Andrea Igoren Guaricci

Incremental value and safety of oral ivabradine for heart rate reduction in computed tomography coronary angiography

BACKGROUND Heart rate (HR) reduction is essential to achieve optimal image quality and diagnostic accuracy with computed tomography coronary angiography (CTCA). Administration of ivabradine could be an attractive alternative to beta-blockade to reduce HR. METHODS One-hundred-twenty-three patients referred for CTCA were prospectively enrolled. Patients were divided in two groups depending on the absence or presence of chronic beta-blockade treatment. Within the two groups patients were randomized to either no additional premedication or oral ivabradine for 5 days prior to CTCA. In presence of chronic beta-blockade therapy it was shifted to atenolol 50mg twice a day for 5 days prior to CTCA. HR and blood pressure were assessed at admission (T0), immediately before CTCA (T1) and during CTCA (T2). The target HR was <65 bpm. RESULTS Ivabradine significantly reduced HR during CTCA. Mean relative HR reduction was 15% for controls, 12% for chronic beta-blockade, 19% for ivabradine and 24% for both chronic beta-blockade and ivabradine at T2 (p for trend <0.001). The rate of patients who reached the target HR at T2 was 83% in controls, 71% with chronic beta-blockade, 97% with ivabradine and 97% with both (p for trend <0.05). The percentage of patients that needed additional IV beta-blockade at T1 decreased from 69% to 40% with ivabradine and 30% with both (p for trend <0.05). CONCLUSIONS Ivabradine is safe and effective in increasing the rate of patients at target HR and in reducing the need for additional IV beta-blockade in patients referred for CTCA.

Coronary Artery Disease: Diagnostic Accuracy of CT Coronary Angiography—A Comparison of High and Standard Spatial Resolution Scanning

PURPOSE To compare the image quality, evaluability, diagnostic accuracy, and radiation exposure of high-spatial-resolution (HR, 0.23-mm) computed tomographic (CT) coronary angiography with standard spatial resolution (SR, 0.625-mm) 64-section imaging in patients at high risk for coronary artery disease (CAD) by using invasive coronary angiography (ICA) as the reference method. MATERIALS AND METHODS Written informed consent was obtained from all patients, and the study protocol was approved by the institutional ethical committee. Patients at high risk for CAD (n = 184) who were scheduled for ICA were randomly assigned for study with SR (n = 91) or HR (n = 93) coronary CT angiography before they underwent ICA. To compare the two groups, the Student t test or Wilcoxon test were used to evaluate differences in continuous variables. The χ(2) test or Fisher exact test were used, as appropriate, for categorical data. The McNemar test was used to compare the diagnostic performance of coronary CT angiography versus that of ICA in each group. RESULTS HR coronary CT angiography showed a higher image quality score (3.7 vs 3.4, P < .001) and evaluability (97% vs 92%, P < .002). In a segment-based analysis, HR coronary CT angiography showed a higher specificity, positive predictive value, and accuracy in comparison with SR coronary CT angiography (98%, 91%, and 99% vs 95%, 80%, and 95%, respectively; P < .001). Moreover, HR coronary CT angiography showed a better agreement with ICA for calcified plaques compared with SR coronary CT angiography and ICA (83% vs 53%, P < .001). In a patient-based analysis, HR coronary CT angiography showed higher specificity and accuracy compared with SR coronary CT angiography (91% and 98% vs 46% and 92%, respectively; P < .01). No differences in radiation exposure were found between the two groups. CONCLUSION Improved evaluability and accuracy were seen with HR compared with SR coronary CT angiography of calcified coronary artery lesions, suggesting a potential use for this technology in patients at high risk for CAD.

CT coronary angiography and exercise ECG in a population with chest pain and low-to-intermediate pre-test likelihood of coronary artery disease

Objective To evaluate diagnostic accuracy of exercise ECG (ex-ECG) versus 64-slice CT coronary angiography (CT-CA) for the detection of significant coronary artery stenosis in a population with low-to-intermediate pre-test likelihood of coronary artery disease (CAD). Design Retrospective single centre. Setting Tertiary academic hospital. Patients 177 consecutive patients (88 men, 89 women, mean age 53.5±7.6 years) with chest pain and low-to-intermediate pre-test likelihood of CAD were retrospectively enrolled. Interventions All patients underwent ex-ECG, CT-CA and invasive coronary angiography (ICA). Main outcome measure A lumen diameter reduction of ≥50% was considered as significant stenosis for CT-CA. Ex-ECG was classified as positive, negative or non-diagnostic. Results were compared with ICA. Diagnostic accuracy of CT-CA and ex-ECG was calculated using ICA as the reference standard. A parallel comparative analysis using a cut-off value of 70% for significant lumen reduction was also performed too. Results ICA disclosed an absence of significant stenosis (≥50% luminal narrowing) in 85.3% (151/177) patients, single-vessel disease in 9.0% (16/177) patients and multivessel disease in 5.6% (10/177) patients. Prevalence of obstructive disease at ICA was 14.7% (26/177). Sensitivity, specificity, positive and negative predictive values at the patient level were 100.0%, 98.7%, 92.9%, 100%, respectively, for CT-CA and 46.2%, 16.6%, 8.7%, 64.1%, respectively, for ex-ECG. Agreement between CT-CA and ex-ECG was 20.9%. CT-CA performed equally well in men and women, while ex-ECG had a better performance in men. After considering the cut-off value of 70% for significant stenosis, the difference between CT-CA and ex-ECG remained significant (p<0.01), with a low agreement (21.5%). Conclusions CT-CA provides optimal diagnostic performance in patients with atypical chest pain and low-to-intermediate risk of CAD. Ex-ECG has poor diagnostic accuracy in this population. Concerns are related to risk of radiation dose versus the benefits of correct disease stratification.

Rationale and design of the PERFECTION (comparison between stress cardiac computed tomography PERfusion versus Fractional flow rEserve measured by Computed Tomography angiography In the evaluation of suspected cOroNary artery disease) prospective study

BACKGROUND Non-invasive stress tests are commonly used as gatekeepers to invasive coronary angiography (ICA) in patients with suspected coronary artery disease (CAD). New computed tomography angiography (CTA) techniques such as fractional flow reserve calculated by CTA (FFRCT) and stress myocardial computed tomography perfusion (CTP) have emerged as potential strategies to combine anatomical and functional evaluation of CAD in one technique. The aim of this study is to compare per-vessel diagnostic accuracy of FFRCT versus stress myocardial CTP for the detection of functionally significant coronary artery disease (CAD), using invasive FFR as the reference standard. METHODS Subjects with suspected CAD due to chest pain who have no contra-indications to FFRCT or stress myocardial CTP and who are referred for non-emergent, clinically indicated invasive coronary angiography (ICA), will be enrolled. A total of 300 subjects will be enrolled within 24 months. RESULTS The primary study endpoint will be the comparison of per-vessel diagnostic accuracy of CTA versus FFRCT versus stress myocardial CTP for the diagnosis of hemodynamically significant stenosis as defined by invasive FFR ≤0.80. CONCLUSIONS In the PERFECTION study, the comparison between FFRCT and stress myocardial CTP will provide understanding about which technology is more accurate for the diagnosis of functionally significant CAD.

Carotid intima media thickness and coronary atherosclerosis linkage in symptomatic intermediate risk patients evaluated by coronary computed tomography angiography

BACKGROUND There is a growing evidence that carotid intima media thickness (CIMT) is associated with coronary artery disease (CAD) and it should be used as a predictor of atherosclerotic burden of coronary arteries. However, these studies have been performed by using invasive coronary angiography (ICA) and in high-risk patients for CAD. The purpose of this study was to evaluate the correlation between CIMT by ultrasound and coronary atherosclerosis in symptomatic intermediate risk patients by coronary computed tomography angiography (CCTA). METHODS We enrolled 204 consecutive symptomatic patients (mean age: 61±10; men: 118) and intermediate risk for CAD. All patients underwent CIMT ultrasound evaluation and CCTA. Coronary artery calcium score (CACS), characteristics of plaques, severity of CAD, segment involvement score (SIS) and Gensinis score were assessed and compared with CIMT values. RESULTS CIMT has been proved as an independent predictor of a number of coronary artery plaques, overall number of mixed and remodeled plaques, presence of obstructive CAD, high SIS and Gensinis score (HR 1.2, CI 1.05-1.42, p 0.01; HR 1.2, CI 1.01-1.41, p 0.03; HR 9.0, CI 1.37-59.7, p 0.02; HR 21.0, CI 2.40-184, p<0.01; HR 1.2, CI 1.08-1.42, p<0.01; HR 1.2, CI 1.08-1.42, p<0.01, respectively). A cut-off value>1.3 was associated with a better positive and negative predictive value (100% and 69%) to predict the combined endpoint of presence and mixed and/or remodeled coronary artery plaques. CONCLUSIONS CIMT is an independent predictor of coronary atherosclerotic burden as detected by CCTA in symptomatic intermediate risk patients.

Functional Relevance of Coronary Artery Disease by Cardiac Magnetic Resonance and Cardiac Computed Tomography: Myocardial Perfusion and Fractional Flow Reserve

Coronary artery disease (CAD) is one of the leading causes of morbidity and mortality and it is responsible for an increasing resource burden. The identification of patients at high risk for adverse events is crucial to select those who will receive the greatest benefit from revascularization. To this aim, several non-invasive functional imaging modalities are usually used as gatekeeper to invasive coronary angiography, but the diagnostic yield of elective invasive coronary angiography remains unfortunately low. Stress myocardial perfusion imaging by cardiac magnetic resonance (stress-CMR) has emerged as an accurate technique for diagnosis and prognostic stratification of the patients with known or suspected CAD thanks to high spatial and temporal resolution, absence of ionizing radiation, and the multiparametric value including the assessment of cardiac anatomy, function, and viability. On the other side, cardiac computed tomography (CCT) has emerged as unique technique providing coronary arteries anatomy and more recently, due to the introduction of stress-CCT and noninvasive fractional flow reserve (FFR-CT), functional relevance of CAD in a single shot scan. The current review evaluates the technical aspects and clinical experience of stress-CMR and CCT in the evaluation of functional relevance of CAD discussing the strength and weakness of each approach.

Prognostic value of computed tomography coronary angiography in patients with chest pain of suspected cardiac origin

PurposeThe authors sought to determine the prognostic value of computed tomography coronary angiography (CTCA) in patients with acute chest pain (ACP).Materials and methodsA total of 145 consecutive patients (75 men; 64±12 years) with ACP were referred from the Emergency Department for CTCA, which was performed with a standard protocol using a 64-slice scanner. Patients were stratified according to the Morise clinical score (low, intermediate, high) and to the CTCA findings [absence of coronary artery disease (CAD), nonobstructive CAD, obstructive CAD]. Patients were followed up for the occurrence of major events: cardiac death, nonfatal myocardial infarction, unstable angina and revascularisation.ResultsOne hundred and twenty-seven (87.6%) patients were without a history of CAD, and 18 (12.4%) patients had a history of CAD. Obstructive CAD (>50% luminal narrowing) was detected in 35 (24%) patients; nonobstructive CAD (≤50% luminal narrowing) in 62 (43%) and absence of CAD in 48 (33%) patients. During a mean follow-up of 20±3 months, 20 events occurred (four hard events). Sixteen events (three hard events) occurred in patients without a history of CAD, and four events (one hard event) occurred in patients with a history of CAD. In patients with absence of CAD as detected by CTCA, the rate of events was 0%. At multivariate analysis, hypercholesterolaemia and obstructive CAD were significant predictors of events (p<0.05).ConclusionsAn excellent prognosis was observed in patients with ACP and normal CTCA. CTCA shows the potential for optimal stratification of patients with ACP.RiassuntoObiettivoScopo di questo lavoro è valutare il valore prognostico della angiografia coronarica mediante tomografia computerizzata (CTCA) in pazienti con dolore toracico acuto (ACP)Materiali e metodiCentoquarantacinque pazienti (75 maschi; 64±12 anni) consecutivi con ACP sono stati inviati a CTCA dal dipartimento di emergenza. La CTCA è stata effettuata con tecnica standard ed uno scanner a 64 strati. I pazienti sono stati stratificati secondo lo score di Morise (basso, intermedio, alto) e la CTCA (assenza di coronary artery disease [CAD], CAD non ostruttiva, CAD ostruttiva). I pazienti sono stati seguiti per l’occorrenza di eventi maggiori: morte cardiaca, infarto miocardico non fatale, angina instabile e rivascolarizzazioneRisultatiCentoventisette (87,6%) pazienti non avevano storia di CAD e 18 (12,4%) pazienti avevano storia di CAD. È stata rilevata CAD ostruttiva (riduzione del lume >50%) in 35 (24%) pazienti; CAD non ostruttiva (riduzione del lume ≤50%) in 62 (43%) pazienti e assenza di CAD in 48 (33%) pazienti. Durante un follow-up medio di 20±3 mesi, abbiamo riscontrato 20 eventi (4 eventi hard). Sedici eventi (3 eventi hard) si sono verificati in pazienti senza storia di CAD e 4 eventi (1 evento hard) si è verificato nei pazienti con storia di CAD. Nei pazienticon assenza di CAD secondo la CTCA la frequenza di eventi è stata pari allo 0%. All’analisi multivariata, l’ipercolesterolemia e la CAD ostruttiva sono risultati predittori significativi di eventi (p<0,05)ConclusioniNei pazienti con ACP la CTCA conferisce prognosi ottima alle coronarie esenti da CAD. La CTCA ha il potenziale per una ottimale stratificazione del rischio nei pazienti con ACP

Prognostic Benefit of Cardiac Magnetic Resonance Over Transthoracic Echocardiography for the Assessment of Ischemic and Nonischemic Dilated Cardiomyopathy Patients Referred for the Evaluation of Primary Prevention Implantable Cardioverter-Defibrillator Therapy.

Background—The aim of this study was to determine the prognostic benefit of cardiac magnetic resonance (CMR) over transthoracic echocardiography (TTE) in ischemic cardiomyopathy and nonischemic dilated cardiomyopathy patients evaluated for primary prevention implantable cardioverter–defibrillator therapy. Methods and Results—We enrolled 409 consecutive ischemic and dilated cardiomyopathy patients (mean age: 64±12 years; 331 men). All patients underwent TTE and CMR, and left ventricle end-diastolic volume, left ventricle end-systolic volume, and left ventricle ejection fraction (LVEF) were evaluated. In addition, late gadolinium enhancement was also assessed. All patients were followed up for major adverse cardiac events (MACE) defined as a composite end point of long runs of nonsustained ventricular tachycardia, sustained ventricular tachycardia, aborted sudden cardiac death, or sudden cardiac death. The median follow-up was 545 days. CMR showed higher left ventricle end-diastolic volume (mean difference: 43±22.5 mL), higher left ventricle end-systolic volume (mean difference: 34±20.5 mL), and lower LVEF (mean difference: −4.9±10%) as compared to TTE (P<0.01). MACE occurred in 103 (25%) patients. Patients experiencing MACE showed higher left ventricle end-diastolic volume, higher left ventricle end-systolic volume, and lower LVEF with both imaging modalities and higher late gadolinium enhancement per-patient prevalence as compared to patients without MACE. At multivariable analysis, CMR-LVEF ⩽35% (hazard ratio=2.18 [1.3–3.8]) and the presence of late gadolinium enhancement (hazard ratio=2.2 [1.4–3.6]) were independently associated with MACE (P<0.01). A model based on CMR-LVEF ⩽35% or CMR-LVEF ⩽35% plus late gadolinium enhancement detection showed a higher performance in the prediction of MACE as compared to TTE-LVEF resulting in net reclassification improvement of 0.468 (95% confidence interval, 0.283–0.654; P<0.001) and 0.413 (95% confidence interval, 0.23–0.63; P<0.001), respectively. Conclusions—CMR provides additional prognostic stratification as compared to TTE, which may have direct impact on the indication of implantable cardioverter–defibrillator implantation.

Coronary artery calcium score on low-dose computed tomography for lung cancer screening

AIM To evaluate the feasibility of coronary artery calcium score (CACS) on low-dose non-gated chest CT (ngCCT). METHODS Sixty consecutive individuals (30 males; 73 ± 7 years) scheduled for risk stratification by means of unenhanced ECG-triggered cardiac computed tomography (gCCT) underwent additional unenhanced ngCCT. All CT scans were performed on a 64-slice CT scanner (Somatom Sensation 64 Cardiac, Siemens, Germany). CACS was calculated using conventional methods/scores (Volume, Mass, Agatston) as previously described in literature. The CACS value obtained were compared. The Mayo Clinic classification was used to stratify cardiovascular risk based on Agatston CACS. Differences and correlations between the two methods were compared. A P-value < 0.05 was considered significant. RESULTS Mean CACS values were significantly higher for gCCT as compared to ngCCT (Volume: 418 ± 747 vs 332 ± 597; Mass: 89 ± 151 vs 78 ± 141; Agatston: 481 ± 854 vs 428 ± 776; P < 0.05). The correlation between the two values was always very high (Volume: r = 0.95; Mass: r = 0.97; Agatston: r = 0.98). Of the 6 patients with 0 Agatston score on gCCT, 2 (33%) showed an Agatston score > 0 in the ngCCT. Of the 3 patients with 1-10 Agatston score on gCCT, 1 (33%) showed an Agatston score of 0 in the ngCCT. Overall, 23 (38%) patients were reclassified in a different cardiovascular risk category, mostly (18/23; 78%) shifting to a lower risk in the ngCCT. The estimated radiation dose was significantly higher for gCCT (DLP 115.8 ± 50.7 vs 83.8 ± 16.3; Effective dose 1.6 ± 0.7 mSv vs 1.2 ± 0.2 mSv; P < 0.01). CONCLUSION CACS assessment is feasible on ngCCT; the variability of CACS values and the associated re-stratification of patients in cardiovascular risk groups should be taken into account.

Diagnostic accuracy of 64-slice computed tomography coronary angiography in a large population of patients without revascularisation: registry data on the impact of calcium score

PurposeThis study evaluated the diagnostic accuracy of computed tomography coronary angiography (CTCA) for detecting significant coronary artery stenosis (≥50% lumen reduction) at different coronary calcium score (CACS) values with conventional coronary angiography (CAG) as the reference standard.Material and methodsA total of 1,500 patients (928 men, mean age 58.2±12.5 years) in sinus rhythm who underwent CTCA (64-slice technology) and CAG were enrolled. Diagnostic accuracy and likelihood ratios (LR) of CTCA were evaluated against CAG for the total population and in different CACS classes (0; 1–10; 11–100; 101–400; 401–1,000; >1,000).ResultsThe prevalence of obstructive disease was 51% (23.5% single vessel; 27.5% multivessel; progressive increase from 17.9% to 94% through the CACS classes). In the per-patient analysis, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of CTCA were 99%, 92%, 94% and 99%, respectively. Per-patient analysis showed a worse PPV of CTCA (76–77%) in classes with low CACS (1–10/11–100). Per-patient LR were higher in classes with extreme CACS values (0 = LR+ 18.3 and LR− = 0.0; c1,000 = LR+ 17.0 and LR− = 0.0) with values always >7 for LR+ and <0.033 for LR− for all CACS classes.ConclusionsCTCA is a reliable diagnostic modality, with high sensitivity and NPV regardless of CACS.RiassuntoObiettivoObiettivo del nostro lavoro è stato valutare l’accuratezza diagnostica dell’angiografia coronarica non invasiva con tomografia computerizzata (CTCA) nell’individuazione delle stenosi coronariche significative (riduzione del lume coronarico ≥50%) confrontata con la coronarografia convenzionale (CAG) in base al valore di calcium score (CACS).Materiali e metodiSono stati inclusi 1500 pazienti (928 uomini, età media 58,2±12,5 anni) in ritmo cardiaco sinusale sottoposti a CTCA e CAG. L’accuratezza diagnostica è stata calcolata utilizzando la CAG come standard di riferimento. Sono state calcolate l’accuratezza diagnostica, i quozienti di probabilità (LR) per la popolazione totale e nelle differenti classi di CACS (0; 1–10; 11–100; 101–400; 401–1000; >1000).RisultatiLa prevalenza di malattia ostruttiva nella popolazione era del 51% (23,5% malattia mono-vasale; 27,5% multi-vasale; con aumento progressivo dal 17,9% al 94% nelle diverse classi di CACS). Nell’analisi per paziente la sensibilità, specificità, valore predittivo positivo e negativo della CTCA sono risultati 99%, 92%, 94%, 99%, rispettivamente. Nell’analisi per paziente la CTCA ha mostrato un valore predittivo positivo peggiore (76%–77%) nelle classi di CACS basso (1–10/11–100). I LR per paziente sono risultati più elevati nelle classi estreme di CACS (0, LR+=18,3 e LR−=0,0; >1000, LR+=17,0 e LR− =0,0) con valori sempre >7 per LR+ e <0,033 per LR−, per tutte le classi di CACS.ConclusioniLa CTCA è una metodica diagnostica affidabile con elevata sensibilità e valore predittivo negativo indipendentemente dal valore di CACS.