Coronary computed tomography and triple rule out CT in patients with acute chest pain and an intermediate cardiac risk profile. Part 1: Impact on patient management

Objective

To evaluate the impact of coronary CT angiography (coronary CTA) or “triple-rule-out” CT angiography (TRO-CTA) on patient management in the work-up of patients with acute chest pain and an intermediate cardiac risk profile.

Materials and methods

100 patients with acute chest pain and an intermediate cardiac risk for acute coronary syndrome (ACS) underwent coronary CTA or TRO-CTA for the evaluation of chest pain. Patients with a high and low cardiac risk profile were not included in this study. All patients with significant coronary stenosis >50% on coronary CTA underwent invasive coronary catheterization (ICC). Important other pathological findings were recorded. All patients had a 90-day follow-up period for major adverse cardiac events (MACE).

Results

Based on a negative coronary CTA 60 of 100 patients were discharged on the same day. None of the discharged patients showed MACE during the 90-day follow-up. Coronary CTA revealed a coronary stenosis >50% in 19 of 100 patients. ICC confirmed significant coronary stenosis in 17/19 patients. Among the 17 true positive patients, 9 underwent percutaneous coronary intervention with stent implantation, 7 were received intensified medical therapy, and 1 patient underwent coronary artery bypass surgery.A TRO-CTA protocol was performed in 36/100 patients due to elevated d-dimer levels. Pulmonary embolism was present in 5 patients, pleural effusion of unknown etiology in 3 patients, severe right ventricular dysfunction with pericardial effusion in 1 patient, and an incidental bronchial carcinoma was diagnosed in 1 patient.

Conclusion

Coronary CTA and TRO-CTA allow a rapid and safe discharge in the majority of patients presenting with acute chest pain and an intermediate risk for ACS while at the same time identifies those with significant coronary artery stenosis.     

Coronary computed tomography and triple rule out CT in patients with acute chest pain and an intermediate cardiac risk for acute coronary syndrome: Part 2: Economic aspects

Objective

To evaluate the economic impact of integrating coronary CT angiography (cCTA) or whole chest “triple-rule-out” CTA (TRO-CTA) in the work-up of patients with acute chest pain.

Materials and methods

100 consecutive emergency department patients with acute chest pain and an intermediate cardiac risk for ACS underwent cCTA or TRO-CTA (cCTA group). Diagnostic performance, rate and length of hospitalization, hospital costs, hospital reimbursement and hospital profit were analyzed. All findings were compared to those of 100 different patients with acute chest pain that were evaluated with a standard of care (SOC) diagnostic algorithm (SOC group) that did not include cCTA. Diagnostic performance (“safety”) of both algorithms was defined as the absence of major adverse cardiac events (MACE) over a 90-day follow-up period.

Results

In the cCTA group 60/100 patients were safely discharged at the same day. 19/100 patients were hospitalized due to significant coronary stenosis on cCTA, which was confirmed by invasive coronary catheterization (ICC) in 17/19 patients. Relevant non-coronary disease that led to hospitalization were found in 21 patients of the cCTA group. In the SOC group all patients were hospitalized. 87 of these hospitalized patients underwent ICC for exclusion of coronary artery stenosis. A significant coronary artery stenosis was found in only 25 of these patients. Within the cCTA group no patient suffered from MACE over the 90-day follow-up period. In the SOC group 2 patients were rehospitalized during the 90-day follow-up period due to recurrent chest pain and 1 patient because of a pseudoaneurym of the left femoral artery after ICC. The median hospital costs per patient were significantly lower in the cCTA group than in the SOC group (428.9€ vs. 1575.0€, p < 0.001). The median reimbursement of the cCTA group was less compared to the SOC group (589.8€ vs. 2412.1€, p < 0.001) and patients in the cCTA group gained less profit than patients in the SOC group (57.0€ vs. 448.4€, p < 0.001).

Conclusion

Integrating cCTA or TRO-CTA in a SOC algorithm can safely reduce the number of hospitalized patients and reduce total health care costs.     

MDCT angiography and coronary catheter angiography in patients with chest pain which is first

Back ground

In some patients suffering from chest pain, we must start by non-invasive coronary CT angiography (CCTA) to protect these patients from unnecessary invasive coronary catheter angiography (CCA).

Diagnostic value of MDCT angiography in assessment of coronary artery bypass graft

Purpose

To evaluate the diagnostic value of MDCT angiography in assessment of coronary bypass grafts. We studied 51 patients from April 2008 to October 2011. All patients gave written informed consent, and the study protocol was approved by the Institutional Review Board. 96 grafts including 35 left internal mammary artery (LIMA) grafts, 5 radial artery grafts, and 56 saphenous vein grafts (SVG) were assessed by 64-MDCT and the results were compared with conventional coronary angiography as reference standard.

Results

The diagnostic value of multi-detector computed tomography for graft occlusion was: 100% sensitivity, 100% specificity, 100% positive predictive value, and 100% negative predictive value. The diagnostic power of multi-detector computed tomography for stenosis of the graft anastomosis was: 100% sensitivity, 96% specificity, 87.5% positive predictive value, and 100% negative predictive value, and 96.4% accuracy.

Conclusion

Multi-detector computed tomography has become an alternative to coronary angiography to diagnose graft occlusion and stenosis after coronary artery bypass. In addition, multidetector CT has the added advantage over traditional angiographic evaluation of simultaneously allowing evaluation for alternate postoperative complications that may also manifest with chest pain and dyspnea, thereby mimicking recurrent angina.     

Role of 320-slice multislice computed tomography coronary angiography in the assessment of coronary artery stenosis

Objective

To evaluate the effectiveness of the multislice CT coronary angiography, as a non-invasive imaging tool in assessment of coronary artery stenosis.

Patients and methods

The study included 50 patients who were referred for MSCT coronary angiography followed by catheter coronary angiography. Patients with previous coronary bypass grafts and those with coronary stents were excluded. History of contrast allergy, renal impairment and severe chest conditions were exclusion criteria. The coronary angiographic CT studies were performed using a 320 CT scanner. The catheter coronary angiographic studies were performed via femoral arterial puncture. The results of CT angiography were compared with the gold standard catheter angiography.

Results

The positive predictive value and negative predictive value of MSCT coronary angiography in detection of coronary artery stenosis were 94% and 100%, respectively.

Conclusion

In conclusion, MSCT coronary angiography is a very helpful and rapid non-invasive coronary imaging modality that was able to detect and grade coronary artery stenosis better than other noninvasive examinations used to detect CAD, such as exercise stress testing. Due to its very high negative predictive value, it may eliminate the need for invasive coronary procedures in the presence of normal coronary imaging.     

Effect of a novel motion correction algorithm (SSF) on the image quality of coronary CTA with intermediate heart rates: Segment-based and vessel-based analyses

Purpose

To evaluate the effect of SnapShot Freeze (SSF) reconstruction at an intermediate heart-rate (HR) range (65–75 bpm) and compare this method with single-sector reconstruction and bi-sector reconstruction on segmental and vessel bases in retrospective coronary computed tomography angiography (CCTA).

Materials and methods

Retrospective electrocardiogram-gated CCTA was performed on 37 consecutive patients with HR between 65 and 75 bpm using a 64-row CT scanner. Retrospective single-sector reconstruction, bi-sector reconstruction, and SSF were performed for each patient. Multi-phase single-sector reconstruction was performed to select the optimal phase. SSF and bi-sector images were also reconstructed at the optimal phase. The images were interpreted in an intent-to-diagnose fashion by two experienced readers using a 5-point scale, with 3 points as diagnostically acceptable. Image quality among the three reconstruction groups were compared on per-patient, per-vessel, and per-segment bases.

Results

The average HR of the enrolled patients was 69.4 ± 2.7 bpm. A total of 111 vessels and 481 coronary segments were assessed. SSF provided significantly higher interpretability of the coronary segments than bi-sector reconstructions. The qualified and excellent rates of SSF (97.9% and 82.3%) were significantly higher than those of single-sector (92.9% and 66.3%) and bi-sector (90.9% and 64.7%) reconstructions. The image quality score (IQS) using SSF was also significantly higher than those of single-sector and bi-sector reconstructions both on per-patient and per-vessel bases. On per-segment analysis, IQS was improved in most segments (9/14).

Conclusion

The SSF algorithm can provide acceptable diagnostic image quality in coronary CTA for patients with intermediate HR.     

Diagnostic performance of 64-slice multidetector coronary computed tomographic angiography in women

Background

Diagnostic approach to chest pain in women is challenging, but still under-investigated. The purpose of this study was to assess the diagnostic performance of 64-slice multidetector coronary computed tomographic angiography (CCTA) in women with chest pain.

Methods and Results

We included 606 patients??255 women and 351 men (mean age 61?±?12?years for both)??who had been referred for a CCTA and an invasive coronary angiography (diagnostic standard) because of chest pain, either as part of clinical work-up in two urban medical centers or as part of the multicenter ACCURACY trial. On a patient-based model, the sensitivity, specificity, and positive predictive value (PPV) and negative predictive value to detect ??50% and ??70% stenosis were 98%, 84%, 87%, and 97% and 96%, 83%, 77%, and 97%, respectively, for women and 97%, 83%, 89%, and 95% and 94%, 91%, 90%, and 94%, respectively, for men. There were no statistically significant differences between men and women in diagnostic performance measures except for the PPV of detecting a ??70% stenosis (P?=?.007).

Conclusion

In women with chest pain, 64-slice multidetector CCTA is at least as sensitive and specific as in men. Our findings suggest that CCTA is a promising diagnostic tool for timely detection and/or exclusion of CAD in symptomatic intermediate-risk female populations.     

Improved diagnostic performance of transluminal attenuation gradient in combination with morphological evaluation of coronary artery stenosis using 320-row computed tomography

Purpose

To assess the utility of transluminal attenuation gradient (TAG) in combination with coronary computed tomography angiography (CTA) for detecting obstructive coronary artery stenosis.

Materials and methods

We retrospectively evaluated coronary CTA data in 35 consecutive patients who underwent invasive coronary angiography (ICA). We compared the diagnostic performance of TAG with that of quantitative coronary angiography, which we used as the reference standard. For the combination of TAG and coronary CTA, we designed a logical conjunction model (CCTA&&TAG) as well as a logical disjunction model (CCTA||TAG), and evaluated their diagnostic accuracies.

Results

Among 130 vessels of 35 patients, 30 lesions (23%) showed significant stenosis on ICA. TAG predicted significant coronary artery stenosis with a sensitivity of 75%, specificity of 63%, positive predictive value of 40%, negative predictive value of 89%, and accuracy of 66%, and had a cutoff value of ? 15.4 HU/10 mm. The respective values for CCTA&&TAG were 73, 98, 88, 90, and 90%; those for CCTA||TAG were 94, 61, 56, 94, and 72%. CCTA&&TAG improved the diagnostic accuracy significantly more than CCTA||TAG.

Conclusion

TAG in conjunction with coronary CTA improves the diagnostic accuracy of coronary CTA.

     

Cardiac MR enables diagnosis in 90% of patients with acute chest pain,elevated biomarkers and unobstructed coronary arteries

Objective:

To assess the diagnostic value of cardiac MRI (CMR) in patients with acute chest pain, elevated cardiac enzymes and a negative coronary angiogram.

Methods:

This study included a total of 125 patients treated in the chest pain unit during a 39-month period. Each included patient underwent MRI within a median of 3 days after cardiac catheterization. The MRI protocol comprised cine, oedema-sensitive and late gadolinium-enhancement imaging. The standard of reference was a consensus diagnosis based on clinical follow-up and the synopsis of all clinical, laboratory and imaging data.

Results:

MRI revealed a multitude of diagnoses, including ischaemic cardiomyopathy (CM), dilated CM, myocarditis, Takotsubo CM, hypertensive heart disease, hypertrophic CM, cardiac amyloidosis and non-compaction CM. MRI-based diagnoses were the same as the final reference diagnoses in 113/125 patients (90%), with the two diagnoses differing in only 12/125 patients. In two patients, no final diagnosis could be established.

Conclusion:

CMR performed early after the onset of symptoms revealed a broad spectrum of diseases. CMR delivered a correct final diagnosis in 90% of patients with acute chest pain, elevated cardiac enzymes and a negative coronary angiogram.

Advances in knowledge:

Diagnosing patients with acute coronary syndrome but unobstructed coronary arteries remains a challenge for cardiologists. CMR performed early after catheterization reveals a broad spectrum of diseases with only a simple and quick examination protocol, and there is a high concordance between MRI-based diagnoses and final reference diagnoses.Acute coronary syndrome (ACS) is a common working diagnosis in emergency and chest pain units worldwide. Acute chest pain is the cardinal symptom of an ACS, but clinical findings vary among patients, ranging from mild discomfort to severe cardiac arrhythmias and sudden cardiac death. Among all patients admitted to a hospital with acute chest pain, only 30% receive a final diagnosis of ACS.¹ This is reasonable owing to the multitude of differential diagnoses for troponin-positive acute chest pain ranging from ST-elevation myocardial infarction to non-cardiac aetiologies, such as pulmonary embolism and sepsis.^2,3In addition to the examination of clinical signs and symptoms, electrocardiogram (ECG) diagnostics and troponin measurements are routinely used in ACS evaluation. Standard 12-lead ECG is a key diagnostic tool for determining which patients with suspected acute myocardial infarction should be directed to the angiography suite.⁴ However, while ST elevations may indicate myocardial infarction, they can also be owing to other serious conditions, including pericarditis, myocarditis, cardiomyopathy (CM) and congestive heart failure. Moreover, ACS can be present even without ECG changes, for example, in cases of non-ST-elevation myocardial infarction (NSTEMI) or unstable angina pectoris.^3–5Cardiac troponin measurement, especially with implementation of highly sensitive assays, plays a central role in establishing a diagnosis and stratifying risk in patients with ACS.^6,7 However, aetiological diagnosis remains challenging in cases of troponin-positive acute chest pain with either normal coronary arteries or non-flow-limiting coronary artery disease. There are many possible responsible entities, such as clot lysis and recanalization of an acute thrombotic obstruction, coronary thromboembolism, acute myocarditis, apical ballooning syndrome, coronary vasospasm, inherited thrombophilia, non-ischaemic cardiomyopathies and non-cardiac aetiologies.^3,8Cardiac MRI (CMR) does not yet have a well-established role in patients with suspected ACS and is not part of the routine clinical work-up described in the current guidelines of the European Society of Cardiology.⁹ However, increasing evidence suggests that CMR may provide incremental diagnostic value in these patients.^10–13 We have adopted CMR in the diagnostic work-up of patients with suspected ACS.The present study aimed to investigate the diagnostic value of CMR in patients with suspected ACS. As a standard of reference, we used a consensus-based final diagnosis established using clinical follow-up of up to 3 months after admission and the synopsis of all clinical, laboratory and imaging findings.     

Prediction of the presence of renal artery stenosis by calcium scoring of the abdominal aorta

Objective

To establish a method for estimating the probability of renal artery stenosis (RAS) based on the calcium volume score of the aorta (ACS).

Materials and Methods

In a retrospective observation study, CT angiographies acquired on a 64-slice MDCT scanner were analyzed for 1351 patients (female: 531; male 826; mean age 60.9 ± 17.7 years). A volumetric scoring method was used, detecting plaques with a density of more than 600 HU.

Results

13.8% of the patients showed a stenosis >50%, 4.1% a stenosis >70%. The ACS was 0.61 ± 1.01 ml calcium. The sensitivity for detection of RAS >50% and RAS >80% was 0.9572 and 1.0, respectively. The negative predictive value (NPV) of a lack of calcification for excluding RAS >50% and RAS >80% was 0.9752 and 1, respectively. As ACS increased, the specificity for RAS >50% increased to 0.9390. With an ACS of 0.380 ml, accuracy reached a maximum of 0.6585. ROC analyses yielded an area under the curve of 0.88 (p < 0.0001). Sensitivity, specificity, NPV and PPV are indicated in relation to the degree of RAS, as well as the diagnostic yield of the method, which is valuable in patients older than 50 years.

Conclusion

Due to its extremely high sensitivity and NPV, the ACS is a very useful screening method for RAS. The validity of the method, as well as its diagnostic value is equivalent to that of coronary artery calcium scoring. Lack of calcifications of the aorta renders atherosclerotic RAS highly improbable.     

Differences in coronary artery disease by CT angiography between patients developing unstable angina pectoris vs. major adverse cardiac events

Objective

CT angiography (CTA) has prognostic value in patients. But it is unknown whether differences in atherosclerosis by CTA predict the development of unstable angina pectoris (UAP) vs. major adverse cardiac events (MACE).

Methods

We followed patients undergoing CTA as part of their acute chest pain work-up. Primary outcome was the development of UAP or MACE (cardiac death, myocardial infarction, revascularization) during a minimum follow-up of 12-months. CTAs were assessed for extent and composition of coronary plaque and stenosis. Ordinal regression with a 3-level outcome (no events, UAP, MACE) was applied.

Results

Among 315 patients, 22 developed UAP and 31 MACE. While UAP patients had higher atherosclerosis burden with respect to all assessed features compared to patients with no events (p ≤ 0.02), only mixed plaque extent was significantly different between UAP and MACE patients (p = 0.02). The odds ratio was 4.55 for being in a higher disease-level comparing patients with low extent to those with no mixed plaque, and 3.02 comparing patients with high to those with low. These findings remained after adjustments for potential confounders.

Conclusion

The extent of mixed coronary plaque is different between patients who develop UAP vs. MACE, supporting the hypothesis that it is a more culprit morphology.     

Value of conventional chest radiography for the detection of coronary calcifications: comparison with MSCT

Purpose

To evaluate if computed tomography (CT) coronary calcium scoring is needed after detection of coronary calcifications on conventional chest radiographs.

Materials and methods

One hundred and five patients (67 men; 57.2 ± 12.8 years) with suspected coronary artery disease underwent conventional chest radiography and non-enhanced, retrospectively ECG-gated multislice spiral CT (MSCT) of the heart (4 mm × 2.5 mm, 120 kV, 133 mAs_eff.). Chest radiographs were assessed independently by two radiologists. Detection of coronary calcifications was compared between both methods. Sensitivity, specificity, negative and positive predictive values, median, 25% and 75% percentiles for the detection of coronary calcifications were calculated. Receiver operating characteristics (ROC) analyses were computed.

Results

In 90 patients, MSCT revealed coronary calcifications. The mean coronary calcium score was 526.2 (0–4784.5). On chest radiographs, coronary calcifications were correctly detected in 46 (61) patients by observer 1 (observer 2). The corresponding sensitivity was 51.1% in observer 1 and 67.8% in observer 2. Median of detected coronary calcifications was 361.9 (426.4) for observer 1 (observer 2). Corresponding 25% und 75% percentiles were 109.6 (109.6) and 798.5 (898.5). The area under the ROC curve was 0.636 for observer 1 and 0.715 for observer 2. There was no correlation between image quality and the detection of coronary calcifications on plain film radiographs.

Conclusion

As coronary calcifications of various extents are inconsistently detected on plain chest radiographs, CT calcium scoring may not be omitted even if coronary artery calcifications were detected on conventional chest radiographs.     

Coronary artery calcium score and CT angiography in asymptomatic elderly patients with high pretest probability for coronary artery disease

Purpose

To evaluate the role of coronary artery calcium scoring (CACS) and/or coronary CT angiography (CCTA) in asymptomatic elderly patients with high pretest probability for coronary artery disease (CAD).

Materials and methods

Forty-eight consecutive asymptomatic elderly (>65 years) subjects who had a high pretest probability and underwent CACS/CCTA were included. Each CCTA was evaluated for adequacy for assessment of coronary stenosis. Significant stenosis (>50 % diameter narrowing) was assessed on evaluable CT images and by invasive catheter angiography (ICA).

Results

All subjects were men with mean CACS of 880 ± 1779. Among those with low (0–99), intermediate (100–399), and high (400–999) CACS, ICA-verified significant stenosis was present in 8 % (1/13), 23 % (2/13), and 67 % (8/12), respectively. Among those with very high CACS (≥1000) (n = 10), 90 % of CCTAs were not evaluable for stenosis.

Conclusion

In asymptomatic elderly subjects with high pretest probability, CACS followed by CCTA may be considered for those with intermediate to high CACS.

     

Sixty four multi-detectors CT coronary angiography: An easy and accurate method to detect graft patency post CABG

Objective

To assess the accuracy of coronary CTA in detection of coronary artery bypass graft patency, occlusion and stenosis.

Patients and methods

Twenty-four patients with past history of coronary bypass surgery were included in this study and underwent MDCT coronary angiography. Invasive coronary angiography was done within 2 weeks of MDCT coronary angiography. All grafts considered patent were then evaluated for the presence of significant stenosis. Significant stenosis was defined as reduction in diameter of more than 50%.

Results

All the MDCT scans were interpretable and a total number of 78 CABG conduits were analyzed. At MDCT angiography 4 (5.2%) grafts were classified as occluded and 74 (94.8%) grafts were patent. Significant stenosis was detected in 7 (9.4%) out of the 74 patent grafts. At invasive coronary angiography; when occlusion and significant stenosis pooled together they were 9 grafts; 4 arterial and 5 venous. All these 9 grafts were detected at MSCT (sensitivity is 100%). In 67 out of 69 grafts occlusion or significant stenosis was correctly ruled out (specificity 97.1%). The diagnostic accuracy of MDCT angiography when compared with invasive angiography was 97.4%. The negative predictive value was 100% and positive predictive value was 81.8%.

Conclusion

MDCT coronary angiography is an accurate imaging technique for the evaluation of CABG patency and in detection of graft stenosis and confirms of previous studies using 64 MDCT.     

<Emphasis Type="Bold">Discrepancies between coronary CT angiography and invasive coronary angiography with focus on culprit lesions which cause future cardiac events</Emphasis>

Objectives

To evaluate the clinical significance of discrepant lesions between coronary computed tomography angiography (CCTA) and invasive coronary angiography (ICA) in a longitudinal study.

Methods

In 220 patients with suspected coronary artery disease (CAD) who underwent both 256-row CCTA and ICA, the obstructive CAD (≥ 50% stenosis) on CCTA was compared with that on ICA as the reference standard. We analysed the causes of the discrepancy between CCTA and ICA. During a 40-month follow-up period, major adverse cardiac events (MACE) were assessed.

Results

Discordance between CCTA and ICA was observed in 121 of the 3166 coronary artery segments (3.8%). Common causes were calcification (45.9%) and positive remodelling (PR) (29.6%) in 83 false positive lesions, and noise (40.0%) and motion artefact (37.8%) in 38 false negative lesions. MACE occurred in seven lesions among the discrepant lesions; six among the 29 PR lesions (20.7%) and one among the 53 calcified lesions (1.9%). With respect to the prediction power of MACE in an intermediate stenosis, the CCTA-related value including PR was higher than the ICA-related value.

Conclusions

PR was a frequent cause of MACE among the false positive lesions on CCTA. Therefore, the presence of PR on CCTA may suggest clinical significance, although it can be missed by ICA.

Key Points

? Compared to ICA, PR in CCTA may be cause of false positive lesion. ? CCTA-related value including PR shows higher prediction power of MACE than ICA-related value. ? PR reflects atherosclerotic burden that can be related to cardiac events. ? PR in CCTA should be observed carefully, even if it is false positive.

     

Prognostic value of coronary atherosclerosis progression evaluated by coronary CT angiography in patients with stable angina

Objectives

To investigate the progression of coronary atherosclerosis burden by coronary CT angiography (CCTA) and to demonstrate its association with the incidence of major adverse cardiac events (MACE).

Methods

We retrospectively studied patients with stable angina who had undergone repeat CCTA due to recurrent or worsening symptoms. Lipid-rich, fibrous, calcified and total plaque burden as well as coronary diameter stenosis were quantitatively analysed. The incidence of MACE during follow-up was determined.

Results

The final cohort consisted of 268 patients (mean age 52.9 ± 9.8 years, 71 % male) with a mean follow-up period of 4.6 ± 0.9 years. Patients with lipid-rich, fibrous, calcified and total plaque burden (%) progression, as well as coronary diameter stenosis (%) progression had a significantly higher incidence of MACE than those without (all p < 0.05). The progression of lipid-rich plaque (HR = 1.601, p = 0.021), total plaque burden (HR = 2.979, p = 0.043) and coronary diameter stenosis (HR = 4.327, p <0.001) were independent predictors of MACE (all p < 0.05).

Conclusions

Patients presenting with recurrent or worsening symptoms associated with coronary artery disease who have coronary atherosclerosis progression on CCTA are at an increased risk of future MACE.

Key Points

? Repeat CCTA can provide information regarding the progression of coronary atherosclerosis. ? Coronary atherosclerosis progression at CCTA is independently associated with MACE. ? CCTA findings could serve as incremental predictors of MACE.

     

Negative predictive value of stress myocardial perfusion imaging and coronary computed tomography angiography: A meta-analysis

Background

Comparing the prognostic value of a negative finding by stress single-photon emission computed tomography myocardial perfusion imaging (MPI) and coronary computed tomography angiography (CCTA) may be useful to evaluate how better identify low-risk patients. We performed a meta-analysis to compare the long-term negative predictive value (NPV) of normal stress MPI and normal CCTA in subjects with suspected coronary artery disease (CAD).

Methods and Results

Studies published between January 2000 and November 2016 were identified by database search. We included MPI and CCTA studies that followed-up ≥100 subjects for ≥5 years and providing data on clinical outcome for patients with negative tests. Summary risk estimates for normal perfusion at MPI or <50% coronary stenosis at CCTA were derived in random effect regression analysis, and causes of heterogeneity were determined in meta-regression analysis. We identified 12 eligible articles (6 MPI and 6 CCTA) including 33,129 patients (26,757 in MPI and 6372 in CCTA studies) with suspected CAD. The pooled annualized event rate (AER) for occurrence of hard events (death and nonfatal myocardial infarction) was 1.06 (95% confidence interval, CI 0.49-1.64) in MPI and 0.61 (95% CI 0.35-0.86) in CCTA studies. The pooled NPV was 91% (95% CI 86-96) in MPI and 96 (95% CI 95-98) in CCTA studies. The summary rates between MPI and CCTA were not statistically different. At meta-regression analysis, no significant association between AER and clinical and demographical variables considered was found for overall studies.

Conclusions

Stress MPI and CCTA have a similar ability to identify low-risk patients with suspected CAD.

     

Efficiency and safety of coronary CT angiography compared to standard care in the evaluation of patients with acute chest pain: a Canadian study

The optimal assessment of patients with chest pain and possible acute coronary syndrome (ACS) remains a diagnostic dilemma for emergency physicians. Cardiac computed tomographic angiography (CCTA) may identify patients who can be safely discharged home from the emergency department (ED). The objective of the study was to compare the efficiency and safety of CCTA to standard care in patients presenting to the ED with low- to intermediate-risk chest pain. This was a single-center before-after study enrolling ED patients with chest pain and low to intermediate risk of ACS, before and after implementing a cardiac CT-based management protocol. The primary outcome was efficiency (time to diagnosis). Secondary outcomes included safety (30-day incidence of major adverse cardiovascular events (MACE)) and length of stay in the ED. We enrolled 258 patients: 130 in the standard care group and 128 in the cardiac CT-based management group. The cardiac CT group had a shorter time to diagnosis of 7.1 h (IQR 5.8–14.0) compared to 532.9 h (IQR 312.8–960.5) for the standard care group (p?<?0.0001) but had a longer length of stay in the ED of 7.9 h (IQR 6.5–10.8) versus 5.5 h (IQR 3.9–7.7) (p?<?0.0001). The MACE rate was 1.6 % in the standard care group and 0 % in the cardiac CT group. In conclusion, a cardiac CT-based management strategy to rule out ACS in ED patients with low- to intermediate-risk chest pain was safe and led to a shorter time to diagnosis but increased length of stay in the ED.     

Using coronary CT angiography for guiding invasive coronary angiography: potential role to reduce intraprocedural radiation exposure

Objectives

We investigated the potential reduction of patient exposure during invasive coronary angiography (ICA) if the procedure had only been directed to the vessel with at least one ≥ 50% stenosis as described in the CT report.

Methods

Dose reports of 61 patients referred to ICA because of at least one ≥ 50% stenosis on coronary CT angiography (CCTA) were included. Dose–area product (DAP) was documented separately for left (LCA) and right coronary arteries (RCA) by summing up the single DAP for each angiographic projection. The study population was subdivided as follows: coronary intervention of LCA (group 1) or RCA (group 2) only, or of both vessels (group 3), or further bypass grafting (group 4), or no further intervention (group 5).

Results

57.4% of the study population could have benefitted from reduced exposure if catheterization had been directly guided to the vessel of interest as described on CCTA. Mean relative DAP reductions were as follows: group 1 (n = 18), 11.2%; group 2 (n = 2), 40.3%; group 3 (n = 10), 0%; group 4 (n = 3), 0%; group 5 (n = 28), 28.8%.

Conclusions

Directing ICA to the vessel with stenosis as described on CCTA would reduce intraprocedural patient exposure substantially, especially for patients with single-vessel stenosis.

Key points

? Patients with CAD can benefit from decreased radiation exposure during coronary angiography. ? ICA should be directed solely to significant stenoses as described on CCTA. ? Severely calcified plaques remain a limitation of CCTA leading to unnecessary ICA referrals.

     

Incidence and classification of neointimal proliferation and in-stent restenosis in post-stenting patients at 1-year interval: Findings from non-invasive coronary computed tomography angiography

Objectives

To evaluate the incidence of coronary in-stent restenosis (ISR) and neointimal proliferation by coronary CT angiography (CCTA) at 1-year follow-up in asymptomatic patients.

Methods

234 patients (mean age: 67 ± 10.2 years, range 39–88 years, 180 males and 54 females) with 379 stents were prospectively enrolled in this study. Binary ISR was classified by CCTA into 4 types using Mehran classification. Neointimal proliferation was similarly classified into focal and diffuse types. All patients with CCTA-revealed ISR or neointimal proliferation underwent further invasive coronary angiography (ICA) for validation. Fisher's exact test was used for comparison.

Results

ICA revealed patent stents with neointimal proliferation in 39 patients (16.7%, 39/234) and binary ISR in 23 patients (9.8%, 23/234). Lesion-based analysis showed 12 type I ISR lesions, 4 type II ISR lesions, 1 type III ISR lesion and 7 type IV ISR lesions. Among cases with neointimal proliferation, 27 lesions were classified as focal type whereas 13 lesions were classified as diffuse type. Patients with diabetes mellitus were associated with higher incidence of CCTA-revealed neointimal proliferation (21/77 vs. 18/157, p = 0.002) as well as ISR (12/77 vs. 11/157, p = 0.038), compared to patients without diabetes. CCTA was found to have good diagnostic performance for neointimal proliferation and ISR detection as well as classification, with an overall accuracy of 84.4% (54/64).

Conclusions

Silent ISR as well as neointimal proliferation is not uncommon findings in asymptomatic post-stenting patients at 1-year interval, as revealed by CCTA. Patients with diabetes are prone to have higher incidence of neointimal proliferation.