Diagnostic accuracy of low-dose dual-source cardiac computed tomography as compared to surgery in univentricular heart patients

Early superior cavopulmonary connection with pre-operative CT shows comparable outcomes for infants following norwood palliation

OBJECTIVES

There is increasing evidence that performing superior cavopulmonary connection at 3 months reduces mortality: reducing the risky 'interstage' period, volume off-loading the ventricle and reducing coronary steal, hopefully preserving ventricular function. Our objective was to describe our experience of early superior cavopulmonary connection with preoperative CT assessment compared to later connection at 6 months.

METHODS

Patients undergoing Norwood procedure from 2005 to 2020 were divided into Two eras were described and compared. Era 1 from 2005-2016 when superior cavopulmonary connection was undertaken at 6 months: and era 2 (2017-2020) when an earlier operation was performed. Demographics, mortality (interstage, early and late following superior cavopulmonary connection) and data on post-operative course and complications were recorded.

RESULTS

In era 1, 191 patients underwent Norwood (120 survivors to superior cavopulmonary connection) and 28 patients (23 survivors) in era 2. There were no significant differences in the demographics. Interstage mortality was 17.8% in era 1 and 8.0% in era 2 but not significantly significant (p = 0.22). The median (IQR) age at pre-imaging and superior cavopulmonary connection was significantly lower: 99 (81-120) vs 77 (47-102) days and 175 (117-208) vs 106 (102-122) day in era 1 vs era 2 (P < 0.005). Weight was lower at superior cavopulmonary connection in era 2 (mean (SD) 6.2 kg (1.2) vs 5.1 kg (0.8), p < 0.05). Intubation time and total length of stay were not statistically different. Median Intensive care unit stay was statistically significantly longer, but not clinically significant): 2.5 (2-4) vs 3 (3-5) days respectively (p < 0.05). There was no significant difference in early or late mortality, rates of diagnostic or interventional catheter, post-operative MRI/CT or stroke. Logistic regression analysis demonstrates increasing age at superior cavopulmonary connection was associated with increased chance of stroke or early death (p = 0.043).

CONCLUSIONS

Early superior cavopulmonary connection with CT assessment is feasible and although intensive care unit length of stay was slightly longer there was no change in the overall length of stay and no change in post-operative mortality or complications.

Variation in Advanced Diagnostic Imaging Practice Patterns and Associated Risks Prior to Superior Cavopulmonary Connection: A Multicenter Analysis

Single ventricle patients typically undergo some form of advanced diagnostic imaging prior to superior cavopulmonary connection (SCPC). We sought to evaluate variability of diagnostic practice and associated comprehensive risk. A retrospective evaluation across 4 institutions was performed (1/1/2010-9/30/2016) comparing the primary modalities of cardiac catheterization (CC), cardiac magnetic resonance (CMR), and cardiac computed tomography (CT). Associated risks included anesthesia/sedation, vascular access, total room time, contrast agent usage, radiation exposure, and adverse events (AEs). Of 617 patients undergoing SCPC, 409 (66%) underwent at least one advanced diagnostic imaging study in the 60 days prior to surgery. Seventy-eight of these patients (13%) were analyzed separately because of a concomitant cardiac intervention during CC. Of 331 (54%) with advanced imaging and without catheterization intervention, diagnostic CC was most common (59%), followed by CT (27%) and CMR (14%). Primary modality varied significantly by institution (p < 0.001). Median time between imaging and SCPC was 13 days (IQR 3-33). Anesthesia/sedation varied significantly (p < 0.001). Pre-procedural vascular access did not vary significantly across modalities (p = 0.111); procedural access varied between CMR/CT and CC, in which central access was used in all procedures. Effective radiation dose was significantly higher for CC than CT (p < 0.001). AE rate varied significantly, with 12% CC, 6% CMR, and 1% CT (p = 0.004). There is significant practice variability in the use of advanced diagnostic imaging prior to SCPC, with important differences in associated procedural risk. Future studies to identify differences in diagnostic accuracy and long-term outcomes are warranted to optimize diagnostic protocols.

Multi-institution Assessment of the Accuracy of Cardiac Computed Tomography in Preparation for Superior Cavopulmonary Connection

BACKGROUND

Patients with single ventricle (SV) congenital heart disease (CHD) undergo several interventions in the first years of life. Advanced diagnostics are required for interstage assessment of anatomy, but are associated with significant diagnostic risk. We sought to evaluate image quality, risk, and accuracy of cardiac computed tomography (CCT) for evaluation of anatomy prior to superior cavopulmonary connection (SCPC) compared to surgical findings across 2 institutions.

METHODS

A retrospective evaluation of image quality, risk, and accuracy of pre-SCPC CCT was performed at 2 institutions between January 1, 2010 and September 30, 2016.

RESULTS

CCT was performed in 90 SV CHD patients with a median age of 4.03 months (interquartile range [IQR] 3.36, 5.33) prior to SCPC. Image quality was optimal (84%) or good (16%) in all patients, without significant discrepancy compared to surgical findings. 7 patients (8%) required interventional cardiac catheterization subsequent to CCT and before surgical intervention. 49% of scans were performed without sedation, 43% of scans were performed with mild to moderate sedation, and 8% of scans were performed with general anesthesia. The median total procedural dose-length product (DLP) was 18 (IQR 14, 26) mGy*cm, estimating an age adjusted radiation dose of 1.4 millisievert (mSv). One minor (1%) adverse event was reported within 24 h of the CCT. Surgical complications were unrelated to the presurgical findings.

CONCLUSIONS

CCT for pre-SCPC evaluation is safe, with excellent accuracy for anatomy at the time of surgical intervention across 2 institutions. In select patients, noninvasive evaluation with CCT may be indicated.

Pre- and post-operative cardiovascular CT in Stage I single ventricle palliation

OBJECTIVES

The aim of this study is to describe clinical utility of low dose cardiac computed tomography (CT) in the evaluation of single ventricle physiology before and after Stage I palliation.

BACKGROUND

Despite the increased utilization of CT imaging and advancement of CT technology, there are limited studies describing the routine clinical use of cardiac CT and radiation dose parameters in the single ventricle Stage I palliation.

METHODS

This single center, retrospective study included 57 infants with single ventricle physiology who underwent cardiac CT scans between January 1, 2016 and November 30, 2020. Patients' demographic information, diagnosis, indication, total dose length product (DLP), computed tomographic dose index volume (CTDIvol), cardiac CT findings and intraoperative or intraprocedural findings were reviewed. Estimated effective radiation dose was calculated using a previously published conversion rate.

RESULTS

The studies were performed using different generations of CT scanners over the 4 years period: Somatom AS 128, Somatom definition edge, Somatom Force (Siemens Medical Solutions). The studies performed with dual source scanner with prospective gated technique have lower radiation dose exposure with median effective radiation dose of 0.32 mSv.

CONCLUSION

Pre- and post-operative cardiovascular CT in Stage I single ventricle palliation using newer generation scanners with prospective gated technique can be done with minimal radiation exposure and good image quality. Cardiac CT is a powerful imaging modality for better management planning in this group of patients.