21.5 ± 21 (19.3–35.2)

Patient’s source

Outpatients 2,537 (74 %)

Hospitalized 719 (20 %)

Day hospital 175 (5 %)

Unknown 12(0.34 %)

Clinical priority

Emergency 160 (4.6 %)

Elective 3,283 (95.3 %)

Unknown 50 (1.53 %)

Previous stress test

Yes 1,732 (50,1 %)

No 1,658 (49.1 %)

Unknown

CT scanner

16 slices 114 (3.2 %)

32 slices 1 (0.02 %)

32 slices × 2 60 (1.7 %)

64 slices 2,520 (73.0 %)

64 slices × 2 83 (2.5 %)

128 slices 62 (1.8 %)

256 slices 353 (10.3 %)

128 slices × 2 122 (3.5 %)

320 slices × 2 66 (1.9 %)

32 × 2 Dual source 49 (1.41 %)

64 × 2 Dual source 87 (2.51 %)

Unknown 3 (0.08 %)

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triggering was used in 30.1 % of patients (mean DLP 379 ± 10.2 mGy).

The global mean DLP for 64-slice scanners was 616.94 ± 13.1 mGy. A lower radiation dose was observed when iterative reconstruction was used in association with prospective ECG triggering (mean DLP 155 ± 0.8 mGy) than when used in conjunction with retrospective ECG gating (574 ± 12.7 mGy). Moreover, a lower radiation dose was observed when iterative reconstruction in con-junction with prospective ECG triggering was used with low kilovoltage techniques (mean DLP 148 ± 8.6 mGy) (Fig. 4).

Overall, 73.2 % of investigations performed on scan-ners with >64 slices were performed with prospective ECG triggering and the mean DLP was 257 ± 35.8 mGy; the remaining 26.8 % of investigations were performed

with retrospective ECG gating and the mean DLP was 467 ± 58.9 mGy.

Prospective cardiac gating was used for all examinations performed with the 640-slice scanner and the mean DLP was 224.8 ± 83.5 on 65 patients examined (Table 4).

Flash technology was employed in 331 patients and the mean DLP was 231.2 ± 135.9 (Fig. 5).

Techniques for dose reduction were used in 1,779 (51.4 %) patients and no data were available in 465 cases (34.7 %). Prospective ECG triggering was used in 858 (24.8 %) examinations, low kilovoltage in 544 (15.7 %) examinations and iterative image reconstruction in 377 (10.9 %) examinations. The total mean DLP was 618 ± 4.3 mGy (range 63–2370 mGy).

Adverse clinical events occurred during or immediately after the procedure (<60 min) in 26 cases (0.75 %); 23 cases were described as mild and 3 as moderate. In 14 cases the adverse event was attributed to contrast agent adminis-tration (mild allergic reaction: nausea in 6 cases, skin rash in 2 cases, cough in 1 case, sneezing in 2 cases and itch-ing in 3 cases). The events were not attributed to just one contrast agent, but were noted across all contrast agents utilized without clear differences between each other, con-sidering the small number of cases reported. Injection site extravasation of the CM was reported for five patients and classified as mild adverse clinical event. In three cases, the adverse event was related to the patient’s clinical condition. It was classified as moderate adverse clinical event consist-ing of chest pain in two cases and vasovagal syncope with persisting reduced blood pressure in one. In four cases, the adverse event was unspecified. No severe adverse events or deaths were reported during or because of the CCT procedure.

Acquisition data of the pediatric patients are reported in Table 2.

Result of the examination and impact on patient management

The CCT examination reported pathological data in 43.2 % of cases. The final diagnosis obtained was considered clini-cally relevant in 45.3 % of the cases providing significant impact on clinical/therapeutic management (Table 5). In all of these cases, CT examination suggested medical, inter-ventional or chirurgical therapy adding useful data to the previous clinical end or instrumental data. Nevertheless in the majority of the patients (56.8 %), the absence of coro-nary diseases was able to exclude previous pathological suspects.

Overall, only 101 (2.9 %) examinations were non-diag-nostic and had no clinical relevance. Two of these non-diagnostic examinations were due to adverse events dur-ing the examination caused by drugs or the patient’s basal

Table 2 Pediatric patients (group I 1–2 years old, group II 10–16 years old)

I Group II Group

Mean age (years) 1.5 ± 0.7 12.7 ± 2.1

Mean height (cm) 80 ± 5 166.8 ± 12.7

Mean weight (kg) 10.5 ± 1.5 60.1 ± 13.4

Patient’s source Outpatients/hospital-ized 2

Outpatients/hospital-ized 3

CT scanner (slices) 128 128 (4 patients)64 (7 patients)16 (1 patient)

Mean DLP 123.5 ± 34.6 340.5 ± 8.4

Contrast agent Iopromide 370 Iopromide 370 (4 patients)

Iomeron 400 (6 patients)

Mean volume(ml) 25 ± 7 82 ± 17.7

Flow rate(ml/sec) 3 4.8 ± 0.7

Side effects None None

Fig. 1 Clinical indications for the cardiac CT

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condition. There was no relationship between non-diagnos-tic investigations and heart rate (mean HR in non-diagnos-tic cases 74 ± 0.6 bpm; range 60–94 bpm) and scanners with ≥64 slices. However, non-diagnostic examinations were more prevalent for 16-slice scanners (74 [73.26 %] patients).

Most inconclusive cases were due to poor patient com-pliance (38 %), though non-diagnostic examinations were recorded also in patients with good compliance (28.4 %).

The greatest clinical impact on patient management was reported for examinations conducted for CAD detection (46.8 % of the cases).

Calcium scoring results were considered useful for patient management in 69.4 % of cases.

Reporting physicians

Overall, 79.7 % (2,746) of the examinations were reported by radiologists, 16.3 % (557) by a physician with a double

board certification in radiology/cardiology and 4 % (140) by radiologists and cardiologists in consensus. In our series, cardiologists alone made up just 0.02 % of reporting physicians (only 1 case).

Discussion

This Italian CCT survey was designed to evaluate diffusion and geographic distribution of the various national centers performing the examination, recording scanner types, num-ber of slices, protocols adopted, safety profile and spectrum of clinical indications.

The registry represents a relatively large patient popu-lation recruited in a relatively short time interval (3,443 adult patients during a 6-month period of enrollment) and derived from the experience of 47 different centers dis-tributed throughout Italy, with a north-to-south “gradient” (2,050 examinations performed in 27 centers in the north

Fig. 2 No significant descending artery stenosis is evident in all these patients. a Obtained with a 16 slices CT, b with a 64 slices CT, c with a 128 slices CT, d with a 256 slices CT and e with a 640 slices CT

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of the country, 942 in 11 centers in the center and 451 in 9 centers in the south and islands),using multivendor equip-ment and contrast agents and covering variable levels of CCT expertise. The strength of the study lies in its open-access nature and absence of specific enrollment criteria.

Although cardiac CT was predominantly performed by radiologists, collaboration between radiologists and cardi-ologists was evident at a few sites. In the vast majority of cases (73.0 %), CCT was performed using scanners with 64 slices and these types of scanners were also the most com-mon of all in the national territory [12]. Only a small num-ber of centers used the latest scanner generation with 256 (single or dual source) and 640 slices [13, 14]. While the number of centers performing the examination was larger in the north, the distribution of the latest scanner generation was evenly divided across the country.

Our study showed that the number of slices was inversely proportional to radiation dose: in those cent-ers that used scanners with >64-slices the DLP was lower. This result was related to the different algorithms for dose reduction used: lower radiation doses were observed when prospective triggering or iterative reconstruction was used (when these techniques were combined, the mean DLP for 64-slice scanners was 155 ± 0.8 mGy).

The number of slices was also related to the amount of contrast agent used: scanners with ≥64 slices required 30 % less contrast agent as compared to 16-slice scanners.

These results also suggest that technical challenges and the higher cost of scanners are still perceived as major

drawbacks by most centers and that this limits their diffu-sion and utilization to only a few academic sites or centers dedicated to cardiac diseases.

Our data show that only 76.96 % of calcium scoring exams have been followed by an angiographic phase. This highlights a lack of clear agreement between centers. In some centers, calcium scoring was not performed prior to CT angiography which may reflect a desire to spare X-ray exposure [15].

The principal clinical indication for CCT in our regis-try was the assessment of patients with suspected CAD (44.8 %). This is in line with major indications for non-invasive tests for CAD detection and is explained by the perception of CCT as gatekeeper for CAD. In fact, CCT is mostly performed in patients with intermediate risk who previously underwent stress tests with uncertain or non-diagnostic results.

Our data also demonstrate that the CCT is indicated after previous correct clinical evaluations and other investiga-tions, such as stress tests to differentiate CAD suspicious; this main clinical condition may explicate why most of the patients undergoing CCT are outpatients (95.35 %).

Although CCT was performed for almost 2 % of patients with acute chest pain, the examination was not always considered urgent [16]. This aspect is difficult to under-stand, but could be partially explained by the difficulty in performing a cardiac CT examination in the acute phase around the Italian territory.

CCT has a high diagnostic performance in the follow-up of patients after CABG. Literature reports suggest that 64-slice CCT has a sensitivity of 97 % and a specificity of 100 % in detecting bypass occlusion [17–21]. This is prob-ably one of the reasons why our survey shows a high preva-lence of examinations performed for follow-up of CABGs.

CCT also provides a good structural assessment of the heart; in fact, in our registry the investigation was per-formed for this reason in 4.22 % of patients. In those cases, the examinations were performed mostly for the study of pulmonary veins and atria [22–24].

Finally in most of the cases (55.8 %), CT was useful to exclude the presence of disease avoiding the need of more invasive and expensive tests as coronary angiography [25].

Our patient cohort data confirm the good safety profile of CCT with only 26 (0.7 %) adverse events recorded dur-ing or immediately after the procedure. Importantly, none of the events were severe, serious or fatal. No adverse events occurred during examinations performed in emer-gency situations, confirming the good safety profile also in patients with compromised baseline conditions. Adverse contrast agent-related events occurred in 14 cases, but there was no direct relationship between type of contrast agent and the adverse event. In three cases the adverse event was ascribed to the severity of the patient’s baseline conditions.

Table 3 Technical parameters of the concerned radiation and con-trast material

Missing data in 18 patients (i.e., investigations)

Parameter Value

Radiation dose (DLP)

Total population (mean ± SD; range) 618 ± 43 mGy (63–2,371)

16 slice (mean ± SD) 1,409 ± 13 mGy

64 slice (mean ± SD) 616,94 ± 13.1 mGy

>64 slice (mean ± SD) 422 ± 21 mGy

Contrast agent 3,185 (92.1 %)

Type

Iobitridol 350 60 (1.73 %)

Iohexol 350 97 (2.8 %)

Iodixanol 320 75 (2.17 %)

Ioversol 320 2 (0.05 %)

Iopromide 370 325 (9.4 %)

Iomeprol 400 2,614 (76.1 %)

Unknown 268 (7.8 %)

Volume (mean ± SD) 86 ± 3 ml (7–180)

Flow rate (mean ± SD) 5 ± 0.7 ml/sec (1–6.7)

Side effects 26 (0.75 %)

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These data showed the quite large utilization of cardiac CT in the field of different cardiac pathologies. The main indication was related to the suspicion of CAD. Most of the cases did not show any significant pathological data and were able to exclude previous pathological suspicions (56.8 %). In 43.2 % of the studied patients, the data were considered pathological and the final diagnosis was clini-cally relevant in 45.3 % of the cases. It was consistent with changes in the therapeutic (pharmacological or surgical) or diagnostic (further procedures performed) management and/or patient’s discharge or hospitalization following the examination.

Moreover, the obtained cardiac CT data were useful to add data to the previous clinical end or instrumental data.

These data provide a substantial correct use of car-diac CT in Italy according to the guidelines and rec-ommendation provided by different scientific societies (4–6).

β-Blockers or other negative chronotropic drugs were administered in more than half of the patients (53.67 %). The data confirm the need to reduce the cardiac frequency in relation to the tube rotation velocity, to avoid movements artifacts. In fact, the mean HR in non-diagnostic cases was 74 ± 0.6 bpm. Moreover, the acquisition time was also related to non-diagnostic examination and it was more prevalent for 16-slice scanners. Overall, only 2.9 % exami-nations were non-diagnostic and 38 % of those were due to poor patient compliance. Form these data we can evalu-ate as correct the technical acquisition of cardiac CT in the studied group.

Fig. 3 128-row detector. In a the retrospective technique was used (2.8 mSv), instead the prospective gated acquisition was used (1.9 mSv) in b with the evidence of a slight misalignment af the mid-dle descending artery

Fig. 4 Prospective gating acquisition obtained with a 320-row detec-tor in a single heartbeat using iterative reconstruction at 1.3 mSv

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Our study has shown that CCT is a safe technique and that it is useful in patient management.

The main limitation of the study is related to the infor-mation of the outcome of these patients. In fact, no data were available in so short a period like the one considered for the registry participation. Moreover, no data about the

percentage of patient who underwent coronary angiography are present. Differences in the technologies and expertise also affect the homogeneity of the data; only five centers performed more than 40 examination per month.

Oslo missed information about specific changes in the management of the patients provided by the evidence of pathological findings on cardiac CT.

Finally, our study design did not include information on patient follow-up after contrast administration, thus excluding the possibility of identifying late contrast-related adverse reactions. However, such reactions have virtu-ally been eliminated by preventive measures in all patients requiring CT evaluation.

Conclusions

Our Italian registry revealed a wide diffusion and geo-graphic distribution of CCT-dedicated centers with more centers and investigations performed in the north as com-pared to the central and southern regions. CCT is mainly performed and reported by radiologists.

The limited incidence and low severity of adverse clini-cal events observed in our registry confirms that CCT has a good safety profile, similar to data reported elsewhere.

Our data also show that CCT is important in clinical management of patients.

The further research focus of CCT registries would prob-ably be systematic clinical follow-up of patients enrolled to analyze mid- and long-term implications of CCT findings,

Table 4 The percentage and radiation dose using prospective ECG acquisition and retrospective ECG acquisition with different scanners

Prospective ECG acquisition Retrospective ECG acquisition

16-slice scanner – 100 % (mean DLP 1,409 ± 13 mGy)

64-slice scanner 30.1 % (mean DLP 379 ± 10.2 mGy) 69.9 % (mean DLP 887 ± 10.6 mGy)

>64-slice scanner 73.2 % (mean DLP 257 ± 35.8 mGy) 26.8 % (mean DLP 467 ± 58.9 mGy)

Fig. 5 Flash technique also obtained in a single heartbeat at 1.5 mSv

Table 5 Results of the test and clinical impact

Calcium scoring CS, pulmonary veins and left atrium anatomy PVLAA, triple rule out TRO, suspected ischemic heart disease SIHD, known ischemic heart disease KIHD, follow-up coronary artery bypass graft FU-CABG, follow-up percutaneous coronary intervention FU-PCI

Clinical indications Non-pathologic findings Pathologic findings Clinically relevant Not clinically relevant

CS 266 (43.4 %) 55 (8.9 %) 23 (3.7 %) 23 (37.9 %)

PVLAA 74 (28.1 %) 55 (20.9 %) 58 (22.4 %) 28 (10.6 %)

TRO 43 (34.1 %) 20 (15.8 %) 46 (36.5 %) 8 (6.3 %)

SIHD 824 (29.1 %) 619 (21.8 %) 814 (28.8 %) 205 (7.2 %)

KIHID 40 (17.1 %) 76 (32.4 %) 57 (24.3 %) 15 (6.4 %)

FU-CABG 87 (16.5 %) 185 (35.3 %) 142 (26.9 %) 18 (3.4 %)

FU-PCI 107 (21.9 %) 144 (29.5 %) 118 (24.1 %) 20 (4.1 %)

Others 338 (27.33 %) 313 (25.2 %) 312 (25.1 %) 94 (7.6 %)

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providing wider understanding of its clinical role in the complex scenario of cardiovascular diseases.

Conflict of interest The authors declare no conflict of interest.

Ethical standards This article does not contain any studies with human participants or animals performed by any of the authors.

CCT Italian Registry Group

Rocco Donato*1, Filippo Zerboni*2, Silvia Tresoldi*3, Carlo Tessa*4, Marco Rengo*5, Giuseppina Manglaviti*6, Massi-miliano Danti*7, Federico Crusco*8, Lucia Carotti*9, Bruno Beomonte Zobel*10, Antonio Bernardini*11, Arnaldo Scar-dapane*12, Simone Banderali*13, Manlio Acquafresca*14, Luca Maria Carusi*15, Umberto Negro*16, Roberto Pri-otto*17, Francesco De Cobelli*18, Matteo Quarenghi*19, Silvia Paganoni*20, Francesco Secchi*21, Nicola Sforza*22, Domenico Lumia*23, Roberto De Rosa*24, Ernesto Bis-soli*25, Luca Olivotti*26, Giulio Barbiero*27, Maurizio Cen-tonze*28, Rodolfo Leurini*29, Roberto Malagò*30, Dario Pinto*31.

*1Azienda Ospedaliera Universitaria G. Martino Me IRCCS Policlinico San Donato, Radiology Unit, Mi.

*2Radiologia, Ospedale Saronno, Va.*3Ospedale San Paolo, Mi.*4Ospedale Verilia Camaiore,Lucca.*5ICOT Latina, Polo Pontino, Università Sapienza.*6Centro Diagnostico Italiano, MI.*7M.G. Vannini “Figlie di San Camillo”, Roma.*8Nuovo Ospedale San Giovanni Battista, Foligno, PG.*9Ospedale S. Croce, Fano, PU.*10Diagnostica per Immagini Università Campus Bio-

medico, Roma.*11Ospedale Civile Mazzini, Te.*12AUO Policlinico Consorziale, Bari.*13EO Ospedali Galliera, GE.*14Azienda Ospedaliera-Universitaria Careggi, FI.*15Ospedale San Giovanni di Dio, FI.*16ASUR 8 Civitanova Marche, MC.*17Osp S. Croce e Carle, FI.*18Radiologia IRCCS San Raffaele, MI.*19Policlinico, Monza.*20Ospedale Bolognini, Seriate, BG.*21IRCCS Policlinico San Donato, San Donato Milan-

ese, MI.*22San Giovanni Rotondo, FG.*23Circolo e Fondazione Macchi, Varese.*24Cliniche Riunite, Napoli.*25Ospedale Civile Città di Camposampietro, PD.*26Ospedale Santa Corona, Pietra Ligure, SV.*27Ospedale San Bassiano, Bassano del Grappa, VI.

*28Ospedale Santa Chiara, Trento.*29Ospedale Infermi, Rimini.*30Policlinico Universitario G. Rossi, Verona.*31Ricerche Radiologiche SRL, Molfetta, BA.

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