Assessment of left ventricular function with 16- and 64-slice multi-detector computed tomography

Association Between Major Adverse Cardiovascular Events and Left Ventricular Mass Index in Patients Who Have Undergone Coronary Computed Tomography Angiography: From the FU-CCTA Registry

Background

Left ventricular mass (LVM) is a predictor of future cardiovascular risk. We determined the association between LVM measured by coronary computed tomography angiography (CCTA) and the prognosis in patients who have undergone CCTA for screening of coronary artery disease (CAD).

Methods

We performed a prospective cohort study. Five hundred twenty consecutive patients who underwent CCTA at Fukuoka University Hospital (FU-CCTA registry) were enrolled. They were clinically suspected of having CAD or had at least one cardiovascular risk factor, and were a follow-up of up to 5 years. Equal to more than 50% of coronary stenosis as assessed by CCTA was diagnosed as CAD. Using CCTA, LVM index (LVMI), LV ejection fraction (LVEF), LV end-diastolic volume (LVEDV) and LV end-systolic volume were measured. The primary endpoint was major adverse cardiovascular events (MACEs: including all causes of death, ischemic stroke, acute myocardial infarction and coronary revascularization). The patients were divided into non-MACEs and MACEs groups.

Results

The non-MACEs and MACEs groups consisted of 478 and 42 patients, respectively. Percent of CAD in the MACEs group was significantly higher than that in the non-MACEs group. The MACEs group showed significantly higher LVMI and tended to have a lower LVEF and LVEDV than the non-MACEs group. Although LVMI was not associated with MACEs in all patients, LVMI was independently associated with MACEs in males (odd ratio: 1.018, 95% confidence interval: 1.002 - 1.035, P = 0.030), but not females.

Conclusions

Evaluation of LVMI by CCTA may be useful for predicting MACEs in males.

The estimation of left ventricular function using prospective ECG-triggered coronary CT angiography

BACKGROUND

Coronary computed tomography angiography (CCTA) is vital for diagnosing coronary artery disease; however, prospective ECG-triggered acquisition, minimizing radiation exposure, limits left ventricular (LV) ejection fraction (EF) evaluation. We aimed to assess the feasibility and utility of LVEF100msec, a new index for estimating LV function using volumetric changes during 100 msec within systole.

METHODS

This retrospective study analyzed patients who underwent prospective ECG-triggered CCTA with systolic acquisition between January 2015 and June 2022. The LVEF100msec was calculated using the maximum and minimum LV volumes among the three phases (300, 350, and 400 msec post-QRS) and expressed as a percentage. Patients were classified into normal, mild-moderately reduced, or severely reduced LV function categories based on the reference test. The LVEF100msec was compared among groups, and the optimal cutoff value of LVEF100msec for predicting severe LV dysfunction was investigated.

RESULTS

The study included 271 patients (median age ​= ​58 years, 52% male). LVEF was normal in 188 (69.4%), mild-moderately reduced in 57 (21.0%), and severely reduced in 26 (9.6%) patients. Median LVEF100msec value was 9.0 (6.7-12.6) for normal LV function, 4.7 (3.1-8.8) for mild-moderately reduced, and 2.9 (1.5-3.8) for severely reduced LV function. LVEF100msec values significantly differed among categories (p ​< ​0.001). The optimal LVEF100msec cutoff for severe LV dysfunction was 4.3%, with an AUC of 0.924, sensitivity of 88%, and specificity of 89%.

CONCLUSION

The LVEF100msec may serve as a valuable indicator of severe LV dysfunction.

Association Between the Presence of Coronary Artery Disease or Peripheral Artery Disease and Left Ventricular Mass in Patients Who Have Undergone Coronary Computed Tomography Angiography

Background

Left ventricular mass (LVM) is a critical marker of future cardiovascular risk. We determined the association between LVM measured by coronary computed tomography angiography (CCTA) and the presence of coronary artery disease (CAD) or peripheral artery disease (PAD) in patients who had undergone CCTA for screening of CAD.

Methods

We enrolled 1,307 consecutive patients (66 ± 12 years old, 49% males) who underwent CCTA for screening of CAD at the Fukuoka University Hospital (FU-CCTA registry), and either were clinically suspected of having CAD or had at least one cardiovascular risk factor. Patients with coronary stenosis of ≥ 50% by CCTA were diagnosed as CAD. Patients with an ankle brachial pressure index < 0.9 or who had already been diagnosed with PAD were considered to have PAD. Left ventricular mass index (LVMI), left ventricular ejection fraction (LVEF), end-diastolic volume (EDV) and end-systolic volume (ESV) were measured. The patients were divided into CAD (-) and CAD (+) or PAD (-) and PAD (+) groups.

Results

The prevalences of CAD and PAD in all patients were 50% and 4.8%, respectively. Age, %males, %hypertension (HTN), %dyslipidemia (DL), %diabetes mellitus (DM), %smoking and %chronic kidney disease in the CAD (+) group were significantly higher than those in the CAD (-) group. Age, %males, %HTN, %DM and %smoking in the PAD (+) group were significantly higher than those in the PAD (-) group. CAD was independently associated with LVMI (odds ratio (OR): 1.01, 95% confidence interval (CI): 1.01 - 1.02, P < 0.01) in addition to age, male, HTN, DL, DM, and smoking. PAD was also independently associated with LVMI (OR: 1.01, 95% CI: 1.0 - 1.02, P = 0.018) in addition to age, DM, and smoking.

Conclusions

LVMI determined by CCTA may be useful for predicting atherosclerotic cardiovascular diseases including both CAD and PAD, although there were considerable differences between %CAD and %PAD in all patients.

The Association Between the Use of Low-Slice Computed Tomography Machines and Downstream Care: Comparative Study of 16-Slice and 64-Slice Computed Tomography Angiography

Background

Although computed tomography (CT) studies on machines with more slices have reported higher positive and negative predictive values, the impact of using low-slice (16-slice) CT machines on downstream testing has not been well studied. In community outpatient settings, low-slice CT machines remain in use, although many hospitals have adopted higher-slice machines.

Objective

This study examines the association between the use of low-slice CT machines and downstream invasive testing in the context of the CT angiography of the neck.

Methods

Included health insurance claims pertained to adults with commercial or Medicare Advantage health plans who underwent the CT angiography of the neck. Site certification data were used to assign counts of slices to claims. Claims that were made in the 60 days after CT were examined for cervicocerebral angiography. The association between the number of slices and cervicocerebral angiography was evaluated by using a chi-square test and multivariate logistic regression.

Results

Claims for 16-slice CT had a 5.1% (33/641) downstream cervicocerebral angiography rate, while claims for 64-slice CT had a 3.1% (35/1125) rate, and a significant difference (P=.03) was observed. An analysis that was adjusted for patient demographics also found a significant relationship (odds ratio 1.64, 95% CI 1.00-2.69; P=.047).

Conclusions

The use of low-slice CT machines in the community may impact the quality of care and result in more downstream testing.

The Potential Role of Cardiac CT in the Evaluation of Patients With Known or Suspected Cardiomyopathy: From Traditional Indications to Novel Clinical Applications

After 15 years from its advent in the clinical field, coronary computed tomography (CCTA) is now widely considered as the best first-step test in patients with low-to-moderate pre-test probability of coronary artery disease. Technological innovation was of pivotal importance for the extensive clinical and scientific interest in CCTA. Recently, the advent of last generation wide-coverage CT scans paved the way for new clinical applications of this technique beyond coronary arteries anatomy evaluation. More precisely, both biventricular volume and systolic function quantification and myocardial fibrosis identification appeared to be feasible with last generation CT. In the present review we would focus on potential applications of cardiac computed tomography (CCT), beyond CCTA, for a comprehensive assessment patients with newly diagnosed cardiomyopathy, from technical requirements to novel clinical applications.

Simultaneous Assessment of Left Ventricular Function and Coronary Artery Anatomy by Third-generation Dual-source Computed Tomography Using a Low Radiation Dose

BACKGROUND

To assess left ventricular function and coronary artery simultaneously by third-generation dual-source computed tomography (CT) using a low radiation dose.

METHODS

A total of 48 patients (36 men, 12 women; mean age 57.0 ± 9.5 years) who underwent both electrocardiography-gated cardiac CT angiography (CCTA) using 70–90 kVp and echocardiography were included in this retrospective study. The correlation between left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), and left ventricular ejection fraction (LVEF) measured using CCTA and echocardiography was determined. The quality of coronary artery images was analyzed using a 4-point scale (1, excellent; 4, poor). The effective radiation dose of CCTA was calculated.

RESULTS

Mean heart rate during the CT examination was 59.9 ± 9.9 bpm (range 38–79) and the body mass index of 48 patients was 24.5 ± 2.6 kg/m² (range 17.0–29.4). LVEDV, LVESV, and LVEF measured using CCTA and echocardiography demonstrated a fair to moderate correlation (Pearson correlation coefficient: r = 0.395, p = 0.005 for LVEDV; r = 0.509. p < 0.001 for LVESV; r = 0.551, p < 0.001 for LVEF). Average image quality score of coronary arteries was 1.0 ± 0.1 (range 1–2). A total of 99.0% (783 of 791) of segments had an excellent image quality score, and 1.0% (8 of 791) of segments had a good score. Mean effective radiation dose was 2.2 ± 0.7 mSv.

CONCLUSIONS

Third-generation dual-source CT using a low tube voltage simultaneously provides information regarding LV function and coronary artery disease at a low radiation dose. It can serve as an alternative option for functional assessment, particularly when other imaging modalities are inadequate.

Assessment of left ventricular ejection fraction using low radiation dose computed tomography

BACKGROUND

Cardiac CT is a non-invasive modality with the ability to estimate LVEF. However, given its limited temporal resolution and radiation, there has been initial resistance to use CT to measure LVEF. Developing an accurate, fast, low radiation dose protocol is desirable.

OBJECTIVE

The objective of this study is to demonstrate that a 'low radiation dose' 64 slice cardiac computed tomography (CT) protocol is feasible and can accurately measure left ventricular ejection fraction (LVEF) while delivering a radiation dose lower than radionuclide angiography (RNA).

METHODS

Patients undergoing RNA were prospectively screened and enrolled to undergo a 'low-dose' 64 slice CT LVEF protocol. LVEF measures, duration of each study and radiation dose between CT and RNA were compared.

RESULTS

A total of 77 patients (mean age = 61.8 ± 12.2 years and 58 men) were analyzed. The mean LVEF measured by CT and RNA were 41.9 ± 15.2% and 39.4 ± 13.9%, respectively, (P = 0.154) with a good correlation (r = 0.863). Bland-Altman plot revealed a good agreement between the CT and RNA LVEF (mean difference of -2.4). There was good agreement between CT LVEF and RNA for identifying patients with LVEF ≤30% (kappa = 0.693) and LVEF ≥50% (kappa = 0.749). The mean dose estimated effective dose for CT and RNA were 4.7 ± 1.6 and 9.5 ± 1.0 mSv, respectively. The mean CT LVEF imaging duration (4:32 ± 3:05 minutes) was significantly shorter than the RNA image acquisition time (9:05 ± 2:36 minutes; p < 0.001).

CONCLUSION

The results of our study suggest that low-dose CT LVEF protocol is feasible, accurate, and fast while delivering a lower radiation dose than traditional RNA.

Accuracy of multi-slice computed tomography for measurement of left ventricular ejection fraction compared with cardiac magnetic resonance imaging and two-dimensional transthoracic echocardiography: a systematic review and meta-analysis

BACKGROUND

Multi-slice computed tomography (MSCT) allows non-invasive assessment of the coronary arteries and simultaneously can provide measurement of left ventricular ejection fraction (LVEF). The accuracy of newer MSCT generations (64-slice or more) for assessment of LVEF compared with magnetic resonance imaging (MRI) and two-dimensional transthoracic echocardiography (TTE) has not been evaluated in a meta-analysis.

PURPOSE

To evaluate, via a systematic literature review and meta-analysis, whether MSCT can assess LVEF with high accuracy compared with MRI and TTE.

METHODS

Electronic databases and reference lists for relevant published studies were searched. Twenty-seven eligible studies provided mean LVEF% with its standard deviation (SD) measured by MSCT versus MRI and TTE. Meta-analysis of weighted mean difference (WMD) and Bland-Altman method were used to quantify the mean difference and agreement between MSCT compared with MRI and TTE.

RESULTS

The results of combining 12 studies showed no significant difference in LVEF% between MSCT and MRI with a WMD of -0.11 (-1.48, 1.26, 95% CI), p=0.88. Bland-Altman analysis showed excellent agreement between MSCT and MRI with a bias of 0.0 (-3.7, 3.7 ± 1.96SD) with 95% CI. The results of combining 15 studies showed no significant difference in LVEF between MSCT versus TTE measurements with a WMD of 0.19 (-1.13 to 1.50; 95% CI), p=0.87. Bland-Altman analysis showed excellent agreement between MSCT and TTE with a bias of 0.3 (-4.7, 5.7 ± 1.96SD) with 95% CI.

CONCLUSION

The newer MSCT generations can provide accurate LVEF measurement compared to MRI and TTE. MSCT represents a valid technique for the combined evaluation of LVEF and coronary artery disease.

Left and right ventricle assessment with Cardiac CT: validation study vs. Cardiac MR

Objectives

To compare Magnetic Resonance (MR) and Computed Tomography (CT) for the assessment of left (LV) and right (RV) ventricular functional parameters.

Methods

Seventy nine patients underwent both Cardiac CT and Cardiac MR. Images were acquired using short axis (SAX) reconstructions for CT and 2D cine b-SSFP (balanced-steady state free precession) SAX sequence for MR, and evaluated using dedicated software.

Results

CT and MR images showed good agreement: LV EF (Ejection Fraction) (52 ± 14% for CT vs. 52 ± 14% for MR; r = 0.73; p > 0.05); RV EF (47 ± 12% for CT vs. 47 ± 12% for MR; r = 0.74; p > 0.05); LV EDV (End Diastolic Volume) (74 ± 21 ml/m² for CT vs. 76 ± 25 ml/m² for MR; r = 0.59; p > 0.05); RV EDV (84 ± 25 ml/m² for CT vs. 80 ± 23 ml/m² for MR; r = 0.58; p > 0.05); LV ESV (End Systolic Volume)(37 ± 19 ml/m² for CT vs. 38 ± 23 ml/m² for MR; r = 0.76; p > 0.05); RV ESV (46 ± 21 ml/m² for CT vs. 43 ± 18 ml/m² for MR; r = 0.70; p > 0.05). Intra- and inter-observer variability were good, and the performance of CT was maintained for different EF subgroups.

Conclusions

Cardiac CT provides accurate and reproducible LV and RV volume parameters compared with MR, and can be considered as a reliable alternative for patients who are not suitable to undergo MR.

Key Points

• Cardiac-CT is able to provide Left and Right Ventricular function.

• Cardiac-CT is accurate as MR for LV and RV volume assessment.

• Cardiac-CT can provide accurate evaluation of coronary arteries and LV and RV function.

Electronic supplementary material

The online version of this article (doi:10.1007/s00330-011-2345-6) contains supplementary material, which is available to authorized users.

Effects of propranolol on the left ventricular volume of normal subjects during CT coronary angiography

OBJECTIVE

The purpose of this study is to determine the effects of propranolol on the left ventricular (LV) volume during CT coronary angiography.

MATERIALS AND METHODS

The LV volume of 252 normal Chinese subjects (126 subjects with propranolol medication and 126 age- and gender-matched Chinese subjects without medication) was estimated using 64 slices multi-detector CT (MDCT). The heart rate difference was analyzed by the logistic linear regression model with variables that included gender, age, body height, body weight, systolic blood pressure (SBP), diastolic blood pressure (DBP) and the dosage of propranolol. The following global LV functional parameters were calculated: the real-end diastolic volume (EDV), the real-end systolic volume (ESV) and the real-ejection fraction (EF).

RESULTS

The female subjects had a greater decrease of heart rate after taking propranolol. The difference of heart rate was negatively correlated with the dosage of propranolol. The real-EDV, the real-ESV and the real-EF ranged from 48.1 to 109 mL/m², 6.1 to 57.1 mL/m² and 41% to 88%, respectively. There was no significant difference in the SBP and DBP between the groups without and with propranolol medication (123 ± 17 and 80 ± 10 mmHg; 120 ± 14 and 80 ± 11 mmHg, respectively). The real-EDV showed no significant difference between these two groups, but the real-ESV and real-EF showed significant differences between these two groups (69.4 ± 9.3 and 70.6 ± 8.9 mL/m²; 23.5 ± 5.7 and 25.6 ± 3.7 mL/m², 66.5 ± 5.1% and 63.5 ± 4.6%, respectively).

CONCLUSION

The difference of heart rate is significantly influenced by gender and the dosage of propranolol. Propranolol will also increase the ESV, which contributes to a decreased EF, while the SBP, DBP and EDV are not statistically changed.

Left ventricular ejection fraction impact on contrast opacification of coronary artery bypass grafts in 64-slice multidetector computed tomography angiography

OBJECTIVE

The objective of the study was to find whether changes in left ventricular ejection fraction (LVEF) have an impact on contrast opacification of coronary artery bypass grafts (CABGs) in coronary computed tomography angiography (CTA).

METHODS

One hundred two CABG patients were assessed using 64-slice CTA. Concurrently, their LVEF was measured using computed tomography. Density of grafts were measured, and their correlation with parameters including LVEF determined.

RESULTS

A total of 253 grafts including 89 left internal mammary artery (LIMA) grafts, 41 saphenous vein grafts (SVGs) to diagonal artery, 66 SVGs to obtuse marginal (OM) artery, and 57 SVGs to posterior descending artery (PDA) were patent and assessed. Mean measured LVEF was 49% (SD, 7%). Mean attenuation value of the LIMA grafts was 302.39 (SD, 91.16) Hounsfield units (HU), and those of SVGs to diagonal artery, SVGs to OM artery, and SVGs to PDA were 348.73 (SD, 100.38) HU, 326.95 (SD, 101.41) HU, and 339.50 (SD, 111.67) HU, respectively. A significant negative correlation was found between LVEF and mean attenuation values of LIMA graft (P < 0.001; r = -0.80), SVG to diagonal artery (P < 0.001; r = -0.66), SVG to OM artery (P < 0.001; r = -0.75), and SVG to PDA (P < 0.001; r = -0.76).

CONCLUSIONS

A negative correlation was found between density of grafts and LVEF of CABG patients, which is usually echocardiographically assessed before CTA.

Quantification of aortic regurgitant fraction and volume with multi-detector computed tomography comparison with echocardiography

RATIONALE AND OBJECTIVES

Evaluate quantification of the aortic regurgitant fraction and volume with computed tomography (CT).

MATERIALS AND METHODS

Fifty-three patients with aortic regurgitation (AR) and 29 controls were examined with 64-multi-detector CT coronary angiography and transthoracic echocardiography (TTE). A dedicated software algorithm employing three-dimensional segmentation of left ventricle (LV) and right ventricle (RV) volumes and LV mass was applied. AR volume and fraction was calculated based on RV and LV stroke volumes (SV) and compared with echocardiography. The aortic regurgitant orifice area (ROA) was measured by CT.

RESULTS

A good correlation of the AR fraction and AR volume determined by CT compared to echocardiography was found for mild, moderate, and severe AR with 14.2% ± 9, 28.8% ± 8, and 57.9% ± 9 (r = 0.95, P < .001) for AR fraction, and 15.7 mL ± 11.33 mL ± 14, and 98.9 mL ± 36 for AR volume (r = 0.92, P < .0001), respectively. CT correctly classified severity of AR in 93% of patients based of AR-fraction, and in 89% based on AR volume. The sensitivity and specificity of CT were 98% and specificity 90.3%. The specificity improved to 97%, if the ROA by CT was added as diagnostic criterion.

CONCLUSION

Aortic regurgitation fraction and volume can be accurately quantified from CT coronary angiography datasets. These parameters can assist clinical management, e.g. in case of pending cardiac surgery decision.

Assessment of left ventricular ejection fraction and regional wall motion with 64-slice multidetector CT: a comparison with two-dimensional transthoracic echocardiography

The aim of this study was to compare the measurement of left ventricular ejection fraction (LVEF) and regional wall motion using 64-slice multidetector CT (MDCT) with that using two-dimensional transthoracic echocardiography (2D-TTE) in a heterogeneous patient population. In 126 patients with angina pectoris, acute myocardial infarction, chronic myocardial infarction, atypical chest pain without coronary artery disease or valvular heart disease, 64-slice MDCT was performed using retrospective electrocardiography gating without dose modulation. 20 phases of the cardiac cycle were analysed to identify the end-diastolic and end-systolic phases and to assess regional LV wall motion. For these measurements, 2D-TTE served as the reference standard. MDCT and 2D-TTE were performed within 10 days of each other. An excellent correlation between MDCT and 2D-TTE was shown for the evaluation of LVEF (59.2+/-11% vs 57.9+/-10%, respectively; r = 0.87). LVEF was slightly overestimated by MDCT, when compared with 2D-TTE, by an average of 1.4+/-5.6%. Good agreement was obtained between the use of the two techniques, with 94% of the segments scored identically on both modalities (kappa = 0.70). MDCT had a sensitivity of 97% and a specificity of 82% when compared with 2D-TTE as the reference standard. In conclusion, the use of 64-slice MDCT can provide comparable results to those using 2D-TTE for LVEF and regional wall motion assessment in a heterogeneous population.

Real-time three-dimensional echocardiographic left ventricular systolic assessment: side-by-side comparison with 64-slice multi-detector cardiac computed tomography

AIMS

To investigate by real-time 3D echocardiography (RT3DE) and cardiac computed tomography (CCT) the analysis of left ventricle ejection fraction (LVEF) and volumes.

METHODS AND RESULTS

A total of 67 patients (37 males, 55 +/- 11 years) were studied prospectively by RT3DE and by 64-slice CCT. RT3DE data: LVEF ranged from 30 to 78.6% (63.1 +/- 7.33); left ventricular end-diastolic volume (LVEDV) from 44.1 to 210 (104.9 +/- 29.7) mL; left ventricular end-systolic volume (LVESV) from 11.4 to 149 ( 38.9 +/- 19.3) mL. CCT data: LVEF ranged from 28 to 86% (66 +/- 8.4); LVEDV from 51 to 212 (110.3 +/- 31.2) mL; LVESV from 7 to 152 (38.2 +/- 19.2) mL. Correlations relative to RT3DE and CCT were: LVEF (r: 0.79, P < 0.0001); LVEDV (r: 0.82, P < 0.0001); and LVESV (r: 0.91, P < 0.0001).

CONCLUSION

It was observed adequate correlation between RT3DE and CCT ventricular systolic function and geometry assessment.